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Minerva Ortopedica e Traumatologica 2007 April;58(2):193-206

Copyright © 2007 EDIZIONI MINERVA MEDICA

language: English

Current concepts of graft fixation in anterior cruciate ligament reconstruction using soft tissue grafts. Biomechanical aspects of different fixation strategies

Petersen W., Zantop T.

Department of Trauma Hand and Reconstructive Surgery Westfalian Wilhelms University Münster Münster, Germany

The fixation device chosen for the fixation of soft tissue anterior cruciate ligament (ACL) grafts is the primary restraint in the early postoperative phase. The literature distinguishes between aperture and extracortical fixation techniques. Extracortical fixation techniques provide a high ultimate failure load; however, the reported stiffness of these devices is low. Tunnel widening after soft tissue ACL reconstructions may be due to mechanical factors such as bungee cord and windshield wiper effect as well as biological factors such as synovial leak into the tunnel. Using aperture (anatomical) fixation devices as interference screws these effects could be prevented. To provide a sufficient fixation strength oversized interference screws are needed; however, results of animal studies have implicated that oversizing may inhibit tunnel/graft healing due to the high pressure within the tunnel. Hybrid fixation technique combining extracortical and aperture fixation device with a smaller interference screw could unite the advantages of both fixations. Transfemoral fixations provide a reasonable alternative. Systems suspending the loop of the graft (“suspension techniques”) can be distinguished from devices piercing the graft close to the joint line (“piercing techniques”). These fixation devices reveal a high ultimate failure load and could be determined as semianatomical. In an animal study a piercing technique showed superior structural properties 6 weeks after ACL reconstruction when compared to an interference screw fixation. Tunnel widening has been reported after reconstructions using a suspension technique.