Effect of calcanean bone‐tunnel orientation for teno‐osseous repair in a canine common calcanean tendon avulsion model

Abstract

ObjectiveTo determine the influence of bone‐tunnel anchoring technique on teno‐osseous repair of the common calcanean tendon (CCT) in dogs.Study designRandomized, ex vivo, biomechanical.PopulationForty‐two skeletally mature canine hindlimbs.MethodsCanine hindlimbs were dissected to produce a model simulating avulsion of the CCT and accessory tendons from the calcaneus. Hindlimbs were randomized to 1 of 3 anchoring techniques (n = 14/group): a single transverse tunnel (TT), vertical tunnels (VT), or modified bone tunnels (MT) for teno‐osseous repair in a 3‐loop‐pulley (3LP) pattern using 0 USP polypropylene. Yield, peak and failure loads, construct stiffness, loads to produce a 3 mm teno‐osseous gap, and failure modes were compared between groups.ResultsThe only difference detected consisted of TT constructs yielding at loads 25% higher than MT constructs (P = .027).ConclusionAlthough yield loads were lower in MT constructs than other groups, the bone‐tunnel anchoring techniques tested here did not appear to influence the biomechanical properties or gapping characteristics of teno‐osseous repairs in this canine CCT avulsion model.Clinical significanceAll drilling techniques and bone‐tunnel orientations tested in the study reported here offer viable options to reattach the CCT to the calcaneus. Surgeons should evaluate how bone‐tunnel orientation may affect placement of adjunctive fixation methods to stabilize the talocrural joint after primary CCT repair in dogs.