Combined transverse femoral ostectomy and tibial tuberosity distalisation for correction of medial patella luxation and patella alta in dogs.

BACKGROUND: Patella alta is the proximal displacement of the patella within the femoral trochlea. Previous studies have identified an association between patella alta and patella luxation. Distalisation of the tibial tuberosity has been recommended to establish proximodistal alignment of the stifle extensor mechanism with the underlying femur in dogs affected by patella alta. However, a recent canine ex vivo study found stifle extensor mechanism load increased significantly following tibial tuberosity distalisation. Generation of excessive load within the stifle extensor mechanism was avoidable by performing a combined transverse femoral ostectomy and tibial tuberosity distalisation. CASE REPORT: Two dogs presented with acute onset left hindlimb lameness and medial patella luxation. The left patellar ligament length to patella length ratio was 2.37 and 2.39 in each dog (reference range 1.33-2.06), consistent with patella alta. No other stifle abnormalities were identified. Proximodistal stifle extensor mechanism alignment was corrected with a combined transverse femoral ostectomy and tibial tuberosity distalisation. The postoperative ratio of the distance between the proximal pole of the patella and femoral condyle to patella length ratio (A : P) fell within the corrected reference range (1.52-2.44). Follow-up orthopaedic examination and postoperative radiographs at 10-12 weeks demonstrated clinical bone union of the femoral ostectomy and tibial tuberosity distalisation sites. No evidence of medial patella luxation or lameness could be detected. CONCLUSION: A combined transverse femoral ostectomy and tibial tuberosity distalisation technique resolved medial patella luxation with patella alta in two dogs. Additionally, the normal A : P reference interval should be corrected to 1.52-2.44.

The effect of intramedullary pin size and monocortical screw configuration on locking compression plate-rod constructs in an in vitro fracture gap model.

OBJECTIVE: To investigate the effect of intramedullary pin size in combination with various monocortical screw configurations on locking compression plate-rod constructs. METHODS: A synthetic bone model with a 40 mm fracture gap was used. Locking compression plates with monocortical locking screws were tested with no pin (LCP-Mono) and intramedullary pins of 20% (LCPR-20), 30% (LCPR-30) and 40% (LCPR-40) of intramedullary diameter. Locking compression plates with bicortical screws (LCP-Bi) were also tested. Screw configurations with two or three screws per fragment modelled long (8-hole), intermediate (6-hole), and short (4-hole) plate working lengths. Responses to axial compression, biplanar four-point bending and axial load-to-failure were recorded. RESULTS: LCP-Bi were not significantly different from LCP-Mono control for any of the outcome variables. In bending, LCPR-20 were not significantly different from LCP-Bi and LCP-Mono. The LCPR-30 were stiffer than LCPR-20 and the controls. The LCPR-40 constructs were stiffer than all other constructs. The addition of an intramedullary pin of any size provided a significant increase in axial stiffness and load to failure. This effect was incremental with increasing intramedullary pin diameter. As plate working length decreased there was a significant increase in stiffness across all constructs. CLINICAL SIGNIFICANCE: A pin of any size increases resistance to axial loads whereas a pin of at least 30% intramedullary diameter is required to increase bending stiffness. Short plate working lengths provide maximum stiffness. However, the overwhelming effect of intramedullary pin size obviates the effect of changing working length on construct stiffness.

Triple tibial osteotomy for treatment of the canine cranial cruciate ligament-deficient stifle joint. Surgical findings and postoperative complications in 97 stifles.

OBJECTIVE: To report the surgical findings and early post-operative complications of triple tibial osteotomy (TTO) for the treatment of cranial cruciate ligament disruption in dogs. METHODS: Clinical records of 84 dogs (97 stifles) that had TTO procedures were reviewed. Surgical findings and postoperative complications were assessed. A complication was defined as any undesirable outcome resulting from TTO that required further diagnostic investigation or surgical treatment. RESULTS: Mean tibial wedge angle was 13.6 degrees (range 10-20). Incomplete tibial crest osteotomy was achieved in 79% of TTO procedures. Implants were placed in the tibial crest in 67% of stifles. Early postoperative complications occurred in 23% of joints, and included avulsion of the tibial crest (9.1%), fracture at the distal cortical attachment of the tibial crest (6.2%), fibula fracture (4.1%), patellar tendonitis (3.1%), late meniscal injury (3.1%), implant complications (3.1%) and patellar fracture (2.1%). Increased patient age (p = 0.023), increased wedge angle (p = 0.009) and intra-operative fracturing of the cranial tibial cortex (p = 0.017) were significantly associated with postoperative tibial crest avulsion. Implants did not prevent tibial crest avulsion. Increased patient age (p = 0.012) was significantly associated with tibial crest fracture. CLINICAL RELEVANCE: Tibial crest avulsion and fracture are the most common postoperative complications for TTO. Late meniscal injury is uncommon after TTO.

Anatomical investigation of the canine cranial tibial artery.

