Effect of 9 mm tibial tuberosity advancement on cranial tibial translation in the canine cranial cruciate ligament-deficient stifle.

OBJECTIVE To assess the effect of 9 mm tibial tuberosity advancement (TTA) on cranial tibial translation (CTT) in a cranial cruciate ligament (CCL)-deficient canine stifle model. STUDY DESIGN In vitro cadaveric study. ANIMALS Canine pelvic limbs (n=12). METHODS Each stifle was placed in a jig at 135 degrees with a simulated quadriceps force and tibial axial force. CTT distance was measured with the CCL intact (iCCL), transected (tCCL), and after performing TTA using a 9 mm cage. RESULTS Mean CTT for iCCL was 0.42 mm, 1.58 mm after severing the CCL, and 1.06 mm post-TTA. The tCCL CTT measured without any quadriceps force was 2.59 mm. Differences between the intact and tCCL (P<.0001) and tCCL and TTA (P=.0003) were significant. The difference between the tCCL with and without the quadriceps force was not significant (P=.0597). CONCLUSIONS These data confirm that TTA does reduce CTT in tCCL stifles in this model. The CTT noted was less than that noted clinically. The addition of a simulated quadriceps force to a CCL-deficient stifle before a TTA, by itself, may not significantly lessen CTT. CLINICAL RELEVANCE Whereas this in vitro model demonstrated that TTA reduced CTT in canine stifles with CCL transected, the model limitations preclude extrapolation to the effect of TTA in a live dog.