Gap Formation in Achilles Tendon Reinsertion in Cats: A Comparative Ex Vivo Study of Bone Tunnel and a Bioabsorbable Suture Anchor

Abstract

Objective This study aimed to compare gap formation between a classical transcalcaneal bone tunnel and a bioabsorbable suture anchor in a feline Achilles tendon avulsion model. Study Design Gastrocnemius tendons were dissected from the calcaneus of seven pairs of feline gastrocnemius tendon-calcaneus specimens. Reinsertion was performed either through a transverse bone tunnel or with a bioabsorbable suture anchor with a metric 3 non-absorbable monofilament polypropylene-polyethylene suture in a Bunnell-Mayer pattern. Tensile tests were conducted under physiological loading conditions. Gap formation was tracked with a video camera, and force on the tendon was measured. Results were compared with t -tests. Results Mean load at a gap of 0.5 mm was significantly higher for the suture anchor (44.2 ± 5.5 N) compared with the bone tunnel (23.0 ± 15.4 N). A 3-mm gap was not reached with the suture anchor. Failure loads were dominated by suture breakage and were not significantly different between suture anchor (55.2 ± 8.0 N) and bone tunnel (65.1 ± 8.3 N). Pulling through the tendon substance did not occur. Conclusion The suture anchor resisted gap formation more effectively than the bone tunnel and can be considered advantageous for gastrocnemius tendon reinsertion in cats.