Pathological fracture of the radius secondary to an aneurysmal bone cyst in a horse.

摘要

Aneurysmal bone cysts (ABCs) are expansive lesions of bone that arise from disturbances in the bone marrow vasculature (Jubb et al. 1985). They are not neoplastic but may be confused with bone tumours both clinically and radiologically. They are rare in domestic animals and have been recorded in the dog (Schrader et al. 1983; Duval et al. 1995), cat (Walker et al. 1975), cow (Belknap et al. 1992), pig, llama and horse. Six cases of ABCs in the horse have been reported, with 4 affecting the mandible (Blackwell et al. 1985; Purdy 1985; Lamb and Schelling 1989; Jackman and Baxter 1992) and 2 affecting the long bones (Steiner and Rendano 1982; Thomas et al. 1997). The pathophysiology of ABCs is poorly understood. They are usually found in rapidly growing young animals, affecting the long bones in dogs and skull in horses. Aneurysmal bone cysts are not uncommon in man and generally occur before puberty and affect the long bones, skull, vertebrae and ribs (Biesecker et al. 1970; Ruiter et al. 1977). In this case, the presenting complaint was an acute lameness of the right forelimb.