Small animal surgery resident Cornell University Ithaca, New York
Preoperative and intraoperative planning increases the likelihood of achieving a centered osteotomy during TPLO. The objective of this study was to determine the accuracy of translation of preoperative TPLO planning measurements to intra-operative tibial landmarks. We hypothesized that accurate translation of planning landmarks to intra-operative landmarks will be inconsistent. Routine approaches to the proximal tibia (n=40 cadaveric limbs) were performed followed by radio-opaque marking of the MCL, the tibial tuberosity, attachment of the patellar ligament, and the palpable craniomedial proximal tibial depression (CPD). Orthogonal radiographs were obtained, preoperative measurements for TPLO were performed, followed by routine TPLO using these measurements. Stifles were re-radiographed to determine the difference between radiographic planning and executed TPLO. All data is presented as mean (standard deviation). The MCL was directly centered over the ICE (intercondylar eminence) in 50% of canine stifles; the other 50% were 1.9 (2.5) mm caudal to the ICE. There was no significant difference between the planned and executed D1 measurement (0.25 (2.5) mm; p=0.42), however, there were significant differences between these for D2 and D3 (0.72 (2.4) mm, p=0.02; 0.94 (2.8) mm, p=0.01 respectively). The optimal planned osteotomy exited the tibial plateau 1.9 (1.6) mm cranial to the CPD. Limitations of this study include a single observer obtaining all measurements to limit variability. Use of the MCL, D2, and D3 are not accurate for osteotomy planning in this model but this may not be clinically relevant.
