Ligament graft initial fixation strength using biodegradable interference screws.
The objective of this study was to evaluate the initial fixation strength of three types of biodegradable interference screws [an Endo Fix, 7 x 25 mm polyglycolic acid, non-self-tapping (Acufex); a biodegradable interference screw, 7 x 23 mm poly-L-lactic acid, self-tapping (Arthrex); a Bioscrew, 7 x 25 mm poly-L-lactic acid, self-tapping (Linvatec)] in comparison to a titanium interference screw (Linvatec, 7 x 25 mm) in anterior cruciate ligament reconstruction using a bone-patellar tendon-bone graft. Porcine lower limbs were used. To control for specimen related bias, bone mineral density of each tibia was measured. All specimens were loaded to failure. Failure mode was determined by visual analysis. The maximum load to failure [mean (SD)] was 785 (87) N (titanium screw), 555 (60) N (Acufex), 592 (211) N (Arthrex), and 844 N (Linvatec). The primary fixation strength of the titanium screw and the Linvatec screw was significantly higher (p < 0.05) than the primary fixation strength of the Arthrex screw and the Acufex screw. There was no difference in bone mineral density between the groups. With respect to primary fixation strength, all biodegradable screws were strong enough to allow accelerated rehabilitation. From this point of view the biodegradable screws may be a reasonable alternative to titanium interference screws.
Department of Orthopaedic Surgery, University Hospital, University of Saarland, Homburg/Saar, Germany.
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Rupp
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Seil
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Schneider
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Kohn
D020341:Absorbable Implants; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery; D001696:Biomechanical Phenomena; D015519:Bone Density; D001863:Bone Screws; D004867:Equipment Design; D004868:Equipment Failure; D007595:Joint Prosthesis; D019344:Lactic Acid; D011091:Polyesters; D011100:Polyglycolic Acid; D011108:Polymers; D013314:Stress, Mechanical; D013552:Swine; D013710:Tendons / Q000601:surgery; D013718:Tensile Strength; D013977:Tibia / Q000601:surgery
D011091:Polyesters; D011108:Polymers; D011100:Polyglycolic Acid; D019344:Lactic Acid; C033616:poly(lactide)