How To Repair Calcaneal Step Deformities
Distal posterior heel pain is a deformity we see quite often. It masquerades as chronic Achilles tendinitis, when in fact a calcaneal step (aka retrocalcaneal exostoses) is present at the Achilles insertion. You must also clinically differentiate it from adjacent problems, such as Haglund’s deformity, retrocalcaneal bursitis and intra-Achilles tendon tear. Often, these problems may be concurrent, however, you must treat the calcaneal exostoses for complete cessation of pain. Keep in mind that retrocalcaneal exostoses are most symptomatic in active individuals over 30.
On inspection, you will usually note a red and irritated area across the entire posterior heel, not just the posterior superior lateral aspect, which is most commonly associated with Haglund’s deformity. Lateral X-rays in the weight bearing position reveal the calcaneal step deformity at the area of the Achilles insertion, located at the distal two-thirds of the posterior heel. You may also see thickening of the Achilles near its insertion, pain during range of motion, and crepitation due to synovitis. Since you may also see some of these findings with Achilles microtears and chronic Achilles tendinitis, it is necessary to palpate in addition to getting an X-ray.
Listening to your patient’s complaints often helps to differentiate the distal posterior heel spur from a Haglund’s deformity, which is usually bothersome when it rubs against the hard counter of a shoe. Complaints of morning pain, also known as post static dyskinesia, are more indicative of chronic Achilles tendinitis, which can be precipitated by a calcaneal step deformity.
Know The Causes Of Calcaneal Step Deformities
These deformities may be due to a longer horizontal calcaneus, excessive frontal plane motions of the heel and tight calves. Tension from tight calves and excessive frontal plane motions of the heel are exaggerated on softer surfaces and with increased activities. This causes abnormal tension at the Achilles insertion with subsequent reactive bone formation and hyperostosis.
Subsequently, the calcifications can cause irritation, which leads to inflammation and possible microtears with resultant healing and fibrosis. Furthermore, the excessive motions may create cumulative stresses or microtrauma, which result in degenerative changes within the Achilles. It typically takes years for the hyperostosis to develop, which you most commonly see in active individuals during middle or older ages. After reading about the pathomechanics leading to the progression of the calcaneal step deformity, you can appreciate how similar it can be to the development of plantar calcaneal heel spurs and patellar tendinitis with insertional calcification.
Assessing The Radiographic Findings
The calcaneal step deformity is present at the insertion of the Achilles tendon. Sometimes, the posterior calcaneal spurring or exostoses may be a separate ossicle or it may fracture off and appear fragmented. Since the remaining portion of the calcaneus often obscures these, it is helpful to take several lateral X-rays of the heel with the foot angled approximately 10, 15 and 20 degrees away from the plate. I find these views more helpful than the axial calcaneal views. Keep in mind that calcaneal step deformities are often incidental findings on X-rays of patients who have other foot disorders.
Recent literature suggests the calcaneal step deformity may not be within the Achilles tendon, but does irritate the overlying Achilles tendon. Getting an MRI or diagnostic ultrasound may be useful for making this determination.1 Checking the X-rays for other joint pathology or insertional calcifications should prompt you to test for any other arthritities, such as rheumatoid, psoriatic, gouty or ankylosing spondylitis-type arthritic disorders.
When it comes to conservative treatment for retrocalcaneal exostoses, focus on resolving the cause of the problem. You can use the Silfverskiold test to clinically diagnose a tight calf. If indicated, put the patient on a stretching regimen, including the wall push, slant board or Pro Stretch device.