Mechanical properties of canine patella-ligament-tibia segment

To test the ex vivo mechanical properties of canine patella-ligament-tibia (PLT) segment and establish the relationship between donor size and PLT dimensions to the mechanical properties of PLT grafts.

Ex vivo mechanical testing study.

Canine PLT segments (n = 21 dogs; 42 PLT).

Morphometric measurements of PLT segments were taken from computed tomography (CT) images and compared with results obtained using calipers. PLT were tested to failure at a rate of 100% length/s. Mechanical properties and failure mode were recorded.

PLT width and thickness (P < .001 for both) measured by calipers were significantly lower than those taken from CT images. Thirty-five (83%) specimens failed by avulsion fracture from the patella, 1 failed mid-ligament, and 6 failed by tibial fracture. Dog weight and PLT length had the strongest Pearson's r value when correlated with load at failure (r = 0.73, 0.81, respectively).

Dog weight and PLT length were the best predictors of load at failure. PLT failure load of dogs weighing >25 kg were similar to those reported for the cranial cruciate ligament (CCL) suggesting that the PLT may be a suitable allograft for CCL replacement.