Free-form External Fixators for Radius and Ulna Fractures in Small and Toy Breeds
S.C. Roe; J. Carr; D.J. Marcellin-Little
Fractures of the radius and ulna in small and toy breed dogs present mechanical and biological challenges. It is our experience that closed or limited open reduction and free-form external fixation has been successful in achieving union with minimal complications. We reviewed 21 dogs with 24 radius and ulna fractures managed with a free-form external fixator at the NCSU Veterinary Teaching Hospital between 1994 and 2006. Italian Greyhounds were the most common breed (n=6). The average weight was 3 kg (0.7-5.6 kg), and the average age was 0.84 years (0.4-2 yrs). In one of the bilateral cases, the fractures occurred simultaneously. In another, they were 2 weeks apart, and another, 8 months. Closed or open reduction was used depending on the difficulty of reduction. Positive profile threaded acrylic fixation pins (0.9 or 1.15 mm) were used primarily. In most cases, holes were drilled prior to pin placement. Frame configurations were primarily unilateral and medial, with 3 pins proximal and 3 pins distal. When the distal fragment was small, a more cranial pin direction was used for one pin. Epoxy putty was used to connect the pins. The frame was bandaged for 7-14 days, and then usually left uncovered, to facilitate care of the pin tracks. Clients were advised to keep the patient strictly confined until radiographic assessment at 6-8 weeks. One bilateral case was lost to follow-up. One fracture developed severe osteomyelitis, and the limb was amputated. Fixators were removed a median of 8 weeks after placement (5-20 wks).