Accessory Navicular Syndrome Treatment In
Lenexa, KS

What Is Accessory Navicular Syndrome?

The accessory navicular is an extra bone or piece of cartilage on the inner side of the foot near the navicular bone, just above the arch. It is also called an os naviculare, os navicularum, or os tibiale externum. It is congenital, meaning the anatomic variation is present from birth even though it may not become clearly visible on X-ray until the cartilage ossifies as a child matures.

The accessory navicular lies in or very near the posterior tibial tendon, one of the major structures that supports the arch. Simply having the extra bone is not the same as having accessory navicular syndrome. The word syndrome describes the painful state that develops when the accessory bone, its connection to the main navicular, or the tendon becomes irritated or inflamed.

Most accessory navicular bones never cause symptoms and need no treatment. Published estimates vary by population and imaging method, with many clinical references placing prevalence around 4% to 14%. Bilateral involvement is common; some clinical references describe the finding in both feet in about half of affected people.

A 2022 retrospective radiographic review from a specialty foot-and-ankle clinic examined 503 patients and 1,006 foot radiographs. It identified an accessory navicular in 117 patients (23.3%) and 194 feet (19.3%); 77 of the affected patients (65.8%) had bilateral findings. Among patients with an accessory navicular, 67.5% were female and 32.5% were male, ages ranged from 19 to 86 years with a mean age of 48.26 ± 14.5 years, and Type I was the most common classification at 42.1%. The authors found no significant difference in accessory-navicular type by sex. Because this was a retrospective, non-probability clinic sample evaluated with plain radiographs rather than a randomized general-population study, its higher prevalence should not be treated as a universal rate.

The Navicular, Posterior Tibial Tendon, And Three Accessory Navicular Types

The human foot has 26 standard bones, but more than 20 named accessory bones and ossicles have been described around the foot and ankle. The accessory navicular is one of the more familiar variants. The navicular is one of the tarsal bones in the midfoot. It sits between the talus toward the rear of the foot and the cuneiform bones toward the forefoot. Together with the calcaneus, talus, cuboid, and three cuneiforms, it is part of the tarsus that forms a stable weight-bearing platform and helps shape the medial arch.

The posterior tibial tendon begins in the lower leg, passes behind the inside of the ankle, and attaches around the navicular region. Its job includes supporting the arch and controlling excessive inward rolling of the foot. An accessory navicular can sit within this tendon or at its insertion, which is why tendon pull and arch mechanics can influence symptoms.

The three accessory navicular types

• Type I: a small, round or oval sesamoid-like ossicle within the posterior tibial tendon, commonly described as about 2 to 3 mm. It is typically the least symptomatic type.
• Type II: a larger triangular, heart-shaped, or bullet-shaped accessory bone beside the navicular, commonly described at about 12 mm. It is joined to the navicular by a cartilage or fibrous bridge called a synchondrosis. Type II is the form most often associated with pain because movement and stress can inflame that connection.
• Type III: the accessory bone has fused to the navicular, creating a larger or horn-shaped medial navicular prominence. This is commonly considered the fused end stage of a Type II accessory navicular.

Why the area becomes painful

Pain can come from direct shoe pressure over the prominence, inflammation where a Type II accessory bone meets the navicular, or traction from the posterior tibial tendon. In some patients, tendon contraction can create tiny movements across the synchondrosis. Repetitive motion may produce inflammation and, over time, degenerative or arthritic change between the two bony surfaces. A large prominence can also alter tendon mechanics, and significant posterior tibial tendon injury is possible in more severe cases.

Symptoms Of Accessory Navicular Syndrome

Symptoms often first appear during adolescence, when cartilage is maturing into bone and sports or activity levels may be increasing. Some people remain symptom-free until adulthood and develop pain only after a sprain, fall, footwear change, or period of heavier activity.

