Accuracy of three pre- and intra-operative measurement techniques for osteotomy positioning in the tibial plateau levelling procedure.

OBJECTIVES: To prospectively compare the accuracy of three preoperative measurement techniques in tibial plateau levelling osteotomy (TPLO) planning.

METHODS: Fifty-nine dogs were randomly assigned to one of three measurement techniques; A, B or C. Surgeons measured the intended osteotomy location on preoperative radiographs according to the assigned technique. Measurements were used intra-operatively during osteotomy placement. Postoperative measurements were made by a single blinded observer and compared to preoperative measurements.

RESULTS: Fifty-one dogs were included for final statistical analysis. The mean absolute differences between pre- and postoperative measurements was 1.72 mm ± 0.958, 1.79 mm ± 1.010, and 3.56 mm ± 1.839, for techniques A, B and C, respectively. No significant differences were identified for patient age, gender, limb or surgeon. Techniques A and B were not significantly different (p = 0.8799). Techniques A and B were significantly more accurate than C (p = 0.0001 and p = 0.0003, respectively). Weight was significantly different among the groups (p = 0.047) but the statistical results did not change when an adjustment was made for bodyweight (p = 0.4971, p <0.001 and p = 0.0007, respectively).

CLINICAL SIGNIFICANCE: Preoperative measuring for planning a TPLO osteotomy is recommended. Techniques A and B in the current study were clinically practical and significantly more accurate compared to technique C.