Porcine tibia is a poor substitute for human cadaver tibia for evaluating interference screw fixation

Animal tissues are commonly used in anterior cruciate ligament graft fixation studies.

Porcine bones and tendons provide good surrogates for human cadaver tissues in the biomechanical evaluation of anterior cruciate ligament reconstruction.

Randomized experimental study.

Three different tissue models-pure porcine (porcine graft fixed in porcine tibia, group 1), combination (human hamstring graft and porcine tibia, group 2), and pure human (human graft and tibia, group 3)-were compared using both cyclic-loading and subsequent single-cycle load-to-failure tests to assess the effect of graft and bone tissue source (porcine vs human) on the fixation strength of anterior cruciate ligament reconstruction.

In the cyclic-loading test, the displacement (slippage) after 1500 cycles was 2.0 mm +/- 0.7 mm, 1.6 mm +/- 0.4 mm, and 4.4 mm +/- 1.9 mm for groups 1, 2, and 3, respectively (P <.001 between 1 and 2 vs 3). In the subsequent single-cycle load-to-failure test, the corresponding average yield loads were 668 N +/- 157 N, 962 N +/- 238 N, and 448 N +/- 98 N, all differences being statistically significant.

In comparison to young human cadaver tibia, porcine tibia underestimate graft slippage and overestimate the failure load of the soft tissue graft in anterior cruciate ligament reconstruction.

Porcine tibia does not provide a reasonable surrogate for human cadaver tibia for evaluating ACL reconstructions.