Treatment of fractures in avian species.

External fixation, with coaptation or Kirschner-Ehmer splints, is a viable treatment for many fractures in captive and wild birds. Important considerations in selecting a device are the weight and size of the device, location of the fracture relative to joints, and prognosis associated with location of the fracture(s). A variety of materials, not limited to traditional medical materials, may be used in coaptation splinting. Straws, plastic spoons, and rubber balls can serve as effective splints. Type I and II Kirschner splints are typically used in birds, although large birds may require a type III splint on leg fractures. The most useful configuration for wing fractures is the type Ia single bar splint using epoxy or acrylic for the connecting bar. This splint is lightweight, positioned close to the patient, and stable for most fractures. The type II splint is an excellent choice for leg fractures at the level of the tibiotarsus and below. The destructive character of psittacines requires all splints be protected from the beak of the bird. Clavicular-furcular and coracoid fractures in small birds may be effectively managed with coaptation splinting. In birds over 400 g body weight, open reduction is needed for best results. Since fractures of the foramen triosseum are usually not surgically repairable, they can be stabilized with coaptation splints. Although humeral fractures may be managed with coaptation in some circumstances, firm stabilization with a type I Kirschner-Ehmer splint or internal fixation is best. Single bone fracture(s) of the radius or ulna can usually be managed with minimal treatment, brailling, or figure-of-eight wraps. Fractures of both the radius and the ulna require a type I Kirschner-Ehmer splint for internal fixation. Coaptation splinting alone is usually indicated for carpal or carpometacarpal injuries. Femoral fractures in small birds may be managed with coaptation splinting, although fractures in large birds or unstable fractures require internal fixation or a type I Kirschner-Ehmer splint. Tibiotarsal fractures, in many species, may be managed with internal fixation or a type II Kirschner-Ehmer splint. Tarsometatarsal fractures can be cast or stabilized with a type II Kirschner-Ehmer splint. Phalangeal fractures are best managed with coaptation splinting.     

External skeletal fixation in the management of equine mandibular fractures: 16 cases (1988-1998)

Fifty-three cases of equine mandibular fractures were managed surgically from 1988-1998, of which 16 (30%) were repaired by external skeletal fixation (ESF). Three surgical methods were utilised: transmandibular 4.76 or 6.35 mm Steinmann pins incorporated into fibreglass casting material or nonsterile dental acrylic (methyl methacrylate - MMA) bars reinforced with steel; transmandibular 9.6 mm self-tapping threaded pins +/- 4.76 or 6.35 mm Steinmann pins incorporated into MMA bars reinforced with steel; and 4.5 mm or 5.5 mm ASIF cortical bone screws incorporated into MMA bars reinforced with steel or a ventral MMA splint. Fourteen horses were presented to the hospital for fixator removal at an average of 56.2 days. At removal, fractures were stable and occlusion of incisor and cheek teeth was considered adequate. Complications of the procedure occurred in 3 horses. Two horses with persistent drainage and ring sequestra from pin tracts required curettage 4 or 5 months after ESF removal. A third horse required replacement of the original fibreglass ESF with MMA bars to regain access to open, infected wounds. Another horse required removal of the second premolar at the time of fixator removal because the tooth root had been damaged in the original injury. ESF for the surgical management of mandibular fractures in horses has produced good results, with incisive and cheek tooth alignment reestablished in all horses. Horses that were managed via ESF had a rapid return to full feed and did not require any supplementation via nasogastric tube or oesophagostomy to maintain bodyweight or hydration status.     

The Kirschner-Ehmer splint in small animal orthopedics

The Kirschner-Ehmer splint can be used to treat open, infected or highly comminuted fractures, gunshot fractures, nonunions, delayed unions, mandibular fractures and angular deformities in association with osteotomy, as well as to immobilize joints and as an adjunct to other fixation devices. After the fracture is reduced, 2-4 percutaneous pins are inserted with a Jacobs hand chuck through one or both cortices at 45-60 degrees to the longitudinal axis of the bone and attached to a connecting bar with clamps. Complications are minimized by not inserting the pin through large muscle masses, the fracture hematoma, large blood vessels or the incision line, avoiding encroachment of soft tissue with the clamps, and restricting the animal's activity during healing.     

