Tarsal tunnel syndrome: a still challenge condition / Síndrome do túnel do tarso: uma condição ainda desafiadora

Tarsal tunnel syndrome is a rare, under diagnosed and often confused neuropathy with other clinical entities. There is a lack of population studies on this disease. Herein, we performed a non-systematic review of articles between January 1992 and February 2018. Although with a less complex anatomy comparing to the carpal tunnel, the tarsal tunnel is source of pain and some other conditions. Treatment involves conservative measures such as analgesics and physical therapy rehabilitation or surgical procedures in case of conservative treatment failure. Randomized control studies are lack and mandatory for uncover the best modality of treatment for this condition.

A Síndrome do túnel do tarso é uma rara e subdiagnosticada neuropatia geralmente confundida com outras entidades clínicas. Há falta de estudos populacionais sobre a doença. Assim sendo, realizamos uma revisão da literatura de artigos entre Janeiro de 1992 e fevereiro de 2018. Apesar de possuir uma anatomia de menor complexidade comparada ao túnel do carpo, o túnel do tarso é origem de dor e algumas outras condições. O tratamento envolve medidas conservadoras como analgésicos e terapia de reabilitação ou procedimentos cirúrgicos, em caso de falha do tratamento conservador. Estudos randomizados são escassos e necessários para descoberta da melhor modalidade de tratamento desta condição.

Neurovascular Compression Caused by Popliteus Muscle Enlargement Without Discrete Trauma

Popliteal entrapment syndrome caused by isolated popliteus muscle enlargement is very rare, although its occurrence has been reported after discrete trauma. However, popliteal artery stenosis with combined peroneal and proximal tibial neuropathy caused by popliteus muscle enlargement without preceding trauma has not been reported. A 57-year-old man presented with a tingling sensation and pain in his left calf. He had no previous history of an injury. The symptoms were similar to those of lumbosacral radiculopathy. Calf pain became worse despite treatment, and the inability to flex his toes progressed. Computed tomography angiography and magnetic resonance imaging of the lower extremity showed popliteal artery stenosis caused by popliteus muscle enlargement and surrounding edema. An electrodiagnostic study confirmed combined peroneal and proximal tibial neuropathy at the popliteal fossa. Urgent surgical decompression was performed because of the progressive neurologic deficit and increasing neuropathic pain. The calf pain disappeared immediately after surgery, and he was discharged after the neurologic functions improved.

Neurovascular Compression Caused by Popliteus Muscle Enlargement Without Discrete Trauma

Popliteal entrapment syndrome caused by isolated popliteus muscle enlargement is very rare, although its occurrence has been reported after discrete trauma. However, popliteal artery stenosis with combined peroneal and proximal tibial neuropathy caused by popliteus muscle enlargement without preceding trauma has not been reported. A 57-year-old man presented with a tingling sensation and pain in his left calf. He had no previous history of an injury. The symptoms were similar to those of lumbosacral radiculopathy. Calf pain became worse despite treatment, and the inability to flex his toes progressed. Computed tomography angiography and magnetic resonance imaging of the lower extremity showed popliteal artery stenosis caused by popliteus muscle enlargement and surrounding edema. An electrodiagnostic study confirmed combined peroneal and proximal tibial neuropathy at the popliteal fossa. Urgent surgical decompression was performed because of the progressive neurologic deficit and increasing neuropathic pain. The calf pain disappeared immediately after surgery, and he was discharged after the neurologic functions improved.

Compressive Neuropathy of the Posterior Tibial Nerve at the Lower Calf Caused by a Ruptured Intramuscular Baker Cyst

Baker cyst is an enlargement of the gastrocnemius-semimembranosus bursa. Neuropathy can occur due to either direct compression from the cyst itself or indirectly after cyst rupture. We report a unique case of a 49-year-old man with left sole pain and paresthesia who was diagnosed with posterior tibial neuropathy at the lower calf area, which was found to be caused by a ruptured Baker cyst. The patient's symptoms resembled those of lumbosacral radiculopathy and tarsal tunnel syndrome. Posterior tibial neuropathy from direct pressure of ruptured Baker cyst at the calf level has not been previously reported. Ruptured Baker cyst with resultant compression of the posterior tibial nerve at the lower leg should be included in the differential diagnosis of patients who complain of calf and sole pain. Electrodiagnostic examination and imaging studies such as ultrasonography or magnetic resonance imaging should be considered in the differential diagnosis of isolated paresthesia of the lower leg.

Compressive Tibial Neuropathy Induced by Myxoid Liposarcoma in the Popliteal Fossa

Tibial nerve compression occurs most often at the ankle. A proximal tibial nerve entrapment at the popliteal fossais rare because of the deep location of the nerve. We report a case of tibial neuropathy caused by a myxoid liposarcoma at the popliteal fossa, which was diagnosed by electrophysiologic studies, magnetic resonance imaging and an open excisional biopsy. This case illustrates that tumors should be considered when patients present with an entrapment neuropathy of the proximal tibial nerve.

Posterior tibial neuropathy by a Baker's cyst

Baker's cysts are rare cause of peripheral nerve entrapment and only a few cases of tibial nerve entrapment resulting from the popliteal cyst in the calf muscle have been reported in the literature. We present a case of rheumatoid arthritis complicated by a Baker's cyst with a tibial nerve entrapment. It is important to diagnose a Baker's cyst early and to differentiate it from thrombophlebitis, a popliteal aneurysm, tumor or muscle tear to effect optimal therapy and to obviate a potential neuropathy. Prompt recognition of these cases may save the patients unnecessary procedures and delay in treatment.