Accessory Navicular Syndrome: Symptoms, Treatment, Surgery

Accessory navicular syndrome is pain on the inner arch of the foot caused by an extra bone or piece of cartilage next to the navicular bone. Most people with this extra bone never have symptoms. When pain does start, rest, shoe changes, arch support and a short period of immobilization help most patients. Surgery is the next step if they fail.

If you or your child has a tender bump on the inside of the midfoot, this guide covers what it is, how it is diagnosed, what treatment usually works, and when it is time to see a specialist. It is written for patients and parents in Las Vegas and beyond. It is general education, not a diagnosis.

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TL;DR

An accessory navicular is an extra bone on the inner arch. It is a common anatomic variant, and most people never feel it.
It becomes a syndrome when the bone or the tendon attached to it is irritated, often in the teen years or after a twist, sports load or tight footwear.
Nonsurgical care comes first: activity changes, supportive shoes, orthotics, a boot or cast if needed, and strengthening.
Surgery is considered when 3 to 6 months of good conservative care has not worked. Outcomes in published series are generally strong.
A medial foot bump that is red, swollen or painful with walking deserves an exam and an X-ray, not months of guessing.

What is accessory navicular syndrome?
What are the symptoms of accessory navicular pain?
How is accessory navicular syndrome diagnosed?
How do you treat accessory navicular syndrome without surgery?
Can running or sports cause navicular pain?
When is surgery for accessory navicular needed?
Nonsurgical vs surgical care at a glance
Our perspective: start conservative, plan clearly
Care for accessory navicular pain in Las Vegas
What to bring and ask at your visit
FAQ
Sources

What is accessory navicular syndrome?

Accessory navicular syndrome happens when an extra bone beside the navicular, on the inner side of the foot, becomes painful. The pain comes from the bone’s connection to the main navicular, from pressure against shoes, or from strain on the posterior tibial tendon, which attaches in this spot.

The navicular sits in the medial arch, just above the instep. Some people are born with an extra bone next to it, called the accessory navicular, which may or may not be fused to the main bone. Accessory ossicles like this result from ossification centers that never fused, and they can also follow earlier trauma.

The extra bone is not a disease. The syndrome is the painful state. That distinction matters because an X-ray showing an accessory navicular does not prove it is the source of your pain.

How common is it?

Estimates vary a lot depending on how the studies were done. A radiology review lists the accessory navicular at roughly 2% to 21% of people. The American Academy of Orthopaedic Surgeons notes the range is 2% to 21% and that it is more common in females. Pediatric orthopaedic educators describe it as present in at least 14% of the population, rarely symptomatic, and commonly on both feet.

The practical takeaway: many people have one, few have pain, and if you have pain in one foot, the other foot probably has the same extra bone.

The three types

Clinicians usually sort the bone into three types, and the type shapes the risk of pain, according to FootCareMD:

Type	What it is	Why it matters
Type 1	A small sesamoid-like bone inside the posterior tibial tendon	Usually painless and found by accident
Type 2	A larger fragment joined to the navicular by a cartilage interface (synchondrosis)	The classic painful type; motion at the interface and tendon pull irritate it
Type 3	A fused, prominent navicular (sometimes called a cornuate navicular)	Can still cause pressure pain in tight shoes

A radiology reference describes the syndrome, also called os naviculare syndrome, as occurring when a Type 2 bone becomes painful from movement at that junction.

What are the symptoms of accessory navicular pain?

The main symptoms are pain and tenderness over a bony bump on the inner arch, often with swelling or redness. Pain typically worsens with walking, running, jumping or tight shoes, and eases with rest. Some people also notice the arch looks flatter on that side.

Look for this pattern:

A bump on the inside of the midfoot, roughly halfway between the heel and the big toe, just above the arch.
Tenderness when you press on it, or when a shoe rubs it.
Swelling or redness over the bump after activity.
Aching along the arch or behind the inner ankle bone, where the posterior tibial tendon runs.
Pain that builds during sports that load the arch, such as soccer, basketball, running and dance.

