Biomechanical analysis of suture anchors and suture materials in the canine femur

Objective— Biomechanical analysis of acute load to failure (ALF) of 3 veterinary and 1 human suture anchor and cyclic load to failure with two suture material/suture anchor constructs in canine femoral condyles.
Study Design— Biomechanical in vitro study.
Sample Population— Cadaveric femora from 20–30 kg dogs.
Methods— Three veterinary and 1 human suture anchor were placed in the cranial and caudal aspects of the femoral condyle and subjected to 0° ALF. Anchors were loaded with 5 USP Fiberwire or 27 kg test nylon leader line (NLL) and subjected to 90° cyclic testing for 10,000 cycles followed by ALF at 90°.
Results— No significant difference in ALF for any anchor type was detected in the cranial aspect of the femoral condyle; however all veterinary anchors had higher ALF in the caudal aspect of the femoral condyle. In cyclic testing, the constructs in descending order (most cycles to least) were: (1) FlexiTwist/NLL, (2) Securos/Fiberwire, Securos/NLL, (3) IMEX/Fiberwire, IMEX/NLL, and (4) FlexiTwist/Fiberwire, Fastin/Fiberwire. Fiberwire was significantly stronger than NLL in post-cycling ALF testing.
Conclusions— Veterinary anchors had higher ALF in the caudal versus cranial aspect of the femoral condyle. Except for the FlexiTwist in which NLL performed better, Fiberwire and NLL both had similar cyclic performance with each veterinary anchor type. The veterinary anchors exceeded the human anchor in ALF and cycles to failure.
Clinical Relevance— The tested veterinary suture anchors with Fiberwire or NLL may be used in the femoral condyle, preferably in the caudal aspect, and should withstand estimated loading conditions in appropriately confined postoperative canine patients.