Caudal pole meniscectomy through an arthroscopic caudomedial portal in dogs: A cadaveric study.

OBJECTIVE: To describe a caudomedial instrumental portal for caudal pole meniscectomy (CPM). STUDY DESIGN: Experimental ex-vivo study. SAMPLE POPULATION: Ten cadaveric hindlimbs of 10 large breed dogs. METHODS: Each hindlimb was used for establishing the caudomedial portal for CPM. The surgical time was recorded. Specimens were disarticulated afterwards, and the completeness of CPM was documented. Iatrogenic injuries to the articular cartilage and the intra- and periarticular structures were assessed. RESULTS: The extent of the CPM (mean ± SD, percentage of the resected medial meniscus) was 29.8 ± 12.9% of the area of the medial meniscus. There were no injuries to the medial collateral ligament or caudal cruciate ligament. The mean iatrogenic articular cartilage injury (IACI) was 3.71 ± 1.78% of the area of the medial meniscus. CONCLUSION: The establishment of a caudomedial portal for CPM in canine cadavers was feasible and allowed to perform a partial caudal pole meniscectomy. CLINICAL SIGNIFICANCE: A caudomedial portal may be considered for CPM in selected cases when caudal tears cannot be accessed through the standard portals.

Outcome and Complications following Stabilization of Coxofemoral Luxations in Cats Using a Modified Hip Toggle Stabilization-A Retrospective Multicentre Study.

OBJECTIVES: The main aim of this study was to report the surgical technique, the complications and the clinical outcomes of the mini-Tight Rope system (mini-TR) for a modified hip toggle stabilization of coxofemoral luxation in cats. STUDY DESIGN: A multicentre retrospective study. ANIMALS: Thirty-two client-owned cats. METHODS: Medical records (2009-2017) of cats, which underwent stabilization of a coxofemoral luxation with the mini-TR and had at least a 3-month follow-up, were reviewed. The femoral tunnel diameter, the use of one or two FiberWire loops, perioperative complications and clinical outcomes were recorded. Follow-up information was obtained through clinical and radiographic examinations and an owner questionnaire. RESULTS: Thirty-two cats met the inclusion criteria. Concurrent injuries were present in 16 cats. A single or double loop mini-TR was used in 21 and 12 cats respectively. One double loop (1/12 cats) and four single loop (4/16 cats) sutures failed. Moderate-to-severe coxofemoral osteoarthritis developed in 14/27 cats. Owner questionnaires revealed excellent clinical outcomes. CLINICAL SIGNIFICANCE: Mini-TR with a double-stranded implant is recommended to decrease the risk of suture failure. Osteoarthritis is common after open reduction of hip luxations.

Patient specific, synthetic, partial unipolar resurfacing of a large talar osteochondritis dissecans lesion in a dog.

OBJECTIVE: To describe the application and early outcome of a custom-made unipolar partial tarsal replacement in a dog with an extensive medial talar ridge OCD. ANIMAL: A 7-month-old, 25 kg male Rhodesian Ridgeback with progressive left hindlimb lameness (grade III-IV/IV) and diagnosis of talar OCD. METHODS: The dog presented with progressive lameness attributed to extensive medial talar ridge OCD. Due to the severity of the lesion, a resurfacing procedure was chosen. Based on CT data, a bi-layered resurfacing implant consisting of a titanium socket and a polycarbonate urethane bearing surface was constructed. For intraoperative guidance, a set of matching drill guides were 3D-printed, along with some models of the affected talus, to allow for dry-lab training. Surgical implantation using a medial malleolar osteotomy to approach the lesion was without complications. Orthopedic follow-up examinations were conducted at 10 days, 4 weeks, 6 weeks, 6 months and 12 months. Radiographic examinations were included at the 6-week, 6-month, and 12-month follow-ups. RESULTS: Function improved considerably during the follow-up period with a lameness grade of 0-I/IV at the 12-month follow-up. ROM differed by 15° in flexion compared to the contralateral side, while there was no difference in extension. Moderate periarticular fibrosis was present at 12 months. Implant positioning was unchanged at follow-up-radiographic examination and there was only mild progression of osteoarthritis (OA). CONCLUSION: Patient specific instrumentation - guided tarsal OCD resurfacing with a synthetic patient-specific implant may be an effective treatment option.

