This study reports the results of a treatment for posterolateral instability of the knee with a modified Muller's method.

Fourteen patients (3 acute and 11 chronic cases) with a modified Muller's method and with a follow-up period of more than 12 months, average follow-up period of 15 months (range, 12 to 22 months) was included. We recorded and analysed the physical findings (reverse Lachmann test and varus stress test at 30 degree knee flexion), stress roentgenograms at preoperative 8 postoperative 12 months, magnetic resonance imagings and Lysholm score at preoperative, postoperative 3, 12 months and the last follow-up.

Average Lysholm score was 65A preoperatively and 90.0 at postoperative 12 months. The posterolateral stabilities of the knee were improved in all cases postoperatively, according to the clinical stability tests (reverse Lachmann test and varus stress test at 30 degree knee flexion) and stress roentgenograms.

Modified Muller's technique-the reconstruction of the popliteus tendon using iliotibial band-represents an excellent method to restore tension in the posterolateral complex of the acutely and chronically injured knee.