[Trauma-induced tears of the quadriceps tendon: 47 cases]

A torn quadriceps tendon is an exceptional finding generally observed after high-energy knee trauma in patients over 40 who present a sprain-like syndrome or after low-energy trauma in elderly subjects who experience knee instability. We reviewed a series of 47 cases of traumatic quadriceps tendon tears treated between 1976 and 1996 in order to evaluate outcome after surgical repair.

Clinical diagnosis was the rule. Forty-two patients, mean age 55 years (range 17-92) were treated for tears of one or both quadriceps tendons subsequent to low-energy trauma (40 tears) or high-energy trauma in younger subjects. The diagnosis was established early in all cases except eight (diagnosis at three weeks to one year). Surgical repair was performed in all cases except one. After surgery, the knee was either immobilized with a plaster cast or held in a removable splint to allow early mobilization.

Average time to recovery compatible with daily life or occupational activities was four months. Recovery was not complete at this time. Long-term follow-up revealed that complete recovery with very good or good subjective results was achieved in 90% of the cases. Complete joint motion and normal quadriceps force was achieved in 80% of the cases. Patients who started rehabilitation exercises early generally achieved less satisfactory results although no significant correlation was identified with objective clinical variables.

Quadriceps tendon tear is a clinical diagnosis which does not require complementary exploration for confirmation. Plain x-rays may be useful to identify associated bony lesions and specific signs of tendon tears. Early surgical repair followed by complete immobilization appears to be preferable for functional recovery allowing better recovery of muscle force without compromising flexion.