One time while I was still giving piano lessons at a local high school, one of my students complained about having a sprained foot. It was later discovered that he had sinus tarsi syndrome or STS. I just remembered that student now because one of my friends cancelled our appointment because of the same reason. That stirred my curiosity about this syndrome.
STS is a condition that causes persistent tenderness and pain in the sinus tarsi region due to inflammation. The sinus tarsi region is a small cavity located outside the hind foot, in between the heel bone and the talus. If treated immediately, quick recovery can be expected; otherwise, it can lead to severe and chronic pain.
There are several factors that can cause STS. One common factor is when a person experiences a sprained ankle or strain from regular walking or running on flat foot. Sprain causes instability and excessive movement of the sinus tarsi area leading to inflammation and formation of scar tissue. STS can develop after a single sprain or repeated sprains. Additionally, people with flat feet or over-pronated feet are also prone to STS. That is because these abnormal foot biometrics cause more pressure in the sinus tarsi area. Ballet and sitting down with tucked feet underneath are also among the reasons why a person may develop STS.
The best way to diagnose STS is through an MRI scan. Some doctors may also inject corticosteroids and local anesthetic in the sinus tarsi region. If the symptoms cease, it indicates that a person has STS. The temporary relief from the injection is normally short-lived and further treatment is needed. However, if the symptoms remain after the injection, it indicates another problem and is not STS.
If there is a positive diagnosis for STS at an early stage, full recovery can be accomplished in just a couple of weeks. But if the problem is not treated early on, the pain could linger for many months.
Here are some ways on how to care and treat STS:
- Rest – rest is essential for STS patients. Any activities that involve leg movement might trigger the pain and must be avoided. You may also have to use an ankle brace or crutches for a short time. Most patients normally experience prolonged pain because they are unable to rest and avoid aggravating activities.
- NSAIDs – your doctor may also prescribe NSADs to reduce inflammation and pain.
- Ice – You can temporarily alleviate the pain by massaging ice on the affected area for several minutes.
- Others – other treatments include physiotherapy, joint mobilizations, exercises that can strengthen the sinus tarsi, and wearing of supportive footwear. In rare instances, surgery might also be necessary if the symptoms still persist despite trying all other procedures and treatment. Surgery may involve the removal of chronic synovitis or inflammation as well as the scar tissues. The ligaments in the subtalar joint may also need to be reconstructed.
STS may bring discomfort and too much pain on a patient. In some instances, it can prevent the person from doing his normal activities. But by early detection and treatment, this condition will settle down in less than a month.