Osteoarthritis is a degenerative joint disease that is extremely prevalent in society. It affects more than 25% of Americans above the age of 18 years. According to July 2020 publication by the Centers for Disease Control (CDC), osteoarthritis affects approximately 32.5 million Americans. One of the organs that is most affected by osteoarthritis is the knee. Over the years, we have developed non-surgical treatments, such as physical therapy (PT) and injections, and surgical treatments, such as total knee arthroplasty (TKA) and arthroscopic lavage, for knee osteoarthritis (KOA). If a patient fails with non-surgical options, which are tried first to avoid the risks of surgery, the patient may be considered for knee surgery. This article will investigate the different non-surgical options and TKA as treatment options for KOA based on current literature. The goal of this paper is to be a comprehensive resource for physicians and patients with KOA to make an informed decision.A systematic literature search was conducted using PubMed. The search terms were based on the type of treatments for KOA. To find articles that compared TKA to non-surgical treatments, the terms included “osteoarthritis”, “total knee”, and “non-surgical treatments,” in combination. For other non-surgical treatments such as PT, weight reduction, and injections, a combination of the treatment, “osteoarthritis”, and “knee” were included in the search. For the tier 1 process, any randomized controlled trials were included. Any case reports, observational studies, and cross-sectional studies were eliminated from the search. For the tier 2 review process, any articles that did not have relevance to the topic were eliminated after reading the abstracts of the articles.After review of the literature, the data seem to suggest that TKA with 12 weeks of non-surgical treatment improved pain and functionality of the knee more than just 12 weeks of non-surgical treatment when followed up at 12 and 24 months. However, non-surgical treatment before TKA delays the need for surgery. Supervised PT, either in a group or individual format, has been shown to delay TKA in 95% patients in the group that received PT at the end of one year. In addition, weight reduction has been shown as an effective strategy to improve pain and functionality in KOA patients, which decreases the urgency for surgery. Furthermore, platelet-rich plasma (PRP) injections have been shown to have long-term symptomatic relief for KOA compared to hyaluronic acid (HA) and corticosteroid injections. However, HA and corticosteroid injections are beneficial in treating KOA more than receiving no treatment.Physicians often have difficulty deciding whether to pursue conservative or surgical treatment for patients with KOA. The non-surgical treatments explored in this review - PT, injections, and weight reduction - can provide symptomatic relief and, in some cases, delay the need for surgical intervention. However, based on some randomized clinical trials mentioned in the article, patients receiving TKA have more relief, better quality of life, and improved functionality compared to non-surgical therapy. However, a critical review of this important field of debate shows that there are limited randomized controlled studies comparing the effectiveness of TKA and non-surgical treatments for KOA. We believe that this controversial topic needs further clinical investigation. Osteoarthritis is a chronic condition that involves degeneration of the articular surface of a joint. In addition to degeneration involving the articular cartilage, it also involves other degenerative changes such as ligamentous laxity, periarticular muscle weakness, osteophyte formation within the joint, swelling, and inflammation in the joint . AccordiThis article was previously presented as an abstract at the 2021 American Osteopathic Academy of Orthopedics Annual Spring Meeting on April 29, 2021.MethodsA systematic literature search was conducted using PubMed. The search terms were based on the type of treatments for KOA. To find articles that compared TKA to non-surgical treatments, the terms included “osteoarthritis”, “total knee”, and “non-surgical treatments,” in combination in “All Fields”. For physical therapy (PT), the search terms were “physical therapy”, “osteoarthritis”, and “knee” in the article titles. For weight reduction, the search terms were “weight loss”, “osteoarthritis”, and “knee” in the article titles. For injections, the search terms were “injections”, “osteoarthritis”, and “knee” in the article titles. For the tier 1 process, any randomized controlled trials were included. Any case reports, observational studies, and cross-sectional studies were eliminated from the search. For the tier 2 review process, any articles that did not have relevance to the topic were eliminated after reading the abstracts of the articles  who had received manual PT with supervision had 55% improvement in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores when compared to the control group, which received sub-therapeutic ultrasound to the knee. The WOMAC pain scale is used to rate the amount of pain the patient has during the following five activities: walking, stair climbing, sitting, lying down, and standing . In addiEven though the participants in the trials were randomly assigned to individual PT, group PT, and control arms, there was a significant difference in pain and functional improvement for PT groups when compared to the control group. There are many forms of PT. One of them includes aquatic therapy. In a randomized clinical trial with 71 volunteers, the data suggest that going through a six-week aquatic therapy program reduces pain significantly and improves physical function, strength, and QOL than receiving no treatment for KOA .In addition to various types of PT, there are various methods of delivering the service, such as group-based PT, internet-based exercise training, and tele-health based PT. In a study by Allen et al., no significant difference was reported in WOMAC scores between group PT vs. individual PT in patients with symptomatic KOA Figure  16]..16].Furthermore, in a study with 350 participants with symptomatic KOA, the data showed no significant difference between in-person PT, internet-based exercise training, and wait-list group when the WOMAC scores were measured at four months and 12 months, although there was an improvement in the WOMAC scores over time . In anotWeight reductionMany randomized clinical trials have been conducted to investigate and assess the effectiveness of weight loss on KOA. There are many studies that back up the fact that weight reduction has been shown to significantly improve symptoms associated with KOA, especially when measured with WOMAC scores -23. One Furthermore, a study found that reduction in body fat % was most strongly associated with delta score for KOA than other variables such as weight loss, number of steps per day, and others .In addition to determining benefits of weight loss, there are studies that determined what method can be used for weight loss and resulted in better KOA symptoms. Some studies found that patients who were in the diet and exercise program treatment group did better than patients who were only doing diet program or just exercise Figure  29,30].,30.29,30However, another study found that diet and exercise regime is not suitable for every patient. For some patients, diet only treatment improved WOMAC scores, especially if their baseline weight was above 109.35 kg and their waist circumference was above 90.25 cm . SimilarFurthermore, there are different modalities of delivering the weight loss regime such as in-person instructions or tele-health-directed regimes. A study conducted in Australia compared the outcomes of telephone-based weight loss support for patients with KOA with the control group (no treatment). At the end of six months, the results showed that the telephone-based weight loss support did not significantly reduce knee pain intensity or weight in patients with KOA compared to the control group .InjectionsMany kinds of injections are available for treating KOA. Some of the major ones include cortisone injections, hyaluronic acid (HA) injections, and platelet-rich plasma (PRP) injections based on our database search. There are many kinds of cortisone injections, and two of them include triamcinolone hexacetonide and methylprednisolone acetate injections. A study found that both these cortisone injections were effective in improving pain and function of symptomatic KOA with Kellgren-Lawrence score of 2 or 3 for up to 24 weeks post-injection Figure  34]..34].Corticosteroid injections given intra-articularly are safe and efficacious even for long-term use according to a study conducted in 2003. The study measured the outcomes of corticosteroid injections at one year and at two years since the onset of initial treatment. It concluded that long-term use of corticosteroid injections for KOA is efficacious and safe in KOA with no deleterious anatomical deformity in the knee. In addition, repeated corticosteroid injections provide pain relief for individuals with KOA . In anotIn addition to cortisone injections, patients also receive HA injections. HA injections are effective in reducing pain and improving functionality in individuals with KOA. The efficacy of intra-articular hyaluronan injections was tested over 20 weeks. Patients with KOA who received hyaluronan injections had pain relief and no adverse effects compared to patients who received placebo injections . In a 40PRP injection is another type of injection that is given for KOA. In a 2015 study conducted on 50 patients with KOA, PRP injections showed improvement in KOOS scores over the course of 12 months after the initial cycle (each cycle included three injections), with further improvement at 18 months with repetition of the treatment annually . In a moHowever, to determine which injections are better for KOA, there have been many studies that compared the efficacies of these different injections. The efficacies of PRP and HA were measured in a five-year double-blind randomized controlled trial. A total of 192 patients randomly were assigned to PRP injection and HA injection groups, and the results were measured at two, six, 12, and 24 months, and the mean was 64.3 months. There was no significant difference between HA and PRP injections when International Knee Documentation Committee (IKDC) scores were measured. However, PRP had a significantly lower rate of re-intervention at 24 months compared to HA . SimilarOn the other hand, combination of the injections has been proven to be more helpful than providing just one type of injection. In a 2022 study, patients were treated with either HA injections or corticosteroid + HA injections. The group that received corticosteroid + HA injections had better WOMAC scores over the course of six months than the group that received just HA injections .In addition, a study by Huang et al. compared the effectiveness of cortisone injections, HA injections, and PRP injections. There was no significant difference between the WOMAC scores between the injections at three months. However, PRP injections had better outcomes when WOMAC scores were measured at six, nine, and 12 months after treatment .Total knee arthroplastySeveral studies were conducted that measured different variables to compare the effectiveness of TKA with effectiveness of non-surgical treatments. One of the studies randomly assigned 100 patients with KOA and Kellgren-Lawrence score ≥ 2 to receive either total knee replacement with 12 weeks of non-surgical treatment post-surgery or just 12 weeks of non-surgical treatment only. Non-surgical treatment included instructions on exercise, dietary intake, insoles, education on the characteristics of osteoarthritis, and pain medication to be taken as needed. They measured the outcomes at baseline and at 12-month mark. The variables measured include the four subscales of KOOS scores, including pain, symptoms, AOD, QOL, and sports and recreation, and all these scores were measured out of 100 (1 being worse symptoms and 100 being no symptoms). They also measured the timed up and go test  and completed the EuroQol Group 5-Dimension Self-Report Questionnaire (EQ-5D). Most of the patients in the research had an average BMI of 32.0±5.8 (TKA group) and 32.3±6.2 , which is considered class I obesity according to CDC . At the In another study, using similar patient cohort and design from Skou et al., there were other variables that were measured at baseline and at the three-month mark. These variables include pain sensitization assessed as pressure-pain thresholds at the knee  and the lower leg (spreading sensitization), peak pain intensity in the previous 24 hours, pain intensity after 30 minutes of walking, pain location and pattern, spreading of pain on a region-divided body chart, and pain medication use. The study found that the patients who had a total knee replacement followed by three months of non-surgical treatment had more reduced localized and spreading sensitization than the patients who only had three months of non-surgical treatment. However, the outcomes for pain intensity, pain location and pattern, spreading of pain, and use of pain medication were worse for patients in the surgical treatment group compared to the non-surgical treatment group .In another study, 200 patients who had moderate-to-severe osteoarthritis, as determined by the surgeon, were selected. Of the 200 patients, only 100 patients were deemed eligible to receive TKA (they needed to be deemed eligible by a surgeon and have a Kellgren-Lawrence score of ≥2), and the other 100 patients were not eligible for TKA. From the 100 patients who were eligible for TKA, 50 patients were randomly assigned to receive TKA with 12 weeks of non-surgical treatment following surgery, and other 50 patients were enrolled in 12 weeks of non-surgical treatment . Of the patients who were not eligible for TKA, 50 patients were randomly assigned to receive supervised non-surgical treatment for 12 weeks, and 50 patients were given written instructions to do the non-surgical treatments at home for 12 weeks. The outcomes were measured at baseline, three months, six months, 12 months, and 24 months using the KOOS scores. The results showed that the patients who received a TKA followed by supervised non-surgical treatment had twice as much pain relief and functional improvement after two years compared to patients who strictly received non-surgical treatment for 12 weeks Figure  59]..59].Results and discussionThere are many risk factors that contribute to development of KOA. One of those risk factors is meniscal tears. In an eight-yearlong midlife cohort (35-65 years of age) study, it was found that changes in meniscal tears are highly associated with KOA and part of the KOA causal pathway . ObesityThere are many different treatments for KOA. PT is one of the common non-surgical treatments for KOA. PT is effective in delaying surgery for KOA . HoweverWeight reduction is another non-surgical treatment for KOA, especially since obesity is one of the risk factors for KOA. Weight reduction improves pain and functionality associated with KOA -23. MoreThe final non-surgical treatment explored in this paper is injections. There are different kinds of injections given for KOA. Receiving injections for KOA has better symptomatic improvement than receiving no treatment at all ,55. HoweThe final treatment discussed in this paper is TKA. The randomized controlled trials discussed in this paper suggest that performing TKA with 12 weeks of non-surgical treatment provides better functionality and more symptomatic relief than only non-surgical treatment for 12 weeks for KOA with a Kellgren-Lawrence score of >2 ,46. SincThe many treatment options warrant difficulty in deciding between non-surgical and surgical treatment for KOA. The data indicate that patients receiving TKA with post-operative management  have more symptomatic pain relief, better performance at sports and recreation, and increased QOL and ADL compared to those receiving only non-surgical treatment for KOA at the 12-month follow-up . In addiLimitationsThere are some limitations in this literature review. Because of the limited availability of randomized controlled trials, the choice between non-surgical and surgical treatment for moderate-to-severe KOA cannot be determined with confidence. PT is usually a treatment option that is recommended for early stage KOA, and TKA is often recommended for end-stage KOA. There is no equal comparison of the treatment options at both extreme stages of KOA. In addition, the article does not address treatment options for young patients, since in most cases, TKA is not recommended in young patients (<25 years old) because of increased need for another TKA after 10 years . FurtherPhysicians often have difficulty deciding whether to pursue conservative or surgical treatment for patients with KOA. Many non-surgical treatment options such as PT, weight loss, and injections have been shown to be effective in the management of mild-to-moderate KOA. Based on articles that compared TKA and non-surgical management for moderate-to-severe KOA, patients receiving TKA have more relief, better QOL, improved functionality, and potentially quicker return to work compared to non-surgical therapy alone. However, a critical review of this important field of debate shows that there are limited randomized controlled studies comparing the effectiveness of TKA and non-surgical treatments for KOA. In addition, many studies that were randomized controlled trials on non-surgical and surgical treatments had cohorts that were below 100 participants, which limits the generalizability of the studies since the cohort may not account for all the extraneous variables that can affect the study. We believe that this controversial topic needs further clinical investigation.


P ≤ 0.001). Patients with painful diabetic neuropathy exhibited an overall loss of function profile on quantitative sensory testing. However, within the painful diabetic neuropathy group, cluster analysis showed evidence of greater spinal disinhibition associated with greater mechanical pain sensitivity, relative heat hyperalgesia and higher ratings of spontaneous burning pain. These findings support spinal disinhibition as an important centrally mediated pain amplification mechanism in painful diabetic neuropathy. Furthermore, our analysis indicates an association between spinal disinhibition and a distinct phenotype, arguably akin to hyperpathia, with combined loss and relative gain of function leading to increasing nociceptive drive.The dominant sensory phenotype in patients with diabetic polyneuropathy and neuropathic pain is a loss of function. This raises questions as to which mechanisms underlie pain generation in the face of potentially reduced afferent input. One potential mechanism is spinal disinhibition, whereby a loss of spinal inhibition leads to increased ascending nociceptive drive due to amplification of, or a failure to suppress, incoming signals from the periphery. We aimed to explore whether a putative biomarker of spinal disinhibition, impaired rate-dependent depression of the Hoffmann reflex, is associated with a mechanistically appropriate and distinct pain phenotype in patients with painful diabetic neuropathy. In this cross-sectional study, 93 patients with diabetic neuropathy underwent testing of Hoffmann reflex rate-dependent depression and detailed clinical and sensory phenotyping, including quantitative sensory testing. Compared to neuropathic patients without pain, patients with painful diabetic neuropathy had impaired Hoffmann reflex rate-dependent depression at 1, 2 and 3 Hz ( et al. report that patients with painful diabetic neuropathy and evidence of spinal disinhibition, demonstrated by impairment of Hoffman reflex rate-dependent depression, display a mechanistically relevant pain phenotype. This phenotype, akin to hyperpathia, exhibits a combined loss and relative gain of function leading to increased nociceptive drive.Marshall   The symptoms that dominate can vary dramatically between patients, and it is not yet established whether signs and symptoms change with progression of neuropathy.2 The recent systematic application of sensory phenotyping using quantitative sensory testing (QST) has enabled stratification of patients with DPN into clusters of characteristics and has been proposed to potentially segregate patients based on underlying physiological mechanisms.3-6Diabetic peripheral neuropathy (DPN) is characterized by an array of ‘negative’ and ‘positive’ sensory symptoms in which numbness may paradoxically coexist with prickling, stabbing, burning or aching pain.7-10 These features could contribute to spontaneous pain, such as burning pain, as well as hyperalgesia and allodynia. However, preclinical studies have reported diminished release of excitatory neurotransmitters in the spinal cord of diabetic rats during periods of stimulus-evoked behavioral hyperalgesia,12 and QST studies have reported that only a small proportion of patients with painful DPN fit into the ‘irritable nociceptor’ sensory phenotype.13 Indeed, loss of function consistent with a ‘deafferentation’ phenotype is the most commonly demonstrated QST profile in patients with DPN.13 Whilst variability exists within and across these broad sensory phenotypes, suggesting diversity of pain generation or modulation mechanisms, it remains unclear as to how a deafferentation phenotype, with apparent loss of function of nociceptive pathways, leads to pain.It has been widely argued that ‘dying back’ nerve fibre degeneration and/or nerve fibre regeneration may contribute to the development of pain in diabetic and other forms of neuropathic pain by causing nociceptors to become abnormally spontaneously active or to become sensitized (i.e. respond more vigorously to a given stimulus or to a lower strength of stimulus).14 or alterations in descending pain modulation15-17 have been investigated. Whilst imaging studies suggest enhanced descending facilitation,17 evidence of these mechanisms in pain generation in patients with DPN has been inconsistent.19 A further potential mechanism of interest is spinal disinhibition, whereby inappropriate amplification of, or failure to suppress, incoming signals from the periphery leads to facilitation of ascending nociceptive drive—a process that could generate pain despite peripheral loss of function. In diabetic rodents, spinal disinhibition results from a brain-derived neurotrophic factor-dependent reduction in the expression of potassium chloride co-transporter 2 in the dorsal horn of the spinal cord, leading to a shift in the function of ionotropic GABA-A receptors from inhibitory towards excitatory.20 A biomarker for spinal disinhibition in diabetic rodents is impaired Hoffmann reflex rate-dependent depression (HRDD).21 Importantly, interventions targeting the underlying mechanisms of spinal disinhibition in rats both normalize impairments in HRDD and ameliorate behavioral manifestations of pain.22 We have recently translated these experimental findings to the clinical setting by demonstrating impairment of HRDD in subjects with painful DPN,23 indicating that spinal disinhibition may be a dominant pain mechanism in a proportion of these patients.It is increasingly accepted that pro-nociceptive pathophysiological changes occur within the spinal cord in diabetes that could generate or maintain pain. Temporal summation of pain (wind-up)It is currently unknown whether patients with painful DPN and impaired HRDD have a distinct pain phenotype reflecting spinal disinhibition or whether impairment of HRDD is associated with other mechanisms facilitating ascending spinal nociceptive information such as wind-up or impaired descending pain modulation. To further investigate the relationship between spinal disinhibition and pain phenotype, we have explored QST somatosensory profiles and conditioned pain modulation in conjunction with HRDD in a cohort of patients with diabetes, with and without neuropathic pain.This was an observational cross-sectional study. Research Ethics Committee approval was granted (East Midlands—Leicester South Research Ethics Committee reference 17/EM/0076), and written informed consent was obtained from each participant. Study conduct adhered to the tenets of the Declaration of Helsinki. Consecutive patients attending secondary care diabetes clinics at Manchester University NHS