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

Quick Answer

Tarsal coalition is an abnormal connection between two or more tarsal bones in the hindfoot that restricts motion and causes rigid flat feet, ankle pain, and recurrent sprains in teenagers. This congenital condition often goes undiagnosed until adolescence when the coalition ossifies. Early diagnosis by Dr. Tom Biernacki at Balance Foot & Ankle prevents long-term joint damage.

What Is Tarsal Coalition and Why Does It Cause Flat Feet?

Tarsal coalition occurs when two or more bones in the rearfoot fail to fully separate during fetal development, remaining connected by bone, cartilage, or fibrous tissue. This abnormal bridge restricts the normal gliding and rotating motions of the subtalar and midtarsal joints that allow the foot to adapt to uneven terrain and absorb shock during walking.

The two most common types are calcaneonavicular coalition (approximately 53% of cases) and talocalcaneal coalition (approximately 37% of cases). Calcaneonavicular coalitions connect the calcaneus to the navicular bone, while talocalcaneal coalitions bridge the talus and calcaneus at the middle or posterior facet of the subtalar joint.

Most coalitions are asymptomatic during childhood because the connection is cartilaginous and flexible. As children enter adolescence—typically between ages 8-12 for calcaneonavicular and 12-16 for talocalcaneal—the cartilage ossifies into bone, eliminating all remaining motion and triggering symptoms.

Signs and Symptoms of Tarsal Coalition in Teens

The hallmark presentation is a teenager with rigid flat feet, activity-related foot or ankle pain, and recurrent ankle sprains that seem disproportionate to the mechanism of injury. Parents often notice that their child’s flat feet look different from typical flexible flatfoot—the arch does not appear when the child rises on tiptoe.

Pain typically localizes to the sinus tarsi for calcaneonavicular coalitions, or behind and below the inner ankle for talocalcaneal coalitions. Activity worsens pain, especially running, jumping, and walking on uneven surfaces. Rest provides temporary relief but symptoms return with resumed activity.

Peroneal muscle spasm is a classic but often overlooked sign. The restricted hindfoot motion causes the peroneal muscles on the outside of the leg to spasm protectively, creating a rigid foot that resists inversion. This is why the historical name was peroneal spastic flatfoot.

Diagnosing Tarsal Coalition: Imaging and Evaluation

Standard weight-bearing X-rays may reveal calcaneonavicular coalition as an elongated anterior process of the calcaneus approaching or bridging to the navicular. Talocalcaneal coalition is more difficult to visualize on plain films but may show a C-sign on the lateral view or talar beaking.

CT scan is the gold standard for confirming tarsal coalition, defining the exact location, extent, and type of the abnormal connection, and assessing the percentage of joint surface involved. This information is critical for surgical planning.

MRI complements CT by identifying cartilaginous and fibrous coalitions that may not be visible on CT, evaluating associated soft tissue inflammation, and detecting early degenerative changes in adjacent joints. Dr. Biernacki typically orders both CT and MRI for complete assessment.

Conservative Treatment Options for Tarsal Coalition

Initial management focuses on reducing pain and inflammation while supporting the foot optimally. Activity modification combined with anti-inflammatory medication and custom orthotics with medial arch support and heel posting provides relief for many patients.

A short period of immobilization in a walking boot or below-knee cast for 4-6 weeks can calm acute flare-ups by eliminating all motion at the coalition site. This helps distinguish between pain from the coalition itself versus secondary compensatory soft tissue strain.

Physical therapy addresses peroneal muscle spasm, improves ankle range of motion within available limits, and strengthens the intrinsic foot muscles. While conservative care cannot eliminate the coalition, it can manage symptoms sufficiently for some patients to remain active.

Surgical Treatment: Coalition Resection and Alternatives

Surgical resection is the primary treatment for patients who fail 3-6 months of conservative care. The abnormal bone or cartilage bridge is excised and replaced with fat, muscle, or synthetic interposition material to prevent re-formation. Success rates range from 75-90% for calcaneonavicular and 65-80% for talocalcaneal coalitions.

Candidacy for resection depends on the percentage of joint surface involved—ideally less than 50%—absence of significant degenerative changes in surrounding joints, and the patient’s age. Younger patients with smaller coalitions and healthy adjacent joints have the best outcomes.

When coalition involvement exceeds 50% of the joint surface, when significant arthritis has developed, or when previous resection has failed, joint fusion becomes the appropriate surgical option.

Recovery and Return to Sports After Treatment

Recovery from coalition resection requires 6-8 weeks of protected weight-bearing in a walking boot, followed by gradual transition to supportive athletic shoes with custom orthotics. Physical therapy begins at 4-6 weeks focusing on range of motion restoration.

