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

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.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 <i>t</i>-tests.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.The suture anchor resisted gap formation more effectively than the bone tunnel and can be considered advantageous for gastrocnemius tendon reinsertion in cats.