The patellofemoral joint in total condylar knee arthroplasty. Pros and cons based on five- to ten-year follow-up observations.

In this report, 100 knees in 77 patients, with an average age of 65, were followed for a period between five and 10 years. Rheumatoid arthritis was the diagnosis in 43 patients and osteoarthritis in 34 patients. The majority had varus, valgus, and biplane deformities. Twenty-one patients underwent bilateral procedures; all but one had patellar replacement. Over 90% of the knees were rated good to excellent according to The Hospital for Special Surgery Knee Disability Score Sheet. Of the 34 osteoarthritic patients (40 knees), 24 or 71% could walk ten blocks and beyond. Ten patients, or 29%, could walk between one and ten blocks. Further ambulation was restricted only by overall poor health and age (most were 74 years of age or older). Twenty-four patients, or 71%, could ascend and descend stairs without support, while six (18%) relied on bannister support when descending stairs. Four patients (11%) required bannister support for both ascending and descending stairs. Among the complications seen in this series were one loose patella and another with osteonecrosis of the anterior surface. No dislocations occurred, but 14 patellae showed tilt on skyline view roentgenograms, indicating a tight lateral retinaculum. In view of the good to excellent results achieved in the majority of patients, and the low morbidity associated with replacement, it is recommended that the patellofemoral joint be replaced in the course of total knee arthroplasty. When careful attention is paid to technical details, this procedure improves the quality of the arthroplasty.