OBJECTIVE: To investigate arterial vascularity at the level of the proximal tibia as a potential source of the severe intra-operative haemorrhage, which has been previously reported as a complication during tibial plateau levelling osteotomy (TPLO) and triple tibial osteotomy (TTO) surgeries in dogs. To devise a surgical approach for the management of this complication. METHOD: Eight pelvic limbs from five canine cadavers were dissected and the vascular structures at the level of the proximal tibia were identified and photographed. An arterial phase angiogram was performed on a sixth cadaver to further describe the vasculature in situ . Additional dissection was performed on four pelvic limbs to devise a medial surgical approach to the popliteal artery and the cranial tibial artery proximal to the stifle. RESULTS: The cranial tibial artery was identified as the most likely source of profuse haemorrhaging if damaged during proximal tibial osteotomy. Its course and branching are described. A simple medial approach to the popliteal artery at the level of its bifurcation into the cranial and caudal tibial arteries was developed. CLINICAL RELEVANCE: Understanding of the vascular anatomy at the level of the proximal tibia may prevent iatrogenic damage and resulting haemorrhage during TPLO and TTO surgeries. Temporary occlusion of the cranial tibial artery can be achieved through a simple medial approach, proximal to the stifle, in the event of severe haemorrhage associated with TPLO or TTO.

A secure Aberdeen knot: in vitro assessment of knot security in plasma and fat.

OBJECTIVES: To determine the minimum number of throws/turns to form a secure Aberdeen knot and the maximum ear slippage for these knots using three metric polydioxanone coated in fat or plasma. To compare plasma and novel canine liquefied fat as suture coating mediums for in vitro knot security testing. METHODS: Throws/turns were incrementally added until a secure knot was found for plasma and fat. Knots were tensioned until failure and remaining ear length measured. A secure knot was defined as ear slippage 3 mm or less in 20 consecutively tested knots. Ear slippages were statistically analysed. RESULTS: Minimum secure configuration was a 3+1 knot in plasma and fat, and its ear slipped a maximum of 2 mm in plasma and 2.5 mm in fat. A secure 4+1 knot had a maximum ear slippage of 0.5 mm, which was significantly less than that of the 3+1 knot (P<0.0001). Fat coating suture significantly decreases in vitro knot security compared with plasma (P=0.0035). CLINICAL SIGNIFICANCE: The novel fat coating medium should be considered when testing in vitro knot security as it simulates a clinical knot tying environment. A 4+1 Aberdeen knot with a 3 mm ear is recommended to tie a secure Aberdeen knot in any body fluid environment.

Use of a lateral tibial head buttress plate to repair a tibial fracture in a labrador retriever.

A lateral tibial head buttress plate designed for human beings was used to repair a highly comminuted tibial fracture in a two-year-old male labrador retriever caused by a gunshot wound. The plate was placed in a bridging fashion to provide minimal disruption of the fracture site and minimise surgical time.

Omentalisation as adjunctive treatment of an infected femoral nonunion fracture: a case report.

A three-year-old male working border collie with an infected femoral nonunion fracture was managed in a two-stage procedure involving debridement and omentalisation, followed by stabilisation with a bone plate and an autogenous cancellous bone graft. Osseous union was documented radiographically 16 weeks after surgery. Telephone follow-up one year later revealed the dog had returned to full working function without evidence of lameness. To the authors' knowledge, this is the first clinical case described in the veterinary literature using omentalisation as an adjunct to the management of an infected, biologically inactive nonunion fracture.

Stifle joint luxation in the dog and cat: the use of temporary intraoperative transarticular pinning to facilitate joint reconstruction.

Multiple ligament injuries of the canine and feline stifle joint which result in luxation are uncommon. Two cats and one dog, that had sustained such a joint injury were surgically treated. A rupture of the cranial and caudal cruciate ligaments, and at least one collateral ligament was observed in all of the three animals. Prosthetic reconstruction was used, as previously described, in combination with a novel technique of intraoperative placement of a temporary trans-articular pin (TTP) to maintain intra-operative anatomical reduction. TTP placement facilitated maintenance of joint alignment during surgical reconstruction and aided appropriate tensioning of the prosthetic sutures, preventing collapse of femorotibial joint compartments. The TTP was removed prior to closure of the joint allowing immediate post-operative joint mobilisation. Based on assessment by their owners, all the animals made a complete recovery. TTP was considered a relatively simple and effective adjunctive aid for surgical treatment of traumatic luxation of the stifle joint.

Magnetic resonance imaging in the diagnosis and surgical management of sacral osteochondrosis in a mastiff dog.

The clinical, radiographic, magnetic resonance imaging (MRI), surgical and pathological findings related to an osteochondral lesion of the sacrum in a mastiff dog are described. The dog showed chronic signs of pain in its pelvic limbs. Radiography revealed a triangular mineralised opacity at the craniodorsal aspect of the sacrum consistent with sacral osteochondrosis. A T2-weighted spin-echo MRI revealed dorsal and lateral compression of the cauda equina. The osteochondral fragment was removed via a dorsal laminectomy, and the clinical signs resolved. Histological abnormalities in the fragment were consistent with a diagnosis of osteochondrosis.