[The shoulder in basic calcium phosphate microcrystal deposit disease].

Area of Science:

• Radiology
• Orthopedics
• Rheumatology

Background:

• Basic calcium phosphate (BCP) crystal deposition is a common cause of periarticular collections.
• These deposits are most frequently observed in the shoulder but can occur in other joints like the wrist, hand, foot, elbow, and hip.
• The radiographic appearance of BCP deposits can evolve over time.

Purpose of the Study:

• To describe the radiographic findings associated with basic calcium phosphate crystal deposition in various articular sites.
• To illustrate the diverse patterns and evolution of BCP deposits on imaging.
• To correlate radiographic features with the location of deposits within soft tissues.

Main Methods:

• Review of radiographic findings in patients with confirmed basic calcium phosphate crystal deposition.
• Analysis of the location, size, configuration, and evolution of calcifications.
• Correlation of imaging findings with anatomical location (tendons, bursae, soft tissues).

Main Results:

• BCP crystal deposition leads to periarticular collections with characteristic radiographic findings, predominantly in the shoulder.
• Deposits initially appear cloudlike and can evolve into linear, triangular, or circular patterns.
• Adjacent bone may show normal findings, osteoporosis, cystic lesions, or reactive sclerosis.

Conclusions:

• Radiographic appearance of BCP deposits is variable and depends on their location within the rotator cuff, bursae, and soft tissues.
• Understanding these varied radiographic patterns is crucial for accurate diagnosis.
• BCP deposition should be considered in the differential diagnosis of periarticular calcifications.