How To Conquer Achilles Insertional Calcific Tendinosis
Achilles insertional calcific tendinosis can cause posterior heel pain in both active and sedentary patients, and can be aggravated by activity or footwear. Accordingly, this author reviews keys to diagnosis, offers insights on conservative and surgical treatment, and provides two illuminating case studies.
Posterior heel pain is a common cause of pain and disability affecting individuals ranging from the high level athlete to the obese and sedentary. In each patient population afflicted with this condition, there are different challenges related to the treatment and the expectations of the individual.
There are a number of different clinical entities responsible for posterior heel pain including Achilles insertional calcific tendinosis. This disorder is characterized by the presence of a calcified mass in the distal Achilles tendon at its insertion site onto the posterior calcaneus. Localized erythema and edema may be present along with an inflamed retrocalcaneal bursal sac. Individuals with this disorder complain of stiffness in the Achilles tendon following a period of inactivity or first thing in the morning when they are first ambulating. Activities such as running or jumping will aggravate the condition and often force the participant to stop.
Certain types of footwear will also be problematic. Dress shoes with a stiff heel counter can rub on the area, causing irritation and blister formation. Other types of footwear for sports such as ice hockey skates or ski boots may cause significant problems due to the tight and stiff heel counter. However, patients can often modify these to accommodate the protuberance.1
Stress placed on the Achilles tendon during loading results in the initial microscopic intratendinous changes that produce microtearing of the tendons, leading to localized collagen degeneration with subsequent mucinoid degeneration or fibrosis.2 The paratenon can be involved in the process and become chronically inflamed, thickened and fibrotic.3 Over time, differentiation of tendons can result in the development of a calcified mass within the substance of the Achilles tendon. In other cases, it would appear that a posterior calcaneal spur has separated or fractured from the calcaneus.
Evaluating the Achilles tendon, researchers conducted a study to ascertain whether tendon samples harvested from patients with calcific insertional Achilles tendinopathy showed features of a failed healing response.4 The study also determined whether these tenocytes had produced abnormal quantities of type II collagen in that area. The study authors harvested tendon samples from eight otherwise healthy male individuals (average age 47.5 ± 8.4 years, ranging from 38 to 60) who underwent surgery for calcific insertional Achilles tendinopathy and from nine male patients who died of cardiovascular events (mean age 63.1 ± 10.9 years) while in the hospital. The researchers obtained histochemical, immunohistochemical and immunocytochemical evaluation of the tendons.
The results of the study demonstrated that the tenocytes from tendons of patients with calcific insertional Achilles tendinopathy exhibited chondral metaplasia and produced abnormally high quantities of collagen type II and III.4 The authors concluded that the altered production of collagen may be one reason for the histopathological alterations described in the study. Areas of calcific insertional Achilles tendinopathy have been subject to abnormal loads. These tendons may be less resistant to tensile forces. Further studies should investigate why some tendons undergo these changes.
Examination of the patient may reveal an ankle equinus, which may also be a predisposing factor in the development of the condition. One would identify a solid mass or bump in the posterior heel. Pain is typically present with side to side compression of the mass.