Radiographic Comparison of Virtual Surgical Corrective Options for Excessive Tibial Plateau Angle in the Dog.

OBJECTIVE: The main aim of this study is to compare the impact of six proximal tibial osteotomies on the geometry and alignment of tibias with and without excessive tibial plateau angle (TPA). STUDY DESIGN: Mediolateral radiographs of 30 canine tibias were divided into three groups (n = 10/group): moderate TPA (≤34 degrees), severe TPA (34.1-44 degrees) and extreme TPA (>44 degrees). Six proximal tibial osteotomies were simulated on each tibia using orthopaedic planning software: cranial closing wedge ostectomy (CCWO), modified CCWO (mCCWO), isosceles CCWO (iCCWO), neutral isosceles CCWO (niCCWO), tibial plateau levelling osteotomy with CCWO (TPLO/CCWO) and coplanar centre of rotation of angulation-based levelling osteotomy (coCBLO). All tibias were reduced to a standard target TPA. Pre- and postoperative measurements were obtained for each virtual correction. Compared outcome measures included tibial long axis shift (TLAS), cranial tibial tuberosity shift (cTTS), distal tibial tuberosity shift (dTTS), tibial shortening and osteotomy overlap. RESULTS: Across all TPA groups, TPLO/CCWO had the lowest mean TLAS (1.4 mm) and dTTS (6.8 mm); coCBLO had the largest TLAS (6.5 mm) and cTTS (13.1 mm); CCWO had the largest dTTS (29.5 mm). CCWO had the largest degree of tibial shortening of 6.5 mm, while mCCWO, niCCWO and coCBLO resulted in minimal tibial lengthening (1.8-3.0 mm). These trends were generally conserved across different TPA groups. All findings had a p-value less than 0.05. CONCLUSION: mCCWO balances moderate alterations to tibial geometry while preserving osteotomy overlap. The TPLO/CCWO has the least effect on tibial morphology alteration, whereas the coCBLO results in the largest alteration.

Case report: Fluoroscopic-assisted closed reduction and minimally invasive femoral capital physeal fracture repair in four calves.

Objective: To describe a minimally invasive osteosynthesis (MIO) femoral capital physeal fracture (FCPF) repair technique using multiple smooth Steinmann pins in four calves. Study design: Case series. Animal: Four calves (< 60 days of age). Methods: Medical records at a single referral hospital were searched for calves that had minimally invasive osteosynthesis (MIO) femoral capital physeal fracture (FCPF) repair performed using multiple Steinmann pins between 2020 and 2021. Calves receiving alternative repair, euthanasia without repair, or > 60 days of age were excluded. Medical records were reviewed together the following information: inciting FCPF cause, patient signalment, clinical sign duration pre-admission, history of dystocia, and any pre-admission treatment. Preoperative parameters collected included packed cell volume (PCV), serum total solids (TS), additional bloodwork when available, peripheral blood glucose, antimicrobial therapy, and analgesic medications. Preoperative coxofemoral radiographic images of all calves were obtained. Results/outcome: Four calves were presented with severe hind limb lameness from varying etiologies. FCPF was diagnosed in all calves via radiograph. All FCPFs were repaired with an MIO repair technique using multiple Steinmann pins. Intraoperative fracture reduction and fixation were deemed appropriate by the attending surgeon with the use of fluoroscopy. Postoperatively, all calves retained normal weight bearing and were ambulating. One calf died postoperatively due to an unrelated comorbidity (severe bronchopneumonia and hyperkalemia). The three remaining calves survived to hospital discharge and were ambulating normally with an adequate range of motion at the time of discharge. Long-term follow-up reports were available for two cases, which revealed long-term survival at 210- and 146-days. Owners reported good ambulation, and one of the calves was placed in the show ring and was performing. However, one calf was lost to long-term follow-up. Conclusion: MIO FCPF repair with multiple Steinmann pins, previously described in small animal species, can be implemented for FCPF repair in young calves. Clinical impact: This case series provides a foundation for minimally invasive osteosynthesis technique translation to large animal juveniles and reports an alternative MIO technique for capital physeal closed fracture repair in calves.

The development of ventricular fibrillation as a complication of pericardiectomy in 16 dogs.

