BACKGROUND: For a tendon graft to function as an anterior cruciate ligament, the tendon must heal to the bone tunnel. We studied the effect of 4 weeks of implantation on the strength and stiffness of a tendon in a bone tunnel using two different fixation devices in an ovine model. HYPOTHESIS: The type of fixation device in anterior cruciate ligament reconstruction may affect early healing, which can be measured as the strength and stiffness of a tendon in a bone tunnel. STUDY DESIGN: Controlled laboratory study. METHODS: An extraarticular tendon graft reconstruction was performed in ovine tibias. The graft was fixed with either a bioresorbable interference screw or a WasherLoc. After 4 weeks of implantation the strength and stiffness of the complex and the tendon graft-bone tunnel interface were determined by incrementally loading specimens to failure. RESULTS: For the interference screw, the strength deteriorated 63% and the stiffness deteriorated 40%. For the WasherLoc, the strength was similar and the stiffness improved 136%. CONCLUSIONS: The type of fixation device determines whether the strength and stiffness of a tendon in a bone tunnel increases or decreases after implantation. CLINICAL RELEVANCE: The pace of rehabilitation may need to be adjusted based on the type of fixation device used to secure a soft tissue graft.
BACKGROUND: For a tendon graft to function as an anterior cruciate ligament, the tendon must heal to the bone tunnel. We studied the effect of 4 weeks of implantation on the strength and stiffness of a tendon in a bone tunnel using two different fixation devices in an ovine model. HYPOTHESIS: The type of fixation device in anterior cruciate ligament reconstruction may affect early healing, which can be measured as the strength and stiffness of a tendon in a bone tunnel. STUDY DESIGN: Controlled laboratory study. METHODS: An extraarticular tendon graft reconstruction was performed in ovine tibias. The graft was fixed with either a bioresorbable interference screw or a WasherLoc. After 4 weeks of implantation the strength and stiffness of the complex and the tendon graft-bone tunnel interface were determined by incrementally loading specimens to failure. RESULTS: For the interference screw, the strength deteriorated 63% and the stiffness deteriorated 40%. For the WasherLoc, the strength was similar and the stiffness improved 136%. CONCLUSIONS: The type of fixation device determines whether the strength and stiffness of a tendon in a bone tunnel increases or decreases after implantation. CLINICAL RELEVANCE: The pace of rehabilitation may need to be adjusted based on the type of fixation device used to secure a soft tissue graft.
Authors: Jinjin Ma; Michael J Smietana; Tatiana Y Kostrominova; Edward M Wojtys; Lisa M Larkin; Ellen M Arruda Journal: Tissue Eng Part A Date: 2011-09-23 Impact factor: 3.845
Authors: Rob P A Janssen; Jasper van der Wijk; Anja Fiedler; Tanja Schmidt; Harm A G M Sala; Sven U Scheffler Journal: Knee Surg Sports Traumatol Arthrosc Date: 2011-02-04 Impact factor: 4.342