Biomechanical properties of braided polyester tapes intended for use as intra-articular cranial cruciate ligament prostheses in dogs

Abstract

Objective - To determine the in vitro structural and material properties of braided, multifilament, nonabsorbable polyester tapes, used for intra-articuiar stabilization of cranial cruciate ligament-(CCL-) deficient stifle joints in dogs, and compare those with properties of multifilament polyamide tapes. Sample Population - 30 polyester tapes (width, 4 mm), 10 polyester tapes (width, 7 mm), and 30 polyamide tapes (width, 4 mm) were tested to failure. Cyclic loading experiments were also performed, using 3 polyester tapes of each width. Procedure - Tapes were mounted in a tensile tester as single loops, simulating intra-operative conditions, and elongated to failure at 1,000 mm/min. Additionally, the behavior of polyester tapes was tested at different elongation rates. In a second series of experiments, biomechanical variables of the polyester tapes were measured after 25 sets of 2,000 cycles between physiologic force limits. Results - Mean (± SD) ultimate loads of the 4-mm wide polyamide tapes, 4-mm wide polyester tapes, and 7-mm wide polyester tapes were 266.48 ± 13.19 301.78 ± 16.92, and 726.40 ± 3774 N, respectively. Corresponding stiffnesses were 15.57 ± 0.49, 21.63 ± 2.19, and 34.85 ± 2.66 N/mm, respectively. Failure properties of polyester tapes were affected by previous cyclic loading. Conclusions and Clinical Relevance - Polyester tapes of 4-or 7-mm widths should be able to resist forces resulting from weight bearing in dogs, suggesting that these tapes will be effective for stabilization of the stifle joint in dogs with a ruptured CCL.