Splitting of the common peroneal nerve by an osteochondroma: two case reports

Multiple exostoses is an autosomal dominant disease in which bony protuberances arise from the metaphyseal periphery. Most are asymptomatic but occasionally the tumors become troublesome, causing irritation to the surrounding tissues. While nerve compression by an adjacent osteochondroma has been reported, to our knowledge there are no reports of the tumor growing through the mid-substance of a nerve. This article reports two occurrences of an osteochondroma of the proximal fibula that was noted at surgery to grow through the common peroneal nerve, splitting it into two limbs. By reporting these cases, it is our hope to alert surgeons that this problem may occur, and care should be taken to identify the entire nerve prior to removal of the osteochondroma.