Central tarsal bone fractures in the racing Greyhound: a review of 114 cases

A total of 114 central tarsal bone (Tc) fractures, including associated secondary fractures, were identified in 114 racing Greyhounds. The fractures were classified according to a previously described scheme. The type IV Tc fracture, dorsal and medial slab fractures, was most common. A Tc fracture alone, or a Tc fracture with associated fractures of the 4th tarsal bone (T4), calcaneus, or T4 and lateral base of the 5th metatarsal bone were the most commonly observed. The prevalence of secondary fractures increased with the severity of the Tc fracture. Management of Tc fractures involved 3 methods: coaptation, single-screw fixation, and 2-screw fixation. Additional repair was performed as indicated by the presence of concurrent secondary fractures. A total of 71% of the dogs returned to competitive racing.     

Mandibular fracture in a Lhasa Apso with secondary renal hyperparathyroidism

A Lhassa Apso is presented in emergency after having been injured by another dog. It was suffering from a mandibular fracture. The clinical exam revealed generalized and excessive mobility of the whole dentition. Radiographs showed generalized jaw bone demineralisation. A blood sample was analysed and revealed chronic renal disease. We came to the conclusion that this dog was suffering from secondary renal hyperparathyroidism. The hypocalcified bone was so thin that a slight trauma induced the mandibular fracture.     

Effects of isobutyl-2-cyanoacrylate on bone healing

An in vivo evaluation of isobutyl-2-cyanoacrylate as an osseous adhesive was performed to determine its effect on bone healing. Oblique cortical fractures were induced at the tibial-fibular junctions of adult rabbits. Forty-eight fractures were repaired by the use of isobutyl-2-cyanoacrylate and a full cerclage wire. The opposite control fracture was repaired with a full cerclage wire only. One hundred percent of the glued fractures were not united through the glue interface, although normal periosteal new bone formation (secondary bone healing) took place around the glue. One hundred percent of the nonglued fractures healed by secondary bone union. Reactions were not seen in the bone or soft tissue adjacent to the adhesive material.     

Interlocking intramedullary nail stabilisation of a diaphyseal tibial fracture

A closed comminuted diaphyseal tibial fracture in an adult dog was stabilised with a custommade interlocking intramedullary nail. The fracture progressed to union by 14 weeks, by secondary bone healing. The use of interlocking intramedullary nails in human and veterinary orthopaedics is discussed.     

Secondary (classical) bone healing

The principal determinants of the resolution of any wound are the type and extent of injury, the regenerative capacity of the constituent cells, and the extent of damage to the extracellular matrix. As stated previously, in the repair of a fracture, anything other than the final formation of bone tissue at the fracture site represents incomplete healing. Nature has provided bone with a remarkable array of mechanisms by which to effect fracture repair. An understanding of secondary (classical) bone healing is important to prevent any untoward effects that might ensue if an injury were left untreated, to select a form of fracture treatment that would complement nature's mechanisms, and to facilitate the interpretation of sequential radiographs obtained to evaluate the healing process.     

Polyostotic cystic bone lesions in a dog

The clinical, radiological, and pathological features of a polyostotic cystic bone lesion in a 9-month-old Doberman Pinscher are described. The patient was diagnosed as having nutritional secondary hyperparathyroidism at 6 weeks of age and after dietary correction it remained clinically normal until 9 months when there was sudden left hind-limb lameness due to a pathological fracture through a cystic lesion in the distal femur. Radiography revealed additional cystic structures in the metaphyses of the left radius, and left and right tibia. Pseudofractures were associated with two of the cystic lesions.
In some areas the cysts were crossed by trabeculae and in others there were bony ridges on the inner cystic wall. The cavities were lined with flesh-coloured fibrillar material which formed a lacy network extending into cavities. Histologically, multiple small cysts were present adjacent to the larger cavities noted radiographically. The secondary spongiosa and the metaphyseal periosteum were the major abnormal tissue sites. The small cysts appeared to arise in an oedematous and congested metaphyseal spongiosa. The cysts were accompanied by small foci of intense osteoclasis but unattended by compensatory bone production, and the consequent possibility of pseudofractures is an important clinical consideration. Earlier reports demonstrated that resolution of the lesions will follow surgical drainage and curettage of the cystic cavity. Of six cases of polyostotic cystic bone lesions observed in the dog, five were in the Doberman Pinscher breed.     

