Primary repair for spontaneous quadriceps tendon rupture in patients with hemodialysis

Spontaneous quadriceps tendon rupture is not rare in patients with chronic renal failure needing dialysis due to the impaired collagen maturation in tendons. With transpatellar tunnel technique, the repair of the impaired tendon and successful healing are reported. The aim of this study is evaluate the functional results, strength and endurance of the quadriceps tendons after repair with transpatellar tunnel technique in hemodialysis patients with spontaneous quadriceps tendon ruptures. Primary repair with transpatellar tunnel technique is performed in 15 spontaneously ruptured quadriceps tendons of 9 patients with the mean age of 50,1 (6 bilateral, 3 unilateral ruptures). After a mean follow-up of 48.7 months, patients were evaluated with Lysholm score for functional evaluation. Isokinetic quadriceps strength and endurance measurements were performed with computerized dynamometer (CYBEX HUMAC–USA) and compared with a control group of 10 volunteers with chronic renal failure needing hemodialysis without quadriceps rupture history. The demographics of the study group and the control group were comparable in terms of age, body weight and dialysis year. 1 patient was deceased during follow-up due to end-stage renal failure. Of the 13 repairs evaluated, 1 repair failed after 3 months and needed revision surgery. Although at the latest follow-up all patients were doing active knee extension against gravity with their repaired quadriceps tendons and walk independently, the Lysholm score of the repair group (mean 75.3) was significantly lower than the control group (mean 93,2) (p: 0.009). The strength (peak torque) of the repaired quadriceps tendon was 43,6 Nm and was significantly lower than the control group (90,6 Nm) (p: 0.001). The endurance of the repaired tendon was also found to be significantly lower than the control group. 259 Nm and 625 Nm respectively (p: 0.001). Primary repair with transpatellar tunnel technique after spontaneous quadriceps ruptures in hemodialysis patients can provide acceptable functional results with active knee extension and independent walking ability. However the strength and endurance of the repaired tendon might be significantly lower than a impaired but unruptured quadriceps tendon.