During the chronic stage of Complex Regional Pain Syndrome (CRPS), impaired microcirculation is related to increased vasoconstriction, tissue hypoxia, and metabolic tissue acidosis in the affected limb. Several mechanisms may be responsible for the ischemia and pain in chronic cold CPRS.The diminished blood flow may be caused by either sympathetic dysfunction, hypersensitivity to circulating catecholamines, or endothelial dysfunction. The pain may be of neuropathic, inflammatory, nociceptive, or functional nature, or of mixed origin.The origin of the pain should be the basis of the symptomatic therapy. Since the difference in temperature between both hands fluctuates over time in cold CRPS, when in doubt, the clinician should prioritize the patient's report of a persistent cold extremity over clinical tests that show no difference. Future research should focus on developing easily applied methods for clinical use to differentiate between central and peripheral blood flow regulation disorders in individual patients. Complex Regional Pain Syndrome (CRPS) is a painful disorder that usually develops as a disproportionate consequence of trauma. The disorder most commonly occurs in the limbs, and is characterized by spontaneous pain, allodynia and mechanical hyperalgesia, abnormal regulation of blood flow and sweating, oedema of skin and subcutaneous tissues, movement disorders, and trophic changes of skin, organs of the skin, and subcutaneous tissues ,2.Growing evidence indicates that CRPS is accompanied by various abnormalities of the microvascular system, including an increase in the number of capillaries ,4, endotIn an autopsy study of the affected limbs of two patients, we found an increased number of migrated endothelial cells, as well as an increase of eNOS activity in distal dermis specimens, indicating that endothelial dysfunction may play a role in chronic CRPS .In the CRPS diagnostic criteria , a clearAlthough the debate regarding the pathophysiology is still ongoing, the role of excessive regional inflammation, peripheral sensitization of primary somatosensory afferents, and central sensitization of spinal neurons is becoming clear ,2,12,13.The signs and symptoms are related to these mechanisms. Relating the clinical picture to the underlying pathophysiology might help determine the pharmacotherapeutic approach for an individual patient .The clinical picture of CRPS, especially the signs of autonomic dysfunction, and the discovery by Leriche that surgical sympathectomy dramatically improved pain in CRPS supports the important role of the sympathetic nervous system in CPRS etiology . The symIn the acute phase of CRPS, the affected limb is usually warmer than the contralateral limb due to cutaneous vasodilation, and a functional inhibition of sympathetic vasoconstrictor activity has been shown ,25. In tAfter a so-called intermediate phase in which skin blood flow and temperature differences appear to alternate between warm and cold, a large number of patients show a permanent decrease in blood flow and temperature  despite As demonstrated by simultaneous testing of skin blood flow and sweat in one CRPS patient, vascular abnormalities may not solely be the result of a disturbance of the autonomic nervous system. Although sudomotor activity was greater on the affected side, implying higher sympathetic nerve activity, basal blood flow was also greater on the same side. These results suggest that one or more factors increase basal blood flow despite high sympathetic nerve tone on the affected side . Other mSeveral recent studies -40 have 2), and the vasoconstrictor endothelin (ET) [The endothelium, the largest organ of the body, releases agents that regulate vasomotor function, trigger inflammatory processes and affect hemostasis in response to shear stress and hormonal stimuli, such as vasoactive substances . Blood plin (ET) .2, which only plays a limited role as a vasodilator in most vascular beds, is produced from arachidonic acid by cyclooxygenase in response to shear stress and a number of factors that also increase NO production. PGI2 activates adenylate cyclase to increase cyclic adenosine monophosphate (cAMP), also leading to vasodilation [NO is generated from the amino acid L-arginine by three major isoforms of NO synthase, namely neuronal (nNOS), inducible (iNOS), and endothelial (eNOS) enzymes . nNOS andilation ,47.in vivo takes up to one hour [The peptide ET, one of the most potent known vasoconstrictors, is generated by cleavage of a large polypeptide within the endothelium. Of the three types of ET, ET-1 is the most important in vascular tissue, and it acts on endothelin-A receptors on the vascular smooth muscle . Evidencone hour . Vasomotone hour ,52.Endothelial dysfunction (EtD) was first described by Panza as an impairment of the regulation of endothelium on blood vessels . As a prIn vivo, endothelial function may be assessed invasively on resistance arteries by measuring blood flow using strain-gauge plethysmography by studying the effects of acetylcholine or metacholine administration through an intra-arterial catheter [in vivo techniques include fingertip pulse wave amplitude with peripheral arterial tonometry [In vitro, the endothelial dysfunction of isolated resistance arteries dissected from biopsies of gluteal subcutaneous tissue has been studied on a wire or pressurized myograph. A good correlation was found between the endothelial function of small arteries in vitro and FMD of the brachial artery in vivo [Flow mediated dilation (FMD) is an important tool for assessment of endothelial function both in the upper  and the catheter . Acetylccatheter ,59,60. Scatheter . Other nonometry , measureonometry , and floonometry . In vitr in vivo ,65.Several studies have assessed the microvascular endothelial function in CRPS patients with controversial results. Gorodkin et al. used iontophoresis to test endothelial dependent vasodilation with acetylcholine and endothelial independent vasodilation with sodium nitroprusside in 17 CRPS patients and 16 healthy controls. Among the CRPS patients (IASP criteria) 4 were qualified as warm and 13 as cold; the median duration of the symptoms was 5 years (range 3 months to 20 years). No significant differences were observed between both groups or between affected and unaffected limbs .However, these results could not be reproduced by Schattschneider et al., who compared 14 patients with cold CRPS (disease duration 17.6 ± 2.1 months) with 10 healthy controls. In this study, acetylcholine induced vasodilation was significantly reduced on the affected side compared to the contralateral extremity and controls, whereas no differences were observed after application of sodium nitroprusside .Similar results were found in a study by Duman et al., who used the FMD technique to examine 21 patients in a more acute stage of CRPS , and compared the results with 15 healthy controls. Upon evaluation of the brachial artery with Doppler ultrasound, significant differences were observed in the waveforms obtained in the affected compared to contralateral limbs; although not significant, there was a trend of larger dilating responses in the affected limbs .In a small study with 9 patients with CRPS in one upper limb and 9 patients with CRPS in a lower limb, Dayan et al. examined FMD and local vascular reflexes . To measThe results from these four studies suggest that changes in vascular response are found locally only at the side affected by CRPS, while there is no difference between the contralateral side and healthy controls. Whether there is a relation between stage of the disease  or the duration of the disease, and endothelial dysfunction is not yet clear. In discussing the first three trials, Duman  suggesteIn addition to changes in the somatosensory systems, which process noxious, tactile and thermal information, and changes to the sympathetic systems, which innervate skin and somatomotor systems, peripheral changes are detected in CRPS that cannot be explained by the central changes . These pPain is an important symptom in CRPS. Most patients experience an intense, spontaneous, burning pain in the distal part of the affected limb, which is characteristically disproportionate in intensity to the initial event, and increases in a dependent position . SeveralThe various mechanisms by which pain is generated in CRPS are outlined below. The section on ischemic pain is of particular relevance to this discussion, as it closely relates to changes in peripheral blood flow.The neuropathic pain in peripheral tissues may be generated and maintained by peripheral sensory nerve fibers. Quantitative sensory testing studies strongly suggests a role of peripheral inflammation in acute CRPS, and a loss of small fibres in acute as well as chronic CRPS. Acute CRPS patients demonstrated heat pain hyperalgesia, while chronic CRPS (>12 months) showed warm as a well as cold hypoesthesia . OaklandSudeck was the first to describe the classic signs and symptoms of inflammation, including rubor, calor, dolor, tumor and function laesa, in acute CRPS ,84. KoziOur research group compared levels of proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) in plasma and fluids of artificially induced blisters on the CRPS side and contralateral side. There was no indication for inflammation in plasma , which wIn three studies of patients with an intermediate disease duration of 2.5, 2.8 and 3.5 years, the levels of these cytokines were still increased -90. RemaIn rats, during the reperfusion which follows prolonged extremity ischemia, the synthesis of free radicals and pro-inflammatory cytokines leads to inflammatory responses and vasculature injury in the ischemic tissue . This isIn human patients treatment with free radical scavengers can both reduce the risk of developing CRPS -100 and Regardless of the initial pathogenesis, one hypothesis has proposed a vicious circle of altered blood flow that leads to hypoxia, production of free radicals, endothelial damage and further reductions in blood flow . The sloOne of the characteristics of CRPS is the often observed disproportionate severity of the symptoms with the severity of the trauma, along with a tendency to generalize in the affected distal limb but not confined to the innervation zone of an individual nerve . NocicepFunctional pain is defined as hypersensitivity to pain resulting from abnormal central processing of normal input . CRPS paDisuse has often been mentioned in CRPS. In animal studies of immobilization, an increased sensitivity to sensory stimuli, as well as changes at the spinal level that could account for this increase, have been found -113. In A receptors [We investigated the involvement of the vasoactive substances ET and NO during early chronic CRPS. Measurement of NO and ET levels in artificial suction blisters in 29 patients showed a significant increase in ET and a decrease of NO on the affected side compared to the unaffected side, indicating an aberrant NO/ET ratio in the intermediate state of CRPS. This altered ratio results in vasoconstriction and consequently in diminished tissue blood distribution . The rateceptors . As seveeceptors , anal fieceptors ,123, andeceptors , we propeceptors , occurs eceptors .Based on these preliminary results, we decided to test the effect of ISDN in a double blind randomized controlled trial. Twenty-four patients with chronic CRPS in one upper extremity received 1% ISDN in Vaseline or a placebo ointment applied to the dorsum of the affected hand 4 times daily for 10 weeks. The patients participated in a physical therapy program to improve activity. The primary outcome measure was blood distribution in the affected extremity, which was determined by measuring the skin temperature using videothermography. We also measured NO and ET-1 concentrations in blister fluid, assessed pain using the VAS, and determined activity limitations using an Upper Limb Activity Monitor (ULAM) and the Disabilities of Arm Shoulder and Hand Questionnaire (DASH). ISDN failed to produce a significant improvement in temperature asymmetry in chronic cold CRPS patients, and also did not generate the predicted reduction in pain and increase in activity compared to placebo. The results of the active treatment group are shown in Figure To further evaluate the influence of endothelial factors, patients with chronic cold CRPS in one lower extremity were included in a double blind, randomized, controlled trial that investigated the effect of tadalafil on the microcirculation. Tadalafil, a PDE-5-inhibitor known as an effective treatment for erectile dysfunction , functioIn both studies, the results of treatment with study medication was compared to placebo, and, as