|
|
|
|
|
 What is it? Sinus tarsi syndrome (STS) is a clinical diagnosis characterized with persistent pain over the anterolateral (the outside of the foot underneath the ankle) region of the hind foot known as the sinus tarsi. The cause can be unclear but it is believed that instability of the subtalar joint (foot joint under the ankle) results in joint inflammation and abnormal fibrotic tissue infiltration into the sinus tarsi space. Ankle injuries, such as from recurrent ankle sprains, can cause instability of the subtalar joint, provoking abnormal movement (pronation and supination) through the subtalar joint. The ankle instability can change the normal biomechanics (movement) of the ankle, causing inflammation. Symptoms/Risks The incidence of STS is unclear but is associated with recurrent ankle sprains and trauma. Athletes participating in sports that incorporate jumping, like basketball and volleyball, may be at increased risk of developing an injury to the subtalar joint. Symptoms may include acute or chronic ankle pain with associated swelling and tenderness in the anterolateral ankle. Patients may describe a feeling of ankle instability with running or sprinting. Also, athletes participating in jumping activities may describe a feeling of instability due to excessive pronation and supination of the subtalar joint. However, the development of synovitis and fibrotic tissue infiltration may take time, from which patients with STS may not initially develop pain in the sinus tarsi. Sports Medicine Evaluation & Treatment The sports medicine provider will take a complete medical history, followed by a thorough physical examination that will include evaluation of the joints, tendons, and ligaments around the ankle and foot. The doctor will examine the range of motion of the foot and ankle focusing on the development of pain over the sinus tarsi. He/she will examine the stability of the ankle and foot joints as well Diagnostic studies may include radiographs (x-rays) of the ankle and subtalar joint. Dynamic ultrasound evaluation can be done to evaluate the motions of the subtalar joint with the goal of replicating the movement that causes the patient’s pain. Magnetic resonance imaging (MRI) may be the best diagnostic study to evaluate the different structures around the sinus tarsi. Conservative treatment will incorporate a good rehabilitation program that includes balance training and muscle strengthening exercises. Nonsteroidal anti-inflammatory medications may help control the pain and inflammation. Ice can be administered for 15-20 minutes several times a day to diminish local inflammation. Bracing, taping, and foot orthotics can be considered in addition to shoes that restrict excessive rear foot movements. A diagnostic, and possibly therapeutic, injection of steroids and anesthetic into the sinus tarsi can be an option for pain control. At this time, there is no evidence of the efficacy of regenerative medicine products, like PPR or stem cells, as treatment. Surgical management is only considered on patients who failed conservative treatment. Some athletes may need an arthroscopic exploration and reconstruction of the subtalar joint and surrounding structures in order to return to their sports. Injury Prevention Injury prevention will focus on having adequate training techniques, balance biomechanics, muscle strengthening in the lower extremities, a good stretching program, and shoe wear modifications. Return to Play Return to play is based on the athlete’s ability to perform the necessary movements and skills that are required for their sports. The athlete should progress to functional sports-specific drills during the rehabilitation process before returning to play. The patient’s symptoms should be well-controlled before returning to play, to avoid chronic inflammation of the sinus tarsi structures. AMSSM Member Authors References Category: Foot and Ankle, Trauma, [Back] |
