Comparative study between computer assisted-navigation and conventional technique in minimally invasive surgery total knee arthroplasty, prospective control study. [Clinical outcome following robotic assisted versus conventional total hip arthroplasty: a controlled and prospective study of seventy-one patients]. Comparison of gait in patients following a computer-navigated minimally invasive anterior approach and a conventional posterolateral approach for total hip arthroplasty: a randomized controlled trial. Comparison between computer-assisted-navigation and conventional total knee arthroplasties in patients undergoing simultaneous bilateral procedures: a randomized clinical trial. Comparison of Outcome and Survival After Unicompartmental Knee Arthroplasty Between Navigation and Conventional Techniques With an Average 9-Year Follow-Up. A randomized, prospective study of 3 minimally invasive surgical approaches in total hip arthroplasty: comprehensive gait analysis. Total hip arthroplasty surgical approach does not alter postoperative gait mechanics one year after surgery. Robot-assisted Total Knee Arthroplasty What do we get from navigation in primary THA? Navigation of total knee arthroplasty: rotation of components and clinical results in a prospectively randomized study Computer navigation vs conventional total knee arthroplasty: five-year functional results of a prospective randomized trial. Minimally invasive compared with traditional transgluteal approach for total hip arthroplasty: a comparative gait analysis. Limitations of imageless computer-assisted navigation for total hip arthroplasty. Objective functional assessment of total hip arthroplasty following two common surgical approaches: The posterior and direct lateral approaches Mini-incision technique for total hip arthroplasty with navigation. Image Guided Navigation System to Measure Intraoperatively Acetabular Implant Alignment Robot‐assisted total hip arthroplasty: Clinical outcomes and complication rate
BACKGROUND Both Minimally Invasive surgery ( MIS ) and Computer-Assisted Surgery ( CAS ) are useful in Total Knee Arthroplasty ( TKA ) . Minimally invasive total knee arthroplasty was associated with decreased blood loss , shorter hospital stays , and increased range of motion .  Computer-assisted surgery in total knee arthroplasty was developed to improve the positioning of implants during surgery . OBJECTIVE To evaluate radiographic results relative to component position and limb alignment when using a navigation system compared with conventional technique in MIS-TKA . MATERIAL AND METHOD A prospect i ve control study was performed in 180 patients who underwent total knee arthroplasty by one surgeon . All patients were r and omly divided into two groups , Conventional and Navigation TKA .  Intra- , post-operative data , and postoperative limb alignment were recorded for comparison in both groups . RESULTS The postoperative mechanical axis was within 3 degrees of neutral mechanical alignment in 94 % of the navigation group and 87 % in conventional group ( p = 0.13 ) . Registration time of navigation group is 13.58 minutes . No statistical significant difference was found in tourniquet time and postoperative blood loss in both groups . CONCLUSION The use of navigation in total knee arthroplasty increases accuracy in limb and implants alignment , and does not increase complications and surgical times AIM Robotic assisted total hip arthroplasty  remains controversial , since wider exposure of the proximal femur and placement of the leg in maximal hip adduction and external rotation using a rigid leg-holder apparatus may impair significantly the hip abductors . Consequently , it is the purpose of this study to analyse and report both clinical outcome and hip abductor function following robotic assisted versus conventional total hip arthroplasty . MATERIAL AND METHODS 36 robotic-assisted ( CASPAR , Orto-Maquet , Rastatt , Germany ) and 35 conventional cementless total hip arthroplasties  were followed on average for 18 months regarding incidence of complications , Harris hip score , the scoring system according to Merle d'Aubigné and Postel , hip abductor function ( using a spring-balance ) , and incidence of Trendelenburg 's sign ( according to the Kuhfuss-classification ) . Statistical analysis was performed in case of continuous data using the t test and the Mann-Whitney test , respectively , and in case of categorical data using Fisher 's exact test and the chi-squared test , respectively . The level of significance was set as p < 0.05 . RESULTS Average duration of surgery ( CASPAR : 100.6 min ; conventional : 51.5 min ; p < 0.0001 ) as well as average loss of haemoglobin ( CASPAR : 4.5 mg/dL ; conventional : 3.3 mg/dL ; p = 0.0002 ) differed significantly , whereas the incidence of complications ( CASPAR : two dislocations , one sciatic paresis , one deep infection ; conventional : one