Fixation of Radius and Ulna Fractures in the Immature Dog and Cat A Review of Popular Techniques and a Report of Eight Cases Using Plate Fixation

External immobilization and traditional pinning techniques for radius and ulna fractures in immature animals are associated with complications. Prolonged splinting and casting risks postural hyperextension. Pinning techniques may injure growing bones and joints. Eight cases are presented in which fractures of the radius and ulna in immature animals were treated with plates and without external splints. Ail fractures healed without iatrogenic injury to the growing bones and joints and without hyperextension problems of fracture disease. Plating proved a highly effective method of treatment for these fractures in growing animals, avoiding complications and the problems associated with external splinting and traditional pinning techniques.     

Clinical application of an external fixator in the repair of bone fractures in 28 birds

The repair of seven tibiotarsal fractures, three humeral fractures, three tarsometatarsal fractures, two femoral fractures and 13 radial and ulnar fractures with a tubular external fixator system was evaluated prospectively in 10 common pigeons (Columba livia), 11 psittacine birds, six birds of prey and one Bali starling (Leucopsar rothschildii). The fixations included type 1, type 2 and intramedullary tie-in methods, and the fractures healed in all but three cases. A comparison of the weight of different connecting bars showed that the external fixation system and polymethylmethacrylate are the lightest available systems and that there was no clinically relevant difference between them.     

Tibial fractures

Tibial fractures are common in small animal practice. As with other appendicular fractures, the patient's age, fracture location, and fracture type must be considered thoroughly. While methods for tibial fracture repair are similar to those used for appendicular fractures elsewhere, there are some unique considerations, both anatomically and functionally, that must be contemplated before repair. The following article will review the incidence of tibial fractures, tibial fracture types, and options for tibial fracture management and treatment. The use of external fixators, orthopedic bone plates, open reduction with internal fixation (ORIF), and external coaptation will be discussed. An emphasis will be placed on the most common types of tibial fractures, as well as those best suited for repair by general practitioners of veterinary medicine. Three case based examples will follow the overview.     

External skeletal fixation for stabilisation of comminuted humeral fractures in cats

Thirteen feline humeral fractures were stabilised using external skeletal fixation alone or in combination with supplementary devices. Eleven of the 13 fractures healed. Pins placed in the distal humerus should be angled to avoid the supracondylar foramen and radial nerve. An intramedullary pin in combination with external skeletal fixation is indicated for mildly comminuted reconstructable fractures. For severely comminuted humeral fractures, closed application of an external skeletal fixator may be preferable to open reduction and internal fixation to provide healing and is recommended as an alternative to amputation.     

Incidence of and predisposing factors for nonunion of fractures involving the appendicular skeleton in cats: 18 cases (1998-2002)

OBJECTIVE: To identify the most common sites of and possible predisposing factors for nonunions in cats with fractures of the appendicular skeleton. DESIGN: Retrospective study. ANIMALS: 344 cats treated for fractures between 1998 and 2002, 18 of which developed nonunions. PROCEDURES: Information collected from the medical records included signalment; type of trauma; fracture location, orientation, and type; degrees of displacement and comminution; treatment; and outcome. RESULTS: The tibia and proximal portion of the ulna were identified as the most common sites for nonunions. Factors significantly associated with development of a nonunion included age, body weight, affected bone, fracture type, degree of comminution, and fixation type, with older cats, heavier cats, cats with fractures of the tibia or proximal portion of the ulna, cats with open fractures, cats with comminuted fractures, and cats with fractures stabilized with a type II external skeletal fixator being significantly more likely to develop a nonunion. Eleven of the 18 cats with nonunions had a successful outcome following treatment of the nonunion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that in cats, fractures involving the tibia and proximal portion of the ulna are more likely to develop nonunions than are fractures involving other sites but that many factors may increase the risk of nonunion. Use of excessively large and rigid type II external skeletal fixators may be associated with development of nonunions; however, type II external skeletal fixators were commonly used to stabilize fractures in sites predisposed to nonunion.     

Fractures and luxations of the vertebral column.

