Lateral patellar luxation in dogs: a retrospective study of 65 dogs.

OBJECTIVE: To report the signalment and clinical features of dogs with non-traumatic lateral patellar luxation and to report the complications and outcomes following surgery. METHODS: A multicentre retrospective study was performed. Medical records were reviewed and the signalment, clinical features, and treatment of dogs presenting with lateral patellar luxation were recorded. In dogs treated surgically, the outcome and complications were investigated. RESULTS: Sixty-five dogs (95 stifles) were included; 39 were male and median age at presentation was 10 months. Breeds were classified as small (n = 6), medium (n = 23), large (n = 27), and giant (n = 9). Lateral patellar luxation was classified as grade I (n = 14), II (n = 41), III (n = 29), and IV (n = 11). Conformational abnormalities were noted in 34 stifles; genu valgum was the most common (n = 28). Higher-grade luxation was associated with a younger age at presentation (p = 0.032) and genu valgum (p = 0.01). Surgery was performed on 58 stifles, 22 of which sustained one or more complications; 16 complications were managed conservatively, four with implant removal and six with revision surgery. Surgeon-assessed outcome was good or excellent in 47 of the 51 dogs available for review. CONCLUSIONS: Non-traumatic lateral patellar luxation is a disease of predominantly medium and large breed dogs. It has several similar clinical features and can be surgically treated in a similar manner to medial patellar luxation with similar types of complications and outcomes expected.

Avulsion fragmentation of the tibial tuberosity apophysis and associated patellar tendon enthesopathy in a skeletally immature dog.

A 9.5-month-old, female entire, 31.3 kg crossbred dog was presented with a 12 week history of moderate weight-bearing right pelvic limb lameness. Radiographic, computed tomographic, and ultrasonographic imaging revealed progressive avulsion fragmentation of the right tibial tuberosity apophysis and a patellar tendon insertional enthesopathy without physeal involvement. Conservative management was successful in achieving a good clinical outcome. A progressive avulsion of the contralateral proximal tibial physes that occurred concurrently resulted in development of an excessive tibial plateau slope angle. The additional development of a moderate left distal femoral varus deformity was surgically corrected. This is the first report of a progressive, traction injury to the tibial tuberosity apophysis in a dog that appears clinically and radiographically very similar to Osgood-Schlatter disease in humans.

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.

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.

Preliminary experiences of the triple tibial osteotomy procedure: tibial morphology and complications.

OBJECTIVE: To document the effect of variable tibial morphology on the planning and execution of the triple tibial osteotomy (TTO) procedure in dogs and complications encountered while becoming familiar with the technique. METHODS: The records of 21 consecutive cases that had a TTO performed were reviewed. Preoperative tibial morphology was assessed. Modifications in the described technique and complications were documented. Postoperative outcome was evaluated using a client-based questionnaire. RESULTS: The size of the tibial wedge ostectomy was modified because of variable tibial morphology in four dogs (19 per cent) to avoid over or under correction of the tibial plateau angle (TPA). Intraoperatively, fracture through the caudal tibial cortex occurred in nine cases (41 percent) and through the distal tibial crest cortex in four cases (18 percent). Major complications occurred in five (23 per cent) of cases with four (18 per cent) requiring further surgery. The client questionnaire results demonstrated significant improvements in all parameters and no significant difference from the preinjury status. CLINICAL SIGNIFICANCE: TPA measurement is recommended when planning a TTO to avoid over or under correction of the TPA. Despite frequent minor complications, it appears that the TTO is an effective procedure for management of cranial cruciate ligament rupture in the dog.

Transverse stress fractures of the proximal tibia in 10 cats with non-union patellar fractures.

Ten cats with a mean age of eight years and five months had suffered proximal transverse tibial fractures; in four of them both tibiae had fractured at different times. All the cats also had bilateral non-union patellar fractures, and nine of them had evidence of fractures elsewhere, including acetabular, ischial, humeral condylar and rib fractures, which had occurred before or after the tibial fractures. All the tibial fractures were proximal and transverse. Radiographically, there was thickening and sclerosis of the cranial cortex adjacent to and at the level of the fracture, changes that were compatible with stress fractures. The outcome of repair of the tibial fracture was known in nine of the cats; eight of them healed and one resulted in a non-union. Two of the cats were euthanased as a direct result of the fracture or complications with the repair.

