Objectives: The purpose of this study was to evaluate risk factors for construct failure in dogs undergoing unilateral modified cranial closing wedge ostectomy for cranial cruciate ligament disease.
Materials and methods: Hospital and radiographic data were collected retrospectively. A sub-group for construct failure analysis was formed consisting of construct failure stifles and weight and plate matched control stifles. The following factors were assessed in relation to construct failure: plate size, plate position, proximal tibial flare, presence of adjunctive fixation and pre-operative and post-operative tibial plateau angle.
Results: One hundred and sixty-nine stifles were included within the overall data set, within which there was a major complication rate of 12% and a re-operation rate of 8%. There were 10 construct failure stifles and 52 weight and plate matched controls in the construct failure analysis. We found no difference between construct failure and weight and plate matched controls for plate position, proximal tibial flare, presence of adjunctive fixation and pre-operative or post-operative tibial plateau angle. Visual assessment of plate size relative to weight showed that consistently larger plates were used in comparison to those recommended for tibial plateau levelling osteotomy.
Clinical significance: The lack of significance in any variable between construct failures and weight and plate matched controls is likely a type II error. Despite this, when planning a cranial closing wedge ostectomy consideration should be given to plate size, plate position, shape of the proximal tibia and the use of adjunctive fixation.
