Ventral acetabular augmentation for management of caudoventral luxation following total hip replacement in dogs.

OBJECTIVE: To report ventral acetabular augmentation with an internal fixator for management of caudoventral luxation following total hip replacement in dogs and to report clinical outcomes. MATERIALS AND METHODS: Clinical records from three UK-based referral hospitals were reviewed retrospectively between 2010 and 2020 to identify dogs with caudoventral hip luxation managed by ventral acetabular augmentation. Hip prosthesis component orientation was radiographically assessed to identify potential risk factors associated with the luxation. Clinical and radiographic assessments were performed at short-term (≤12 weeks) and long-term (>12 months) follow-up and all complications were recorded. A standardised owner telephone questionnaire was used to assess long-term outcomes when a clinical assessment was unavailable. RESULTS: Nine dogs were included. Risk factors contributing to the luxation could not be defined. Implants used included a string-of-pearls plate (6/9), a polyaxial locking plate combined with a polyethylene implant (1/9) or a polyethylene implant alone (2/9). Complications occurred in two of nine dogs, including recurrent luxation and femoral stem loosening; both dogs had received a polyethylene implant alone, of which one received explantation of the hip prosthesis. Median long-term follow-up was 39 months (range 13.5-62). Seven dogs who received a ventral acetabular plate achieved full function of the operated limb and the overall outcome was good for eight dogs. Follow-up radiographs revealed stable hip prostheses in dogs who received a ventral plate, with the longest assessment at 37 months postoperatively. Owner satisfaction was good for all cases. CLINICAL SIGNIFICANCE: Ventral acetabular augmentation can successfully manage caudoventral luxation following total hip replacement in dogs.

Total hip replacement for the treatment of atraumatic slipped femoral capital epiphysis in dogs.

OBJECTIVES: To evaluate dogs diagnosed with slipped femoral capital epiphysis which were treated by total hip replacement. METHODS: Clinical and radiographic records of consecutive cases of slipped femoral capital epiphysis treated by total hip replacement were reviewed. Longer-term follow-up was by owner questionnaire. RESULTS: Fifteen cases were identified; 14 were affected unilaterally, 1 bilaterally. Median age at presentation was 13 months (range 6 to 30); median weight was 35 kg (range 10 to 66). Radiographically, proximal femoral sclerosis was evident in 13 of 16 hips. Thirteen hybrid and three cemented total hip replacements were performed. One dog had a stem complication five months postoperatively necessitating explantation. All other total hip replacements remained functional. At four weeks postoperatively lameness and pain scores were improved in all cases. Fourteen total hip replacements were examined after three months. Lameness was mild in 2 limbs and absent in 12; pain on manipulation was not apparent in any case. Significant radiographic complications were not encountered. Telephone questionnaires were performed for 14 cases (15 total hip replacements) at a median of 22 months postoperatively (range 8 to 45). Lameness was reportedly absent for 12 limbs and intermittent in 3. All owners felt that their dogs' quality of life was good. CLINICAL SIGNIFICANCE: Total hip replacement can be a successful technique to treat slipped femoral capital epiphysis.

Treatment of lumbosacral discospondylitis by surgical stabilisation and application of a gentamicin-impregnated collagen sponge.

This report describes a case of lumbosacral discospondylitis in a two-year-old boxer dog. The dog had been presented with chronic hindlimb lameness and signs of lumbar spinal pain. The diagnosis was confirmed with a magnetic resonance imaging scan and positive blood culture. Following unsuccessful conservative management, the dog was treated with surgical stabilisation using screws and polymethylmethacrylate, and implantation of a gentamicin-impregnated collagen sponge into the L7-S1 disc space. This technique has not previously been described. The dog had a successful long-term outcome with complete resolution of clinical signs.

Presumptive exercise-associated peracute thoracolumbar disc extrusion in 48 dogs.