shown in Figure 2) is lowered and skin lactate is increased in CRPS limbs, alterations in nutritive as well as thermoregulatory blood flow may also be important in CRPS.The results of the static videothermographic measurements should be interpreted with care, due to the dynamic nature of side temperature differences in CRPS ,130,131.Recent evidence suggests that both NO and ET also play a role in nociception exhibited in animals with ischemia-reperfusion injuries. The mechanical allodynia that is observed in rats with a hind paw ischemia-reperfusion injury is relieved by systemic administration of the NO donor 3-morpholinylsydnoneimine chloride (SIN-1) . FurtherA receptors. Of these strategies, only ISDN and PDE5 inhibition have been tested in randomized placebo-controlled trials with CRPS patients. Because these trials included patients with cold chronic CRPS and did not differentiate between central and peripheral dysfunction, the results may not be conclusive for the treatment of endothelial dysfunction.Treatment strategies for endothelial dysfunction in CRPS patients include the substitution of nitric oxide with ISDN, inhibition of PDE5, substitution of ADMA, or blockage of ETCalcium antagonists are used in the treatment of hypertension and angina pectoris, as they bind to the L-type calcium channel in the smooth muscles of the vascular wall, thus reducing the influx of extracellular calcium and resulting in vasodilation. Nifedepine has been examined in two descriptive studies with CRPS patients, and this calcium antagonist was most effective in acute CRPS ,135. In An interesting development occurred in the tadalafil study, when one patient who had not responded to the active tadalafil treatment with an increase of temperature and showed persistent high pain scores was treated with a lumbal sympathectomy. The leg on the CRPS side became warmer, and the temperature increased until it was more than 1°C warmer than the contralateral side. This improvement in temperature (difference) still persists. We consider this an indication that in cold chronic CRPS, both endothelial dysfunction and sympathetic dysfunction may be responsible for ischemia in the cold extremity. Unfortunately, in this patient, the severe pain was unaffected by the sympathectomy, indicating that in CRPS, pain and ischemia may be related in some cases, but an increase in blood flow will not result in less pain in other cases.This observation confirms the result of trials performed by Baron et al. in analyzing skin blood flow demonstrating that sympathetic vasoconstrictor reflexes and pain after surgical sympathectomy show no clear relationship of vascular changes and the success of sympathectomy regarding pain relief . Thus, aIn a study with intermediate CRPS patients (disease duration 2.8 ± 1.4 years), we found a significant increase in IL-6, TNF-α and ET-1 levels in blister fluid in the CRPS extremity versus the contralateral extremity . ET-1 coCurrent research in the field suggests several possible mechanisms responsible for ischemia and pain in chronic cold CRPS. Because of the fluctuation of temperature difference between both hands, even a patient who reports an extremely cold extremity may present no difference in temperature in the clinic or even a warmer CRPS side. In this case, a static video thermographic recording may not show any difference compared to a manual test. Under circumstances of doubt, the clinician should let the patient's report of a persistent cold extremity prevail over clinical tests that show no difference.Several tests have been described to separately investigate the sympathetic and the endothelial function. Until now, these tests have only been used for research purposes. Promising results were found using provocative manoeuvres, like the Valsalva manoeuvre, and the cold pressor test , or inspFuture research should focus on methods to differentiate between sympathetic and endothelial dysfunction for clinical use. Laser Doppler Flow, video thermographic recordings and ultrasound could be used to measure the results of autonomic provocation tests, and flow mediated dilation, in combination with long-term temperature measurements. Investigators should not only focus on blood flow in the skin but also in deep tissues; more information is needed regarding the separate contributions of thermoregulatory and nutritive blood flow.To differentiate between sympathetically maintained pain (SMP) and sympathetically independent pain (SIP), a sympathetic block has been advised , usuallyAs a result of an impressive amount of research over the last few years, our understanding of CRPS has improved considerably. Although some studies have suggested that CRPS is primarily a disease of the central nervous system, alterations have also been found in the peripheral small nerve fibers innervating skin, blood vessels and sweat glands, as well as aberrations in the vascular wall, muscle fibers and other deep somatic tissues, likely as a result of damage by the initial inflammation. Although this article focused on disturbed peripheral blood flow in patients with cold, chronic CRPS, treatment goals are not necessarily only local. In this respect, we agree with Harden, who proposes that the treatment of CRPS should be a systematic and coordinated interdisciplinary approach with a primary goal of functional restoration .The authors declare that they have no competing interests.All authors contributed equally to this article. All authors read and approved the final manuscript.The pre-publication history for this paper can be accessed here:


We wanted to investigate acetabular labral tears and their correlation with femoroacetabular impingement in patients with sports injury.Among 111 patients who were diagnosed with the acetabular labral tears after arthroscopic treatment from January 2004 to December 2007, we selected 41 patients with sports injury. There were 12 cases of Taekwondo injury, 5 of golf injury, 4 of soccer injury, 3 of gymnastics injury, 2 of Hapkido injury, 2 of aerobics injury, 2 of rock-climbing injury, 2 of fitness training injury and 9 of other sports injuries. We checked the subtypes of acetabular labral tears and the accompanying femoroacetabular impingement. For the cases with accompanying femoroacetabular impingement, we investigated the subtypes according to the types of sports, gender and age. At last follow-up, we checked the Harris Hip Score (HHS), the Hip Outcome Score (HOS) sports scale and the percentage of patients who returned to their sports activity.The average age of symptomatic onset was 26 years . The ratio of males to females was 29 : 12. An average duration of the hip pain was 17 months . The degenerative type of acetabular labral tears was the most prevalent with 32 cases (78%), and there were 9 cases (22%) of the partial tear type. Thirty cases (73%) were accompanied by femoroacetabular impingement. The average age of the 23 cases (56%) of the cam-type was 23 years , and it was more likely to occur in men (87%) and for people practicing martial arts such as Taekwondo or Hapkido. An average age of the 5 cases (12%) of the pincer-type was 26 , it usually occurred in women (60%) and for non-martial arts such as golf and gymnastics. There were 2 cases of the mixed type (cam + pincer-type). At 27 months follow-up, the HHS was 61 to 92 points, the HOS sports scale increased 43 to 75%, and the rate of returning to sports was 71%.In spite of the early expression of symptoms and the short duration of the acetabular labral tears, the high rate of degenerative acetabular labral tears in sports patients is likely associated with repetitive injury after the expression of symptoms. Femoroacetabular impingement in sports patients is seemed to be a cause of the early occurrence of acetabular labral tears. Because the possibility of acetabular labral tears is high in femoroacetabular impingement, sports patients may need to undergo early screening for the diagnosis and care of femoroacetabular impingement. Acetabular labral tears (ALT) have been the subject of many studies regarding their pathophysiology, diagnosis and treatment, and their rehabilitation and prognosis.5)The advancement in the diagnostic methods and hip arthroscopy have allowed the lesions of the acetabular labrum that are caused by sports injuries to be diagnosed at an increasing rate and this has promoted discussion concerning the treatment.In addition, ALT has been identified as a cause of hip pain in patients with FAI,14)In this study, we investigated the different types of ALT in athletic patients. We explored the associations between ALT and FAI and we assessed the outcomes of arthroscopic treatment.From January 2004 to December 2007 at our institution, ALT was the definite diagnosis for 111 patients who had undergone arthroscopic treatment under the provisional diagnosis of either ALT or ALT accompanied by FAI, and they were diagnosed using MR-arthrograms and 3D-CT. The patients had complained of acute or chronic pain and they had positive impingement test results. Of these 111 patients, 41 athletic patients were retrospectively reviewed for this study.The mean age of the enrolled patients at the onset of symptoms was 26 years . There were 29 males and 12 females. The mean duration of illness was 17 months .In this study, an athlete was defined as one who participated in a particular sport more than 4 hours a day and 5 days per week for more than 1 year until hip pain developed, and this was regardless of the patient having a professional or amateur status. Twelve patients were involved in Taekwondo, 5 in golf, 4 in soccer, 3 in gymnastics, 2 in Hapgido, 2 in aerobics, 2 in rock climbing, 2 in fitness training, 1 in baseball, 1 in swimming, 1 in inline skating, 1 in cycling, 1 in tennis, 1 in basketball, 1 in yoga, 1 in badminton and 1 in another athletic sport.The patients who complained of hip pain underwent history taking, physical examinations, blood tests and radiography  at the time of the visit.The data obtained during history taking is as follows: the age at the time of the onset of hip pain, the age at the time of initial sports participation, the types of sports, the daily time spent on sports activities, the frequency of participation in sports in a week and the positions that aggravate the hip pain. For making the differential diagnosis, the patients were also asked about their past history of trauma and systemic diseases. The level of pain was rated according to the JOA pain scoring system set by the Japanese Orthopaedic Association: intermittent or continuous severe pain = 0 points, intermittent mild pain or occasional severe pain = 1 point, occasional mild pain = 2 points and no pain = 3 points.1)On the physical examination, if passive flexion, adduction and internal rotation of the hip (impingement test)14)Pain caused by systemic inflammatory disorders such as rheumatoid arthritis and ankylosing spondylitis was ruled out according to the diagnostic criteria.17)For the patients with 0 or 1 point (the JOA pain score), a positive impingement test and suspected FAI based on the plain radiographs despite conservative treatment, an MR-arthrogram was performed for those patients with nonspecific plain radiographic findings, but with suspected ALT on the physical examination. 