dislocation , two fissures ) , revision rate ( CASPAR : 5.6 % ; conventional : 2.9 % ) , and incidence of heterotopic ossifications ( CASPAR : 30.6 % ; conventional : 17.1 % ) was comparable following both procedures ( p > 0.05 ) . Improvement of the Harris hip score also was comparable in both groups ( CASPAR : 40.9 to 86.1 points ; conventional : 39.5 to 88.0 points ; p = 0.21 ) , whereas improvement of the score according to Merle d'Aubigné and Postel was significantly greater following the manual procedure ( CASPAR : 10.1 to 16.0 points ; conventional : 8.3 to 16.6 points ; p < 0.0001 ) . Differences between the two groups were also significant regarding hip abductor function ( CASPAR : 76.1 % ; conventional : 93.8 % of the contralateral hip ; p < 0.0001 ) and incidence of Trendelenburg 's sign ( CASPAR : 61.1 % ; conventional : 25.7 % ; p = 0.0014 ) . CONCLUSION The significant functional impairment following robotic assisted THA should be taken critically into consideration prior to initiating such procedure Minimally invasive total hip arthroplasty ( MIS THA ) aims at minimizing damage to muscles and tendons to accelerate postoperative recovery . Computer navigation allows a precise prosthesis alignment without complete visualization of the bony l and marks during MIS THA . A r and omized controlled trial ( RCT ) was conducted to determine the effectiveness of a computer-navigated MIS anterior approach for THA compared to a conventional posterolateral THA technique on the restoration of physical functioning during recovery following surgery . Thirty-five patients underwent computer-navigated MIS THA via the anterior approach , and 40 patients underwent conventional THA using the conventional posterolateral approach .  Gait analysis was performed preoperatively , 6 weeks , and 3 and 6 months postoperatively using a body-fixed-sensor based gait analysis system . Walking speed , step length , cadence , and frontal plane angular movements of the pelvis and thorax were assessed . The same data were obtained from 30 healthy subjects . No differences were found in the recovery of spatiotemporal parameters or in angular movements of the pelvis and thorax following the computer-navigated MIS anterior approach or the conventional posterolateral approach . Although gait improved after surgery , small differences in several spatiotemporal parameters and angular movements of the trunk remained at 6 months postoperatively between both patient groups and healthy subjects BACKGROUND Total knee arthroplasty has been increasingly used for young and active patients , and prosthesis durability is important in these patients . The accuracy of implant placement has been one of the major factors that determine the long-term survival of the prosthesis . The purpose of this study was to compare the accuracy of prosthetic alignment between computer-assisted-navigation and conventional total knee arthroplasties . METHODS From March 2007 to June 2008 , thirty-two patients with bilateral knee osteoarthritis underwent simultaneous bilateral total knee arthroplasty with the same type of implant in each knee .  The subjects included seven men and twenty-five women , with an average age of sixty-three years . For each patient , the bilateral total knee arthroplasty was performed with computer-assisted navigation in one knee and a conventional technique in the other . The operative technique and the order of the surgical procedures were r and omized . The patients and surgeons conducting the follow-up study and performing the imaging measurements were blinded to the type of surgical procedure . RESULTS There was a significant difference between the two groups with regard to the alignment of the knee prosthesis in the coronal and sagittal planes . Nine knee implants ( 28 % ) in the conventional group , compared with no knee implants in the computer-navigation group , deviated > 3 ° from the mechanical axis in the coronal plane . The coefficient variation of data in the conventional group was three times greater than that in the computer-navigation group . There was no significant difference in the rotational angle of the femoral component between the two groups . The Hospital for Special Surgery ( HSS ) scores at six months postoperatively were substantially increased compared with the preoperative scores in both groups . CONCLUSIONS Computer-assisted navigation consistently provided coronal plane alignment within 3 ° of the mechanical axis , which was significantly better than the alignment obtained with conventional total knee arthroplasty BACKGROUND Unicompartmental knee arthroplasty(UKA ) has become a treatment of choice for many patients with isolated unicomparmental arthritis due to its specific advantages over total knee arthroplasty , but few studies have compared conventional and navigational UKA with similar instrumentation on mid- to long-term results . We investigated whether the use of imageless navigation can improve implant positioning and clinical outcomes of UKA at a long-term follow-up compared to the conventional technique . METHODS We prospect ively studied clinical and radiological results in 68 patients with an average age of 64.0 years ( range , 50 to 81 years ) who received UKA between January 2003 and December 2005 using the conventional or navigational technique .  