Rotating Hinge Total Knee Arthroplasty RT-PLUS Solution: A Clinical and Radiographic FollowUp

Background: In total knee arthroplasty (TKA), there is still controversy surrounding the preferable prosthetic design and required amount of constraint. Indication for rotating hinge TKA includes primary and revision arthroplasty, with contradictory results. We present the first medium- to long-term results with the rotating hinge knee prosthesis RT-PLUS SOLUTION (Smith & Nephew Orthopaedics, Baar, Switzerland). Methods: A retrospective, non-randomized, observational, single centre study was conducted, in which 146 total knee replacements were performed in 136 patients between 2003 and 2012 using the RTPLUS SOLUTION rotating hinge knee (Smith & Nephew Orthopaedics, Baar, Switzerland). In 77 of the 146 cases, the system was used as a primary implant. The mean age of the population at time of index surgery was 76.3±10.4 years. Results: At final follow-up, 62 patients (62 knees) were available for clinical and radiological follow-up after a mean of 6.8±2.2 years. There were three revisions due to mechanical complications (loosening), and one septic revision. Ten year cumulative implant survival was 89.4% (95% confidence interval, 68.8%-96.7%). Radiolucent lines were observed in 36 cases. They were, however, clinically asymptomatic and without therapeutic consequences in all cases. Clinical outcome and patient satisfaction outcomes were in line with previous investigations. Conclusion: To our knowledge, these are the first medium- to longterm follow-up results with the RT-PLUS Solution. This rotating hinge knee shows good clinical and radiographical results and good longevity.