3D-CT was performed for those patients who met the above criteria and who had an obvious femoral head-neck bump and acetabular retroversion on the plain radiographs. The ALT observed on the MR-arthrogram was graded according to the classification of Czerny et al.18)The ALT patients who presented with severe pain underwent arthroscopy for making the definite diagnosis and treatment. The patient was placed in the supine position under epidural anesthesia or general anesthesia. With the hip in 25° of abduction, traction was applied to the leg in the neutral position. In this position, around 8-10 mm of joint space widening was identified with a C-arm image intensifier. With the aid of a C-arm intensifier, a 15 gauge, long spinal needle was inserted at the anterolateral portal and 20-30 cc saline water was injected into the joint after the identification of the presence of air in the joint. A guide needle was inserted through the spinal needle and a 5 mm trocar was introduced into the joint. The trocar was replaced by the arthroscope, and the acetabulum and femoral head  were observed through it. Anterior and posterolateral portals were additionally used, if necessary, for arthroscopic examination and treatment.The arthroscopically identified ALT was removed. In patients with ALT accompanied by FAI, a bump at the head-neck junction (the cam-type FAI) was removed by a burr (bumpectomy), acetabular retroversion (the pincer-type FAI) was treated with acetabuloplasty and the damage to the acetabular cartilage was done with chondroplasty.According to the modified classification of ALT by Beck et al.,p-values ≤ 0.05 were considered statistically significant.The Harris Hip Score (HHS), the Hip Outcome Score (HOS) the sports scale score and the percentage of patients returning to their preinjury sports were measured before and after the arthroscopic treatment, and during a mean of 27 months  of the follow-up period and these values were compared to evaluate the treatment outcomes. All statistical analyses were done with using the Mann-Whitney U test, which is a non-parametric test. The The most common type of tear was degenerative tear in 32 cases (78%). Partial tear was found in 9 cases (22%) and complete tear was not observed. Of the 41 patients, FAI accompanied the tear in 30 patients (73%): there were 23 cases (56%) of the cam-type FAI, 5 cases (12%) of the pincer-type FAI and 2 cases (5%) of the cam + pincer-type FAI .p = 0.023).For the 23 patients with the cam-type FAI, the mean age at the onset of symptoms was 23 years  and there were 20 (87%) males and 3 (13%) females. The cam-type FAI was found in 9 patients (64%) out of the 14 patients with injuries that were due to martial arts activities such as Taekwondo and Hapgido, and the cam-type FAI was found in 14 (52%) out of the 27 patients who were injured during non-martial arts activities. Therefore, the cam-type FAI appeared to be more common in those patients who were involved in martial arts activities (p = 0.041)  and there were 2 (40%) males and 3 (60%) females. Four (15%) of the 5 cases were found in patients who had been involved in non-martial arts activities such as golf and gymnastics and 1 (7%) was found in a martial arts athlete. Therefore, the pincer-type FAI seemed more prevalent in non-martial arts athletes (= 0.041) .The prevalence of cam-type symptoms was higher in the martial arts athletes while the prevalence of pincer-type symptoms was higher in the non-martial arts athletes .p = 0.032) (p = 0.033). The number of patients who recovered to play sports at a less intense level or they changed their type of sports activities was significantly high among the martial arts athletes (p = 0.018): 5 (36%) of the martial arts athletes and 4 (15%) of the non-martial arts athletes (p = 0.018). The number of patients who quit playing sports after surgery was larger among the martial arts athletes (p = 0.027)  . Of the = 0.027) : 2 (14%)Since Altenberg24)ALT frequently occur in relatively young patients in their 20s to 40s and it usually causes piercing pain deep in the inguinal area in the squatting position, when sitting and standing from a chair and when getting on and off a vehicle.Kim and Azuma28)There are many reports on ALT combined with FAI in athletes.20)Therefore, we now better understand the mechanism of pain in ALT patients. Athletes who have FAI without pain can go through intermittent pain when a partial acetabular labral tear occurs due to repetitive stimuli, which also leads to a degenerative tear that causes constant pain.To interrupt such a mechanism of pain, arthroscopic treatment of FAI is used, and FAI the main cause of ALT. This procedure attempts to prevent ALT by removing the bony protrusion  that causes ALT and repair the damage to the acetabular cartilage. However, considering that the efficacy of preventive treatment has not been fully examined, we believe that more studies that focus on its efficacy should be conducted. As of now, performing a screening test for asymptomatic FAI on young athletes and making sure they are aware of the risk of ALT appears to be the proper approach. In the current study, no patients underwent preventive treatment and ALT occurred in all of the patients. To treat this, we performed arthroscopic bumpectomy or acetabuloplasty, and we obtained remarkable outcomes.We subdivided ALT into the degenerative, partial and complete tears.Byrd et al.According to Philippon et al.,In this current study, a statistical significance was found for improved HHS and HOS sports scale scores following arthroscopic treatment in all the cases. However, when the treatment results of martial arts players and non-martial arts players were compared, the former group was less likely to resume their preoperative sports and they were more likely to change or quit sports . We attrConclusively, we believe that professional athletes and would-be professionals with hip pain should under go screening tests for ALT and FAI. In addition, we recommend that the patients diagnosed with ALT undergo arthroscopic examination and treatment for symptomatic improvement and resumption of their preoperative sports activities.


A number of different methods have been proposed for pain relief in cancer patients with bone metastases, each with different indications, contraindications and complications . The ideal treatment has to be fast, safe, effective and tolerable for the patient. CT-guided radiofrequency (RF) ablation may fulfill these criteria. Our experience in the treatment of 30 patients (34 lesions) with painful bone metastases using RF ablation was assessed. There was a significant decrease in the mean past-24-h Brief Pain Inventory (BPI) score for worst pain, for average pain and for pain interference during daily life  4 and 8 weeks after treatment. There was a marked decrease (3 out of 30 patients 4 and 8 weeks after treatment) in the use of analgesics. CT-guided RF ablation appears to be effective for treatment of painful bone metastases. Painful bone metastases are a common cause of morbidity in patients with metastatic cancer, especially when combined with possible neural compression and pathologic fractures. Several solid cancers are associated with bone involvement, most often, prostate and breast. Thirty to seventy percent of cancer patients develop bone metastases . They inA number of treatment methods are available that have variable success and complications. Radiation therapy is the preferred treatment in this setting, but other modalities such as chemotherapy, hormonal therapy, radiopharmaceutical therapy and surgery—alone or in combination with non-steroid anti-inflammatory drugs (NSAIDs), opioids and adjuvant drugs—are used for pain palliation –3.Radiofrequency (RF) ablation is a relatively new method for the treatment of painful bone metastases. Previously, tumour ablation was performed with percutaneous ethanol injection under CT guidance . AdminisRadiofrequency ablation has been employed for the treatment of hepatocellular carcinoma (HCC), liver metastases, renal and lung tumours, as well as for the treatment of osteoid osteoma, for which it has become the treatment of choice –3. CompeThirty patients were retrospectively identified. There were 19 men and 11 women. Their ages were between 47 and 91 years (mean ± standard deviation [SD]: 66.53 ± 10.56 years). The patients had bone metastases, which were treated with RF ablation under CT guidance, at our hospital, over a period of 4 years. All treated lesions were osteolytic with a combination of bone destruction and a soft tissue mass. In 26 there was a solitary lesion, and in 4 patients there were two such lesions, resulting in a total number of 34 metastases. Bone metastases were diagnosed by bone scintigraphy and spiral CT. The diagnosis was confirmed with a core biopsy obtained at the beginning of the procedure. Their topographical distribution and the originating primary malignancies are presented in Table Lesion diameter was between 1 and 14 cm (mean ± SD: 3.9 ± 2.6 cm). For sizes over 3 cm, two or more electrode placements were needed (with a maximum of five). Previously obtained imaging examinations were evaluated for lesion characteristics and feasibility of electrode positioning and ablation. Lesions located in proximity to the spinal cord and major nerves (less than 1 cm) were excluded from RF treatment. Patient selection criteria are summarised in Table Physical examination was performed by the oncologist and in collaboration with the radiologist performing the ablation. Pain was assessed with the Brief Pain Inventory (BPI) The use of analgesics was recorded the day before the procedure.Before the procedure blood cell count and blood clotting analysis were performed. Minimal requirements were: platelet (PLT) count >50,000/ml ; prothrombin time (PT), international normalised ratio (INR) <1.3 ; and partial thromboplastin time (PTT) <34 s . The procedure was performed under conscious sedation  and was trained in regular breathing and breath-holding (suspended respiration) before the procedure. He/she was placed in the appropriate position  and a scan of the desired area with a 5-mm slice thickness was performed, using a Picker 5000® .At least one of two staff radiologists with extensive experience in biopsies and tumour ablations was involved in all ablations.The lesion’s exact location and depth, in relation to the overlying skin, was determined on CT. The skin was then prepared with povidone iodine (10%) solution. Local anaesthesia (15 ml of 2% lidocaine hydrochloride solution) was administered.Radiofrequency ablation was performed with a RITA Model 1500® electrosurgical generator  and a seven-array, 2- to 3-cm multitined electrode for lesions smaller than 3 cm (20 out of 34), or a nine-array multitined electrode for larger lesions (14 out of 34). The electrode tip was inserted to approximately 1 cm from the centre of the target. The electrodes were then deployed slowly, taking into account the need to ablate the lesion–bone interface. The net ablation time was ~15 min at an energy level of 90–110 W, with the target goal temperature set to 80–110°C. During the procedure the infusion port of the electrode was flushed with a 2% lidocaine hydrochloride solution in order to reduce patient discomfort and to decrease tissue overheating and vaporisation. The number of electrode placements, individual (per electrode) and total ablation times, the total energy delivered to the target and the lesion temperatures achieved were recorded.After each session a dual-phase spiral CT examination with intravenous contrast medium was performed in order to assess response, as confirmed by low lesion attenuation values and lack of contrast enhancement.Patients were hospitalised and observed for 24 h. Analgesics were administered if required. Before patient discharge the pain was re-evaluated with the BPI score. Post-ablation assessment was completed with telephone interview after one, four and eight week. The BPI score and the use of analgesics were recorded again.For lesions smaller than 3 cm (20 out of 34), one placement was adequate, while for the remaining 14 out of 34 cases of lesions that were larger than 3 cm, two or more placements were required; one lesion sized 14 cm required five placements, accomplished in two sessions (since more deployments are required in larger lesions). The total procedure time ranged between 33 and 65 min . Nineteen of the 30 patients reported early pain reduction. In none of the patients was increased pain reported. Prior to the procedure, the mean past-24-h BPI score for worst pain was 8.3 , mean pain was 6.8, and mean pain interference with daily life 7.5. These scores were reduced to 7.4, 4.7 and 6.5 24 h after the procedure, dropped to 4.9, 3.2 and 4.0 after 1 week, to 3.6, 2.00 and 2.2 after 4 weeks, and to 2.1, 1.4 and 1.7 after 8 weeks respectively. These results revealed a marked decrease in pain with subsequent improvement in the life quality for all participants since the first week post-treatment that lasted throughout the 8-week follow-up , or local deposition of some form of energy . Image-guided RF ablation is currently used for the treatment of various tumours with good results. According to preliminary results by Dupuy et al. , RF ablaThe proposed mechanisms by which RF ablation decreases pain may involve: pain transmission inhibition by destroying sensory nerve fibres in the periosteum and bone cortex; reduction of lesion volume with decreased stimulation of sensory nerve fibres; destruction of tumour cells that are producing nerve-stimulating cytokines  and inhibition of osteoclast activity , 12.In our patients, we observed a considerable reduction of pain and improvement of the quality of life, as measured by the BPI score.A decrease in the use of analgesic medications was notable in our series and possibly greater than others reported in previous studies , 10.The reduction of the procedural time is limited by both the time needed to achieve the optimal target temperature, and the size of the lesion, because more than one deployment is