Limitations of imageless computer-assisted navigation for total hip arthroplasty. Comparative Study on Anterior Cruciate Ligament Reconstruction: Determination of Isometric Points with and Without Navigation 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. Impingement-free range of movement, acetabular component cover and early clinical results comparing 'femur-first' navigation and 'conventional' minimally invasive total hip arthroplasty: a randomised controlled trial. Outcomes after conventional versus computer-navigated anterior cruciate ligament reconstruction. Leg axis after computer-navigated total knee arthroplasty: a prospective randomized trial comparing computer-navigated and manual implantation. Comparative study between computer assisted-navigation and conventional technique in minimally invasive surgery total knee arthroplasty, prospective control study. Navigated and nonnavigated total hip arthroplasty: results of two consecutive series using a cementless straight hip stem.
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 OBJECTIVES : To compare the accuracy of  tunnel placement  and graft isometry for anterior cruciate ligament reconstruction performed using a computer-assisted navigation system ( Orthopilot ) and using traditional instruments . METHODS : The anterior cruciate ligament was removed intact from 36 pairs of human cadaver knees . From each pair , one knee was r and omized to Group 1 ( conventional ) and the other to Group 2 ( Orthopilot ) . An inelastic suture was then passed through the central points of the tibial and femoral tunnels . Neither of the tunnels was drilled . All knees were then dissected , and six parameters were obtained : distances from the tibial tunnel center to the 1 ) posterior cruciate ligament , 2 ) anterior horn of the lateral meniscus and 3 ) medial tibial spine ; 4 ) distance from the femoral tunnel center to the posterior femoral cortex ; 5 ) femoral tunnel coronal angle ; and 6 ) variation of the distance from the femoral to the tibial tunnel with the knee extended and at 90 degrees of flexion . RESULTS : The variation of the distance from the femoral to the tibial tunnel during flexion and extension was smaller in the Orthopilot group ( better isometry ) compared to the conventional group . There were no statistical differences in any other parameters between the groups , and all tunnels were considered to be in satisfactory positions . DISCUSSION : The results obtained for anterior cruciate ligament reconstruction depend on precise isometric point positioning , and a navigation system is a precision tool that can assist surgeons in tunnel positioning . CONCLUSION : No differences in tunnel position were observed between the groups . Nonetheless , better isometry was achieved in the Orthopilot group than with conventional instruments 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 We report the kinematic and early clinical results of a patient- and observer-blinded r and omised controlled trial in which CT scans were used to compare potential impingement-free range of movement ( ROM ) and acetabular component cover between patients treated with either the navigated ' femur-first ' total hip arthroplasty ( THA ) method ( n = 66 ; male/female 29/37 , mean age 62.5 years ; 50 to 74 ) or conventional THA ( n = 69 ; male/female 35/34 , mean age 62.9 years ; 50 to 75 ) . The Hip Osteoarthritis Outcome Score , the Harris hip score , the Euro-Qol-5D and the Mancuso THA patient expectations score were assessed at six weeks , six months and one year after surgery . A total of 48 of the patients ( 84 % ) in the navigated ' femur-first ' group and 43 ( 65 % ) in the conventional group reached all the desirable potential ROM boundaries without prosthetic impingement for activities of daily living ( ADL ) in flexion , extension , abduction , adduction and rotation ( p = 0.016 ) . Acetabular component cover and surface contact with the host bone were > 87 % in both groups . There was a significant difference between the navigated and the conventional groups ' Harris hip scores six weeks after surgery ( p = 0.010 ) . There were no significant differences with respect to any clinical outcome at six months and one year of follow-up . The navigated ' femur-first ' technique improves the potential ROM for ADL without prosthetic impingement , although there was no observed clinical difference between the two treatment groups PURPOSE The purpose of this prospect i ve r and omized study was to assess biomechanical , radiographic , and functional results after single-bundle anterior cruciate ligament ( ACL ) reconstruction by use of a navigation system . METHODS ACL reconstruction was performed by use of the OrthoPilot navigation system ( B. Braun-Aesculap , Tuttlingen , Germany ) in 40 patients ( group 1 ) ; and in another 40 patients ,  surgery was done by the st and ard manual targeting technique  ( group 2 ) . The anterior laxity was measured with a KT-1000 arthrometer ( MEDmetric , San Diego , CA ) . Femoral and tibial tunnel position was evaluated radiologically according to the method described by Bernard and Hertel and by Harner et al. , respectively . The question naire-based Lysholm and International Knee Documentation Committee scales were included to compare the functional state in both groups . RESULTS The knees in group 1 were as stable as those in group 2 during the arthrometer testing , with a lower value of dispersion . The postoperative Lysholm and International Knee Documentation Committee scores had the same value in both groups . Statistical differences existed with regard to anterior-posterior femoral tunnel placement when the navigated and st and ard techniques were compared ; in the navigated group , more exact results were found . No significant complications were observed . CONCLUSIONS The only difference that we found between the navigated and st and ard groups was in radiographic tunnel position measurement . The computer-assisted navigation technique in our study result ed in more accurate tunnel placement in the femur ( but not the tibia ) than the traditional arthroscopic technique . However , the performed st and ard radiographic measurements are of limited precision in principle . Functional scales and stability tests gave similar results in both groups . LEVEL OF EVIDENCE Level I , therapeutic study To compare the alignment after computer-navigated total knee arthroplasty , 52 patients were r and omly allocated to 2 groups . Twenty-seven patients received a total knee arthroplasty with the aid of a kinematic computer-navigation system , and 25 patients received a total knee arthroplasty with the conventional method . Both groups were well balanced concerning demographic data and preoperative scores . At 3-month follow-up , the mechanical alignment of the leg reached the desired straight axis in more cases with the computer-navigated implantation . This difference was statistically significant . The femoral and tibial mechanical anteroposterior axis and the femoral and tibial sagittal tilt ( slope ) measured on sagittal x-rays were not significantly improved in this patient group 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 The purpose of this study was to compare conventional and navigated technique and a recently developed straight hip stem for uncemented primary total hip arthroplasty . The results of two consecutive implantation series of 42 patients ( nonnavigated ) and 42 patients ( navigated )  were analysed for implant positioning and complications . All surgeries were performed by the investigator . Radiographic analysis of cup position showed a significant improvement with reduced radiologic inclination ( 53 degrees nonnavigated /44 degrees navigated ; P < .001 ) and higher anteversion ( 7 degrees nonnavigated /12 degrees navigated ; P < .001 ) . The mean postoperative limb length difference was 6.2 mm ( SD , 9.0 for nonnavigated ) and 4.4 mm ( SD , 6.4 for navigated ) . Intraoperative and early postoperative complications were not different . No dislocation occurred in either group . There was one intraoperative trochanter fracture that was not revised ( nonnavigated ) and one revision because of a periprosthetic fracture caused by fall down during rehabilitation ( navigated ) . We conclude that acetabular implant positioning can be significantly improved by the use of navigated surgery technique . The data for postoperative limb length difference were still similar but within the expected range in both groups . The effect of improved cup positioning on mid and longterm results for both groups has to be investigated further
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 .