Primary intraosseous fibrosarcoma in a cat

A case of primary intraosseous fibrosarcoma of the left femur in a cat was diagnosed at necropsy following 9 months of managing a fracture of the same bone. Case features were those of probable pathological fracture, fracture repair and ultimate lysis of all but a fragment of the distal femoral epiphysis. Histology revealed closely packed whorls of fibroblasts typical of fibrosarcoma. This neoplasm is rare in the cat.     

Primary intraosseous fibrosarcoma in a cat

A case of primary intraosseous fibrosarcoma of the left femur in a cat was diagnosed at necropsy following 9 months of managing a fracture of the same bone. Case features were those of probable pathological fracture, fracture repair and ultimate lysis of all but a fragment of the distal femoral epiphysis. Histology revealed closely packed whorls of fibroblasts typical of fibrosarcoma. This neoplasm is rare in the cat.     

Avulsion of the lateral head of the gastrocnemius muscle in a cat

A 7-year-old male, castrated, domestic shorthair cat was presented with a plantigrade stance of the left pelvic limb. An avulsion of the lateral head of the gastrocnemius muscle was diagnosed based on clinical examination and radiographic assessment. Surgical reduction and fixation were achieved with modified locking loop sutures through bone tunnels in the supracondylar tuberosity of the distal femur. Additionally, a temporary calcaneotibial positional screw was placed in order to neutralise forces on the gastrocnemius muscle. No postoperative complications were encountered and the cat made a full recovery.     

Ex vivo comparison of one versus two distal screws in 8 mm model 11 interlocking nails used to stabilize canine distal femoral fractures

OBJECTIVE: To compare the structural properties of an 8 mm model 11 interlocking nail (IN) with 2 proximal and 2 distal screws (2/2) to 2 proximal and 1 distal screws (2/1) in an unstable canine fracture model. STUDY DESIGN: Ex vivo biomechanical investigation. SAMPLE POPULATION: Eight pairs of adult canine femurs. METHODS: A simple transverse distal metaphyseal femoral fracture with a 1 cm gap was created. The unstable fracture in 1 femur was repaired with a nail with 2 distal and 2 proximal screws and the paired femur with a nail with 1 distal and 2 proximal screws. Cyclic mechanical testing in torsion was performed to assess fatigue life, peak torque, stiffness, and mode of failure. RESULTS: All 2/1 IN-femoral constructs, but only 2 of eight 2/2 constructs, failed before completion of 50,000 loading cycles. The 2/2 constructs had significantly greater peak torque to failure (P = .002) and longer fatigue life (P = .00003) compared with 2/1 constructs. There were no significant differences in stiffness between 2/2 and 2/1 constructs when the non-failed constructs were compared (P > .5). All constructs failed by screw deformation. CONCLUSIONS: An 8 mm model 11 IN used for fixation of unstable canine distal femoral fractures has a longer fatigue life and is stronger under torsional loads when 2 rather than 1 distal screws are placed. CLINICAL RELEVANCE: When repairing unstable canine distal femoral fractures with an IN system, 2 distal screws should be inserted to avoid catastrophic implant failure before bone healing is achieved.     

猫股骨髁粉碎性骨折的手术内固定

为诊断1只高处坠落导致跛行的患猫,采取了临床基本检查、实验室检查及DR影像学检查,确诊为左后肢股骨髁粉碎性骨折。根据检查结果制定手术治疗方案,采用交叉克氏针配合拉力螺钉进行手术内固定。后期回访患猫骨折断端愈合良好,运动功能逐步恢复,表明上述骨折固定方法有效。     

1例猫股骨骨折的诊断与治疗

猫股骨骨折多因直接外力、患病动物自身骨质等问题而发生。介绍了1例狸花猫股骨骨折的诊断、治疗及术后护理过程,以期对临床实践有一定的借鉴作用。     

Purulent Necrotic Dislocation of the Hip Joint Associated with Umbilical Infection in a Foal

A 42-day-old heavy draft horse fell into sudden astasia. Significant swelling and heat sensation of the left femoral region were observed. Because of a friction sound in the left hip, we supposed that the hip joint was dislocated or the hip bone was fractured. Computed Tomography (CT) examination showed that the left hip joint was dislocated and the left femoral head was disjunct. We carried out a pathological autopsy, and made a diagnosis of the foal as fracture of the hip bone and femoral head with suppurative umbilical arteritis. Pathologic changes in the umbilical artery and hind leg were completely unilateral, suggesting that left umbilical arteritis spread to the blood circulation, causing arthritis and dislocation of the hip bone.     

