Tarsal tunnel syndrome is similar to a carpal tunnel syndrome in the wrist area. In other words, it is a nerve entrapment compression.
The posterior tibial nerve (thanks to www.aafp.org for the image) passes through the tarsal tunnel, which is a tunnel-like structure below the medial ankle. It can be compressed due to various reasons and cause pain on the inside of the ankle (thanks to www.footeducation.com for the images). Various conditions could bring this on such as abnormal foot motions, arthritis of the ankle, flexor tendinitis or venous insufficiency with associated swelling (edema).
Ankle pain gets worse with walking and standing, and radiates into the toes. There is worsening of the pain with tapping below the medial ankle (called “Tinel sign“; thanks to www.yourmedicaldetective.com for the link). Electromyography shows exactly where the blockage is located and this needs to be done before surgery would be contemplated. If nerve entrapment is proven by EMG studies, no time should be wasted to have a surgeon do a surgical release, so that the nerve does not get damaged permanently through nerve atrophy. This surgery is called tarsal tunnel release.
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