Twenty-year evaluation of meniscal bearing and rotating platform knee replacements

Abstract

Clinical results of the initial cemented and cementless series of 373 New Jersey Low Contact Stress total knee replacements in 282 patients surviving at least 10 years were analyzed using a strict knee scoring scale. The study showed excellent, good, fair, or poor results in 68.1%, 29.8%, 2.1%, or 0% of primary posterior cruciate-retaining meniscal bearing knee replacements, 46.7%, 53.3%, 0%, or 0% results in primary cemented rotating platform knee replacements, and 68.1%, 29.8%, 2.1%, or 0% results in primary cementless rotating platform knee replacements, respectively. Radiographic evaluation at minimum 10-year followup showed stable fixation of all components, no gross migration but significant osteolysis requiring bearing exchange and bone grafting in three cementless rotating platform knee replacements (1.8%) in three patients who underwent previous surgeries at an average of 10.2 years from the index surgery. Survivorship of the patients who underwent primary cementless posterior cruciate-retaining meniscal bearing knee replacements with an end point of revision for any mechanical reason was 97.4% at 10 years and 83% at 16 years; using an end point of a poor clinical knee score the survivorship was 98.9% at 10 years and at 16 years. Survivorship of the patients who underwent primary cemented rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 97.7% at 10 years and at 20 years. Survivorship of the patients who underwent cementless rotating platform knee replacements with end points of revision for any mechanical reason or a poor clinical knee score was 98.3% at 10 years and at 18 years.