Retrospective study of 38 cases of femur fractures in horses less than one year of age.

Medical records of 38 horses less than 1 year of age and diagnosed as having a fracture of the femoral diaphysis, metaphysis or distal physis were evaluated. Twenty-six foals had fractures of the femoral diaphysis or metaphysis with the most common fracture configuration being comminuted. Twelve foals had distal physeal fractures with the most common fracture configuration being a Salter-Harris type II. Twenty-one foals with fractures of the capital femoral physis, neck or greater trochanter during the same time period were excluded from this study. Surgical repair was attempted in 16 diaphyseal and 2 distal physeal fractures. Most of the diaphyseal fractures were repaired by placing plates on the lateral and cranial surfaces of the bone. Dynamic condylar screw plates or angle blade plates were used for increased bone purchase in 4 foals with short distal fragments. Five foals with distal physeal fractures were treated; 2 were surgically treated by placing an angle blade plate on the lateral cortex, and 3 foals with minimally displaced distal physeal fractures were managed with stall confinement. Eight of the 16 surgically repaired diaphyseal fractures healed. Fracture location and configuration was not a determinant of outcome, but the mean age of foals with successfully repaired diaphyseal fractures was 2 months compared with 4 months for the unsuccessful cases, indicating that the age and size of the foal was important. Long-term follow up revealed that 6 of the 8 successfully repaired diaphyseal fractures had no residual effects of the fracture observed during performance of the horse for its intended use. Only 1 of the 2 surgically repaired distal physeal fractures healed, but this horse was eventually killed because of unthriftiness related to a malabsorption syndrome. Some form of complication developed in 13 of the 18 surgically repaired fractures. Infection was the primary cause of failure. The greatest determinant associated with infection was the inability to control post-surgical seroma formation.     

Open reduction and internal fixation with a locking plate for the treatment of a femoral fracture in a ferret (Mustela putorius furo)

Long bone fractures in ferrets (Mustela putorius furo) are usually traumatic in etiology, and the femur is commonly affected [1]. A 4-year-old, castrated male ferret was examined for acute, non-weight-bearing lameness of the left pelvic limb after presumably falling from its elevated enclosure. Clinical and radiographic evaluation showed a complete, comminuted fracture of the proximal diaphyseal third of the left femur. Open reduction and internal fixation (ORIF) of the left femoral fracture was performed with cerclage wires and a 1.5 mm locking compression plate with associated locking screws. Anatomic reconstruction was achieved, and postoperative radiographs confirmed appropriate fracture fragment apposition, limb alignment, and implant placement. At 9 weeks postoperatively, the ferret was ambulatory with no evidence of lameness, and complete radiographic union was noted. This is the first published report of the use of a bone plate for femoral fracture stabilization in a ferret. Bone plates, including locking plates, could be considered for long bone fracture stabilization in ferrets as an alternative to other methods.     

Bilateral stifle osteochondritis dissecans in a cat

A 9-month-old, castrated male, domestic shorthaired cat was presented for progressive right hind-limb lameness. A diagnosis of osteochondritis dissecans of the lateral femoral condyle was made based on radiographs and physical examination, and was confirmed by right lateral stifle arthrotomy. The cartilage flap was removed, and the underlying bone was curetted. Seven months later, the cat was sound on the right leg but developed a left hind-limb lameness. A similar lesion was found in the left leg and was treated identically. Fourteen months after presentation, the cat was sound on both hind limbs.     

