Comparison of long-term functional outcome of tibial plateau leveling osteotomy versus extracapsular fixation in a heterogeneous population of dogs using force-plate gait analysis and survival analysis -- preliminary results

Abstract

A long-term comparison of the functional outcome of tibial plateau leveling osteotomy (TPLO) and extracapsular fixation (ECF) using ground reaction forces is presented. The working hypothesis was that a dog with a TPLO would exhibit a more rapid, complete return to normal function than one with ECF. Thirty dogs with unilateral CCL rupture (15 TPLO, 15 ECF) and 72 clinically normal dogs were evaluated. Affected dogs were treated with either TPLO or ECF based on surgeon and owner preference. Dual force-plate gait analysis was performed on all normal dogs to establish a normal gait profile of ground reaction forces for a heterogenesou population. Limb function in the affected dogs was measured with dual force-place gait analysis before surgery, then post-operatively at 1 day, 2 days, 2 weeks, 8 weeks, 6 months, and 1 year. Kaplan-Meir survival analysis was performed to determine the proportion of dogs returning to normal function for treatment comparisons. No significant difference was found between TPLO and ECF in time to and completeness of recovery (p>0.1 for peak vertical force, vertical impulse, and contact time.) Dogs treated with TPLO an ECF achieve normal limb loading. In the long-term no benefit of one treatment over the other is apparent with the current dataset.