Tarsal Coalition
synonyms: Calcaneonavicular coalition, talocalcaneal coalition, peroneal spastic flatfoot
Tarsal Coalition ICD-9
- 755.67 (Anomalies of foot, NEC) tarsal coalitions, talonavicular synostosis, coalition of calcaneous, calcaneonavicular bar, astrgaloscaphoid synostosis)
Tarsal Coalition Etiology / Epidemiology / Natural History
- Congenital anomaly with the union of 2 or more tarsal bones causing decreased or absent motion.
- can be a cartilaginous, fibrous, or bony union most often seen in the hindfoot and less commonly in the midfoot.
- typically teenager with increasingly midfoot pain, insidious onset, activity related, and relieved by rest. Stiffness of foot, hx of ankle sprains.
- Disorder of mesenchymal segmantation. May be inherited in an autosomal dominant pattern. (Leonard MA: JBJS 1974;56Br:520-526)
- Occurs in @1% of US population
- 50-60% bilateral
- talocalcaneal, calcaneonavicular most common. Rare=talonavicular, calcaneocuboid, cubitonavicular, and naviculocuneiform joints.
- leading cause of peroneal spastic flatfoot
Tarsal Coalition Anatomy
Tarsal Coalition Clinical Evaluation
- history of repeated ankle sprains or vague, nonspecific symptoms in the hindfoot or midfoot following minor trauma.
- c/o calf pain due to peroneal spasticity, flatfoot, limited subtalar motion,
- Typically teenagers, age 10-12
- restriction of hindfoot inversion and eversion, full ROM of ankle
Tarsal Coalition Xray / Diagnositc Tests
- plain radiographs often normal, best evaluated with CT scan(Herzenberg, Foot Ankle 1986;6:273-288)
- C-sign on lateral x-ray is highly sensitive and specific for TCC. C-sign = a C-shaped line formed by the medial outline of the dome of the talus and the posteroinferior outline of the sustentaculum tali. (Sakellariou A et al: Talocalcaneal coalition: Diagnosis with the C sign on lateral radiographs of the ankle. JBJS Br 2000;82:574-578)
- Other x-ray findings include a talar beak, narrowing of the posterior subtalar joint space, failure to visualize the middle subtalar joint, and loss of height of the longitudinal arch.
- CT: indicated before surgical treatment to ipsilateral coalitions, ie concommitant calcaneonavicular and subtalar coalitions.
Tarsal Coalition Classification / Treatment
- conservative=heel cup with medial-wedge or longitudinal arch support. Short leg walking cast with slight varus mold for 2-4weeks followed by UCBL orthosis.
- Calcaneonavicular or talocalcaneal coalition=WBSLC for 2-4wks followed by UCBL orthosis. Consider resection of the coalition and interposition of autogenous fat graft, or extensor digitorum brevis muscle if non-op treatment fails (Gonzalez P, JBJS 1990;72A:71).
- Consider primary triple arthrodesis in patients with degenerative changes in the subtalar or midfoot joints.
Tarsal Coalition Associated Injuries / Differential Diagnosis
- Fibular hemimelia
- Proximal focal femoral deficiency
- Phocomelia
- Hypoplastic femur
- Symphalagism
- Carpal Coalitions
- Apert syndrome
- Nievergelt-Pearlman syndrome
Tarsal Coalition Complications
Tarsal Coalition Follow-up Care
Tarsal Coalition Review References
- Kulik SA Jr, Clanton TO: Tarsal coalition. Foot Ankle Int 1996;17:286-296.
- Vincent KA, JAAOS, 1998;6:274
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