To report the technique of modified Thompson quadricepsplasty with postoperative treatment using string tie and the results for stiff knees.

From June 1987 to June 1997, we evaluated the results of 20 knees of 19 patients who were managed with modified Thompson quadricepsplasty for the stiff knee and were followed up for an average of 29 months (range, 18 to 49 months). We performed modified Thompson quadricepsplasty, which included arthrolysis, anterolateral or lateral approach, transverse incision on tensor fascia lata, release of middle and distal third of quadriceps muslce. If the knee flexion was less than 130 degree, Z-plasty on distal tendinous portion of rectus femoris was performed. Postoperatively, the knees were flexed with string tie for 3 hours. And then the knees were extended for 3 hours. This periodic passive exercise was started by the 21st day after the surgery.

The average gain in flexion from preoperative to postoperative was 74.7 degree±25.1 degree. At the latest follow-up, the average loss of range of motion from that obtained in the operating room was 5.3 degree±7.2 degree. According to Judet's assessment of results, there were 17 excellent and 3 good results. There was one wound infection but it resolved after wound care and intravenous antibiotics for 3 weeks.

The modified Thompson quadricepsplasty and postoperative care with string tie provided good results for the stiff knee.