Tarsal Tunnel Syndrome Following Medializing Calcaneal Osteotomy

CATEGORY: Hindfoot INTRODUCTION/PURPOSE: The tarsal tunnel syndrome is a compressive neuropathy that affects either the posterior tibial nerve, within the tarsal tunnel, or one of its terminal branches. It can be caused by extrinsic or intrinsic factors. Even though the tarsal tunnel syndrome has been reported as a complication of lateralizing calcaneal osteotomy, we have not identified in the literature reports of this syndrome associated to medializing calcaneal osteotomy. We report the case of a 60-year-old female who developed a tarsal tunnel syndrome, on the third postoperative week, following a medializing calcaneal osteotomy for flatfoot correction with stage IIB posterior tibial tendon dysfunction. METHODS: We reviewed and obtained the information from the medical records of this patient: clinical examination, radiographs, computed tomography, magnetic resonance imaging, and outcome. Pain was assessed with visual analog scale (VAS). RESULTS: The patient is a 60-year-old female with left stage II posterior tibial tendon dysfunction who failed to respond to conservative treatment. Medializing and lengthening (Evans) osteotomies of the calcaneus were performed, together with posterior tibial tendon repair and spring ligament reconstruction. In the postoperative, after a cast replacement into a more plantigrade position, the patient developed symptoms that suggested a compressive neuropathy of posterior tibial nerve within the tarsal tunnel associated to calcaneal medializing osteotomy. Initial conservative treatment failed and the posterior tibial nerve was explored under loupe magnification and the tarsal tunnel was released. Figure 1. An immediate improvement in pain was observed postoperatively and almost full recovery occurred within 6 months. CONCLUSION: In our case report, the tarsal tunnel syndrome was a consequence of the osteotomy fragment displacement that generated a reduction of the tarsal tunnel volume. It has been described that the tarsal tunnel syndrome symptoms become more evident with ankle dorsiflexion and eversion, in our patient this can be associated with the symptom exacerbation presented when the cast was placed into plantigrade position. We conclude that even though in the literature the tarsal tunnel syndrome has been mainly associated to lateralizing osteotomies, it is important to take this complication into account when performing a medializing osteotomy.