Forty-eight dogs were diagnosed with presumptive exercise-associated peracute thoracolumbar disc extrusion. The median age was seven years (range two to 11 years), and median bodyweight was 23 kg (range 10 to 41 kg). The duration of signs before presentation ranged from 0.5 to four days. Twenty-nine dogs were non-ambulatory, of which 17 were incontinent and two had lost pain perception. Pelvic limbs were hyporeflexic or areflexic in 11 dogs. Intervertebral disc narrowing was evident on radiographs in 44 dogs. Myelography demonstrated a small, extradural space-occupying lesion dorsal to an intervertebral disc between T11-12 and L3-4 with adjacent spinal cord swelling. Forty-six dogs were treated non-surgically, one was euthanased and one was managed by hemilaminectomy (and subsequently euthanased). Follow-up information was available for 46 dogs 1.5 to 55 months after injury (median 22 months) showing that pelvic limb function had improved in all cases and all non-ambulatory dogs had regained the ability to walk. Six dogs remained faecally incontinent, and one dog remained urinarily and faecally incontinent.

Hemilaminectomy and vertebral stabilisation for the treatment of thoracolumbar disc protrusion in 28 dogs.

OBJECTIVES: To evaluate the results of hemilaminectomy and vertebral stabilisation (+/- annulectomy) for the treatment of thoracolumbar disc protrusion. METHODS: The medical records of dogs with thoracolumbar annular protrusions treated by hemilaminectomy and vertebral stabilisation were reviewed. Neurological function was assessed 24 hours following surgery. Long-term follow-up was by clinical examination or telephone questionnaire. RESULTS: Twenty-eight dogs fulfilled the criteria. Age ranged from 4 to 12.5 years (median 8 years, mean 7.7 years), bodyweight from 5.1 to 51.5 kg (median 28 kg, mean 27.1 kg), and duration of neurological signs before presentation from 48 hours to 104 weeks (median 5 weeks, mean 9.3 weeks). At presentation 22 dogs were ambulatory and six were non-ambulatory. Myelography and/or magnetic resonance imaging (MRI) identified 31 thoracolumbar protrusions causing spinal cord compression. Unilateral hemilaminectomy was performed in 27 dogs and bilateral hemilaminectomy in one dog. Partial annulectomy was performed in 24 of 31 protrusions. Stabilisation was performed using vertebral body bone plates in 26 dogs and vertebral body screws and bone cement in two dogs. Internal vertebral venous plexus haemorrhage was recorded in nine dogs. A screw was inadvertently placed into an intervertebral disc in two dogs. Neurological examination 24 hours postoperatively revealed deterioration in pelvic limb motor function in 17 dogs. One dog was euthanatised at the owner's request 6 days after surgery. Long-term evaluation of 24 cases was performed 3 to 52 months following surgery (median 21 months, mean 23.9 months). Six dogs had improved from their preoperative status and one had deteriorated as assessed by the authors. Fifteen dogs had improved from their preoperative status and two were unchanged as assessed by owners. CLINICAL SIGNIFICANCE: Hemilaminectomy and vertebral stabilisation are an effective treatment for chronic spinal cord compression due to thoracolumbar annular protrusion in dogs. A temporary deterioration in neurological function is not uncommon following surgery. Internal vertebral plexus haemorrhage and inappropriate vertebral body screw placement are potential complications.

Treatment of fractures of the tibial and/or fibular malleoli in 30 cats.

