Sinus tarsi syndrome is a condition characterized by persistent pain and instability in the small cavity or tunnel located on the outside of the ankle between the talus and the calcaneus (heel bone). This area contains several ligaments, nerves, and blood vessels that can become inflamed or damaged.
The pain is typically localized to the small hollow space just in front of the outer ankle bone.
Persistent, deep-seated pain on the lateral (outer) side of the ankle.
A feeling of instability or "giving way" when walking on uneven surfaces or during side-to-side movements.
Tenderness when pressure is applied directly to the opening of the sinus tarsi.
Increased pain when the foot is turned inward (inversion) or outward (eversion).
Morning stiffness in the ankle that improves slightly with movement.
Swelling or a "fullness" sensation in the lateral ankle cavity.
Physical Examination
Diagnostic Injection: Injecting a local anesthetic into the sinus tarsi; if the pain disappears, the diagnosis is confirmed.
MRI: The most effective imaging tool for showing inflammation (edema), ligament tears, or scarring within the sinus tarsi.
CT Scan: Used to identify any bony changes, cysts, or arthritis in the subtalar joint.
X-rays: Usually appear normal but are used to rule out fractures or significant misalignment of the heel bone.
Resting from activities that involve repetitive pivoting or uneven terrain.
Icing the outer ankle for 15 minutes several times a day to manage inflammation.
Non-steroidal anti-inflammatory drugs to reduce deep-seated swelling within the sinus.
Physical therapy to improve proprioception and strengthen the muscles that stabilize the ankle.
Corticosteroid injections into the sinus tarsi can provide relief from chronic inflammation.
Custom orthotics to correct overpronation or oversupination that may be putting mechanical stress on the area.
Activity modification to avoid high-impact jumping or sharp cutting maneuvers.
Surgery to clear out inflamed tissue (debridement) or stabilize the joint if conservative methods fail.