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.     

Influence of an interdental full pin on stability of an acrylic external fixator for rostral mandibular fractures in dogs

OBJECTIVE: To determine total stiffness and gap stiffness of an external fixation system in a canine mandibular fracture gap model incorporating a full interdental pin as the only point of rostral fixation in a bilateral type-I external fixator. SAMPLE POPULATION: 10 canine mandibles. PROCEDURE: Bilateral mandibular ostectomies were performed between premolars 3 and 4. A type-I external fixator incorporating a full interdental pin was placed to stabilize a 0.5-cm fracture gap. Four pin configurations (intact mandibular bodies with fixator; ostectomized mandibular bodies and complete fixator; ostectomized mandibular bodies with caudal pins of rostral fragment cut; ostectomized mandibular bodies with all pins of rostral fragment cut) were tested in dorsoventral bending 5 times on each mandible. The full interdental pin remained intact in all configurations. Total stiffness and gap stiffness were determined for each configuration on a materials testing machine. RESULTS: Total stiffness of intact mandibles was significantly greater than that of ostectomized mandibles, regardless of external fixator configuration. However, total stiffness and gap stiffness were not significantly different among different external fixator configurations applied to ostectomized mandibles. CONCLUSION AND CLINICAL RELEVANCE: External fixator configurations with only the full interdental pin engaging the rostral fragment were as stiff as configurations that had 2 or 4 additional pins in the rostral fragment for the applied loads. External fixators for rostral mandibular fractures may be rigidly secured with rostral fragment implants applied extracortically, avoiding iatrogenic trauma to teeth and tooth roots.     

Transarticular application of external skeletal fixation.

External skeletal fixators provide a useful alternative to external coaptation techniques for immobilization of joints in selected patients. This is especially true when the orthopedic injury involves an open wound requiring daily treatment. Devices such as the K-E splint, the Rudy external fixator boot, and acrylic frame fixators are economical and effective for transarticular fixation in small animal patients. Clinical indications for these techniques have included fixation of tibial or radial fractures with a short distal fragment; arthrodesis of the elbow, carpus, stifle, or tarsus; protection of Achilles tendon repairs; protection of collateral ligament repairs of the tarsocrural joint; and protection when multiple ligaments of the stifle joint have been reconstructed. Use of contoured rods has facilitated transarticular application of type II Kirschner-Ehmer splints. Use of acrylic frames and the Rudy boot technique have extended safe use of transarticular external fixation to extremely small patients not accommodated by the Kirschner system alone. An understanding of the advantages and disadvantages inherent in each of these techniques is critical to proper selection of the best method for a given patient. Attention to the basic principles of pin selection, pin insertion, and frame design are needed for successful execution of the chosen technique.     

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.     

Instrumentation for external fixation.

External skeletal fixation is a very useful technique for managing many orthopedic problems in veterinary practice. The Kirschner apparatus has been the most widely used fixator for many years in veterinary orthopedics because of its versatility, simplicity, and economy in use. The medium-sized device has the widest indications and is easiest to begin with. The small size can be acquired later for use on cats and small dogs. The new "raised thread" fixation pin designs improve bone-pin integrity and can be used in combination with nonthreaded pins to decrease the incidence of postoperative complications and for economy. Acrylic-pin external fixators are particularly useful for treatment of mandibular fractures and transarticular application since they allow nonlinear placement of fixation pins in highly contoured bones. A commercial system, currently being developed, will have all the equipment and materials necessary for their application in a convenient kit. Circular fixators (Ilizarov design) use thin K wires placed under tension to replace rigid fixation pins. Their unique adjustability characteristics make them useful in the treatment of limb deformity and shortening. Many other human fixators can be used for veterinary application if the basic principles of fixators are followed. Instrumentation required for external fixator application include a pin driver, pin cutter, and wrenches. Although surgical versions of these materials are available, less expensive alternatives are available using gas sterilization instead of autoclaving. The use of selected orthopedic instrumentation such as a periosteal elevator, bone clamps, and curets will facilitate fracture management.     

