Bilateral wedge ostectomy on an 18-month-old llama with severe bilateral carpal valgus.

An 18-month-old llama was admitted with severe (45 degrees and 40 degrees) bilateral carpal valgus. The llama had grown normally until it was 6 months old, when the carpal deviations had commenced. Radiography revealed abnormalities at the distal ulnar physes. Premature closure of these physes or abnormal distal ulnar growth may have been the cause of the carpal valgus. The owners requested surgical correction of the condition. Medial wedge osteotomies of each radius were performed 3 weeks apart. Internal fixation of the osteotomized radial bones was accomplished with small right-angled T plates, and the limbs were placed in full-limb casts for 3 weeks and tube casts for 3 more weeks. Both limbs healed in straight alignment, and the llama was able to walk and run normally. Dorsal subluxation of the right radiocarpal joint was noticed after the operation. This was believed to be caused by the uncorrected dorsal bowing of the distal portion of the radius, which had occurred secondary to the severe carpal valgus.     

CORRECTION OF ANGULAR DEFORMITY BY ASYMMETRIC PHYSEAL GROWTH AND BONE REMODELLING

Angular deformities of 25 or 37 degrees valgus were created by transverse wedge osteotomies in the diaphysis of the radius in 3-month-old Cocker Spaniels. Spontaneous correction was judged from radiographs until skeletal maturity. The magnitude of correction was estimated, using the opposite normal leg as a control. Asymmetrical physeal growth corrected the induced angulation between the proximal and distal radial joint plane surfaces (joint plane angle). The average correction of the joint plane angle was 80% in the 25 degree group, and 72% in the 37 degree group. Bone remodeling of the radial shaft corrected the induced diaphyseal angulation by 50% in both groups during the study.     

Principles of uniapical and biapical radial deformity correction using dome osteotomies and the center of rotation of angulation methodology in dogs

OBJECTIVE: To describe the normal anatomic axis of the canine radius in 2 planes (frontal, sagittal), and report the use and efficacy of dome osteotomies for acute correction of canine antebrachial deformities. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Normal antebrachii (n = 20) radiographs were used as a reference, and 7 dogs with 9 radial angular limb deformities that were corrected by use of dome osteotomies. METHODS: Orthogonal radiographs of 20 normal antebrachii were used to determine normal ranges of frontal (FPA) and sagittal plane anatomic axes (SPA). Pre and postoperative radiographs of 7 dogs (9 radii) that had surgical correction of radial angular limb deformities by dome osteotomies were reviewed. Success at deformity correction into established normal ranges and to the normal contralateral side, if present, was determined. RESULTS: Normal ranges were FPA, 0-8 degrees and SPA, 8-35 degrees . There were 4 biapical and 5 uniapical deformities. FPA and SPA were corrected into normal range in 66% and 78% of affected limbs, respectively; however, only 44% of radii were corrected into normal ranges in both planes. CONCLUSIONS: Ranges for normal canine radial axes can be used as goals for angular limb correction when there is bilateral angular deformity. The dome osteotomy technique is advantageous in certain conditions for biplanar deformity correction. CLINICAL RELEVANCE: Dome osteotomies can be used to correct radial deformities in the frontal and sagittal planes, with certain advantages, but are heavily reliant on appropriate preoperative planning.     

Trauma-induced growth abnormalities of the distal radius in three cats

Three immature cats with growth abnormalities of the distal radius secondary to trauma were presented between July 2001 and July 2003. Initial injuries included a Salter-Harris type II fracture of the distal radial physis in one cat, fractures of the styloid process of the ulna in two cats, and metacarpal fractures in one cat. The cats were between 3.5 and 4.5 months of age at the time of injury. Damage to the distal radial physis resulted in a variable degree of shortening of the radius in all cats. Asymmetrical closure caused widening of the lateral aspect of the radiocarpal joint space in two cats. Elbow incongruity was not observed. One cat was treated with osteotomies of the radius and ulna and realignment of the radius, stabilised with external skeletal fixation. Another was treated by ulnar ostectomy alone. Radius and ulna osteotomies and distraction osteogenesis of the radius were performed in the third cat. Clinical outcome was satisfactory in all three cases.     

