MUSCLE FUNCTION AFTER MIDSHAFT FEMORAL SHORTENING - A PROSPECTIVE-STUDY WITH A 2-YEAR FOLLOW-UP

We performed isokinetic knee testing to assess thigh muscle function i n ten patients (12 legs) before and after mid-shaft femoral shortening averaging 46 mm (27 to 70). Tests were at angular velocities of 60 de grees/sec and 180 degrees/sec, and were performed preoperatively and a fter 3, 6, 12 and 24 months. Isokinetic tests at two years showed a si gnificant reduction in muscle function in both quadriceps and hamstrin gs, but recovery of function was significantly better for the hamstrin gs. There was a linear relationship with correlation of r(2) = 0.31 to 0.86 between loss of muscle force at two years and the magnitude of s hortening. Long-term loss of muscle force should be expected after a m id-shaft shortening of the femur of more than 10%.