Introduction

Tarsal coalition (TC) is a condition characterised by the abnormal fusion of two or more of the small bones in the foot, known as the tarsal bones.¹ Most people with TC are born with the condition; however, symptoms often don’t appear until later in childhood or during the teenage years, when the bones start to harden. At that point, the fused bones can cause foot pain, stiffness, and flat feet, which can interfere with daily physical activities.¹

TC affects approximately 1 to 3% of the population, but because some people don’t manifest symptoms, some studies suggest that the number could be higher, possibly up to 13%.² It is also common for TC to affect both feet simultaneously.²

As soon as symptoms interfere with daily life, non-surgical treatments are recommended as an initial line of treatment. These include resting, physical therapy, orthotics, or a walking boot. But in many cases, these options only offer short-term relief, in which case surgery is recommended to help with pain and restore mobility.¹

There are two main types of surgery used to treat TC: resection, which removes the abnormal fusion and attempts to restore normal joint movement, and arthrodesis, which fuses the bones.² 

If you or your child has been diagnosed with TC and is considering surgery, this article will talk you through the two main procedures, resection and arthrodesis.

Pathophysiology and Classification

TC usually develops during fetal development, due to a genetic mutation that affects how the tarsal bones in the foot form and separate.³ Instead of developing as separate bones, two or more of them stay connected by a bridge of tissue, typically involving the calcaneus, talus, and navicular bones.^1,3 However, in rare cases, it can also be acquired later in life due to injury, infection, or arthritis.

The type of tissue forming this connection determines the kind of coalition:³

• Fibrous (synfibrosis): connected by fibrous tissue
• Cartilaginous (synchondrosis): connected by cartilage
• Osseous (synostosis): fully fused by bone 

The two most common types are:³

• Calcaneonavicular coalition (CNC): a fusion between the calcaneus and navicular bones
• Talocalcaneal coalition (TCC): a fusion between the talus and calcaneus bones

To diagnose TC, an initial screening consisting of a standard X-ray is performed. This can sometimes reveal classic signs, such as the “anteater nose” (often seen in CNC) or the “C-sign” (seen in TCC). However, more advanced imaging is required in many cases, which can provide more information regarding the type of TC. A CT scan can show detailed views of the bones, and an MRI can help visualise soft tissues.³

Indications for surgical intervention

Your doctor may suggest surgery for you or your child if:¹

• Conservative, non-surgical treatment has failed 
• Pain and stiffness continue to affect daily activities

The decision to move forward with surgery depends on several factors. These include the type of coalition, your age, and whether there’s any damage or arthritis.

Surgical options

Resection

Resection is often the preferred surgical option for children or teenagers, especially those who are active, have flexible feet, and no significant joint damage. This is because the goal of resection is to restore normal joint movement, which can be more difficult to achieve in older individuals due to stiffness or arthritis.²

During the procedure, the surgeon removes the abnormal bridging tissue or bone connecting two tarsal bones. This surgery is typically done under general anaesthesia.⁴ There are two main approaches to resection:

Open approach

This is the traditional and most commonly used method. The surgeon makes a large incision and directly removes the coalition. Then, a material, often fat, tendon, or muscle tissue, is placed in the gap. This is called an interposition graft, and its purpose is to prevent the bones from fusing again. Fat is commonly preferred because it has a lower chance of stimulating regrowth compared to muscle tissue.^4,5

Possible complications from open resection include infections, hematomas, and neuromas.⁶

Arthroscopic approach

The arthroscopic approach is considered less invasive than traditional open surgery. It involves making small incisions and using a small camera and tools to help visualise and remove the coalition. This method typically results in a smaller scar, making it more appealing from a cosmetic viewpoint. This frequently leads to a quicker recovery.^4,6

However, studies have shown that people who undergo arthroscopic resection may have a higher chance of needing a second surgery, as symptoms can sometimes persist after the first operation. Moreover, the long-term outcomes of arthroscopic surgery are still not fully understood and remain an area of ongoing research.⁴

Arthrodesis (fusion)

Arthrodesis, often referred to as fusion, is more commonly recommended for adults, particularly when resection hasn’t worked or when there is joint degeneration or arthritis. Instead of preserving movement, this surgery focuses on relieving pain by eliminating motion at the affected joint.⁷

During the procedure, the surgeon removes the cartilage between the bones. The bones are forced to heal together into a single unit. Although this means the joint will no longer move, most people experience significant pain relief.