Long-term outcome of distal femoral osteotomy for treatment of combined distal femoral varus and medial patellar luxation: 12 cases (1999-2004)

OBJECTIVE: To determine long-term outcome of distal femoral osteotomy as a component of treatment for distal femoral varus and medial patellar luxation in large-breed dogs. DESIGN:Retrospective case series. ANIMALS: 12 dogs (16 stifle joints). PROCEDURES: Medical records and radiographs were reviewed to identify large-breed dogs with medial patellar luxation (grade > or = 2) and femoral varus angle > or = 12 degrees treated with distal femoral osteotomy, with a minimum follow-up (by a veterinarian) of 18 months. Signalment, weight, medial patellar luxation and lameness grade, pre- and postoperative femoral varus angle, surgical technique, time to radiographic bone union, and complications were recorded. Follow-up with owners via questionnaire was performed > 18 months after surgery. RESULTS: 16 corrective distal femoral osteotomies were performed with ancillary medial patellar luxation procedures in 12 dogs; 4 dogs had staged bilateral procedures. Mean +/- SD preoperative and postoperative femoral varus angles were 16.3 +/- 4.3 degrees and 3.9 +/- 2.5 degrees , respectively. Mean +/- SD time to radiographic union of the distal femoral osteotomy was 52.6 +/- 13 days. One dog had Kirschner wire migration from the tibial tuberosity. Patellar luxation was not detected after surgery in any dog. Mean +/- SD follow-up by a veterinarian was 1,335 +/- 410 days and by use of an owner questionnaire was 1,497 +/- 464 days. All 10 variables of owner-observed patient comfort and function were significantly improved. CONCLUSIONS AND CLINICAL RELEVANCE: Distal femoral osteotomy in combination with traditional treatment provided predictable osteotomy healing, patellar stabilization, and long-term improvement in patient comfort and function when used to treat combined distal femoral varus and medial patellar luxation in large-breed dogs.     

In vitro effects of osteotomy angle and osteotomy reduction on tibial angulation and rotation during the tibial plateau-leveling osteotomy procedure

OBJECTIVE: To determine the effect of osteotomy angle, reduction technique, and tibial plateau rotation angle on angular and rotational limb deformities. STUDY DESIGN: Geometric comparison using bone models. METHODS: Rotational osteotomies were made in the proximal metaphysis of artificial tibias at 0 degrees, 10 degrees, 20 degrees, -10 degrees, and -20 degrees from perpendicular with respect to either the proximodistal and craniocaudal tibial axes. Negative-numbered angles represented osteotomies made from distal to proximal or caudal to cranial. Changes in tibial angulation and torsion were measured using a 3-dimensional digitizing instrument at tibial plateau rotation angles from 0 degrees to 30 degrees at 5 degrees increments. Two osteotomy reduction techniques were used: complete osteotomy reduction and alignment of the medial cortex. The mean of 5 measurements of torsional and angular tibial deformity for each of the 9 osteotomy orientations in each reduction technique group was obtained. RESULTS: All had increasing angular and rotational deformity as tibial plateau rotation angle increased. In the medially aligned cortex group, all tibias had valgus deformity, and 8 of 9 tibias were internally rotated. In the reduced osteotomy group, minimal angular deformity was seen in tibias with osteotomy variation along the proximodistal axis; however, tibias with osteotomy variation along the craniocaudal axis had angular deformity ranging from 6.0 degrees of varus deformity to 14.3 degrees of valgus deformity. Rotational deformity was affected similarly by osteotomy variation along either axis. Reduction technique had greater affect on angular and rotational deformity than osteotomy angle variation. CLINICAL RELEVANCE: These results suggest that osteotomy reduction may play a greater role in angular and rotational deformity than osteotomy angle, although extreme osteotomy angles should be avoided. To decrease the severity of deformity, we recommend that the osteotomy be made perpendicular to the craniocaudal and proximodistal axes and be completely reduced with less regard for alignment of the medial cortex.     

Asynchronous Growth of the Canine Radius and Ulna: Surgical Correction following Experimental Premature Closure of the Distal Radial Physis

Marked lameness and elbow incongruity occurred in seven 21-week-old dogs following experimental premature closure of the distal radial physis at 10 weeks of age. Midradial transverse osteotomies and bone plate stabilization performed on five dogs resulted in marked reduction of elbow incongruity and forelimb lameness. Two dogs had no surgery and served as controls for the surgical procedure. At 50 weeks of age the proximal radial articular surface was displaced 5.3 mm farther from the coronoid process in control dogs as compared to dogs having transverse radial osteotomy. Markedly worse clinical, radiographic, and pathologic changes in the control group demonstrated the importance of reestablishing and preserving elbow congruity when treating asynchronous growth of the canine forelimb caused by premature closure of the distal radial physis. The technique described is recommended as one method to treat premature distal radial physeal closure clinically.     