Ex vivo comparison of lateral plate repairs of experimental oblique ilial fractures in cats.

OBJECTIVE: To determine the biomechanical behavior of different plate systems used for oblique ilial fracture fixation in cats. STUDY DESIGN: Ex vivo biomechanical study. SAMPLE POPULATION: Fifty fresh-frozen feline hemipelvises. METHODS: Standardized simple oblique ilial fractures were created and fixed via lateral plating, using different implant systems (10 fractures in each group) The systems were: (1) the Advanced Locking Plate System (ALPS-5); (2) the Advanced Locking Plate System (ALPS-6.5); (3) the Locking Compression Plate 2.0 (LCP); (4) the FIXIN 1.9-2.5 Series (FIXIN), and (5) the Dynamic Compression Plate 2.0 (DCP). Stepwise sinusoidal cyclic loading was applied until failure (10-mm displacement). The groups were compared with regard to construct stiffness and the number of cycles withstood before 1-, 2-, 5-, and 10-mm displacement. RESULTS: Bending stiffness was lower in ALPS-5 than in other specimens (P < .05). The ALPS-6.5 specimens withstood more cycles (P < .05) before 2-, 5-, and 10-mm displacement than the ALPS-5 and DCP specimens . The LCP and FIXIN specimens endured more cycles than DCP specimens before displaying 5- and 10-mm displacement (P < .05). The ALPS-6.5, FIXIN, and LCP specimens endured higher loads before failure than the DCP specimens (P < .05). Screw loosening occurred in all nonlocking specimens, and bone slicing occurred in all locking specimens. CONCLUSION: The DCP and ALPS-5 constructs are less resistant to cyclic loading. Failure in nonlocking specimens involved screw loosening. It involved bone slicing in locking specimens. CLINICAL SIGNIFICANCE: Both the plate size and the plate-screw interface are key to lateral plating success in cases of feline ilial fractures. The use of locking plates reduces the risk of the screw loosening in such cases.

Randomized controlled trial of pregabalin for analgesia after surgical treatment of intervertebral disc disease in dogs.

OBJECTIVE: To assess the effect of perioperative pregabalin on pain behavior in dogs after intervertebral disc surgery. STUDY DESIGN: Prospective, randomized, controlled clinical trial with a blinded observer. ANIMALS: Forty-six client-owned dogs undergoing intervertebral disc surgery. METHODS: Dogs were randomly assigned to two groups, with the placebo group receiving opioids alone and the pregabalin group receiving opioids plus pregabalin. Opioid analgesia consisted of 0.6 mg/kg l-methadone given intravenously at anesthetic induction, followed by 0.2 mg/kg given at 8, 16, and 24 hours after extubation and fentanyl patches applied at the end of surgery. Pregabalin was given orally (4 mg/kg) 1 hour before anesthesia, followed by postoperative treatment three times per day (4 mg/kg) for 5 days. The outcome measures were the treatment-group differences in peri-incisional mechanical sensitivity and Glasgow Composite Measure Pain Scale (CMPS-SF) assessed during the first 5 postoperative days. Pregabalin serum concentrations were measured after 24, 72, and 120 hours. RESULTS: Pregabalin reduced pain levels in the treatment group by a mean of 2.5 CMPS-SF units (95% confidence interval [CI] = -3.19 to -1.83, P < .001) compared with the control group during the study period. Pregabalin increased the mechanical nociceptive threshold by a mean of 6.89 N per day (95% CI = 1.87-11.92, P < .001) and of 7.52 N per day (95% CI = 2.29-12.77, P < .001) during the study period, depending on location. Mean levels of serum pregabalin were 5.1, 4.71, and 3.68 µg/mL at 24, 72, and 120 hours postoperatively, respectively. CONCLUSION: Postoperative signs of pain after surgical treatment of intervertebral disc herniation (IVDH) were reduced when dogs received perioperative pregabalin rather than opioids alone. CLINICAL SIGNIFICANCE: Perioperative pregabalin reduces postoperative pain after surgical treatment of IVDH.

