You may have seen people with exostosis and simply not known what it was called. It’s quite obvious when someone has this condition.

What is Exostosis?

These are bony outgrowths on the body. They are benign, meaning non-cancerous, and may occur anywhere on the body. The basic growth is the forming of new bone atop an existing bone. They are most easily noticed on the ribs, but there also may be larger growths on the elbows, hips, ankles, knees and shoulders.

article-3-pic-1Symptoms of Exostosis

Symptoms caused by exostosis tend to simply be related to their cause. If you have this disorder, your pain may range from mild to severe to debilitating. The level of pain is dependent on where the bony growths occur and their shape and size.

  • Subungual exostosis – These growths usually cause pain because they apply pressure to the nail bed and nail plate. They can also destroy the nail bed.
  • Surfer’s ear – In these cases, considered to be environmental stressors, people may develop hearing difficulties. They may have pain in the ears that the growths cause, too.
  • Retrocalcaneal exostosis – These are painful bumps, and you could also experience redness, tenderness and swelling along the prominence located on the back of the heel. The pain is worse when the patients wear shoes that rub the heel. Activity may worsen the pain, as well. There is sometimes pain where the heel bone meets the Achilles tendon.
  • Buccal exostosis – This exostosis type is generally painless
  • Metatarsal cuneiform exostosis – This type results in pain from direct pressure of shoes. Patients describe the pain as a dull ache radiating between the first and second toes.
  • Dorsal exostosis – This type can be very painful. Wearing the wrong type of shoes could cause rubbing of the growth, causing redness and swelling. If it affects the big toe, range of motion may be limited, due to the limitation of big toe extension.


Exostosis may be brought on by various things, from environmental stress to genetics.

  • No obvious cause – Sometimes bony growths can develop without clear causes.
  • Joint damage – If you have this cause, your joint strain results in developing of small deposits of bone on or near the joint.
  • Environmental stress – An example of this cause is when bone grows within the ear canal, becoming surfer’s ear. It is brought on by cold water flooding your ears frequently.
  • Buccal exostosis – This exostosis affects the jawbone. The lower jaw is less likely to be affected than the upper jaw. The bony growths may form on the outer check facing the jaw above the tooth line. It can also affect the cheek that faces the side of the affected lower jaw. These growths generally begin forming in the ages of early adulthood. Over time they will enlarge slowly.
  • Subungual exostosis – This type involves toes and fingers. The bony growths start from the back of the distal toes or fingers. This means they will be on the outermost bones on the fingers or toes.

In this type, growths occur normally occur under the nails, especially the toe nail on the big toe. They are less commonly found on fingers as compared to toes. When they do grow on fingers, they generally grow on the index and middle fingers.

The specific cause isn’t known, other than that they may occur after trauma. It is believed that constant irritation or chronic infection is also a causative factor. The growths can occur at any range of age, but there are more cases by the age of 20 and females have the growths more often than males.

  • Dorsal exostosis – This relates to distinct bumps on the top of the foot. It is sometimes called mid-foot dorsal exostosis. Shoes may be difficult to wear in this case. Open-toed shoes may work, but closed-toe shoes may cause the bony bump to rub against the shoe. It is sometimes caused by feet that roll inward when the patient walks, or in people with high arches. Trauma and injury to the general area may also cause the bump. Dorsal exostosis is sometimes similar to the growth of bunions.

When the growths affect the big toe, it can be caused by biomechanical factors that may       alter the proper alignment of the foot, or tight calf muscles that may force the arch into an     uncomfortable position. Trauma to the joint of the big toe may also be a cause.

