Conservative management of fractures of the third metatarsal bone in the racing greyhound.

OBJECTIVE: To assess (2006 to 2012) conservative management for treatment of fractures of the third metatarsal bone (MT3) in racing greyhounds. METHODS: All racing greyhounds with MT3 fractures seen prospectively between 2006 and 2012 were included. Fracture morphology, type of conservative management, outcome and the time to a return to racing were recorded. Outcome was assessed either by communication with the trainer or by accessing the website of the Greyhound Board of Great Britain to find the complete racing history of the dog. RESULTS: Eighteen cases were evaluated. Six had a support dressing and 12 had no external dressings, treatment consisting of kennel rest alone. Two dogs were retired from racing at the time of injury, two dogs sustained other injuries and the remainder (n=14) returned to successful racing with no loss of form. CLINICAL SIGNIFICANCE: Conservative management for MT3 fractures consisting of a programme of exercise restriction carries an excellent prognosis for a return to previous racing form. External support dressings do not appear to be necessary either for the welfare of the dog or for fracture management.

Observer variation in the evaluation and classification of severe central tarsal bone fractures in racing Greyhounds.

OBJECTIVES: To determine observer agreement on radiographic evaluation of central tarsal bone (CTB) fractures and compare this with evaluation of the same fractures using computed tomography (CT). METHODS: Radiographs and CT scans were obtained of the right tarsi from limbs of Greyhounds euthanatized after sustaining severe CTB fracture during racing. Four observers described and classified each fracture. Inter- and intra-observer agreements were calculated. RESULTS: Inter-observer agreement was higher for assessment of fractures using CT. Several fractures assessed by radiography were misclassified as a less severe type. Intra-observer agreement for assessment and classification of CTB fractures via radiography versus CT was variable. Overall agreement among all four observers was higher for CT than radiography. Additionally, when identifying fractures of the adjacent tarsal bones, observer agreement was higher for CT than radiography. CLINICAL SIGNIFICANCE: Computed tomography improved observer ability to correctly evaluate CTB fracture and detect the degree of displacement and extent of any comminution. Identification of fractures of adjacent tarsal bones was also improved when tarsi were assessed using CT. These data suggest that treatment decisions based solely on radiographic assessment of CTB fractures may not produce the expected outcome.

Third tarsal bone fractures in the greyhound.

OBJECTIVE: To describe the signalment, morphology, response to treatment and prognosis of third tarsal bone fractures in the racing greyhound. METHODS: All third tarsal bone fractures seen by the author over a ten year period were included in the study. Diagnosis was by radiography. Treatments were reconstruction with a lag screw, fragment removal, centrodistal joint arthrodesis or conservative management. RESULTS: Twenty-three cases were included in the study of which 16 cases were recent and seven cases chronic fractures. The chronic cases had been rested from between three and six months before an examination for recurrent lameness. There were five concomitant second tarsal bone fractures. Partial dorsal collapse was present in four cases. Thirteen dogs had lag screw fixation; three were lost to follow-up, seven returned to racing and three, all with partial tarsal collapse, failed to return to racing. Two dogs that had a centrodistal joint arthrodesis and one dog treated by rest alone raced again. Two dogs that had fragment removal failed to return to racing. CLINICAL SIGNIFICANCE: Veterinary examination of greyhounds with third tarsal bone fractures is often not sought at the time of the initial injury due to the benign presenting signs. Recurrence of lameness after rest is common. The prognosis for a successful return to racing would appear to be good following fragment fixation in both acute and chronic cases without dorsal tarsal collapse. Centrodistal joint arthrodesis may encourage bone union. The prognosis for conconservatively treated cases is guarded. Fragment removal is not recommended as a treatment.

Corns in dogs; signalment, possible aetiology and response to surgical treatment.

OBJECTIVES: To describe the signalment and response to surgical treatment, and to propose aetiopathogenetic mechanisms for the development of paw pad corns in dogs. METHODS: A combined retrospective and prospective study was conducted on 30 dogs that presented with paw pad corns. The age, breed and gender of the dogs, together with anatomical positions of the corns were recorded. Surgical treatments involved either excision (n=27) or distal digital ostectomy (n=3). The minimum follow-up period was one year. RESULTS: The age at presentation was from two to 15 years. All the breeds in this study were either greyhounds or sighthounds. Males were over-represented. Ninety percent of the corns were found in the digital pads of digits three and four, and 90% were found in the thoracic limbs. The evidence suggests a mechanical aetiology or foreign body penetration. Long-term response to surgical excision resulted in a recurrence rate of more than 50% (n=27). Distal digital ostectomy gave good results in selective cases (n=3). CLINICAL SIGNIFICANCE: Corns can cause severe chronic lameness in greyhounds and related breeds. Long-term response to surgical treatments is disappointing but it is recommended as an initial treatment as it can be curative.