Clinical evaluations were performed preoperatively and the last follow-up included knee range of motion , Hospital for Special Surgery ( HSS ) scores , Western Ontario and McMaster Universities Osteoarthritis Index ( WOMAC ) scores and Visual Analogue Scale ( VAS ) pain score . For radiologic evaluation , the mechanical alignment of the lower limb was measured using mechanical femoro-tibial angle ( mFTA ) and Kennedy protocol . RESULTS After an average 9-year follow-up ( range , 7.4 to 10.8 years ) , the navigation group showed better coronal alignments of the components , fewer radiological outliers and better clinical scores , but similar estimated 10-year prosthesis survival rates . CONCLUSION This study indicates that the use of navigation significantly contributes to the desired mechanical axis and improved component placement as compared to the conventional technique . LEVEL OF EVIDENCE Prospect i ve comparative study , Level III Purported advantages of total hip arthroplasty performed with minimally invasive surgical ( MIS ) approaches are less muscle damage and faster recovery . There are little data scientifically evaluating these cl aims . Twenty-four consecutive hips were r and omized to total hip arthroplasty through 1 of 3 MIS approaches ( 2-incision , mini-posterior , and mini-anterolateral ) . Each patient underwent preoperative and postoperative gait analysis . Gait parameters included vertical ground reaction force , velocity , single-leg stance time , limb-loading rate , and abductor torque . All 3 groups demonstrated overall improvements in gait parameters at 6 weeks postoperatively . The anterolateral approach patients showed a decrease in the vertical ground reaction force at mid-stance , whereas the 2-incision and posterior approaches demonstrated no significant change . These results fail to demonstrate any significant advantage of the 2-incision approach over the posterior approach in kinetic gait parameters . Furthermore , the anterolateral approach demonstrates a gait pattern consistent with abductor muscle injury in the early recovery period , despite the MIS approach OBJECTIVE To investigate the differences in gait biomechanics on the basis of surgical approach 1 year after surgery .  DESIGN This was a descriptive laboratory study to investigate the side-to-side differences in walking mechanics at a self-selected walking speed as well as a functional assessment 1 year after total hip arthroplasty ( THA ) .  Temporospatial , kinetic , and kinematic data as well as functional outcomes were collected . Two-way analysis of variance was used to assess for between-group differences and limb-to-limb asymmetries . SETTING A controlled laboratory study . PARTICIPANTS This study examined 35 patients with primary , unilateral THA . The THA surgical approaches that were used in these patients included 12 direct lateral , 18 posterior , and 11 anterolateral . All the patients were assessed 1 year after THA . Patients were excluded from the study if they had contralateral hip pain or pathology , or any prior lower extremity total joint replacements . MAIN OUTCOME MEASUREMENTS Three-dimensional lower extremity kinematics and kinetics as well as spatiotemporal variables were collected . In addition , a series of physical performance measures were collected . RESULTS No main effects for the physical performance measures or biomechanical variables were observed among the approach groups . Significant limb-to-limb asymmetries were observed among all the patients , with decreased sagittal plane range of motion , peak extension , and peak vertical ground reaction forces on the operative side . CONCLUSION The results of this study indicated that no significant differences existed among the different surgical approach groups for any study variable . However , 1 year after THA , the patients demonstrated asymmetric gait patterns regardless of surgical approach , which indicated the potential need for continued intervention through physical therapy to regain normal side-to-side symmetry after THA Increasing evidence suggests performing  total knee arthroplasty  using computer navigation can lead to more accurate surgical positioning of the components and knee alignment compared to a conventional operating technique without computer assistance . The use of robotic technology could theoretically take this accuracy one level further because it uses navigation in combination with ultimate mechanical precision , which could eliminate or