External fixation of the vertebral column is indicated to treat fractures of the caudal lumbar spine, open fractures where vertebral osteomyelitis is present or likely to occur, and vertebral fractures not easily stabilized by internal fixation alone (e.g., compression fractures, fractures including spinous processes, and articular facets). Advantages of external fixation of caudal lumbar fractures, especially in combination with dorsal fixation devices, include the following: Fracture fixation does not preclude dorsal decompression; fixation devices need not be applied directly to the fractured vertebrae; and the combined technique provides dorsal and ventral vertebral fixation, which is more stable than dorsal fixation alone. Although external fixation is not applicable to all vertebral fracture/luxations in small animals, it provides additional points of fixation for rigid stability. Animals with vertebral fracture/luxations treated with an external fixation device have tolerated the external portion well. Development of additional applications for this method of vertebral fracture repair seems warranted.     

Treatment of distal diaphyseal fractures using hybrid external skeletal fixation in three dogs

Stabilisation of distal diaphyseal/metaphyseal fractures or osteotomies of the tibia and the radius is challenging due to the small fragment size, with innovative implants and external skeletal fixation systems described for their management. Hybrid external skeletal fixation is a novel external fixation system for use in small animals. This case series describes the management of distal diaphyseal fractures with IMEX-SK hybrid external skeletal fixation in three canine patients. Fracture healing was achieved in all cases, with frame removal after 5 to 10 weeks. Minimal complications were encountered in two cases. IMEX-SK hybrid external skeletal fixation constructs provide the veterinary surgeon with another option in the management of distal diaphyseal/metaphyseal fractures.     

Metatarsal III fractures in the racing greyhound

During a five-year period, six single stress fractures of metatarsal Iii fractures were diagnosed in five greyhounds. All cases occurred while racing and without external trauma. Treatment by external support had previously been unsuccessful in three cases. However, surgical treatment permitted a prompt return to racing in all cases treated. The aetiopathogenesis of these fractures, the relative importance of the functional anatomy of the canine hock and the practice of racing greyhounds around tight curves are discussed.     

Use of external skeletal fixators in the repair of femoral fractures in cats

This paper reports the results of fixation of 35 femoral fractures in cats using an external skeletal fixator alone or in combination with supplementary devices. All the fractures healed. The average time to fixator removal was eight weeks and two days. The external skeletal fixator offers a method of repairing many types of femoral fractures in cats allowing sound orthopaedic principles to be maintained and producing a successful outcome.     

External coaptation for the treatment of long bone fractures in cattle: a retrospective study of 35 cases (1996-2001)

The objective of this retrospective study was to report the history, signalment, frequency, types, complications, and long-term outcome of long bone fractures in cattle treated using external coaptation techniques. The sex, age, breed, history, physical examination findings, and radiographic findings were recorded. Of 35 cases with long bone fractures treated using external coaptation, 31 were discharged alive. The mean hospitalization time for these cattle was 2 days. Six to 12 months after treatment, 26 (84%) cases were considered satisfactorily healed. It was concluded that cattle with long bone fractures could be treated successfully using external coaptation with minimal effect on productivity.     

Long-bone fractures in llamas and alpacas: 28 cases (1998–2008)

Treatment and outcome of camelids with long-bone fractures are described. Medical records (1998–2008) of camelids (n = 28) with long-bone fractures were reviewed for signalment, time to presentation, fracture type, method of repair, duration of hospitalization, and post-operative complications. Follow-up information was obtained via telephone interviews with owners. Mean age and weight at presentation were 3.4 years and 56.3 kg, respectively. Twenty-six fractures were treated with internal fixation (n = 11), external fixation (n = 10), combination of internal and external fixation (n = 3), amputation (n = 1), and external fixation followed by amputation (n = 1). Long-term follow-up information was obtained for 19 of the 26 animals. The post-operative complication rate was 23% and owner satisfaction was high. Animals with open fractures were more likely to experience complications. Internal fixation was associated with superior alignment and outcome. Internal fixation techniques should be recommended for camelids.     

