Summary
Objectives: To determine whether the medial collateral ligament can be a reliable intra-operative anatomical landmark for rotation of the tibial plateau in the tibial plateau levelling osteotomy (TPLO) procedure, thus providing a tibial plateau rotation equal to that obtained using standard preoperative measurements.
Methods: Tibial plateau levelling osteotomy procedures were performed on pelvic limbs (n = 42) from canine cadavers with or without a history of cranial cruciate ligament deficiency. The rotation of the proximal fragment was performed such that the orientation of the fibres of the medial collateral ligament were aligned parallel to the caudal tibial cortex at the location of the osteotomy. Statistical analysis was performed to evaluate the difference between calculated rotation to achieve a postoperative tibial plateau angle of five degrees and the actual rotation achieved by aligning the medial collateral ligament and caudal tibial cortex.
Results: The rotation performed by alignment of the medial collateral ligament fibres with the caudal tibial cortex resulted in a significantly greater rotation than the calculated movement required to achieve a postoperative angle of five degrees. The mean over-rotation was 2.1 ± 1.73 mm.
Clinical significance: Use of the medial collateral ligament alignment with the caudal tibial cortex will reliably result in over-rotation of the tibial plateau and should not be used as an intra-operative guideline for tibial plateau rotation during TPLO procedures.
Keywords
TPLO - tibial plateau levelling osteotomy - tibial plateau angle - medial collateral ligament
