Frank M Ivey

University of Texas Medical Branch at Galveston, Galveston, TX, United States

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Publications (2)6.21 Total impact

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    ABSTRACT: To evaluate the biomechanical properties of 3 anterior cruciate ligament (ACL) reconstruction femoral fixation devices in a porcine model with implantation on both the lateral femoral cortex and the anterior femoral cortex. ACL reconstructions with an 8-mm porcine tendon graft were performed on 48 porcine femurs with the EndoButton CL (Smith & Nephew, Andover, MA), ToggleLoc with ZipLoop technology (Biomet Sports Medicine, Warsaw, IN), or EZLoc (Biomet Sports Medicine). In 8 specimens for each implant, the femoral tunnel was drilled from the 10:30 surgical position out the lateral cortex. In another 8 specimens for each implant, the tunnel was drilled from the 10:30 position to a standardized anterior femoral surface. Cyclic testing was performed on an MTS testing machine (MTS, Eden Prairie, MN) from 50 N to 450 N for 2,000 cycles, followed by load-to-failure testing in specimens that survived. The cortical thickness and location of the implant exit were recorded. In the lateral femur group, 0 of the EZLoc devices, 2 of the ToggleLoc devices, and 3 of the EndoButtons completed cyclic testing. In the anterior femur group, 1 of the EZLoc devices, 5 of the ToggleLoc devices, and 5 of the EndoButtons completed cyclic testing (P = .012). In the anterior femur group, the ToggleLoc exhibited higher 2,000-cycle elongation (5.46 +/- 1 mm) than the EndoButton (3.55 +/- 0.6 mm) (P = .005). The EndoButton showed a higher first failure load (1,190.9 +/- 150.0 N) than the ToggleLoc (912.6 +/- 82.4 N) (P = .007). The anterior cortex (1.4 mm) was thinner than the lateral cortex (1.7 mm) (P = .0002). The EndoButton provided the strongest ACL femoral fixation with significantly less graft-implant elongation and significantly higher failure loads. It was also shown in a porcine model that implants on the anterior cortical surface perform better than those on the lateral surface. Increased cortical thickness, in the range tested, was not associated with improved implant performance in the porcine model. The EndoButton provided the best ACL femoral fixation of the devices tested.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 06/2010; 26(6):796-807. · 3.10 Impact Factor
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    ABSTRACT: A biomechanical study was undertaken to determine whether equal-stress or equal-tension tensioning of anterior cruciate ligament 4-stranded semitendinosus and gracilis grafts provides a stronger graft construct when testing to ultimate failure. Eighteen fresh-frozen cadaveric semitendinosus and gracilis tendons were each positioned over a cylinder rod/cryo-clamp connected to an MTS machine (MTS Systems, Eden Prairie, MN) by another cryo-clamp. In the equal-tension group the 4 strands were equally tensioned by weights. In the equal-stress group a tensioning device applied equal stress based on the cross-sectional areas of the tendons. The tendons were preconditioned with 10 cycles and then tested to failure. Graft creep during the preconditioning cycle was determined by MTS measurement of the change in clamp distance. The maximum loads of 4-stranded semitendinosus and gracilis grafts tensioned by equal stress were found to be similar to those of the grafts tensioned by equal tension (2,803 +/- 431 N and 2,772 +/- 461 N, respectively). The loads at first failure were 2,640 +/- 468 N and 2,452 +/- 461 N, respectively (P = .17). The preconditioning cycles showed that the equal-stress group resisted graft creep significantly better (P = .0003). The strength of the 4-stranded hamstring graft when equally tensioned or equally stressed was equivalent when tested to failure. After 10 preconditioning cycles, equal stress resisted graft creep significantly better. Equal-stress tensioning offers an alternative tensioning method for 4-stranded hamstring grafts. Equal-stress tensioning offers an alternative tensioning method for 4-stranded hamstring grafts.
    Arthroscopy The Journal of Arthroscopic and Related Surgery 01/2009; 24(12):1323-9. · 3.10 Impact Factor

Publication Stats

15 Citations
6.21 Total Impact Points

Institutions

  • 2009–2010
    • University of Texas Medical Branch at Galveston
      • Department of Orthopaedic Surgery and Rehabilitation
      Galveston, TX, United States