Medically Reviewed by Dr. Jeffery Agnoli, DPM — Board-Certified Podiatrist, Balance Foot & Ankle Specialists, Michigan. Last updated April 2026.
Tarsal coalition — an abnormal bridge of bone, cartilage, or fibrous tissue connecting two tarsal bones — is a congenital condition that produces progressive hindfoot and midfoot stiffness in adolescence as the coalition matures and ossifies. The two most common coalitions — calcaneonavicular (CN) and talocalcaneal (TC, specifically at the middle facet of the subtalar joint) — together account for 90% of all tarsal coalitions and present with a distinctive clinical pattern of activity-related hindfoot pain and rigidity in teenagers.
Clinical Presentation and Diagnosis
Typical presentation: a 10–15 year old presenting with hindfoot or midfoot pain that worsens with prolonged standing and athletic activity; bilateral in 50–60% of cases; associated flatfoot deformity; peroneal spasm (‘peroneal spastic flatfoot’) — involuntary spasm of the peroneal muscles producing a valgus hindfoot posture that resists manual correction. Physical examination: restricted subtalar inversion-eversion (the hallmark finding); pain with subtalar range of motion; the ‘too many toes’ sign on standing. Imaging: CN coalition: lateral X-ray shows the ‘anteater sign’ — elongation of the anterior calcaneal process extending toward the navicular; oblique X-ray shows the coalition directly. TC coalition: Harris (axial) heel view shows narrowing or sclerosis of the middle facet; CT scan is the definitive diagnostic test for TC coalition — shows the bone bridge, its extent, and any secondary degenerative changes. MRI: identifies fibrocartilaginous (non-osseous) coalitions that are invisible on CT.
Treatment
Conservative management: orthotics with motion control to reduce subtalar motion; activity modification; immobilization in a cast or boot for acute flare; cortisone injection at the coalition site. Surgical resection: CN coalition resection — direct excision of the coalition with interposition of the extensor digitorum brevis muscle to prevent re-ossification; 85–90% success rate for pain relief; appropriate when <50% of subtalar joint is arthritic. TC coalition resection: excision of the middle facet coalition via medial approach; results less predictable than CN resection; appropriate for coalitions <50% of the middle facet. Subtalar fusion: for coalitions with secondary subtalar arthritis, failed resection, or large coalition size — sacrifices motion in exchange for pain relief. Dr. Biernacki at Balance Foot & Ankle evaluates pediatric and adolescent hindfoot stiffness with X-ray and CT to identify and manage tarsal coalition. Call (810) 206-1402 at our Bloomfield Hills or Howell office.
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Frequently Asked Questions
When should I see a podiatrist?
See a podiatrist for any foot or ankle pain that persists more than 2 weeks, doesn’t improve with rest, limits your daily activities, or is accompanied by swelling, numbness, or skin changes. People with diabetes or circulation problems should see a podiatrist regularly even without symptoms.
What does a podiatrist treat?
Podiatrists diagnose and treat all conditions of the foot, ankle, and lower leg including plantar fasciitis, bunions, hammertoes, toenail problems, heel pain, nerve pain, diabetic foot care, sports injuries, fractures, and foot deformities — both surgically and non-surgically.
What can I expect at my first podiatry visit?
Your first visit includes a full medical history, physical examination of your feet and gait, and in-office diagnostic imaging if needed (X-rays, ultrasound). We’ll discuss your diagnosis and create a personalized treatment plan. Most visits take 30–45 minutes.
Need Treatment at Balance Foot & Ankle?
Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin see patients at our Howell and Bloomfield Township offices.
Book Online or call (810) 206-1402
Dr. Tom Biernacki, DPM is a double board-certified podiatrist and foot & ankle surgeon at Balance Foot & Ankle Specialists in Southeast Michigan. With over a decade of clinical experience, he specializes in heel pain, bunions, diabetic foot care, sports injuries, and minimally invasive surgery. Dr. Biernacki is a member of the APMA and ACFAS, and his patient education content on MichiganFootDoctors.com and YouTube has reached over one million views.