The use of lateral arthroscopy portals for the management of a fragmented lateral coronoid process in an English Bulldog.

OBJECTIVE: To report a case of unilateral lateral coronoid process fragmentation in a dog treated via lateral elbow arthroscopy portals. ANIMAL: A 9-month old male intact English Bulldog. STUDY DESIGN: Case report. METHODS: The dog presented with a history of intermittent right thoracic limb lameness. Orthopedic examination on presentation was unremarkable. Computed tomography of the right thoracic limb was pursued and revealed a mineralized focus along the lateral margin of the lateral coronoid process as well as sclerosis of the medial coronoid process and subtrochlear region of the ulna. Elbow arthroscopy was performed via a lateral approach and revealed chondromalacia of the entire lateral coronoid process. Abrasion arthroplasty of the lateral coronoid process was performed. RESULTS: Complete resolution of the lameness was achieved within two weeks of surgery. At 6 weeks postoperatively, the dog remained sound and a gradual return to normal activity was recommended. At the final follow up assessment, 5 months after surgery, no abnormalities were found on orthopedic examination and the owners reported excellent limb function with no observable lameness. CONCLUSION: Lateral coronoid disease can occur as a rare component of elbow dysplasia in dogs. Abrasion arthroplasty via lateral arthroscopic portals may have resulted in a successful outcome in this case and may form an effective treatment option for lateral coronoid disease in dogs.

Prospective evaluation of lymphatic embolization as part of the treatment in dogs with presumptive idiopathic chylothorax.

OBJECTIVE: To describe the embolization technique and short-term clinical outcome in dogs undergoing lymphatic embolization (LE) as part of treatment for presumptive idiopathic chylothorax (IC). Additionally, to document findings in computed tomography lymphangiography (CTLa) following embolization. STUDY DESIGN: Prospective case series. ANIMALS: Eight client-owned dogs. METHODS: Dogs underwent CTLa followed by thoracic duct ligation (TDL), pericardiectomy (PC) and LE. A mixture of 3:1 lipiodol: n-butyl cyanoacrylate embolic solution was injected through a catheterized mesenteric lymphatic vessel via limited abdominal approach using intraoperative fluoroscopy. CTLa was scheduled for 12 weeks postoperatively, and long-term follow-up was obtained via telephone contact. RESULTS: LE was technically successful in six of the eight dogs; and clinically successful in five of the six dogs. In the unsuccessful dog, a diagnosis of lymphangiosarcoma was determined, and the owners elected for euthanasia. Five dogs who underwent successful LE underwent CTLa at 12 weeks. Complete resolution of pleural effusion occurred in three dogs and scant pleural effusion in two dogs. A robust lymphatic embolus preventing antegrade continuation of radiocontrast was documented in all five dogs. Five of the six dogs that underwent LE, were alive and clinically normal at 358-960 days postoperatively. CONCLUSIONS: LE is a feasible part of treatment for dogs with IC. Additionally, a robust lymphatic embolus and lack of radiocontrast flow past the embolus was documented at 12 weeks following surgery. CLINICAL SIGNIFICANCE: LE has the potential to reduce surgical failure by reducing efferent lymphatic chyle flow, occluding missed lymphatic branches and preventing the development of collateral branches.

The use of lateral arthroscopy portals for the management of bilateral osteochondritis dissecans of the radial head in an English bulldog.

OBJECTIVE: To report a case of bilateral radial head osteochondritis dissecans (OCD) in a dog treated via lateral elbow arthroscopy portals. STUDY DESIGN: Case report. ANIMALS: Six month old female spayed English bulldog. METHODS: The dog was presented for a left thoracic limb lameness localized to the elbow. Computed tomography revealed bilaterally symmetrical mineralized fragments in the lateral compartment of the elbow joint and blunting of the medial coronoid processes. The fragments were associated with a thin donation bed along the caudolateral articular surface of the radial head with moderate surrounding subchondral bone sclerosis. Bilateral elbow arthroscopy was pursued. Arthroscopy was initiated via a standard medial approach, which allowed for abrasion arthroplasty of the radial incisure and medial coronoid process but provided insufficient access to the radial head lesions. A lateral arthroscopic approach was subsequently performed and provided excellent access to the radial head for fragment retrieval and abrasion arthroplasty. RESULTS: Histopathology of the radial head fragments revealed mild cartilage degeneration and retention of cartilaginous cores within subchondral bone, consistent with OCD. Complete resolution of lameness and elbow pain were observed on clinical examination 5 months postoperatively. CONCLUSION: Radial head OCD can occur as a rare component of elbow dysplasia in growing dogs, and fragment retrieval with abrasion arthroplasty via lateral arthroscopic portals may be an effective treatment option.

