Surgical Management of Lateral Luxation and Subluxation of the Canine Radial Head

The causes and pathogenesis of radial head luxation and subluxation are reviewed. A surgical technique is described for repair of the condition that permits direct visualization of the joint, reestablishment of normal joint anatomy by ulnar osteotomy, and stabilization of the radioulnar articulation with a lag screw. Two clinical cases are presented.     

Limb-sparing surgery in a dog with osteosarcoma of the proximal femur

OBJECTIVE: To report successful limb-sparing surgery in a dog with a proximal femoral osteosarcoma (OSA) using a composite allograft-prosthetic technique. STUDY DESIGN: Case report. ANIMAL: Client-owned dog. METHODS: A stage IIB OSA of the proximal aspect of the femur was resected in accordance with oncologic and limb-sparing principles. The osseous defect was reconstructed with a proximal femoral allograft and cemented, long-stemmed femoral prosthesis. Soft tissue reconstruction was achieved by suturing host tendons to their respective allogeneic tendons on the allograft. Coxofemoral joint function was preserved using standard total hip arthroplasty techniques. RESULTS: Limb-sparing surgery of the proximal aspect of the femur using a composite allograft-prosthetic technique resulted in excellent limb function. Postoperative complications included aseptic loosening of the femoral composite graft and allograft nonunion, which required revision, traumatic implant luxation, and local tumor recurrence. Limb function was excellent after surgical stabilization of the allograft nonunion but deteriorated after implant luxation 270 days postlimb-sparing surgery. Pulmonary and skeletal metastases were diagnosed and local tumor recurrence suspected 596 and 650 days postoperatively, respectively. The dog was euthanatized 688 days after limb-sparing surgery as a result of progressive local and metastatic disease. CONCLUSIONS AND CLINICAL RELEVANCE: Limb-sparing surgery for dogs with primary bone tumors of the proximal aspect of the femur is feasible with good functional results.     

Transverse ulnar bone transport osteogenesis: a new technique for limb salvage for the treatment of distal radial osteosarcoma in dogs

Objective— To develop instrumentation and a technique for transverse ulnar bone transport osteogenesis in dogs.
Study Design— Cadaveric study and in vivo validation (1 dog).
Sample Population— Paired cadaveric antebrachii (n=10 dogs) and 1 live dog.
Methods— Circular fixator constructs were applied and fitted with reeling or linear motors designed to transport an ulnar segment transversely into a defect created by excising the distal 50% of the ipsilateral radius. A longitudinal osteotomy of the adjacent ulna was created and the segment was transported across the radial defect. Pre- and post-distraction CT scans were used to compare the efficacy of each construct. The procedure was performed unilaterally in a live dog using the reeling motor (RM) construct.
Results— Both constructs effectively transported the ulnar segment into the defect. Subjectively, the RMs were easier to apply and operate. No significant differences were observed in the objective measures of efficacy between the 2 construct types. The live dog produced viable regenerate bone after transverse ulnar bone transport.
Conclusions— Transverse ulnar bone transport should be considered a potential method for limb salvage in dogs with osteosarcoma (OSA) of the distal radius. The RMs were effective and clinically applicable.
Clinical Relevance— Transverse ulnar bone transport osteogenesis affords the benefits of longitudinal radial bone transport osteogenesis, allowing resolution of large longitudinal radial defects in a substantially less time as a result of shortening the transport distance. This would be beneficial when treating conditions such as OSA where minimizing convalescence and maximizing quality of life is a priority.     

Total vertebrectomy for stabilisation of chronic spinal lumbar luxation in a paraplegic dog without nociception

An adult male crossbred dog was referred with a history of a road traffic accident that took place 1 month earlier. Neurological examination revealed paraplegia with absent nociception in the pelvic limbs. On epaxial palpation, significant curvature of the anatomical axis of the spine between the third and fourth lumbar vertebrae was observed, with the presence of a bone end almost piercing the dog's skin. Survey radiographs of the lumbar spine revealed severe dislocation between L3 and L4 vertebrae. During surgery, the spinal cord was not visible between the dislocated segments. Because of difficulties in reducing the lumbar luxation during surgery, vertebrectomy and vertebral shortening were performed. After alignment between vertebrae L3 and L5, eight cortical orthopaedic screws and bone cement were used for fixation. After 30 days, the dog started to use a wheelchair and was considered by its owner to have a good quality of life with no evidence of pain. To the authors’ knowledge, this is the first case of severe luxation treated by total vertebrectomy and spine shortening in a dog. This surgery can be considered as an option in the management of severe spine luxation when the spinal cord is physically transected.     