Foundation Trust and Tameside and Glossop Integrated Care NHS Foundation Trust between November 2017 and February 2020 were invited to take part in the study. Participants underwent assessment during a single research visit.n = 90/93) were recruited from a previously reported cohort.24 Detailed demographic data including age, gender and ethnicity along with type and duration of diabetes, co-morbidities, medication, height, weight, blood pressure, HbA1c, lipids and renal function were documented. Participants found to have other common causes of neuropathy based on a family history as well as testing for serum B12, folate, immunoglobulins, electrophoresis and anti-nuclear antibody were excluded from the study.Ninety-three patients with type 1 or type 2 diabetes were recruited into the study. The majority  was used to assess the presence of sensory and autonomic symptoms including changes in sweating patterns, diarrhoea, constipation, urinary tract problems, dry eyes, dry mouth, dizziness, hot flushes, palpitations, sensitive leg skin, restless legs, burning feet and sheet intolerance. The Diabetic Neuropathy Symptom Score (DNS) was used as a diabetes-specific simplified scoring system assessing pain, numbness, tingling and ataxia26 with any score above 0 representing an abnormality. The Neuropathy Pain Scale (NPS), a 0-10 pain rating scale, was used to define the severity of symptoms based on patient responses to questions about pain intensity and pain descriptors, for example, sharp, dull, hot, cold, skin sensitivity and itch. Participants were asked to mark on three visual analogue scales (VAS) current pain, average pain over the past 24 h and worst pain over the past 24 h.Participants completed five questionnaires. The Neuropathy Symptom Profile (NSP), a yes or no questionnaire that documents sensory, autonomic and motor symptoms, including weakness, has been validated in patients with DPN24Nerve conduction and H-reflex studies were performed using a DANTEC Keypoint system . Participants were semi-recumbent at 45° with limb temperature maintained between 32° and 35°. Sural sensory amplitude and conduction velocity along with peroneal motor nerve amplitude and conduction velocity were recorded. For H-reflex studies, tibial nerve stimulation was performed using 1-ms square wave monophasic pulses delivered using surface silver–silver chloride electrodes, to the popliteal fossa. Surface silver–silver chloride recording electrodes with a diameter of 9 mm were placed on the long axis of soleus . H-refle27 Images of the corneal sub-basal nerve plexus were captured using the Heidelberg Retina Tomograph 3 with Rostock Cornea Module  following an established protocol.28 For image analysis, six representative images (three per eye) were selected by M.F. and A.K., who were blinded to participant status. Corneal nerve fibre density [total number of main nerves per square millimetre (no./mm2)], corneal nerve fibre length [total length of main nerves and nerve branches per square millimetre (mm/mm2)] and corneal nerve branch density [total number of branches per square millimetre (no./mm2)] were quantified.Corneal confocal microscopy (CCM) was used to quantify corneal small nerve fibre pathology and has been validated against the current gold standard of intraepidermal nerve fibre density.29 The investigators (A.M. and A.G.M.) underwent formal training at the University of Mannheim prior to commencing this study. Tests for thermal sensation were performed at the beginning of the testing paradigm, prior to mechanical assessments. The thermal sensory testing device  was positioned on the skin on the dorsum of the right foot. Cold detection threshold (CDT) and warm detection threshold (WDT) along with cold pain threshold (CPT) and heat pain threshold (HPT) were recorded. The threshold was determined as the arithmetic mean of three results using the difference between measured threshold and baseline temperature (32°C) for CDT and WDT and absolute temperature for CPT and HPT. Testing of the thermal sensory limen was also performed and calculated subtracting the arithmetic mean of the CDT from the arithmetic mean of the WDT. Paradoxical heat sensations were recorded. Mechanical detection threshold was assessed using standardized Von Frey hairs  and calculated using a modified method of limits (geometric mean of five supra and subthreshold stimulus responses). Mechanical pain threshold (MPT), mechanical pain sensitivity (MPS) and wind-up ratio were all assessed using a set of seven pinprick stimulators with standardized intensities . MPT was calculated using a modified method of limits (geometric mean of five supra and subthreshold stimulus responses). The degree of MPS was calculated using the geometric mean of pain ratings for pinprick stimuli, and wind-up ratio was calculated as the arithmetic mean of the pain intensity rating for the series of stimuli divided by the arithmetic mean of the pain intensity rating for the single stimulus. Dynamic mechanical allodynia, the degree of pain sensitivity to innocuous stimuli, was assessed on the dorsum of the right foot using a cotton wisp (exerting a force of 3 mN), a Q-tip (exerting a force of 100 mN) and a soft brush (exerting a force of between 200 and 400 nM), applied in a balanced order and pain ratings recorded. Dynamic mechanical allodynia was calculated as geometric mean of pain ratings. Vibration detection thresholds were recorded using a tuning fork (Rydel Seiffer 64 Hz with fixed weights) over the medial malleolus with the threshold determined by the arithmetic mean of the three values. Pressure pain thresholds were recorded using a pressure algometer  with a blunt contact area of 1 cm² placed on the skin above the abductor hallucis muscle. The threshold was determined as the arithmetic mean of the three recordings. The raw QST data from each test were log transformed and converted into z-scores  to normalize the data for age, sex and body site tested. This transformation enables comparison between cohorts and DFNS reference data29 and allows for the identification of specific QST profiles. Positive z-score values denote a gain in function, and negative z-scores denote a loss of function in each of the parameters.A full QST battery, representing seven tests assessing 13 parameters, was performed on all patients with diabetes using the standardized DFNS testing protocol.z-score for MPS) − (z-score for MPT). This pain differential (MPS-MPT) gave us a value that represents the ‘relative’ gain and loss of function for mechanical pinprick. A high pain differential score represents patients who have a high MPS ‘relative’ to MPT. We also calculated a value for thermal pain differentials: (z-score for CPT) − (z-score for CDT) termed CPT-CDT and (z-score for HPT) − (z-score for WDT) termed HPT-WDT.We calculated a value for mechanical pain differential as  with a blunt contact area of 1 cm² was placed on the skin above the abductor hallucis muscle on the right hand. Pressure was applied with increasing intensity at a rate of 0.5 kg (50 kPa)/s. The patient was asked to indicate as soon as the sensation of pressure changed to an additional painful ‘burning’, ‘stinging’ or ‘aching’ sensation and the value on the algometer recorded. The test was repeated three times with a break of 10 s in between and mean value recorded. A conditioning stimulus using noxious cold was then administered. The left hand of the patient was immersed up to the wrist in a water bath of melting ice water for up to 180 s. The patient was asked to rate how painful this was (0–100) every 15 s. When the patient could no longer tolerate it, their hand was removed from the water bath and the time noted. The test stimuli were then repeated on the right hand (non-submerged) as detailed above and the level of pain intensity rated again. The conditioned pain modulation effect was calculated as the difference (post conditioning stimulus minus pre) in pressure pain thresholds. A positive value indicates efficient conditioned pain modulation.Conditioned pain modulation requires intact descending pathways and has been shown to be attenuated in patients with chronic pain.t-test to compare means between two groups. Results were reported as mean ± standard deviation. Non-parametric data were analysed using Mann–Whitney test between two groups. Results were reported as median with interquartile range. A P-value of <0.05 considered significant. Correlations were performed using Spearman’s rank test and expressed as a coefficient (r) with P-values. A Bonferroni correction was applied to account for multiple comparisons resulting in a significant P-value of 0.0016. A k-means clustering algorithm (SPSS) was used to further investigate associations within the pain cohort, grouping the data set based on HRDD, QST parameters and pain descriptors from the NPS questionnaire.Statistical analyses were performed using Prism 9 statistical software  and IBM SPSS 29 . Data were tested for normality with the Shapiro–Wilk test of normality. Categorical data were analysed using chi-square Fisher’s exact test of association. Parametric data were analysed using unpaired P = 0.018) higher in patients with painless DPN compared to patients with painful DPN.A total of 93 patients with DPN, 37 with neuropathic pain and (VAS > 0) and 56 without neuropathic pain (VAS = 0) were recruited. Within the painful DPN group, seven patients were taking medication to treat neuropathic pain . An additional five patients were taking selective serotonin reuptake inhibitors. Coincidentally, within the painless DPN group, two patients were taking tricyclics. Current, average and maximum pain scores did not differ significantly between patients with type 1 or type 2 diabetes. There was no significant difference for age, gender, ethnicity, body mass index (BMI) and type or duration of diabetes between the pain and no pain cohorts . The HbA31P < 0.001) higher in patients with neuropathic pain compared to those without pain. Symptoms related to pain and hypersensitivity represented the highest proportion of divergent scores between the two groups, with dry eyes, dry mouth, changes in sweating and dizziness on standing increased in the pain cohort  had both nerve conduction parameters within local normative values and CCM parameters within the previously published normative range.n cohort . Of noten cohort  that werz-scores for QST parameters are summarized in z-score for all parameters fell within the normative range of DFNS control data,32 there was evidence of a loss of function for innocuous and noxious thermal and mechanical detection thresholds as well as for MPS. The z-scores for wind-up ratio and pressure pain threshold were within the normative range. z-scores outside the DFNS normative range. Approximately 20% of patients in both the painful and painless DPN cohorts exhibited abnormal loss of function (z-score > −1.96) in mechanical detection and MPT. A smaller number (∼10%) from both cohorts showed abnormal loss of function in thermal detection thresholds. A small minority of patients from both cohorts exhibited a gain in function (z-score > +1.96) in CPT, HPT, MPS, wind-up ratio and pressure pain threshold. The painful DPN cohort showed a significantly greater loss of function of CDT (P = 0.047), mechanical detection threshold (P = 0.037) and MPT (P = 0.013) compared to patients with painless DPN indicating greater cold and mechanical hypoesthesia. Dynamic mechanical allodynia was present to a greater extent in patients with neuropathic pain but did not reach a level of significance  (n = 82), there were no significant correlations between HRDD and individual QST z-scores or with conditioned pain modulation (HRDD recordings were available from 82 patients  as 11 pa≤ 0.001) . Amongstdulation .P = 0.013) greater loss of function in MPT compared to patients with painless DPN, indicating that patients with painful DPN required a stronger stimulus to feel pinprick as painful compared to patients with painless DPN. MPS did not differ significantly between the painful and painless DPN groups. However, patients with the most impaired HRDD amongst those with painful DPN also showed the most gain, or least loss, of function in mechanical pain reporting (Patients with painful DPN demonstrated significantly (eporting .n = 11) and an equivalent number of patients with painful DPN and the most efficient HRDD. This approach was used as no patients with painful DPN demonstrated efficient HRDD outside 2 SD of patients with painless DPN. z-score for MPT was comparable in both groups; most patients exhibited loss of function with reduced ability in detecting a sharp sensation. Patients in the pain group with relatively unimpaired HRDD also demonstrated a large loss of function in MPS. However, in patients in the pain cohort with the most impaired HRDD, MPS was relatively preserved with a less pronounced loss of function, but without a gain of function (n = 14) and HRDD below mean −2 SD of the control group (n = 11), using our previously published normative data from healthy control participants.24 This resulted in similar findings  higher in patients displaying the most impaired HRDD compared to those with the most efficient HRDD    and 3 Hz   . Both wi= 0.028) ; all pat= 0.047) ]. Althours = 0.377, P = 0.048); 2 Hz ; however, this was not significant following Bonferroni correction   and 3 Hz  (There was no significant difference in HPT-WDT between the pain and no-pain groups. Amongst the pain group HPT-WDT was significantly higher in patients with the most impaired HRDD compared to those with relatively unimpaired HRDD ( 0.0226) . Within = 0.007) , althougrs = 0.389, P = 0.037)    ; MPS-MPT= 0.002) . Althoug< 0.001) .n = 38), resulted in a Bonferroni corrected significance value P < 0.001, to account for multiple comparisons. This highly conservative correction runs the risk of a type 2 error and overlooking potential associations.The large number of parameters in the correlation analysis  for segregation into two clusters. Five parameters significantly discriminated between the two clusters: HRDD at 1, 2 and 3 Hz, MPS-MPT and HPT-WDT. NPS3 (burning pain) was close to being significant  exhibited impaired HRDD at all three frequencies, along with a relatively high value for both MPS-MPT (high MPS relative to their MPT) and HPT-WDT  and higher reported scores for burning pain (NPS3). Cluster 2 (n = 21) exhibited intact HRDD at all three frequencies, along with MPS-MPT and HPT-WDT values close to 0, indicating a lack of relative mechanical and thermal hyperalgesia respectively  showed (i) greater MPS, especially when compared to mechanical pain detection, (ii) relative heat hyperalgesia when compared to innocuous warm detection, and (iii) higher ratings of spontaneous burning pain. These initial findings raise the intriguing possibilities that not only this is impaired HRDD in painful DPN associated with a distinct pain phenotype but also this phenotype is mechanistically appropriate for spinal disinhibition.A current major goal of research in clinical pain is to develop individualized treatment strategies based on presumptive or identifiable mechanisms of pain to increase efficacy and reduce side effects. We have previously shown that cohorts of patients with painful DPN have impaired HRDD, a biomarker of spinal disinhibition, when compared to patients with painless DPN and control subjects.13 the dominant QST profile for our patients with DPN was that of loss of function. Whilst only a small minority of patients had thermal threshold parameters outside the normal range, approximately one in five demonstrated loss of function for tests of mechanical sensation. Nerve conduction parameters significantly correlated with the multiple of QST z-scores indicating a relationship between large fibre neuropathy and loss of function. In addition, greater corneal nerve fibre loss was associated with thermal hypoesthesia and mechanical hypoalgesia. We have shown a less marked loss of function than previously demonstrated in large multi-centre sensory phenotyping studies in DPN,13 which most likely reflects the less severe neuropathy in our cohort of patients. Indeed, ∼50% of patients in the Pain in Neuropathy Study (PiNS) had absent sural sensory nerve action potentials. As we were investigating the role of HRDD, our recruitment deliberately targeted patients most likely to have an adequate H-reflex and hence less severe neuropathy. However, of note, the severity of neuropathy was comparable between painful and painless cohorts, allowing valid phenotype comparison between the groups.In line with previous studies,A predicted impact of spinal disinhibition (impaired HRDD) is that a given peripheral input to the dorsal horn of the spinal cord will be less suppressed than in the normal state or even facilitated.Within the painful DPN cohort, we found positive correlations between HRDD, MPS and differential scores for both mechanical and heat thresholds. Whilst correlation coefficients were moderate, this exploratory analysis reveals a consistent relationship suggesting that spinal disinhibition may be associated with a combined sensory detection loss and hyperalgesia profile. In support of these findings, cluster analysis revealed that the presence of a spinal disinhibition sub-group in which impaired HRDD is clustered with mechanical and heat differentials and burning pain.33 Classification of patients based on their sensory profile or phenotype has previously defined three clusters: those with sensory loss, thermal hyperalgesia and mechanical hyperalgesia.5 However, it is likely that these groups are not distinct, with additional nuanced phenotypes to be further defined.34 Indeed, our cluster analysis did not discriminate between the two clusters (with and without impaired HRDD) based on any individual QST parameters. However, the mechanical and heat differential scores were significant segregators. Therefore, the current findings do reveal a consistent theme linking spinal disinhibition to a combined sensory detection loss and hyperalgesia profile. However, future larger scale studies that enable hierarchical cluster analysis of QST sensory profiles will be needed to test this hypothesis.35Patients with painful DPN required greater pinprick force to detect a stimulus as painful. Accordingly, in the absence of central facilitation/lack of suppression, one might expect lower pain scores during the stimulus response function. However, in patients with the most impaired HRDD, all of whom had painful DPN, mechanical pain differentials were higher than in patients with the most efficient HRDD. These findings indicate that when patients with impaired HRDD detect a painful punctate mechanical stimulus, they rate that stimulus as more painful than patients do with preserved/relatively preserved spinal inhibition. It is important to note that ratings of pain intensity relative to stimulus detection were only tested in the mechanical domain and the equivalent tests for cold and heat pain were not performed. In this respect, future hypothesis-driven studies that compare thermal pain threshold and pain ratings as well as the mechanical differential will be of interest. However, despite having equivalent impairment in detection thresholds for innocuous heat, patients with painful DPN who had greater impairment of HRDD showed a relative gain in function for heat pain detection  compared to patients with painful DPN and efficient HRDD. These initial findings, which are arguably akin to hyperpathia, indicate that patients with spinal disinhibition may have a pain phenotype consistent with spinal amplification/reduced suppression. Furthermore, these exploratory findings provide a potential mechanism by which patients with DPN and an apparent deafferented phenotype develop neuropathic pain that can be detected psychophysically. Defined as ‘a painful syndrome characterized by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold’ (IASP), hyperpathia is not easily captured with QST and therefore may be underestimated.19 Indeed, the latter study also showed that conditioned pain modulation was unexpectedly more efficient in patients with painful DPN when noxious heat was used as a test stimulus.19 Further work incorporating different measures of the descending pain modulation system will be required to explore these potential interactions. The circuitry and pharmacology of HRDD exhibits considerable complexity and can be modified by a number of factors.36 It is also possible that other neurophysiological processes within the spinal cord might act concomitantly to modify spinal disinhibition, HRDD and nociceptive signalling in the dorsal horn of the spinal cord. However, there is currently no evidence that potential candidates, such as loss of segmental inhibition due to alterations of primary afferent depolarization, are implicated in animal models of diabetic neuropathy, and recent evidence suggests any effect of primary afferent depolarization on HRDD to be minimal.37Neuropathic pain and particular phenotypic profiles are likely to relate to a complex interplay in the balance between peripheral inputs and central processing. Impairment of HRDD was not associated with a sensory profile suggestive of an irritable nociceptor phenotype. Both within the painful DPN group and across all patients with DPN, there was no significant relationship between HRDD and magnitude of wind-up or between HRDD and conditioned pain modulation. Whilst this suggests the mechanisms underlying spinal disinhibition are not directly related to other spinal processes that putatively result in central pain amplification , it does not exclude an interaction or competition between these mechanisms. For example, an appropriate descending inhibitory control signal acting on a disinhibited spinal cord dorsal horn could be rendered ineffective or even facilitate ascending nociceptive drive. Interestingly, in the current study, the level of conditioned pain modulation measured with a pressure algometer did not differ significantly between patients with DPN with and without pain. This is consistent with recent findings obtained utilizing mechanical test stimuli.38 Moreover, we enrolled patients with mild/moderate DPN as patients with severe polyneuropathy are likely to have an absent or inadequate H-reflex preventing an assessment of HRDD.40 Finally, the study is cross-sectional in nature. Longitudinal studies will be needed to assess the role of spinal disinhibition in evolving pain phenotypes or in the transition to chronic neuropathic pain as well as for the systematic evaluation of the effects of anti-neuropathic pain medications on HRDD, pain and sensory phenotype.Limitations of this study include the collection of pain ratings by a one-time assessment rather than in a diary. Furthermore, patients continued to take their anti-neuropathic pain medication that would be expected to impact on the pain ratings. Treatments with particular anti-neuropathic pain drugs could also differentially alter HRDD that could increase variability or, by normalizing HRDD, have a tendency to underestimate the initial level of spinal disinhibition.41 Furthermore, an initial study indicates that the degree of normalization of HRDD predicts a therapeutic response to gabapentin in patients with painful DPN.38Both HRDD and QST are non-invasive and potentially widely applicable and broadly applicable in a clinical setting. HRDD and the distinct QST profile could be utilized to identify patients with painful DPN in whom disinhibition is a primary mechanism. This could direct mechanism-led therapeutics and drug discovery. For example, pharmacological intervention studies in diabetic rodents using duloxetine normalize HRDD and diminish behavioural indices of pain.In conclusion, we have demonstrated that patients with painful DPN have impairment of HRDD and therefore evidence of spinal disinhibition. Furthermore, our initial findings using detailed pain profiling have revealed that greater impairment of HRDD is associated with higher patient ratings for burning pain and a ‘hyperpathia’ type profile, characterized by a loss of function in mechanical and thermal detection but with relatively high pain sensitivity. Further investigations to confirm and expand these intriguing findings are needed including an exploration of the therapeutic implications of identifying impaired HRDD and the interactions of spinal disinhibition with other peripheral and centrally mediated mechanisms of pain.fcad051_Supplementary_DataClick here for additional data file.