For children and teens, the typical story is a new ache at around the age the bone finishes maturing. Symptoms often emerge during adolescence as the bone calcifies or after a minor injury. A parent might notice a child limping after practice or refusing to wear a particular pair of cleats.

A realistic example

A 14-year-old club soccer player starts complaining that her left arch hurts in cleats. There was no single injury, but the season just ramped up. Her parents see a firm bump on the inner foot that is pink after games. An exam finds tenderness exactly over the bump and a flatter arch when she stands. An X-ray shows a Type 2 accessory navicular, and the other foot has the same extra bone with no pain. That last detail is a useful clue: the bone is probably an ordinary variant that has become irritated, not a new injury.

This is an illustration of a common pattern, not a patient story.

Swelling and other causes of medial foot pain

Not every inner-arch ache is an accessory navicular. Posterior tibial tendon problems, flat feet, stress fractures and ordinary sprains can feel similar. If swelling is the main complaint, our guide to foot and ankle swelling and its red flags explains what to watch for. For tendon problems that can overlap, see our article on posterior tibial tendon dysfunction treatment.

How is accessory navicular syndrome diagnosed?

Diagnosis combines a physical exam with a weight-bearing X-ray. The doctor presses over the bump, watches how you stand and walk, and checks the posterior tibial tendon. X-rays confirm the extra bone. An MRI is reserved for unclear cases, where it can show inflammation that proves the bone is the pain source.

The steps usually go like this:

History. When did pain start, what activities provoke it, what shoes make it worse, and has there been a twist or fall?
Exam. Tenderness directly over the prominence, arch height standing and sitting, and strength when you rise onto your toes.
X-rays. Radiographs are best for the initial evaluation of accessory ossicles and show the type and size of the bone.
MRI when needed. Imaging helps when the exam and X-ray do not line up with the pain.

Why MRI matters: many people have this bone and no pain, so finding it is not enough. A study of MRI findings in people with and without symptoms found that edema in the os naviculare and in the navicular tuberosity was significantly associated with medial foot pain. In plain terms, a bright fluid signal in the bone tells the doctor the bone is truly irritated, rather than being an innocent bystander.

See a foot and ankle specialist promptly if there is severe pain, an inability to bear weight, fever with a red hot foot, or numbness. Those are not typical for this condition and need a different evaluation. If you have diabetes, any new foot redness or sore deserves a same-week visit.

How do you treat accessory navicular syndrome without surgery?

Treatment starts with rest from aggravating activity, better footwear and arch support. A boot or short cast calms severe flares, and physical therapy strengthens the posterior tibial tendon. This approach is first-line, and published figures suggest it resolves symptoms in roughly 70% of patients with symptomatic bones.

The conservative toolkit, roughly in the order most patients meet it:

Activity modification. Cut back on running, jumping and long standing days for a few weeks. This is not forever; it lets the irritated area calm down.
Footwear changes. Shoes with a firm heel counter, a supportive midsole and a roomy inner arch. Avoid anything that presses on the bump.
Padding. A donut-shaped pad or soft cushion over the prominence can reduce rubbing.
Arch supports or custom orthotics. These reduce the pull on the tendon and the motion at the interface.
A walking boot or short cast. For a painful flare, immobilization for a few weeks is a common step.
Anti-inflammatory measures. Ice after activity and, if your doctor approves, over-the-counter anti-inflammatories.
Physical therapy. Strengthening of the posterior tibial tendon and the muscles that hold the arch.

A pediatric review of accessory ossicles concludes that most can be managed nonsurgically, and POSNA calls nonoperative treatment the mainstay with surgery as an option for those who continue to have symptoms. Our approach is the same, and we explain it further in how conservative foot care relieves pain and can prevent surgery.

Do orthotics help?