OBJECTIVE: To describe the clinical characteristics, perioperative protocols, and outcomes in dogs diagnosed with ventricular fibrillation (VF) while undergoing pericardiectomy. STUDY DESIGN: Retrospective, multi-institutional study. ANIMALS: Sixteen client-owned dogs. METHODS: Cases were accrued through a listserve request posted to 3 subspecialty veterinary societies. Dogs were included if they developed VF during a pericardiectomy performed through an open or thoracoscopic approach. Data collected included signalment, history and physical examination, surgical approach, histopathology, treatment, and outcome. RESULTS: Indications for pericardiectomy included idiopathic chylothorax (n = 7), neoplasia (4), idiopathic pericardial effusion (4), and foreign body granuloma (1). Surgical approaches included thoracoscopy (12), intercostal thoracotomy (3) and median sternotomy (1). Electrosurgical devices were used to complete at least part of the pericardiectomy in 15 of 16 dogs. Ventricular fibrillation appeared to be initiated during electrosurgical use in 8/15 dogs. However, in 5/15 dogs it was not obviously associated with electrosurgical use. In 3/16 dogs the timing of initiation of VF was unclear. In 7/16 dogs, cardiac arrhythmias were noted prior to the development of VF. Fourteen of 16 dogs died from intraoperative VF. CONCLUSION: In most dogs ventricular fibrillation was a fatal complication of pericardiectomy. Ventricular fibrillation might be associated with the use of electrosurgical devices and cardiac manipulation during pericardiectomy although a causal link could not be established from the data in this study. CLINICAL SIGNIFICANCE: Surgeons must be aware of the risk of VF during pericardial surgery. Electrosurgery might need to be used judiciously during pericardiectomy, particularly in dogs exhibiting cardiac arrythmias.

Ex vivo mechanical testing of various suture patterns for use in tendon plating.

OBJECTIVE: To determine the influence of suture patterns on resistance to gap formation after tendon plating STUDY DESIGN: Ex vivo study SAMPLE POPULATION: Suspensory ligament and superficial and deep digital flexor tendons harvested from 16 neonatal cadaver foal limbs. METHODS: Each tendon/ligament from a given limb was randomly assigned to one of three treatment groups consisting of a 7-hole veterinary cuttable plate fixed with alternating simple interrupted, figure-8, or hybrid suture patterns. The constructs were distracted at a rate of 1.0 mm/s to failure, as determined by the formation of a 1 mm gap for initial failure and a 3 mm gap for ultimate failure. The mode of failure was also recorded. RESULTS: Constructs prepared with hybrid and figure-8 patterns sustained over 2× higher (p < .01) forces before gap formation compared to those prepared with a simple interrupted pattern. No difference was identified between tendons whose plate was secured with hybrid or figure-8 suture patterns. Mode of failure between groups did not differ. CONCLUSION: The figure-8 and hybrid patterns described herein improved the resistance to gap formation of plated tendons compared to an alternating simple interrupted pattern described previously. CLINICAL SIGNIFICANCE: Figure-8 and hybrid patterns should be considered over simple interrupted patterns to improve resistance to gap formation in horses undergoing tendon plating.

Short-term outcomes of 59 dogs treated for ilial body fractures with locking or non-locking plates.

OBJECTIVE: To determine the influence of plating systems on the clinical outcomes in dogs treated for ilial fractures. DESIGN: Retrospective study. ANIMALS: Fifty-nine dogs (63 hemipelves). METHODS: Radiographs and medical records of dogs with ilial fractures presented to Iowa State University between 2003 and 2019 were reviewed. After fracture reduction, fractures were fixed with a locking plate system (LPS) or non-locking plate system (NLS). Perioperative, long-term complications, and follow-up data were recorded. The frequency of implant failure and pelvic collapse were compared using a logistic and linear regression analysis, respectively. Where the univariate test was statistically significant, a multivariate analysis across categories was performed to identify statistically different categories. RESULTS: LPS and NLS implants were used in 25/63 and 38/63 hemipelves, respectively. Median follow-up time was 8 weeks (3-624 weeks). Implant failure occurred in 18/63 (29%) of fracture repairs, consisting of 17 with NLS and 1 with LPS. Revision surgery was recommended in five cases of implant failure, all with NLS. The probability of implant failure was higher when fractures were fixed with NLS (p = .0056). All other variables evaluated did not seem to influence outcome measures. CONCLUSION: The variable with the most influence on the outcomes of dogs treated for ilial fractures consisted of the fixation method (NLS vs. LPS). Fractures repaired with NLS were nearly 20 times more likely to fail than those repaired with LPS. CLINICAL RELEVANCE: Surgeons should consider repairing ilial body fractures in dogs with LPS to reduce the risk of short-term implant failure.

