Chronic Lateral Ankle Instability with Os Subfibulare in a Child Treated with Modified Broström/Gould Surgical Technique - A Case Report.

Introduction: Patients with lateral instability of the ankle have a much higher prevalence of an os subfibulare compared with the general population. In children and adolescents with known os subfibulare and chronic instability of the ankle, surgical resection of the os subfibulare and the Broström/Gould procedure to reattach the ATFL to the fibula has been described if conservative therapy fails. Case Report: Our case is about a 10-year-old girl with chronic instability of the ankle and a symptomatic os subfibulare, with additional cystic and edematous changes in the distal fibula in the MRI. Due to the reduced bone density, we assumed a higher risk of anchor pullout with the normal refixation at the distal fibula. Therefore, the surgical technique according to Broström/Gould was modified and the ATFL was refixed on the talar side. Conclusion: In cases of symptomatic os subfibulare with clinical instability of the ankle, a Broström/Gould operation and resection of the os subfibulare is recommended after failure of conservative therapy. Our case showed that a very satisfying post-operative result can be achieved with a modification of the Broström/Gould operation, with reattachment of the ATFL to the talus instead of the fibula.