required in larger bone metastases. Although a few patients reported mild discomfort during the ablation, none of the sessions was forced to stop owing to considerable patient distress. There were none of the possible adverse effects, including infection, haemorrhage, neurological complications, skin burns, or the so-called post-ablation syndrome (low-grade fevers ≤100°F [37.8°C]), myalgias, and malaise for up to 1 week after the procedure). Pain reduction was fast and occurred within the first 24 h for some and during the first week in the majority of the patients. This appears to be a fairly well-tolerated procedure and the combination of conscious sedation and local anaesthesia is adequate for its needs.In the spine, RF ablation may be contraindicated due to the close relationship with the spinal cord and nerve root. Vertebroplasty may be used for pain relief and stabilisation of osteolytic lesions. Pain relief occurs within hours or days (mean 24 h) of the procedure, sometimes after a transient worsening of pain . MechaniIn our study, there were no lesions threatening the stability of the spine.There are two conflicting studies in the literature concerning the use of RF ablation in spinal metastases. One of them has demonstrated that the presence of cancellous or cortical bone between the lesion and the spinal canal can provide adequate safety for the procedure , 15. AnoThe follow-up period for this study was 8 weeks, a period that we believed was sufficient to demonstrate that RFA provides effective palliation. There is, however, a need for randomised prospective studies, to evaluate the method and to compare it with other treatment modalities, such as radiation therapy. Continued follow-up is warranted to determine the long-term efficacy of this interventional approach.In conclusion, imaged-guided RF ablation of painful bone metastases is promising. It appears to be effective, safe and well tolerated by patients.


To determine the efficacy and safety of peri-articular hyaluronic acid injections in chronic lateral epicondylosis (tennis elbow).Prospective randomized clinical trial in primary care sport medicine.Three hundred and thirty one consecutive competitive racquette sport athletes with chronic (>3 months) lateral epicondylosis were administered 2 injections (first injection at baseline) into the subcutaneous tissue and muscle 1 cm. from the lateral epicondyle toward the primary point of pain using a two-dimensional fanning technique. A second injection was administered 1 week later.Assessments were done at baseline, days 7, 14, 30, 90 and 356. Efficacy measures included patient's visual analogue scale (VAS) of pain at rest (0-100 mm) and following assessment of grip strength (0-100 mm). Grip strength was determined using a jamar hydraulic hand dynamometer. Other assessments included patients' global assessment of elbow injury , patients' assessment of normal function/activity , patients/physician satisfaction assessment , time to return to pain-free and disability-free sport and adverse events as per WHO definition. Differences between groups were determined using an intent-to-treat ANOVA.Average age of the study population was 49 years (± 12 years). One hundred and sixty-five patients were randomized to the HA and 166 were randomized to the control groups. The change in VAS pain was -6.7 (± 2.0) for HA vs -1.3 (± 1.5) for control (p < 0.001). The VAS post handgrip was -7.8 (± 1.3) vs +0.3 (± 2.0) (p < 0.001) which corresponded to a significant improvement in grip of 2.6 kg in the HA vs control groups (p < 0.01). Statistically significant improvement in patients' global assessment of elbow injury (p < 0.02), patients' assessment of normal function/activity (p < 0.05) and patients/physician satisfaction assessment (p < 0.05) were also observed favoring the HA group. Time to return to pain-free and disability-free sport was 18 (± 11) days in the HA group but was not achieved in the control group. VAS changes were maintained in the HA group at each followup while those in the control significantly declined from baseline. Assessment of patient and physician satisfaction continued to favor the HA group at subsequent followup.Peri-articular HA treatment for tennis elbow was significantly better than control in improving pain at rest and after maximal grip testing. Further, HA treatment was highly satisfactory by patients and physicians and resulted in better return to pain free sport compared to control. Chronic tennis elbow or lateral epicondylosis produces symptoms of pain and functional disability. Typical treatments include RICE for acute exacerbations as well as oral or topical NSAIDs, bracing and physical therapy. However, there is no consensus on treatment while efficacy of existing treatments is poor. Intra-articular hyaluronic acid (HA) has shown efficacy equivalent to NSAID in the treatment of osteoarthritis while it's periarticular efficacy and safety have recently been reported for soft tissue use in acute ankle sprain. Hence, many patients, particularly those who require more rapid improvement to return to sport or work activity, or those in whom previous therapies have not achieved expected results, would benefit from a more rapid alleviation of symptoms, while still achieving the longer term benefits of hyaluronic acid that have been reported in other soft tissue indications.Previous studies regarding treatment of chronic tennis elbow have shown lack of consensus as well as variable efficacy and high incidence of adverse effects . HyaluroTennis elbow , a common cause of chronic elbow pain and wrist extensor dysfunction in adults, affects 1-3% of the general population each year . Tennis There is currently no consensus on the optimum treatment, but numerous options are available. The best available scientific evidence suggests that topical and possibly oral non-steroidal anti-inflammatory drugs may be the most useful for short-term pain relief. Corticosteroid injections may be beneficial as a temporary measure but carry the risk of possible adverse affects ,10. SympHyaluronic acid is a natural occurring biological substance, which has been shown to have a positive effect in inter-articular administration for osteoarthritis  as well Hyaluronic acid is an un-branched, high molecular weight polysaccharide distributed throughout the body, especially as a major component of synovial fluid cartilage and surrounding structures of arthroidial joints. The primary role of the HA in these tissues is to maintain their visco-elastic structural and functional characteristics. Given the long term efficacy and safety of periarticular HA in acute ankle sprain, it would suggest similar protective effects of HA in chronic lateral epicondylosis.We are unaware of any other published studies that have prospectively followed patients who were administered HA in lateral epicondylosis for treatment of tennis elbow in clinical practice.Hence, we hypothesized that HA administered in the soft tissue of lateral epicondylosis for chronic tennis elbow will be well-tolerated with few adverse events and result in improved clinical pain and function outcomes from baseline to long term followup compared to patients administered placebo.We collected data on 331 consecutive patients administered HA  [165 patients] versus 166 patients administered 1.2 cc saline placebo. Treatment course was randomized and consisted of 2 injections (1 at baseline and a second at 7 days). Injections were administered using blinded syringes affixed to a 27-gauge, 1-inch needle. Skin was prepped using betadine 1%. Injections were delivered by the study physician using a standard approach along the lateral epicondyle with the affected arm flexed and resting on a firm surface. Injections were be administered into the soft tissue 1 cm from the lateral epicondyle at the point of greatest pain in two planes using a fanning technique  Follow-up examinations were completed at Day 14 (± 2 days), Day 30 (± 2 days), Day 90 (± 2 days) and at Day 356 (± 7 days). Patients will assess pain on a VAS at rest and after assessment of grip strength. Grip strength will be determined using a jamar hydraulic hand dynamometer . Assessment will be conducted with the patient's elbow fully extended, shoulder in neutral position and the dynamometer's handle in the middle position. Patients will perform three grip tests on the affected arm with a mean score calculated and used for analysis.During the study, including the follow-up period, the patients received usual care including RICE . Use of any analgesics was prohibited and all concomitant medication use was recorded in the patient's diary. Specifically, no NSAID, corticosteroid or topical analgesics were allowed during the study. ASA at the dose of 325 mg and less for cardiovascular prophylaxis was allowed.Patients were assessed for pain on a VAS at rest and after assessment of grip strength. Patients' global assessment of elbow injury , patients' assessment of normal function/activity , and physician's global assessment of elbow injury  was performed. Also, patients/physician satisfaction assessment  and review of a patient diary for adverse events and return to pain and disability-free sport was performed.The primary outcome measures were an improvement on the VAS-pain at rest in the affected elbow and VAS-pain immediately following grip strength testing. Secondary outcome measures included patients' global assessment of elbow injury , patients' assessment of normal function/activity , physician's global assessment of elbow injury , patients/physician satisfaction assessment , time to return to pain and disability-free sport, concomitant medication use and adverse events.The patients were recruited and screened in 4 sites . Patients eligible for the study were 18 or older, with clinically or radiographic diagnosis of tennis elbow, and who were newly referred to the medical outpatient clinics at the author's institution which are primary sport medicine referral centers serving a population of 1.5 million patients. Inclusion criteria were pain at the lateral side of the elbow that had persisted more than 3 months and pain at the lateral epicondyle during resisted dorsiflexion of the wrist with the elbow in full extension. Exclusion criteria were previous local injection treatments (ie. corticosteroid injections or acupuncture), nerve entrapment or systemic neuromuscular disorders.The diagram below provides a description of the overall study design Table .The analyses of the efficacy endpoints used an intent-to-treat (ITT) population. The ITT population was patients who received at least 1 injection of double-blind study therapy. For the efficacy analysis, all patients were counted in the group they were randomized to irrespective of their actual treatment assignment.For the primary analysis of the change from baseline in elbow pain we estimated a sample size of 160 per group using a 40% difference in resting VAS scores at Day 30 between treatment and control, a potential dropout rate of 25% and 95% confidence assuming a standard deviation of <10 mm of the mean deviation, an α of 5%, and a β level of 10%.Both groups (HA = 165 vs placebo = 166) were similar for age (49 ± 15 vs 47 ± 11) and gender  distribution Table . There wMean baseline rest VAS was similar (8.5 ± 1.1 cm and 8.4 ± 1.6 cm) for HA and control respectively. VAS pain at rest and after grip testing was significantly better in the HA vs control Table  at D 30.There is currently no consensus in the management of chronic tennis elbow. Several, reviews have included various therapies targeting local or systemic interventions. Further, these therapies have not shown ability to shorten the disability period nor have they shown long term benefit. In our study, patients who received HA for lateral epicondylosis (tennis elbow) had significantly greater improvement in VAS pain at rest and after grip testing than control that persisted to 356 days followup. The treatment was highly satisfactory to patients and physicians and was associated with very few minor and transient adverse effects. Given the less than optimal treatment options for tennis elbow and given the associated chronic morbidity associated with this condition, periarticular injection with HA may provide an alternative for clinicians and their patients.The authors declare that they have no competing interests.RJP contributed to the study design, data collection, analysis and manuscript preparation.AC contributed to the data collection.JD contributed to the study design, data collection and manuscript preparationNM contributed to the data collection.RL contributed to the data collection.All authors read and approved of the final manuscript.


