Tarsal tunnel syndrome secondary to osteochondroma of the calcaneus: a case report

An update on imaging of tarsal tunnel syndrome

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve (TN) within the tarsal tunnel (TT) at the level of the tibio-talar and/or talo-calcaneal joints. Making a diagnosis of TTS can be challenging, especially when symptoms overlap with other conditions and electrophysiological studies lack specificity. Imaging, in particular MRI, can help identify causative factors in individuals with suspected TTS and help aid surgical management. In this article, we review the anatomy of the TT, the diagnosis of TTS, aetiological factors implicated in TTS and imaging findings, with an emphasis on MRI.

Tarsal tunnel syndrome: current rationale, indications and results

Tarsal tunnel syndrome (TTS) is a neuropathy due to compression of the posterior tibial nerve and its branches. It is usually underdiagnosed and its aetiology is very diverse. In 20% of cases it is idiopathic. There is no test that diagnoses it with certainty. The diagnosis is usually made by correlating clinical history, imaging tests, nerve conduction studies (NCSs) and electromyography (EMG). A differential diagnosis should be made with plantar fasciitis, lumbosacral radiculopathy (especially S1 radiculopathy), rheumatologic diseases, metatarsal stress fractures and Morton’s neuroma. Conservative management usually gives good results. It includes activity modification, administration of pain relief drugs, physical and rehabilitation medicine, and corticosteroid injections into the tarsal tunnel (to reduce oedema). Abnormally slow nerve conduction through the posterior tibial nerve usually predicts failure of conservative treatment. Indications for surgical treatment are failure of conservative treatment and clear identification of the cause of the entrapment. In these circumstances, the results are usually satisfactory. Surgical success rates vary from 44% to 96%. Surgical treatment involves releasing the flexor retinaculum from its proximal attachment near the medial malleolus down to the sustentaculum tali. Ultrasound-guided tarsal tunnel release is possible. A positive Tinel’s sign before surgery is a strong predictor of surgical relief after decompression. Surgical treatment achieves the best results in young patients, those with a clear aetiology, a positive Tinel’s sign prior to surgery, a short history of symptoms, an early diagnosis and no previous ankle pathology.

Cite this article: EFORT Open Rev 2021;6:1140-1147. DOI: 10.1302/2058-5241.6.210031

Solitary Osteochondromas of the Metatarsal and Cuneiform, in an Adolescent

Introduction

Solitary osteochondromas are extremely rare in the bones of the foot. In the growing skeleton, few cases affecting the metatarsals and the talus have been reported. At present, there have been no reports of osteochondromas affecting the cuneiforms.

Case Report

We report the case of a 13-year-old male patient. He presented with marked prominences in the plantar surface of his left foot and pain while participating in sporting activities. Radiological examination with X-rays, computed tomography (CT) scan, and magnetic resonance imaging revealed two solitary osteochondromas growing from the medial cuneiform and the head of the 1st metatarsal. The patient was treated surgically by excision of the osteochondromas. Histological examination confirmed the diagnosis of osteochondromas. He had an uneventful recovery and returned to his sporting activities.

Conclusion

Solitary osteochondroma can present in the cuneiform and metatarsal of a growing adolescent. CT scan is useful for the accurate diagnosis and surgical removal of the tumor.