Thoracic stenosis causing lateral compression of the spinal cord in two immature Dogues de Bordeaux.

This case report describes a novel developmental vertebral malformation in two young Dogues de Bordeaux, which was diagnosed by magnetic resonance imaging. Both dogs were treated surgically with reasonable success.

Radiographic and clinical features of carpal varus associated with chronic sprain of the lateral collateral ligament complex in 10 dogs.

Lameness associated with carpal varus deformity was recognised in 10 dogs, eight of which were Dobermann Pinschers. The dogs had a mean age of seven years and nine months. Carpal varus was usually bilateral with concurrent carpal hyperflexion and pronation. Carpal varus was present prior to the onset of lameness in four cases. With stress radiography the median angle of varus deviation in all carpi was 14.6 degrees , and an increase in the size of the ulnar /ulnar carpal bone joint space was seen in six of the seven dogs. Radiographic changes included: enthesophyte formation at the proximolateral aspect of metacarpal V, periarticular soft tissue swelling, especially lateral, bone proliferation at the carpometacarpal joint I and enthesophyte formation at metacarpophalangeal joint V. Four dogs were admitted for problems other than carpal varus and lameness was not treated. Five dogs were treated with nonsteroidal anti-inflammatory drugs, but lameness was not completely resolved and became exacerbated with exercise. One dog was successfully treated by pancarpal arthrodesis.

Impaction grafting with morsellised allograft and tricalcium phosphate-hydroxyapatite: incorporation within ovine metaphyseal bone defects.

An ovine model was used to investigate the in vivo properties of impacted tricalcium phosphate-hydroxyapatite (TCP-HA) aggregates, varying in chemical composition (ratio of TCP to HA) and particle size distribution (8 versus 3 particle size ranges). All pellets were impacted to a standard compactive effort. Eight sheep underwent implantation of pellets in 4 metaphyseal defects in both rear limbs. Treatment groups consisted of: (1) allograft (clinical control). (2) 50/50 allograft/80% HA/20% TCP in 8 particle size ranges, (3) 50/50 allograft/80% TCP/20% HA in 8 sizes and (4) 50/50 allograft/80% HA/20% TCP in only 3 sizes of particles. Healing of defects was evaluated at 14 weeks with computed tomography, histology and histomorphometry. The computer tomography (CT) density measured in all defects containing synthetic agents was higher than in defects filled with allograft alone (p<0.01). Defects containing 8 sizes of 80% HA/ 20% TCP granules (group 2) achieved lower histological scores and contained less bone than the clinical control (p<0.05), whereas groups 3 and 4 did not differ from the control. Although all synthetic agents were osteoconductive, our results suggest that increasing the ratio of TCP over HA and limiting the number of particle size ranges to 3 instead of 8 improve the performance of impacted aggregates as graft expanders. Evaluation under loading conditions of morsellised allograft expanded with 80% TCP/20% HA (BoneSave) in 3 particle size ranges is warranted.

Avulsion of the tibial tuberosity with separation of the proximal tibial physis in seven dogs.

Seven dogs developed avulsions of the tibial tuberosity apophysis in combination with a fracture of the proximal tibial physis. Six of them were small terrier breeds, treated by internal fixation using two Kirschner wires and a tension band in five cases, and crossed Kirschner wires alone in the other. The seventh case was managed conservatively. The tension band repair was simple, provided adeqate fixation and avoided the placement of implants across the proximal tibial physis.

An ovine model to evaluate the biologic properties of impacted morselized bone graft substitutes.

The objectives of this study were to develop and evaluate a bone-defect model to study the biologic behavior of biomaterials being considered for impaction grafting in revision hip arthroplasty. A miniature impactor was designed to produce pellets of aggregates at a standard compactive effort. In Phase 1, 22 sheep underwent implantation of pellets into six metaphyseal defects in both rear limbs. In Phase 2, eight sheep underwent surgical implantation of four pellets in metaphyseal defects. Defects were sealed with polymethylmethacrylate in both phases. Healing of the defects was evaluated at 7 weeks (Phase 1, n = 11) and 14 weeks (n =19) with computed tomography, histology, and histomorphometry. Complications in Phase 1 included four femoral fractures and migration of cement seals (18/102 defects). No complications occurred in Phase 2. Whereas no difference was found between left and right limbs, osteogenesis and incorporation of biomaterials varied among implantation sites. For comparison of grafting materials, treatment site allocations were randomized according to a Latin square design. This model allows evaluation of several impacted aggregates (including large particles) in the same animal. It is particularly suitable for analyzing the biologic properties of grafting materials prior to evaluation under loading conditions.

Dermoid sinus at the lumbosacral junction in an English springer spaniel.

A dermoid sinus was identified in a springer spaniel that presented with hindlimb neurological deficits. The sinus was continuous with the dura mater at the level of the lumbosacral junction. The presence of hair and debris adjacent to neural tissue had elicited a myelitis. A dorsal laminectomy was required to allow complete surgical resection of the sinus. The dog's neurological status improved after treatment and this improvement was maintained over a five-month follow-up period.

Osteomyelitis of the atlanto-occipital region as a sequela to a pharyngeal stick injury.

An eight-year-old female Belgian shepherd dog was referred for investigation of chronic neck pain. The dog had sustained a pharyngeal injury 12 weeks previously while catching a stick. Radiographs of the cervical spine revealed signs consistent with a septic arthritis of the atlanto-occipital joint and osteomyelitis of both occipital condyles and the atlas. A foreign body was identified ultrasonographically in the retropharyngeal soft tissues, and a stick was surgically removed from a site ventral to the right side of the atlanto-occipital joint. The signs of neck pain started to resolve within a week of surgery.