Management of 49 antebrachial and crural fractures in dogs using circular external fixators

Objectives : To evaluate frame constructs, postoperative fracture reduction, postoperative care, complications, treatment duration and outcome of circular external fixation for management of 49 antebrachial and crural fractures in dogs. Methods : Medical records of dogs that underwent surgery with circular external fixation were examined for fracture location, frame configuration, postoperative fracture reduction, treatment duration, complications and outcome. Results : Forty‐nine fractures in 48 dogs were stabilised using circular external fixation. Frame removal occurred on average 61 days after surgery (median±sd, 52±30 days). Minor complications were observed in 35 cases (71 per cent) and major complications in seven (14 per cent). Radiographic outcome at frame removal was judged as excellent in 18 cases (37 per cent), as good in 26 (53 per cent), as fair in four (8 per cent) and poor in one (2 per cent). After frame removal, one fracture was stabilised with a plate, and eight patients were lost to follow‐up. Functional and cosmetic outcome at follow‐up was judged as excellent in 32 cases (80 per cent), good in seven (18 per cent) and fair in one (2 per cent). Clinical Significance : Circular external fixation can effectively treat antebrachial and crural fractures in dogs, even geometrically complex fractures. Minor complications are frequent but easily managed in most instances. Healing time is comparable to that of other external fixation methods.     

Radial and Tibial Fracture Repair with External Skeletal Fixation: Effects of Fracture Type, Reduction, and Complications on Healing

Twenty-eight consecutive fractures of the canine radius and tibia were treated with external skeletal fixation as the primary method of stabilization. The time of fixation removal (T1) and the time to unsupported weight-bearing (T2) were correlated with: (1) bone involved; (2) communication of the fracture with the external environment; (3) severity of the fracture; (4) proximity of the fracture to the nutrient artery; (5) method of reduction; (6) diaphyseal displacement after reduction; and (7) gap between cortical fragments after reduction. The Kruskal-Wallis one-way analysis of variance was used to test the correlation with p less than .05 set as the criterion for significance. The median T1 was 10 weeks and the median T2 was 11 weeks. None of the variables correlated significantly with either of the healing times; however, there was a strong trend toward longer healing times associated with open fractures and shorter healing times associated with closed reduction. Periosteal and endosteal callus uniting the fragments were observed radiographically in comminuted fractures, with primary bone union observed in six fractures in which anatomic reduction was achieved. Complications observed in the treatment of these fractures included: bone lysis around pins (27 fractures), pin track drainage (27 fractures), pin track hemorrhage (1 fracture), periosteal reaction around pins (27 fractures), radiographic signs consistent with osteomyelitis (12 fractures), degenerative joint disease (2 dogs), and nonunion (1 fracture). Valgus or rotational malalignment resulted in 16 malunions of fractures. One external fixation device was replaced and four loose pins were removed before the fractures healed. One dog was treated with antibiotics during the postoperative period because clinical signs of osteomyelitis appeared.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fracture repair with transfixation pins and fiberglass cast in llamas and small ruminants

Transfixation pinning with fiberglass casting is an effective and adaptable method of longbone fracture fixation in llamas and small ruminants. Treatment of fractures in 7 limbs of 4 llamas and 2 small ruminants with this technique are described. Steinmann pins are placed transcortically proximal, and if necessary, distal to the fracture. The pin ends and limb are encased in fiberglass cast material. The cast is strong enough in animals of this size to eliminate the need for external frames or connecting bars. Severely comminuted fractures and fractures near joints are especially suited to fixation with this technique. Complications encountered in these cases included loosening of pins and one delayed union. All fractures healed to permit full use of the limb.     

Dowel pinning for feline metacarpal and metatarsal fractures.