Use of the Cobra Head Bone Plate for Distal Long Bone Fractures in Large Animals A Report of Four Cases

Four long bone fractures with a short distal fragment were repaired with a cobra head bone plate alone (2 cattle) or in combination with a straight, broad dynamic compression plate (2 horses). Three fractures were of the distal femur (1 horse, 2 cattle) and one was of the distal radius (1 horse). The long-term outcome of the three femoral fractures was soundness in one case and mild lameness in two. Although satisfactory bone healing progressed in the horse with the radial fracture, laminitis in the contralateral forelimb necessitated euthanasia at week 6.     

Laminectomy for treatment of cauda equina syndrome in a cat

A 16-year-old spayed female Siamese cat was presented with a history of paraparesis and obstipation. The cat's impaired function was attributed to malalignment of the L7-S1 spine (cauda equina syndrome) and to traumatic fracture of the left femoral neck, with severe degenerative arthritis. Laminectomy resolved the cauda equina problem, and the hip joint was not treated.     

Pathological femoral fracture due to rhabdomyosarcoma in a cat

An eight-year-old neutered male domestic shorthaired cat was presented with non-weightbearing lameness of the right hindlimb. On radiography, a pathological, metaphyseal femoral fracture was apparent, with areas of bony lysis directly surrounding the fracture site. The cat underwent amputation of the limb. Histopathological examination revealed the presence of a tumour of mesenchymal cells with cytoplasm-containing vacuoles which stained positive with the periodic acid-schiff reaction, indicative of glycogen granules that may be found in rhabdomyosarcoma cells. In addition, the tumour cells stained positive for vimentin and desmin on immunohistochemical examination, thus confirming the diagnosis of rhabdomyosarcoma. In spite of the radical surgery performed, the cat was euthanased due to a recurrence at the amputation site four and a half months later.     

Treatment of medial patellar luxation by femoral closing wedge ostectomy using a distal femoral plate in four dogs

This case report describes the treatment of recurrent medial patellar luxation associated with varus deformity of the distal femur by distal femoral ostectomy stabilised using a distal femoral plate. Four dogs (five affected limbs) were included in the study. All cases had received previous surgery for medial patellar luxation but remained significantly lame. All were treated by femoral ostectomy to correct distal femoral varus deformity with application of a distal femoral bone plate. All cases improved following surgery. An excellent outcome was recorded in four of five cases. Lameness persisted in one case despite satisfactory patellar stability as a result of concurrent cranial cruciate ligament deficiency. One case suffered implant failure. Femoral ostectomy is an effective treatment for medial patellar luxation associated with femoral varus deformity. The distal femoral plate provides a convenient method by which to stabilise the ostectomy. Care should be exercised when the 2 mm distal femoral plate is applied.     

Comminuted fracture of the accessory carpal bone removed via an arthroscopic-assisted arthrotomy

A 16-year-old American paint horse gelding was presented for evaluation of a left forelimb lameness grade III/V. Radiographs and computed tomography revealed a comminuted fracture of the accessory carpal bone involving the entire articulation with the distal radius and the proximal aspect of the articulation with the ulnar carpal bone. Multiple fragments were present in the palmar pouch of the antebrachiocarpal joint. An arthroscopic-assisted open approach was necessary to remove all fractured fragments. Subsequently the horse was re-admitted for lameness and was treated successfully with antibiotics and long-term supportive bandaging.     

Dorso-medial ante-brachiocarpal luxation with radio-ulna luxation in a domestic shorthair

An 8-year-old domestic shorthair was admitted with non-weight bearing left forelimb lameness. Examination and radiographs revealed dorso-medial ante-brachiocarpal luxation with palmar luxation of the distal radio-ulnar joint. Primary repair was performed and stabilised using an arthrodesis wire and type Ia Kirschner-Ehmer (K-E) external skeletal fixator (ESF). The cat regained excellent pain-free limb function by 14 weeks with only minor reduction in range of movement. This is the first case report of a cat with distal radio-ulnar joint luxation associated with ante-brachiocarpal luxation. Primary repair of carpal luxation in the cat should be considered before arthrodesis.     

