Preoperative templating of femoral and tibial components can assist in choosing the appropriate implant size prior to TKA. While weight bearing long limb roentograms have been shown to provide benefit to the surgeon in assessing alignment, disease state, and previous pathology or trauma, their accuracy in size prediction is continually debated due to scaling factors and rotated views. Further, they represent a static time point, accounting for boney anatomy only. A perceived benefit of robotic-assisted surgery is the ability to pre-operatively select component sizes with greater accuracy based on 3D information, however, to allow for flexibility in refining based on additional data only available at the time of surgery. The purpose of this study was to determine the difference of pre-operative plans in size prediction of the tibia, femur, and polyethylene insert. Eighty four cases were enrolled at three centers as part of an Investigational Device Exemption to evaluate a robotic-assisted TKA. All patients had a CT scan as part of a pre-operative planning protocol. Scans were segmented and implant sizes predicted based on the patients boney morphology and an estimated 2mm cartilage presence. Additional information such as actual cartilage presence and soft tissue effects on balance and kinematics were recorded intra-operatively. Utilizing this additional information, surgical plans were fine tuned if necessary to achieve minimal insert thickness and balance. Data from the Preoperative CT plan sizing and final size were compared to determine the percentage of size and within one size accuracy.Introduction
Methods
Total knee arthroplasty (TKA) is a well established treatment option for patients with end stage osteoarthritis. Conventional TKA with manual instruments has been shown to be a cost effective and time efficient surgery. While robotic-assisted operative systems have been shown to have benefits in surgical accuracy, they have also been reported to have longer surgical times. The purpose of this work was to determine surgical time and learning curve for a novel robotic-assisted TKA platform. Eighty-five subjects underwent robotic-assisted TKA by one of three investigators as part of an FDA and IRB approved Investigational Device Exemption (IDE). All patients received a cruciate retaining total knee implant system. Intra-operative safety, Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Knee Society Scores (KSS) were collected pre-operatively and at three month follow-up. In addition, surgical times were collected as part of a TKA work flow. To identify activities related to surgical steps required for robotic procedures specific time stamps were determined from the system. Capture of the hip center to final bone cut was used to define case time and identify robotic learning curve. Descriptive statistics were used to analyze results.Introduction
Methods
