[Histologic studies of replacement of the anterior cruciate ligament with PDS-augmented patellar tendon transplants]

The bone-patellar tendon-bone graft is currently the best substitute for the anterior cruciate ligament (ACL). To improve the results we compared a modified Jones procedure with an additional PDS augmentation. In 25 sheep the ACL was reconstructed in the left knee after total resection. The only resection of the ACL was done in all right knees. One year postoperative 21 sheep remained in the experiment and came to evaluation. There were 10 modified Jones procedures and 11 PDS augmentations. In both groups, the central one-third of the patellar tendon was implanted through a femoral and tibial drill hole for reconstruction of the anterior cruciate ligament. The transplants were fixed on both ends with a 1-mm cord of polydioxanon (PDS), a soft preload of 50 N was given with a spring balance and the ends of the cords were fixed with a screw and a washer. In the second group we did an additional augmentation with a doubled cord of 2 mm PDS. Early mobilization and weight-bearing was allowed. Throughout the observation period all animals were labelled for fluorescence microscopy. One year after resection of the ACL without reconstruction there were totally destroyed joints. Histology showed damaged menisci and joint surfaces without any cartilage as a sign of severe arthrosis. The macroscopic aspect of the transplants showed strong ligaments coated totally by a synovial membrane with good vascularization. Only little signs of degeneration were to be seen.(ABSTRACT TRUNCATED AT 250 WORDS)