Twenty patients received transduodenal sphincteroplasty and transampullary septectomy between 1987and 1993. Seven patients had post-cholecystectomy pain which was much improved or abolished in 5 of 7patients at a mean follow-up of 4 years and 5 months. Four of five patients with chronic pancreatitis wereimproved at 3 years and 2 months. Three of five patients with recurrent acute pancreatitis were improvedat 4 years and 5 months. One of three patients with chronic abdominal pain of hepatobiliary origin wasimproved at 3 years. Transduodenal sphincteroplasty and transampullary septectomy can relieve pain inpatients with post-cholecystectomy pain, recurrent acute pancreatitis, chronic pancreatitis, and chronicabdominal pain of hepatobiliary origin, presumably by improving drainage of the obstructed ducts.


The efficacy of selective cox-2 inhibitors in postoperative pain reduction were usually compared with conventional non-selective conventional NSAIDs or other types of medicine. Previous studies also used selective cox-2 inhibitors as single postoperative dose, in continued mode, or in combination with other modalities. The purpose of this study was to compare analgesic efficacy of single preoperative administration of etoricoxib versus celecoxib for post-operative pain relief after arthroscopic anterior cruciate ligament reconstruction.One hundred and two patients diagnosed as anterior cruciate ligament injury were randomized into 3 groups using opaque envelope. Both patients and surgeon were blinded to the allocation. All of the patients were operated by one orthopaedic surgeon under regional anesthesia. Each group was given either etoricoxib 120 mg., celecoxib 400 mg., or placebo 1 hour prior to operative incision. Post-operative pain intensity, time to first dose of analgesic requirement and numbers of analgesic used for pain control and adverse events were recorded periodically to 48 hours after surgery. We analyzed the data according to intention to treat principle.Among 102 patients, 35 were in etoricoxib, 35 in celecoxib and 32 in placebo group. The mean age of the patients was 30 years and most of the injury came from sports injury. There were no significant differences in all demographic characteristics among groups. The etoricoxib group had significantly less pain intensity than the other two groups at recovery room and up to 8 hours period but no significance difference in all other evaluation point, while celecoxib showed no significantly difference from placebo at any time points. The time to first dose of analgesic medication, amount of analgesic used, patient's satisfaction with pain control and incidence of adverse events were also no significantly difference among three groups.Etoricoxib is more effective than celecoxib and placebo for using as preemptive analgesia for acute postoperative pain control in patients underwent arthroscopic anterior cruciate ligament reconstruction.NCT01017380 Multimodal or balanced analgesia, using a combination of analgesics throughout the perioperative period to control postoperative pain, has been increasingly popular and well accepted ,2. NonstThis study was approved by the Ethic Committee of our Faculty. The patients diagnosed as anterior cruciate ligament injury aged between 15 to 50 years old who scheduled for arthroscopic anterior cruciate ligament reconstruction (ACLR) in Songklanagarind hospital during January 2008-January 2009 was included in the study. We excluded the patients who had known allergy, sensitivity or contra-indications to opioids or NSAIDs, having a history of dyspepsia, peptic ulcer or abnormal bleeding, coronary and peripheral arterial diseases as well as allergy to sulfonamide group. The patients who had used NSAIDs, opioids, salicylate within 7 days of the operation were also excluded. The patients were randomized into 3 groups; etoricoxib,celecoxib and placebo using random table containing in the opaque envelope. In etoricoxib group, 120 mg of etoricoxib was orally given. In celecoxib group, 400 mg was given 1 hour before the incision as same as in the controlled group. Both the surgeon and the assessors were blinded to the result of allocation. As a currently common treatment protocol in our country where the hospital cost is inexpensive and for the purpose of direct pain observation, all patients were admitted a night before surgery and discharged at 48 hours post-operatively. The operations were performed under spinal anesthesia using 0.5% hyperbaric bupivacaine without additional intrathecal opioid. The arthroscopic anterior cruciate ligament reconstructions were performed by the principle investigator using autograft bone-patellar tendon-bone. The operative time were recorded. At the end of the operation, all the remaining intra-articular fluid was squeezed out, a vacuum drain was placed intra-articularly and the operative wound was closed before the tourniquet was released. The total drain amount was recorded at 48 hours before removal.All subjects were treated in routine fashion in the recovery room. They were kept until they recovered from the spinal anesthesia and satisfied with recovery room scoring system. The operated knees were locked at in full extension with hinge knee brace for 48 hours and allowed for 0-90 degrees motion at 48 hours when the drain had been removed and wound had been dressing changed. During the post-operative period, the patients were asked to quantify their pain using a Verbal Analog Pain Scale (VbAPS) of 0-100 mm. where 0 represents no pain and 100 mm for unbearable pain. The first pain evaluation was made just before they left the recovery room and then repeated at 4, 8,12, 16, 20, 24, 30, 36, 42 and 48 hours postoperatively. The post-operative pain medications allowed were oral paracetamol 1000 mg taken as needed every 6 hours and/or intravenous fentanyl 1 microgram per kilogram taken every 3 hours as requested by patients. The time to first use of each analgesic medication was recorded. The total amount of both medications was recorded at 48 hours. The patients were also asked to grade their satisfaction with pain control at 48 hours using a Verbal Analog Pain Scale (VbAPS) of 0-100 mm, where 0 represent dissatisfy and 100 mm for most satisfy. The primary outcome of this study was a comparison of the postoperative pain levels in the three groups, while the secondary outcomes were the time to first analgesic analgesics, total amount of analgesics used, the amount of drain output (as represent blood loss) and patients' satisfaction with their pain control. The vital signs were recorded regularly. All adverse drug reactions and side effects were also recorded.The sample size required for this study was 32 patients in each arm. The calculation relied on the primary outcome; post-operative pain intensity, which from previous study found the standard deviations of celecoxib and etoricoxib to be 0.2 and 0.3, respectively. The sample size was based on a 2-sided test with 80% power and a significant level of 0.05. All statistical calculation was performed using STATA version 9.0.We analyzed the data based on intention-to-treat principle. Either chi-square or Fisher's exact test was used to analyze categorical outcomes. Differences among 3 groups of continuous variables were analyzed by analysis of variance (ANOVA). Post-hoc analysis was performed with Bonferroni test.Among 102 patients, 35 were in etoricoxib, 35 in celecoxib and 32 in placebo group. The mean age of the patients was 30 years and most of the injury came from sports injury. There were no significant differences among groups in all demographic characteristics. The duration of injury, associated injuries, concomitant surgeries, mean operative and tourniquet time, and mean drain output were also no differences among groups (Table Postoperative pain following arthroscopic ACL reconstruction could be perceived by the patients immediately in the recovery room as they were recovering from spinal anesthesia, rose to peak intensities around 8 hours and slowly decreased to acceptable level below 40 after 36 hours postoperatively. We found that only etoricoxib, not celecoxib, was effective for use as preemptive analgesia in patients undergoing arthroscopic ACL reconstruction. However, the time to first dose of analgesic medication, total amount of analgesics used, and patient's satisfaction with pain control were also not significantly different among the three groups.Preemptive analgesia is a new strategy of postoperative pain management. The key concept is to prevent the altered sensory processing from surgical process. There are a number of medications being tested for this strategy, including opioids, anesthetic drugs and NSAIDs with conflicting results ,7,21,22.The only head-to-head comparison between etoricoxib and celecoxib was in study of Bingham III, et al.  who compEtoricoxib is more effective than celecoxib and placebo for using as preemptive analgesia for acute postoperative pain control in patients underwent arthroscopic anterior cruciate ligament reconstruction.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2474/11/246/prepub


Today, arthroscopies of the knee joint have become a routine procedure. Generally,these operations are performed under general or spinal anesthesia. In Rheinfelden, localanesthesia is our method of choice. We will summarize our experience with nearly 9000arthroscopies in the last 18 years.        We use 10 mls of ScandicainR as the local anesthetic for the puncture track, followedby an intraarticular injection of 20 mls of CarbostesinR. From 1977 to 1994, arthroscopieswere performed on 8720 patients, of which 90% were outpatients, under localanesthesia. When asked about pain sensation, 50% of patients had no pain at all, 34%expressed mild pain and only 3% reported strong pain. 90% of all patients questionedresponded that they would undergo the same procedure a second time, if necessary.        There are several advantages of local anesthesia, most important the minimal invasiveprocedure. Risk factors can be avoided, the pain level described by the patients is acceptableand the costs are lower than with other anesthetizing techniques. As a prerequisitefor performing these operations under local anesthesia, the surgeon must be very experiencedin the handling and routine of arthroscopic procedures.


