An exostosis is an overgrowth of bone and subungual means under the nail. Subungual exostosis is a benign bony growth that develops underneath the toenail, most often near the tip of the big toe.
As the growth enlarges, it can push against the nail, causing pain, swelling, and changes in the appearance of the toenail.
Although the growth is not cancerous, it can become increasingly uncomfortable and interfere with walking and wearing shoes.
Causes
The exact cause of subungual exostosis is not fully understood. Repeated irritation, previous trauma to the toe, and sometimes infection may contribute to its development. A family history of similar bone growths may also play a role in some cases.
Symptoms
Symptoms usually develop gradually and may include pain or tenderness at the tip of the toe, a noticeable lump beneath the toenail, and pressure when wearing shoes or walking.
As the growth gets larger, it may push the nail upward, change its shape, or cause part of the nail to separate from the nail bed. The nail may also develop a white or yellowish discoloration.
Diagnosis
Your doctor will examine the toe and ask about your symptoms and any history of injury. Because this condition can resemble a wart, fungal nail infection, or another type of growth, imaging is important.
X-rays are typically used to identify the bony growth and determine its size and location. An MRI may occasionally be recommended if additional information about the surrounding soft tissues is needed.
Treatment Options
Treatment depends on the size of the growth and how much pain or nail damage it causes.
For mild symptoms, cushioning, changes in footwear, and anti-inflammatory medication may help reduce discomfort. However, these measures do not remove the underlying bone growth.
When the growth causes persistent pain, pressure, or nail deformity, surgery is usually the most effective treatment.
Subungual Exostectomy Surgery
Subungual exostectomy involves surgically removing the extra bone beneath the toenail. The goal is to remove the growth completely while protecting the nail bed and surrounding tissues.
Your surgeon makes an incision to access the growth and carefully removes the abnormal bone, typically down to normal bone tissue. Preserving the nail bed is important because damage to this area can affect how the nail grows back.
The procedure is generally successful in relieving pressure and pain. Thorough removal also helps reduce the chance of the growth returning.
Recovery After Surgery
After surgery, the toe is protected with a dressing and a surgical shoe or other protective footwear. You may need to limit pressure on the toe while the incision heals.
Recovery depends on the size and location of the growth and the extent of the procedure. Follow-up appointments allow your surgeon to check the incision, monitor nail healing, and make sure the growth has been adequately removed. Your surgeon will provide instructions on when to return to regular shoes and activities.
Risks and Complications
As with any surgery, complications are possible. These include infection, delayed wound healing, and recurrence if some of the abnormal bone remains.
One important concern is abnormal nail growth, also called onychodystrophy. This can happen if the nail bed is damaged during surgery. Careful surgical technique helps protect the nail and reduce this risk.
Long-Term Outlook
The outlook after subungual exostectomy is generally very good. Most patients experience significant pain relief and can return to normal activities after healing. Recurrence is uncommon when the growth is completely removed, although continued follow-up is important.
When to See a Specialist
If you notice a painful lump beneath your toenail, persistent pressure, or changes in the shape or attachment of the nail, have your toe evaluated by a foot and ankle specialist. Early diagnosis can help prevent worsening discomfort and nail damage.
Insurance and Cost
Subungual exostectomy at Complete Orthopedics is covered by Medicare and most major insurance carriers, including Aetna, Anthem BCBS, Cigna, Empire BCBS, and UnitedHealthcare. We also work with most workers’ compensation and no-fault insurance plans.
Your out-of-pocket cost depends on your insurance plan, deductible, and coverage requirements. Call our billing team at (631) 981-2663 before scheduling to verify your benefits and discuss expected costs.
For more information, visit our Insurance Information page.
The content on this page has been authored, edited, or approved by the doctors below, and was last reviewed for accuracy on November 12, 2026.