Internal Skeletal Fixation Using a Kirschner Apparatus for Stabilization of Fracture/Luxations of the Lumbosacral Joint in Six Dogs: A Modification of the Transilial Pin Technique

A technique using a modification of the transilial pin technique for stabilization of fracture/ luxations of the lumbosacral joint was performed in six dogs. This technique used an internal skeletal fixator composed of two transilial pins secured with two double fixator clamps. Collapse (shortening) of the seventh lumbar vertebra (L7) was observed in five dogs without compromise of the vertebral canal. Kirschner wires placed across the articular facets as supplemental fixation devices migrated to the subcutaneous tissues in two dogs and were easily removed. Migration of the internal fixators was not observed during healing; vertebral canal dimensions were maintained in all cases, and the internal fixators were not removed after resolution of fracture healing. All fractures were healed within 6 to 12 weeks of surgery without evidence of pain, neurologic impairment, or long-term complications.     

Mandibular fracture repair in a harbor seal

A 30-year-old captive female harbor seal (Phoca vitulina) bit down upon a metal ring within a hoop-net normally used to assist in securing the seal for routine physical examination. Radiographic examination performed under general anesthesia revealed a unilateral closed fracture of the rostral left mandible between the first and second premolar teeth. The rostral fragment was displaced ventrally and slight laxity of the mandibular symphysis was noted. The fracture was repaired surgically using an oral dental acrylic splint incorporating circumferential mandibular cerclage wire. The mandibular symphysis was stabilized using interdental wire between the right and left canine teeth. The fixation device was removed following evaluation of radiographs that showed signs of bony union 12-months postoperatively.     

Principles of long bone fracture management.

The fixation of fractures in which one of the following primary devices is used: IM pins, bone plates, external skeletal fixators, can benefit from the additional application of any number of secondary devices. The secondary devices include cerclage, hemicerclage, or interfragmentary wires, skewer-pins, screws, and external skeletal fixators. These are indicated to facilitate the repair and eliminate the forces acting on the fracture site. A complete understanding of all the methods of fixation facilitates the selection of the proper implant or combination of implants. This information must be combined with the knowledge of how each device is most appropriately used depending on both the fracture type and fracture location. Taking into consideration all of these factors helps ensure that fracture healing occurs in the shortest possible time with the fewest complications. The ultimate goal of obtaining a full return to function may thereby be achieved.     

History of external skeletal fixation.

The concept of external skeletal fixation was introduced by Malgaigne in 1840, with a spike driven into the human tibia that was held by a strap encircling the limb. The first readily available external fixator, the Parkhill clamp, appeared in 1897. By the 1920s, a number of adaptations of pins or screws inserted into bone fragments for external control of reduction and fixation had been published. Important developments in that era were triangular half-pin units and anchoring bone pins in both cortices. The Stader splint, which was the first half-pin splint to provide reduction as well as fixation, was used by surgeons in the U.S. Navy during World War II. The Kirschner-Ehmer splint, a veterinary modification of the Anderson splint for humans, was introduced in 1947. Popularity of external skeletal fixation declined in the 1950s because of poor results that may have been caused by errors of application. Improvements in fixator configurations and the skill and judgment of surgeons led to the current acceptance of the method.     

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.     

Treatment of open, delayed union, and nonunion fractures with external skeletal fixation.

ESF is useful in treatment of open fractures and delayed union and nonunion fractures. The fixation pins can be placed away from the fracture site to avoid disruption of blood supply. The appliance is well tolerated and inexpensive, and many of the parts can be reused. Adjustment of the splint is possible to permit correction of stabilization for optimal results. Gradual reduction of frame rigidity improves the quality of healing by increasing the stress on the bone. As stiffness of the healing fracture increases, return of limb function occurs. Early fixator removal reduces patient morbidity and permits a return to normal activity.     