Recommendations for rehabilitation after surgical treatment of cranial cruciate ligament disease in dogs: A 2017 survey of veterinary practitioners.

OBJECTIVE: To report current recommendations made by veterinarians for rehabilitation after surgical treatment of cranial cruciate ligament (CrCL) disease. STUDY DESIGN: Anonymized electronic survey. SAMPLE POPULATION: Veterinarians performing CrCL stabilization. METHODS: An electronic survey was created to collect information on general attitudes toward postoperative rehabilitation and recommendations regarding therapeutic modalities and bandaging. Quantitative data are reported by descriptive statistical analysis, percentage of responses, or mean (±SD). The recommendations for postoperative bandaging beyond 24 hours and for postoperative rehabilitation after extracapsular stabilization compared with after tibial osteotomy were tested by using Cochran-Mantel-Haenszel tests, with P < .05 considered statistically significant. RESULTS: The data analysis included 376 responses (13% response rate). Most (71%) respondents consistently recommended postoperative rehabilitation. Rehabilitation was more than twofold more likely to be recommended after extracapsular stabilization than after osteotomies (P = .0142). Most respondents did not recommend bandaging beyond 24 hours postoperatively (P = .00012). CONCLUSION: Most respondents recommended either formal or informal postoperative rehabilitation therapy. CLINICAL SIGNIFICANCE: If the survey respondents are representative of veterinarians performing CrCL surgery, the current attitude is supportive of postsurgical rehabilitation. Most respondents would welcome evidence-based guidelines for rehabilitation protocols.

Biomechanical comparison of knotted and knotless stabilization techniques of the tarsal medial collateral ligament in cats: A cadaveric study.

OBJECTIVE: To compare mechanical properties of intact feline medial collateral ligaments and three techniques for treatment of feline medial tarsal instability. STUDY DESIGN: Controlled laboratory study. SAMPLE POPULATION: Forty-eight normal, adult feline tarsi. METHODS: Three repairs were tested: a bone tunnel with polypropylene (PP) suture, a bone tunnel with polyethylene (PE) cord, and a knotless anchor technique with PE cord. A cyclic (6-N preload; 5-N amplitude; 2-Hz frequency) tensile test (600 cycles) was performed on feline tarsi with either the long or the short medial tarsal ligament intact, with each reconstruction technique followed by a single-cycle load-to-failure test (0.5 mm/s) with a failure point at 2 mm of displacement. Total elongation, peak-to-peak elongation, stiffness, and maximum load to failure point were compared with the intact condition. RESULTS: No differences in stiffness, total elongation, or peak-to-peak elongation were found between specimens repaired with the knotless technique and intact controls (P > .04), whereas tarsi repaired with the tunnel technique and PP were weaker (P < .008). Total and conditioning elongation were greater after tunnel reconstruction with PP than after knotless reconstruction (P = .005). Mean load to 2 mm of displacement tended (P = .03) to be higher after knotless than after knotted PP repairs and did not differ (P = .47) between tarsi repaired with the tunnel or anchor repairs with PE. CONCLUSION: The mechanical properties of intact tarsi were superior to those of tarsi repaired with tunnel techniques and PP but were similar to those of tarsi repaired with knotless techniques with PE. CLINICAL SIGNIFICANCE: Feline tarsal stabilization with the knotless technique for tarsal medial collateral ligament insufficiency may reduce the requirement for or duration of postoperative coaptation.

Custom acetabular prosthesis for total hip replacement: A case report in a dog with acetabular bone loss after femoral head and neck ostectomy.