Treatment of incisive bone fracture in a horse using an acrylic splint

A ventrally displaced incisive bone fracture was diagnosed in a 3-year-old Andalusian stallion. Symptoms included swelling of the lips, dysphagia and ptyalism. External manipulation revealed pain and crepitus in the gingival region of the rostral maxilla. An intraoral examination revealed upper gingival haematomas, misalignment and malocclusion of the incisors (prognathism). A radiograph of the rostral maxilla confirmed ventrally displaced bilateral fractures of the incisive portion of the maxilla rostral to the canine teeth (Triadan 104/204). The fracture was reduced under general anaesthesia. A methylmethacrylate intraoral splint was used to stabilise the fracture. Post operative radiographs confirmed the fracture reduction. Post operative clinical control confirmed the correct position of the splint. No complications were encountered in the post operative period and good stabilisation was obtained. The splint was removed 60 days post operatively. The use of an acrylic intraoral splint successfully stabilised a bilateral, ventrally displaced incisive bone fracture. Normal occlusion was obtained. The use of an acrylic splint may represent a relatively simple, inexpensive and noninvasive technique for the repair of incisive bone fractures rostral to canine teeth in horses.     

Arthroscopic guided repair of a slab fracture of the fourth carpal bone in an 8-month-old thoroughbred horse

An 8-month-old thoroughbred colt presented with sudden onset right forelimb lameness. A radiographic series of the right carpus was performed, and it revealed a slab fracture of the fourth carpal bone and fracture of the proximal part of the third metacarpal bone. Arthroscopically guided repair of the slab fracture of the fourth carpal bone with a 3.5 mm cortex screw and lag screw fixation of the fracture of the proximal part of the third metacarpal bone were performed. The horse started to race at 32 months old and started in 65 races over three years without any trouble associated with the right carpus.     

Ultrasonographic and radiographic assessment of uncomplicated secondary fracture healing of long bones in dogs and cats

OBJECTIVES: To evaluate the use of ultrasonography (US) to detect bone healing in uncomplicated diaphyseal fractures of dogs and cats, and to compare these observations with detection of healing by radiography (RG). STUDY DESIGN: Clinical study. ANIMALS: Dogs (33) and cats (11). METHODS: RG and brightness mode US were used to follow uncomplicated secondary fracture healing. Fractures were examined at admission and then every 2-4 weeks until healed or implant removal. Temporal differences in definitive detection of healed fracture by imaging technique were examined by species, patient age, bone, and fracture type. RESULTS: US images obtained during uncomplicated secondary fracture healing were consistent with images of fracture healing described in humans. Mean time to US diagnosis of a healed fracture (mean 46 days) was significantly shorter than by RG (mean 66 days). Mean time until diagnosis of a healed fracture (US and RG) did not differ significantly between open and closed treatment. Patients 36 months (n=11), but there was no significant difference between the latter 2 groups. Diagnosis of a healed simple fracture by US was significantly quicker than for a comminuted fracture (P<.05), but no difference was noted when using RG. CONCLUSIONS: US can be used to evaluate secondary fracture healing in biologically treated fractures in dogs and cats. US permits detection of a healed fracture earlier than RG. CLINICAL RELEVANCE: Earlier diagnosis of a healed fracture by US can prevent unnecessarily long limb immobilization and allow earlier dynamization.     

Late-onset fracture-associated osteosarcoma in a cat

An 18-year-old male, castrated Domestic Shorthaired cat was presented with the complaint of acute severe lameness of the left pelvic limb. There was no history of trauma, apart from a distal physeal left femoral fracture that had been repaired 17 years previously. Radiology revealed a displaced distal metaphyseal femoral fracture with marked areas of bone lysis and periosteal proliferations. A pathological fracture due to a bone neoplasia was suspected. An amputation with coxofemoral disarticulation was performed. Histopathology confirmed the tentative diagnosis of appendicular osteo-sarcoma. No postoperative complications were encountered and the cat made a full recovery. This case shows an unusual presentation of a late-onset fracture-associated feline osteosarcoma.     