Central neuropathic pain is difficult to treat, but delta 9-Tetrahydrocannabinol (delta 9-THC) may be a promising therapeutic agent. We administered in 172 patients on average 7.5 mg delta 9-THC over 7 months. Of these, 48 patients prematurely withdrew due to side effects, insufficient analgesia, or expense of therapy. Thus, 124 patients were assessed retrospectively in a multicenter telephone survey. Reported changes in pain intensity, recorded on a numeric rating scale (NRS), Pain Disability Index (PDI), Medical Outcomes Short-Form (SF-12), Quality of Life Impairment by Pain (QLIP), Hospital Anxiety Depression Scale (HADS), and amount of concomitant pain medication were recorded. Psychometric parameters  and pain intensity improved significantly during delta 9-THC treatment. Opioid doses were reduced and patients perceived THC therapy as effective with tolerable side effects. About 25% of the patients, however, did not tolerate the treatment. Therapy success and tolerance can be assessed by a transient delta 9-THC titration and its maintained administration for several weeks. The present survey demonstrates its ameliorating potential for the treatment of chronic pain in central neuropathy and fibromyalgia. A supplemental delta 9-THC treatment as part of a broader pain management plan therefore may represent a promising coanalgesic therapeutic option. Various drugs belonging to different pharmacologic classes are currently prescribed and administered for the treatment of central neuropathic pain and fibromyalgia syndrome, including antidepressants, first- and second-generation anticonvulsants, antiarrhythmics, topical agents, N-methyl-D-aspartate receptor antagonists, and opioid analgesics , 2. The  Over the last decades, the cannabinoids and their chemistry, the enzymes and receptors involved in their metabolism, as well as their assumed physiological and pathological roles in human pain pathways, have been characterized in detail –8.cannabis sativa, delta 9-Tetrahydrocannabinol (delta 9-THC) is the main active constituent. It is one of the natural compounds of marijuana  and was first synthesized by Mechoulam in 1967 [ Among hundreds of constituents of  in 1967 –14 but t in 1967 . Several in 1967 , 17. Als in 1967 , 19, and in 1967 . The ind in 1967 , as well in 1967 , 22, exp in 1967 , or hype in 1967  are conc in 1967 , 26 rath Here, we explored the clinical applicability and efficacy of delta 9-THC administration supplemental to existing medication plan of patients suffering from refractory central neuropathic pain and fibromyalgia by means of a standardized retrospective telephone interview survey.After approval by the Ethics Committee II, Medical Faculty Mannheim, University of Heidelberg, 19 practitioners within different Federal States of Germany recruited 172 patients diagnosed with central neuropathic pain and fibromyalgia.  The 19 medical specialists were particularly experienced in anaesthesiology, neurology, and algesiology, as well as their extensive experience with the therapy of chronic and neuropathic pain patients. None of the 19 practitioners had received previously industry sponsored research money or were in cooperation with the authors. All practitioners had prescribed THC before and at least 10 times per year and were members of the German Association for Pain Therapy (DGS). Delta 9-THC is available on prescription only. Inclusion criteria for prescription were primarily ineffectiveness of current pain therapy, but also sleep disturbances and decreased quality of life reported by the patients. For titration of the drug, all practitioners increased the oral delta 9-THC dose weekly by 2.5 mg and as long as no severe side effects were reported. Dosing did not exceed 15 mg per day, unless medication was ineffective. Delta 9-THC was taken in the morning and evening and therapy was maintained for at least 3 months. Each medical specialist contributed on average 5–8 patients to the survey, who signed a written informed consent prior to delta 9-THC medication. Only patients with a central neuropathic pain syndrome or fibromyalgia were included, irrespective of gender, age, or ethnic origin. The existence of central neuropathic pain was defined when patients suffered central neuropathy due to an inflammatory damage or trauma of the central nervous system. Exclusion criteria were chronic neuropathic pain states of peripheral origin. All 172 patients received, in addition to their current medication, delta 9-THC  for pain therapy. Demographic data, general health, diagnosis, and medical history were compiled from the patients' files. A researcher, who was experienced in performing telephone interviews, but had no association with the authors or the 19 medical specialists, was employed to collect the data. The interviewer was not informed about the medication plan of the patient or the objective of the survey. Following parameters were recorded: patients' self-reported pain intensity , efficacy and tolerability of the pre-THC regimen, efficacy and tolerability of delta 9-THC medication, improvement in mood and quality of life, general impairment, and work performance. Efficacy and tolerability of pre-THC regimen and current analgesic therapy was recorded using a rating scale in the range from 1 to 6, with the descriptors (1) “very good,” (2) “good,” (3) “satisfying,” (4) “critical,” (5) “insufficient,” and (6) “poorly.” Further, a psychometric assessment was performed, including the Medical Outcomes Short-Form (SF-12), the Pain Disability Index (PDI), the Quality of Life Impairment by Pain (QLIP), and the Hospital Anxiety and Depression Scale (HADS). The perceived pain intensity was estimated by the patients on a 6-point Verbal Rating Scale (VRS) with the particular descriptors : no pain (0), slight pain (2), moderate pain (4), intense pain (6), very strong pain (8), worst pain imaginable (10). In addition, maximum pain intensity was estimated on an 11-point Numeric Rating Scale (NRS) with the endpoints 0 (no pain) and 10 (maximum pain imaginable). Also, patients were requested to evaluate possible changes of symptoms resulting from delta 9-THC treatment. In particular, characteristics of pain intensity and pain quality, tolerability of delta 9-THC therapy, and changes in coanalgesics were recorded. Patients were instructed to specify side effects by means of a list of thirty characters. Recordings made by the patients were documented independently from the practitioner's assessment regarding adverse effects and effectiveness. P-values were calculated for c (columns) × r (rows), StatExact 5.0 software package  was used and Pearson's chi-square test applied (P < .05). Data of psychometric assessment are depicted as mean + standard deviation (SD). Data were analyzed by means of descriptive statistical analysis using SPSS software package . Patients' values prior to delta 9-THC therapy and values during THC treatment were evaluated for significant differences between the values identified by ANOVA. In order to analyze categorical data in which n = 6), insufficient therapy effect (n = 5), expenses of delta 9-THC therapy (n = 29), or other reasons (n = 23) that include mainly dizziness and an enhanced appetite. Consequently, complete data sets were recorded from 124 patients only .Of the 172 patients, 48 prematurely withdrew within 2 weeks from the survey due to tiredness as side effect (n = 114) had been suffering from pain for more than three years, other patients for 1 to 3 years (n = 7). Of 3 patients, however, no duration of pain history could be obtained.Most of the patients (n = 92) was primarily of inflammatory origin (n = 43), such as multiple sclerosis (n = 32), encephalitis (n = 9), and others (n = 2), or due to a trauma of the central nervous system (n = 49), such as stroke (n = 10), paraplegia (n = 8), intracranial injury (n = 4), neoplasm (n = 4), or others (n = 23)  see . A somat In addition to central neuropathy patients, 32 fibromyalgia patients suffering also chronic pain were included in the survey. A controversy is prevailing whether fibromyalgia patients can be included as a central neuropathic pain state. It has been reported in former studies that fibromyalgia is characterized by widespread generalized pain with an abnormal nociceptive central processing , 28. By n = 60 (48%), COX2-inhibitors n = 34 (27%), paracetamol n = 29 (23%), metamizol n = 44 (36%) (see n = 35 (28%), morphine n = 22 (18%), or hydromorphone n = 17 (14%), as well as coanalgesics, such as antidepressants n = 68 (55%) or anticonvulsants n = 40 (32%). Patients most commonly received nonopioids, such as NSAID's 36%) see , but alsn = 1 (0.8%), good n = 4 (3%), satisfactory n = 15 (12%), sufficient n = 24 (19%), insufficient n = 58 (47%), poor n = 20 (16%). The efficacy of the analgesic medication prior to delta 9-THC treatment was assessed by the patients as follows: very good During therapy with delta 9-THC, administration of analgesics could be reduced. Only nonopioids