Tarsal tunnel syndrome is a condition caused by compression of the tibial nerve and its branches in the inner ankle, which leads to tingling, burning, shooting pain, pins and needles, and other symptoms common to nerve issues.
The tibial nerve is the main nerve that supplies muscle function and sensation to the entire bottom of your foot and heel. This nerve (with its branches) passes through a series of tunnels made of fascia and connective tissue as it travels from the back of the ankle into the arch of the foot and down to toes. This is much like the nerve passing through the carpal tunnel in the wrist.
Like carpal tunnel syndrome, tarsal tunnel syndrome is often a result of trauma caused by repetitive motion or overuse of the ankle. It can also happen in conjunction with an ankle sprain, ankle fracture, cyst, flat feet, or overpronation. You might also have to seek tarsal tunnel treatment because of obesity, diabetes, ankle arthritis, pregnancy or hypothyroidism.
Surgery is typically the answer for patients who have not benefited from conservative treatments, like physical therapy, injections, or orthotic devices, and have symptoms that significantly affect their daily lives. As such, you expect a surgical procedure to address the problem. So you may be wondering “why does my foot still hurt after ‘tarsal tunnel surgery?’”
That is an excellent question and it’s a very complicated answer. There are several reasons why you may continue to have symptoms consistent with tarsal tunnel syndrome after a previous tarsal tunnel release. We would like to highlight a few of those reasons:
- Incomplete release. By far and away the most common reason we see patients with failed tarsal tunnel procedures performed elsewhere is incomplete release. This is one of the biggest reasons for failed tarsal tunnel procedures, and it’s one we may be able to fix for you. The problem in this case is that your initial surgeon may have released the tibial nerve, but not the three branches downstream. Dr. Lee Dellon, Dr. William’s partner, spent many years proving that TTS does not only cause compression of tibial nerve but also branches downstream. (By the way, Dr. Williams has spent ten years working with him.) There are many cases where releasing those other branches leads to relief from pain and other symptoms.
- Scar tissue. The second-most common problem we see is buildup of scar tissue. It’s entirely possible that your surgeon performed the procedure correctly and was able to properly release all four affected nerves (the tibial nerve and its medial plantar, lateral plantar, and calcaneal branches).
The issue in this case is that scar tissue develops following the procedure due to bleeding or prolonged immobilization after surgery. Unfortunately, some patients have genetic propensity to lay down thicker scar tissue.
To remedy this, we may recommend reopening the surgical site, removing scar tissue, and making sure patient is moving the ankle as soon as possible. We often have them walking within 48 hours and never use a completely restrictive boot (so the nerve can glide after scar tissue has been released). We prevent issues with early mobilization and weight-bearing.
You can think of this like steel-reinforced concrete. You put the steel rebar in the cement and then let it harden. This is like putting a boot on you. The nerve is trapped and unable to glide as naturally intended. If you had a machine, though, that kept moving the steel while the concrete cured, there would be a hole wherein the rebar can pass through without getting stuck.
- Injured nerves caught in the incision. Some patients may find relief in sole of foot, but now complain of pain in surgical scar itself. This can make it difficult to wear socks or shoes and there is hypersentiivty in the scar. The problem may be caused by injury to a very small nerve to the skin (in the region of the scar). A simple injection can help prove this. If that is the case, the nerve—which is small (about the size of a small clump of hair) and unnecessary—can be removed to improve comfort of surgical scar and take the pain away. Hard to believe such a small nerve can cause such a big problem, but it happens.
- You don’t have tarsal tunnel syndrome. It’s certainly possible that the condition causing the pain in your foot isn’t this one. If this is the case, releasing the tibial nerve won’t solve the problem for you. Ideally, this must be kept in mind and carefully searched for prior to embarking on tarsal tunnel release. If the patient doesn’t recover after surgery, the index of suspicion rises.
- Pinched nerves upstream. This is another instance wherein the procedure to release the tibial nerve—and perhaps even the three branches downstream—at the ankle was performed correctly, but symptoms weren’t resolved. In this case, though, the problem might actually be above the tarsal tunnel and in the calf where the tibial nerve may be pinched as it travels behind knee.
There could be pressure on the nerve before it passes down along the back of the foot and down into the foot. Dr. Williams has published several papers about this potential entrapment site, and it is far more frequent than appreciated. This tibial nerve compression in the calf behind the knee presents almost identically to tarsal tunnel syndrome and can be easily misdiagnosed.
- Medical peripheral neuropathy. The problem causing pain in sole of foot may be degeneration of nerve due to factors other than compression. These can include Lyme disease, diabetes, heavy metal toxicity, small fiber peripheral neuropathy, and a whole host of other medical neuropathies.
As you can see this is a complex issue. We know it is frustrating to have surgery to fix a problem, and then still experience pain afterwards. Fortunately, we may be able to help. At the very least, we would be happy to provide a second opinion.
For additional information, or to request a consultation with our Baltimore office, simply call (410) 709-3868 and one of our team members will be glad to help.