Calcific tendinitis
| Calcific tendinitis | |
|---|---|
| Synonyms | calcific/calcifying/calcified/calcareous tendinitis/tendonitis/tendinopathy, tendinosis calcarea, hydroxyapatite deposition disease (HADD), calcific periarthritis |
 |
|
| A plain X ray of the shoulder showing calcific tendinitis | |
| Classification and external resources | |
| Specialty | rheumatology |
| ICD-10 | M65.2, M75.3 |
| ICD-9-CM | 727.82 |
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").
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.
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.
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.
...
Wikipedia