Isokinetic performance of the thigh muscles after tibial plateau fractures.

The isokinetic performance of thigh muscles was evaluated in 37 patients at an average of 7 years after sustaining a fracture of the tibial plateau. The mean torque deficit in the quadriceps of the injured limb was an average of 15% at a speed of 60 degrees/s and 16% at 180 degrees/s, while the corresponding deficits in the hamstrings were 3% and 8%. The radiological appearance of the injured knee correlated significantly to the quadriceps deficit at both speeds. Limited knee movement and thigh atrophy also correlated with the deficit at the lower speed. The strength deficit tended to decrease during follow-up. A multiple step-wise regression analysis showed that the radiological result, length of follow-up and thigh atrophy accounted for 47% of the variation in loss of quadriceps strength. At the higher speed, the functional result was associated with the deficit in quadriceps strength, and older patients had greater deficits than younger. Regression analysis indicated that the radiological and functional result accounted for 31% of the variation in quadriceps strength. Anatomical restoration of the tibial plateau and good muscle rehabilitation are important in obtaining good long term results after this fracture.