Semitendinosus augmentation of acute patellar tendon repair with immediate mobilization.

We report four cases of acute midsubstance rupture of the patellar tendon that were treated with primary surgical repair along with semitendinosus autograft augmentation. The goal of this treatment was to allow immediate mobilization of the knee with a single operative procedure. We also demonstrate a technique for determining patellar position intraoperatively. Patients were tested for functional performance at an average final followup of 40 months (range, 20 to 66) including hamstring and quadriceps muscle strength evaluation, completion of a functional questionnaire, functional test performance, range of motion assessment, and patellar tendon length measurement. In evaluating the results, all cases were essentially identical to the nonoperated side, except one knee that had multiple associated ligament injuries. The multitude of injuries to this knee are likely the cause of the discrepancy. Immediate midsubstance patellar tendon repair with semitendinosus augmentation allowed immediate mobilization, which decreased the recovery period and improved the outcome of rehabilitation. Furthermore, a second surgery for hardware removal was not needed. These two factors--early and improved rehabilitation and the decreased chance of a second surgery--affect the cost of treatment of this injury. All isolated patellar tendon injuries in the study had excellent function at followup. For these reasons, we recommend this procedure for acute patellar tendon ruptures.