Osteoid Osteomas of the Foot and Ankle: A Study of Patients Over a 20-Year Period
Osteoid osteomas (OOs) are common benign bone tumors that seldom occur in the foot or ankle. Patients typically complain of pain that is worse at night and is relieved with use of nonsteroidal anti-inflammatory drugs. Previous studies of treating these lesions in the foot and ankle have been limited to case reports.
We retrospectively reviewed all cases of a histologically confirmed foot or ankle OO treated surgically or with an interventional radiologic procedure between 1990 and 2010. Thirteen (12 male, 1 female) patients had a foot or ankle OO. The most common site was the talus (n = 5). Ten lesions were treated surgically, 3 with radiofrequency ablation (RFA). Surgical patients required 3 weeks of restricted weight-bearing, whereas patients treated with RFA had no weight-bearing restrictions. At final follow-up, all patients reported complete pain relief and return to previous activities.
Surgical curettage and RFA provided excellent symptom relief in patients with a foot or ankle OO. We recommend RFA for lesions with diagnostic imaging. RFA is contraindicated for lesions near a major neurovascular bundle. Surgeons should carefully measure the distance from lesion to articular cartilage and use the treatment that minimizes damage to the cartilage.
We believe that surgical resection and RFA provide equally effective treatment outcomes for patients with foot and ankle OOs. The major contraindication to RFA is anatomical proximity (<1.5 cm) to a major neurovascular bundle. Theoretically, articular cartilage can be damaged during RFA.21,25 To our knowledge, there have been no reported complications involving articular cartilage damage. However, surgeons should carefully measure the distance from lesion to articular cartilage and select the treatment option that will cause the least amount of damage to the cartilage.
Two limitations of this study are its retrospective nature and relatively small number of patients. As all the lesions in the study were treated surgically or with RFA, we are unable to comment on the natural history of untreated foot and ankle OOs. Although there were no recurrences, late recurrence is possible with longer follow-up. However, we think this study will not only increase familiarity with the imaging features of OOs involving the bones of the foot and ankle, but it will help clinicians formulate optimal treatment plans.
Overall, OOs are relatively common benign bone tumors, with limited reports of their occurrence in the foot and ankle. There should be a high index of suspicion for the diagnosis if a patient presents with the symptoms classically associated with the tumor, but in some cases the diagnosis can be challenging. Proper imaging is essential for prompt and accurate diagnosis.
