Effect of Calcaneal Bone Tunnel Orientation for Teno-osseous Repair in a Canine Common Calcaneal Tendon Avulsion Model

Introduction: Repair of canine common calcaneal tendon (CCT) avulsions is typically treated surgically, facilitated using a combination of sutures and bone tunnels. To date, the effect of calcaneal bone tunnel orientation and drilling technique on construct strength and teno-osseous gap formation has not been evaluated.

Objective: The aim of the study is to compare the biomechanical properties and gapping characteristics using three different drilling techniques and respective bone tunnel orientations to anchor the CCT to the calcaneus.

Materials and Methods: CCT were randomized to one-of-three drilling techniques (n = 14/group). Groups consisted of a single transverse tunnel (TT), vertical tunnels (VT), or modified bone tunnels (MT) for teno-osseous repair using a 3LP pattern in 0-USP polypropylene. Yield, peak and failure loads, construct stiffness, loads to produce a 3-mm teno-osseous gap, and failure modes were evaluated and compared between groups.

Results: Yield load differed between groups (p = 0.048). TT group had greater yield loads compared with the MT (p = 0.027), but not the VT group (p = 0.873). The TT, VT, and MT groups, however, did not differ regardless of bone tunnel orientation for peak loads (p = 0.535), failure loads (p = 0.500), construct stiffness (p = 0.685), loads to 3 mm gapping (p = 0.347), or failure mode (p = 0.602).

Discussion/Conclusion: Drilling technique and resultant bone tunnel orientation did not affect the biomechanical properties or gapping characteristics following teno-osseous repair. All drilling techniques represent a viable option for CCT re-attachment to the calcaneus. Intraoperatively, surgeons should evaluate how bone tunnel orientation may affect placement of adjunctive talocrural fixation methods in dogs.

Acknowledgements: There was no proprietary interest or funding provided for this project.

Publication History

Article published online:
26 October 2022