Anatomic and volumetric characterization of the cisterna chyli using CT lymphangiography and computer-assisted design software in dogs with idiopathic chylothorax.

The objectives of this retrospective, observational study were to characterize the anatomical features of the cisterna chyli (CC) in a cohort of dogs diagnosed with idiopathic chylothorax that underwent CT lymphangiography (CTLa), and to evaluate the feasibility of computer-assisted design (CAD) software to quantify volumetric measurements of the CC. Twenty-three client-owned dogs with idiopathic chylothorax were included. Additionally, CTLa was performed in three canine cadavers to assess the ability of CAD software to accurately acquire volumetric measurements. Injection sites, attenuation values, anatomic location, dimensions, and aortic diameter to CC ratio (Ao:CC) were recorded. Video records of video-assisted thoracic surgery (VATS) thoracic duct ligation (TDL) were reviewed in eight out of 23 dogs to compare operative and CTLa findings. The CC was dorsal and right-sided in 18 out of 23 dogs, located between L1 and L4 in 21 dogs, and extended as far cranially as T11 in two dogs. The median measurements for length, height, and width were 150.0, 5.5, and 13.3 mm, respectively. Median total volume was 1.82 mL. Median volumes to the right and left of the aorta were 1.46 and 0.49 mL, respectively (P = .014). Median total CC volume to body weight ratio (CC:bw) was 0.07 mL/kg. The presence of an intrathoracic CC was observed intraoperatively in six out of eight cases that underwent VATS TDL. Findings supported the use of CTLa and CAD as feasible methods for characterizing the CC in dogs diagnosed with chylothorax. These methods may facilitate interventional planning involving the CC such as embolization.

Survey of instructor and student impressions of a high-fidelity model in canine ovariohysterectomy surgical training.

OBJECTIVE: To evaluate the usefulness of a high-fidelity model for teaching ovariohysterectomy (OHE) to veterinary students. STUDY DESIGN: Longitudinal survey. SAMPLE POPULATION: Clinicians with ≥2 years postgraduate experience in small animal surgery and a sophomore veterinary student population at 1 institution. METHODS: Twelve clinicians evaluated the high-fidelity model for realism. Questionnaires were distributed to sophomore veterinary students prior to and after OHE training on the high-fidelity model (SynDaver Surgical Canine) and after performing OHE as primary surgeon with a live dog. Time for students to perform OHE (identify the first ovarian pedicle to transecting the uterine body) and number of technical errors (visceral injury, hemorrhage, loose ligatures) were compared between the model and live dog groups. RESULTS: Evaluators rated the high-fidelity model as moderate-to-highly realistic. Students' confidence improved after practicing on the model in all critical steps and additionally improved after performing an OHE on a live dog. Time to complete the OHE on the model (mean ± SD,73.4 ± 27.1 minutes) and live dogs (83.0 ± 24.7 minutes) did not differ (P = .20). Frequency of hemorrhagic events (P = .77) and accidental visceral injury (P = .30) did not differ between the model and live dogs. However, fewer loose ligatures were placed in live dogs (23/64) compared with the model (22/37; P = .02). CONCLUSION: The high-fidelity model improved the confidence of sophomore students. The duration of OHE did not differ between the model and live dogs. CLINICAL IMPACT: The high-fidelity model is valuable for improving confidence in veterinary students prior to live-dog OHE.

Comparison of iatrogenic articular cartilage injury in canine stifle arthroscopy versus medial parapatellar mini-arthrotomy in a cadaveric model.