were maintained in 36 patients (29%), opioids continued in 39 patients (31%), and coanalgesic medication pursued in 54 patients (43%) see .n = 78, 63%), as capsule , or both in combination . On average, a mean daily dose below 7.5 mg delta 9-THC was administered to 47 patients (38%), dosages between 7.5 and 15 mg received 26 patients (21%), and dosages >15 mg were taken by 16 patients (13%). In 35 patients (28%) the daily taken delta 9-THC dose could not be obtained. Overall, the median administered delta 9-THC concentration was on average 7.5 mg per day (interquartile range 5–12.5 mg). Delta 9-THC was administered as liquid ( 35 patients received delta 9-THC medication up to 4 months (28%), 38 patients 4–24 months (31%), and 16 patients for more than 24 months (13%). No duration recordings, however, were obtained from 35 patients (28%). Thus, on average, delta 9-THC treatment lasted 217 days (interquartile range 27–412 days).Pain intensity was estimated on a verbal rating scale (VRS), as described previously.n = 2 patients (2%), moderate pain in n = 7 (6%), intense pain in n = 24 (19%), very strong pain in n = 71 (57%), and worst pain imaginable in n = 20 (16%) , revealing a median value of 4 “moderate pain” after delta 9-THC in comparison to a median value of 8 “very strong pain” prior to THC-therapy. In particular, during delta 9-THC administration, no pain was reported on the verbal rating scale in n = 4 patients (3%), slight pain in n = 26 (21%), moderate pain in n = 57 (46%), intense pain in n = 28 (23%), very strong pain in n = 8 (7%), and worst pain imaginable still in 1 patient  see . Followiient see .  Subgroup analysis of fibromyalgia revealed no differences of pain intensity to the group of inflammatory- and trauma-evoked central neuropathic pain patients prior to and during/after delta 9-THC medication. Prior to delta 9-THC administration, mean pain intensity (VRS) of fibromyalgia was on average 7.9 ± 1.5, which was reduced to 4.4 ± 1.5 during/after THC-treatment. Similarly, inflammatory pain patients reported a mean pain intensity of on average 7.6 ± 1.7 before THC, and 4.2 ± 1.9 after delta 9-THC therapy. Trauma-induced central neuropathic pain patients estimated pain at 7.6 ± 1.4 prior to and 3.8 + 1.5 during/after delta 9-THC medication see .n = 4 (3%), NRS 6 in n = 3 (2%), NRS 7 in n = 7 (6%), NRS 8 in n = 17 (14%), NRS 9 in n = 19 (15%), and NRS 10 in n = 74 (60%). In contrast, maximum pain estimated by the patients after delta 9-THC therapy was perceived at NRS <6 in n = 55 patients (44%), NRS 6 in n = 27 (22%), NRS 7 in n = 9 (7%), NRS 8 in n = 23 (19%), NRS 9 in n = 1 (0.8%), and NRS 10 in n = 9 (7%) , as described previously. Pain reported by patients before THC-therapy was NRS <6 in (7%) see . No significant difference of maximum pain was obtained between fibromyalgia syndrome and inflammatory- or trauma-evoked central neuropathic pain patients. On average, maximum pain intensity (NRS) was in fibromyalgia recorded at 9.3 ± 1.1 prior to delta 9-THC and 6.1 ± 2.1 thereafter. Central chronic pain patients reported a maximum pain intensity of 8.7 ± 1.7 (inflammatory pain) and 9.3 + 1 (trauma pain) prior to delta 9-THC, but 4.9 + 2.4 (inflammatory pain) and 5.3 + 1.7 (trauma pain) after THC-therapy, respectively see .P < .001). Similarly, improved Medical Outcomes Short-Form scores (SF-12) were recorded, with significantly increased health-related subscale scores from 23.1 ± 6.3 before therapy to 33.4 ± 9.7 after delta 9-THC administration (P < .001) and a comparable increase of the mental subscale score from 35.6 ± 9.1 to 47.3 ± 7.4 (P < .001), respectively. Quality of life assessed by the pain summary scale (QLIP) also improved by about 150% from 9.7 + 6.6 before therapy to 24.7 + 6.9 after delta 9-THC (see P < .001).Prior to delta 9-THC administration, the Pain Disability Index (PDI) was on average 36.4 ± 10.7, which improved significantly to 22.8 ± 10.8 with the delta 9-THC administration (-THC see . In addi The vast majority of patients (92%) evaluated the delta 9-THC therapy as efficient and accepted its administration as coanalgesic. In contrast, no improvement was reported in 3% of the patients, and 5% complained of increased pain (data not shown).n = 3) and sedation or dizziness (n = 4) were primary side effects.In 12 patients (10%), adverse effects were reported but tolerated during delta 9-THC therapy, of which tiredness (Cannabis (delta 9-THC) has been recognized as appetite stimulant and antiemetic drug, and therefore had been administered clinically to ameliorate side effects in patients receiving, for example, cancer- or HIV-chemotherapy , 34. The In the present retrospective survey we assessed delta 9-THC therapy in central neuropathic pain and fibromyalgia patients. Even though it appears premature to classify fibromyalgia as a neuropathic pain syndrome , these p In our patient sample, THC treatment led to a significant reduction in pain intensity. Noteworthy, this effect could be observed when a mean daily dose of 7.5 mg THC was administered. This dosage shows high acceptance and efficacy. According to our findings, positive reports had been reported previously in smaller patient samples in which delta 9-THC was used for therapy of refractory neuropathic pain states . The aut No effects of delta 9-THC, however, were observed in postoperative pain management  and expeA further important and beneficial effect of delta 9-THC therapy is the change of the patient's mood that can occur in addition to pain reduction. Animal data suggested an antidepressant effect of THC , 44, whi Importantly, in this context, delta 9-THC treatment additionally improved health-related quality of life, as indicated here by the PDI and SF12 scores. Previous data recorded in humans support this finding . ParticuAdministration of delta 9-THC supplemental to the current pain medication did not deteriorate therapy; rather patients were able to reduce the analgesics, particularly the intake of opioids. An interaction between cannabinoids and opioids has been reported in previous experimental studies before and it was suggested that delta 9-THC induced effects are mediated also through delta and kappa opioid receptors . Interes Intriguingly, of the concomitantly administered medication, no change in the use of NMDA antagonists was recorded. This observation might be attributed to a lacking additional effect of cannabinoids with NMDA antagonists. Also, an inhibitory action of selective NMDA antagonists on the antinociceptive efficacy of cannabinoids was reported recently in the rat periaqueductal grey , which msingle telephone survey by one interviewer. A face-to-face serial interviews may be suggested as a better study design alternative, which was considered during development of the study protocol. Performing a multicenter study would require a large number of interviewers conducting the face-to-face interview. The parameter assessment by different interviewers may cause variations, particularly considering psychometric parameters, and irrespective the experiences of the interviewers. A telephone survey, performed by one interviewer only, may be minimally influenced by external factors and therefore suggests consictency of the evaluated parameters in the patient. A limitation of the study is performance of a  Another limitation may be due to the heterogenous patient group with very little selection criteria. This justifiable concern actually was one objective of the survey, that is, to explore the applicability and usefulness of an additional coanalgesic cannabinoid treatment in a broad and unspecific group of pain patients. Consequently, the relatively high drop out rate of about 25% may be due to the virtually absent selection criteria of the patients, but also may have caused by the narrow therapeutic index of THC, as mentioned previously. Amelioration of pain and quality of life improvement were major outcome parameters. In future surveys, therefore, further limiting factors like practice variation, duration of medication, assessment of addiction behaviour, and misuse risk should be considered and included in future interview protocols.Patients taking delta 9-THC for pain therapy can be interviewed easily by phone to explore their tolerance towards the medication. Some but not all patients who respond and tolerate delta 9-THC administration may benefit considerably from this coanalgesic. Acceptance and tolerance of a short-lasting delta 9-THC trial therefore would determine a selection criterion for an additional treatment option to reduce pain, to decrease the comedication, and to improve quality of life. Transient delta 9-THC titration up to about 15 mg, its continued administration for a few weeks, the documentation of the patients tolerance to the therapy with putative side effects, and the recording of the patients' self-reported pain estimates would reveal the efficacy and tolerability of a supplemental cannabinoid-based coanalgesic medication.