Patellar luxation as a complication of surgical intervention for the management of cranial cruciate ligament rupture in dogs. A retrospective study of 32 cases.

This retrospective study identified 32 cases of patellar luxation which occurred as a complication of surgical intervention for cranial cruciate ligament rupture (CCLR). The complication was recorded mostly in larger (>/=20 kg) dogs with the Labrador Retriever being the most common breed. The complication followed extra-capsular, intra-capsular and tibial plateau levelling surgery. The mean time from CCLR surgery to the diagnosis of patellar luxation was 14 weeks. The incidence of patellar luxation occurring as a complication of surgical intervention for CCLR was 0.18% of all CCLR corrective procedures. Corrective surgery for patellar luxation was successful in 79% of stifles. The patellar reluxation rate was significantly lower (p = 0.0007) when at least one corrective osteotomy (tibial tuberosity transposition, femoral trochlear sulcoplasty or tibial plateau levelling osteotomy with tibial axial re-alignment) was performed (35%), compared to when corrective osteotomy was not performed (100% patellar reluxation rate). When performing corrective surgery for patellar luxation following CCLR surgery, at least one corrective osteotomy should be performed in order to reduce the patellar reluxation rate. The correction of patellar luxation following surgery for CCLR is challenging and carries a significant rate of failure.     

Ipsilateral vascularised ulnar transposition autograft for limb-sparing surgery of the distal radius in 2 dogs with osteosarcoma

Canine osteosarcoma is the most commonly diagnosed primary bone tumour in the dog, affecting mainly large and giant breed dogs with the predilection site being the metaphysis of long bones, specifically the distal radius, proximal humerus, distal femur and proximal tibia and fibula. Treatment options are either palliative or curative intent therapy, the latter limb amputation or limb-sparing surgery together with chemotherapy. This article describes the use of an ipsilateral vascularised ulnar transposition autograft as well as chemotherapy in 2 dogs with osteosarcoma of the distal radius. Both dogs showed minimal complications with the technique and both survived over 381 days following the surgery. Complications seen were loosening of the screws and osteomyelitis. The procedure was well tolerated with excellent limb use. This technique is indicated for use in cases with small tumour size that have not broken through the bone cortex.     

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.     

Ankylosis of tarsometatarsal luxations using external fixation

This report evaluates the suitability of using an external fixator as the sole means of correcting tarsometatarsal luxations. Four dogs were included in this report. Each dog weighed more than 20 kg and had sustained a tarsometatarsal luxation with plantar, medial or lateral instability. The luxations were immobilised with an external fixator for between 12 and 17 weeks. The surgery did not involve soft tissue dissection, debridement of articular cartilage or a cancellous bone graft and no external coaptation was used postoperatively. The result of this treatment was to ankylose the tarsometatarsal luxation and allow the dogs to return to normal function.     

Congenital elbow luxation in the dog

Four cases of bilateral and two cases of unilateral congenital elbow luxation in the dog were reviewed. In all cases, lameness was severe, osseous abnormalities were marked, and the dislocations primarily involved the humeroulnar articulation. Treatment consisted of closed reduction and external support in one dog and surgical reduction and stabilization in four dogs. One dog died before surgery could be performed. Treatment resulted in return of function to the affected limbs, even though osseous abnormalities and varying degrees of malarticulation persisted. Posttreatment observations, for as long as 4 years, demonstrated the persistence of near normal function of the limbs and minimal elbow deformity.     

Use of a free cortical ulnar autograft following en bloc resection of a mandibular tumor

A dog was presented for the en bloc resection of a previously irradiated mandibular ossifying epulis. A central hemimandibulectomy was performed, and the mandibular defect was stabilized by the use of a free cortical ulnar autograft and rigid internal fixation. The dog had normal mastication and left forelimb function two weeks after surgery. Radiographic evaluation of the surgical site at three and 10 months after surgery showed normal bony healing.     