There is still room for improvement of pain management after spinal surgery. The goal of this study was to evaluate adding the erector spinae block to the standard analgesia regimen. Our hypothesis was that the erector spinae plane block will decrease length of hospital stay, reduce opioid need and improve numeric rating scale pain scores.This was a single center retrospective cohort study. We included 418 patients undergoing laminectomy or discectomy from January 2019 until December 2021. The erector spinae plane block was introduced in 2016 by Forero and colleagues and added to our clinical practice in October 2020. Patients who did not receive an erector spinae plane block prior to its implementation in October 2020 were used as control group. The primary outcome measure was functional recovery, measured by length of hospital stay. Secondary outcome measures were perioperative opioid consumption, need for patient-controlled analgesia and numeric rating scale pain scores. Postoperative data collection time points were: at the PACU and after 3, 6, 12 and 24 h postoperatively.p < .001), multiple level laminectomy (with erector spinae plane block 49 h (IQR 31–54), without block 54 h (IQR 52–75), p < .001) and discectomy (with erector spinae plane block 27 h (IQR 25–30), without block 29 h (IQR 28–49), p = .04).There was a significant shorter length of hospital stay in patients undergoing single level laminectomy (with erector spinae plane block 29 h (IQR 27–51), without block 53 h (IQR 51–55), Erector spinae plane block reduces length of stay after laminectomy surgery. Pain management after spinal surgery remains complicated. Preoperative opioid use, is the strongest predictive risk factor for developing poorly controlled pain in spine surgery . AdditioFunctional recovery is the single most important target of recovery after surgery . Since dThe goal of this study was to evaluate adding the erector spinae block to the standard analgesia regimen. This is a retrospective cohort study. Patients who underwent discectomy or laminectomy from January 2019 until December 2021 were included in this study. Since October 2020 the ESP block has been added to the anesthesia treatment. Anesthesiologists with extensive experience in regional anesthesia techniques performed the blocks. Informed consent for the ESP block was obtained at the pre-anesthesia consultation clinic. All patients who underwent discectomy or laminectomy in 2019 and 2020 before the introduction of ESP blockade were used as control group. An informed consent was obtained from all individuals included in the study for use of their data, analysis and publication.All patients underwent lumbar decompressive spinal surgery; discectomy or laminectomy, in the prone position without instrumentation. In the majority of cases, this included L2-3, L3-4 and/or L4-5. Laminectomy was performed through an interlaminar decompression. Bilateral or unilateral approach was chosen depending on the side of complains. Discectomy was performed through an unilateral approach with a classical linear incision. One neurosurgeon (HK) performed the surgical procedure in all patients in this study.This study was designed identically to our previous evaluation of ESP block in patients undergoing posterior lumbar interbody fusion surgery . Briefly−1 (40 ml) for patients under 50 kg.The ESP block was performed as described by Forero et al. and as reported in our previous study on posterior lumbar interbody fusion surgery , 11. We Data was registered in the hospitals patient data management system. The collected information included preoperative data from the pre-anesthesia and surgical consultations, intra-operative registration of medication as reported by the attending anesthesiologist and postoperative documentation of the patient’s condition, including NRS scores, routinely registered by nurses on the PACU and surgical ward. Postoperative data collection time points were: at the PACU and after 3, 6, 12 and 24 h postoperatively. After assessment by the neurologist and physiotherapist, patients were discharged home if they were able to self-care, the pain was manageable and there were no new neurologic deficits.Functional recovery as measured by LOS was the primary outcome parameter. Opioid consumption during the first 24 h post-surgery, the need for PCA and NRS scores were secondary outcome measures. Continuous variables were presented as mean and standard deviation (SD) or median and interquartile range (IQR), depending on normality. Categorical variables were reported as a number or a percentage.p-value < 0.05 was considered statistically significant. All statistical analyses were performed in collaboration with the research department under guidance of Saskia Houterman, statistician.Differences in normal distributed continuous variables between groups were tested using an independent T-test. Differences in not-normal distributed continuous variables between groups were tested using a Mann–Whitney U-test. Differences in categorical variables between groups were tested using a Fisher’s exact test. A The Medical Research Ethics Committees United  (document number W21.024 and AW22.025) approved this study. It was executed according to the Declaration of Helsinki , the Medical Research Involving Human Subjects Act (WMO) and Good Clinical Practice guidelines. To report this study, we followed the STROBE  guidelines.In total 418 patients were included in the study; 223 patients underwent laminectomy of 1 level, 111 patients underwent laminectomy of multiple levels, 84 patients underwent discectomy (Table p < 0.001). Opioids during surgery, on the PACU, oral opioids on the ward and the amount of patients needing a PCA pump were similar for both groups, as were NRS scores at all time-points (Table Patients with an ESP block had a significant shorter LOS (with ESP 29 h (IQR 27–51), without ESP block 53 h (IQR 51–55), p < 0.001). Opioids during surgery, on the PACU, oral opioids on the ward and the amount of patients needing a PCA pump were similar for both groups, as were NRS scores at all time-points (Table Patients with an ESP block had a shorter LOS (with ESP 49 h (IQR 31–54), without ESP block 54 h IQR 52–75), –75, p < p = 0.04. There was no difference in opioids during surgery, on the PACU, oral opioids on the ward and the amount of patients needing a PCA pump between patients with and without an ESP block (Table p = 0.031). NRS scores at 3, 12 and 24 h postoperatively were similar for both groups (Table Patients with an ESP block had a shorter LOS (with ESP 27 h (IQR 25–30), without ESP block 29 h (IQR 28–49), Because of the retrospective character of the study, the amount of morphine used by patients who had a PCA pump was not registered. Therefore a relevant comparison of opioid consumption between the PCA and oxycodone group was not possible. Complications related to the ESP block did not occur. Subgroup analysis for the different levels of surgery was not performed because most subgroups were too small to draw relevant conclusions.This study evaluated the introduction of the ESP block to standard anesthetic care in 418 patients undergoing single and multilevel laminectomy and discectomy. ESP block reduces LOS significantly in all three groups, with the most significant reduction observed in the single level laminectomy group. We hypothesize that the reduction in LOS is due to decreased postoperative lower back pain resulting from intraoperative manipulation of the back muscles. Patients who wake up without soreness or stiffness are able to begin mobilizing sooner, ultimately leading to a shorter length of stay , 14. As For patients undergoing discectomy, the ESP block also lowers the NRS score at 6 h postoperatively. This reduction of NRS 4 to NRS 2.3 lowers pain scores below what is considered bearable pain (≤ 3) and therefore seems clinically relevant although we did not measure a reduction in opioid need. In this study, the ESP had no effect on pain scores in the laminectomy groups and no effect on postoperative opioid consumption in all three groups. This is in contrast to three RCTs aimed at patients undergoing lumbar decompression surgery and laminectomy or surgery for prolapsed intervertebral disc , 18, 19.www.opendisdata.nl, 2019). Implementing this regional anesthesia technique can save yearly up to € 5,000,000 in medical costs.The reduction in length of stay could imply a significant reduction in hospital costs. An occupied hospital bed at a neurology department in the Netherlands has a cost price (including overhead) of approximately €30 per hour . So for single level laminectomy, this is a reduction in hospital costs of €720 per patient and for multilevel laminectomy €150 per patient. In the Netherlands, approximately 6000 laminectomies of 1 level and 4000 laminectomies of multiple levels are performed per year by neurosurgeons (Discectomy and laminectomy can also be done under spinal anesthesia or general anesthesia with an intrathecal injection of morphine by the surgeon at the end of surgery. Intrathecal opioids have been demonstrated to provide excellent pain relief in patients undergoing lumbar laminectomy , 21. HowThis study contains several limitations. Firstly, this is a retrospective clinical evaluation. Therefore there was no power calculation to determine the sample size which limits the generalizability of our conclusions. Secondly, staff followed our in-house protocol which allowed a more liberal anesthesia regimen and resulted in less detailed data registration compared with a strict prospective study protocol. Thirdly, the levels of operation were not homogeneous. As blocks were carried out at the T12 level in all patients and sensory block levels were not measured, there could potentially be varying degrees of block effectiveness. Fourthly, there is a lack of differentiation between pain at rest and pain during movement. This could potentially explain the absent effects on pain scores in this cohort. If individuals with an ESB tend to initiate mobilization earlier, this could potentially result in the production of pain scores comparable to those observed in the resting control group. Fifthly, the possibility of bias and confounding are inherent to a retrospective study design and may impact the ability to draw conclusions. To the best of our knowledge, during the study period the surgical techniques and treatment did not change, and there were no medical or non-medical factors influencing discharge that could potentially introduce confounding variables, such as administrative problems, social challenges, or fluctuations in staffing levels. As this is the initial study assessing the efficacy of ESP block in neurosurgical spine surgery, it highlights the direction for future research, despite the possibility of biases or confounding factors. The results provide a starting point for further determination of the role of ESP block in this field.Implementing the ESP block for laminectomy and discectomy as standard care in our center has caused a significant reduction in length of hospital stay, especially for single level laminectomy, most likely by allowing earlier mobilization.