reduce the inevitable margin of error during mechanical preparation of the bony cuts of total knee arthroplasty by the surgeon . We prospect ively followed 25 consecutive cases using an active surgical robot . The minimum followup was 5.1 years ( mean , 5.5 years ; range , 5.1 - 5.8 years ) . Our results demonstrate excellent implant positioning and alignment was achieved within the 1 ° error of neutral alignment in all three planes in all cases . Despite this technical precision , the excessive operating time required for the robotic implantation , the technical complexity of the system , and the extremely high operational costs have led us to ab and on this procedure and direct our interest more toward smart semiactive robotic systems . Level of Evidence : Level IV , therapeutic study . See the Guidelines for Authors for a complete description of levels of evidence Navigation in primary total hip arthroplasty has a history of over 20 years . During this process , imageless computer navigation can be particularly helpful in optimally restoring the hip ’s biomechanics . This involves the accurate placement of the acetabular component with the determination of the anteversion and abduction , whereby the navigated femur-first technique also allows for a calculation of the combined anteversion . Additional critical parameters such as the reconstruction of the rotation centre , as well as the femoral and acetabular offset , can also be optimally adjusted . Last but not least , an intra-operative evaluation and equalisation of the leg length is possible . Nonetheless , the disadvantages of this surgical technique in terms of the high costs in the acquisition and preservation of the necessary devices , as well as the longer operation time , must be taken into account . However , economic aspects are not the only thing preventing widespread use of the navigation technique . Determining the plane of reference ( APP ) for the optimal orientation of the implants is based on palpation of the bony l and marks – and this is influenced by the thickness of the soft tissue layer . Furthermore , the experience of the surgeon constitutes a variable that influences the accuracy of navigation . In summary , hip navigation certainly offers an interesting technique for the optimisation of  total hip arthroplasty with reconstruction of proper biomechanics . At the same time , there is currently a lack of high- quality r and omised controlled long-term trials that evaluate the clinical advantage for the patients , together with cost utility and survival rates . Cite this article : Renner L , Janz V , Perka C , Wassilew GI . What do we get from navigation in primary THA ? EFORT Open Rev 2016;1:205 - 210 . 10.1302/2058 - 5241.1.000034 Background Navigation was introduced into  total knee arthroplasty ( TKA ) to improve accuracy of component position , function and survival of implants . This study was design ed to assess the outcome of navigated TKA in comparison with conventional implantation with the focus on rotational component position and clinical mid-term results . Methods In a prospect ively r and omized single-blinded approach , 90 patients with primary gonarthrosis were assigned to three different groups . Thirty patients each were assigned to NexGen LPS without and with navigation ( groups 1 and 2 ) , and 30 patients to navigation with the Stryker Scorpio PS ( group 3 ) . The navigation system used was the imageless Stryker KneeTrac , version 1.0 . Clinical outcome was assessed by a blinded observer applying the Knee Society Score ( KSS ) and a visual analogue scale ( VAS ) for pain . CT scans and radiographs were conducted prior to and 12 weeks after index surgery . Results Seventy-nine patients were available for clinical evaluation at 3 ± 0.4 years follow-up . Four implants had to be revised for early loosening or infection ( 4.4 % ) . Four patients had died and three patients were not able to follow the invitation for clinical assessment . Functional results in the KSS were significantly lower after navigated TKA . Operation time and incisions with navigation were significantly longer . Significantly less radiological outliers with navigation were found for coronal alignment of the femur , only . Conclusion In this series , no beneficial effect for navigation in TKA could be shown assessing clinical data , as functional results in the presented series seemed to be lower after first generation navigated TKA . The clinical mid- to long-term value of navigation remains to be evaluated in larger patient series or meta-analyses at longer follow-up . Trial registration numberDRKS Seventy-one patients were r and omly allocated to undergo either computer-navigated or conventional arthroplasty . A statistically significant improvement in alignment was seen in the computer-navigated cohort . Five-year functional outcome was assessed using the Knee Society , Short Form-36 , Western Ontario and McMaster Universities Osteoarthritis Index , and a patient satisfaction score . At 5 years , 46 patients were available for assessment ( 24 navigated and 22 conventional knees ) . No patients had undergone revision . No statistically significant difference was seen in any component of any measure of outcome between navigated and conventional cohorts . Longitudinal data showed function to be well maintained with no difference in functional score between 2 and 5 years in either cohort . Despite achieving better alignment , 5 years postoperatively , the functional outcome with computer-navigated knee arthroplasty appears to be no different to that implanted using a conventional jig-based technique BACKGROUND Minimally invasive total hip arthroplasty is purported to allow an improved and faster rehabilitation in the immediate postoperative period because of reduced soft-tissue damage compared with total hip arthroplasty performed with use of a st and ard approach . In the present study , a minimally invasive approach was compared with a traditional st and ard approach in terms of the effect on gait kinematics as demonstrated with gait analysis and electromyography . METHODS Twenty r and omized patients who underwent a primary total hip replacement with use of a minimally invasive modified Watson-Jones approach ( minimally invasive group ) were compared with a group of twenty patients who underwent a total hip arthroplasty with use of a st and ard transgluteal Hardinge approach ( st and ard group ) . All patients received the same cementless implant , inserted with use of st and ard instruments , and all operations were performed by a single , experienced surgeon . The patients were evaluated with use of three-dimensional gait analysis and dynamic electromyograms at three time points : preoperatively , ten days postoperatively , and twelve weeks postoperatively . Temporospatial and joint-kinematic parameters were evaluated . RESULTS There were no significant differences between the two groups with regard to the temporospatial variables of velocity , cadence , step length , and stride length at any tested time point . With regard to the range of motion of the operatively treated hip , the minimally invasive group had a smaller decrease at the ten-day time point in comparison with the st and ard group . However , this finding was not significant . The reduction in the range of motion was mainly caused by reduced hip extension . A compensatory increase in the pelvic tilt was observed in both groups . One patient in the st and ard group showed a positive Trendelenburg gait ten days postoperatively ; it had disappeared completely at the twelve-week time point . CONCLUSIONS With regard to gait kinematics in the early postoperative period ( three months ) , the present study showed no significant benefit for patients who underwent a total hip arthroplasty through a minimally invasive Watson-Jones approach in comparison with those who were managed with a st and ard transgluteal approach We prospect ively evaluated acetabular cup placement in total hip arthroplasty with an imageless computer navigation system  or using conventional manual technique . The achieved cup orientation in the manual group had substantially larger variances and greater placement error than the navigation cases . The use of navigation was ab and oned in 3 cases because of excessive pelvic tilt and unreliable registration of the pelvis . Computer navigation system helped improve the accuracy of the acetabular cup placement for total hip arthroplasty in this study . The variation between the intraoperative navigation readings and the computed tomographic values suggests that relying on palpation of bony l and marks through drapes and tissue is a limitation of this method . Further , the variation in pelvic tilt has an effect on cup placement that requires further studies Abstract Despite the high number of total hip arthroplasty ( THA )  procedures performed each year , there is no common consensus on the best surgical approach . Gait is known to improve following THA although it does not return to what is typically quantified as normal , and surgical approach is believed to be a contributing factor . The current study evaluates post-operative hip function  and provides an objective assessment following two common surgical approaches : the McFarl and —Osborne direct lateral and the southern posterior .  