Often yes, mainly when the arch is flat and the tendon is overworked. An orthotic gives the arch a platform so the tendon does not have to work as hard, and a cutout or soft area can relieve pressure over the bump. They are part of a plan, not a cure for the bone itself. Our article on orthotics for foot pain walks through the options, and custom orthotics explains how they are made.

Can an accessory navicular go away?

The extra bone does not dissolve. In many people, though, the pain does go away as the irritation settles or as growth finishes, even though the bone stays. A bump that was painful at 13 can be a quiet bump at 18. Others have pain that comes back with every season of sports, which is when a longer-term plan matters.

Shoes for growing feet

Footwear choices matter for kids with a painful medial bump. A shoe with a soft, flexible upper over the arch and enough room around the midfoot is easier on the bump than a stiff, narrow one. If you want background on barefoot shoes and children’s foot development, it can help frame the questions to bring to your child’s appointment. Whether a particular shoe suits a particular foot is something a podiatrist should check in person.

Can running or sports cause navicular pain?

Running and sports do not create the accessory bone, but they can make it hurt. Repeated pushing off, cutting and landing pulls on the posterior tibial tendon at its attachment, and cleats or skates can press on the bump. Pain often flares when training load rises quickly.

The sports that show up most are soccer, basketball and dance. Adolescent athletes with this condition have been reported to have a higher risk of failing conservative treatment and often expect a fast return to play. That is one reason to build a clear timeline with your doctor, not just wait and see.

Ways to protect the arch while you stay active:

Increase training gradually instead of jumping in after a break.
Replace worn shoes. Midsoles collapse before the upper looks worn.
Break in new cleats and skates slowly, and pad the bump if they press on it.
Add calf, ankle and arch-strengthening work to your week.
Stop and get checked if pain lasts after rest or is present at night.

In Las Vegas, there is an added wrinkle: hot pavement, long days on hard indoor courts and the popularity of sandals and flip-flops with no arch support. For a flare, switch to supportive closed shoes for daily wear.

When is surgery for accessory navicular needed?

Surgery is considered when 3 to 6 months of well-done conservative care has not controlled the pain. In one study of symptomatic patients, about 28.7% eventually needed an operation, and nonsurgical treatment that failed did so at a median of 5.2 months.

The figures come from a retrospective case-cohort study presented at AAOS 2024 on children and adolescents. It is one study, so treat it as a guide to the general picture, not a promise for any single patient.

Signs that surgery is worth discussing:

Pain still limits walking, school or sports after 3 to 6 months of consistent nonsurgical care.
Symptoms keep returning after each break from treatment.
The bump is chronically inflamed and shoes cannot be adjusted to avoid it.
Imaging shows clear inflammation at the bone interface and the exam matches.

Surgery is a choice, not an emergency. A second opinion is reasonable, and we offer them.

What does surgery involve?

The standard operation is called the Kidner procedure. The surgeon removes the accessory bone and, where needed, reattaches the posterior tibial tendon so the arch keeps its support. If a flatfoot is present, the surgeon may address that too. A systematic review of surgical treatment pooled 520 patients (614 feet) who had surgery for symptomatic accessory navicular, which shows how widely the operation is studied.

In adolescent athletes, surgeons report high rates of pain relief and return to activity, and the research summaries we reviewed cite success above 90%. Individual results depend on age, the type of bone, alignment and how closely you follow rehab.

What is recovery like?

Recovery varies by surgeon and technique, so your own plan is the one to follow. In general, expect a period in a cast or boot with limited or no weight on the foot, then a gradual return to walking, then strengthening and a staged return to sport. Running and competition are usually later milestones, over a few months, not weeks.

Tips that help in any plan:

Keep the foot elevated early on to limit swelling.
Keep the dressing and cast dry and intact.
Do the exercises you are given; the tendon needs them.
Do not return to sport until your surgeon clears you.
Call right away for fever, spreading redness, drainage or calf pain and swelling.

Our post-surgery foot care steps cover the basics of a safe recovery.

