A study of quadriceps excursion, torque, and the effect of patellectomy on cadaver knees.

Ten cadaver legs were mounted on a loading frame, and normal values for quadriceps excursion and tibial force were established with a constant quadriceps tension. The mean excursion of the quadriceps was 66.2 +/- 5.51 millimeters from zero to 90 degrees of knee flexion. After examining each 10-degree increment of motion we found that the maximum excursion of the quadriceps (9.49 +/- 1.35 millimeters) occurred between 30 and 40 degrees. The minimum excursion of 5.40 +/- 0.67 millimeters was found between 80 and 90 degrees of knee flexion. Incremental excursion of the quadriceps during 10-degree increments of knee flexion showed a correlation coefficient of 0.94 when compared with mean tibial torque (p less than 0.001). Patellectomy decreased excursion of the quadriceps to 51.3 +/- 1.30 millimeters from zero to 90 degrees of knee flexion. Torque was decreased by roughly 40 per cent of maximum from zero to 40 degrees of knee flexion.