In vitro evaluation of a custom cutting jig and custom plate for canine tibial plateau leveling

OBJECTIVE: To design and manufacture custom titanium bone plates and a custom cutting and drill guide by use of free-form fabrication methods and to compare variables and mechanical properties of 2 canine tibial plateau leveling methods with each other and with historical control values. SAMPLE POPULATION: 10 canine tibial replicas created by rapid prototyping methods. PROCEDURES: Application time, accuracy of correction of the tibial plateau slope (TPS), presence and magnitude of rotational and angular deformation, and replica axial stiffness for 2 chevron wedge osteotomy (CWO) methods were assessed. One involved use of freehand CWO (FHCWO) and screw hole drilling, whereas the other used jig-guided CWO (JGCWO) and screw hole drilling. RESULTS: Replicas used for FHCWO and JGCWO methods had similar stiffness. Although JGCWO and FHCWO did not weaken the replicas, mean axial stiffness of replicas after JGCWO was higher than after FHCWO. The JGCWO method was faster than the FHCWO method. Mean +/- SD TPS after osteotomy was lower for FHCWO (4.4 +/- 1.1 degrees ) than for JGCWO (9.5 +/- 0.4 degrees ), and JGCWO was more accurate (target TPS, 8.9 degrees ). Slight varus was evident after FHCWO but not after JGCWO. Mean postoperative rotation after JGCWO and FHCWO did not differ from the target value or between methods. CONCLUSIONS AND CLINICAL RELEVANCE: The JGCWO method was more accurate and more rapid and resulted in more stability than the FHCWO method. Use of custom drill guides could enhance the speed, accuracy, and stability of corrective osteotomies in dogs.     

Use of radiographic measures and three-dimensional computed tomographic imaging in surgical correction of an antebrachial deformity in a dog

CASE DESCRIPTION: A 1-year-old 7.4-kg (16.3-lb) castrated male mixed-breed dog was evaluated because of intermittent lameness and an antebrachial angular limb deformity. CLINICAL FINDINGS: The left forelimb had gross antebrachial external rotation (approx 90 degrees ) and marked procurvatum. Radiography revealed a severe partially compensated biapical antebrachial angular limb deformity. Measurements of medial proximal radial angle (MPRA) and lateral distal radial angle (LDRA) were obtained from orthogonal radiographs of the proximal and distal segments of the radius, respectively. Elbow joint-to-carpus translation was quantified. Deformities were localized and quantified by the center of rotation of angulation (CORA) method. Computed tomographic 3-dimensional image reconstructions of the antebrachium and carpus were completed to create 3 life-size stereolithographic models. TREATMENT AND OUTCOME: 2 closing wedge radial osteotomies were performed at the level of the CORAs and stabilized with bone plates and screws. RESULTS: Frontal and sagittal plane alignments were corrected to 8 degrees and 15 degrees , respectively (reference limits, 0 degrees to 8 degrees and 8 degrees to 35 degrees , respectively). The MPRA was corrected from 55 degrees to 68 degrees , and LDRA was corrected from 32 degrees to 76 degrees (values considered normal are approx 85 degrees and 87 degrees , respectively). Elbow joint-to-carpus translation was improved by 42.5%. After 8 weeks, radiography revealed bone union. Owners considered the outcome acceptable, on the basis of limb appearance and lack of lameness at 1 year after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: A segmental radiographic planning technique combined with the CORA method, computed tomography, and stereolithography may be useful in the characterization of and planning corrective surgery for forelimb deformities in dogs.     

Effect of humeral osteotomy on joint surface contact in canine elbow joints

OBJECTIVE: To determine the effect of sliding and wedge osteotomies of the humerus on the joint surface contact areas in anatomically normal elbow joints of dogs. SAMPLE POPULATION: Left thoracic limbs from 5 skeletally mature mixed-breed canine cadavers. PROCEDURE: Joint casting was performed by placement of colored polymethylmethacrylate in the elbow joint cavity followed by loading in a materials testing system at physiologic angle and load. Joint casting was performed in unaltered specimens, after 10 degrees medial opening wedge osteotomy, and after lateral sliding osteotomy of the proximal portion of the humerus. Computer-aided analysis of photographs of proximal radial and ulnar articular surfaces after each casting procedure was performed. RESULTS: The lateral sliding humeral osteotomy and 10 degrees medial opening wedge osteotomy significantly altered joint surface contact regions of the canine elbow joint. Osteotomies resulted in a reduction in the size of the radial, ulnar, and combined radioulnar contact areas. Both osteotomies also resulted in craniolateral migration of the radial contact area and craniomedial recession of the ulnar contact area. Although the reduction in ulnar contact area with these treatments is consistent with our hypotheses, the reduction in radial contact area was not anticipated. CONCLUSIONS AND CLINICAL RELEVANCE: Humeral osteotomies alter joint surface contact areas of the canine elbow joint in vitro. Humeral osteotomies may decrease contact areas on the diseased region of the joint in dogs with elbow dysplasia; however, the overall decrease in joint surface contact area suggests that these procedures may induce focal increases in pressure that may cause iatrogenic cartilage damage when applied in vivo.     