The goal of this retrospective study was to describe dowel pinning, and to compare the results of osteosynthesis and external coaptation of metacarpal and metatarsal fractures in cats. Evaluation of the medical records of 351 cats yielded 63 cats treated with dowel pinning, 35 cats treated with external coaptation and 14 cats treated with both methods within the same limb. All of the cats had been re-evaluated at an average of 2.8 years (six months - 15 years) postoperatively. Dowel pinning was superior to external coaptation when all fractured bones of a limb could be pinned. When internal fixation of multiple fractures was not feasible in all fractured bones due to comminution or fragments that were too short to pin, the outcome was not significantly different from cases treated with external coaptation alone. Malunion was seen in 16% of fractured bones in cats treated with external coaptation and occurred secondary to implant bending in 3% of fractured bones treated with dowel pinning. The latter refers to one operated cat, which had four metacarpal fractures in the same limb. Radiographs taken at re-evaluation showed implant migration within the medullary canal in two cats, although neither showed any signs of non-union or lameness. Non-union was seen in one operated cat, in which the fracture (MC IV) could not be completely reduced with a K-wire. Osteomyelitis did not occur. Dowel pinning is an easy, inexpensive and effective technique for repair of metacarpal and metatarsal fractures in cats.     

Fractures of the humerus.

A single or double bar, type I, unilateral external fixator can be used as primary or ancillary treatment for repair of many humeral fractures. Treatment of contaminated and comminuted fractures with external skeletal fixation provides rotational stability and axial alignment, access for wound management and bone grafting, and avoidance of vascular compromise by surgical invasion. In addition, the combination of external and internal (IM pins, cerclage wires, plates) fixation can provide greater initial fracture stability and subsequent dynamization or loading of bone (as the fixator is removed) than either of the systems used individually.     

A retrospective clinical study of the fractures and luxations of the mandible in the cat

Twenty-six cases of mandibular fractures and luxations are reviewed. Mandibular trauma was due to car accidents (46%) and falls from great heights (23%). Cardiovascular shocks (40%), thoracic injuries (23%), epistaxis (30%), cleft palates (19%), subconjunctival hemorrhages (15%), broken canines (15%), concussions (15%), maxillary fractures (12%) were the most frequently encountered associated problems. Of the 26 cats, 22 had symphyseal fractures, 6 mandibular body fractures, 4 ramus fractures (3 of which were articular) and 6 had temporo-mandibular luxations. Open reduction and internal fixation was performed in 21 cases, surgery being indicated for unstable symphyseal and body fractures, the rostral body fractures being the most challenging to repair. Conservative therapy and ancillary treatment methods such as external coaptation and pharyngostomy were used for the fractures of the ramus. Six temporo-mandibular luxations associated with mandibular fractures in 5 cases were reduced under anesthesia. Good dental occlusion and mandibular function was obtained in the 24 treated cases.     

Orthopedic clinical techniques femur fracture repair

Femur fractures occur commonly in cats and dogs following substantial trauma. Fractures of the femur may be categorized as capital physeal, femoral neck, trochanteric, subtrochanteric, diaphyseal, supracondylar or condylar or distal physeal. Most femur fractures are closed due to the heavy overlying muscle, unless due to a penetrating injury such as a gunshot wound. Femur fractures are generally not amenable to conservative repair, and some kind of internal fixation is generally required. Implant systems suitable for repair of femur fractures include bone plates, interlocking nails, plate-rod construct, lag screws, pins and wires and external fixators. Fractures may be repaired using anatomic reduction and rigid fixation or using the principles of biologic osteosynthesis. Biologic osteosynthesis is particularly effective for highly comminuted fractures because vascular supply and soft tissue attachments to bone fragments are preserved, speeding the formation of bone callus. Articular fractures should be anatomically reduced and rigidly stabilized to reduce the chance of progressive osteoarthritis.     

External Skeletal Fixation of Comminuted Maxillary Fractures in Dogs

An external skeletal fixation technique that was effectively applied on comminuted maxillary fractures is described. With this method, pairs of Kirschner wires and/or Steinman pins were seated into the fracture fragments and the exposed cut ends of the pins were embedded into an acrylic bridge. Excellent stabilization of the fractures was effected and normal oral alimentation was resumed immediately. Healing of the fractures usually occurred within two or three months and the pins were then removed. Three representative cases are presented.     

Lateral fabellar fractures in the dog: A review of eight cases

Fractures of the lateral fabella were recorded in seven medium or large breed dogs. Six dogs had unilateral fractures and one had bilateral fractures. The fractures appeared to occur spontaneously, without external trauma. Four fractures were managed conservatively and four were treated by surgical removal of the fracture fragments. Both treatments were successful in resolving the lameness.