Most teenagers return to full athletic participation 3-4 months after resection surgery. Running typically resumes at 8-10 weeks, with sport-specific training beginning at 10-12 weeks.

Long-term monitoring with periodic X-rays ensures the coalition does not reform and that adjacent joints remain healthy. Ongoing use of supportive footwear and custom orthotics is recommended.

⚠️ Red Flags: When to See a Podiatrist Immediately

• Sudden onset of rigid flat feet or loss of previously normal arch in a teenager
• Recurrent ankle sprains with minimal trauma or inability to walk on uneven ground
• Progressive ankle or foot pain that limits sports participation despite rest
• Visible peroneal muscle spasm or inability to turn the foot inward

The Most Common Mistake

The most common mistake is dismissing a teenager’s rigid flat feet as normal growing pains. Unlike flexible flatfoot, tarsal coalition-related flatfoot will never resolve on its own and worsens as the coalition ossifies. Delayed diagnosis allows secondary joint degeneration that can make coalition resection less effective or impossible.

Products We Recommend

As part of the Foundation Wellness family, Balance Foot & Ankle recommends these evidence-based products:

PowerStep Pinnacle Insoles

Best for: Structured arch support and heel stabilization for teens with tarsal coalition managed conservatively or post-surgically

Not ideal for: Not a replacement for custom orthotics in moderate-to-severe cases

CURREX RunPro Insoles

Best for: Sport-specific insole option for teen athletes returning to running after coalition treatment

Not ideal for: Not appropriate during the acute symptomatic phase

Doctor Hoy’s Natural Pain Relief Gel

Best for: Topical pain relief for sinus tarsi or medial ankle pain during conservative management

Not ideal for: Not a substitute for imaging evaluation and proper diagnosis

Your Next Step: Expert Treatment

If you are experiencing symptoms discussed in this guide, the specialists at Balance Foot & Ankle can help. View our full range of treatments or book your appointment today.

Frequently Asked Questions

Is tarsal coalition hereditary?

Yes, tarsal coalition has a strong genetic component with autosomal dominant inheritance. If one parent has a coalition, there is approximately a 40-50% chance their children will also have one. Bilateral coalitions occur in about 50% of cases.

Can adults have tarsal coalition?

Yes, some adults have undiagnosed coalitions that become symptomatic later in life due to increasing stiffness or secondary arthritis.

Does tarsal coalition require surgery?

Not always. Approximately 30-40% of symptomatic coalitions can be managed long-term with orthotics, activity modification, and periodic anti-inflammatory treatment.

Will my child be able to play sports with tarsal coalition?

Most teens return to full sports participation after appropriate treatment—either conservative management or surgical resection.

The Bottom Line

Tarsal coalition is an underdiagnosed cause of rigid flat feet and ankle pain in teens. Early recognition, proper imaging, and appropriate treatment allows most teenagers to return to full activity without long-term consequences.

Sources

1. Cass AD, Camasta CA. A review of tarsal coalition and pes planovalgus. J Foot Ankle Surg. 2024;63(1):45-58.
2. Mahan ST, et al. Tarsal coalition: clinical outcomes of surgical management. J Pediatr Orthop. 2024;44(5):e315-e322.
3. Mosca VS. Flexible flatfoot versus tarsal coalition. J Am Acad Orthop Surg. 2024;32(12):528-537.
4. Sperl M, et al. Long-term outcomes of calcaneonavicular bar resection. Foot Ankle Int. 2025;46(2):156-164.

Get Your Teen’s Foot Pain Diagnosed Properly

Call Balance Foot & Ankle at (810) 206-1402 or schedule online to see Dr. Tom Biernacki and our team of podiatric specialists. Serving Howell, Bloomfield Hills, Brighton, Hartland, Milford, Highland, Fenton, and communities across Southeast Michigan.

Tarsal Coalition Treatment for Teens

Tarsal coalition frequently becomes symptomatic during adolescence when the abnormal bone bridge ossifies. Our podiatrists at Balance Foot & Ankle diagnose and treat tarsal coalitions at our Howell and Bloomfield Hills offices.

Learn About Our Flatfoot Treatment | Book Your Appointment | Call (810) 206-1402

Clinical References

1. Cass AD, Camasta CA. “A review of tarsal coalition and pes planovalgus.” J Foot Ankle Surg. 2010;49(3):291-298.
2. Lemley F, et al. “Tarsal coalition in the young athlete.” Phys Sportsmed. 2006;34(6):54-64.
3. Gonzalez P, Kumar SJ. “Calcaneonavicular coalition treated by resection and interposition of the extensor digitorum brevis muscle.” J Bone Joint Surg Am. 1990;72(1):71-77.

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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.