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.     

Correction of angular deformities caused by premature closure of the distal ulnar epiphyseal plate in dogs

Surgical correction of angular deformities caused by premature closure of the distal ulnar growth plate in dogs. Correction of angular deformities in 14 cases of premature closure of the distal ulnar growth plate is described. Angular deformities were most frequently seen in large breeds during the most active phase of growth at 3-5 months of age. Preoperative axial deviations measured on radius were from 7 to 38 degrees in valgus and 0 to 35 degrees in antecurvation compared with the contralateral leg. According to the kind of treatment, the dogs were divided into two groups: In group I which consisted of cases with sufficient remaining growth potential of the radius, segmental ostectomy of ulna with insertion of an autologous fat graft in the ostectomy diastasis was performed to allow spontaneous correction by asymmetrical epiphyseal growth. In group II reconstructive osteotomy and stable, internal fixation with a plate was accomplished. The cosmetic result was judged as excellent in 10 cases, good in 3 and less favourable in 1. Postoperative follow up time was in average 33 months. On control 43% of the dogs showed no lameness, 57% were slightly lame after exercise or rest. None of the cases turned out to be permanently lame at the end of the follow up investigation.     

Lower Extremity Amputation and Application of a Prosthetic Device in a 1-Month-Old Calf

During correction of a dystocia, a fracture occurred involving the right third and fourth metacarpus of a calf. Application of a plaster cast resulted in devitalization of the limb. The distal limb was amputated, and a prosthetic device capable of periodic lengthening was fitted. The calf was able to walk well 1 month following surgery.     

Tibial plateau leveling osteotomy and cranial closing wedge ostectomy in a cat with cranial cruciate ligament rupture

A 5-year-old domestic shorthair cat was presented for a nonweight-bearing left pelvic-limb lameness. Orthopedic and radiographic examinations revealed a cranial cruciate ligament rupture and deformity of the proximal tibial metaphysis. The deformity of the proximal tibia resulted in an exaggerated tibial plateau angle of approximately 75 degrees. Surgical correction was performed with a combination of tibial plateau leveling osteotomy and cranial closing wedge ostectomy. The procedures resulted in an excellent clinical outcome with immediate return to weight bearing in the operated limb and progressive improvement in function over the ensuing 4 months.     

Axial correction of pes varus by transverse-opening wedge osteotomy and T-plate fixation with beta-tricalcium phosphate (beta-TCP) transplantation in dachshunds

Axial correction was performed surgically in two miniature dachshunds presenting with lateral patellar dislocation and limping caused by pes varus. Pes varus had resulted from asymmetric closure of the physis of the distal tibia. Prior to surgery, osteotomy was simulated by measuring X-ray films to determine the distance required for the wedge opening. Transverse-opening wedge osteotomy was performed on the medial side of the distal tibia, and beta-tricalcium phosphate (beta-TCP) was inserted in a wedge shape into the area created by the cuneiform osteotomy. Finally, the tibia was fixed by a veterinary 1.5/2.0-mm T-plate. Both dogs were able to walk a few days after surgery, and the lateral dislocation of the patella normalized almost completely in about one month. At two months, X-ray films showed that the implant had remained in position without any dislocation, and the beta-TCP had fused with the surrounding bone.     

Use of a double-hook plate to repair a subtrochanteric femoral fracture in an immature dog

A subtrochanteric femoral fracture in a 5-month-old Doberman Pinscher was repaired by use of a 5-hole, 3.5-mm, double-hook plate. The double-hook plate afforded rigid 3-point fixation of the short proximal metaphyseal segment without impingement of the proximal femoral physis and allowed compression of the fracture fragments by placement of an interfragmentary screw through its pendulum hole. The fracture healed without complications, and the dog had a rapid return to function. Although designed for use in performing femoral osteotomies in dogs afflicted with hip dysplasia, the double-hook plate can be used to repair fractures with short proximal or distal segments.     