• A visible or easily felt hard bump on the inner side of the midfoot just above the arch.
• Localized tenderness when the bony prominence is pressed.
• Redness, swelling, or skin discoloration over the prominence.
• Vague aching, throbbing, or sharper pain in the medial midfoot or arch.
• Pain during or after walking, running, sports, hiking, dancing, or other repetitive activity.
• Pain with standing or weight-bearing, especially during a flare.
• Discomfort when shoes rub or press against the inside of the foot.
• Difficulty finding shoes that fit comfortably over the prominence.
• A limp or altered gait when pain makes normal push-off uncomfortable.
• Pain that may extend farther down the arch or upward along the inside of the ankle when the posterior tibial tendon is irritated.
• Reduced motion or reluctance to move the foot normally because movement hurts.
• A sudden increase in symptoms after a foot or ankle sprain or other traumatic injury.

Symptoms may affect only one side even when accessory navicular bones are present in both feet. The bony variant itself is not dangerous, but pain that changes walking, sport, or everyday activity should not simply be written off as “an extra bone.”

What Causes Accessory Navicular Syndrome?

The accessory navicular itself is congenital. What changes is the amount of stress, inflammation, or pressure around it.

Common triggers

• Shoe pressure: tight, rigid, or poorly fitting footwear can repeatedly rub the prominence and inflame the overlying skin and soft tissue.
• Sports and overuse: running, jumping, hiking, dancing, prolonged standing, and repetitive loading can irritate the accessory bone or posterior tibial tendon.
• Foot or ankle injury: a sprain, fracture, trip, fall, or direct impact can make a previously painless accessory navicular suddenly symptomatic.
• Adolescent bone maturation: symptoms commonly emerge around puberty as the accessory cartilage ossifies and becomes less tolerant of repetitive motion or shoe pressure.
• Flat feet or fallen arches: a lower arch can increase pull through the posterior tibial tendon and stress the accessory navicular region.
• Posterior tibial tendon irritation: tendinitis, tendon overload, or tendon insufficiency can make the navicular attachment region painful.
• Type II synchondrosis stress: repeated motion between the accessory bone and navicular can inflame the cartilage or fibrous bridge and sometimes lead to degenerative change.

Who is more likely to have one?

Accessory navicular bones can run in families, supporting a genetic component. Some clinical literature also reports variation among populations, including higher prevalence in some Asian groups. Not everyone with the anatomic variant develops symptoms, and having one does not mean the foot will inevitably worsen with age.

How Accessory Navicular Syndrome Is Diagnosed

Diagnosis combines the location and pattern of symptoms with an examination and imaging. The goal is not only to confirm that an accessory navicular exists, but also to determine whether it is actually the source of pain and whether the posterior tibial tendon or foot structure is involved.

History and physical examination

A podiatrist may ask when the pain began, whether it followed a sprain or change in activity, which shoes aggravate it, and whether similar symptoms occur in the other foot. The exam may include:

• Inspecting the medial midfoot for a bony prominence, redness, swelling, or skin irritation.
• Pressing directly over the accessory navicular and the posterior tibial tendon to reproduce tenderness.
• Evaluating arch height, flat-foot mechanics, and how the heel and foot align during standing.
• Checking posterior tibial tendon strength and function.
• Testing ankle and foot motion, muscle strength, and flexibility.
• Watching the way you stand and walk for limping or abnormal mechanics.

Imaging

X-rays are usually the first imaging test and can confirm the accessory navicular, show whether it is Type I, II, or III, and help distinguish the variant from a fracture. MRI or other advanced imaging may be used when pain or inflammation persists, the diagnosis is uncertain, the synchondrosis needs closer evaluation, or posterior tibial tendon damage is suspected.

One reason imaging matters is that an accessory navicular can be mistaken for a navicular tuberosity avulsion fracture or another midfoot/hindfoot injury after trauma. The treatment for a congenital accessory bone is not automatically the same as the treatment for an acute fracture.