Dental Composite for the Fixation of Mandibular Fractures and Luxations in 11 Cats and 6 Dogs

Twenty-one mandibular fractures in 11 cats and 6 dogs were repaired during a 20-month period. A new technique using dental composite was used to stabilize the mandible. The canine teeth were pumiced, acid etched, and aligned with dental composite, leaving the mouth opened approximately 1 cm. Six weeks after surgery the composite was removed so that radiographs of the mandible could be made with the animal under general anesthesia. In 1 dog in which the fracture had not healed, the composite was replaced. The composite broke before 6 weeks in 8 animals; 2 required replacement of the dental composite. There were no other complications. The median time for fracture healing was 6 weeks. All fractures healed with anatomic dental occlusion. The advantages of this technique are that no further damage is caused to the teeth or to the blood supply of the bone, the occlusion is anatomic, dermatitis (which is seen with tape muzzles) is not a complication, and the technique is easy to use in brachycephalic breeds, cats, and animals with poor bone quality. The limiting factor of this technique is that it does require four salvageable canine teeth. This repair technique is still a viable option even if one or more of the canine teeth are fractured. Dental composite stabilization is fast, easy, inexpensive, and, in our series, it was 100% effective for the repair of mandibular fractures.     

Long-term results of bovine mandibular fractures involving the molar teeth

OBJECTIVE: To evaluate postoperative complications and long-term outcome of simple mandibular fractures involving the molar teeth in cattle. ANIMAL POPULATION: Seventeen cattle with mandibular fractures involving the molar teeth with disruption of the occlusal surface. METHODS: Treatment consisted of application of AO/ASIF-Pinless External Fixators (Synthes, Paoli, PA) in 14 cows, interdental wire stabilization in 1 cow, and conservative treatment in 2 cows. Long-term outcome was determined by telephone contact with the owners, and whenever possible, cows were reevaluated by physical, intraoral, and radiographic examination of the fracture site. RESULTS: Loosening of the fixation device (4 cattle) and bone sequestration (11 cattle) were the most commonly encountered complications. Oral incontinence during rumination was a minor complication in 1 cow. The mean (+/- SD) time the cattle were in production was 26 (+/- 14) months, with 10 cows still alive at follow-up examination; 9 cows were reevaluated. On intraoral examination there was a step in the occlusal surface at the level of the healed fracture site in 3 cows, wave and shear mouth formation in 3 cows, and enamel point formation in 1 cow. Radiographically, all the reevaluated fractures had healed, and there were no signs of tooth root infection. CONCLUSIONS: Complications during healing were bone sequestration and loosening of the fixator. None of the cows was removed from production because of fracture-associated complications, but decreased milk yield occurred in 2 cows. Tooth abnormalities developed in 6 cows, but function of the mandible was not altered. CLINICAL RELEVANCE: Mandible fractures involving the molar teeth carry a good prognosis for return to normal function. Radiographic follow-up is necessary to detect bone sequestration.     

Treatment of inherently unstable open or infected fractures by open wound management and external skeletal fixation

OBJECTIVES: To assess the use of external skeletal fixation with open wound management for the treatment of inherently unstable open or infected fractures in dogs. METHODS: A retrospective review of 10 cases. RESULTS: Fracture stabilisation and wound management required only a single anaesthetic, and despite the challenging nature of these injuries, the final outcome was acceptable or good in every case. However, minor complications associated with the fixator pins were quite common, and two dogs developed complications which required additional surgery. CLINICAL SIGNIFICANCE: Open management of wounds, even when bone was exposed, proved to be an effective technique, and external skeletal fixators were usually effective at maintaining stability throughout an inevitably extended fracture healing period.     

The use of a modified Kirschner—Ehmer apparatus in avian fracture repair

A modified Kirschner-Ehmer apparatus using hoof acrylic as the stabilizing bar was used for fracture fixation in a series of birds. Adequate reduction and stabilization were achieved in most birds. Complications that developed in some birds were life threatening, emphasizing the need for medical management prior to surgical intervention in avian species.     

Placement of Multiple Full Pins for External Fixation Technique and Results in Four Dogs

A technique using a third bar and guide clamp was developed to permit reduction and stabilization of distal limb fractures with full pins and two connecting bars, one on each side of the bone. The system uses only single Kirschner clamps. Four distal limb fractures were stabilized using this technique. Closed reduction was used in three dogs to avoid devitalization of fragments and avoid contamination of a closed fracture. The fracture site stability achieved with this configuration allowed early return to weight bearing and rapid bone healing.