Calcific tendinitis (or calcific tendonitis) is a self-limiting condition due to the deposition of calcium hydroxyapatite within tendons, usually of the rotator cuff. It is a common presentation of the hydroxyapatite crystal deposition disease (HADD).
Typically this condition affects middle-aged patients between the ages of 30 and 60, with a slight predilection for women .
The condition passes through four stages :
- fibrocartilaginous metaplasia (see below)
- symptoms are variable from none to pain on movement
- variable symptomatology
- some restriction of movement common
- may last months
Calcific tendinitis results from the deposition of calcium hydroxyapatite within the substance of a tendon and is thought to be due to decreased oxygen tension, leading to fibrocartilaginous metaplasia and secondary mineralization .
This condition most frequently affects the rotator cuff of the shoulder .
- supraspinatus: 80%
- infraspinatus: 15%
- subscapularis: 5%
- periarticular soft tissues in addition to tendons
However, the condition may occur anywhere in the body with the hip and knee being the other most common locations .
Calcific deposits are usually visualized as homogeneous hyperdensity with variable morphology, but typically globular/amorphous with smooth or ill-defined margins.
Features of calcific tendinitis on ultrasound may include :
- a curvilinear/ovoid calcification with acoustic shadowing
- capsular soft tissue swelling
- hypointense homogeneous signal
- adjacent tendon may be thickened
- some enhancement surrounding deposit may be seen
- hypointense calcium deposits
- hyperintense signal may be present peripherally due to edema
- hyperintense subacromial-subdeltoid bursal fluid
- T2*: calcifications may bloom
Treatment and prognosis
Controversial and difficult to measure due to the inherent variability of the symptoms and the self-limiting nature of the disease. Potential treatments include :
- oral analgesic/anti-inflammatory medication
- subacromial local anesthetic/steroid injection
- aspiration of mineralized material
- ultrasound therapy
In the shoulder consider:
- incidental calcification: seen in 2.5-20% of 'normal' healthy shoulders
- degenerative calcification
- seen in previously torn tendons
- generally smaller
- slightly older individuals
- loose bodies
- associated chondral defect
- associated secondary osteoarthritis