Conditions That Can Resemble Or Accompany Accessory Navicular Syndrome

Inner-arch and medial midfoot pain is not unique to accessory navicular syndrome. A careful exam may need to separate the accessory bone from other problems or identify conditions occurring at the same time.

• Posterior tibial tendon dysfunction or tendinitis.
• Flat feet or fallen arches.
• Navicular tuberosity avulsion fracture or another foot fracture.
• Navicular or midfoot stress injury.
• Foot and ankle sprains or strains.
• Midfoot arthritis or degenerative joint pain.
• Other tendon inflammation around the foot and ankle.
• Structural foot deformities that alter arch mechanics.

Nonsurgical Treatment For Accessory Navicular Syndrome

An accessory navicular that does not hurt usually needs no treatment. When it becomes symptomatic, the first goal is to calm inflammation and mechanical stress, then address the footwear, activity, tendon, or arch factors that keep re-irritating the area.

Rest, ice, elevation, and flare control

• Reduce or temporarily stop running, jumping, long walks, or other activity that reproduces pain.
• Apply ice wrapped in a thin towel rather than directly against the skin to reduce pain and swelling.
• Elevate the foot during an acute inflammatory flare when swelling is present.
• Use an oral NSAID such as ibuprofen or a non-NSAID pain reliever such as acetaminophen only when it is appropriate for your health history and medication profile. Some patients also use topical analgesics for short-term symptom relief.

Footwear, padding, and arch support

Softer, supportive shoes can reduce direct rubbing over the bony prominence. A wider or more accommodating upper, cushioning, and strategically placed padding may make everyday footwear more tolerable. Arch support can also reduce workload on the posterior tibial tendon and motion around the painful navicular region.

Over-the-counter inserts may be enough for some patients. Custom orthotics can be useful when flat feet, arch collapse, or individual biomechanics are a major part of the problem.

Immobilization

A removable walking boot or short-leg cast may be used when pain is significant or does not settle with simpler measures. Immobilization gives the accessory navicular, synchondrosis, and tendon time to rest. A common conservative immobilization period is several weeks; some orthopedic protocols use roughly four to six weeks, but the right duration depends on the severity and the structures involved.

Physical therapy

Physical therapy can address calf flexibility, ankle stability, range of motion, balance, and posterior tibial tendon strength. Strengthening is generally introduced after acute inflammation is controlled. Therapy can also guide a gradual return to walking, running, or sport and may reduce recurrence.

Steroid treatment

Some treatment plans use oral or injected corticosteroid medication when inflammation remains significant. Injection is selective rather than automatic, and repeated injections around a tendon are approached cautiously because corticosteroids can weaken tendon tissue.

If symptoms return

Accessory navicular symptoms can recur even after a successful episode of conservative treatment. When that happens, nonsurgical measures are commonly repeated while the underlying trigger—such as footwear, activity load, flat-foot mechanics, or tendon irritation—is reassessed.

When Surgery Is Considered

Surgery is generally reserved for persistent or recurrent accessory navicular pain that continues despite an adequate course of conservative treatment or that substantially interferes with walking, work, footwear, or sports. Some specialists use a several-month conservative trial before surgery unless the clinical situation calls for a different timeline.

What surgery may involve

• Accessory navicular excision: removing the extra bone and smoothing or reshaping the prominent area.
• Kidner-type procedure: removing the accessory navicular and advancing or reattaching the posterior tibial tendon to the native navicular, often with a suture anchor.
• Posterior tibial tendon repair: repairing damaged or degenerative tendon tissue when needed.
• Flat-foot reconstruction: in selected patients with significant arch collapse or a larger structural problem, additional corrective procedures may be considered rather than treating the accessory bone alone.

The accessory navicular itself is not required for normal foot function. When surgery is appropriate, removing it does not deprive the foot of a necessary bone.