Vestibular syndrome associated with temporohyoid joint fusion and temporal bone fracture in three horses

Acute onset of vestibulocochlear and facial nerve dysfunction due to a stress fracture of the petrous part of the temporal bone was diagnosed in 3 horses. The fracture was secondary to chronic inflammatory changes in the petrous part of the temporal bone and the proximal stylohyoid bone, with fusion of the temporohyoid joint. Bacterial meningoencephalitis was a complicating factor. Treatment resulted in reduction of severity of clinical signs in 2 of the 3 cases, but residual compensated vestibular deficits persisted.     

Omentalisation as adjunctive treatment of an infected femoral nonunion fracture: a case report

A three-year-old male working border collie with an infected femoral nonunion fracture was managed in a two-stage procedure involving debridement and omentalisation, followed by stabilisation with a bone plate and an autogenous cancellous bone graft. Osseous union was documented radiographically 16 weeks after surgery. Telephone follow-up one year later revealed the dog had returned to full working function without evidence of lameness. To the authors' knowledge, this is the first clinical case described in the veterinary literature using omentalisation as an adjunct to the management of an infected, biologically inactive nonunion fracture.     

Excellent long-term clinical outcome in a young athletic dog following surgical complications of a comminuted patellar fracture and patellar ligament rupture

A 1-year-old athletic golden retriever dog was presented for a non-weight-bearing right pelvic limb lameness that occurred during a canicross race. Orthopedic examination revealed pain and inflammation of the right stifle joint. Radiographs showed a traumatic comminuted patellar fracture. Surgery was elected and a midsubstance patellar ligament rupture was also identified. Surgical management consisted of a combination of techniques for patellar fracture fixation and primary patellar ligament reconstruction. All orthopedic implants were removed secondary to implant failure. Postoperative 20-month radiographic follow-up revealed patella alta and non-union of the fracture. However, an excellent clinical outcome was achieved with a complete return to a high activity level.Key clinical message:Surgical stabilization of patellar fractures is usually a significant challenge. A return to apparent normal limb function was achieved in this dog suffering complex patellar fracture with concomitant patellar ligament rupture despite postoperative fracture non-union.     

Ulnar interlocking intramedullary nail stabilization of a proximal radio-ulnar fracture in a dog

Objective: To report use of an ulnar interlocking intramedullary nail for repair of an open highly comminuted fracture of the proximal third of the antebrachium in a dog, caused by gunshot. Study Design: Case report. Animals: 1.5‐year old, 60 kg, neutered male Mastiff. Methods: An ulnar interlocking intramedullary nail was used to stabilize an open comminuted proximal antebrachial fracture and a cast applied for 4 weeks. Results: Union by secondary bone healing occurred in 8 weeks. At 16 weeks, there was advanced remodeling of the radial and ulnar bony callus and fracture lines were no longer evident. Limb use was normal with normal pain free range of motion of the right elbow. Conclusion: Ulnar interlocking nail is a viable alternative treatment for highly comminuted fracture of the proximal third of the antebrachium in dogs.     

Surgical repair of fracture of the os penis in a dog

An eight-year-old male Australian cattle dog cross was presented with complete urethral obstruction secondary to fracture of the os penis which had occurred two years earlier. Obstruction was associated with callus and fibrous tissue proliferation compressing the urethra at the fracture site. The problem was satisfactorily resolved by removing excess bone and fibrous tissue and stabilising the fracture with a stainless steel finger plate.     

