Working Dog Saved from Amputation

Apr 14, 2017 / Practitioner Updates

Flits police dog

Surgeon Shares Steps to Repair Elbow Fracture

Case Information

Flits is a 10-year-old MI German Shepherd police dog that sustained a highly comminuted, irreducible, proximal metaphyseal articular fracture of the left ulna that was closed with marked soft tissue swelling of the antebrachium. The fracture was sustained when Flits fell through a roof on an active mission. Initially, Flits’s owners were told that, due to the severity of the injury, the limb would need to be amputated. While amputation is a valid treatment option, for patients who require full limb function, definitive fixation is recommended despite the development of osteoarthritis long-term in the elbow.

Initial Stabilization

With any trauma patient, initial assessment and stabilization is an important component to determine the severity of injuries, evaluate for multi-organ involvement, and allow appropriate recommendations to be made in regard to diagnosis, prognosis, and cost to the client.

Imaging and Surgical Planning  

Imaging is an extremely important component of fracture management. Imaging of the trauma patient usually begins with plain orthogonal radiographs after localization of the site of fracture disease. Although radiographs will reveal most fractures, subtle fractures and fissures (those involving the articular surface and fracture morphology) may not be readily apparent.

In these instances, cross-sectional imaging, such as magnetic resonance imaging (MRI) or computed tomography (CT), is warranted to allow planning for surgical intervention. Inclusion of both joints allows the contralateral limb to be utilized as a normal control. In Flits’s case, CT and 3D-modelling and reconstruction, which allow superior imaging of bony structures, were used next.

x-ray veterinary imaging

Surgical Intervention

x-rayFirst, minimally invasive arthroscopic assessment of the joint was performed to more thoroughly evaluate the congruence of the joint and allow the effect of fracture reduction to be assessed at the level of the articular surface. From prior imaging, it was evident that Flits had an incidentally diagnosed component of elbow dysplasia, an Un-united Anconeal Process (UAP) of the left elbow with secondary osteoarthritis. This was treated by removal via an arthroscopically assisted approach.

Arthroscopy minimized patient morbidity, which in turn decreased hospitalization time and post-operative costs. The procedure was minimally invasive; the small arthroscope and instrument portal incisions transect fewer nerve endings in the highly innervated joint capsule of the elbow, thus reducing postoperative pain. A minimally invasive approach also allows periodic re-evaluation of the joint to monitor therapy or disease progression, which can be not only diagnostic but also therapeutic. Additionally, recovery is faster with minimally invasive procedures, allowing an earlier return to function and preservation of range of motion. Flits was weight-bearing, walking, and using the limb well the morning after surgery.

The main benefit of arthroscopy in this case was magnification and illumination of the complex elbow joint, allowing better visualization of intraarticular surfaces and structures than conventional open arthrotomy. There is also less risk of infection than with open surgery. The video connection to the arthroscope allows all members of the team (residents, interns, and students) in the surgical suite to observe the procedure in real time, which is also a great teaching tool to aid understanding and extrapolate imaging findings pre-operatively to those appreciable at the time of surgery.

x-rayAfter removal of the UAP from the caudal aspect of the humero-ulna joint and fracture distraction and reduction, a laterally applied locking plate was utilized for fixation of the proximal ulna. Using this method, screws actually lock into the plate forming what is known as a fixed-angle construct. By locking screws into the plate, axial forces are transmitted over the length of the plate and the risk of secondary loss of the intraoperative reduction is reduced, which is especially important when the time to healing is expected to be prolonged, as in Flits’s case.

A fixed-angle construct provides advantages in multi-fragmentary fractures where traditional screw purchase may become compromised over time. An aspirate of bone marrow-derived stem cells and an autologous bone graft was then obtained from the proximal humerus and mixed with a frozen allograft. This was then mixed and inserted within and around the fracture to aid and promote healing of the bone. The fracture hematoma at the fracture site was left undisturbed to maximize the dog’s osteogenic potential.

Follow-Up Care

Flits was bandaged, and a lateral spica splint applied to the limb. The expectation is to maintain the splint for a period of 2 to 4 weeks, with regular bandage changes performed at his referring veterinarian. He will then require aggressive physical therapy and rehabilitation to maximize range of motion of the elbow. The expectation is that healing will be complete around 12 to 16 weeks and he will return to his active duties in the field. He is currently doing extremely well and is fully weight-bearing on the limb.

—Dr. Dan Duffy, BVM&S(Hons.), MS, MRCVS, DACVS-SA