Stabilisation of medial shoulder instability by imbrication of the subscapularis muscle tendon of insertion.

OBJECTIVES: To evaluate the efficacy of subscapularis muscle tendon of insertion imbrication as a treatment for medial shoulder instability. METHODS: Medial shoulder instability was diagnosed in five dogs. Initial management with medical or arthroscopic treatment failed to fully resolve lameness in four of the cases. Each case was treated by subscapularis muscle tendon of insertion imbrication. An anatomical model of medial shoulder instability was used to assess the effect of subscapularis muscle tendon of insertion imbrication on the angle of abduction of the shoulder. RESULTS: In clinical study, subscapularis muscle tendon of insertion imbrication was performed in five cases. Lameness resolved fully in three cases and partially in two cases. In cadaver study, transection of either the subscapularis muscle tendon of insertion or the subscapularis muscle tendon of insertion and medial glenohumeral ligament significantly increased the angle of abduction. Imbrication of the subscapularis muscle tendon of insertion significantly reduced the angle of abduction. No significant differences were noted between the angle of abduction of normal shoulder and the shoulder with medial shoulder instability treated by subscapularis muscle tendon of insertion imbrication. CLINICAL SIGNIFICANCE: Subscapularis muscle tendon of insertion imbrication is a moderately effective procedure for the management of medial shoulder instability unresponsive to medical and/or arthroscopic management. The angle of abduction of the shoulder was returned to normal in model of medial shoulder instability, following subscapularis muscle tendon of insertion. Subscapularis muscle tendon of insertion imbrication provides a relatively simple method of treating medial shoulder instability in dogs.

Centrodistal joint lameness in dogs.

Lameness attributable to pathology of the centrodistal joint was investigated in five racing greyhounds, five Border collies and two other dogs. Diagnosis was made by the induction of pain from rotationally stressing the medial aspect of the tarsus, and by the exclusion of tarsal fractures and instabilities. Radiographic changes included plantar ligament entheslopathy and centrodistal joint osteophytosis. In many of the cases, the lameness was poorly responsive to rest and non-steroidal anti-inflammatory drugs. One dog was managed conservatively and became sound. In 10 of 11 cases, surgical promotion of centrodistal ankylosis was associated with a return to soundness.

Proximal interphalangeal joint instability in the dog.

A prospective study into the use of transarticular external skeletal fixation in the treatment of proximal interphalangeal instability was undertaken. Only dogs with soft tissue injuries were included. All the dogs except one were greyhounds or related breeds. A hypothesis was proposed that if the articular surfaces were held in normal congruency for a period of time then the development of periarticular fibrosis would alone give sufficient joint support. Joint congruency was maintained by the application of a unilateral external skeletal fixator for approximately three weeks. Complications were common and were due to frame impingement on the neighbouring digit, pin tract infection and pin loosening, and all resolved following frame removal and antibiotic therapy. Careful pin placement and prophylactic antibiotic treatment prevented complications in subsequent cases. All dogs returned to normal function with no lameness, with the exception of one racing greyhound which had a recurrence of the instability.

Dorsal tarsal instability in three racing greyhounds.

Rupture of the dorsal ligaments of the tarsus in the greyhound is a rare racing injury. This case report describes dorsal tarsal instability in three greyhounds. A stumble and somersault were observed in two cases and were thought to have caused the injury. Previous reports advocate partial intertarsal arthrodesis as the preferred treatment for dorsal instability of the proximal intertarsal joint, but not all dogs returned to successful racing. In these three cases, stability was restored by the insertion of a wire tension band anchored to two bone screws, allowing the development of periarticular fibrosis. The dogs raced again with no loss of form.

Fibrodysplasia ossificans in a German shepherd dog.

