Volume 9, Issue 2 (February 2012)
Early Instability with Mobile Bearing Total Knee Arthroplasty: A Series of Twenty-Five Cases
Between Dec. 1987 and Jan. 2002, twenty-five cases of clinical instability following mobile bearing total knee arthroplasty with meniscal bearings or rotating platforms presented for evaluation at our institution. These cases were retrospectively identified. All were performed at outside institutions by a variety of surgeons. All clinical examinations were performed by the authors. Nine cases were revised at our institution. All twenty-five cases had clinical evidence of severe coronal plane instability and pain. Eight cases had polyethylene dislocation or subluxation evident radiographically and clinically. Four cases had extensor mechanism dysfunction. Eighteen cases had symptoms immediately postoperatively. Twenty-three of the twenty-five cases had symptoms within two years postoperatively. Any potential long-term benefit of design innovations must be balanced with known problems leading to early failure. This paper is a review of a previously published manuscript by Dr.’s Moskal and Ridgeway [Ridgeway, S. R. and Moskal, J. T., “Early Instability with Mobile Bearing Total Knee Arthroplasty: A series of twenty-five cases,” J. Arthroplasty, Vol. 19, No. 6, 2004, pp. 686–693]. The current manuscript has been updated with additional discussion and references covered in his planned presentation.