There are several types of fusion surgery depending on which joints are involved:

• Subtalar arthrodesis: fuses the talus and calcaneus bones. This is often used for talocalcaneal coalitions
• Triple arthrodesis: fuses three joints: the talus, calcaneus, navicular, and cuboid. It’s typically used when multiple joints are involved or when a previous surgery didn’t work
• Talonavicular fusion: fuses the talus and navicular bones 

While fusion is effective in providing long-term pain relief, it comes with limitations. Since fusing the bones reduces mobility, over time, this can place extra stress on the nearby joints, possibly leading to arthritis. Other risks include joint stiffness, nonunion (this is when the bones don’t heal together properly), and changes in walking patterns or gait.

Key comparisons between surgical approaches 

• Resection is usually best for young, active children who want to preserve joint motion
• Arthrodesis is more often recommended for older adults or those with severe coalitions or joint damage
• Resection allows the foot joints to move normally, while fusion stops movement at the joint, at the cost of mobility
• Arthroscopic resection offers a shorter hospital stay and smaller scars, but the surgery takes longer, and there’s a higher chance of needing a second operation later
• Open resection involves a longer healing period up front, but generally leads to better long-term outcomes

Postoperative care 

After resection

After resection surgery, the foot is immobilised in a below-knee splint, and weight-bearing is avoided for about 8 to 10 days. After that, walking can resume by utilising a walking boot, and physiotherapy is started to restore strength and mobility. Most children and teens can return to regular activities within 2 to 3 months, depending on how quickly they heal.^3,4

After arthrodesis

Recovery from arthrodesis generally takes longer, as the fused bones have to heal properly together. For the first 6 to 8 weeks, a cast or brace is worn, with non-weight-bearing. During healing, screws or pins can also be used to stabilise the bones. Once X-rays confirm that the fusion is progressing properly, one can gradually begin putting weight on the foot. Physical therapy is then recommended to rebuild strength and walking function.³

FAQs

How long does it take to recover from tarsal coalition surgery?

Recovery can vary from person to person, but most people heal within 6 to 12 months after tarsal coalition surgery. The exact timeline depends on factors such as age, the severity of the coalition, the type of surgery (resection or arthrodesis), and whether arthritis or other issues are present. Some individuals may recover sooner, while others, particularly the older population, may take longer.

How successful is tarsal coalition surgery?

Surgery for tarsal coalition is generally very successful. Approximately 8 out of 10 surgeries have good outcomes. Clinical success rates are about 81% for calcaneonavicular coalitions (CNCs) and 79% for talocalcaneal coalitions (TCCs).⁸

How serious is the tarsal coalition?

Tarsal coalition isn’t life-threatening, but in more severe cases, it can limit movement, cause pain, and make walking or sports difficult. Treatment is usually recommended to improve comfort and restore daily function, especially in active children and teens.

Is a tarsal coalition a disability?

While not always disabling, tarsal coalition can affect how the foot moves and may lead to long-term problems, such as arthritis or changes in gait. In some cases, it can impact a person’s ability to stay active or walk comfortably, which may qualify as a functional disability depending on severity.⁹

Summary

Tarsal coalition is a common cause of foot pain in children and adolescents. When non-surgical treatments are no longer effective, surgical intervention can provide meaningful relief and improve mobility. Among the available options, open resection with fat interposition remains the gold standard. While arthroscopic resection offers cosmetic and recovery benefits, more long-term research is needed to confirm its effectiveness. Arthrodesis, or joint fusion, is generally reserved for more complex cases, particularly those involving joint degeneration or failed prior surgery.