Sarcoma of the proximal portion of the tibia in a dog 5.5 years after tibial plateau leveling osteotomy

Osseous neoplasia was identified in the proximal portion of the tibia and distal portion of the femur in an 11.75-year-old spayed female German Shepherd Dog. A tibial plateau leveling osteotomy, followed by application of a metal plate, had been performed on the affected limb 5.5 years earlier. Areas of osteolysis and periosteal proliferation were seen radiographically, with an intense area of osteolysis directly beneath the metal plate. Histologically, the tumor was identified as a poorly differentiated sarcoma. Extracellular and intracellular debris was seen histologically, and energy-dispersive x-ray analysis confirmed that this debris was metallic. On visual examination, areas of the underside of the metal plate that had been in contact with bone had a dull, roughened appearance, and scanning electron microscopy of these areas revealed multiple corrosion pits. The plate was strongly magnetic, suggesting that it contained ferrite, and metallographic examination of the plate revealed substantial differences in the chemical makeup of various parts of the plate. Microstructure analysis revealed that the plate consisted of an austenite matrix with a large fraction of ferrite. The plate was determined to be a cast 316L stainless steel implant, but it did not meet American Society for Testing Materials standards for implant-grade materials. The possibility that implant corrosion might have played a role in tumor development is of concern; however, a definitive association was not established.     

A lag-screw technique for bridging of the medial aspect of the distal tibial physis in horses

A lag-screw technique for transphyseal bridging of the medial aspect of the distal tibial physis in foals with tarsal valgus deformities and results of the technique in 11 foals (6 with bilateral tarsal valgus deformities and 5 with unilateral tarsal valgus deformities) are described. Briefly, horses were anesthetized, and a single stab incision was made through the skin to the underlying bone over the most distal aspect of the medial malleolus. A 20-gauge needle was placed in the incision to guide screw placement, and a lag screw was inserted parallel to the medial cortex of the tibia under radiographic guidance. Screws were removed when the tarsal valgus deformity was clinically assessed to have improved by at least 80%. Clinically, all horses had evidence of a tarsal valgus deformity of > 7 degrees prior to surgery. Mean age at the time of lag-screw implanation was 220 days (range, 116 to 364 days). Mean time the implant was in place was 62 days (range, 39 to 89 days). The tarsal valgus deformity resolved in all 11 horses with excellent cosmetic results.     

Osteosarcoma of the tibia 6 years after tibial plateau leveling osteotomy

A 7 yr old spayed female mastiff presented for examination of a left pelvic limb lameness of 3 mo duration. Six years previously, the dog had undergone tibial plateau leveling osteotomy (TPLO) surgery of the left pelvic limb for the treatment of cranial cruciate disease. On presentation, the dog had a painful and swollen proximal tibia. Following investigation, a diagnosis of osteosarcoma of the proximal left tibia at the site of the previous TPLO surgery was made. This is the first reported case of osteosarcoma following TPLO using an implant other than the Slocum plate.     

Primary osseous melanoma in the tibia of a dog

An 18-month-old, female Cane Corso dog was presented with a suspected primary tumor of the tibia. Plain radiographs and computed tomography (CT) of the tibia were highly suggestive of a primary bone neoplasm. A diagnosis of malignant melanoma was made by cytology. Total body survey radiographs, CT scan of the thorax, and abdominal ultrasound excluded the presence of neoplastic lesions other than in the tibia. Limb amputation was performed. Histology and immunohistochemical analysis of the tibial neoplasm confirmed the diagnosis of a melanoma with secondary metastasis to the popliteal lymph node. The dog was alive and in good physical condition 43 months after surgery.     

Limb salvage in a dog with chondrosarcoma of the tibia

Limb salvage was accomplished by using a frozen allograft bone and arthrodesis of the stifle joint in a 5-year-old male German Shepherd Dog with a chondrosarcoma in the proximal tibia. At 17 months after surgery, limb function was satisfactory, and thoracic radiography did not reveal evidence of pulmonary metastases.     

