Shoulder Pain. Shoulder Anatomy: Bony Anatomy. Humerus Scapula Glenoid Acromion Coracoid Scapular body Clavicle Sternum. Shoulder Anatomy: Joints. Glenohumeral Acromioclavicular. Sternoclavicular Scapulothoracic articulation. Glenohumeral Joint. Most common dislocated joint
The supraspinatustendon is the most studied tendon of the rotator cuff because it is the most commonly affected tendon in rotator cuff pathology.
The supraspinatus tendon is relatively thick as it courses between the superior aspect of the humeral head and the inferior aspect of the acromion.
Normally, a well-defined space exists between the tendon and the acromion:
thesubacromial space. This space is occupied by the subacromial bursa. Laterally, the space and the bursa generally extend beyond the lateral aspect of the acromion underneath the deltoid muscle .
The causes of shoulder pain are numerous.
II. Chronic shoulder pain often has a less obvious cause. Common causes include:
Shoulder Pain:Physical Examination
Patients who present with a painful stiff shoulder are frequently diagnosed with “frozen shoulder.” does not denote a specific pathology. Rather, it applies to what he described as “many conditions which cause spasm of the short rotators or adhesions about the joint or bursae.”
Adhesive capsulitisis a specific pathologic entity in which chronic inflammation of the capsule subsynovial layer produces capsular thickening, fibrosis, and adherence of the capsule to itself and to the anatomic neck of the humerus. The contracted, adherent capsule causes pain, especially when it is stretched suddenly, and produces a mechanical restraint to motion.
Many conditions can produce symptoms similar to those of adhesive capsulitis, these include:
In these conditions, motion loss is typically multifactorial rather than the result of isolated capsular restriction.
Adhesive capsulitis is characterized by :
The fibrotic capsule adheres to itself and to the anatomic neck of the humerus. There is minimal synovial fluid in the joint, and overall joint volume is diminished.
Normal shoulder joint volumetric capacity is 28 to 35 mL of injected fluid,whereas in adhesive capsulitis, the joint accepts only 5 to 10 mL.
Four stages of disease have been described The disease progresses from capsular inflammation to fibrosis .
In stage 4, the chronic stage, adhesions are fully mature, and motion is severely reduced. Patients may have painless, limited range of motion in stage 4, but pain occurs when the arm is suddenly moved beyond the limits of the scarred capsule.
Patients typically present with pain of insidious onset of several months duration. The onset of symptoms tends to be more gradual than in other shoulder conditions. Pain is commonly referred to the origin of the deltoid. Night pain is common, and patients typically cannot sleep on the affected side.