An unusual cause of subtalar pain and instability: accessory calcaneus

C Boulet,J De Mey,M De Maeseneer,M Shahabpour,M Kichouh,H Everaert

doi:10.5334/jbr-btr.722

C Boulet, J De Mey + Show 4 more

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https://doi.org/10.5334/jbr-btr.722

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Abstract

We report on a 45-yr-old male sports instructor with chronic pain and instability of the ankle. He was a recreational basketball player, but because of repeated ankle sprains and chronic subtalar pain this activity became impossible. The radiologic findings were compatible with the diagnosis of accessory calcaneus. In an initial therapeutic approach the patient was treated conservatively with taping and physical therapy, but this failed to relieve the symptoms. Next, a ligamentoplasty was performed. The instability improved, but the pain remained the same. Finally the accessory calcaneus was resected and short term follow-up was unremarkable. Accessory calcaneus is an uncommon anatomical variation that may cause subtalar pain and instability. Resection of the accessory bone may be necessary to provide relief of symptoms. Accessory calcaneus can be well demonstrated on CT, SPECT-CT, and MR. MR and nuclear medicine can indicate instability of the accessory bone by showing bone marrow edema on MR or uptake on fusion imaging.

Highlights

We report on a 45-yr-old male sports instructor with chronic pain and instability of the ankle
To the best of our our knowledge only a few case reports have been published [2,3,4,5,6,7,8,9]. This anatomic variant should not be confused with an os calcaneum secundarium, which corresponds to a small ossicle located at the level of the anterior process of the calcaneus.This other variant may be confused with an avulsion fracture
Instability of the accessory os calcaneum may lead to bone marrow edema pattern on MR, or uptake on nuclear medicine studies

Summary

Introduction

We report on a 45-yr-old male sports instructor with chronic pain and instability of the ankle. Sesamoid bones and accessory ossicles about the foot and ankle are relatively common and represent developmental variants [1, 2]. Instability of the accessory os calcaneum may lead to bone marrow edema pattern on MR, or uptake on nuclear medicine studies. A 45-year-old male sports instructor was seen at the orthopaedic clinic because of instability and pain along the lateral aspect of the ankle. Note the corticalized accessory bone at the level of the sinus tarsi (arrow).

Results

Conclusion