Sinus Tarsi Syndrome (STS) is characterized by pain and tenderness within the sinus tarsi, a small tunnel-like space located on the outer side of the ankle. This space sits between the talus (ankle bone) and the calcaneus (heel bone), housing ligaments, nerves, and fatty tissue. STS frequently arises from an ankle injury, particularly an inversion sprain where the ankle rolls outward, or from repetitive stress due to activities like standing, walking, or conditions like flat feet. When the tissues within this confined area become inflamed or damaged, it can lead to discomfort and a feeling of instability in the hindfoot.
Non-Surgical Approaches
Initial treatment for Sinus Tarsi Syndrome typically involves conservative methods to reduce pain and inflammation while promoting healing. Rest and activity modification are usually the first steps, requiring individuals to avoid movements that aggravate the foot and ankle, allowing irritated tissues to recover. The RICE protocol—Rest, Ice, Compression, and Elevation—is commonly advised for acute injuries to manage swelling and pain, with ice often recommended for 10-20 minutes multiple times a day.
Physical therapy plays a significant role in rehabilitation, focusing on strengthening muscles around the ankle and improving joint stability. Therapists may guide patients through specific exercises, stretches, and modalities like ultrasound or electrical stimulation to alleviate discomfort. Improving balance and proprioception through exercises like single-leg stands or wobble board training is also incorporated to prevent re-injury.
Supportive devices like orthotics or ankle braces provide mechanical support and help correct biomechanical issues contributing to STS, such as overpronation or flat feet. Orthotics, custom-made or over-the-counter, improve foot and ankle alignment, reducing stress on the subtalar joint. Over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can help manage pain and inflammation.
If conservative measures are insufficient, corticosteroid injections may be considered. These deliver anti-inflammatory medication directly into the sinus tarsi, providing pain relief by reducing inflammation. While effective, injections are not a standalone treatment and are often used to facilitate physical therapy and rehabilitation.
Surgical Considerations
Surgery for Sinus Tarsi Syndrome is a last resort, typically reserved for individuals whose symptoms persist despite prolonged non-surgical treatment, often for six months or more. Its goal is to alleviate chronic pain and instability that conservative methods could not resolve.
Arthroscopic debridement is a common, minimally invasive procedure. A surgeon inserts a small camera and instruments through tiny incisions to visualize the sinus tarsi and remove inflamed tissue, scar tissue, or debris. This technique allows precise removal of problematic tissue, including portions of the interosseous and cervical ligaments, while minimizing disruption.
If arthroscopy is not feasible or for more complex cases, open surgery may be necessary. This involves a larger incision to access the sinus tarsi and address underlying issues like flatfoot deformities or subtalar arthritis. Surgical outcomes can be favorable, with many patients reporting significant improvement in pain and function.
Post-Treatment Recovery and Prevention
Following treatment, a structured rehabilitation program is important for full recovery and to prevent recurrence. This program focuses on restoring the ankle’s full range of motion, strengthening surrounding muscles, and re-establishing proprioception. Gradual return to activity is advised, with physical activity levels slowly increasing to avoid re-injury and allow tissues to adapt. This involves a progressive return to sports or daily activities, listening to the body’s signals to prevent overstressing the healing area.
Appropriate footwear plays a significant role in long-term management and prevention. Supportive shoes with good arch support, cushioned soles, and a stiff heel counter help stabilize the ankle and distribute forces evenly. A podiatrist can offer recommendations and assess wear patterns. Continued use of custom or over-the-counter orthotics may be recommended for ongoing support and to correct underlying biomechanical issues, such as excessive pronation or flat feet, which can contribute to STS recurrence. Addressing these factors reduces stress on the sinus tarsi.
Monitoring symptoms and recognizing signs of recurrence are important. If pain, swelling, or instability return, seeking medical attention promptly allows for early intervention, preventing the condition from becoming chronic or more severe. Consistent adherence to rehabilitation exercises and footwear recommendations contributes to maintaining ankle health and stability.