ABSTRACT
OBJECTIVE: Rock-back is a reported complication following tibial plateau levelling osteotomy (TPLO), whereby tibial plateau angle (TPA) increases postoperatively. The mechanism of rock-back is not fully understood, although a recent ex vivo investigation demonstrated that osteotomy exit cut angle (ECA) and inclination of the plate in the sagittal plane might be risk factors. The purpose of this study was to explore these relationships in a clinical dog population. We hypothesized that dogs with rock-back would have a higher degree of plate inclination and downward ECA compared with those without rock-back. MATERIALS AND METHODS: Medical records and radiographs of dogs that underwent TPLO between January 2021 and January 2022 were retrospectively reviewed. TPA was recorded preoperatively, postoperatively, and at follow-up. Plate inclination, ECA, and descriptive data were collected. Observers measuring TPA were blinded to other variables. Rock-back was defined as a change in TPA ≥ 2. RESULTS: Ninety-five TPLO procedures met the inclusion criteria (n = 87 dogs). Rock-back was identified in 21% of TPLOs (n = 20/95). The mean increase in TPA in the rock-back group was 3.2 ± 2.6. Plate inclination and ECA were not correlated with the presence of rock-back. Descriptive variables did not have a significant correlation with rock-back. CONCLUSION: Plate inclination and ECA did not have a relationship with rock-back when defined as a postoperative TPA change ≥2 degrees, in this clinical retrospective study.
ABSTRACT
OBJECTIVE: To determine the influence of extreme brachycephalic conformation on presenting signs, imaging findings, intraoperative and perioperative complications following total ear canal ablation and lateral bulla osteotomy (TECA-LBO). STUDY DESIGN: Cross-sectional retrospective study. ANIMALS: A total of 306 (n = 242 dogs) TECA-LBOs (extreme brachycephalic breeds [EBB] = 81, other breeds [OB] = 225). METHODS: Medical records of patients undergoing TECA-LBO at a single referral institution (2010-2022) were evaluated. RESULTS: Extreme brachycephalic breeds most commonly presented acutely, at a younger age with oto-neurological signs (46/81, 56.8%). Chronic otitis externa without neurological signs (171/225, 76.0%) was most common in OBs. Extreme brachycephalic breeds preoperatively presented more frequently with facial nerve paresis (p = .001), vestibular syndrome (p = .001), and Horner's syndrome (p = .002) compared to OBs. On diagnostic imaging, bilateral changes (p = .038), aural masses (p = .045), para-aural abscesses (p = .011), otitis interna (p = .001), and brainstem changes (p = .001) were more common in EBBs. The apparent difference in intraoperative complication rate between EBBs (9/81, 11.1%) and OBs (12/225, 5.3%) did not reach statistical significance (p = .078). Perioperative complications occurred in 85/306 (27.8%) of TECA-LBOs with no difference in perioperative complication rate between EBBs (19/81, 23.5%) and OBs (66/225, 29.3%) (p = .586). CONCLUSION: Extreme brachycephalic breeds are more likely to present for TECA-LBO acutely, with neurological signs and more advanced diagnostic imaging abnormalities. Intra- and perioperative complication rates did not differ between EBBs and OBs. CLINICAL SIGNIFICANCE: Despite being subjectively more technically challenging, TECA-LBO did not result in more surgical complications in EBBs. Reported data are useful for effectively informing clients of the specific risks of TECA-LBO surgery.
