Circular external skeletal fixation stabilization of antebrachial and crural fractures in 25 dogs

Fracture stabilization using circular external skeletal fixation was evaluated in 14 dogs with antebrachial fractures and 11 dogs with crural fractures. Most dogs were consistently weight bearing on the stabilized limb by 3 days following surgery. Although all dogs developed minor wire/pin tract inflammation and eight dogs developed major wire/pin tract inflammation, postoperative lameness was not consistently associated with wire/pin tract complications. Fractures in 23 dogs achieved radiographic union (mean +/- standard deviation [SD], 61 +/- 21 days; median, 57 days) without additional surgery; two dogs required restabilization of their fractures with linear fixators. Twenty of the 21 owners that could be contacted felt their dog had no (n=15) or only a mild (n=5) intermittent lameness at the time of final, long-term (mean +/- SD, 37 +/- 17 months; median, 42 months) assessment.     

Management of humeral and femoral fractures in dogs and cats with linear- circular hybrid external skeletal fixators

Linear-circular hybrid fixators were used to stabilize humeral and femoral fractures in 21 dogs and five cats. Twenty-two of 24 fractures with sufficient follow-up radiographic evaluation obtained union. Time to radiographic union ranged from 25 to 280 days (mean +/- standard deviation [SD] 110+/-69 days; median 98 days). Eleven animals developed minor and two dogs developed major pin and/or wire tract inflammation. Functional outcome was rated as excellent (n=16), good (n=5), and fair (n=3) at the time of final long-term assessment (range 4.5 to 60.0 months; mean +/- SD 28.4+/-15.4 months; median 28.5 months). Follow-up information was unavailable for two animals. Hybrid fixators were useful constructs for stabilization of humeral and femoral fractures, particularly fractures with short, juxta-articular fracture segments.     

Management of femoral fractures in dogs with unilateral semicircular external skeletal fixators

Objective: To report use of semicircular external skeletal fixators (ESF) for management of femoral fractures in dogs. Study Design: Prospective clinical study. Animals: Dogs (n=16) with femoral fractures (n=18). Methods: A semicircular ESF system composed of 6‐hole 45° or 5‐hole 40° carbon‐fiber arches, 6 mm threaded rods, half pin fixation bolts, 6 mm nuts, and negative profile end‐threaded half pins were used for open repair of femoral fractures. ESF configuration, complications, limb use, fixator removal time, and functional outcomes were evaluated. Outcome was graded as excellent, good, fair, or poor. Results: Seventeen fractures with sufficient follow‐up healed. Eight dogs started using the limb immediately after waking up from anesthesia whereas initial limb use was 1–4 days after repair in the other dogs. Time to fixator removal ranged from 28 to 63 days (mean, 38 days). Functional outcome was excellent in 13 cases, good in 4, and poor in 1 nonunion. Conclusion: Semicircular ESF combined with open surgical reduction can be used to successfully repair metaphyseal and diaphyseal femoral fractures in young growing dogs.     

Prognostic factors in treating antebrachial growth deformities with a lengthening procedure using a circular external skeletal fixation system in dogs

OBJECTIVE: To evaluate treatment of antebrachial growth deformities (AGD) with a lengthening procedure using a circular external skeletal fixation (CESF) system and to determine prognostic factors. STUDY DESIGN: Prospective clinical study. ANIMALS: Thirty-four dogs with unilateral AGD. METHODS: Length deficits, angular and rotational deformities, elbow incongruity (EI), osteoarthritis (OA) of the elbow and carpal joint, function, and cosmesis were determined before and after a CESF lengthening procedure. RESULTS: On admission, EI (21 dogs; 62%), OA of the elbow joint (17 dogs; 50%), carpal OA (12 dogs; 35%), and concomitant elbow and carpal OA (5 dogs; 7%) were common findings. Treatment significantly improved function (normal, 20 dogs; 60%) and cosmesis (normal, 22 dogs; 65%). Angular and rotational deformities were almost completely corrected with small remaining length deficits. Elbow and carpal OA increased significantly during the follow-up period. Significant correlations were demonstrated between initial elbow OA and final function (R=0.42, P=.02), initial function and final function (R=0.41, P=.02), and initial ulnar and radial deficit and final cosmesis (R=0.58, P=.0001 and R=0.45, P=.008). CONCLUSIONS: Treatment of AGD by a CESF lengthening procedure was successful despite small remaining length deficits. Initial elbow OA, function, and ulnar and radial length deficits are prognostic factors in the treatment of AGD. CLINICAL RELEVANCE: Initial elbow OA and initial function are prognostic factors in predicting the functional outcome of treatment of AGD with a CESF lengthening procedure in the dog.     

