Management of severe stifle trauma: 2. Periarticular fractures

Abstract

Practical relevance: Periarticular stifle fractures are uncommon but challenging injuries to treat. There may be concurrent damage to the ligaments and stabilising structures of the stifle joint itself, which should also be evaluated (see Part 1 of this article series). Improved knowledge of the fixation options and biomechanical challenges of these injuries will aid clinical decision-making and effective repair. Clinical challenges: Due to their nature, periarticular fractures may have small juxta-articular fragments, which require additional thought to address during stabilisation. In juvenile animals, these fractures typically involve the physis and often can be managed with cross pin fixation. In adult cats, locking fixation, specialised plates or external skeletal fixators can be utilised to address the juxta-articular fragments. Readers should also be aware of patellar fracture and dental anomaly syndrome (PADS), where cats develop insufficiency fractures affecting the patella and proximal tibia. A careful oral examination should be performed in affected patients, as these cats may have persistent deciduous teeth. Close attention should be paid to preoperative radiographs for evidence of chronicity of the injury including sclerosis of the patella, remodelling and blunting of the fracture lines. Aims: The aims of the article are to review the current literature surrounding periarticular fractures of the stifle joint and to summarise the diagnosis, treatment, outcome and complications of each fracture type. As well as discussing general fracture fixation and biomechanical principles applicable to both dogs and cats, information is provided on specific issues facing cats, such as PADS. Evidence base: Published data is limited, with reports including only a small number of cats. The information and recommendations in this article have therefore been drawn from a combination of the available literature and the authors’ clinical experience.

Feline Femoral Fracture Fixation: What are the options?

“…Use of a tied-in intramedullary pin is recommended if only one additional half pin can be placed in the distal fragment. 99…”

“…As discussed earlier, options for fixation of the supracondy-lar portion include reconstruction plates, supracondylar plates or locking plates, the last of which can provide good stability when placed bilaterally. 99 If comminuted, the repair is often very challenging. Large fragments can be secured with pins; small fragments may require removal but, wherever possible, the largest components of the condyle should be compressed together with a lag screw.…”

“…Most distal femoral fractures are located within the stifle joint capsule, which can make them difficult to differentiate from joint instability on clinical examination alone, 99 depending on the experience of the clinician. Careful palpation of the patella and patellar ligament while paying particular attention to any crepitus can help with identification of these fractures.…”

“…Supracondylar fractures can be surgically challenging as even simple fractures may not have inherent rotational or shearing stability and the distal fragment is inevitably short. 100 While stabilisation with dynamic intramedullary cross-pinning has been described, 101 rigid stabilisation with a bone plate, external skeletal fixator or angle-stable interlocking nail 81 is recommended, with care being taken not to penetrate the stifle joint 99 or impinge patellar tracking.…”

“…The caudal pulling forces of the hamstrings tend to promote under-reduction of the distal femoral condyle, and therefore it is important to apply traction and compression to correctly reduce it. 99 Reduction is best achieved with the stifle in extension. Some surgeons advocate placement of pointed reduction forceps between the intercondylar notch and the cranial cortex just proximal to the trochlea; 3 however, this should be performed with caution in very young animals with soft bone.…”