WHAT IS A RETROCALCANEAL EXOSTOSIS?
Extra bone formation (exostosis) on the back (reho) of the heel bone (calcaneous) is called a retrocalcaneal exostosis. Some people will also call this a heel spur, different from a spur found on the bottom of the heel. The extra bone develops on the back of the heel bone and within the Achilles tendon. The formation of this exostosis has a direct connection with the Achilles tendon, its length and elasticity.
The Achilles tendon is a strong, thick, and important structure that functions to bring the ankle upward and the foot downward and propel the body forward in gait. Thousands of fibrous brands of tissue bind together form the dense Achilles. The calf muscle (gastrocnemius) becomes the Achilles tendon about midway in the lower leg. The tendon travels down the back of the leg, crosses the ankle, and attaches to the top and back of the heel bone (calcaneous). The Achilles tendon acts as a “rubber band” that stretches back and forth with each step.
WHAT ARE THE SYMPTOMS OF A RETROCALCANEAL EXOSTOSIS?
Patients will complaint of a deep achy and sharp knife-like pain on the back of the heel. The pain is more pronounced with each step when walking and any activities. There can even be some pain at rest. There is often a visible mass of extra bone on the back of the heel. Some days the bump will look larger if there is irritation and swelling of the bursa (bursitis). Any direct pressure over the bone will be significantly painful. Most patients will complain of substantial pain when taking their first few steps out of bed or after sitting for some time, and then walking. This pain can ease when there is more walking, and then increase again towards the end of the day.
Most find that being barefoot, using flat shoes and shoes without support lend to more pain because the pull of the Achilles tendon on the bone is at its maximum. Certain shoes may cause more friction of the skin over the bone leading to more pain. The pain usually will worsen gradually over time. In the event of trauma to the heel or a sudden movement and pull of the Achilles, the bone spur can fracture causing even more pain. With continued growth of the bone, the Achilles tendon can also become irritated leading to an Achilles tendonitis and eventually Achilles tendonosis.
WHAT CAUSES A RETROCALCANEAL EXOSTOSIS?
The bones in the body stay dense and strong due to the stresses placed upon them. Disuse of the bone leads to weak bone and osteoporosis. over stimulation of bone leads to extra bone growth. The constant tugging of a short Achilles tendon on its attachment to the back of the heel bone (calcaneous) stimulates extra bone formation. With the continued bone growth there is more friction against the extra bone from the shoes, leading to even more stimulation, leading to even more bone growth. Patients born with a short tendon (toe walkers) or develop shortening of the tendon/muscle complex (equinus) over time have a higher change of developing a etrocalcaneal exostosis. Examples of those that risk shortening their tendon are those that wear high heel shoes for extended periods of time and ballet dancers that go onto point. Those patients with a high arch (pes cavus) have a higher chance of developing the spur formation due to the extra pull of the Achilles tendon.
HOW IS A RETROCALCANEAL EXOSTOSIS DIAGNOSED?
Diagnosis is achieved by the clinical examination, radiographs (x-rays), and possibly a diagnostic ultrasound or MRI of the patient. Dr. Heath will listen to your complaints, symptoms, and goals. The examination involves a hands-on analysis of the patient’s foot and ankle and an evaluation of their gait. There will be a special examination of the Achilles tendon and its muscle to determine and underlying cause and any shortening of the tendon. Radiographs (x-rays) of the ankle will be obtained in the office and reviewed with the patient. The films evaluate the heel bone for the extent of the heel spur and extra bone. In some cases, a CT maybe obtained to evaluate the heel bone further.
Dr. Heath may evaluate the tendon using a state-of-the-art diagnostic ultrasound. This examination will show the thickness and swelling and any amount of damage and tearing of the tendon that may be associated with the exostosis.
An MRI may be ordered to evaluate the tendon directly in 3 dimensions. It may also be needed for those patients with suspected partial or full Achilles tendon rupture.