Faced with the common problem of providing an objective comparison from the wealth of data collected using motion analysis techniques , the current study investigates the application of an objective classification tool to provide information on the effectiveness of each surgery and to differentiate between the characteristics of hip function following the two approaches . Seven inputs for the classifier were determined through statistical analysis of the biomechanical data . The posterior approach group exhibited greater characteristics of non-pathological gait and displayed a greater range of functional ability as compared with the lateral approach cohort . The classification tool has proved to be successful in characterizing non-pathological and THA function but was insufficient in distinguishing between the two surgical cohorts This prospect i ve study compares a mini-incision technique and traditional posterior approach for total hip arthroplasty ( THA ) . Thirty-three patients who had undergone a mini-incision THA were matched by diagnosis , gender , average age , and preoperative Harris Hip Score ( HHS ) to 33 patients who had undergone THA using the traditional posterior approach .  The average length of the incision for group 1 was 11.7 cm ( range , 7.3 - 13.0 ) and for group 2 was 20.2 cm ( range , 14.8 - 26.0 ) . At the 3-month follow-up , patients in the mini-incision group had significant improvement in limp ( P<.05 ) and ability to climb stairs ( P < .01 ) compared with the traditional group . At the 6 month follow-up , the mini-incision group was significantly better in terms of limp ( P < .05 ) , distance walked ( P<.001 ) , and stairs ( P < 0.001 ) . There was no significant difference between groups for pain , function , or range of motion at the 1-year follow-up examination There has been little clinical research to examine the effects of patient positioning and pelvic motion on the alignment of the acetabular implant during total hip replacement surgery . Until now , no tools were capable of accurately measuring these variables during the actual procedure . As part of a broader program in medical robotics and computer assisted surgery , a clinical system has been developed that includes several enabling technologies . The hip navigation system ( HipNav ) continuously and precisely measures pelvic location and tracks relative implant alignment intraoperatively . HipNav technology is used to gauge current clinical practice and provide intraoperative feedback to surgeons with the goal of improving the precision and accuracy of acetabular alignment during total hip replacement . This system provides surgeons with a new class of image guided measurement tools and assist devices . These tools successfully were introduced into the clinical practice of surgery with results showing the following : ( 1 ) There exist unpredictable and large variations in the initial position of patients ' pelves on the operating room table and significant pelvic movement during surgery and during intraoperative range of motion testing ; ( 2 ) current mechanical acetabular alignment guides do not account for these variations , and result in variable and in the majority of cases unacceptable acetabular alignment ; and ( 3 ) press fitting oversized acetabular components influences the final cup orientation BACKGROUND The purpose of this study was to report minimum 2-year outcomes and complications for robotic-arm-assisted total hip arthroplasty ( THA )  . METHODS Data were prospect ively collected and retrospectively review ed between June 2011 and April 2014 . Inclusion criteria were primary robotic-arm-assisted THAs treating idiopathic osteoarthritis with ≥ 2-year follow-up .  Demographics , operating time , complications , 2-year outcome scores and satisfaction , and subsequent surgeries were recorded . RESULTS There were 181 cases eligible for inclusion , of which 162 ( 89.5 % ) had minimum 2-year follow-up . At the latest follow-up , the mean visual analogue scale was 0.7 , satisfaction was 9.3 , Harris hip score was 91.1 and forgotten joint score was 83.1 . Six ( 3.7 % ) intraoperative complications and six ( 3.7 % ) postoperative complications were reported . No leg length discrepancies ( LLDs ) or dislocations were reported . CONCLUSIONS Robotic-arm-assisted THA demonstrates favourable short-term outcomes and does not result in a higher complication rate compared to non-robotic THA as reported by the literature
Results Significant differences were found in the femoral offset and overall complication rate between the conventional and navigation groups .
Additionally , the conventional group had significantly less anteversion than the navigation group .
However , the navigation group had significantly better inclination .
The operation time was significantly shorter in the conventional than navigation group .
Conclusion Both the OrthoPilot navigation system and conventional total hip arthroplasty result in significant improvements in patient function with similar overall complication rates and have their own advantages in achieving good cup position .
The conventional procedure has a shorter operation time than does use of a navigation system
Objective This study was performed to compare the clinical efficacy between the OrthoPilot navigation system and conventional manual surgery in patients undergoing total hip arthroplasty .