Bilateral cervical heterotopic ossification, associated with a thoracic limb lameness, occurred in an adult German shepherd dog. One of the lesions, thought to be the cause of the lameness, was surgically removed and the lameness resolved. The lesion was classified morphologically as fibrodysplasia ossificans. A similar, smaller lesion was present over the cranial distal scapular border. The causes of ectopic ossification, as described in the veterinary literature, are reviewed and compared with myositis ossificans in humans. Non-progressive fibrodysplasia ossificans has been described in cats, but this appears to be the first report in the dog. It is postulated that the heterotopic ossification resulted from the metaplastic change of calcinosis circumscripta lesions.

Subluxation/luxation of the second carpal bone in two racing greyhounds and a Staffordshire bull terrier.

Subluxation of the second carpal bone (C2) in two racing greyhounds, and luxation associated with other carpal injuries in a Staffordshire bull terrier, were diagnosed as causes of thoracic limb lameness. The clinical signs of subluxation were subtle, with local soft tissue swelling and a pain reaction on digital pressure over the dorsal aspect of C2. In contrast, the dog with a complete luxation was very lame, having marked soft tissue swelling with carpal hyperextension and valgus. Diagnosis was made by radiography. Subluxation of C2 was seen as a small, dorsally displaced opacity between the proximal and distal rows of carpal bones on the mediolateral view and, on the oblique view taken in only one case, as a marked dorsal displacement of one-third of the proximal joint surface of C2. In the case of luxation, C2 appeared on the mediolateral view lying dorsal to the radial carpal bone. There was also fracture of C4. Both greyhounds were treated by internal fixation and returned to racing. The Staffordshire bull terrier was treated by pancarpal arthrodesis with a successful outcome.

Accessory carpal bone displacement in two dogs.

The diagnosis and treatment of luxation of the accessory carpal bone in a racing greyhound, and subluxation of the same bone in a lurcher, are described. The injury in the lurcher occurred in both carpi, but on separate occasions. Both dogs had severe thoracic limb lameness with marked carpal swelling. The diagnosis of luxation was obvious from carpal radiographs. The subluxations were difficult to detect on palpation, but were suspected and confirmed on exploratory surgery, which showed an avulsion of the lateral support structures of the accessory carpal bone from the distal ulna. Pancarpal arthrodesis with accessory carpal bone excision undertaken in the greyhound was successful. Following repair of the torn ligaments, the lurcher returned to full activity without lameness before sustaining the same injury to the other carpus. The anatomy of the accessory carpal support structures and the aetiology of the injuries are discussed.

Fractures of the central tarsal bone in eight racing greyhounds.

The case records of eight greyhounds that had undergone a surgical repair of either a type III or type IV fractured central tarsal bone were reviewed. In some cases difficulties were encountered which resulted in less than ideal fixation methods being used, but the fractures healed satisfactorily by intertarsal ankylosis and were radiographically complete after four to six months. For a successful outcome it was not necessary to preserve functional intertarsal joints by interfragmentary reconstruction and compression. The absence of dorsal slab fixation, poor dorsal screw positioning, or loss of the dorsal fragment, had no influence on the results. It took from six months to one year for the dogs to return to racing.

Tears of the palmar superficial fascia in five racing greyhounds and a Labrador retriever.

Tears of the palmar superficial fascia over the palmar extremity of the accessory carpal bone were identified as the cause of lameness in five racing greyhounds and as a coincidental finding in a Labrador retriever with an avulsion of the insertion of the flexor carpi ulnaris tendon. The lameness in the greyhounds was mild and transient, although racing performance was affected. The Labrador retriever was severely lame. In all cases there was a marked soft tissue swelling and a palpable defect in the superficial fascia. One case was managed conservatively and surgical repair was performed in the remaining five cases. The greyhounds returned to successful racing and the Labrador retriever made a complete recovery.

Sprain of the short radial collateral ligament in a racing greyhound.

Severe carpal lameness in a racing greyhound due to a sprain of the straight part of the short radial collateral ligament is described. The dog subsequently developed an enthesiopathy at the origin of the ligament. Treatment was by kennel rest and the dog returned to successful racing.

Enthesiopathy of the short radial collateral ligaments in racing greyhounds.

In a radiographic survey of the carpi of 100 racing greyhounds there was a 14 per cent incidence of enthesiopathy of the origin of the straight part of the short radial collateral ligament. Enthesiopathy was not identified as a clinical problem in any case, nor was there historical evidence of any adverse effect on performance.