Shoulder capsular pattern, how severe is it?

The Diagnostic Relevance of a Capsular Pattern in the Shoulder

In orthopaedic medicine, the concept of a capsular pattern is crucial for identifying joint pathologies, for example in the shoulder. A capsular pattern refers to a specific, predictable limitation of joint movement that occurs when the entire joint capsule is affected, such as in adhesive capsulitis (frozen shoulder) or chronic synovitis.

For the glenohumeral joint, the classic capsular pattern presents with a distinct order of motion restriction:
External rotation is most limited, followed by abduction, and finally internal rotation (ER > ABD > IR). This pattern reflects the biomechanical structure of the joint capsule and its differential tension during various movements.

Recognizing this pattern has strong diagnostic value:

• It points toward intra-articular pathology, especially when there's no history of trauma.
• It helps differentiate between capsular involvement and other sources of shoulder dysfunction, such as rotator cuff lesions, isolated tendinosis, or subacromial pain syndrome, which do not typically follow a capsular pattern.
• It aids in clinical decision-making, guiding conservative versus more invasive treatment approaches.

In summary, identifying a capsular pattern in the shoulder is a key element in musculoskeletal assessment. It not only narrows the differential diagnosis but also strengthens clinical reasoning and supports targeted management strategies.