Long-Term Results of Third Generation of Rotating Hinge Arthroplasty in Patients with Poliomyelitis

Abstract

Background: Total knee arthroplasty (TKA) for poliomyelitis patients is controversial due to its higher complication rate compared with that of TKA for osteoarthritis. In this study we evaluated the results, at a minimum of 10 years, of a consecutive series of third-generation rotating hinge total knee arthroplasties (RHKs) in patients affected by poliomyelitis. Methods: We conducted a retrospective analysis of 14 patients (15 TKA) performed between January 2000 and October 2021 that underwent a third-generation rotating hinge arthroplasty (Nex Gen RHK Zimmer). The clinical results using the American Knee Society Score (AKSS) were evaluated at an average follow-up of 154 months (min 120–max 216 months). Result: Of the 15 cases, 2 were lost at follow-up and 1 was excluded by the final evaluation due to infection. Of the remaining 12 cases at the final follow-up, the average AKKS clinical score improved from 30.08 points preoperatively, to 78.83 points postoperatively, while the average AKKS function score improved from 29.17 points to 56.25 points. We report only one intraoperative complication consisting of a femoral fracture at the tip of the stem, and a case of patellar fracture occurred 3 months after the index procedure. The presence of radiolucent lines was sporadic, while radiosclerotic lines were commonly visible around the stem extension, predominantly at the tip. Conclusions: The third generation of rotating hinge knee replacement has proved to be effective in polio patients, improving clinical and functional scores, and no cases of mechanical failure occurred.