Standing repair of a proximal,incomplete, articular fracture of the third metatarsal bone

A 5-year-old National Hunt Thoroughbred mare presented with sudden onset left hindlimb lameness after race training on the gallops. Clinical examination revealed a marked painful reaction over the proximal metatarsal region but no other obvious abnormalities were detected. Survey radiographs at the yard did not reveal any abnormalities. Nuclear scintigraphic examination 3 days after injury revealed focal marked increased radiopharmaceutical uptake in the proximal metatarsal region. Subsequent radiography revealed an incomplete, articular fracture of the proximal left third metatarsal bone. Repair of the fracture using 3 × 4.5 mm cortical screws placed in lag fashion was performed under standing sedation following perineural analgesia. Follow-up radiographs demonstrated progressive healing of the fracture. The mare returned to race training 8 months after the fracture was repaired and raced successfully 12 months post injury.     

Effect of Gelatin Hydrogel Sheet Containing Basic Fibroblast Growth Factor on Proximal Sesamoid Bone Transverse Fracture Healing in the Horse

Our objective in this study was to examine the effect of gelatin hydrogel (GH) sheets containing basic fibroblast growth factor (bFGF) on healing of proximal sesamoid bone transverse fractures in the horse. Ten healthy adult Thoroughbreds were used. The lateral proximal sesamoid bone of the left forelimb and the medial proximal sesamoid bone of the right forelimb were osteotomized, while the horses were under general anesthesia, and subsequently repaired by lag screw fixation using a single 4.5-mm cortical screw. A GH sheet containing 100 μg of bFGF was then sutured to the synovial membrane adjacent to the osteotomized proximal sesamoid bone. In the control group, the fracture was fixed with a lag screw, and the articular capsule was sutured. Fracture healing was assessed by radiographic examination once a week for 16 weeks after the operation. Radiographic examination of bone healing revealed significantly lower demineralization of the fracture line in the GH sheet-treated group than in the control group. The rate of demineralization of the fracture line in the GH sheet-treated group was significantly lower than that in the control group at 2, 4, and 8 weeks after the operation. In this study, we demonstrated that the use of a GH sheet containing bFGF promotes healing of proximal sesamoid bone fracture in the horse. Therefore, it is believed that this treatment strategy would be useful for quick recovery from bone fracture in the horse.     

Computed tomography assisted repair of a central tarsal bone slab fracture in a horse

A 13‐year‐old Quarter Horse gelding was presented for repair of a central tarsal bone fracture. Radiographs showed a single large nondisplaced sagittal slab fracture; however, computed tomography (CT) revealed an additional small, displaced central tarsal bone fragment. The complex fracture was repaired, under the same anaesthetic period as the CT examination, using the CT hard copies images, intraoperative fluoroscopy and radiographs. The horse recovered well and after rehabilitation showed no residual lameness at work. Computed tomography was instrumental in achieving precise screw placement and successful fracture repair.     

Distal metacarpal sequestration in a bison.

A 2-year-old 400-kg female American bison was admitted for evaluation and treatment of an open fracture of the right metacarpal bones 3 and 4. Radiography revealed osteolysis of the distal metaphysis and epiphysis, with extensive bony callus formation along the dorsoproximal and proximomedial aspects extending distally to the proximomedial aspect of the proximal phalanx. Evidence of periosteal or bony proliferation at the fracture site or along the distal segment of the third and fourth metacarpal bones was not visible, suggesting that the distal fracture fragment was becoming a sequestrum. Treatment consisted of soft tissue debridement and placement of the limb in a full-limb cast. The cast was changed every 4 weeks until the sequestrum was removed and the bone healed. It is rare for the distal half of a long bone to sequester following fracture. Additionally, it is remarkable that the sequestrum served as a buttress, which prevented collapse of the bone until the sequestrum was replaced by functional bony callus.     

Repair of a delayed-union stress fracture of the dorsal cortex of a metacarpal bone in a horse

A delayed union metacarpal stress fracture was repaired in a horse, using lag-screw fixation in conjunction with dc electrical stimulation. Twelve weeks after surgery, radiographic and scintigraphic evaluations revealed that the fracture line was not discernible and that there was a decrease in radiopharmaceutic uptake, as compared with that in previous bone imaging studies. In this horse, DC stimulation of a delayed union stress fracture in a bone resulted in a healing pattern similar to that in human beings with delayed union fractures when treated with electrical stimulation.