Abstract

Calcific tendinitis is a form of tendinitis, a disorder characterized by deposits of hydroxyapatite (a crystalline calcium phosphate) in any tendon of the body, but most commonly in the tendons of the rotator cuff (shoulder), causing pain and inflammation. The condition is related to and may cause adhesive capsulitis ("frozen shoulder").

Signs and symptoms

Pain is often aggravated by elevation of the arm above shoulder level or by lying on the shoulder. Pain may awaken the patient from sleep. Other complaints may be stiffness, snapping, catching, or weakness of the shoulder.

Cause

Three main theories have emerged in an attempt to explain the mechanisms involved in tendon calcification. The first theory is the theory of reactive calcification and involves an active cell-mediated process, usually followed by spontaneous resorption by phagocytosing multinucleated cells showing a typical osteoclast phenotype. The second theory suggests that calcium deposits are formed by a process resembling endochondral ossification. The mechanism involves regional hypoxia, which transforms tenocytes into chondrocytes. The third theory involves ectopic bone formation from metaplasia of mesenchymal stem cells normally present in tendon tissue into osteogenic cells. As no single theory is satisfactory to explain all cases, calcific tendinopathy is currently believed to be multifactorial.

Diagnosis

The calcific deposits are visible on X-ray as discrete lumps or cloudy areas. The deposits look cloudy on X-ray if they are in the process of reabsorption, and this is also when they cause the most pain. The deposits are crystalline when in their resting phase and like toothpaste in the reabsorptive phase. However, poor correlation exists between the appearance of a calcific deposit on plain X-rays and its consistency on needling. Ultrasound is also useful to depict calcific deposits and closely correlates with the stage of disease.

Treatment

Usually it improves without specific treatment. Treatments of calcific tendinitis may include physiotherapy, NSAIDs, or steroid injections. If these do not work extracorporeal shock wave therapy or surgery may be considered.

Treatment | Medications

Analgesics and nonsteroidal anti-inflammatory drugs (NSAIDs) are useful to a limited extent. Corticosteroid injections may be useful when the shoulder is acutely inflamed but otherwise are not generally useful except for the temporary relief of pain.

Treatment | Physical therapy

Electroanalgesia, ice therapy, and heat offer symptomatic relief. The benefit of ultrasound in calcific tendinitis is debated; most studies are negative but a study by Ebenbichler et al. (1999) showed resolution of deposits and clinical improvement.

Improving the biomechanics of the shoulder will reduce the tension on the fault muscles allowing a decrease in symptoms. Improved biomechanics are thought to reduce the amount of calcification that occurs especially in the case on supraspinatus where it can be caused from repetitive compression against the acromion.

Treatment | Extracorporeal shock wave therapy

In those with calcific tendinitis of the shoulder high energy extracorporeal shock-wave therapy (which uses sound waves) can be useful. It is not useful in other types of tendinitis. This procedure may be known as .

Treatment | Surgery

Removing the deposit/s either with open shoulder surgery or arthroscopic surgery are both difficult operations, but with high success rates (around 90%). About 10% require re-operation. If the deposit is large, then frequently the patient will require a rotator cuff repair to fix the defect left in the tendon when the deposit is removed or to reattach the tendon to the bone if the deposit was at the tendon insertion into the bone.

Treatment | Other

In studies, acetic acid iontophoresis combined with ultrasound provided no better clinical results or shrinkage of the calcific deposits than did no treatment. Platelet-rich plasma (PRP) is blood plasma that has been enriched with platelets. It has not been well studied in calcific tendinitis.

Under local anesthetic, the calcific deposits can be mechanically broken up by puncturing them repeatedly with a needle and then aspirating the calcific material with the help of a sluice of saline. Ultrasound can be used to help localize the deposit and to visualize the needle entering the deposit in real time. Available evidence does not suggest a benefit over usual treatments.