The natural history of flexion contracture in total knee arthroplasty. A prospective study.

A prospective study was carried out to document the natural history of flexion contractures of the knee after total knee arthroplasty (TKA). Thirty-five knees in 33 patients with TKA were followed for a mean duration of 55 weeks. In no case did the surgical procedure include excessive bony resection in order to correct a flexion contracture. Standard goniometric measurements were used to determine the knee flexion contractures preoperatively and postoperatively while the patient was anesthetized and at each successive follow-up visit. All preoperative and postoperative flexion contractures were less than 30 degrees. The mean fixed flexion deformity of the entire group preoperatively was 12.9 degrees; immediately postoperatively, 14.8 degrees; and at final follow-up, 2.9 degrees. No difference was found in the amount of flexion contracture present at final follow-up evaluation with respect to age or gender. The impression that fixed flexion contractures must be corrected at the time of arthroplasty has led to the intraoperative removal of excess bone from the distal femur and/or proximal tibia. The present findings indicate that knee flexion contractures can significantly improve after TKA. There appears to be little, if any indication for excessive removal of bone in an attempt to achieve intraoperative correction.