Vertebral stabilisation and selective decompression for the management of triple thoracolumbar disc protrusions.

Triple adjacent thoracolumbar disc protrusions causing moderate to severe spinal cord compression were diagnosed by magnetic resonance imaging in two German shepherd dogs with marked paraparesis and pelvic limb ataxia. Both cases were managed by selective hemilaminectomy, partial annulectomy and bilateral quadruple vertebral body stabilisation using novel canine locking fixation plates (SOP). The stabilisation of multiple vertebrae in the thoracolumbar spine was possible because the plates could be contoured with six degrees of freedom. Spinal pain resolved and neurological function improved in both dogs. Screw breakage was evident in one dog five months following surgery.

Rupture of the dura mater in two dogs caused by the peracute extrusion of a cervical disc.

A rupture of the dura mater caused by the peracute extrusion of a cervical disc was diagnosed by myelography in two dogs. In both cases traction on the cervical spine resulted in contrast medium entering the ruptured intervertebral disc from the subarachnoid space. Both dogs became suddenly tetraparetic and unable to ambulate during vigorous exercise, but regained the ability to walk without surgical treatment.

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.

Ossification of the infraspinatus tendon-bursa in 13 dogs.

Ossification of the infraspinatus tendon-bursa was diagnosed in 13 labrador retrievers, 12 of which were lame in one thoracic limb and the other in both. They ranged in age from 28 to 121 months (mean 69.4 months). The lameness developed gradually and was progressive in 11 of the 14 affected joints. Scapular muscle atrophy and signs of pain on direct pressure over the infraspinatus tendon of insertion were key clinical signs. Caudocranial radiographs revealed multiple mineralised masses lateral to the proximal humerus or glenohumeral joint in 11 of the 26 joints and single masses in 12. An arthroscopic examination revealed concomitant ligament or tendon abnormalities in six of seven shoulders. The dogs were followed up from one to 55 months (mean 20 months). Of five shoulders treated with non-steroidal anti-inflammatory drugs (nsaids), one resolved, two improved and two were managed surgically. Of six shoulders treated by the injection of long-acting intra-articular corticosteroid (five before and one after surgery), three resolved, two improved and one was unchanged. Of six shoulders treated by the surgical resection of the infraspinatus tendon and bursa (three before and two after treatment with nsaids, and one after treatment with a long-acting intra-articular corticosteroid), four improved, one was unchanged and one was managed with an intra-articular long-acting corticosteroid. One shoulder was managed by restricted exercise and the lameness resolved. Histological examination of the excised tissues revealed heterotopic bone within the infraspinatus tendon and/or bursa.

Ulnocarpal arthrodesis and limb lengthening for the management of radial agenesis in a dog.

Radial agenesis was diagnosed in a nine-week-old boxer. An ulnocarpal arthrodesis was performed when six months of age to improve limb alignment and enable weight bearing. When the dog was 10 months old, a hinged circular fixator was applied to the limb to gradually lengthen the ulna and correct angular and rotational deformity. The fixator was removed at 16 months of age. At this time, there was 1.7 cm (6 per cent) shortening of the affected antebrachium-metacarpus and 2.6 cm (15 per cent) compensatory overgrowth of the humerus compared with the contralateral limb. Inability to extend the digits was a complication that improved with physiotherapy. Follow-up at 23 months of age showed good limb use when walking and running. Radiographs of the elbow showed periarticular osteophytes and subcoronoid sclerosis of the ulna.

The value of oblique versus ventrodorsal myelographic views for lesion lateralisation in canine thoracolumbar disc disease.