OBJECTIVE: To assess iatrogenic articular cartilage injury (IACI) resulting from arthroscopy versus medial parapatellar mini-arthrotomy of the stifle. STUDY DESIGN: Paired comparison of canine cadaver stifles treated with arthroscopy or mini-arthrotomy ANIMALS: Paired canine stifles from 14 cadavers (≥20 kg). METHODS: Stifles (N = 28) were assigned to arthroscopy or arthrotomy. Full stifle joint exploration and meniscal probing were performed. Joints were disarticulated and India ink assay performed. IACI was defined as sharply delineated lesions with India ink uptake. Incidence, number, and lesion area in defects articular cartilage, incision length, surgery duration, and joint structures visualized were recorded. RESULTS: Arthroscopy resulted in greater IACI than mini-arthrotomy, including incidence of IACI (arthroscopy: 13 stifles, mini-arthrotomy: 4 stifles; P = .009), number of IACI per stifle (arthroscopy: 3.4 ± 2.90, mini-arthrotomy: 0.9 ± 1.96; P = .04), and IACI area (arthroscopy: 5.9 ± 7.58 mm2 , mini-arthrotomy: 1.7 ± 4.50 mm2 ; P = .003). Incision length was shorter with arthroscopy (1.0 ± 0.38 cm) versus mini-arthrotomy (5.3 ± 0.61 cm; P < .0001). Surgical duration was not significantly different between groups (arthroscopy: 12.5 ± 3.49 minutes, mini-arthrotomy: 11.05 ± 1.60 minutes; P = .21). Visualization of articular structures was incomplete in 14/14 mini-arthrotomy stifles and 1/14 arthroscopy stifles (P < .001). CONCLUSION: Incidence, number, and area of IACI were greater in the arthroscopy group versus the mini-arthrotomy group. Mini-arthrotomy resulted in a longer incision and incomplete joint visualization. Methods of preventing IACI and clinical significance of IACI warrant further investigation.

Radiation exposure to the orthopedic surgeon-a dosimetric comparison of two mini C-arm fluoroscopy models: a pilot study.

OBJECTIVE: Perform a cadaveric experimental pilot study to measure and compare potential radiation exposure to an orthopedic surgeon from 2 different-generation mini C-arm models during a simulated orthopedic surgery. SAMPLE: 16 radiation dosimeters. METHODS: Mock surgery setups were constructed with a canine cadaver thoracic limb and 2 different-generation mini C-arm models. Four radiation dosimeters were placed near the mini C-arm to mimic common locations of radiation exposure during image acquisition. One mini C-arm was placed in auto technique mode, and 100 static images were acquired. The dosimeters were replaced, and a 5-minute-long dynamic image was acquired. The same protocols were repeated for the second mini C-arm. The dosimetry badges were then submitted for radiation exposure quantification. RESULTS: All but 1 dosimeter had radiation exposure levels below the detectable limits of the dosimeter. The dosimeter closest to the primary x-ray beam of 1 mini C-arm during dynamic image acquisition had a reading of 1 mrem. CLINICAL RELEVANCE: Intraoperative radiation exposure from the mini C-arm is low, specifically to areas not protected by lead and in close proximity to the primary x-ray beam. That being said, surgeons should always practice the principles of ALARA (ie, as low as reasonably achievable) to minimize radiation exposure in the workplace.

Use of a hybrid external skeletal fixator construct for managing tibial tuberosity avulsion fractures in three dogs.

CASE DESCRIPTION: 3 juvenile (4 to 5 months of age) medium- to large-breed or crossbred dogs were evaluated for sudden unilateral non-weight-bearing lameness in a pelvic limb after a fall during strenuous activity. CLINICAL FINDINGS: All dogs had non-weight-bearing lameness (n = 2) or bore minimal weight (1) on the affected pelvic limb, had soft tissue swelling over the cranial aspect of the stifle joint in the affected limb, seemed to resist manipulation of the affected joint, and had tibial tuberosity avulsion fracture confirmed with radiography. TREATMENT AND OUTCOME: Each dog underwent surgical fracture reduction and stabilization with a hybrid circular-linear external skeletal fixator construct with interfragmentary Kirschner wires used to stabilize the avulsed tibial tuberosity. Successful fracture reduction and stabilization were achieved, and only minor postoperative complications occurred. Construct removal 2 weeks postoperatively resulted in no displacement of the tibial tuberosity in 2 dogs and only minor proximal displacement in the remaining dog, allowed for continued unencumbered growth through the apophysis and proximal tibial epiphysis in all dogs, and did not result in tibial conformational anomalies. Clinical outcome was considered excellent in 2 dogs with complete resolution of lameness and good in 1 dog with subsequent occasional mild lameness. CLINICAL RELEVANCE: Our findings suggested that the described hybrid external skeletal fixator construct could be used as a minimally invasive strategy to successfully manage tibial tuberosity avulsion fractures in dogs and may be advantageous in very young medium- to large-breed dogs in which premature closure of the tibial tuberosity apophysis could result in distal translocation of the tibial tuberosity and deformity of the tibial plateau.

