Unilateral Repair of an Avulsion Fracture of the Caudal Cruciate Ligament Origin Combined with a Ruptured Cranial Cruciate Ligament in a Dog

Abstract Caudal cruciate ligament (CaCL) femoral avulsion fractures are rarely documented, and a true incidence is unclear. A literature search revealed very few cases of a CaCL avulsion fracture or rupture combined with a cranial cruciate ligament (CrCL) rupture. Only a single case report described surgical treatment of this combination by fragment removal and stifle stabilization with an extracapsular suture. A 1-year-old female spayed Labrador Retriever presented with a hindlimb lameness. Examination revealed cranial drawer of the stifle, consistent with CrCL rupture. Stifle effusion, as well as a bone opacity seen in the trochlear groove, was evident on radiographs. At surgery, arthrotomy revealed a torn CrCL as well as an avulsion fracture of the CaCL origin from the medial femoral condyle. The avulsion fracture was reduced, and three 0.035-inch Kirschner's wires (K-wires) were placed in a divergent fashion through the fragment into the medial femoral condyle. A tibial plateau leveling osteotomy (TPLO) was then performed. Six-week recheck radiographs showed good healing of the TPLO as well as the repaired avulsion fracture, despite breakage of one of the K-wires. The dog was mildly lame at the 6-week follow-up and subsequently improved to clinically normal on the limb at 8-month follow-up with optimal bone healing on radiographs. To the authors' knowledge, this is the first case report to describe a CaCL avulsion fracture repair with K-wires combined with a TPLO for a torn CrCL, with an excellent clinical outcome.