Elbow dysplasia (Proceedings)

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Elbow dysplasia (Proceedings)

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Oct 01, 2008

The goal of nonsurgical and/or surgical management of the developmental abnormalities of the elbow is to slow the progression OA in the joint and reduce lameness in the patient. The specifics of surgical management are dependent upon diagnosis. For the purposes of this abstract I'll focus on fragmentation of the medial coronoid process (FCP) and osteochondrosis (OCD) of the medial aspect of the humeral condyle. A united anconeal process (UAP) can be treated by removal of the process or internal stabilization of the process but empirically is best treated via a proximal ulnar osteotomy with or without supplemental internal fixation with an interfragmentary lag screw.

Historically, both FCP and OCD are treated by removal of the fragment, debridement of loose cartilage ends adjacent to the primary lesion and, when indicated, microfracture of eburnated bone via arthrotomy or arthroscopy. Both can be associated with kissing lesions on the opposing cartilaginous surface, so a through exploratory of the joint is required. Many have hypothesized that elbow joint incongruency either predisposes dogs to a FCP or persists in conjunction with it. This hypothesis has led some surgeons to incorporate a dynamic proximal ulnar osteotomy or radial head lengthening as a component of treatment. While these are intriguing concepts essentially no peer-reviewed literature exists to support or refute them.

Nonsurgical and surgical management of developmental conditions of the elbow joint frequently leads to unsatisfactory results. In fact, most literature strongly suggests that surgery provides little, if any, advantage to patient prognosis when compared to medical management. Huibregtse et al. studied 22 dogs with forelimb lameness caused by a FCP and provided evidence that elbow OA progressed radiographically in dogs following nonsurgical or surgical treatment. In addition, they performed force plate gait analysis on the dogs and found that there was no difference in limb function between groups. They also found that owners reported a recurrence of lameness in 78% of dogs treated without and 69% of dogs treated with surgery. Mean follow-up time was not reported in this retrospective study. Bouck et. al. studied 19 dogs diagnosed with FCP and/or OCD that were treated medically or surgically using physical, radiographic and force plate gait evaluations and found similar results. One distinct advantage of this study was that is was prospective with a one year follow-up time. They found that regardless of treatment, OA progressed radiographically and range of motion decreased over time. Using force plate gait evaluations they determined that dogs in both groups improved but there was no difference in the amount of improvement between treatment groups. The mean peak vertical force in the affected limb of dogs increased from 40 to 45% of body weight in both groups.

Read et al. studied the largest groups of dogs; reporting on 130 cases of FCP in 109 dogs. This retrospective study focused on the opinion of the dog's owner to report on the degree of lameness and activity before and after treatment. In this study 62 cases were managed nonsurgically and 68 were managed surgically. They found that the degree of lameness improved to some degree in 59% of dogs, regardless of treatment. Lameness, however, persisted in 75.9% of all dogs studied. They also attempted to correlate the degree of lameness at initial presentation to post-treatment outcome, reporting that dogs with mild lameness are less likely to benefit from surgery than dogs with moderate or severe lameness. Tobias et al. performed a long-term evaluation of 35 dogs that had surgery for FCP. Their evaluation included an owner questionnaire, physical exam, and radiographic exam. They concluded that surgical approach and age of patient at the time of surgery did not affect prognosis. Perhaps more interesting, however, was the fact that nearly 65% of dogs still had lameness, 80% had joint pain, and over 95% had joint thickening and a reduced range of motion at follow-up examination. In addition, OA significantly increased in 100% of the cases.