Treatment of radius-ulna and tibia fractures with circular external skeletal fixator in 19 dogs

This study was carried out on 19 dogs of different breed, age and sex. 10 different types of radius-ulna and 9 tibia fractures were treated by circular external skeletal fixator. The cases were followed by clinical and radiological controls in the postoperative period. It was observed that the cases tolerated the apparatus well. There was no looseness of fixator stability and configuration during the 15-day interval examination. Complications like pin track, serous drainage and pin loosening were observed postoperatively. It was concluded that radiographic, clinical and anatomical data together with good preoperative planning, the Ilizarov Method and circular external skeletal fixator was successful for the treatment of open or closed fragmented radius-ulna and tibia fractures in dogs.     

Effect of various distal ring-block configurations on the biomechanical properties of circular external skeletal fixators for use in dogs and cats

OBJECTIVE: To evaluate mediolateral, axial, torsional, and craniocaudal bending behavior of 6 distal ring-block configurations commonly used to stabilize short juxta-articular bone segments in small animals. SAMPLE POPULATION: 8 circular external skeletal fixator constructs of each of 6 distal ring-block configurations. The distal ring-block configurations were composed of combinations of complete rings, incomplete rings, and drop wires. PROCEDURE: Constructs were nondestructively loaded in axial compression, craniocaudal bending, mediolateral bending, and torsional loading by use of a materials testing machine. Gap stiffness was determined by use of the resultant load displacement curve. RESULTS: Circular external skeletal fixator configurations and constructs significantly affected gap stiffness in all testing modes. Within each loading mode, gap stiffness was significantly different among most configurations. In general, complete ring configurations were significantly stiffer than similar incomplete ring configurations, and addition of a drop wire to a configuration significantly increased stiffness of that configuration. CONCLUSIONS AND CLINICAL RELEVANCE: When regional anatomic structures permit, the use of complete ring configurations is preferred over incomplete ring configurations. When incomplete ring configurations are used, the addition of a drop wire is recommended.     

Arthrodesis tarsocrural or tarsometatarsal in 2 dogs using circular external skeletal fixator

An external fixation technique, using a circular fixator, to obtain arthrodesis was evaluated in 2 dogs with infected open lesions and soft tissue damage. In both cases, articular cartilage was curetted, and devitalized bone and necrotic soft tissue were removed. No bone graft was used. The wounds were maintained open and the dogs received postoperative antibiotic therapy. The arthrodesis site was compressed progressively as needed. Infection was eradicated and bony union was obtained in both dogs. It was concluded that the use of a circular fixator is an effective method to achieve arthrodesis.     

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.     

Evolution of the treatment of canine radial and tibial fractures with external fixators

OBJECTIVES: To determine if indications for external fixator treatment of radial and tibial fractures, management of the fractures, or outcomes have changed over three decades. METHODS: Three groups of dogs were identified from discrete time spans within three decades and the medical records and radiographs were evaluated. The groups were compared in order to determine whether indications (signalment, etiology, fracture type and configuration), reduction method, equipment and implants, frame types and pin numbers, numbers of radiographic reevaluations, use of destabilization, frequency of pin track osteolysis, frame removal times and percentage of complications remained the same over the decades. RESULTS: The indications for external fixator treatment of radial and tibial fractures remained consistent over three decades. The equipment and implants changed over the decades. Frame construction changed from the predominately Type II frames constructed in the 1980's and 1990's to a variety of modified Type II, Type Ia, Type Ib and hybrid frames constructed in the 2000's. The frequency of pin track osteolysis decreased significantly over the decades. Frame removal times have not changed significantly over the past three decades. Complications (nonunion, delayed union, osteomyelitis, implant failure and premature frame loss) have decreased over this time. CLINICAL SIGNIFICANCE: Improvements in techniques and equipment have led to decreased complications with external fixators.     

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.     

A clinical evaluation of pancarpal arthrodesis in nine dogs using circular external skeletal fixation

OBJECTIVE: To report clinical outcome and complications after pancarpal arthrodesis using circular external skeletal fixation (CESF) in dogs. STUDY DESIGN: Retrospective study. ANIMALS: Dogs (n=9) with carpal injury. METHODS: Medical records including radiographs (10 limbs) with underlying severe carpal injury that had pancarpal arthrodesis with CESF were reviewed. Short-term follow-up (>6 months) was obtained by phone interview of owners. RESULTS: Mean weight was 24.5 kg (range, 10.1-69.5 kg). Mean duration until CESF removal was 110.6 days (range, 72-149 days). Complications in all dogs were mild postoperative edema of the distal aspect of the limb and initial mild serous discharge form exit points of CSEF wires. Follow-up (mean, 328 days; range, 190-541 days) was available for 8 dogs. All owners reported limb function and cosmesis as being excellent, and perceived that their animals were pain free. Perception of fixator care difficulty, as reported by owners, varied significantly based on previous splint management experience; owners who had experienced splint management for >1 month found fixator care equal to or easier than splint management. CONCLUSION: Pancarpal arthrodesis with a CESF produces a favorable clinical outcome with high owner acceptance. CLINICAL RELEVANCE: Pancarpal arthrodesis by use of CESF is a clinically applicable technique and may offer advantages over internal fixation with respect to postoperative complications.     

