Acetabulum positioning affects dislocation rates, component impingement, bearing surface wear rates, and need for revision surgery. Novel techniques purport to improve the accuracy and precision of acetabular component position, but may come have significant learning curves. Our aim was to assess whether adopting robotic or fluoroscopic techniques improve acetabulum positioning compared to manual THA during the learning curve. Three types of THAs were compared in this retrospective cohort: 1) the first 100 fluoroscopically guided direct anterior THAs (fluoroscopic anterior, FA) done by a posterior surgeon learning the anterior approach, 2) the first 100 robotic assisted posterior THAs done by a surgeon learning robotic assisted surgery (robotic posterior, RP) and 3) the last 100 manual posterior THAs done by each surgeon (total 200 THAs) prior to adoption of novel techniques (manual posterior, MP). Component position was measured on plain radiographs. Radiographic measurements were done by two blinded observers. The percentage of hips within the surgeons' target zone (inclination 30°–50°, anteversion 10°–30°) was calculated, along with the percentage within the safe zone of Lewinnek (inclination 30°–50°; anteversion 5°–25°) and Callanan (inclination 30°–45°; anteversion 5°–25°). Relative risk and absolute risk reduction were calculated. Variances (square of the SDs) were used to describe the variability of cup position.Background
Methods
Computer-assisted navigation is an established tool in hip and knee arthroplasty. This technology was introduced with the goals of greater precision in bone preparation and implant placement, potentially leading to improved clinical outcomes. Various navigation protocols exist, many of which require placement of temporary percutaneous pins in the operative field. Risks of pin placement have not been described. We conducted a retrospective review of 352 consecutive patients undergoing elective hip and knee surgery using computer-assisted navigation between January 2013 and December 2015, all with a minimum follow-up of 90 days. Navigation pins were placed using a standardized protocol into the iliac crest for hip arthroplasty or into the femoral and tibial diaphysis for knee arthroplasty. Postoperatively, all patients were allowed to weight bear as tolerated. Patient records were reviewed for operative details and clinical outcomes. Outcome measures included any pin site complications including direct neurovascular damage, fracture through a pin site, and pin site infection.Introduction
Methods
Total hip arthroplasty is considered to be one of the most successful orthopaedic interventions. Acetabular component positioning has been shown to affect dislocation rates, component impingement, bearing surface wear rates, and need for revision surgery. The safe zones of acetabular component positioning have previously been described by Lewinnek et al. as 5 to 25 degrees of cup version and 30 to 50 degrees of inclination. Callanan et al. later modified the inclination to 30 to 45 degrees. Our aim was to assess whether THA via robotic assisted posterior approach (PA) improves acetabular component positioning compared to fluoroscopic guided anterior approach THA (AA).Introduction
Methods
