Use of a hybrid external skeletal fixator construct for managing tibial tuberosity avulsion fractures in three dogs

Authors: 
Valentine D Verpaalen, Daniel D Lewis
J Am Vet Med Assoc. 2021 May 15;258(10):1098-1108.

Case description: 3 juvenile (4 to 5 months of age) medium- to large-breed or crossbred dogs were evaluated for sudden unilateral non-weight-bearing lameness in a pelvic limb after a fall during strenuous activity.

Clinical findings: All dogs had non-weight-bearing lameness (n = 2) or bore minimal weight (1) on the affected pelvic limb, had soft tissue swelling over the cranial aspect of the stifle joint in the affected limb, seemed to resist manipulation of the affected joint, and had tibial tuberosity avulsion fracture confirmed with radiography.

Treatment and outcome: Each dog underwent surgical fracture reduction and stabilization with a hybrid circular-linear external skeletal fixator construct with interfragmentary Kirschner wires used to stabilize the avulsed tibial tuberosity. Successful fracture reduction and stabilization were achieved, and only minor postoperative complications occurred. Construct removal 2 weeks postoperatively resulted in no displacement of the tibial tuberosity in 2 dogs and only minor proximal displacement in the remaining dog, allowed for continued unencumbered growth through the apophysis and proximal tibial epiphysis in all dogs, and did not result in tibial conformational anomalies. Clinical outcome was considered excellent in 2 dogs with complete resolution of lameness and good in 1 dog with subsequent occasional mild lameness.

Clinical relevance: Our findings suggested that the described hybrid external skeletal fixator construct could be used as a minimally invasive strategy to successfully manage tibial tuberosity avulsion fractures in dogs and may be advantageous in very young medium- to large-breed dogs in which premature closure of the tibial tuberosity apophysis could result in distal translocation of the tibial tuberosity and deformity of the tibial plateau.