Tendinitis calcarea

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).

Epidemiology

Typically this condition affects middle-aged patients between the ages of 30 and 60, with a slight predilection for women .

Clinical presentation

The condition passes through four stages :

  • pre-calcific
    • asymptomatic
    • fibrocartilaginous metaplasia (see below)
  • calcific or formative
    • symptoms are variable from none to pain on movement
  • resorptive
    • most symptomatic
    • pain due to extravasation of calcium hydroxyapatite into adjacent tissues, especially subacromial bursa, causing calcific bursitis
    • pain typically lasts two weeks
  • post-calcific
    • variable symptomatology
    • some restriction of movement common
    • may last months
  • Pathology

    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 .

    Location

    This condition most frequently affects the rotator cuff of the shoulder .

    However, the condition may occur anywhere in the body with the hip and knee being the other most common locations .

    Radiographic features

    Plain radiograph

    Calcific deposits are usually visualized as homogeneous hyperdensity with variable morphology, but typically globular/amorphous with smooth or ill-defined margins.

    Ultrasound

    Features of calcific tendinitis on ultrasound may include :

    • a curvilinear/ovoid calcification with acoustic shadowing
    • capsular soft tissue swelling
    MRI
    • T1
      • hypointense homogeneous signal
      • adjacent tendon may be thickened
      • some enhancement surrounding deposit may be seen
    • T2
      • 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

    Differential diagnosis

    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