Background: There is relatively little information about quadriceps tendon tears after total knee arthroplasty. The purpose of this study was to determine the prevalence of this condition and the outcomes of patients who had a tear of the quadriceps tendon after a total knee arthroplasty.

Methods: From a cohort of 23,800 primary total knee arthroplasties, we identified twenty-four patients who had a rupture of the quadriceps tendon postoperatively. Ten additional patients had the total knee arthroplasty done elsewhere and were referred for care after sustaining a tear of the quadriceps tendon. Thus, the study group consisted of thirty-four patients, and all had at least two years of follow-up. Eleven patients had a complete tear, and twenty-three had a partial tear.

Results: The prevalence of a quadriceps tendon tear after total knee arthroplasty was 0.1% (twenty-four of 23,800). Seven patients with a partial tear were treated nonoperatively, and all had a satisfactory outcome. One patient with a complete tear was treated nonoperatively and had an unsatisfactory result. Of the ten patients treated operatively after a complete tear, four subsequently had rerupture of the repaired tendon and four had a satisfactory outcome. Of the sixteen patients with a partial tear treated operatively, only one had rerupture and twelve had a satisfactory outcome. Complications occurred in eleven of the twenty-six patients managed operatively.

Conclusions: The prevalence of complications was high, and the outcomes were poor for seven of the eleven patients who had a complete quadriceps tendon tear after total knee arthroplasty. Patients who sustained a partial tear and were treated nonoperatively had no complications and had uniformly good outcomes.

Level of Evidence: Prognostic study, Level IV. See Instructions to Authors for a complete description of levels of evidence.