Predicting tibial plateau angles following four different types of cranial closing wedge ostectomy.

OBJECTIVE: To investigate how tibial long axis (TLA) shift affects the postoperative tibial plateau angle (TPA) in four cranial closing wedge ostectomy (CCWO) techniques. STUDY DESIGN: In silico study. SAMPLE POPULATION: A total of 15 client-owned dogs. METHODS: Computed tomography (CT) scans of 15 client-owned dogs were reviewed using an open-source 3D computer graphics editor. Each computer-generated 3D tibia model underwent a CCWO, with cranial cortex alignment, in 10° increments up to 70° using each of the four previously described techniques. The TLA shift, TPA and mechanical tibial length (mTL) were calculated, using trigonometry, for each model. Equations for predicting final TPA were generated with linear regression. RESULTS: A total of 433 3D computer generated tibial models were analyzed. With each technique, the TPA varied in a linear fashion within the studied range of wedge angles. The TLA shift and tibial shortening magnitude varied between the four different CCWO techniques, with maximum mTL reduction of ranging from 7.5% to 40.9%. All predicted TPAs using the generated equations were within the target range of 4-6°. CONCLUSION: A linear relationship between ostectomy wedge angle and TPA correction was observed in this study, which allowed for generation of accurate corrective equations. CLINICAL SIGNIFICANCE: These results allow extrapolation of the wedge angle required to reach a postoperative TPA of 5°, by considering the TLA shift. The use of the generated corrective equations may thus increase CCWO planning precision.

Prophylactic use of a lidocaine constant rate infusion versus saline in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis: A randomized control trial.

OBJECTIVE: To evaluate the effect of a prophylactic lidocaine constant rate infusion (CRI) on the incidence and malignancy of catheter-induced ventricular ectopic complexes (VECs) during balloon valvuloplasty for management of pulmonic stenosis in dogs. STUDY DESIGN: Single-centre, prospective, randomized study. ANIMALS: Client-owned dogs (n = 70) with pulmonic stenosis. METHODS: Dogs were randomly assigned to one of two anaesthetic protocols: administration of lidocaine 2 mg kg-1 bolus followed by a CRI (50 µg kg-1 minute-1; group LD) or a saline placebo (group SL) during balloon valvuloplasty. All dogs were premedicated with methadone (0.3 mg kg-1) intramuscularly and a digital three-lead Holter monitor was applied. Anaesthetic co-induction was performed with administration of alfaxalone (2 mg kg-1) and diazepam (0.4 mg kg-1), and anaesthesia was maintained with isoflurane vaporised in 100% oxygen. CRIs were started on positioning of the dog in theatre and discontinued as the last vascular catheter was removed from the heart. All dogs recovered well and were discharged 24 hours postoperatively. Blinded Holter analysis was performed by an external veterinary cardiologist using commercially available dedicated analysis software; p < 0.05. RESULTS: Of the 70 dogs enrolled in the study, 61 were included in the final analysis: 31 in group LD and 30 in group SL. There was no significant difference between sinus beats (p = 0.227) or VECs (p = 0.519) between groups. In group LD, 19/31 (61.3%) dogs had a maximum ventricular rate ≥250 units and 20/30 (66.7%) dogs in group SL (p = 0.791). CONCLUSION AND CLINICAL RELEVANCE: In this study, the use of a prophylactic lidocaine bolus followed by CRI in dogs undergoing balloon valvuloplasty for management of pulmonic stenosis did not significantly decrease the incidence nor the malignancy of VECs during right heart catheterization compared with a saline CRI.

Design and topographic evaluation of a canine humeral anatomic plating system (CHAPS) for humeral condylar fracture repair in spaniels.

OBJECTIVE: To design a precontoured plating system for humeral condylar fracture repair in spaniels with humeral intracondylar fissure (HIF) and quantify accuracy of fit of the system on 3D printed bone models. STUDY DESIGN: Experimental on 3D printed models. METHODS: The plating system was based on morphometric data obtained from CT. Plates were applied to models and impression material was measured under the plates at points of interest to define plate bone gap (PBG). Data on locking screw interference on plate application were also obtained. RESULTS: Eleven elbows models were plated. Statistical analysis to assess for any difference in PBG measurements between left and right humuri revealed two loci (3 and 17) under the lateral plate and two loci (3 and 17) under the medial plate. On cumulate portion analysis, 67% of lateral plate loci and 80% of medial plate loci had a PBG of ≤2 mm respectively. An incidence of 2.1% (3/143) screw interference occurred. CONCLUSION: Design of a contoured plating system for application to humeral models from spaniels with HIF and its application with objective measurement of PBG is described. The majority of the loci measured under both lateral and medial plates had a BPG of ≤2 mm and the incidence of locking screw interference on plate application was low. CLINICAL SIGNIFICANCE: This novel system may have application for the stabilization of humeral condylar fractures in spaniels avoiding the need for plate contouring and minimizing the incidence of locking screw interference.