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Sinus tarsi syndrome

Sinus tarsi syndrome (STS) is a clinical finding that mainly consists of pain and tenderness of the lateral side of the hindfoot, between the ankle and the heel.


STS has been described in dancers, volleyball and basketball players, overweight individuals, and patients with flatfoot and hyperpronation deformities. The incidence of STS is unknown, but it has been associated with ankle sprains that may also result in talocrural joint instability

Clinical presentation

Symptoms include

  • localized pain in the sinus tarsi region.
  • feeling of instability aggravated by weight bearing, especially on uneven surfaces.
  • pain on palpation of the sinus tarsi with aggravation on foot inversion and eversion.
  • cessation of pain on injection of a local anesthetic into the sinus tarsi is diagnostic for STS.



STS probably occurs following one single or a series of ankle sprains that also result in significant injuries to the talocrural interosseous and cervical ligaments. This causes instability of the subtalar joint in supination and pronation movements. In summary, STS can be primarily described as an instability of the subtalar joint due to ligamentous injuries that result in synovitis and scar tissue formation in the sinus tarsi. Haemorrhage or inflammation of the synovial recesses of the sinus tarsi can also cause scarring without tears of the associated ligaments.

Radiographic features

Plain film

Osteoarthritis of the subtalar joint and intraosseous cysts may be present in advanced cases.


Shows secondary bony changes earlier than plain films.

Bone scan - scintigraphy

Inflammatory changes may be attributed to the sinus tarsi / subtalar region.


Probably the best test to show changes in the tissues of the sinus tarsi including inflammation, scar tissue formation or ligamentous injuries.The T1-hyperintense fat in the sinus tarsi space is replaced by either fluid or scar tissue, and the ligaments may be disrupted. Ganglion cysts in the region of the sinus tarsi may compress the posterior tibial nerve.


Conservative treatment is usually effective. It may include anti-inflammatory drugs, stable shoes, a period of immobilization, cryotherapy, ankle sleeve and orthoses. Treatment of ganglion cyts in the sinus tarsi typically consists of surgical excision. Recommendations for rehabilitation include balance and proprioceptive training, and muscle strengthening exercises.


It was first described by Denis O’Connor in 1958

Differential diagnosis

See also

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