Five cats were treated for a fracture of the medial malleolus, 10 for a fracture of the lateral malleolus and 15 for fractures of both malleoli. Open reduction and internal fixation with Kirschner wires (K-wires) with or without a tension band wire was applied to 26 of the fractures. Unilateral-uniplanar or bilateral-uniplanar transarticular external skeletal fixators were applied to provide coaptation in 19 cases and appeared to be well tolerated. In 24 cases fracture healing was assessed radiographically between four and eight weeks after treatment. In seven cases fracture healing was good, in 12 cases it was reasonable, in four cases it was poor and in one case with two fractures healing was poor in one and reasonable in the other. The 12 fractures treated by open reduction and internal fixation with K-wires and a tension band wire all showed evidence of good or reasonable healing. The nine fractures treated by open reduction and internal fixation with K-wires without a tension band wire showed evidence of good or reasonable healing in six cases and poor healing in three cases. Complications occurred in nine of the cats and included persistent talocrural instability, soft tissue necrosis, implant migration and external fixator pin breakage. Twenty-one of the cats were followed up by telephone questionnaire for between 5.5 and 84 months; the owner satisfaction was excellent in 17 cases, good in two cases, moderate in one case and poor in one case.

Complications following tarsal arthrodesis using bone plate fixation in dogs.

OBJECTIVES: To report the complications encountered following tarsal arthrodesis surgery with bone plate fixation and describe the previously unreported complication of plantar necrosis. METHODS: Medical records of 40 dogs that had been treated by tarsal arthrodesis with bone plate fixation were reviewed to determine the major and minor complications and the associated risk factors. RESULTS: The major complication rate was 32.5 per cent and the minor complication rate was 42.5 per cent. Pantarsal arthrodeses had a higher major complication rate than partial tarsal arthrodeses. Plantar necrosis was the most common major complication and occurred in 15 per cent of cases. Plantar necrosis occurred more frequently when a bone plate was applied to the medial aspect of the hock, and only occurred in cases where tarsometatarsal joint arthrodesis was performed. CLINICAL SIGNIFICANCE: Plantar necrosis is a catastrophic complication that may be associated with injury to the dorsal pedal artery or perforating metatarsal artery. Application of a bone plate to the medial aspect of the hock should be performed with care during tarsal arthrodesis, particularly where the tarsometatarsal joint is debrided of cartilage. Strict attention to surgical technique and proper postoperative coaptation is critical to reduce the potential for complications with tarsal arthrodesis.

Treatment of medial patellar luxation by femoral closing wedge ostectomy using a distal femoral plate in four dogs.

This case report describes the treatment of recurrent medial patellar luxation associated with varus deformity of the distal femur by distal femoral ostectomy stabilised using a distal femoral plate. Four dogs (five affected limbs) were included in the study. All cases had received previous surgery for medial patellar luxation but remained significantly lame. All were treated by femoral ostectomy to correct distal femoral varus deformity with application of a distal femoral bone plate. All cases improved following surgery. An excellent outcome was recorded in four of five cases. Lameness persisted in one case despite satisfactory patellar stability as a result of concurrent cranial cruciate ligament deficiency. One case suffered implant failure. Femoral ostectomy is an effective treatment for medial patellar luxation associated with femoral varus deformity. The distal femoral plate provides a convenient method by which to stabilise the ostectomy. Care should be exercised when the 2 mm distal femoral plate is applied.

Fragmented coronoid process in the dog: is there a role for incongruency?

Fragmented coronoid process in the dog is a common yet frustrating and poorly understood condition. Elbow joint incongruency, which refers to malalignment of the joint surfaces of the elbow, has been proposed as a key factor in the pathogenesis of fragmented coronoid process, and various surgical procedures have been devised to treat the proposed incongruency. However, precise characterisation of incongruency present in cases of fragmented coronoid process has not been reported consistently. In this article, the literature relating to the pathogenesis of fragmented coronoid process, the role of incongruency and its implications are reviewed.

Use of reconstructed computed tomography for the assessment of joint spaces in the canine elbow.