Sacroiliac (SI) joint dysfunction is a common source of back pain. Recent evidence from different parts of the world suggest that cooled radiofrequency ablation of sacral nerves supplying the SI joints has superior pain alleviating properties than currently available treatment options for SI joint dysfunction.After obtaining institutional review board approval, the medical records of 81 patients who underwent cooled radiofrequency ablation in a single institution and by a single surgeon were analyzed retrospectively. The recurrence of pain, progression to fusion and functional outcomes were noted. The patients were operated on between June 2020 and December 2021, they include 59 females and 22 males, the average age was 55.4 ± 17.3. Follow up was at least 6 months postoperative.22 of the patients had previously underwent lumbar fusions. Follow up period ranged from 6 to 18 months. After radiofrequency ablation, 7 patients progressed to fusions, and 6 patients had to have the procedure done again to relieve their pain. Student t-test was used to compare between preoperative and postoperative values of NPRS  and ODI (Oswestry disability index). It showed significance with P-value < 0.001 in both.Sacroiliac joint radiofrequency ablation is a good option in the treatment of SI joint pain showing good results in the short term follow up period. It is a simple procedure that can be done in less than 30 min and is capable of providing significant pain relief for patients with sacroiliac joint dysfunction. The sacroiliac joint (SIJ) connects the sacrum to the pelvis. Inflammation around that joint from various possible contributing factors such as trauma, pregnancy, and previous lumbar fusion, can cause significant pain and disability –3. CurreCooled radiofrequency ablation is a relatively new procedure that allows cooling of the probes which can achieve a larger tissue lesion area in comparison with its predecessor. This may in turn lead to better outcomes , 14.Our study has one of the largest patient cohort in the literature, with up to 18 months follow-up using cooled radiofrequency ablation. Our aim is to report our results in terms of functional outcomes, therapy failure and recurrence of pain.After obtaining institutional review board approval, the medical records of 81 Australian patients who underwent cooled radiofrequency ablation in a single institution  and by a single surgeon were analyzed retrospectively; recurrence of pain, progression to fusion and functional outcomes were noted. The patients were operated on between June 2020 and December 2021. Follow up was at least 6 months, and at most 18 months follow up. Selection criteria include intractable pain of more than 3 months duration, failure of conservative therapy, exclusion of other causes for the pain, positive SIJ provocative maneuvers , and SIJ intra-articular injection achieving more than 50% relief [The intra-articular blocks were performed by the surgeon and included local anesthetic 1 mL bupivacaine without epinephrine, and corticosteroid (Dexamethasone 2 mg) injected in both upper and lower pole of SIJ. After the procedure, the patients were given a pain diary , consisted of nine probes that emit a current reaching and maintaining a temperature of 60 degrees Celsius for 2.5 min. The procedure was performed under local anesthesia and sedation using propofol. A high flow nasal cannula therapy was used to assure a good oxygen supply in the prone position. High-flow nasal cannula (HFNC) therapy is an oxygen supply system capable of delivering up to 100% humidified and heated oxygen at a flow rate of up to 60 L per minute. This accomplishes a reduction of nasopharyngeal airway resistance, leading to improved ventilation and oxygenation through the application of a positive pressure environment. In addition to providing positive pressure support to the nasopharynx, a high-flow nasal cannula creates a positive end-expiratory pressure to the lower airways. This effect acts similarly to continuous positive airway pressure support in that it applies a splinting force to keep alveolar airways from collapsing under increased surface tensile stresses during exhalation. Additionally, this allows for improved alveolar recruitment, increasing the effective available surface area within the lungs for gaseous diffusion both to and from the blood. Flow rate normally set at 20 L/min to start and titrated as required. It is now routinely used in theatre for pre-oxygenation of potentially difficult airways and for patients positioned prone for procedures requiring sedation.During sedation, Propofol TCI (Schneider model) is titrated in 3 mcg/ml with supplemental opioids such as tramadol 50-100 mg and oxycodone2-4 mg plus a small dose of ketamine (20-30 mg). Doses would obviously be titrated to patient comorbidities. The post op medications consisted of Tapentadol IR 50-100 mg Q4hrly PRN.Eight patients underwent bilateral procedures, while 73 had unilateral ablation. On the right side, 2,4:30 and 6 o’clock for S1 and S2, while S3 only 2, 4:30 o’clock were targeted Our series of 81 patients included 59 females and 22 males, with an average age of 55.4 ± 17.3  decreasing from 7.86 ± 1.48 to1.47 ± 1.37 at 1.5 months. Further pain relief was noted after the ODI (Oswestry disability index) score collected at 3 months postoperatively reduced from 43.3 to 10.67. It showed significance with P-value < 0.001 in both Tables  and 3. OThis study has one of the largest cohorts in the literature. In our series, most patients were females (72.8%), and there was a high prevalence of previous lumbar fusion (27%). This prevalence is not clear, as a lumbar fusion may increase the presence of SIJ dysfunction, but also many patients may be misdiagnosed, especially those who have facet joint arthrosis and were not clinically examined specifically for SIJ dysfunction. The diagnosis in our patients was made after exclusion of other causes, positive provocative maneuvers and SIJ injection test. The pain significantly improved after the procedure as seen on the functional outcomes scores. Any side effects from the procedure resolved in 6 weeks.Multiple authors have found significant benefits when using cooled radiofrequency ablation for the treatment of SIJ compared to the traditional method , 13, 15.The posterior sacral network is made up from contributing branches from L4-L5 dorsal rami and S1 to S4 lateral branches –19. SomeOne way to possibly improve the outcomes is to achieve a larger lesion size. In a recently published overview study of cooled radiofrequency ablation, it was noted that a larger lesion likely contributes to more denervation and reduced chance of missing the nerves. The diaFurthermore, multiple recently published articles using SInergy™ demonstrate benefit in ODI, NPRS, and visual analog scale scores in these patients , 25 In aAs for the secondary effects, the cause of the neuropathic pain and buttock numbness that occurs after ablation is likely due to the middle cuneal nerve, which is formed by sacral lateral branches . The butThe use of HFNC  has multiple advantages when compared to conventional oxygen therapy including the high-flow rates match the patient’s inspiratory flow rates, deliver a constant FiO2, increase the partial arterial pressure of oxygen (PaO2)/FIO2 ratio, the inhaled heated and humidified gas can improve mucociliary motion and sputum clearance, reduced upper airway resistance, reduced work of breathing and amelioration of thoraco-abdominal synchrony .We recognize that there are some limitations to this study. It is a retrospective review study, with no control groups. There was no traditional radiofrequency group to compare with, thus we cannot make a superiority claim of one modality over another. No serious complications were observed in the patients.To conclude, this is one of the largest reported patient cohort showing significant improvement in functional outcomes with cooled radiofrequency ablation for the sacroiliac joint pain. It also notes that the procedure can be repeated with likely increased duration of pain relief.


The aim of this longitudinal clinical study is to analyse and compare according to location, degree and type, the pain presented by patients during their first year of treatment, as well as the quality of oral life after the placement of two types of orthodontic appliances: conventional brackets and removable Invisalign ® aligners.The sample consisted of 140 patients grouped into 2 study groups of 70 patients each. The first group (brackets group- BG), with fixed multibracket appliances, using the MBT technique and a 0.022” slot. The second group , in treatment with removable aligners (IG), using the Invisalign ® system. They were providen with a questionnare where they had to record the degree , the type and location of the pain monthly during the first year of treatment. The second form was the Spanish version of the OHIP-14, oral quality of life questionnaire, which was provided the twelfth month after the start of treatment.In both groups, we found that the most frequent location of pain occurred during the first phase: mandibular for the IG group and maxillary in the BG group. Throughout the whole analysis, the intensity was mild-moderate with lower values in the conventional brackets’ group. The BG group reported acute pain while the IG group reported sensitive pain during the first month; later both reported sensitive pain.There are differences in terms of periodontal pain in its degree, location, and type according to the different orthodontic techniques used.The study was approved by the bioethics committee of the University of Salamanca (USAL_20/516). Much of orthodontic treatments are justified on the basis of improving psychosocial well-being and quality of life. The orthodontist has to provide information to patients about the needs and the results of the treatment, moreover he has to demonstrate responsibility regarding the effectiveness of the orthodontic treatment and the efficient use of resources .Nowadays, patient’s perception is gaining more weight when evaluating the need for a treatment, its planning, and the established clinical aim. In addition, patients are aware of the importance of oral health and the impact that this may have on their lives, so they participate in the choice of the type of appliance to be used in their treatment. The repercussions on their quality of life will depend on their final choice, which will be largely determined by the degree of pain and discomfort presented during the treatment –6.In general, the perception of pain will depend on the patients’ characteristics such as emotional factors, gender or age, as well as their ability to adapt to the situation. Here, aspects such as the way the patients face it or their character in stressful situations will influence. According to different studies, between a 90% and a 95% of the patients have reported discomfort or pain during their dental treatment , 7–11, aAs has been observed in the different studies consulted, after the placement of orthodontic appliances, regardless of the technique used, the peak pain appears 24 h after the start of treatment and, subsequently, decreases , 21–25. According to published studies, there are no gender differences in pain perception , 17, 21.It has been asserted that the level of osseodental discrepancy may affect the response to pain during the alignment process in orthodontic treatment, since the reduction of the interbracket space increases the stiffness of the arch and, as a result, it increases the forces expressed on the teeth . NeverthThe aim of this longitudinal clinical study was to analyse and compare the differences in terms of pain  and the impact on the oral quality of life of patients treated both with multibracket fixed appliances and removable aligners, during the first 12 months of treatment. The null hypothesis of this study is that there are no statistically significant differences in the location, type and intensity of pain described by the patients as well as in the impact on their oral quality of life after treatment with conventional brackets and aligners.A clinical study was carried out in order to analyse pain perception in 140 patients both with fixed and removable orthodontics. All participants were informed about protocols, and they gave their written consent to participate in the study. The study followed the established guidelines by the Declaration of Helsinki for medical research involving human subjects and was approved by the bioethics committee of the University of Salamanca (USAL_20/516).To estimate the sample size, previous research was carried out to calculate the sample size with an error rate of 5% and a confidence level of 95%. The minimum required sample size was considered to be 67 patients for each treatment group. Therefore, the final sample consisted of 140 participants. No patient dropped out of the study during the study. Study participants were selected using non-probability sampling, with efforts made to balance the sample in age and sex between each orthodontic treatment group. They were divided into two groups, all of them treated by the same