Medullary decompression of the radius as treatment for lameness in a horse

Increased intraosseous pressure (IOP) is a well-characterized source of pain in humans that can be successfully treated by medullary decompression. This report describes the clinical and diagnostic findings, treatment and successful outcome of a horse with a four week long, non-weight bearing lameness secondary to suspected traumatically-induced increased IOP in the left radius. Scintigraphic examination characterized by severe increase in radiopharmaceutical uptake within the affected radius aided in the initial localization of the source of lameness. Decompression of the affected radius was performed by drilling two 3.2 mm tracts through the lateral bone cortex into the medullary cavity. Intramedullary pressure in the radius was measured (37-39 mmHg). Dramatic clinical improvement was observed after surgical decompression of the affected bone and the horse showed full recovery and returned to previous exercise use by 12 months after treatment. Gradual decrease in radial radiopharmaceutical uptake was observed during the following year. Increased IOP should be considered as a cause of lameness in horses and scintigraphic examination may aid in its diagnosis. Medullary decompression may be a successful treatment in some cases.