Femur Fracture Fixators

Unilateral external skeletal fixation (ESF) is a technique used to stabilize bone segments or joints with half pins inserted through the skin and secured to an external frame. ESF is a less invasive technique than plate or pin fixation and can be adjusted or reinforced postoperatively. The semicircular ESF system enables multiplane half-pin insertions. This article reports the outcome of 18 femoral fracture repairs in 16 dogs using the unilateral semicircular ESF system. The dogs were 2 months to 10 years of age and fracture configurations were oblique, comminuted, or transverse. Eight dogs had complications after fixator application. Pin tract drainage during healing was the most common complication and typically responded to improved cleaning of the pin–skin interface and administration of oral antibiotics. Three dogs had mild to severe periosteal reactions that gradually resolved after fixator removal. Eight dogs used their limbs immediately after awakening from anesthesia. In the other 8 dogs, time to first use ranged from 1 to 4 days. One fracture failed to achieve union and a plate was used to revise and stabilize it, with clinical success 4 months later. Functional outcome was excellent in 13 femurs, good in 4, and poor in the 1 case in which nonunion occurred. The authors conclude that the unilateral semicircular ESF is a viable option for femoral fracture repair in dogs.

Commentary: This article describes the use of a novel carbon-fiber curved arch to secure external fixator pins in the treatment of canine femoral fractures. An open approach was used to align the bone, and then negative-profile pins were inserted from the lateral to medial aspects of the femur. An open approach is counter to biologic fixation, but the authors documented rapid return to weight bearing following surgery, perhaps made possible by avoiding the penetration of muscle masses by the pins. If this device is used in a closed fashion, avoidance of the sciatic nerve would be imperative. Use of linear external fixators on the femur has always been challenging due to the inability to apply pins from the medial side as well as the large muscle mass. The described system allows better 3-dimensional planes of pin placement as compared with standard linear external fixator systems.—Jonathan Miller, DVM, MS, Diplomate ACVSManagement of femoral fractures in dogs with unilateral semicircular external skeletal fixators. Yardimci C, Ozak A, Nisbet HO. VET SURG 40:379-387, 2011.