Repair of diaphyseal femoral fractures in cats using interlocking intramedullary nails: 12 cases (1996-2000).

OBJECTIVE: To determine the outcome of femoral fractures repaired with 4.0- and 4.7-mm interlocking intramedullary nails in cats. DESIGN: Retrospective study. ANIMALS: 12 cats with diaphyseal femoral fractures. PROCEDURE: Records of all cats in which the 4.0- and 4.7-mm interlocking nail system was used for repair of diaphyseal femoral fractures at the Animal Medical Center and Florida Veterinary Specialists between 1996 and 2000 were reviewed. Information included signalment, type of fracture, size of the implant, details of the surgery, intra- and postoperative complications, fracture healing, and clinical outcome. RESULTS: Femoral fractures in 12 cats were repaired. Eleven of the fractures were comminuted, with 2 of these being open. Clinical outcome was excellent in 7 cats, good in 3, and fair in 1. One resulted in a nonunion. Complications included screw breakage (1 cat) and fracture distal to the nail (1). Fracture distal to the nail occurred from a second trauma. CONCLUSION AND CLINICAL RELEVANCE: Use of the interlocking nail has been limited in cats because of the small diameter of the medullary canal. Use of the 4.0-mm nail will allow for greater application of this implant in small patients. Results of this study indicate that the 4.0- and 4.7-mm interlocking nails can be used to repair simple or comminuted diaphyseal femoral fractures in cats.     

Osteosarcoma following total hip arthroplasty in a dog

Osteosarcoma involving the distal right femur was diagnosed in a nine-year-old female neutered Rottweiler seven years after total hip arthroplasty had been performed on that limb. The findings were consistent with a primary bone tumour and pathological fracture of the right femoral condyle with loosening of the orthopaedic implant and fracture of the polymethylmethacrylate at the distal aspect of the femoral component. Possible hypotheses to explain the association of osteosarcoma with total hip arthroplasty suggest that the neoplastic process was the result of some derangement of host tissue and the healing process or that the implants or their by-products were carcinogenic. Given the large number of total hip arthroplasties that are routinely performed in dogs, the development of a malignant lesion appears to be an extraordinary complication and may be completely coincidental.     

Cryosurgical Epiphysiodesis in the Dog

Transphyseal freezing of the canine distal femur was evaluated to determine its effect on physeal growth and closure. A specially designed cryoprobe was used to freeze the distal right femoral physis in 17 immature dogs. The left distal femoral physis was sham operated to serve as a control. Dogs were radiographed weekly and euthanized from 2 days to 8 weeks following surgery. The rate of long bone growth decreased in all dogs, and the physis was closed at 6 to 8 weeks.
Histologic studies on the distal femoral physes revealed that immediately after freezing, there was extensive hemorrhage in the epiphysis and metaphysis with disruption of the physis. Inflammation and death of the physeal cartilage followed. Blood vessels invaded the physis, and eventually bone was formed between the epiphysis and metaphysis, resulting in complete and premature physeal closure.     

Osteosarcoma at the site of bone infarction associated with total hip arthroplasty in a dog

OBJECTIVE: To report the occurrence of medullary bone infarction in both femoral canals after bilateral total hip arthroplasty (THA) and the subsequent unilateral development of an osteosarcoma at the site of bone infarction. STUDY DESIGN: Clinical report. ANIMAL POPULATION: An 8-month-old neutered male Samoyed dog. METHODS: Serial physical and radiographic examinations performed at 1, 2, 3, and 5 years after THA. Bone biopsy specimens of the right distal femoral metaphysis were taken 5 years after THA, and a complete necropsy was performed at the time of euthanasia. RESULTS: Bilateral medullary bone infarction was visible in the femoral canals 1 year after THA and remained visible on subsequent evaluations. An osteosarcoma developed in the right distal femoral metaphysis at the site of infarction, 5 years after THA, and was found to have metastasized widely throughout the body. CONCLUSION: Bone infarction may occur in the femoral canal after canine THA. CLINICAL RELEVANCE: Bone infarction may be a predisposing factor for the development of osteosarcoma in the femora of dogs with THAs.