Use of hinged circular fixator constructs for the correction of crural deformities in three dogs

Background Hinged circular external skeletal fixator constructs are used to perform sequential correction of angular limb deformities, often with resultant limb segment lengthening, via distraction osteogenesis. Although there are several reports describing the use of these constructs for correction of antebrachial deformities in dogs, there is little information regarding their use on other limb segments. This report describes the use of hinged circular fixator constructs for the correction of acquired crural deformities in three skeletally immature dogs. Case reports Two dogs had purely frontal plane deformities (one valgus, one varus) and the third dog had frontal (valgus) and sagittal (recurvatum) components to its deformity. At the time of long‐term evaluation, frontal plane angulation relative to the contralateral limb improved from 40° to 22° of valgus, 30° to 5° of valgus, and 20° to 1° of varus in the three individual dogs. Tibial length discrepancies of 12% and 22% that were initially present in two dogs were improved to 6% and 10%, respectively, of the contralateral tibial length at the time of final evaluation; both dogs had compensatory growth of the ipsilateral femur and all dogs had an excellent functional outcome. Conclusion These cases illustrate the value of using hinged circular fixator constructs for correction of crural angular deformities, particularly when length discrepancies of the tibia are present.     

Unifocal internal and external bone lengthening with circular external skeletal fixator in 5 dogs

The purpose of this study was to investigate the effectiveness of treatment of long bone defects and extremity shortness in 5 dogs using circular external skeletal fixator. In one case a bone necrosis and osteomyelitis shortened radius by 7.0 cm; however in others extremity shortening between 3.0 and 6.0 cm affected radius-ulna or tibia. 2 or 3 rings of 80.0-100.0 mm diameters, and 3 rods were used as a circular external skeletal fixator. The distractions at the rate of 0.5 mm X 2 times/day were performed following a latent period of 3 days after the corticotomy. Unifocal internal lengthening for case 1 and unifocal external lengthening for the others were performed. Distraction was performed between 30 and 70 days (mean 50 days). It was noted that the circular external skeletal fixator was well-tolerated in all cases. The first usages of limbs in all cases were on postoperative day between 8 and 43 (mean 22 days). The radiographic follow-up examinations revealed a complete consolidation on postoperative day between 35 and 75 (mean 55.6 days). The fixators were removed on the postoperative day between 45 and 85 (mean 65 days). The treatment was successful in restoring the appropriate length of the limbs. After removing the fixator, functional and cosmetic results were graded as excellent in 3 cases, good in one case and fair in one case.     

Application and postoperative management of external skeletal fixators.

Application of external skeletal fixation involves preoperative assessment of the fracture with regards to healing potential of the bone and stabilizing requirements of the fixator. The fixator can be used alone or with supplemental (IM pin, cerclage, hemicerclage, Kirschner wires, bone screws) fixation to counteract shear, bending, and torsional forces at the fracture site. In addition, cancellous bone grafting can be used to enhance fracture healing. Rigid frames should be based on predrilling pilot holes followed by slow speed or hand insertion of smooth and threaded pins. Precise knowledge of regional anatomy precludes iatrogenic neurovascular or muscular tissue damage, which, subsequently, improves patient morbidity. Postoperative care of the fixator consists of bulky wraps to control pin-skin motion and cleaning of pin tract drainage sites. "Dynamization" or bone loading can be performed during fracture healing to stimulate osteosynthesis. This involves staged disassembly and reduction of frames by removing pins and connecting rods.     

Management of fractures near the carpal joint of two calves by transarticular fixation with a circular external fixator

A four-ring circular external skeletal fixation device was evaluated for transcarpal fixation of compound fractures in two calves. Case 1 was an eight-month-old female Holstein-Friesian x indigenous breed calf weighing 72 kg, which had a Salter-Harris type II fracture at the distal metaphysis of the right radius/ulna with an open contaminated wound on the medial aspect of the carpus. Case 2 was an 18-month-old crossbred Haryana heifer weighing 105 kg, which had a comminuted fracture at the proximal end of its left metacarpus with severe soft tissue trauma and an open wound on the medial aspect. In both cases, the fractures were repaired with four-ring circular fixators by fixing the proximal two rings in the distal radius/ulna and the distal two rings in the metacarpus. Postoperatively, both calves were treated with analgesic and anti-inflammatory drugs and antibiotic, and the pin-bone interfaces and the open wound were cleaned regularly with povidone-iodine solution. In both animals weight bearing was good to excellent in the immediate postoperative period. The fixator was well maintained and tolerated by the animals until the fractures healed after 45 to 60 days. The movement of the carpal joint was slightly affected when the fixator was removed on day 60, but a follow-up examination after one year showed that both calves had normal functional usage of the limbs.