M25.579 Pain in unspecified ankle and joints unspecified foot
Sinus Tarsi Syndrome Etiology / Epidemiology / Natural History
Subtalar instability, subtalar joint synovitis and fibrotic tissue infiltration in the sinus tarsi.
"Sinus tarsi syndrome" may be an inaccurate term that should be replaced with a specific diagnosis: interosseous ligament tears, arthrofibrosis, degenerative joint disease (FreyC, Foot Ankle Int 1999;20(3):185-91).
Sinus Tarsi Syndrome Anatomy
Thought to involve injuries to the talocrural interosseous and cervical ligaments.
Interosseous talocalcaneal ligament (ITCL) maintains apposition of the subtalar joint, and has stabilizing effects for the subtalar joint against drawer forces applied to the calcaneus from lateral to medial. Tochigi Y, Foot Ankle Int. 2004 Aug;25(8):588-96
Sinus Tarsi Syndrome Clinical Evaluation
Swelling and tenderness in the anterolateral ankle in the area of the sinus tarsi.
May be associated with pes planus.
Pain over the sinus tarsi at the end range of ankle plantarflexion with foot supination
Sinus Tarsi Syndrome Xray / Diagnositc Tests
Ankle / Foot xrays generally normal; evaluate for pes planus, subtalar arthritis
Magnetic resonance imaging demonstrates subtalar joint chronic synovitis and/or fibrosis
Sinus Tarsi Syndrome Classification / Treatment
Conservative treatment = balance and proprioceptive training, muscle strengthening exercises, bracing, taping, and foot orthosis. Shoes with a straight last, a firm heel counter, and rigid midsole.
Subtalar joint arthroscopy with synovectomy: mean return to full activity was 4 months. The mean postoperative AOFAS Ankle-Hindfoot Scale score = 85 points. (Oloff LM, J Foot Ankle Surg. 2001 May-Jun;40(3):152)
Sinus Tarsi Syndrome Associated Injuries / Differential Diagnosis