String-Of-Pearls Locking Plate and Cerclage Wire Stabilization of Periprosthetic Femoral Fractures after Total Hip Replacement in Six Dogs.

Abstract
Objective: To report use of, and outcome after, string-of-pearls (SOP(™) ) plate and multiple cerclage wire fixation for treatment of periprosthetic femoral fractures (PFF) associated with total hip replacement (THR) in dogs. Study Design: Case series. Animals: Dogs (n=6) with PFF after THR. Methods: Clinical records (2005-2010) and radiographic evaluations of dogs that had PFF associated with THR, treated with a SOP(™) plate and cerclage wires were retrospectively reviewed. Clinical and radiographic postoperative assessments were performed 4, 12, and 24 weeks postoperatively. Telephone follow-up was performed >12 months postoperatively. Results: Three fractures occurred intraoperatively and 3 occurred postoperatively. One SOP(™) failed at 2 weeks necessitating revision using 2 parallel SOP(™) implants. One dog was euthanatized because of quadriceps muscle tie-down at 6 weeks. Other dogs were free of lameness with full range of motion of the stifle and hip joints at final clinical examination, and positive outcomes were maintained at >12 month telephone questionnaire. There was no evidence of implant failure and positive evidence of fracture healing at final radiographic follow-up. Conclusions: Stabilization resulted in bone healing in 5 dogs; failure in 1 dog may be attributable to technical error. Optimal technical guidelines for use of the SOP(™) in this circumstance are unknown, particularly where fracture configuration varies.