Ex vivo strength comparison of bioabsorbable tendon plates and bioabsorbable suture in a 3-loop pulley pattern for repair of transected flexor tendons from horse cadavers

Objective-To test the failure strength and energy of 2 bioabsorbable implants applied to transected deep digital flexor tendons (DDFT) from adult horses. Study Design-Ex vivo biornechanical experiment. Sample Population-Twelve pairs of deep digital flexor tendons harvested from the forelimbs of fresh equine cadavers. Methods-Poly-L-lactic acid tendon plates were custom manufactured for application to the cylindrical surface of an adult equine deep digital flexor tendon. Twelve pairs of DDFTs were transected 2 cm distal to the insertion of the distal check ligament of the deep digital flexor tendon. One tendon of each pair was randomly selected for repair with a biodegradable plate or a 3-loop pulley method. Size 2 polydioxanone suture was used in both repairs. Repairs were tested in tension to failure, with peak force (PF) and total energy (TE) at repair failure recorded in Newtons (N) and Joules (J), respectively. A paired t-test was used for statistical evaluation with a significant level set at P<.05. Results-Mean +/- SD PF for failure of plated tendons (1507.08 +/- 184.34N) was significantly greater than for sutured tendons (460.86 +/- 60.93 N). TE was also significantly greater for failure of plated tendons versus sutured tendons. Conclusions-Plate fixation of transected cadaver DDFTs appear to have superior immediate failure strength than 3-loop pulley repairs. Clinical Relevance-Whereas in vivo testing is required, a bioabsorbable tendon plate may provide initial increased strength to support tendon healing and decrease external coaptation requirements. (c) Copyright 2005 by The American College of Veterinary Surgeons