OBJECTIVE: To describe the application of a custom acetabular prosthesis (CAP) for total hip replacement (THR) in a dog 20 months after femoral head and neck ostectomy (FHNO). STUDY DESIGN: Case report. ANIMAL: A 10-year-old, male, castrated, Labrador retriever with progressive lameness and pain after FHNO. METHODS: Acetabular bone stock was assessed as insufficient for conventional THR, so a biflanged CAP was designed and three-dimensionally printed in titanium to bridge the bone defect. The CAP had a porous surface for long-term biologic fixation on the backside and was anchored to the ilium and ischium with screws. A polyethylene cup was cemented into the CAP, and a bolted cementless femoral stem was inserted. RESULTS: The loss of the conventional anatomic landmarks complicated intraoperative orientation and led to eccentric reaming and 5-mm malalignment of the CAP. Reduction of the prosthetic joint was difficult because of periarticular fibrosis, loss of functional muscle length, and thickness of the CAP, and intraoperative shortening of the stem neck was required. Postoperative complications included sciatic neurapraxia, which resolved with time and conservative management. Absence of pain and improvement of range of motion were observed at clinical examination 12 months after surgery; however, moderate hind limb lameness persisted due to muscle tension. No evidence of implant loosening was noted on radiographs acquired 24 months after surgery. CONCLUSION: Femoral head and neck ostectomy with poor functional outcome was ameliorated by using a CAP in this dog. CLINICAL SIGNIFICANCE: Use of a CAP can be considered to treat acetabular defects in dogs.

Safety and Accuracy of Minimally Invasive Long Bone Fracture Repair Using a 2.5-mm Interlocking Nail: A Cadaveric Feline Study.

OBJECTIVES: The Targon Vet System (TVS) is a 2.5-mm interlocking nail that can be applied minimally invasively. The purpose of this study was to test if the TVS could be safely applied percutaneously to different feline long bones without fluoroscopic guidance. METHODS: A gap fracture was created in 96 feline humeri, femora and tibiae (n = 32/group). Paired bones were randomly assigned to two treatment groups: (1) TVS inserted percutaneously with fluoroscopy and (2) TVS inserted percutaneously without fluoroscopy. Intraoperative evaluation (complications, procedure time, attempts), radiographs (pre-/postoperative alignment, length) and anatomical dissection (neurovascular injury, rotational alignment) were compared between treatment groups. RESULTS: The use of fluoroscopy did not lead to significant differences in any of the outcome measures. Intraoperative complications predominantly occurred in the distal humerus (12/32) and the proximal femur (7/32). In total, 20/96 complications occurred with no complications for the tibia. Neurovascular structures were only damaged at the medial side of the distal humerus (10/32). CLINICAL SIGNIFICANCE: We conclude that the TVS can be safely applied percutaneously to the tibia and with limitations to the femur in normal cadaveric cats without fluoroscopy. Despite the limitations of a cadaveric study, the high number of complications is leading us to consider the humerus not safe for the TVS. A learning curve has to be expected and technical recommendations should be respected to decrease complications.

Biomechanical properties of plate constructs for feline ilial fracture gap stabilization.

OBJECTIVE: To determine the biomechanical properties of plating techniques for comminuted feline ilial fractures. STUDY DESIGN: Ex vivo study on 40 paired feline hemipelves. SAMPLE POPULATION: Forty paired fresh-frozen hemipelves that had been collected from 20 cats aged 2-6 years and weighing 4.0-5.5 kg. METHODS: A transverse 3-mm gap was created in each ilium. Hemipelves were fixed with one of the following methods (n = 10 per group): (1) a dorsal plate and nonlocking screws, (2) a lateral plate and nonlocking screws, (3) a lateral plate and locking screws, or (4) a lateral and dorsal locking compression plate using nonlocking screws. Each specimen was subjected to incremental, sinusoidal cyclic loading until failure, defined as 10-mm displacement. The initial stiffness and number of cycles required to reach 1-, 2-, 5-, and 10-mm axial displacement were statistically analyzed. RESULTS: The initial stiffness and number of cycles to failure were higher in specimens fixed with double nonlocking plates than in all other fixations (P < .05) except specimens fixed with lateral locking plate at 10-mm displacement (P = .44). Locking implants withstood more cycles to 5- (P < .05) and 10-mm (P < .05) displacement compared with other single-plate nonlocking groups. Screw loosening occurred only in the 3 nonlocking fixations. CONCLUSION: Double plating improved stiffness and resistance to failure of comminuted feline ilial fracture constructs compared with all other fixations. Single locking plates produced superior constructs compared with single nonlocking constructs. CLINICAL SIGNIFICANCE: Locking implants are recommended to repair comminuted feline ilial fractures for their extended fatigue life and resistance to screw loosening. Orthogonal plating offers a strong nonlocking alternative.