Radiation exposure associated with percutaneous fluoroscopically guided lag screw fixation for sacroiliac luxation in dogs.

OBJECTIVE: To determine radiation exposure to surgical personnel and to evaluate the accuracy of a modified percutaneous lag screw fixation technique for sacroiliac luxation (SIL) under fluoroscopic guidance in dogs. STUDY DESIGN: Cadaveric experimental study. SAMPLE POPULATION: Seventeen beagle cadavers with iatrogenic SIL. METHODS: Seventeen beagles with iatrogenic SIL underwent reduction and stabilization with 3.5-mm screws. Hypodermic needles (14 gauge) and fluoroscopy were used to orient two Kirschner wires for temporary stabilization and to guide drilling of glide and pilot holes using cannulated drill bits. Duration of surgery and radiation exposure were recorded. Postoperative computed tomographic evaluation of screw position and angulation was performed. RESULTS: Average time for fixation was 15.85 minutes (range, 6.37-33.5). Cumulative radiation doses of 0.4 mrem for the dominant arm of the assistant and 0 mrem for the primary surgeon were recorded. The mean dorsoventral and craniocaudal screw angles were 0.68° ± 3.4° (range - 5.4° to 9.5°) and 1.9° ± 3.2° (range - 4.3° to 9.1°), respectively. Sixteen of the 17 dogs had 100% sacral screw purchase, with the remaining case achieving 93.4% purchase. CONCLUSION: Fluoroscopy-assisted percutaneous placement of 3.5-mm cortical screws in lag fashion performed with 14-gauge needles in conjunction with Kirschner wires and cannulated drill bits yielded repeatable accurate screw placement with low levels of ionizing radiation exposure to the surgical team. CLINICAL SIGNIFICANCE: The described technique may be a viable method for minimally invasive osteosynthesis fixation of SIL with low levels of radiation exposure to the surgical team. These results provide evidence to support further evaluation of radiation exposure in clinical cases and can aid in study design and sample size determination.

Upper Airway Obstruction Due to Primary Laryngeal Blastomycosis in a Dog.

A 9 yr old female spayed Labrador retriever presented for progressive dyspnea. Inspiratory stridor and inspiratory and expiratory dyspnea were present, consistent with an upper airway obstruction. A laryngeal exam revealed severe thickening of the arytenoid cartilages and masses associated with the arytenoids. A tracheostomy tube was placed, and the masses were biopsied. Histopathology showed pyogranulomatous inflammation secondary to Blastomyces dermatitidis. The dog was initially treated with amphotericin B and terbinafine in the hospital until the airway obstruction resolved and the tracheostomy tube could be removed. The dog experienced complete recovery after long-term treatment with itraconazole and terbinafine. This is the first report of laryngeal obstruction secondary to primary laryngeal blastomycosis in a dog. Blastomycosis should be considered for cases of obstructive laryngeal disease, and a good outcome can be achieved with antifungal treatment.

Laparoscopic treatment of ovarian remnant syndrome in dogs and cats: 7 cases (2010-2013).

OBJECTIVE: To describe the technique and evaluate the outcome of laparoscopic treatment of ovarian remnant syndrome (ORS) in dogs and cats. DESIGN: Retrospective case series. ANIMALS: 7 client-owned dogs and cats. PROCEDURES: Medical records of dogs and cats with ORS that were treated laparoscopically at 3 large veterinary teaching hospitals were reviewed. Laparoscopic ovarian remnant resection was performed by means of either a 3-port or single-port technique with the patient in dorsal recumbency. The area caudal to both kidneys was thoroughly inspected for evidence of ovarian tissue by tilting the patient laterally. Any ovarian remnant tissue in these areas was resected with a bipolar vessel sealer. RESULTS: 5 female dogs and 2 female cats that had previously undergone ovariectomy or ovariohysterectomy were included in the study. Six procedures were performed with a standard 3-port technique, and 1 was performed with a single-port technique. Median surgery time was 90 minutes (range, 50 to 150 minutes). No patient required conversion to laparotomy. Six of the 7 patients had complete resolution of clinical signs after surgery. One patient underwent laparotomy 7 weeks after surgery for management of stump pyometra, but no further ovarian tissue was detected. CONCLUSIONS AND CLINICAL RELEVANCE: Laparoscopic management of ORS in this cohort of dogs and cats was associated with minimal morbidity. Laparoscopic treatment of ORS in dogs and cats may be recommended for appropriately selected patients.