  • Hereditary multiple exostosis (HME) – This occurs when exostoses occur randomly on the body due to a genetic condition. If your family has a history of HME, monitor children to detect the signs of any bony growths. This cause has been estimated to affect about one in 50,000 people. Most are not affected when they are born, but rather by the age of 12.
  • Retrocalcaneal exostosis – This is a bump or bone spur on the back of the heel, often involving the Achilles tendon. It affects mostly adults, rather than children, and particularly women. High heeled shoes and pumps irritate the bony growths, which is why more women are affected than men. This exostosis type can also be aggravated by Achilles tendonitis, Haglund’s deformity, inflammation, bursitis, inflamed foot pads or a tight or short Achilles tendon.
  • Osteocartilaginous exostosis – This specific cause involves bone and cartilage growth. It is sometimes called osteochondroma. It will normally appear at the end of the long bones of the body.
  • Metatarsal cuneiform exostosis – This is sometimes called saddle bone deformity. It forms on top of the foot, above the arch. It may be caused by hyper-mobility in the first metatarsal joint, where there are three bones side by side in the middle of the foot. They lead to the bases of the toes. This is usually seen between 25 and 60 years of age and is found in men and women equally.


Exostosis may be identified by a physician via an examination, x-rays and a discussion about the patient’s family medical history.


Once the physician has determined the full extent of exostosis present, and its cause, he will speak to the patient about options for treatment. The growth is allowed to remain in some cases, but if it becomes painful or particularly displeasing aesthetically, surgery is an option.

If the patient elects surgery, the physician will speak with him about the cause, so that it will not recur. If it is simply allowed to remain in place, the physician will check the growth often to ensure that no complications have occurred.

With a case of osteochondroma, the non-cancerous tumor may be left in place or removed. It all depends on how much it affects the patient’s quality of life.

If the cause is surfer’s ear, a surgeon may remove the bone from within the ear, in order to create comfort in the ear, and more importantly, to restore proper hearing.

Subungual exostosis

In this type, the surgical excision treatment has proven quite effective. The patient only has to have a local anesthesia, and after the offending growth has been removed and the underlying bone scraped clean, it should not recur.

Retrocalcaneal exostosis

For this type, the method of treatment depends on pain severity. The patient may be given a prescription for an oral NSAID or steroids, to help in lessening inflammation. Pain gels and pain patches can also be applied to the heel.  The physician may recommend heel lifts, which are wedges that go under the heel to lift it, lessening the tension on the Achilles tendons. The heel lift also helps in lifting the heel out of the shoe a bit, so the back of the shoe won’t rub on the spot that is painful.

If the pain is severe, the patient may need to have the foot immobilized within a walking boot, in order to decrease the stress and strain on the Achilles tendon. For debilitating pain, the last option is putting the foot in a cast and having the patient use crutches, so that no weight is put on the foot. Physical therapy may also be prescribed, to increase the flexibility of the Achilles tendon and lessen the inflammation of the tendons. If these methods don’t help, the patient may require surgery.

Dorsal exostosis

With exostosis of the mid-foot, the patient will wear modified footwear, to avoid pressure on the bump. For high arches and rolled-in feet, orthotic therapy may be required. Physicians may prescribe anti-inflammatory medications or recommend over the counter anti-inflammatory meds.

Injection therapy may be used to help provide joint and nerve relief. Surgery is the final option if nothing else is working, or if the pain is not bearable. When a patient suffers from dorsal exostosis of his big toe, he will need to do stretching exercises to improve the functioning of the foot. This will also correct some of the original biomechanics that caused the initial problem. Orthotics may be helpful, too. These options will all ease stress on the joint of the big toe. Again, if nothing else works, surgical treatment may be required to clean up the big toe joint.

Metatarsal cuneiform exostosis

The most successful treatment for this type of exostosis is wearing shows that do not put any pressure on bony bumps. These may include sandals, low cut dress shoes or flip-flops. Some patients have also had success with using a tongue pad. This creates a small area under the tongue of the shoe that relieves excess pressure on a bump.

If this exostosis type is serious enough that surgery is needed, it is done in a hospital or surgery center under sedation and a local anesthesia or a general anesthetic. After the surgery, patients can put weight on their foot. It takes about four to six weeks before they can successfully return to their normal activities.


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