Biomechanical Comparison of Three Stabilization Methods for Tibial Tuberosity Fractures in Dogs: A Cadaveric Study.

OBJECTIVE: The aim of this study was to compare the biomechanical properties of a hybrid external skeletal fixator (HESF) construct to the placement of paired interfragmentary Kirschner wires alone, and pin and tension band wire (PTBW) fixation for the stabilization of simulated tibial tuberosity fractures in dogs. STUDY DESIGN: Tibias were harvested from 12 skeletally mature dog cadavers weighing 20 to 30 kg. An osteotomy was made through the base of the tibial tuberosity, which was subsequently repaired with either paired Kirschner wires, PTBW fixation or a HESF. A tensile load was applied to the tibial tuberosity until failure occurred. Mode of failure was described and biomechanical parameters obtained were compared between fixation groups. RESULTS: The PTBW fixation and HESF construct afforded greater stiffness and load at 3 mm of axial displacement compared with fixation with Kirschner wires alone. There was no significant difference in stiffness and load at 3 mm displacement between PTBW and HESF fixation. Failure occurred by bending and pullout of the Kirschner wires for all fixation groups, preceded by untwisting of the knot in PTBW specimens. CONCLUSION: The HESF may provide a favourable alternative to PTBW fixation for tibial tuberosity avulsion fracture stabilization in dogs with substantial remaining growth potential.

Use of combined transarticular pinning and external skeletal fixation for the reduction and stabilization of multiple metatarsophalangeal luxations in a cat.

CASE SUMMARY: A 1-year-old spayed female domestic shorthair cat presented for evaluation of a non-weight bearing right pelvic limb lameness after falling from a 4 m height. On orthopedic examination there was substantial swelling and pain on manipulation of the right pes. Radiographs were obtained under sedation, and these revealed dorsoproximal luxations of the third, fourth and fifth metatarsophalangeal joints, and lateral rotation of the second digit. Closed manual reduction under sedation was unsuccessful and open reduction under general anesthesia was therefore performed. Combined transarticular pinning and external skeletal fixation were performed to maintain reduction of the third and fourth digits. Marked postoperative swelling of the distal pes and internal rotation of the third and fourth digits were noted within 24 h of surgery. Three weeks postoperatively, the cat had a persistent weight bearing right pelvic limb lameness and minor pin tract inflammation. All implants were removed and the limb was splinted for 1 week. Internal rotation and pin tract inflammation had resolved at the time of splint removal, and the lameness resolved within 6 weeks of surgery. The cat was not lame, but radiographs revealed mild-to-moderate degenerative osteoarthrosis when the cat was evaluated 6 months after surgery. RELEVANCE AND NOVEL INFORMATION: There are limited reports describing metatarsophalangeal luxations in cats. Although several surgical techniques have been advocated, specific outcomes in clinical cases have not been reported. This report describes the clinical application and outcome of combined transarticular pinning and external skeletal fixation for the management of multiple metatarsophalangeal luxations in a cat.

Comparative Analysis of Vertical Forces in Dogs Affected with Cranial Cruciate Ligament Disease and Tibial Plateau Angles Greater or Less than 25 Degrees.

