Primary total knee arthroplasty using rotating-hinge prosthesis in severely affected knees

A rotating-hinge total knee prosthesis may be utilized for the treatment of global instability or severe bone loss around the knee. The outcome of primary total knee arthroplasty (TKA) using Endo-Modell (Link(A (R))) rotating-hinge prosthesis was evaluated. Retrospectively, review of 50 cases (40 patients) at a mean follow-up of 15 years (range, 10-18) who underwent primary TKA using Endo-Modell (Link(A (R))) was performed. Indications included severe primary osteoarthritis with substantial ligament laxity, severe rheumatic arthritis with extreme ligament instability and bone loss, supracondylar nonunion, charcot arthropathy, and posttraumatic arthritis. Knee Society Score (KSS) and radiographic analysis were done for preoperative and at latest follow-up. Statistical analysis was done using the Student's t test with the level of significance of p < 0.05. Overall, the rotating-hinge arthroplasty resulted in improved knee functioning. The KSS improved (p < 0.001) from a preoperative mean of 38 +/- A 14.3 (SD) points to a postoperative mean of 73 +/- A 12.8 points; the functional score improved (n.s.) from 36 +/- A 19.5 points to 47 +/- A 23.5 points. Mean range of motion at the most recent clinical follow-up evaluation was 102 +/- A 9A degrees. However, all (100%) patients needed some form of assisted devices for walking and a relatively large number of deep infections (14%) were encountered. Reconstruction with a rotating-hinge total knee prosthesis provided substantial improvement in function and reduction in pain. However, the possibility of assisted walking and high rate of deep infection should be encountered. Retrospective therapeutic study, Level IV.