Functional results after surgical repair of quadriceps tendon rupture.

We present the long-term results of surgical repair of a traumatic rupture of the quadriceps tendon in a group of 24 patients with a mean age of 58 years. There were 21 male and 3 female patients. Fifteen patients were seen for clinical control after a mean follow-up of 75 months and they all presented with some quadriceps muscle atrophy. Twelve patients had normal knee mobility, three had a flexion deformity of 10 degrees and two had less than 120 degrees of knee flexion. Active knee extension was normal in all patients. Three patients experienced some decrease in stability of their knee joint. Subjectively all patients were satisfied with the result. Nine patients underwent a Cybex-test for evaluation of the isokinetic force of knee flexion and extension, with a comparison between the injured and the uninjured side. For concentric force there was a mean deficit at low speed of 36.1% for the quadriceps muscle; at high speed it was 28.2%. For the knee flexors, the deficits were 30.7% and 27.2% respectively. Regarding eccentric force, the mean deficit for knee extensors was 13.8% and 0.25% respectively and for knee flexors 6.5% and 5.5% respectively.