Ex-vivo evaluation of the three-column concept in canine thoracolumbar fractures / [Avaliação em ex-vivo do conceito dos três compartimentos em fraturas toracolombares da coluna]

Traumatic events such as a motor vehicle accident or falling from heights are very common in veterinary medicine and often lead to vertebral fracture-luxation with concomitant spinal cord injuries, mostly in the thoracolumbar spine. The purpose of this cadaveric biomechanical study was to determine the feasibility of the three-column concept in canine thoracolumbar segments with induced fractures. Eighteen Functional Spinal Units (FSU) of the thoracolumbar segments (T12-L2) were collected from 18 medium-sized adult dog cadavers and were subjected to flexion-extension and lateral bending tests so that range of motion (ROM) was recorded with a goniometer. Fractures were induced by compressive loads applied by a universal testing machine (EMIC®). After this, specimens were screened using computed tomography (CT) and the fractures were graded as affecting one, two or three columns, and divided into groups A, B, and C, respectively. Post-fracture range of motion (ROM) was compared with the previous results. Groups B and C (with fractures in two or three columns) had instability in the two axes evaluated (P<0.05). The outcomes of this study support the applicability of the three-column theory to thoracolumbar spines of dogs, as the FSUs that suffered fractures in two or more columns showed axial instability.(AU)

Eventos traumáticos, como acidentes automobilísticos ou quedas, são muito comuns na medicina veterinária e, frequentemente, levam a fraturas ou luxações vertebrais, associadas a lesões medulares concomitantes, mais frequentemente na coluna toracolombar. O propósito deste estudo biomecânico em cadáveres foi determinar a viabilidade da teoria dos três compartimentos em fraturas induzidas em segmentos toracolombares de cães. Dezoito unidades espinhais funcionais (UEF) de segmentos toracolombares (T12-L2) foram coletadas de 18 cadáveres de cães adultos de médio porte e submetidas a testes de flexão-extensão e curvamento lateral, de modo que a amplitude de movimento (ADM) foi registrada com um goniômetro. Fraturas foram induzidas por meio de cargas compressivas aplicadas por uma máquina universal de ensaios (EMIC®). As amostras foram submetidas à tomografia computadorizada (TC), e as fraturas foram classificadas como afetando um, dois ou três compartimentos e divididas nos grupos A, B e C, respectivamente. A ADM pós-fratura foi comparada com os resultados prévios. Os grupos B e C (com fraturas em dois ou três compartimentos) apresentaram instabilidade nos dois eixos avaliados (P<0,05). Os resultados deste estudo corroboram a aplicabilidade da teoria dos três compartimentos para segmentos de coluna toracolombar em cães, uma vez que as UEF que sofreram as fraturas em dois ou mais compartimentos apresentaram instabilidade axial.(AU)

Successful use of autogenous bone graft for the treatment of a radius-ulna nonunion in an amputee dog / Uso de enxerto ósseo autógeno no tratamento de uma não união óssea em um radioulna de um canino amputado

Fracture nonunions represent important complications in orthopedic surgeries. Nonunion repairs or bone defects are surgically challenging. Our aim was to describe a nonunion case, which was repaired with rapid bone recovery. An 8-month-old male mixed breed dog that has been previously operated was presented to the Veterinary Medical Teaching Hospital of São Paulo State University, with a right radius-ulna nonunion and an amputated contralateral forelimb. A cancellous bone graft was collected from a partially amputated limb, in order to correct the nonunion, and used in association with a locking plate. After four weeks, the bone graft had been incorporated into the original bone. Clinical union with good weight bearing was achieved after eight weeks.

As não uniões ósseas representam uma importante complicação nas cirurgias ortopédicas. Não uniões ósseas ou defeitos ósseos são um desafio na cirurgia. O objetivo do presente trabalho foi descrever um caso de não união óssea, que foi reparada de forma rápida. Um cão SRD de oito meses, macho, que havia sido operado previamente, deu entrada no Hospital Veterinário da Unesp - Jaboticabal com uma não união óssea em radioulna e o membro contralateral amputado. Um enxerto ósseo autógeno foi coletado do coto do membro contralateral amputado e utilizado junto a uma placa óssea bloqueada para o tratamento. Após quatro semanas, o enxerto ósseo estava incorporado ao osso original. A união clínica e o retorno normal à função foram alcançados após oito semanas.

Partial lateral corpectomy associated with pediculectomy to treat extradural chondroma in a dog: technique description / Corpectomia lateral parcial associada à pediculectomia no tratamento de condroma extradural em um cão: descrição da técnica

This study aimed to describe in detail the surgical technique of partial lateral corpectomy (PLC) associated with pediculectomy to treat an in vitro extradural chondroma. A 12-year old female Cocker Spaniel was seen in the hospital with proprioceptive ataxia of hind limbs associated with extradural compression between the 1st and 2nd lumbar vertebrae. The owner opted for euthanasia since the patient's condition changed due to simultaneous illnesses that culminated in a poor prognosis. The patient's body was formally ceded to perform experimental spinal decompression. The technique was effective to completely remove the epidural mass with minimal manipulation of the spinal cord...

Objetivou-se descrever detalhadamente a técnica cirúrgica de corpectomia lateral parcial associada à pediculectomia no tratamento de um condroma extradural in vitro. Uma cadela de 12 anos de idade, raça Cocker Spaniel, foi atendida com ataxia proprioceptiva dos membros pélvicos associada à compressão extradural entre a primeira e a segunda vértebras lombares. Devido a alterações secundárias decorrentes de afecções concomitantes que culminavam em um prognóstico desfavorável, o proprietário optou pela eutanásia do paciente, e o cadáver foi formalmente cedido para realização de descompressão medular experimental. A técnica utilizada foi eficaz na remoção completa da massa extradural, com mínima manipulação da medula espinhal...

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.