Guidelines for surgical approaches for minimally invasive plate osteosynthesis in cats.

OBJECTIVES: Minimally invasive plate osteosynthesis (MIPO) is one of the most recent fixation techniques that embody the concept of biological osteosynthesis. Several studies evaluating MIPO in dogs have been published in the recent years. However, there are few clinical reports of MIPO in cats and no description of the surgical approaches. The purpose of our study was to describe the safe corridors for plate insertion in cats using the MIPO technique. METHODS: The surgical approaches for the humerus, radius-ulna, femur and tibia were developed after reviewing the described techniques and surgical approaches for MIPO in dogs, while considering any relevant anatomical difference between dogs and cats. Following the MIPO approaches, the limbs were anatomically dissected and the relationship between proximal and distal positions of the implants and neurovascular structures was noted. RESULTS: The surgical approaches developed for the humerus and radius-ulna differed from what had been reported previously, because relevant anatomical differences were found between dogs and cats. Anatomical landmarks for safe plate application were described for all the major long bones in cats. No damage to vital structures following plate insertion was detected in the dissection. CLINICAL SIGNIFICANCE: In this cadaveric study, we evaluated the safety of the surgical approaches for MIPO in cats. By respecting the anatomical landmarks described in this report, damage to the neurovascular structures can be avoided performing the MIPO technique in cats.

Screw Loosening and Pelvic Canal Narrowing After Lateral Plating of Feline Ilial Fractures With Locking and Nonlocking Plates.

OBJECTIVE: To compare the frequency of complications, including screw loosening and pelvic canal narrowing, associated with dynamic compression plating, locking plating, and double locking plating of ilial fractures in cats. STUDY DESIGN: Historical cohort study. METHODS: The radiographs and medical records of cats with pelvic fractures that were presented between 2004 and 2013 were reviewed. The cases were categorized based on the plate type and number as dynamic compression plate (DCP), single locking plate (LPS) and double locking plates (dLPS). The frequency of screw loosening was compared across categories using a Fisher's exact test. The change in pelvic alignment, described by the change in sacral index (postoperative sacral index-followup sacral index), was compared across plate categories using ANOVA. RESULTS: The frequency of screw loosening for DCP (5/10) was significantly higher than LPS (1/13) and dLPS (0/11) (P = .05, P = .012, respectively). There was no significant difference in the SI change across plate categories. The mean change in sacral index for DCP was -0.11 (95%CI -0.25 to 0.03), for LPS was 0.0007 (95%CI -0.07 to 0.08), and for dLPS was -0.01 (95%CI -0.04 to 0.02). None of the cats showed constipation postoperatively. CONCLUSION: Screw loosening occurred less often but the change in pelvic canal alignment was not significantly different in ilial fractures repaired with LPS or dLPS compared to ilial fractures repaired with DCP. Locking plating of ilial fractures in cats may offer advantages compared to nonlocking plating.

Novel avulsion pattern of the left principal bronchus with involvement of the carina and caudal thoracic trachea in a cat.

A 2-year-old, 4.5 kg, neutered male domestic shorthair cat was presented to the emergency service with dyspnoea, anorexia and apathetic behaviour. Thoracic radiographs showed typical signs for a thoracic trauma and a tracheal lesion in the region of the carina, consistent with pseudoairway formation. Computed tomography (CT) was performed in the conscious cat to avoid aggravation of air leakage associated with ventilation. The additional CT findings were consistent with a novel pattern of a traumatic avulsion of the left principal bronchus expanding into the carina and caudal thoracic trachea. Despite the complex avulsion pattern, successful treatment was achieved surgically by performing an end-to-end anastomosis via a fifth right intercostal lateral thoracotomy. The cat was ventilated with a feeding tube and jet ventilation throughout. The cat showed excellent recovery 6 months after surgery.