Nonsurgical vs surgical care at a glance

Nonsurgical care is the right start for almost everyone, because it avoids operative risks and works for most. Surgery fits patients whose pain persists despite proper treatment. The table below shows how the two paths compare on the points families ask about most.

	Conservative care	Surgery (Kidner procedure)
Who it is for	Nearly everyone with a first painful episode	Persistent pain after 3 to 6 months of care
What it involves	Activity changes, shoes, orthotics, boot or cast, therapy	Bone removal, tendon reattachment if needed
Downtime	Usually none to a few weeks in a boot	A period of protected weight bearing, then rehab
Main trade-off	Pain may return; takes patience	Anesthesia, incision and rehab commitment
Typical outcome	Works in roughly 70% of symptomatic cases	Strong pain relief in published series

Our perspective: start conservative, plan clearly

We see accessory navicular pain as a problem of load and fit before it is a problem of bone. The extra bone has usually been there for years. What changed is the shoe, the sport, the growth spurt or the arch. So we begin by asking what changed, then take the pressure off with footwear, support and a realistic activity plan.

At Stride Foot & Ankle, Dr. Nahad Wassel is a board-certified foot and ankle surgeon, and our practice prioritizes conservative treatment before surgery. That order is deliberate. We would rather you get back on your feet with a good orthotic and a smart plan than have an operation you did not need.

We also believe in honest timelines. If three months of consistent care has not helped, we say so, and we talk through the surgical option, the risks and what rehab asks of you. Families should leave with a plan they understand, not a list of vague warnings.

Two things we ask of every patient: bring the shoes you wear most, and tell us what hurts and when. Those two details often explain more than the X-ray does.

— Ramil

Care for accessory navicular pain in Las Vegas

If you are in Las Vegas and want a clear answer on a painful inner-arch bump, we can examine the foot, review imaging and build a plan. Our general foot and ankle care includes evaluation and orthotics. If surgery is the right next step, you can learn about surgical care with Dr. Wassel. We treat all ages, including teens and children, and we also provide second opinions.

Prices are not published on our site, and coverage depends on your plan, so call the office to ask about billing and insurance before your visit.

Parents may also find these guides useful: pediatric foot pain causes and care, flat feet in children and Sever’s disease treatment, a heel condition often seen in the same age group.

What to bring and ask at your visit

A focused visit gets answers faster. Bring your child’s sports schedule, the shoes that hurt, and any earlier X-rays or MRI reports.

Questions worth asking:

Which type of accessory navicular is this, and is it fused?
Is the bone the source of the pain, or is something else going on?
What is the plan for the next 3 months, and what would make us change it?
How long before my child can return to sport, and in what stages?
If surgery comes up, what is the recovery timeline and what are the risks?

FAQ

How do you know if you have accessory navicular syndrome?

The typical signs are a bony bump on the inner arch that is tender, sometimes red or swollen, and sore with activity or tight shoes. Only an exam and X-ray can confirm it. MRI may be used when the source of pain is unclear.

Does accessory navicular syndrome always need surgery?

No. Most patients improve with conservative care such as activity changes, supportive shoes, orthotics, a boot or cast, and strengthening. Surgery is usually reserved for people whose pain continues after 3 to 6 months of proper nonsurgical treatment.

Is accessory navicular pain dangerous?

The extra bone itself is a common variant and is not dangerous. The pain can still limit sports and daily life, so it deserves care. Severe pain, fever, a hot red foot or inability to bear weight need prompt evaluation, since they point to other problems.

Can adults get accessory navicular syndrome?

Yes. Symptoms often begin in adolescence, but adults can develop pain after a twist, a change in activity or flatfoot changes in the tendon. The same evaluation and treatment steps apply, and surgery series include adult patients.

Who should I see for accessory navicular pain in Las Vegas?

A podiatrist or foot and ankle surgeon can examine the foot, order imaging and guide treatment. At Stride Foot & Ankle, Dr. Nahad Wassel, a board-certified foot and ankle surgeon, sees patients of all ages. Request an appointment through our website.