Superior peroneal retinaculum reattachment for an atraumatic peroneus brevis tendon subluxation: a case report

BACKGROUND: Peroneal tendon subluxation is a rare pathology, generally associated with sport-induced trauma, that occurs due to the rupture of the superior peroneal retinaculum. The diagnosis is mainly clinical, but the use of imaging techniques, such as dynamic ultrasound and magnetic resonance imaging, may contribute to its clarification. Treatment may be conservative or surgical, although there is no consensus on the most appropriate technique to be employed. We report a case of subluxation of the peroneus brevis tendon, with no apparent traumatic cause, in which there was a need for a surgical approach after the failure of conservative treatment. CASE PRESENTATION: A 25-year-old White woman presented pain and locking of the lateral side of the left foot 2 years earlier, with no history of trauma. The patient felt pain upon palpation and presented snapping during flexion–extension of the left ankle. On dynamic ultrasonography, an anterior subluxation of the peroneus brevis tendon occurred when the ankle was in dorsiflexion, suggesting superior peroneal retinaculum injury. Surgical correction was recommended after 2 months of conservative treatment with no improvement. The chosen surgical technique was isolated reattachment of the superior peroneal retinaculum, which proved successful. CONCLUSIONS: Peroneal tendon subluxation has no established preferred surgical technique. This case demonstrates superior peroneal retinaculum repair as an efficient surgical approach for this condition. Furthermore, the atraumatic mechanism of injury in this case, along with the unknown true incidence of peroneal tendon subluxation, highlights the need to consider this pathology in cases of ankle injuries.