OBJECTIVES: To assess the accuracy of reconstructed computed tomography for imaging canine elbow joint spaces. METHODS: Computed tomography scans of eight cadaveric elbows were obtained and reconstructed computed tomography images were formatted in the dorsal and sagittal planes. Humeroradial and humeroulnar joint space measurements were obtained from these images. Intra-observer and inter-observer variations in joint space measurements were assessed, as was the effect of specimen positioning (inter-image variation). After freezing, four elbows were sectioned in the dorsal plane and four in the sagittal plane. In addition to visual comparison of the frozen sections with reconstructed computed tomography images, joint space measurements were obtained from frozen sections and compared with those from reconstructed computed tomography images. Variation was assessed using statistical calculations and graphical techniques. RESULTS: Both inter-image and intra-observer analyses revealed good agreement and low variation between data sets. Inter-observer correlation was only moderate, though variation was low. Visually, the reconstructed computed tomography images accurately reflected the frozen section anatomy. Agreement between frozen section and reconstructed computed tomography joint space measurements was good, with minimal variation. CLINICAL SIGNIFICANCE: These results indicate that reconstructed computed tomography is capable of accurately imaging elbow joint spaces and precise joint space measurements can be obtained. Reconstructed computed tomography may be useful for determining joint space measurements and detecting elbow incongruencies in dogs with elbow dysplasia.

Evaluation of elbow incongruency using reconstructed CT in dogs suffering fragmented coronoid process.

OBJECTIVES: A retrospective study was undertaken to evaluate elbow joint congruency in dogs suffering fragmented coronoid process (FCP). METHODS: Based on clinical, radiographic and computed tomographic (CT) examinations, elbows were divided into control and FCP groups. Standardised CT reconstructions were formatted in the frontal and sagittal planes. Humeroradial and humeroulnar joint space measurements were obtained from the Images and incongruencies were calculated by comparing the two measurements. RESULTS: Forty-two FCP and 29 control elbows were identified. No incongruencies were noted at the coronoid base. At the level of the coronoid apex, FCP elbows exhibited a significant radioulnar incongruency compared with controls (P < 0.0001), though incongruency was not identified in all cases. Comparing FCP and control elbows at the level of the apex, the humeroradial joint space was increased in FCP elbows (P = 0.0006) whereas no difference was noted in the humeroulnar space. CLINICAL SIGNIFICANCE: This study supports the hypothesis that joint incongruency is associated with FCP in dogs, though is not present in every case at the time of diagnosis. The precise mechanism of development of this incongruency cannot be determined from these data.

Treatment of canine and feline diaphyseal radial and tibial fractures with low-stiffness external skeletal fixation.

The healing of 62 cases of radial and tibial fractures treated with low-stiffness Kirschner-Ehmer external skeletal fixation frames (frame types 1a, 1a plus intramedullary pin [1aIMP], 1b and 2b) was evaluated. The mean time to clinical union was 65 days. All cases treated with 1b, 2b or 1aIMP frames healed. Four of 25 cases treated with 1a frames failed to heal due to premature pin loosening; these failures were in heavier patients than 1a cases which healed (P=0.041). Complications occurred in 40 of 62 cases, and were more common in cases treated with type 2b frames. Pin loosening was the most frequent complication (35 cases) and most commonly involved the most proximal pin (P<0.001). In type 2b frames, full pins loosened more frequently than half pins (P<0.001). This study indicates that canine and feline fractures can heal readily when treated with these frames, suggesting that more rigid type 2a or type 3 frames are unnecessary in the majority of cases. Increased morbidity compared with the use of more rigid frames need not be expected, but 1a frames should be avoided in heavier patients.

Complete patellar ligament replacement using a fascia lata autograft in a dog.

A novel technique for the repair of a chronically lacerated patellar ligament in a pet greyhound is described. The injury had been sustained traumatically, and a previous surgical repair had proved unsuccessful. On further surgical investigation, identification of the ruptured ligament ends was not possible. A double fascia lata graft was employed to reconstruct the lateral and medial portions of the ligament. This repair was augmented with 27 kg monofilament nylon anchored through tunnels from the proximal tibia to the patella and quadriceps tendon. A concurrent skin deficit was managed with a superficial epigastric axial pattern flap. To the authors' knowledge, only one previous case requiring complete patellar ligament replacement has been documented in the veterinary literature. This report details a simplified surgical technique which may have advantages over the previously described technique.