Understanding Accessory Bones in the Foot
Have you ever noticed a small bump on your foot and wondered if it was normal? You may be surprised to learn that some people are born with extra bones in their feet. These are called accessory bones—a common anatomical variation that is usually harmless but can sometimes lead to pain or confusion during diagnosis.
What Are Accessory Bones?
Accessory bones (also called ossicles) are additional bone fragments that develop during normal bone formation. Most people have 26 bones in each foot, but some may have extra bones due to variations in how their bones fused during childhood. These bones are not the result of injury and are usually present from birth.
Common Types of Accessory Bones in the Foot
There are over 40 types of accessory bones documented in the foot, but only a few tend to cause symptoms. Some of the most common include:
1. Accessory Navicular
Located on the inner side of the foot, just above the arch.
Often becomes painful in adolescence or during increased activity.
May cause swelling and tenderness in the arch area.
2. Os Trigonum
Found at the back of the ankle near the heel.
Can cause pain in ballet dancers, footballers, and athletes who frequently point or plantarflex the foot.
Often associated with posterior ankle impingement.
3. Os Peroneum
A small bone found near the base of the fifth metatarsal, embedded in the peroneus longus tendon.
Rarely painful, but can be involved in peroneal tendon injuries or chronic lateral foot pain.
When Do Accessory Bones Cause Problems?
Most accessory bones are asymptomatic and go unnoticed. However, they can become problematic when:
There is trauma or overuse.
They interfere with tendon function or joint movement.
They are mistaken for fractures on X-rays.
Footwear or activity level places repetitive pressure on the area.
Symptoms of a Symptomatic Accessory Bone
Localised pain or swelling
Redness or tenderness to touch
Worsening pain with activity or certain footwear
Difficulty walking or performing sports
Diagnosis
At Bondi Podiatry, we conduct a thorough clinical examination, often supported by X-rays, ultrasound or MRI if needed. This helps us distinguish between accessory bones, fractures, and other sources of foot pain.
Treatment Options
Treatment depends on the location and severity of symptoms, and may include:
Rest and activity modification
Custom orthotics to offload the affected area
Footwear advice to reduce pressure and improve biomechanics
Physical therapy for strengthening and flexibility
Anti-inflammatory medication or icing
In persistent cases, surgical removal may be considered
When to See a Podiatrist
If your child complains of unexplained foot pain, or if you’ve noticed a bony lump that is painful, it’s worth seeking professional advice. Early diagnosis and targeted care can make a big difference—especially for growing feet or active adults.
Bondi Podiatry is here to help with all foot and ankle concerns.
We’re experienced in managing accessory bones in children, teens, and adults.
📍 Visit us at 301/251 Oxford Street, Bondi Junction
📞 Call (02) 8971 1682 or book online
Your feet carry you through life—let’s keep them strong, pain-free, and supported.