An analysis of canine hair re-growth after clipping for a surgical procedure

Hair growth and replacement have been studied extensively in humans, sheep and laboratory rodents, but in dogs and other mammalian species few studies have been published. The objectives of this study were: (1) to determine the time required for the hair to re-grow in dogs after clipping for a surgical procedure; (2) to define whether the season of the year influenced the period of time required for re-growth and; (3) to determine if season might influence the telogen: anagen ratio. Eleven Labrador retrievers were recruited during spring, 10 during summer, six during autumn and 10 during winter. Hairs re-grew to their preclipped length in 14.6 weeks, 14.5 weeks, 13.6 weeks and 15.4 weeks when shaved in the spring, summer, autumn and winter, respectively. The differences in these values were not significant suggesting that season has no effect on the rate of hair re-growth in Labrador retrievers housed indoors (P = 0.12). The mean values for the telogen: anagen ratio in each season were: 5.2 (spring), 6.1 (summer), 9.5 (autumn), and 5.3 (winter). The differences in these values also were not significant (P = 0.89). The percentage of hairs in telogen was over 80% in all four seasons.     

Closure after injury of the distal femoral growth plate in the dog

Distal femoral growth plate separations were created and repaired using pin–fixation in 24 immature dogs. In 16 dogs, destroyed 10 weeks after surgery, the growth plate had closed. Of eight dogs destroyed from 1 to 4 weeks after surgery, seven had a indication of premature closure while one (destroyed at 1 week) had only injury to the plate.     

Transverse cordotomy and cuneiform cartilage amputation for the management of laryngeal paralysis in a dog

This paper describes the novel approach of transverse cordotomy and cuneiform cartilage amputation for the surgical management of laryngeal paralysis in a dog.     

Preliminary experiences of the triple tibial osteotomy procedure: tibial morphology and complications

O bjective : To document the effect of variable tibial morphology on the planning and execution of the triple tibial osteotomy (TTO) procedure in dogs and complications encountered while becoming familiar with the technique.
M ethods : The records of 21 consecutive cases that had a TTO performed were reviewed. Preoperative tibial morphology was assessed. Modifications in the described technique and complications were documented. Postoperative outcome was evaluated using a client-based questionnaire.
R esults : The size of the tibial wedge ostectomy was modified because of variable tibial morphology in four dogs (19 per cent) to avoid over or under correction of the tibial plateau angle (TPA). Intraoperatively, fracture through the caudal tibial cortex occurred in nine cases (41 per cent) and through the distal tibial crest cortex in four cases (18 per cent). Major complications occurred in five (23 per cent) of cases with four (18 per cent) requiring further surgery. The client questionnaire results demonstrated significant improvements in all parameters and no significant difference from the preinjury status.
C linical S ignificance : TPA measurement is recommended when planning a TTO to avoid over or under correction of the TPA. Despite frequent minor complications, it appears that the TTO is an effective procedure for management of cranial cruciate ligament rupture in the dog.     

Prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with acute thoracolumbar disk extrusions: 112 cases

OBJECTIVES: To determine prognostic indicators for time to ambulation after surgical decompression in nonambulatory dogs with intact pain sensation and acute Hansen type-1 disk extrusions. STUDY DESIGN: Retrospective clinical study. ANIMALS: One-hundred twelve dogs with Hansen type-I disk extrusions that had decompressive hemilaminectomy or dorsal laminectomy. METHODS: All dogs had thoracolumbar disk extrusion and were nonambulatory with intact pain sensation at admission. Variables considered included age, weight, voluntary motor function at time of anesthetic induction, glucocorticoid use, times from onset of nonambulatory status to admission and surgical decompression, time in hospital to surgical decompression, anesthetic time, surgical time, number of contrast injections required to perform a diagnostic myelogram, postoperative pain sensation, and postoperative voluntary motor function. Time to ambulation was defined as the number of days from surgical decompression until the dog was able to stand and take a series of steps without assistance. RESULTS: One-hundred seven dogs (96%) were able to ambulate within 3 months. The mean time to ambulation was 12.9 days and was significantly shorter if dogs had postoperative voluntary motor function (7.9 days v 16.4 days, P <.0001). No other variable had a significant association with time to ambulation. CONCLUSIONS: Few perioperative variables have prognostic value for return to ambulation. Nonambulatory dogs with intact pain sensation and Hansen type-1 disk extrusions in the thoracolumbar spine that are treated with surgical decompression have a favorable prognosis. CLINICAL RELEVANCE: The presence of postoperative voluntary motor function is a favorable prognostic indicator for early return to ambulation.