OBJECTIVE: Our objective was to compare the peak vertical force (PVF) and vertical impulse (VI) between dogs with cranial cruciate ligament disease and a tibial plateau angle (TPA) greater or less than 25 degrees. METHODS: A retrospective study was performed in 18 dogs with cranial cruciate ligament disease in which kinetic gait data were obtained with a pressure walkway system. Dogs were distributed in two groups: dogs with a TPA ≤ 25 degrees (n = 8) and dogs with a TPA > 25 degrees (n = 10). Mean PVF and VI in per cent of body weight (%BW) were compared between groups with an unpaired t-test (p < 0.05). RESULTS: Mean PVF and VI for the cranial cruciate ligament disease limb were 14.39%BW and 3.57%BWs for dogs with a TPA >25 degrees and 14.44%BW and 3.47%BWs for dogs with a TPA ≤ 25 degrees. There was no significant difference in mean PVF and VI between the groups. CONCLUSION: The results suggest that there is no difference in kinetic data between dogs with cranial cruciate ligament disease and a TPA greater or less than 25 degrees. Other factors such as body weight, time of injury or meniscal lesion could be more related to the magnitude of cranial cruciate ligament disease lameness.

Feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation of clinically normal canine ovaries.

OBJECTIVE: To determine the optimal energy profile for and to assess the feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation (MWA) of clinically normal canine ovaries. SAMPLE: 44 extirpated ovaries from 22 healthy dogs. PROCEDURES: In the first of 2 trials, 13 dogs underwent oophorectomy by routine laparotomy. Extirpated ovaries underwent MWA at 45 W for 60 (n = 11) or 90 (12) seconds; 3 ovaries did not undergo MWA and served as histologic controls. Ovaries were histologically evaluated for cell viability. Ovaries without viable cells were categorized as completely ablated. Histologic results were used to identify the optimal MWA protocol for use in the subsequent trial. In the second trial, the ovaries of 9 dogs underwent MWA at 45 W for 90 seconds in situ. Ultrasonographic guidance for MWA was deemed unfeasible after evaluation of 1 ovary. The remaining 17 ovaries underwent MWA with laparoscopic guidance, after which routine laparoscopic oophorectomy was performed. Completeness of ablation was histologically assessed for all ovaries. RESULTS: 2 ovaries were excluded from the trial 1 analysis because of equivocal cell viability. Six of 11 ovaries and 10 of 10 ovaries that underwent MWA for 60 and 90 seconds, respectively, were completely ablated. In trial 2, laparoscopic-guided MWA resulted in complete ablation for 12 of 17 ovaries. Dissection of the ovarian bursa for MWA probe placement facilitated complete ablation. CONCLUSIONS AND CLINICAL RELEVANCE: Laparoscopic-guided MWA at 45 W for 90 seconds was feasible, safe, and effective for complete ablation of clinically normal ovaries in dogs.

Assessment of the effects of diet and physical rehabilitation on radiographic findings and markers of synovial inflammation in dogs following tibial plateau leveling osteotomy.

OBJECTIVE To determine the effects of an omega-3 fatty acid and protein-enriched diet, physical rehabilitation, or both on radiographic findings and markers of synovial inflammation in dogs following tibial plateau leveling osteotomy and arthroscopic surgery for treatment of cranial cruciate ligament disease. DESIGN Randomized, prospective clinical trial. ANIMALS 48 dogs with unilateral cranial cruciate ligament disease. PROCEDURES Dogs were randomly assigned to receive a dry omega-3 fatty acid and protein-enriched dog food formulated to support joint health (test food [TF]), a dry food formulated for adult canine maintenance (control food [CF]), TF plus rehabilitation, or CF plus rehabilitation after surgery. Synovial fluid prostaglandin (PG) E2 and interleukin-1ß concentrations, radiographic osteoarthritis scores, osteotomy site healing, and patellar ligament thickness were assessed at predetermined time points up to 6 months after surgery. RESULTS Dogs that received CF had significantly higher PGE2 concentrations over time following surgery than did dogs that received TF, regardless of rehabilitation status. Synovial fluid interleukin-1ß concentrations did not change over time in any groups. Diet and rehabilitation were both associated with osteoarthritis scores, with significantly lower scores over time for dogs that received TF versus CF and for dogs that underwent rehabilitation versus those that did not. Proportions of dogs with complete osteotomy healing 8 and 24 weeks after surgery were significantly lower for dogs that received TF than for dogs that received CF, regardless of rehabilitation status. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that feeding the TF can result in lower synovial fluid PGE2 concentrations and that both the TF and rehabilitation can reduce progression of osteoarthritis in the 6 months following tibial plateau leveling osteotomy; clinical relevance of slower osteotomy healing in dogs fed the TF was unclear.