OBJECTIVETo investigate the feasibility of reconstruction of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) with hamstring tendons knot implant fixation.

METHODSFifty-two cases of ACL and PCL old injury were reconstructed under the arthroscopy with double bundles hamstring tendons knot implant fixated in the bottle-necked femoral tunnel. The tibia side were fixated by tendon weave suture cross tied a knot at the bone bridge of tibia. In this group reconstruction of ACL was in 25, PCL and ACL at the same time reconstruction in 15, PCL in 12. The failure test and displacement evaluation were used to study the biomechanics of reconstruction of ACL by hamstring tendon knot implant fixation (n = 13) in porcine knees. The control group were reconstructed with bone-patellar tendon-bone B-PT-B and interference screw (n = 11). The tibia side tendon weave suture immobility by cross tied a knot at the tibia bone bridge (n = 7) and interference screw in the tibia tunnel (n = 8).

RESULTSForty-nine cases were followed up, average 14.6 months. The results of Lanchman test was negative in 46 cases, positive in 3 cases. Preoperative Lysholm score was 56.7, and postoperative was 92.8. According to the knee joint effective evaluate standard, 46 were excellent and 3 good. The maximal pull-out force of hamstring tendons knot implanted fixation had been greater than B-PT-B fixation by interference screw. There were similar displacement in 100 N and 400 N load between hamstring tendons knot implant fixation and B-PT-B (P > 0.05). Peak force test maximal displacement evaluation and failure energy absorption measurement showed that hamstring tendons knot implant fixation was significantly greater than B-PT-B (P < 0.01). The failure test and displacement evaluation of tendon fixation by weave suture knot at the tibia bone bridge cross tie were greater than B-PT-B fixation by interference screw.

CONCLUSIONThe methods of reconstruct of ACL and PCL by hamstring tendons knot implant fixation are feasible. The advantages include: it is biological fixation, not machine fixation; it may benefit for tendons with bone tunnel healing and decrease medical cost. Decreasing or eliminating displacement is helpful to prevent relaxation after reconstruction of ACL and PCL.