Avulsion fracture of the medial tubercle of the posterior process of the talus

Surgical treatment for posteromedial talar process fractures

PURPOSE

The first descriptions on medial talar tubercle fractures are attributed to Cedell. He described avulsion fractures of the insertion of the posterior talotibial ligament. However the true etiology has not been established. Since little is known about these fractures, they are easily misdiagnosed as simple ankle sprains. Untreated, these fractures may lead to chronic ankle pain. To improve the understanding of the etiology and outcome of these fractures a systematic review was conducted of all cases of isolated fractures of the medial tubercle of the posterior talar process. In addition we present the first series of competitive athletes treated by means of the two-portal hindfoot approach for isolated medial talar tubercle fractures.

METHODS

A systematic search was performed to identify all cases of medial tubercle fractures. Data on trauma mechanism, clinical presentation, imaging and treatment were extracted. In addition we retrospectively report on the results of endoscopically treated patients in our institution over the last fifteen years. Of all patients Numeric Rating Scores (NRS) for Satisfaction, Pain and Function, Foot Ankle Outcome Scores (FAOS), return to sport and complications were reported.

RESULTS

Eightteen articles were included reporting on 33 patients with an isolated fracture or avulsion of the posteromedial talar process. Most of the fractures occurred during sport activities (58%), followed by motor vehicle accidents (21%) and fall from height (12%). Of the activities during sport, 73% resulted following an ankle sprain. Reasonable to good outcomes are described in cases treated with immobilization, open reduction internal fixation or open excision. Of the nine patients treated in our institution, five were male and the median age was 29. All were participating in sports at a competitive level, with four of them being a professional athlete. In most patients the diagnosis was made more than a year after initial trauma. Ankle sprain was most common trauma mechanism. In some patients it was evident the avulsion was part or the deep portion of the deltoid ligament, however in two cases it was more likely an avulsion of the flexor hallucis longus (FHL) retinaculum. The median follow-up was 69 months (IQR 12.0-94.3). At final follow-up patients had little pain, NRS 1. Median NRS for satisfaction and function were 7 and 8, respectively. All patients did resume sport activities, however only four reached the preinjury level. Of the five patients that did not return to their pre-injury level of activity, two were professional athletes at the end of their career, and retired not due to ankle complaints. One complication was reported.

CONCLUSION

Fractures of the medial tubercle are rare and based on the available literature there is not one distinct trauma mechanism. Based on literature no recommendation for treatment can be made. Our results show endoscopic excision of the fragment as a save alternative for open surgical treatment.