Treatment of methicillin-resistant Staphylococcus epidermidis infection following repair of an ulnar fracture and humeroradial joint luxation in a horse

A 27-month-old Rocky Mountain Horse was examined because of a fracture of the proximal portion of the ulna and luxation of the humeroradial joint (Monteggia fracture). Open reduction was performed, using a mechanical distractor, and the ulnar fracture was stabilized by application of a bone plate and screws. After surgery, the horse developed an infection of the surgical site, and bacterial culture of fluid from the surgical site yielded a pure growth of methicillin-resistant Staphylococcus epidermidis susceptible to oxytetracycline, erythromycin, rifampin, and vancomycin. Treatment with oxytetracycline did not result in a favorable clinical response. Therefore, the horse was treated systemically with vancomycin and rifampin, and vancomycin-impregnated polymethyl methacrylate beads were implanted at the surgical site. Six months after surgery, the horse was sound at a walk or trot, and bony union was evident on radiographs of the elbow joint.     

Use of the Ilizarov method of distraction osteogenesis for the treatment of radial hemimelia in a dog

A 6-month-old female crossbred dog with unilateral radial hemimelia was treated with a circular external fixator. During the first surgery, the dog underwent transverse osteotomy through the distal ulnar physis and rotation of the distal ulnar fragment (epiphysis) together with the forepaw in a lateral direction to achieve contact with the end of the proximal ulnar segment (shaft of the ulna); a circular external fixator was then applied. After removal of the fixator, a cast was applied. The initial intent was to preserve mobility of the ulnocarpal joint; however, the joint fused naturally. A second surgery was performed to lengthen the ulna by use of distraction osteogenesis. An Ilizarov external fixator was used, and the ulna was lengthened 25 mm. During the third surgery, osteotomy of the distal portion of the ulna was performed to treat residual deviation of the forepaw. The surgical treatment resulted in satisfactory use of the limb and a better quality of life.     

Surgical management of premature closure of the distal ulnar growth plate in a growing dog

Surgical management of deformity due to premature closure of the distal ulnar growth plate in a growing dog is discussed. The method of management selected was ulnar diaphyseal ostectomy with transphyseal wiring of the distal radius. Elbow subluxatin and degenerative joint disease as a consequence of premature ulnar closure are also discussed.     

An open reduction technique for chronic coxofemoral luxation in the dog

Extract

Coxofemoral luxation in the dog is an all too common condition encountered in rural practice in New Zealand. The treatments described for the reduction of this condition are many, which is a fair indication that none of them is particularly satisfactory. This may be owing, in part, to the fact that luxation of this joint is usually the result of an accident in which considerable force is exerted on the joint, which suffers severe trauma.     

Modified De Vita pinning technique for the management of canine hip luxation: preliminary findings

OBJECTIVE: To describe for the first time a modification of the De Vita pinning technique to manage hip luxation in the dog and to assess its use in a preliminary study. DESIGN: A prospective, clinical study using five client-owned dogs with naturally occurring injuries. PROCEDURE: A modified De Vita pinning technique was employed, using a nonthreaded Steinmann pin to reduce the risk of trauma to the sciatic nerve during pin insertion. The pin was anchored by implanted Kirschner-Ehmer clamps in an attempt to lower the risk of postoperative pin migration. RESULTS: Surgical outcome was very favourable with respect to pain on manipulation, restriction of range of movement and lameness in all dogs as assessed by veterinary examination. In four of five dogs, owners also reported normal movement at rest, walk and trot. The fifth dog was lost to follow-up. CONCLUSION: This preliminary study found that a modified De Vita pinning technique was useful in dogs with uni and bilateral hip luxation and hip luxation in the presence of other limb injuries. The modified technique may provide a sound surgical alternative to existing procedures. The described modification allows the use of a nonthreaded pin and also substantially reduces the risk of postoperative pin migration.     

A Retrospective Evaluation of Stifle Osteoarthritis in Dogs with Bilateral Medial Patellar Luxation and Unilateral Surgical Repair

The effects of surgical and nonsurgical therapy on the development of osteoarthritis were compared in 12 dogs with bilateral medial patellar luxation and unilateral surgical repair. Evaluations included severity of lameness and patellar luxation, ligamentous stability, range of motion, and radiographic evidence of osteoarthritis before surgery and at a mean of 33 months after surgery. Stifles without surgical treatment served as controls for the contralateral stifles with surgery. All stifles treated surgically had reduced patellofemoral joints, normal range of motion, and improved limb use. Osteoarthritis progressed significantly and comparably in both groups of stifles. Progression of osteoarthritis was not correlated with luxation grade, body weight, or interval from surgery to follow-up. Age at surgery was correlated positively with severity of osteoarthritis in the stifles treated surgically.     

