Tarsal Coalition: Calcaneonavicular vs. Talocalcaneal, Rigid Flatfoot in Adolescents

Medically reviewed by Dr. Tom Biernacki, DPM — Board-Certified Podiatric Surgeon — Balance Foot & Ankle, Howell & Bloomfield Hills, MI. Last updated April 2026.

Tarsal coalition — an abnormal bony, cartilaginous, or fibrous bridge between two tarsal bones — is the most common structural cause of rigid, painful flatfoot in adolescents, typically becoming symptomatic between ages 8–16 when ossification of the coalition bridge increases rigidity. The two most common coalition types are calcaneonavicular (CN) coalition (comprising 53% of cases) and middle facet talocalcaneal (TC) coalition (37% of cases) — each with distinct radiographic characteristics, clinical presentations, and surgical approaches.

Clinical Presentation and Diagnosis

Characteristic presentation: adolescent with painful flatfoot, stiff hindfoot that does not correct on single-leg heel rise (rigid valgus heel), peroneal muscle spasm (“peroneal spastic flatfoot” — the peroneal muscles contract to stabilize the coalited subtalar joint), and pain with walking on uneven terrain. CN coalition is best visualized on the oblique plain X-ray view — the “anteater sign” (elongated anterior calcaneal process extending toward the navicular). TC coalition (middle facet) requires CT imaging for definitive diagnosis — the standard X-ray may show the “C sign” (continuous C-shaped bone outline at the talar sustentaculum and posterior talus) but CT provides precise visualization of the coalition size and joint involvement critical for surgical planning.

Conservative and Surgical Management

Conservative management: immobilization in a short-leg cast or CAM boot for 4–6 weeks to reduce inflammation and pain, followed by custom orthotics providing hindfoot support and accommodating the limited subtalar motion. Surgical management: coalition resection — the bridge is excised and the space is interposed with fat graft (CN coalition) or extensor digitorum brevis muscle (CN coalition) to prevent re-ossification. Resection produces excellent outcomes when the coalition involves less than 50% of the posterior subtalar facet (TC coalition) — larger coalitions with secondary subtalar arthritis are treated with subtalar arthrodesis. Concurrent calcaneal osteotomy for hindfoot valgus correction improves outcomes for complex cases. Dr. Biernacki at Balance Foot & Ankle evaluates adolescent and adult rigid flatfoot with standing X-rays and CT when coalition is suspected. Call (810) 206-1402 at our Bloomfield Hills or Howell office.

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In-Office Treatment at Balance Foot & Ankle

If home care isn’t resolving your your foot or ankle concern, a visit with a board-certified podiatrist is the fastest path to accurate diagnosis and a personalized plan. At Balance Foot & Ankle Specialists, Dr. Tom Biernacki, Dr. Carl Jay, and Dr. Daria Gutkin offer same-day and next-day appointments at both our Howell and Bloomfield Hills offices. We perform on-site diagnostic ultrasound, digital X-ray, conservative care, advanced regenerative treatments, and minimally invasive surgery when indicated.

Call (810) 206-1402 or request an appointment online. Most insurance plans accepted, including Medicare, Blue Cross Blue Shield, Aetna, Cigna, and United Healthcare.

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 plan tailored to your foot type. 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 Hills offices.

Book Online or call (810) 206-1402

Differential Diagnosis: What Else Could It Be?

Several conditions share symptoms with Flat Feet (Pes Planus) and are commonly misdiagnosed in the first office visit. Considering these alternatives is part of every Balance Foot & Ankle exam:

• Posterior tibial tendon dysfunction (PTTD). Acquired adult flatfoot with single-leg heel-rise weakness.
• Tarsal coalition. Rigid flatfoot in an adolescent — bone bridge between hindfoot bones.
• Charcot foot (diabetic). Sudden warm, swollen, collapsing midfoot in a diabetic — urgent off-loading.

If your symptoms don’t fit the textbook pattern, ask your podiatrist which differentials they ruled out — that conversation often shortcuts months of trial-and-error treatment.

Most Common Mistake We See

The most common mistake we see is: Buying motion-control shoes without a gait assessment. Fix: get a pressure-plate analysis or wet-foot test first to confirm overpronation and arch height.

Warning Signs That Need Same-Day Care

Frequently Asked Questions

When should I see a podiatrist?

If symptoms persist past 2 weeks, affect your normal activity, or are accompanied by red-flag symptoms (warmth, redness, swelling, inability to bear weight).

What does treatment cost?

Most diagnostic visits and conservative treatments are covered by Medicare and major insurers. Out-of-pocket costs vary by your specific plan.

How quickly can I get an appointment?

Most non-urgent cases see us within 5 business days. Urgent cases (sudden pain, possible fracture) typically same or next business day.

What is Foot pain?

Foot pain is a common foot/ankle condition that affects mobility and quality of life. Understanding the underlying cause is the first step in successful treatment. Our podiatrists at Balance Foot & Ankle perform a hands-on biomechanical exam, review your activity history, and use diagnostic imaging when appropriate to identify the root cause—not just treat the symptom. Many patients have been told to “rest and ice” without a deeper diagnostic workup; our approach is different.

Symptoms and warning signs

Common signs of foot pain include pain that worsens with activity, morning stiffness, swelling, tenderness when palpated, and difficulty bearing weight. If you experience sudden severe pain, inability to walk, visible deformity, numbness or color change, contact our office the same day or visit urgent care—these can signal a more serious injury such as a fracture, tendon rupture, or vascular compromise. Diabetics with any foot wound should seek same-day care.

Conservative treatment options

Most cases of foot pain respond to non-surgical care: structured rest, supportive footwear changes, custom orthotics, targeted stretching and strengthening protocols, anti-inflammatory medications when medically appropriate, and in-office procedures such as ultrasound-guided injections. We also offer advanced therapies including MLS laser therapy, EPAT/shockwave, regenerative injections, and image-guided procedures. Treatment is sequenced from least invasive to most invasive, and we explain the rationale at every step.

When is surgery considered?

Surgery is reserved for cases that fail 3-6 months of well-structured conservative care, when there is structural pathology (severe deformity, complete tear, advanced arthritis), or when imaging shows damage that will not heal without intervention. Our surgeons have performed 3,000+ foot and ankle procedures and prioritize minimally-invasive techniques whenever appropriate. We discuss recovery timelines, return-to-activity milestones, and realistic outcome expectations before any procedure is scheduled.

Recovery timeline and prevention

Recovery from foot pain varies based on severity and chosen treatment path. Conservative cases often improve within 4-8 weeks with consistent adherence to the protocol. Post-procedural recovery may range from a few days (in-office procedures) to several months (reconstructive surgery). Long-term prevention involves footwear assessment, activity modification, structured strengthening, and regular check-ins with your podiatrist if you have a history of recurrence. We provide written home-exercise plans and digital follow-up support.

Related Care at Balance Foot & Ankle

Clinical navicular services at our Howell and Bloomfield Hills offices.

Custom OrthoticsFoot BracingFlat Feet Treatment