The press-fit condylar modular total knee system with a posterior cruciate-substituting design. A concise follow-up of a previous report.
The purpose of the present study was to determine the long-term results of a series of 150 consecutive primary posterior stabilized modular knee arthroplasties that had been performed in 118 patients with use of a circumferential tibial insert capture as described in a previous report, published in 1997. The patients were evaluated with use of a patient-administered questionnaire; Knee Society clinical, functional, and radiographic scoring systems; and Kaplan-Meier survivorship analysis. A good to excellent result was confirmed in seventy-six (90%) of the eighty-four patients (105 knees) with a mean duration of follow-up of twelve years (range, ten to thirteen years). At twelve years, the survival rate was 94.6% +/- 4.0% with failure for any reason as the end point and 98.3% +/- 2.4% with mechanical failure as the end point. Revision surgery was performed in five knees because of infection (two knees), dislocation (one knee), and substantial polyethylene wear with femoral osteolysis (two knees). We concluded that, while fixation failure is rare, polyethylene wear and osteolysis are emerging as important causes of failure.