SURGICAL MANAGEMENT OF A TRAUMATIC ELBOW LUXATION WITH CIRCUMFERENTIAL SUTURE PROSTHESES IN A RABBIT (ORYCTOLAGUS CUNICULUS)

A 2-year-old dwarf rabbit was referred for right forelimb lameness of 1-week duration. Physical examination and radiographic findings were consistent with an elbow luxation. Manual reduction under anesthesia was unsuccessful in correcting the luxated joint. A surgical approach was recommended to repair the rabbit elbow luxation. Transcondylar, transradial, and transulnar tunnels were drilled from lateral to medial with 2 suture prostheses being placed, 1 from the radius to the humerus and 1 from the humerus to the ulna. Analgesia was provided and the patient was reevaluated on days 2, 7, and 14 after the procedure. The luxation was reduced and no recurrence was noted a year following the surgical procedure. Circumferential suture prostheses, recently described with no reported postoperative complications in cats, can be used successfully in rabbits as evidenced in this case report.     

Ventral fixation of chronic atlanto-occipital luxation in a dog

A 4·5-year-old male Australian Kelpie was presented for evaluation of ambulatory tetraparesis and neck pain of five weeks duration. Atlanto-occipital luxation was diagnosed by computed tomography. The joint was unstable following closed reduction, and a ventral surgical approach to the cranial cervical spine and occiput permitted manual reduction and stabilisation of the atlanto-occipital joint. The thickened joint capsule and articular cartilage were removed to promote AO arthrodesis. Eight cortical screws, inserted into the occipital condyles and C1, were embedded in polymethylmethacrylate to stabilise the atlanto-occipital articulation. The dog recovered uneventfully after it was placed in a neck brace and rested for six weeks. Neurologic examination at six weeks was normal and the dog returned to normal farm work 12 weeks after surgery.     

T-plate fixation of distal radial closing wedge osteotomies for treatment of angular limb deformities in 18 dogs

OBJECTIVE: To describe the surgical technique and clinical results of treatment for forelimb angular limb deformities, secondary to premature distal radial or ulnar physeal closure, by using T-plate fixation of a distal radial closing wedge osteotomy in 18 dogs. STUDY DESIGN: Retrospective clinical study. SAMPLE POPULATION: 18 client-owned dogs. METHODS: The medical records of 18 dogs that underwent a distal radial closing wedge osteotomy with T-plate fixation for correction of a forelimb angular limb deformity were reviewed. Small pins (Kirschner wires) were used to obtain the appropriate alignment of the antebrachiocarpal and elbow joints and proper limb orientation. In-hospital follow-up evaluation was obtained at the time fracture healing was observed radiographically. Further long-term follow-up was obtained by owner interview. RESULTS: Osteotomy sites were radiographically healed within 4 to 12 weeks (mean, 8 weeks) after surgery in the 14 dogs that returned for in-hospital follow-up. Limb function was graded as good or excellent in all dogs. Long-term follow-up by owner interview rated limb function and cosmetic appearance as good to excellent in all dogs. Plate removal was necessary in one dog 7 months after surgery because of osteopenia in the radius. CONCLUSION: This surgical technique was considered successful in the treatment of angular limb deformities in all dogs. A good to excellent prognosis is to be expected with this technique, with minimal complications. CLINICAL RELEVANCE: The use of a T-plate for the correction of angular limb deformities has not been previously described in the literature. This technique permits accurate correction of the angular limb deformity and minimizes postoperative complications.     

Use of a Double Hook Plate for Treatment of a Distal Radial Fracture in a Dog

Attempted stabilization of open, distal radius and ulnar fractures in a 3-year-old German shepherd dog using intramedullary pins and a Schroeder-Thomas splint resulted in malalignment of the limb and osteomyelitis. A double hook plate was used to rigidly stabilize the distal radial fracture after anatomical realignment. An autogenous cancellous bone graft was used where a lateral architectural defect remained after reduction. Culture of the fracture site showed Staphylococcus sp., which responded to chloramphenicol therapy. Fracture union and resolution of osteomyelitis occurred by 9 weeks after surgery, and the dog had no lameness and a normal muscle mass 22 weeks after surgery. The double hook plate provided rigid internal fixation of the radial fracture, allowed a rapid return to function during osteosynthesis, and minimal interference of antebrachiocarpal joint function occurred.