Accessory navicular and medial foot pain

What It Is

An accessory navicular is an extra bone or piece of cartilage located on the inner side of the foot, just above the arch. It is a normal variant from which the tuberosity of the navicular develops from a secondary ossification centre that fails to unite during childhood.
Not everyone has this extra bone, but for those who do, it can sometimes cause pain and discomfort, especially in active children.

What Causes It

This condition occurs during foetal development when extra cartilage forms near the navicular bone. Over time, this cartilage can harden into bone. Genetics can play a role, so it may run in families.

Different Types

There are three main types of accessory navicular bones:

• Type I: Small bone embedded within the posterior tibial tendon. Usually painless.
• Type II: Larger and more triangular, connected to the navicular bone by cartilage. This type is most likely to cause pain due to irritation.
• Type III: A fused version where the extra bone and the navicular bone are joined, creating a larger, single bone.

Symptoms

Many children with an accessory navicular have no symptoms. However, some may experience:

• Pain or aching in the inner side of the foot, especially after physical activity.
• Redness and swelling over the bony area.
• Difficulty wearing shoes due to irritation from pressure.
• Flat feet or a fallen arch, causing the foot to roll inward.

Possible Complications

If left untreated or aggravated, symptoms could worsen and lead to:

• Chronic pain or discomfort.
• Difficulty walking or participating in sports.
• Inflammation of the posterior tibial tendon, which supports the arch.

How It Can Be Diagnosed

A pediatrician or orthopedic specialist can diagnose an accessory navicular through:

• Physical Examination: Checking for pain, swelling, and foot shape.
• X-rays: Confirming the presence and type of accessory navicular.

Treatment Options

Non-Surgical Treatments:

• Rest and Activity Modification: Reducing activities that cause pain.
• Ice Therapy: Applying ice packs to reduce swelling.
• Orthotic Devices: Custom shoe inserts to support the arch and relieve pressure.
• Immobilization: Using a cast or walking boot to allow the area to heal.
• Physical Therapy: Exercises to strengthen the foot muscles and improve flexibility.
• Pain management: Over-the-counter pain relievers like ibuprofen for pain and inflammation.

Surgical Treatment:

• Surgery is considered if non-surgical treatments fail. It involves removing the accessory navicular and repairing the posterior tibial tendon. This is usually successful in relieving pain and restoring normal foot function.

Recovery

• Non-Surgical: Symptoms typically improve within weeks to a few months with proper rest and care.
• Surgical: Full recovery may take 6-8 weeks. Physical therapy is often recommended to restore strength and flexibility. Children can usually return to normal activities once fully healed.

How It Can Be Prevented

Since it’s a congenital condition, it can’t be prevented. However, to minimize symptoms:

• Encourage your child to wear supportive shoes with good arch support.
• Avoid activities that cause pain or discomfort.
• Maintain a healthy weight to reduce stress on the feet.

Frequently Asked Questions

Q: Is an accessory navicular common in children?
A: Yes, it’s estimated that 10-15% of people have it, though many are asymptomatic.

Q: Will my child outgrow the pain?
A: Some children may outgrow the pain as their feet develop. However, persistent pain may require treatment.

Q: Can my child play sports with an accessory navicular?
A: Yes, but activity modification and supportive footwear may be needed. If pain persists, consult a specialist.

Q: Is surgery always necessary?
A: No, surgery is a last resort if non-surgical treatments fail to relieve pain.

Q: Will my child’s foot shape change after surgery?
A: No, surgery is designed to relieve pain without altering foot shape or function.