A literature review of robotic systems showed that these systems can , similarly to computer navigation , reliably improve lower leg alignment , component positioning and soft tissues balancing .
Findings in this study suggest that computer navigation or robotic assistance may help managing these multiple variables and could improve outcomes .
Recently , there is a growing interest in surgical variables that are intraoperatively controlled by orthopaedic surgeons , including lower leg alignment , component positioning and soft tissues balancing .
Since more tight control over these factors is associated with improved outcomes of unicompartmental knee arthroplasty and total knee arthroplasty ( TKA ) , several computer navigation and robotic-assisted systems have been developed .
Although mechanical axis accuracy and component positioning have been shown to improve with computer navigation , no superiority in functional outcomes has yet been shown .
This could be explained by the fact that many differences exist between the number and type of surgical variables these systems control .
Most systems control lower leg alignment and component positioning , while some in addition control soft tissue balancing .
Finally , robotic-assisted systems have the additional advantage of improving surgical precision .
Manually controlling all these surgical variables can be difficult for the orthopaedic surgeon .
Navigation of total knee arthroplasty: rotation of components and clinical results in a prospectively randomized study
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
A literature review of robotic systems showed that these systems can , similarly to computer navigation , reliably improve lower leg alignment , component positioning and soft tissues balancing .
Findings in this study suggest that computer navigation or robotic assistance may help managing these multiple variables and could improve outcomes .
Recently , there is a growing interest in surgical variables that are intraoperatively controlled by orthopaedic surgeons , including lower leg alignment , component positioning and soft tissues balancing .
Since more tight control over these factors is associated with improved outcomes of unicompartmental knee arthroplasty and total knee arthroplasty ( TKA ) , several computer navigation and robotic-assisted systems have been developed .
Although mechanical axis accuracy and component positioning have been shown to improve with computer navigation , no superiority in functional outcomes has yet been shown .
This could be explained by the fact that many differences exist between the number and type of surgical variables these systems control .
Most systems control lower leg alignment and component positioning , while some in addition control soft tissue balancing .
Finally , robotic-assisted systems have the additional advantage of improving surgical precision .
Manually controlling all these surgical variables can be difficult for the orthopaedic surgeon .