By: Terry R. Yochum, DC, DACBR, Fellow, ACCR, and Chad J. Maola, DC
This adult male patient complains of chronic shoulder pain. He had multiple shoulder dislocations when he was younger playing football. Do you see something unusual here?
Severe glenohumeral degenerative joint disease (DJD) with superior displacement of the humerus as a result of rotator cuff tear. Note the severe narrowing of the space between the humeral head and the distal clavicle and the acromion process — a radiographic sign of rotator cuff tear.
Degenerative joint disease (DJD) is a progressive, non-inflammatory disease characterized by degenerative pathologic changes in articular cartilage and its related components. Typically, the small joints of the hands and larger weightbearing joints are involved. The exact etiology of DJD is essentially unknown, although the pathogenetic sequence of changes is well documented. As a clinical entity it is by far the most commonly encountered pathologic joint affliction. Although the radiographic features are distinctive and often pronounced, a great disparity exists in the observed clinical and radiologic findings in any given patient.
Few orthopedic and radiographic abnormalities have enjoyed such a wide variation in nomenclature as degenerative joint disease. Tarnopolsky collected 54 terms applied to this disease.1 The most common terms include osteoarthritis, osteoarthrosis, degenerative arthritis, degenerative arthrosis, and degenerative joint disease.
Osteoarthritis has been the term traditionally identified with degenerative joint disease; however, “osteoarthritis” is no longer considered accurately descriptive. In reality it represents a misnomer since the suffix “itis” implies an inflammatory condition, which is not substantiated by the observed pathologic alterations. Consequently, degenerative joint disease (DJD) has gained the most universal acceptance in the literature.
Degenerative changes in the acromioclavicular joint are far more common than in the glenohumeral joint. Consequently, any signs of degenerative joint disease in the glenohumeral joint should arouse suspicion of previous significant trauma or an underlying cartilage disease such as calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, ochronosis, or acromegaly.
Acromioclavicular joint. Loss of joint space, sclerosis, and osteophyte formation are characteristic. Small subchondral cysts may be observed in the distal clavicle.
Glenohumeral joint. Articular changes consist of a non-uniform loss of joint space, sclerosis, and osteophyte formation, particularly at the inferior humeral head. Associated subchondral cysts may be seen at the articular surface, although these are usually very small.
Rotator cuff degeneration may manifest as small cyst formation in the tuberosities. Rotator cuff disruption is characterized by a superior migration of the humerus in relation to the glenoid cavity, due to the unopposed action of the deltoid muscle. Erosion with sclerosis of the inferior surface of the acromion usually accompanies this superior humeral displacement. Definitive diagnosis of a torn rotator cuff can be achieved with arthrography, ultrasound or MRI.
Calcific tendinitis and bursitis. Commonly, these are seen radiographically in both symptomatic and asymptomatic shoulders. Calcification is the sequela of degenerative tendinitis at the bony attachments of the tendon. Frequently, there is bilateral involvement simultaneously.
The most common location for calcification is the supraspinatus tendon insertion at the greater tuberosity, best seen on the external rotation view. The second most common site is calcification in the subacromial bursa, which is seen below the acromion and above the humeral head. Other tendons that may develop calcification are the infraspinatus, teres minor and subscapularis.
1. Yochum TR, Rowe LJ. Essentials of Skeletal Radiology, 3rd ed. Baltimore: Williams & Wilkins, 2005:513.