Diagnosis and treatment of hindfoot osteoid osteoma: A therapeutic method for each case

1) to set a reminder of the diagnostic approach to osteoid osteomas (OOs) of the foot; 2) to define the indications of treatment for hindfoot OOs.

5 OOs were checked (3 cases located in the talus and two cases in calcaneus). The diagnosis was established by clinical and imaging data. In all cases, a calcified nidus was identified on CT, perilesional bone oedema on MRI and focal scintigraphic uptake. Two cases were treated with radiofrequency ablation (RFA) and 3 cases with surgical resections: two open surgeries and one arthroscopic surgery. Clinical and oncological outcomes were evaluated at the end of the follow-up.

No complications were reported. The clinical outcome was excellent in all cases. One patient was initially treated with open surgery and then subsequently with RFA due to failure of the procedure. There were no recurrences after an average follow-up time of 4 years and 8 months (range, 1-12 years).

Hindfoot OOs are uncommon and their diagnosis is based on clinical data in conjunction with characteristic imaging findings. Their treatment choices depend on the location of the nidus and relationships with nearby anatomical structures.

The diagnosis of an OO of the hindfoot can be ensured when the epidemiological, clinical and imaging data are compatible with this pathological entity. RFA is indicated for intracortical or cancellous cases in which the nidus is more than 1cm off the skin and significant neurovascular structures. For all other cases an open surgical resection or arthroscopic resection would be the first choice.