CONSERVATIVE TREATMENT FOR A RETROCALCANEAL EXOSTOSIS:
Conservative treatment for retrocalcaneal exostosis is limited. These treatments rely on their ability to decrease pain, reduce inflammation, stop the micro tearing of the tendon, and stretch the tendon. Dr. Heath may recommend a strict 2-4 weeks initial therapy protocol. Reduction of the inflammation and pain can be achieved by treating the area with a daily regimen of ice therapy and the use of anti-inflammatory medications. A period of rest may be needed in order to reduce the constant stretching of the tendon and pressure on the exostosis while it is trying to heal. Heel lifts can be placed in the shoes to place some slack on the Achilles. In most cases a walking boot to restrict the pull of the tendon on the bone will be recommended. The patient will be educated on a stretching regiment for the calf and the Achilles tendon. Stretching of the muscle/tendon complex is very important in order to elongate the complex allow the tendon to be more elastic and reduce the occurrence of the micro tears. These stretching exercises will be especially important in the mornings before getting out of bed or after a period of rest. Dr. Heath may recommend a course of visits to a physical therapist.
CUSTOM MOLDED ORTHOTICS
Custom molded orthotics (insoles) are an integral part of healing and maintaining the integrity of the Achilles and redirecting the pull of the tendon and the position of the extra bone formation. The pull of the tendon on the heel bone plays an important role in the support of the arch of the foot. When the tendon is damaged and irritated, the arch and the heel will need to be supported by a custom orthotics, to reduce the forces placed on the tendon while walking and increased activity. The orthotics control the amount of motion through the heel during gait and take off some of the strain the tendon would normally incur. These treatments have a high chance of failure because they do not reduce the extra bone itself. Most of the pain is caused by the extra bone formation, at some point, this bone must be removed to alleviate pain.
Cortisone (STEROID) INJECTIONS:
Dr. Heath does NOT recommend cortisone injections for the retrocalcaneal exostosis. Steroid injections have many positive applications for treatment of foot and ankle problems. However, the Achilles tendon can weaken when injected with cortisone.
SURGICAL TREATMENT FOR A RETROCALCANEAL EXOSTOSIS:
Dr. Heath will always recommend and attempt conservative treatment when appropriate. However, when a retrocalcaneal exostosis becomes chronically painful and activity is limited, surgical repair may be indicated.
IS RETROCALCANEAL EXOSTOSIS SURGERY PAINFUL?
Considering surgery can be intimidating. When the skin and the soft tissues are handled with care and focus, most patients experience controllable pain after surgery and decreases quickly throughout the recovery period. Dr. Heath takes great care and focus to minimize the chance of post-operative pain. The goal of retrocalcaneal exostosis surgery is to remove the extra bone, remove any scar tissue and damaged tendon, repair tendon tissue, alleviate pain, allow a return to normal shoes, and help to allow a return to desired activities. Dr. Heath performs the procedures in an outpatient setting at a state of the art facility.
The objective of this surgery is to remove the extra bone and repair the tendon as needed. An incision is made into the skin on the back of the Achilles tendon and heel bone. Once the tendon is exposed, an incision is made just next to the tendon. The portion of the damaged tendon, are removed along with any scar tissue, and any extra bulk of the tendon. Any bone fragments or calcifications that may be in the tendon are removed. The bone spur is also removed. If the tendon is too short an extra step may be taken to lengthen the tendon to reduce the chance of recurrence of a new spur. Using specialized stitches and dissolvable anchors, the opened tendon is then repaired and placed back onto the heel bone. The skin is then closed. An injection of PRP (platelet Rich Plasma) is injected to promote healing of the tendon at the surgical site. The procedure will require some time in a special boot or cast and a steerable knee walker(scooter), traditional walker or crutches, which ever works best for your specific situation, with non weight bearing for three weeks in a boot then weight bearing in a boot for 3 more weeks.