An In Vitro Biomechanical Comparison of Dynamic Condylar Screw Plate Combined with a Dorsal Plate and Double Plate Fixation of Distal Diaphyseal Radial Osteotomies in Adult Horses

Objective— To compare stiffness and strength of a dynamic condylar screw plate combined with dorsal broad dynamic compression plate (DCS–bDCP) fixation with double broad dynamic compression plate (dbDCP) fixation used to repair oblique distal fractures of adult equine radii. Study Design— Experimental. Sample Population— Adult equine radii (n=10 pair). Methods— An unconstrained three‐dimensional loading–measurement system was used to determine stiffness of a 50 mm long intact, and then DCS–bDCP or dbDCP‐plated osteotomized/ostectomized segment of radii when subjected to a nondestructive sequence of compression, torsion, and lateral‐to‐medial (LM), medial‐to‐lateral (ML), cranial‐to‐caudal (CrCa), and caudal‐to‐cranial (CaCr) bending. Uniform load over the entire length of construct identified its weakest characteristics during torsion and LM and CrCa bending to failure. Results— No difference was observed between osteotomized/ostectomized DCS–bDCP and dbDCP construct stiffness for all 6 loading modes, and strength for all 3 failure loads. Ostectomized DCS–bDCP and dbDCP construct stiffness was significantly lower than osteotomized radii, the latter approaching intact for axial, LM, and CrCa bending. Most frequent failure was bone fracture through exit site of a screw located adjacent to osteotomy/ostectomy. Conclusions— DCS–DCP and dbDCP constructs had comparable strength and stiffness when repairing osteotomies/ostectomies in equine adult radius bone. Fracture reduction increased stiffness that approached intact bone for loads that placed the unplated side in compression. Clinical Relevance— DCS–bDCP and dbDCP constructs are comparable in stiffness and strength when applied to oblique distal diaphyseal osteotomies/ostectomies in equine radius bone. However, the DCS's localized effect on distal epiphyseal structure because of additional bone removal remains to be investigated under in vivo articular loading conditions.     

Chronic ileocecal intussusception in horses

Ten young horses with signs of simple partial obstruction of the small intestine were found upon surgical exploration of the abdomen to have chronic intussusception of the distal ileum into the cecum. Poor general physical condition, intermittent or continual abdominal pain of varying degree, depression, and poor appetite were consistent clinical findings. Rectal palpation in eight animals was suggestive of an incomplete or intermittent obstruction of the small intestine. Laboratory determinations were not helpful in making a diagnosis. Dilatation and hypertrophy of the distal jejunum and ileum were associated surgical findings indicating chronicity of the problem. Surgical correction utilizing an end-to-side or a side-to-side anastomosis of small intestine to cecum resulted in recovery in 7 of 8 cases which could be followed long term. Failure to resect the abnormal segment of small intestine did not affect the outcome.     

Observations on the repair of distal radial osteotomies in the dog by double hook plates

Distal radial osteotomies in the dog repaired with a double hook plate achieved early return to full function. All dogs in this study reached and maintained the desired clinical evaluation score of grade four by the third postoperative week. The average loss of total range of carpal joint motion was 36 degrees. The double hook plate provides stable fixation and can be applied with three point fixation to a bone segment as short as 12 mm.     

Effect of heel elevation on forelimb conformation in horses

OBJECTIVE: To determine the conformational changes in the distal forelimb of horses following heel elevation of 15 degrees and greater. An experimental study with repeated, within-horse measurements. PROCEDURE: Five clinically normal, mixed-breed horses were used to determine distal forelimb conformation following heel elevation from 0 to 45 degrees in 15 degree increments. Data were also compared to conformation of the limb in a Kimzey splint. Conformation was determined using lateral to medial radiographic projections. Conformation parameters assessed included measurement of apparent lengths of digital flexor tendons from the origin of their accessory ligaments to the points of insertion, and the joint angles of the distal limb. RESULTS: For angles of heel elevation from 15 to 45 degrees, the degree of joint angulation increased (increasing flexion) with heel elevation for the metacarpophalangeal, and proximal and distal interphalangeal joints. Conversely, the measured apparent lengths of the digital flexor tendons in the distal limb, decreased. CONCLUSION: The data supports the practice of elevating the heel (greater than 15 degrees) for conditions in which decreased fetlock extension may be desired such as with laceration or injury to the digital flexor tendons. Further study is required to determine whether heel elevation greater than 15 degrees reduces in vivo digital flexor tendon tension and also to ensure that the marked flexion of the distal interphalangeal joint with greater heel elevation is not detrimental over a prolonged period that may be required for the rehabilitation of flexor tendon injuries in the horse.