operator throughout the study:A first group (BG) of 70 patients undergoing orthodontic treatment with multibracket fixed appliances, using MBT technique and a slot of 0.222” .A second group (IG) of 70 patients undergoing orthodontic treatment with removable aligners, using the Invisalign® system.Study participants were selected using non-probability sampling, with efforts made to balance the sample in age and sex between each orthodontic treatment group. For the selection of participants, the following inclusion criteria were followed: adult patients over 18 years who had not received prior orthodontic treatment and with permanent dentition; patients with a negative tooth-size discrepancy (TSALD) between − 6 and − 2 mm in both arches; patients with no missing teeth except third molars; patients with skeletal class I or mild skeletal classes II and III (ANB between 0 and 5 degrees) and patients for whom interproximal reduction (IPR) between 0.1 and 0.5 mm per tooth were planned (in the treatment plan). They had to have a good oral health  and, a good general health . The following exclusion criteria were followed: need for orthodontic surgical treatment; who were taking medication that influences on pain perception ; pregnant; and those patients treated with auxiliary orthodontic appliances.In the multibracket fixed appliance group, both arches were cemented the first day of treatment using a 0.014´´ thermal nickel titanium initial archwire CuNiTi  with 1.3 mm inner diameter elastic ligatures (3 M USA). Revisions were performed every month, changing the CuNiTi archwire section after 4 months (0.016” x 0.022”) and after 8 months (0.019” x 0.025”). In rotations of more than 25 degrees, 0.10” metal ligatures were placed.In the case of patients treated with Invisalign®, after taking impressions with polyvinyl siloxane silicone , using plastic trays on a first visit and the revision/approval of the Clincheck. The aligners were manufactured and then placed during the second appointment according to the attachments prescribed in the treatment planning. Invisalign® patients changed their aligners every 15 days.After the placement of the appliances, the patients received a questionnaire in which they should record monthly (during the first year of treatment): the location of the pain ; the intensity of pain  and the type of pain . Patients were instructed about pain locations, pain intensity or types of pain.The second questionnaire provided to the patients was the Spanish version of the OHIP-14 oral health-related quality of life questionnaire, which was completed the twelfth month after the start of treatment. The OHIP index  is an instrument to assess the impact of oral health on the quality of life of patients. The OHIP presents the ability to assess the frequency with which a person suffers difficulties in performing certain functions or daily activities due to oral disorders .The pain questionnaire was given to the patients to fill out the first 7 days of each month. This was supervised at the monthly visit to the clinic and at the end of the treatment they filled out the OHIP-14 questionnaire. In both cases, the patients were monitored to verify that the questionnaires were being completed at the appropriate time as well as that they were understood and completed correctly by the patients.The software used for data analysis was the statistical package IBM SPSS 25. Techniques and statistical tests applied are described below. To describe the quantitative variables of the sample , the usual descriptors were reported: mean, and standard deviation , as well as line graphs for visual interpretation. In the case of categorical variables of nominal type, frequency and percentage tables were used, in addition to circle graphs. The differences in these variables between the two groups defined by the treatment factor  were analysed to verify patient differences in these characteristics. To study the differences depending on the treatment group in the quantitative variables, the Student’s T test for independent samples was used. In the case of categorical variables, Pearson’s X2 test was used. In all cases, a 95% confidence level was considered.The sample used consisted of 140 patients, 70 in each treatment group  with an average age of 29.36 years (± 9.80), ranging from 20 to 40 years old. In the BG group we find an average age of 26.97 years (± 7.23), being this average higher in IG (31.74 ± 11.39). Regarding gender, of the total sample, 68 were men (48.60%) and 72 women (51.40%). The average of total upper bone-dental discrepancy was − 3.34 (± 1.86) and in the lower arch, -3.42 ( ± = 1.54). We find, therefore, a homogeneous sample in terms of age, gender and bone-dental discrepancy.After analysing the results, it is noted that the average pain level throughout the months of treatment is higher in IG, except for the first month, where BG reports a higher degree of pain. It should be noted here that the IG standard deviation is larger in all cases, indicating that there is greater variability in the degree of referred pain within participants in this group. The highest degree of pain is experienced in the first month of treatment in both groups . From that moment, the pain starts to decrease progressively, month by month, finding an increase in pain in the BG group during the eighth month of treatment (0.57 ± 0.962). For IG this decrease is less pronounced, maintaining a higher level of pain from the second month, compared to BG, and some higher peaks taking place in the sixth (0.926 ± 1.510) and tenth (0.740 ± 1.510) months, compared to that decreasing trend that was found from the first month  and both (anterior and posterior maxillary or mandibular) had less incidence, not exceeding 26%. We noticed that in the maxillary anteroposterior location there are differences in terms of percentage of patients in both groups, finding that patients in the IG group presented a higher percentage of pain during the first months . These differences are decreasing in the following months. In the mandibular arch, this discrepancy was not observed in the anterior (most posterior) location in both groups . This situation is repeated every month of the study. We also observed that the frequencies in the expression of intense pain disappeared in BG from the second month of treatment (0%). In the case of IG, high figures remain, on the one hand, in moderate pain and lower figures in severe pain, but always higher than those of BG. This shows that pain is always greater in IG Table .After analyzing the types of pain reported by the participants, we find that the most described type of pain, in both groups, is sensitive pain (43.5% in BG and 48.6% in IG), followed by throbbing pain ( 28.7% in BG and 29.0% in IG) and acute pain (23.9% in BG and 16.6% in IG). The rest of the types of pain  were grouped together in the “other types” section  and, in the case of IG group, sensitive pain (37%). In the remaining months, in both groups, the most recurrent pain was sensitive pain, with percentages that vary between 40.6% (BG group during the second month) and 55% (IG group during the sixth month). We find it remarkable that after twelve months of treatment, patients still report a high percentage of sensitive pain in both groups, being 54.6% in the BG group and 52.0% in the IG group . The second item with the highest score in BG is physical disability with a score of 1.31 ± 0.941, while in IG concerns to functional limitation with a score of 2.27 ± 1.693. Statistically significant differences in the dimensions of pain, psychic discomfort, psychological disability and social disability are not found. We can affirm that in all items , psychological disability (0.37 ± 0.571), social disability (0.46 ± 0.582) and obstacles (0.03 ± 0.168)) the group that presented the least impact is BG. BG obtained higher scores in pain (2.79 ± 1.605), psychic discomfort (1.03 ± 1.103) and physical disability (1.31 ± 0.941). IG has a greater impact by its total values (7.43 ± 0.652) The IG has a greater impact due to its total values (7.43 ± 0.652) compared to the bracket group but there is no statistically significant difference. However, in the total OHIP there are no statistically significant differences  and removable . The follow-up time of the patients in this study, in terms of pain, is longer compared to other published studies , 43–45. To produce the movement of the teeth in orthodontic treatments we apply, either through brackets and arches or through the aligners, we use various forces that if they are very high (more than 20 g) could cause pain in the teeth , 50, 51.We have not found statistically significant differences, in relation to the gender of the patients, in the level of pain or the impact on their quality of life. In our study the gender ratio is very similar, with 35 men and 33 women in the conventional brackets group (BG) and 35 men and 37 women in the Invisalign® group (IG). Several studies with similar results have been found in which there are no statistically significant differences in the level of pain perceived by men compared to women –56. Howep < 0.004 in aged [Regarding age, the selected patients were adults with an average of 26.97±-7.23 in the fixed appliance group and an average of 31.74 ± 11.39 in the aligners group. The patients were in permanent dentition and gender distribution was very similar: 68 were men (48.60%) and 72 women (51.40%). We find in our study a statistically significant difference with a  in aged . However in aged , 37, 59.After the scientific literature review, we find that most of the authors refer to dentogingival pain with fixed orthodontics and other types of appliances, however, they do not specify its location or focus their study on the comparison of dental pain versus mouth soft tissues pain  , 52, 60.The pains most frequently described by the patients were acute, sensitive and throbbing, being the acute type the most frequent in the brackets group (46.7%), unlike other authors who find that they were throbbing , 45 or sRegarding the degree of pain that patients present during the first year of treatment, we find statistically significant differences in all analysed months. The pain was milder in the brackets group patients compared to those in the aligners group. As in the previous data, we can only compare our results with other studies during the first month of treatment due to the absence of data in the rest of months. Most of the authors consulted find that the degree of pain, with the various orthodontic appliances, moves, during the first week of treatment, in values of a mild-moderate nature , 64, 65.p < 0.01 in the items of functional limitation and obstacles , and in physical disability item (with a higher incidence in the braces group). Azaripour y cols [Discomfort during orthodontic treatment and its impact on oral quality of life are worse in the early phases of treatment and they gradually reduce as the treatment progresses until the final phase , 68–71. r y cols  assertesr y cols , 73, 74.In this study, we protocolized a follow-up time for patients of 12 months. This is the novelty of our study compared to other published studies: pain monitoring during the first year of treatment. The follow-up time of the patients in this study, in terms of pain, is higher than in other published studies, since most of them just analyse the period between the first and fifth week after the start of treatment , 49, 52.One of the main limitations of this study was the sample in reference to the age of the patients, since the study was carried out only in adult patients (between 20 and 40 years old). In the scientific literature, there are studies that conclude that there are no statistically significant differences in the perception of pain when analysing the influence of age , 47, 80.On the other hand, we also consider a limitation in the results of this study, the difficulty in randomization regarding the type of treatment for each patient. In this type of treatment it is difficult to randomize the sample since there are patients who cannot be forced which treatment to have . Carrying out the study on a non-randomized sample, although both treatments are effective in resolving malocclusion, may have its limitations when it comes to assessing the results of pain intensity or quality of life, so in the future it would be ideal to perform it on a randomized sample.After monitoring the patients during the first twelve months of treatment, we find that the patients in the group of conventional brackets (BG) presented a lower degree of pain than the group of aligners (IG) in all analysed periods, although both moved between mild and moderate pain throughout the analysis time. This pain was located mainly in the anterior bimaxillary area (anterior mandibular in IG and anterior maxillary for BG).The most frequently experienced types of pain were acute for BG and sensitive for IG during the first month of treatment. Subsequently, for both groups, the sensitive type was referred with a higher percentage.Regarding quality of life, in the total OHIP, no statistically significant differences were found between the analyzed groups.


