Tarsal tunnel syndrome caused by an uncommon ossicle of the talus

Abstract

Rationale:Tarsal tunnel syndrome (TTS) is a compressive neuropathy of the posterior tibial nerve or one of its branches within the tarsal tunnel that is often caused by a variety of space-occupying lesions, such as ganglia, lipomas, varicosities, neural tumors, trauma, or systemic disease. The os sustentaculi is a small accessory bone, bridged to the posterior aspect of the sustentaculum tali by fibrocartilage. To the best of our knowledge, this is a rare case of successful treatment of TTS caused by the os sustantaculi.Patient concerns:A 37-year-old male presented with insidious onset of right ankle and foot pain for 1 year. He also complained of a tingling sensation and paresthesia from the plantar and medial aspect of the forefoot to the middle foot area along the main distribution of the medial plantar nerve. The symptoms were mild at rest, but increased upon prolonged walking. He had an ankle sprain history during a football game 2 years previously and recurrent ankle sprains had occurred more frequently in this ankle since that trauma.Diagnoses:Plain standing anteroposterior and lateral view radiographic findings of the right ankle reveled an accessory ossicle located posterosuperomedial to the sustentaculum tali. A computed tomography scan showed that the ossicle articulated between the talus and calcaneus. A magnetic resonance image revealed mild bone marrow edema in the ossicle and medial displacement of the tarsal structures.Interventions:Surgery was performed under general anesthesia. The ossicle was delineated from its surrounding structures and was removed. Tension on the nerve was released.Outcomes:The patient's pain and hypoesthesia were immediately relieved, and the tingling sensation disappeared 6 months after surgery. The patient had no complications or recurrence of symptoms at the 1-year follow-up.

Vascular entrapment neuropathy of the tibial nerve within the gastrocnemius muscle

“…Tibial neuropathies, in particular, are typically heavily attributed to both impingement and/or injury such as with tarsal tunnel syndrome and entrapment deep to the flexor retinaculum. [2,4] is same phenomenon could be caused by any other source of impingement such as space-occupying lesions, compartment syndromes, or other morphologic variants. [2,7] For instance, in a 2013 study by Tang et al, they evaluated the effects of acute compartment syndrome and subsequent proximal tibial nerve compression by the soleus tendinous arch.…”

A case of osteophyte excision and arthroscopic arthrodesis for tarsal tunnel syndrome with traumatic osteoarthritis of the ankle

“…Regarding TTS entrapment/impingement from bony factors, Bejjanki et al reported on a case of TTS following ankle replacement surgery secondary to a large displaced osteophyte [ 7 ]. Hong also reported on a case of successful treatment of TTS caused by os sustentaculum [ 9 ]. However, to our knowledge, there is the first report of TTS with osteophyte due to traumatic osteoarthritis of the ankle treated with osteophyte excision and arthroscopic arthrodesis.…”

Tarsal Tunnel Syndrome: An Ultrasound Pictorial Review

“…An os trigonum may lead to flexor hallucis longus tenosynovitis that can affect the tibial nerve. An os sustentaculi is a large accessory ossicle that projects to the sustentaculum tali and can squeeze the posterior tibial nerve or one of its branches 5,7,8 . Ossifications within the tarsal tunnel, which also represent an uncommon cause of TTS, appear on ultrasound as a hyperechoic line or dots with acoustic shadowing (Figure 6).…”

“…The widely used Tinel test also has low specificity due to high intra‐examiner and inter‐examiner variability, resulting in poor specificity 1 . Plain X‐rays are helpful to exclude bone abnormalities 5 …”