Recovery after accessory navicular surgery

These procedures are commonly performed as outpatient surgery. Some published surgeon materials describe a straightforward Kidner-type procedure as taking roughly 45 to 60 minutes, although operative time and anesthesia vary with the exact technique, tendon repair, arch mechanics, and surgical setting. The foot is then protected in a splint, cast, or boot.

Recovery protocols vary substantially. Some orthopedic programs describe roughly four to six weeks of protected weight-bearing in a boot, transition toward an athletic shoe during the following month, and return to higher-impact activity around three months. Other protocols are more protective after tendon reattachment, keeping the patient non-weight-bearing in a below-knee cast for six to eight weeks, then beginning partial weight-bearing in a rigid-soled shoe, progressing toward full weight-bearing and gentle activity around 10 weeks, and considering a cautious return to sports around four months.

Early postoperative pain can be most noticeable during the first couple of days, when elevation and strict protection are especially important. Cast changes and wound checks are often scheduled during the first few weeks. Driving depends on which foot was treated, medication use, and the ability to perform an emergency stop safely. Return to work depends heavily on job demands; some published protocols caution that returning to a physically demanding job before about 12 weeks may be unrealistic. Mild residual swelling may still be present around six months, and strength, comfort, and tissue healing can continue improving for up to a year.

Potential surgical risks

As with other foot and ankle operations, risks can include infection, delayed wound healing, prolonged swelling, a thick or sensitive scar, blood clot, persistent arch pain, tendon avulsion or incomplete tendon healing, weakness or loss of arch support, and the possibility of additional treatment or surgery. One NHS patient leaflet gives procedure-specific figures of about 2 in 100 for infection, 8 in 100 for delayed skin healing, 4 in 100 for problems related to postoperative non-compliance, 4 in 100 for prolonged swelling, and 4 in 100 for a thick or sensitive scar, and notes that about 20% of patients in its counseling material may continue to have some arch pain after surgery. Those numbers come from a single published patient protocol and are not universal complication rates; your surgeon’s own outcomes, technique, and postoperative restrictions are more relevant to your individual risk.

Prevention, Recurrence, And Long-Term Management

You cannot prevent an accessory navicular because the anatomic variant is congenital. You can, however, reduce the mechanical stress that turns a painless accessory bone into a painful one or causes symptoms to return.

• Wear supportive, properly fitting shoes with enough room so the medial prominence is not repeatedly rubbed or compressed.
• Use padding or footwear modifications when direct pressure over the bony bump is the main trigger.
• Use arch supports or custom orthotics when flat feet or posterior tibial tendon loading contribute to symptoms.
• Increase running, sports, hiking, dance, and other repetitive activity gradually rather than making sudden jumps in volume.
• Warm up appropriately and maintain calf, ankle, and foot flexibility and strength.
• Cross-train with lower-impact activities such as cycling, swimming, or selected yoga movements while a flare settles, if your clinician says those activities are appropriate and they do not reproduce pain.
• Do not repeatedly push through medial arch pain, redness, swelling, or limping.
• Have significant foot or ankle sprains evaluated when pain persists over the navicular or posterior tibial tendon.
• Return to sport gradually after immobilization or physical therapy.

The accessory navicular itself does not necessarily “get worse” with age. Many people remain asymptomatic for life. Persistent pain is the reason for treatment, not the X-ray finding by itself.

Accessory Navicular Syndrome Care In Lenexa And Greater Kansas City

Jayhawk Foot & Ankle Clinic evaluates painful inner-arch bumps, medial midfoot pain, posterior tibial tendon irritation, flat-foot mechanics, and pain that appears after a sprain or increase in sports activity for patients in Lenexa and the greater Kansas City area.

If the inside of your foot is swollen, shoes rub a painful prominence, you are limping, or arch pain keeps returning, a focused podiatry exam and X-ray can help determine whether an accessory navicular is actually causing the problem and whether the tendon or arch needs treatment too.