Influence of muscle-sparing lateral thoracotomy on postoperative pain and lameness: A randomized clinical trial.

OBJECTIVE: To assess and compare the magnitude of lameness and level of pain after muscle-sparing lateral thoracotomy (MSLT) and standard lateral thoracotomy (SLT) in dogs. STUDY DESIGN: Randomized, blinded, prospective clinical study. ANIMALS: Twenty-eight client-owned dogs. METHODS: The latissimus dorsi muscle was retracted in the MSLT group and was transected in the SLT group. Gait was analyzed with a force plate, and the peak vertical force symmetry index (SI) was calculated within 24 hours before surgery, 3 days postoperatively, and 8 to 12 weeks postoperatively. Symmetry index and pain scores as measured by the Glasgow Composite Measure Pain Scale - Short Form were assessed as primary outcome measures. RESULTS: The SI 3 days postoperatively was lower compared with the preoperative SI value in all dogs, consistent with lameness of the ipsilateral thoracic limb (P < .001). The absolute differences in preoperative and 3-day-postoperative SI provided evidence that this change was 3.1-fold greater after SLT compared with after MSLT (P = .009). Pain scores 1 day after surgery were lower after MSLT (1) compared with after SLT (2.5, P < .001). CONCLUSION: Lateral thoracotomies caused postoperative pain and ipsilateral forelimb lameness, and both were reduced by sparing the latissimus dorsi. CLINICAL SIGNIFICANCE: Sparing the latissimus dorsi should be considered to decrease immediate postoperative morbidity in dogs undergoing lateral thoracotomy.

Radiological Evaluation of TATE Elbow Cartridge Position in Dogs.

OBJECTIVE: The main purpose of this study was to evaluate the effect of varying elbow flexion angle and elbow orientation on the radiological measurement of component position for first (1G) and second-generation (2G) TATE elbow cartridges, and to test intra/inter-observer variability of measurements. MATERIALS AND METHODS: A cadaveric thoracic limb was implanted with a 1G then 2G cartridge, and mounted in lateral recumbency on an acrylic platform. The platform was tilted by set increments up to 10° in both planes, and radiographs were performed at each angle before repeating with the limb in caudocranial positioning. A deterministic trigonometric model was used to show how component angles should vary with changes in orientation, and these were compared with those measured by two observers. Humeral component angle (HCA), radioulnar component angle, varus/valgus cartridge alignment angle and the cartridge height:isthmus width ratio (CIR) were evaluated. Angles within 5° of the zero degrees inclination angle and ratios within 0.2 of the zero degrees inclination ratio were defined as acceptable. RESULTS: Observer component angles for both cartridges were accurate and precise for inclinations up to 10° except for HCA during adduction/abduction. The CIR values were within the acceptable limit for inclinations up to 7.5° in both planes. CLINICAL SIGNIFICANCE: Acceptable limits of limb inclination during positioning for TATE elbow replacement cartridge assessment were defined. All component measurements were sufficiently accurate and precise to be considered for evaluation of component position in clinical cases.

Open-mouth jaw locking in cats: a literature review and use of CT in three cases.

CASE SERIES SUMMARY: This report summarises and reviews the published cases of open-mouth jaw locking in cats and describes three further cases. Case 1 was a 5-year-old, 5.3 kg male neutered domestic shorthair cat. CT identified changes consistent with temporomandibular joint (TMJ) dysplasia with osseous degenerative changes, and the cat subsequently underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. Case 2 was a 10-year-old, 6.0 kg male neutered Exotic Shorthair. Aside from a fracture of the left maxillary canine tooth crown and absence of the left maxillary fourth premolar tooth, no abnormalities were found on CT scan. The cat also underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. The third case was a 1-year-old, 4.0 kg male neutered Persian cat. Changes on CT were consistent with bilateral TMJ dysplasia, and the cat underwent staged bilateral partial zygomectomy with bilateral partial coronoidectomy. There was no recurrence of open-mouth jaw locking in any of the cases on long-term follow-up. RELEVANCE AND NOVEL INFORMATION: Open-mouth jaw locking has been reported in cats of a wide range of ages, from 1-10 years. Cats with all skull types (brachycephalic, mesaticephalic and dolichocephalic) may be affected, but brachycephalic breeds seem to be over-represented. A CT scan with the jaw locked in place is recommended for diagnosis and surgical planning purposes; two of the cases reported here document the first cases of TMJ dysplasia in cats to be definitively diagnosed using CT. Trauma and symphyseal or TMJ laxity may also predispose to development of the condition. Partial coronoidectomy and partial zygomatic arch resection performed alone or in combination are generally successful at preventing recurrence. Bilateral partial zygomectomy with bilateral partial coronoidectomy has not previously been reported as a surgical treatment, and is recommended when open-mouth jaw locking occurs bilaterally.