OBJECTIVE: To determine the value of oblique versus ventrodorsal myelographic views for lesion lateralisation in canine thoracolumbar disc disease. METHODS: The ventrodorsal and oblique views from 196 lumbar myelograms of dogs with single thoracolumbar disc extrusions or protrusions were blindly and independently reviewed by two of the authors for evidence of lesion lateralisation. Medical records were reviewed for details regarding hemilaminectomy surgery. The side (left versus right) of the surgery and whether or not the disc material was retrieved were noted. RESULTS: Both reviewers lateralised significantly more disc lesions from the oblique views (93 and 95 per cent) than from the ventrodorsal views (59 and 70 per cent) (P<0.001). Using a combination of oblique and ventrodorsal views, 194 (99 per cent) and 195 (99.5 per cent) lesions were lateralised. Unilateral hemilaminectomy was performed in 193 dogs with myelographic lateralisation and in one dog without myelographic lateralisation. The side of spinal cord decompression corresponded with the myelographic findings in all dogs showing lateralisation on myelography. In the dog without myelographic lateralisation, a left (randomly chosen) hemilaminectomy revealed dorsal protrusion of the annulus fibrosus. CLINICAL SIGNIFICANCE: Myelography, including oblique, ventrodorsal and lateral views, is an accurate method for determining lateralisation of extruded or protruded disc material in the vertebral canal before decompressive surgery. Combined oblique and ventrodorsal views are more useful than either view alone and should be routinely obtained in all lumbar myelographic studies when investigating thoracolumbar disc disease.

Patellar luxation in 70 large breed dogs.

OBJECTIVES: To report the signalment, history, clinical features, and outcome in dogs weighing greater than 15 kg, treated surgically and non-surgically for patellar luxation. Risk factors for the development of patellar luxation, postoperative complications, and outcome were evaluated. METHODS: Details regarding signalment, bodyweight, breed, aetiology, unilateral or bilateral luxation, duration of lameness, grade of luxation, direction of luxation, grade of lameness at presentation, concomitant cranial cruciate ligament rupture, method of treatment, surgical technique, surgeon, and complications were obtained from the medical records. Outcome was graded as excellent, good, fair, or poor, according to the degree of lameness. RESULTS: Seventy dogs (45 males and 25 females) were included. Thirty-five had bilateral luxations (105 limbs). Mean age was two years, and mean weight was 30 kg. The relative risk for Labrador retrievers was 3.3 (P<0.001). All luxations were developmental. Luxations were medial in 102 stifles and lateral in three. Fourteen stifles had concomitant cranial cruciate ligament rupture. As the grade of patellar luxation increased, so did the grade of lameness (P<0.001). Surgery was performed in 70 stifles, and outcome was excellent/good in 94 per cent and fair/poor in 6 per cent of stifles. Complications occurred in 29 per cent of stifles, and increasing bodyweight was found to be a risk factor (P=0.03). Thirty-five stifles were managed non-surgically, and outcome was excellent/good in 86 per cent and fair/poor in 14 per cent of stifles. CLINICAL SIGNIFICANCE: In view of the potential risk of postoperative complications, all surgically treated cases of patellar luxation in large breed dogs should be managed with a femoral trochleoplasty, a tibial tuberosity transposition (stabilised with K-wires and a tension band wire), and soft tissue releasing and tightening procedures.

Y-T humeral fractures with supracondylar comminution in five cats.

Five cats with Y-T fractures of the humeral condyle were reviewed. Breeds presented included domestic shorthair (four cats) and Maine Coon (one cat). Age ranged from two to 16 years. All the cats were neutered males. A road traffic accident was suspected in all cases. Four of the fractures were severely comminuted and one fracture had four fragments. The fractures were repaired via combined medial and lateral approaches. Fixation of the epicondylar ridges was performed using buttress plates in four cases and neutralisation plates in one case. The intracondylar fracture was stabilised using a 2.7 mm lag screw in four cases and a 3.5 mm lag screw in the other. A corticocancellous bone graft was applied in two cases. The intracondylar fracture was accurately reduced in all cases. Complete radiographic healing was documented in two cases 6 and 11 weeks following surgery. Failure of the fixation occurred in the most severely comminuted fracture five days postoperatively. Surgical revision was not performed, and the limb was amputated. Three cats were free of lameness and had resumed outdoor activities at follow-up (five to eight months after surgery). Marked lameness due to loss of elbow movement was observed in the other case.