Low-back pain is responsible for significant disability and costs in industrialized countries. Only a minority of subjects suffering from low-back pain will develop persistent disability. However, this minority is responsible for the majority of costs and has the poorest health outcomes. The objective of the Clinic on Low-back pain in Interdisciplinary Practice (CLIP) project was to develop a primary care interdisciplinary practice model for the clinical management of low-back pain and the prevention of persistent disability.Using previously published guidelines, systematic reviews and meta-analyses, a clinical management model for low-back pain was developed by the project team. A structured process facilitating discussions on this model among researchers, stakeholders and clinicians was created. The model was revised following these exchanges, without deviating from the evidence.A model consisting of nine elements on clinical management of low-back pain and prevention of persistent disability was developed. The model's two core elements for the prevention of persistent disability are the following: 1) the evaluation of the prognosis at the fourth week of disability, and of key modifiable barriers to return to usual activities if the prognosis is unfavourable; 2) the evaluation of the patient's perceived disability every four weeks, with the evaluation and management of barriers to return to usual activities if perceived disability has not sufficiently improved.A primary care interdisciplinary model aimed at improving quality and continuity of care for patients with low-back pain was developed. The effectiveness, efficiency and applicability of the CLIP model in preventing persistent disability in patients suffering from low-back pain should be assessed. Low-back pain (LBP), e.g. pain in the lumbosacral area of the spine, is one of the most prevalent health problems in industrialized countries, engendering significant disability and costs. Back pain will generally resolve itself in the short term, with only a minority of patients developing persistent disability, disabilSeveral guidelines have been published on the clinical management of LBP, but theThe objective of this project was to develop an interdisciplinary model aimed at the clinical management of adult LBP in primary care, with the aim of preventing persistent disability. The model address the following question: What actions should be taken by primary care providers when an adult presents with LBP in the acute, subacute or persistent stages of the condition, in order to prevent or manage persistent disability? The model was to contribute to better quality and continuity of care for adult patients with LBP.The Clinic on Low-back pain in Interdisciplinary Practice (CLIP) initiative was created and led by a project team (manuscript authors) representing research, academic and clinical experiences: one occupational health physician researcher, two physiotherapist researchers, one occupational therapist researcher, one psychologist researcher, two family physicians, and one physiotherapist clinician. A set of guidelines was chosen by the project team as a base. The Royal College of General Practitioners (RCGP) LBP guidelines publisheNumerous meetings were used by the project team to elaborate the model. During these meetings, project team members brought their findings. Criteria from RCGP guidelines were used to assess the quality of RCTs, with high quality studies having at least 10 patients in each group, and using patient centered validated outcomes (criteria from RCGP guidelines). The OxmAn interdisciplinarity community of practice was created by the project team. They approached 10 key stakeholders from the family physician, physiotherapy and occupational therapy licensing boards and clinician associations. These three groups of professionals provide the vast majority of primary care treatments to workers suffering from LBP in the province. Stakeholders were asked to identify and invite members that would be interested in LBP management. A group of 136 clinicians was assembled and asked to comment the feasibility of the model through online discussion forums and commentary forms. A seven member independent scientific committee, composed of researchers from five universities and of various disciplines , provided comments on the validity of the model. Taking into account comments, the project team decided by consensus if and how the model should be revised, without deviating from the evidence. The final model was summarized in the form of a clinical algorithm.Table Red flags are warning signs that should lead the clinician to investigate for a serious pathology in need of immediate diagnosis (category "C"). These are mainly lumbar complications from a serious trauma or a disease such as cancer. In practice, such complications are rare but systematic questioning and examination is required in order to detect them. NeuroloIn patients suffering from simple low back pain, X-ray, CT scan or MRI results are not associated with the symptoms described by the patient or his perceived disability.A review on the relationship between simple back pain and X-ray results concluded that there is no evidence of a causal relationship between X-ray findings, particularly degenerative changes, and simple back pain. For theWhen patient history and physical examination reveal no red flags, a reliable clinical diagnosis can be made without recourse to medical imaging techniques. When spThe probability of return to work decreases with the length of disability due to low back pain, creating three stages: Acute (less than 4 weeks of disability); subacute (4 to 12 weeks of disability); persistent (more than 12 weeks of disability). The stuThe classification of low back pain into stages permits the identification of the turning points  at which the clinician should adapt the treatment on the basis of a deteriorating prognosis. This adThere is a high level of evidence supporting the influence of certain clinical, psychosocial and work-related factors in the probability of returning to usual activities. In ordeAs mentioned in Principle 1.3, where the likelihood of returning to daily activities is deemed to be low, the clinician should intensify his efforts to identify barriers preventing the return to usual activities. By identifying these barriers, the clinician can adapt treatment or quickly refer the patient to other resources if necessary to avoid chronicity. A revie• Intensity of pain • Perceived disability  of radiating pain below the knee • Fears and beliefs • Patient projection regarding return to work (3-month projection question in the Fear-Avoidance Beliefs Questionnaire)• Catastrophizing • Absence from any type of work (Employment status)Patient perceived disability has been demonstrated in the literature to be related to the barriers influencing the return to usual activities mentioned in Principle 1.4,17. LackA perceived disability questionnaire can be used at four week intervals. The score obtained with this assessment should improve by a certain amount  over a Interest in the importance of the type of information given to patients with low back pain at the first consultation and thereafter is relatively recent. Two corroborating studies on the subject have shown that essential, coherent and accessible information can have a positive impact on the patient's recovery ,30. EsseInformation given to the patient with low back pain is important because it allows the patient to understand what is at stake therapeutically and become involved in his functional recovery. However, information can be a double-edged sword since contradictory or poor quality information can work against the patient's wellbeing and slow down the return to usual activities. Regardi• Reassure the patient about the generally positive prognosis of back pain;• Reassure the patient that serious spinal problems are rare and that the signs (red flags) for such problems are not present;• Reassure the patient regarding returning to or continuing usual activities, including work, even in the presence of symptoms;• Avoid labelling the patient by putting an exaggerated emphasis on a specific spinal problem and its impact.Evidence supported by high quality studies show the superior advantage of encouraging activity to prescribing bed rest. AlthougThe patient advised to continue or to resume daily activities including work and to avoid bed rest as much as possible recovers more quickly than the patient who is advised to be guided by pain in resuming activity. AlthougNumerous therapeutic interventions have been proposed for the treatment of low back pain. In recent years considerable research has been devoted to the rigorous evaluation of the most common therapeutic interventions. The syntheses of these Cochrane type studies or the most up to date meta-analyses were compiled to create tables • Strong: consistent findings in several high quality studies;• Moderate: consistent findings in lesser quality studies, particularly with small numbers of subjects;• Poor: Based on the results of only one study or inconsistent findings in several studies• Lack of evidence: Based on studies with no comparison group, on theoretical considerations or on expert consensus.Each of the modalities is qualified as "recommendable", "not recommendable" or "unknown efficacy". Because the design of the tables requires some interpretation of the source documents, it is necessary to refer directly to them to understand the meaning and impact of these recommendations. Clinical application methods can vary considerably among the studies and the meaning of the conclusions can differ according to clinical context.In addition, there are many treatments for which no studies exist and no recommendation can be made. Further studies are necessary before it is possible to rate their efficacy. The lack of scientific evidence does not in itself discredit a treatmentAs mentioned in Principle 1.3, the possibility of returning to usual activities diminishes significantly with the approach of persistent low back pain. In addition, the risk of persisting symptoms is greater. Evidence related to the treatment of sub-acute and persistent low back pain is concerned primarily with communication and the multidimensional nature of the barriers preventing the return to usual activities. With reWhen the patient does not return to all or some activity after 12 weeks of back pain, the possibility of returning to usual activities decreases significantly and the risk of persisting symptoms increases. The litCare should be oriented towards the identification and management of individual and environmental barriers preventing the return to usual activities (see Principle 1.4) and on decreasing symptom-based treatment. This change can be done by encouraging patient participation in his management of low back pain and by involving the stakeholders who can contribute to diminishing the barriers.Once persistent disability is present, the multiplicity and entrenchment of individual and environmental barriers results in a handicap that keeps the individual from returning to usual activities. A review identified most of the barriers that limit the return to usual activities, including work, in the presence of persistent low back pain. They reAlthough standardized tools to assess the extent of barriers to return to usual activities are proposed, precise interventions to manage these barriers are not available in the literature. It is not known if these barriers are modifiable by a clinician, or how they should be managed. Also, it is not known if managing these barriers can actually prevent persistent disability. This reflects the current relative lack of knowledge in the literature in this area needing further research.When the clinician feels that help is needed to facilitate the return to usual activities for a patient suffering from persistent low back pain, he can refer the patient to specialized resources available in his area. The primary care clinician remains a resource for the patient throughout the rehabilitation process and during subsequent low back pain episodes.Figures This process had the objective of developing a primary care interdisciplinary model aimed at preventing persistent disability related to LBP. The CLIP model was designed for family physicians, physiotherapists and occupational therapists, irrespective of their specific expertise. It's goal was to promote the use of similar tools and common language in the management of LBP from a bio-psycho-social perspective. The model promoted common therapeutic goals in terms of returning the patients to their usual activities, periodic evaluation of perceived disability and re-orientation of care when limited results are achieved. The shift of focus from specific therapeutic interventions to process of care has two important implications for clinical practice: 1) evaluate the patient's perceived disability with a validated instrument; 2) identify barriers to return to activity and to orient the patient's management accordingly. The CLIP model can be used in interdisciplinary training sessions, with several types of health professionals present at the same time.This model was developed through a rigorous process of literature search and synthesis, and interdisciplinary exchanges among researchers and health professionals. The interpretation of the evidence on the efficacy of therapeutic interventions provided in the summary tables was consistent with previously published guidelines,23. HoweThis model does not take into account the time, resources and costs needed to use it. Resistance in use should be expected, since this model requires a shift from a pathophysiological to a biopsychosocial model of disease management. Difficulties in using such evidence have been previously demonstrated -49. In oA model for the clinical management of low-back pain and prevention of persistent disability was developed. The following five elements were elaborated for the evaluation of LBP: 1) In order to detect serious problems requiring immediate or specialized treatment, the clinical examination should triage patients according to the three types of low back pain: non-specific, with neurological involvement, with serious pathology (red flags); 2) Radiographic, MRI or CT scan examinations are rarely indicated for patients with non-specific back pain; 3) The clinician should assess the patient's perceived disability and the probability of a return to usual activities, either in the fourth week if back pain related disability persists, or at the first consultation if the patient has a history of long lasting disability due to back pain; 4) When the probability of returning to usual activities is deemed to be low, the clinician should seek to identify the barriers preventing the return to usual activities; 5) If the patient's perceived disability improves little or not at all in the 4 weeks following assessment of this perception, the clinician should reassess the barriers preventing the return to usual activities and revise management. The following four elements were elaborated for the management of LBP: 1) Reassure the patient with back pain by providing essential, coherent, accessible and valid information about his condition and correcting beliefs; 2) The clinician should encourage and guide the patient to continue or to resume usual activities; 3) The clinician should give priority to treatments of proven efficacy; 4) When individual or environmental barriers to the return to usual activities are identified after the acute phase of low back pain, the clinician should reorient treatment towards minimizing those barriers.The authors declares that they have no competing interests.All authors participated in conception and design of the study, acquisition of data, interpretation of data, and revision of the manuscript. All authors read and approved the final manuscript. SP and MR additionally analyzed the data and drafted the manuscript.The pre-publication history for this paper can be accessed here: