Bioscrew fixation of patellar tendon autografts

Biodegradable interference screw fixation was studied using patellar tendon autografts in a randomized, prospective multicenter comparison of the PLLA Bioscrew and a metal interference screw. sixty-eight of 114 (60%) patients (34 Bioscrew and 34 metal screw) enrolled were available for follow up an average of 35 months after surgery (range 24-65). There were 42 males and 26 females with an average age of 29 years (16-50). Tourniquet times and associated surgical findings were similar for the two groups. Postoperative KT, Tegner, and Lysholm scores were not statistically different between the two groups. Average follow up KT maximum manual side-to-side difference was 0.9 mm for Bioscrews and 1.4 mm for metal screws. Postoperative Lachman and pivot shift testing were equivalent for the two groups. Other than six of the 7 mm Bioscrews breaking during insertion in the femoral tunnel, there were no problems related to the PLLA implants. No statistical difference was found between the Bioscrew and the metal screw groups, and there were no osteolytic or other reactive bone changes observed associated with the PLLA Bioscrew. These data indicate that the PLLA Bioscrew functions reliably as an interference fixation screw for patellar tendon autografts.