The aim was to study the independent risk factors for chronic low back pain after lumbar compression fractures undergoing percutaneous kyphoplasty (PKP), and to establish a nomogram prediction model accordingly. Data were collected from patients with lumbar compression fractures from January 2017 to December 2021 at the Affiliated Hospital of Xinjiang Medical University. Univariate and multivariate logistic regression analyses were used to determine the independent risk factors for chronic low back pain after receiving PKP for lumbar compression fractures, and the corresponding nomogram was established. Receiver operating characteristic (ROC) curves were plotted and area under the curve (AUC) was calculated, and calibration curves and decision curve analysis (DCA) were plotted to evaluate the model performance. A total of 792 patients with lumbar compression fractures were included in the study, and 188 patients had chronic postoperative low back pain, with an incidence of 23.74%. After univariate and multivariate logistic regression analysis, a total of 5 variables were identified as independent risk factors for chronic low back pain after undergoing PKP for lumbar compression fractures, namely having diabetes , preoperative T value < −2.5 SD , multiple lumbar fractures , lumbar compression ≥ 50% , and bone cement leakage . The nomogram for chronic low back pain after PKP for lumbar compression fractures constructed in this study has good predictive accuracy and helps orthopedic surgeons to intervene earlier in patients at high risk of chronic low back pain after undergoing PKP for lumbar compression fractures. Although there are few complications after PKP, some studies have found postoperative re-fracture of the operated vertebral body and leakage of intraoperative bone cement,,14 but there is a lack of studies on chronic low back pain after fracture. Nomogram has been used in many fields, not only for predicting deep vein thrombosis in the lower extremities after fracture but also for predicting post-fracture pneumonia and post-fracture delirium, with good predictive results. We aimed to investigate the independent risk factors for chronic low back pain after lumbar compression fracture undergoing PKP and to develop a nomogram prediction model accordingly.According to studies, with the increase in life expectancy and the aging of the population, lumbar compression fractures have been increasing.This study retrospectively analyzed the data of inpatient surgical lumbar spine compression patients from January 2017 to December 2021 at the Affiliated Hospital of Xinjiang Medical University. Relevant information about fracture patients were collected, including patient gender, age, body mass index, smoking, alcohol, hypertension, diabetes, soft tissue injury, number of fractured vertebrae, lumbar compression ratio, preoperative T value, fracture to surgery time, duration of surgery, bone cement injection volume, and bone cement leakage.First, diagnosis of lumbar compression fracture; second, patients with lumbar compression fracture admitted to hospital within 72 hours after injury; third, PKP performed after admission; fourth, complete preservation of patient information.First, patients with preoperative lumbar disorders; second, patients with combined spinal tuberculosis or spinal tumors; third, patients with previous lumbar compression fractures.Patients were followed up 6 months after surgery in the outpatient clinic or by telephone, and those with a score > 4 according to the visual analog scale (VAS) were included in the observation group and those with a VAS score ≤ 4 were included in the control group.P < .05 from the univariate analysis were included in the multivariate logistic regression analysis and variables at P < .05 from the multivariate logistic regression analysis were identified as independent risk factors for chronic low back pain after receiving PKP for lumbar compression fractures. The screened independent risk factors were plotted in a nomogram in R software, receiver operating characteristic (ROC) curves were plotted and the area under the curve (AUC) was calculated in the training and validation sets, and calibration curves and decision curves analysis (DCA) were plotted to assess model performance.The collected data were randomly divided into a training set (70%) and a validation set (30%) according to the ratio of 7:3 in R (4.2.1) software. The differences between observation and control groups were analyzed univariately in the training set using SPSS 26.0 software, and the chi-square test was used to statistically analyze the count data. Variables screened at A total of 792 patients with lumbar compression fractures were included in this study, and a total of 188 fracture patients had postoperative chronic low back pain, with an incidence of 23.74% of postoperative chronic low back pain. According to the ratio of 7:3, 556, and 236 fracture patients were randomly divided into training and validation sets.In the training set, 15 variables were analyzed by univariate logistic regression analysis, and the results showed that 9 variables were potential risk factors for chronic low back pain, including age, body mass index, diabetes, soft tissue injury, preoperative T value, number of fractured vertebrae, lumbar compression rate, duration of surgery, and bone cement leakage Table .A nomogram was drawn using the screened independent risk factors used to predict the risk of chronic low back pain after receiving PKP for lumbar compression fractures Fig. . ROC cur some patients still have pain in the low back area after PKP treatment, which can have a serious impact on their lives.Although PKP is currently recognized clinically as the safest and most effective method for treating lumbar compression fractures with a low rate of postoperative complications,The current study collected clinical data from patients with lumbar compression fractures over the past 5 years to develop a clinical prediction model for determining the risk of developing chronic low back pain after PKP in such patients. In this study, we used predictors that are common and easily identified in clinical practice and developed this nomogram prediction model based on the 5 independent risk factors identified, and model validation determined that the model developed in this study has good predictive power.,19 have shown that diabetes affects the vascular permeability of patients, causing peripheral microangiopathy, which decreases blood flow to the bone, affecting bone production and bone quality leading to increased fragility. At the same time, the microangiopathy of diabetes can cause changes in bone quality, resulting in brittle bones and fractures. Diabetic patients have inherently unstable blood glucose levels, which can have a very significant impact on the patient postoperative recovery.The results of the study showed that having diabetes is a risk factor for chronic low back pain after receiving PKP for lumbar compression fractures. Studies–24 showed that the greater the degree of vertebral osteoporosis, the lower the bone density values, and the more likely the vertebral trabeculae are to microfracture under stress, thereby stimulating the nerve endings and causing pain. Since osteoporotic microfractures can cause skeletal pain in patients, safe and effective anti-osteoporotic treatment should be administered to patients after surgery, which in turn relieves pain in the low back area.The results of the study showed that patient with osteoporosis is a risk factor for chronic low back pain after receiving PKP for lumbar compression fractures. Studies,26 Postoperatively, patients often experience decreased lumbar spine stability and chronic pain in the lumbar region. For multiple lumbar fractures, traditional open surgery treatment is often recommended, as traditional open surgery treatment is more stable for stabilizing multiple lumbar fractures.The findings show that lumbar multiple lumbar fractures are a risk factor for chronic low back pain after receiving PKP for lumbar compression fractures. The lumbar spine carries all the weight, and an intact lumbar spine structure is the basis for function. In patients with multiple lumbar fractures, the instability of the lumbar spine increases and is less stable compared to a single lumbar fracture, which can only be partially stabilized most of the time with minimally invasive treatment and cannot maintain full stability.–30 In patients with lumbar fractures, the height of the vertebral body has to be restored as much as possible when using bone cement filling. For vertebrae with high compression rates, the amount of bone cement injected should be increased.The findings show that lumbar compression above 50% is a risk factor for chronic low back pain after receiving PKP for lumbar compression fractures. The anterior column of the vertebral body is the main bearer of axial stress in the spine and is the most vulnerable part of the entire spine to collapse. The collapse of the anterior edge of the vertebral body causes changes in the biomechanics of the vertebral body, which in turn stimulates nerve endings causing pain.–33 However, bone cement leakage may occur when cement filling is performed, and the leaking bone cement may irritate the surrounding nerves, resulting in back pain in patients. Therefore, when performing bone cement infusion, the speed of bone cement infusion should be controlled, and the amount of bone cement should be controlled.The findings show that intraoperative bone cement leakage is a risk factor for chronic low back pain after receiving PKP for lumbar compression fractures. It is generally believed that the most important pain relief mechanism of PKP is the restoration of mechanical stability of the fractured vertebral body, the diffusion of bone cement to part or the whole vertebral body through balloon propping and bone cement filling, which increases the strength of the vertebral body, fixes the vertebral microfracture, and enhances stability.However, there are shortcomings in this study. First, because this was a retrospective study, some unavoidable error arises. Second, this is a single-center study conducted at a tertiary referral trauma center, and there is bias in the selection of patients due to more severe fractures or more complex conditions in the admitted patients. Third, this is a risk prediction model developed in a single center, and therefore its validity needs to be validated in further multicenter studies.The nomogram for chronic low back pain after PKP for lumbar compression fractures constructed in this study has good predictive accuracy and helps orthopedic surgeons to intervene earlier in patients at high risk of chronic low back pain after undergoing PKP for lumbar compression fractures.Conceptualization: Guang-hua Deng.Data curation: Guang-hua Deng.Formal analysis: Guang-hua Deng.Funding acquisition: Guang-hua Deng.Investigation: Guang-hua Deng.Methodology: Guang-hua Deng.Project administration: Guang-hua Deng.Resources: Guang-hua Deng.Software: Guang-hua Deng.Supervision: Guang-hua Deng.Validation: Guang-hua Deng.Visualization: Guang-hua Deng.Writing – original draft: Guang-hua Deng.Writing – review & editing: Guang-hua Deng.