Bilateral fixation of Y-T humeral condyle fractures via medial and lateral approaches in 29 dogs.

OBJECTIVES: To describe bilateral fixation of Y-T fractures of the humeral condyle via combined medial and lateral approaches, and to determine the technique's clinical and radiographic short-term outcomes. METHODS: Details of 30 consecutive fractures in 29 dogs were reviewed. These included signalment, method of fixation, complications, and follow-up limb function and range of elbow joint motion. RESULTS: The age of the dogs ranged from three months to nine years, and bodyweight ranged from 1.9 to 48 kg. The humeral condyle was reattached to the shaft using medial and lateral bone plates in 18 fractures, a medial plate and lateral Kirschner wire(s) in six fractures, and medial and lateral Kirschner wire(s) in six fractures. Major complications were recorded in four fractures and minor complications in two fractures. Limb function at follow-up was graded as excellent in 12, good in 15 and fair in three fractures. The range of elbow flexion was normal in seven, mildly reduced in 18, moderately reduced in four and severely reduced in one fracture. CLINICAL SIGNIFICANCE: In contrast to the caudal approach, combined medial and lateral approaches decrease the extent of periarticular soft tissue dissection, avoid complications associated with olecranon osteotomy and enable exposure of the entire humeral diaphysis for fixation. Bilateral fixation is likely to be better at counteracting bending and torsional forces compared with unilateral fixation.

Spontaneous healing of a trophic ulcer of the metatarsal pad in a dog.

A two-year-old whippet cross presented with a large ulcer of the right metatarsal pad. Laceration of the plantar aspect of the metatarsal region involving the flexor tendons had occurred 10 days prior to ulcer formation. Pain sensation was absent distal to the wound, indicating tibial nerve damage. A presumptive diagnosis of trophic ulceration of the metatarsal pad secondary to tibial nerve injury was made. Sensory nerve function returned within 14 weeks and the trophic ulcer subsequently healed. Spontaneous resolution of trophic ulceration has been reported in humans but, to the authors' knowledge, not in dogs.

Pantarsal arthrodesis with a customised medial or lateral bone plate in 13 dogs.

Pantarsal arthrodesis was performed in 12 dogs using a customised medial bone plate, and in one using a lateral bone plate. The dogs' ages ranged from 14 months to 144 months (median 30 months) and their bodyweights ranged from 7 to 66 kg (median 32 kg). Before the surgery they had been lame on a pelvic limb for between one and 16 months (median eight months). In eight of the dogs the fixation of the plate was augmented with a calcaneotibial positional screw, and in one of them with a talocrural lag screw. A cranial half cast was applied to 12 of the dogs and an external skeletal fixator to the other for six to eight weeks. Five complications were recorded in four of the dogs. Between 29 and 156 weeks postoperatively the clinical outcome was graded as excellent in six dogs, good in six dogs and fair in the other.

Caudal proximal tibial deformity and cranial cruciate ligament rupture in small-breed dogs.

Eight dogs presented with chronic hindlimb lameness associated with cranial cruciate ligament rupture. Seven were small terriers. A caudal deformity of the proximal tibial shaft, originating at the proximal tibial physis, and an excessive caudal slope of the tibial plateau were present bilaterally in all dogs. The deformity was thought to be responsible for the cranial cruciate ligament failure and poor response to conservative management. Tibial plateau angles were in excess of 26 degrees in all dogs. The lameness was bilateral in three dogs. There was complete cranial cruciate ligament rupture in seven stifles and partial rupture in four. There were no meniscal injuries. Surgical correction resulted in a significant improvement (P<0.0001) in all dogs, with a mean follow-up of 12 months (range three to 24 months). There were no complications.