PURPOSE: The purpose of this study was to evaluate the detrimental effects of interference screw fixation on soft tissue anterior cruciate ligament (ACL) reconstruction after 6 weeks and compare them with a cross-pin technique. METHODS: In an intra-articular model, ovine soft tissue grafts were fixed with two 3.3-mm biodegradable pins or with interference screws. Maximum load, yield load, and stiffness of the femur-graft-tibia complex were evaluated immediately after surgery and 6 weeks postoperatively. RESULTS: For knees with interference screw fixation, strength deteriorated by 81% and stiffness deteriorated by 67%. For knees with double cross-pin fixation, strength deteriorated by 48% and stiffness improved by 52%. These differences were statistically significant. At the time of surgery, all grafts failed by slippage of the graft past the screw or by cross-pin failure. At 6 weeks postoperatively, the grafts of both groups failed at the tibial or femoral tunnel entrance. CONCLUSIONS: After 6 weeks, the biomechanical characteristics of grafts that were fixed with cross-pins were superior to those of grafts after interference screw fixation. CLINICAL RELEVANCE: Because of significantly inferior biomechanical stability after interference screw fixation, a less aggressive program of rehabilitation might be recommended.
PURPOSE: The purpose of this study was to evaluate the detrimental effects of interference screw fixation on soft tissue anterior cruciate ligament (ACL) reconstruction after 6 weeks and compare them with a cross-pin technique. METHODS: In an intra-articular model, ovine soft tissue grafts were fixed with two 3.3-mm biodegradable pins or with interference screws. Maximum load, yield load, and stiffness of the femur-graft-tibia complex were evaluated immediately after surgery and 6 weeks postoperatively. RESULTS: For knees with interference screw fixation, strength deteriorated by 81% and stiffness deteriorated by 67%. For knees with double cross-pin fixation, strength deteriorated by 48% and stiffness improved by 52%. These differences were statistically significant. At the time of surgery, all grafts failed by slippage of the graft past the screw or by cross-pin failure. At 6 weeks postoperatively, the grafts of both groups failed at the tibial or femoral tunnel entrance. CONCLUSIONS: After 6 weeks, the biomechanical characteristics of grafts that were fixed with cross-pins were superior to those of grafts after interference screw fixation. CLINICAL RELEVANCE: Because of significantly inferior biomechanical stability after interference screw fixation, a less aggressive program of rehabilitation might be recommended.
Authors: Jung Ho Noh; Seung Rim Yi; Sang Jun Song; Seong Wan Kim; Woo Kim Journal: Knee Surg Sports Traumatol Arthrosc Date: 2011-02-03 Impact factor: 4.342
Authors: Michael T Hirschmann; Tom Adler; Helmut Rasch; Rolf W Hügli; Niklaus F Friederich; Markus P Arnold Journal: Sports Med Arthrosc Rehabil Ther Technol Date: 2010-09-16
Authors: Stephan Frosch; Anne Rittstieg; Peter Balcarek; Tim Alexander Walde; Jan P Schüttrumpf; Martin M Wachowski; Klaus M Stürmer; Karl-Heinz Frosch Journal: Knee Surg Sports Traumatol Arthrosc Date: 2012-11 Impact factor: 4.342