Substantial ankle varus did not remodel. Radiologically, the tumor arises from the surface of the bone and the cortex and medullary cavity of the lesion is continuous with the cortex and medullary cavity of the bone. A CT scan can be very helpful in confirming this and may thus confirm the diagnosis. MRI is usually not necessary for diagnosis but may help define the nearby neurovascular structures in preparation for surgery. MRI will also allow precise measurement of the thickness of the cartilage cap on the lesion, which is an indicator of the potential for amlignant degeneration.
Treatment consists of simple excision by osteotomy through the base of the stalk.
Surgeons do not need to remove every vestige of the stalk or base of the tumor to achieve complete resolution of the symptoms. The neurovascular bundle may be very near the intended osteotomy site. Damage to the neurovascular structures of the foot is not an acceptable complication from what should be a simple removal of a benign bone tumor. Surgical treatment should be deferred until the patient is at or near skeletal maturity, if possible. The lesions are less likely to recur and are better defined so that complete removal can be easily accomplished and damage to the growth plate as well as recurrence can be avoided.