34th Annual Scientific Meeting proceedings

Objectives:

Cranial closing wedge ostectomy (CCWO) achieves dynamic stability in a cranial cruciate ligament deficient stifle by levelling the tibial plateau angle (TPA) to approximately 5-degrees. The aims of this study were: (1) to describe a CORA-based CCWO methodology (CCWO_CORA) and (2) to conduct an in-silico study to determine whether the CCWO_CORA achieves more accurate and repeatable post-operative TPA (TPA_POST) than methods described by Oxley et al. (CCWO_OX), Frederick and Cross (CCWO_FC) and Terreros and Daye (CCWO_TD).

Methods:

CT scans of six Labrador Retrievers, six German Shepherd dogs, six Rottweilers, and six small-breed dogs (<10kg) that were skeletally mature with normal tibiae were used for in silico planning and execution of the CCWO_CCWO, CCWO_OX, CCWO_FC and CCWO_TD techniques. Median TPA_POST (range) were reported and a Bayesian linear mixed-effects model was used to compare differences in TPA_POST between techniques.

Results:

The median TPA_POST for the CCWO_CORA method was 5.00º ((5.00-5.00º), coefficient of variation [CV] 0.0%).  Median TPA_POST was 6.40º ((5.37-7.04º), CV 7.0%)) for CCWO_OX, 3.32º ((2.53-5.24º), CV 23.8%)) for CORA_FC, and 7.44º ((6.85-9.42º), CV 10.0%) for CORA_TD. The difference in TPA_POST between methods was significant overall (p<0.0001), with post-hoc tests revealing TPA_POST for each method differed from all other methods (p<0.001).

Conclusions:

This study has described a CORA-based CCWO methodology which, unlike the other studied methods, always achieved the target TPA_POST of 5^o. CCWO_CORA methodology can be applied to a range of tibial morphologies and to a range of TPA_PRE with an entirely predictable TPA_POST.