Chronic shoulder pain: Part I. evaluation and diagnosis

/Home/Chiropractic Treatment for Low Back Pain

Chronic shoulder pain: Part I. evaluation and diagnosis
Feb 15, 2008
Kelton M. Burbank, J. Herbert Stevenson, Gregory R. Czarnecki, Justin Dorfman
American Family Physician,

Shoulder pain is defined as chronic when it has been present for longer than six months. Common conditions that can result in chronic shoulder pain include rotator cuff disorders, adhesive capsulitis, shoulder instability, and shoulder arthritis. Rotator cuff disorders include tendinopathy, partial tears, and complete tears. A clinical decision rule that is helpful in the diagnosis of rotator cuff tears includes pain with overhead activity, weakness on empty can and external rotation tests, and a positive impingement sign. Adhesive capsulitis can be associated with diabetes and thyroid disorders. Clinical presentation includes diffuse shoulder pain with restricted passive range of motion on examination. Acromioclavicular osteoarthritis presents with superior shoulder pain, acromioclavicular joint tenderness, and a painful cross-body adduction test. In patients who are older than 50 years, glenohumeral osteoarthritis usually presents as gradual pain and loss of motion. In patients younger than 40 years, glenohumeral instability generally presents with a history of dislocation or subluxation events. Positive apprehension and relocation are consistent with the diagnosis. Imaging studies, indicated when diagnosis remains unclear or management would be altered, include plain radiographs, magnetic resonance imaging, ultrasonography, and computed tomography scans. Plain radiographs may help diagnose massive rotator cuff tears, shoulder instability, and shoulder arthritis. Magnetic resonance imaging and ultrasonography are preferred for rotator cuff disorders. For shoulder instability, magnetic resonance imaging arthrogram is preferred over magnetic resonance imaging.

Shoulder pain is responsible for approximately 16 percent of all musculoskeletal complaints, (1) with a yearly incidence of 15 new episodes per 1,000 patients seen in the primary care setting. (2) Part I of this two-part article will provide the primary care physician with a simple, effective approach to the diagnosis of chronic shoulder disorders such as rotator cuff pathology, adhesive capsulitis, acromioclavicular osteoarthritis, glenohumeral osteoarthritis, and instability. Part II, which appears in this issue of AFP (p. 493), discusses the treatments of chronic shoulder pain that are consistent with recent evidence-based guidelines. (3,4) Shoulder pain is defined as chronic when it has been present for longer than six months, regardless of whether the patient has previously sought treatment. It can be divided into six diagnostic categories: (1) rotator cuff disorders, including tendinosis, full or partial thickness tears, or calcific tendinitis; (2) adhesive capsulitis; (3) glenohumeral osteoarthritis; (4) glenohumeral instability; (5) acromioclavicular joint pathology; and (6) other chronic pain, including less common shoulder problems and non-shoulder problems.

Clinical Diagnosis

MEDICAL HISTORY

Table 1 (5-11) summarizes the history and potentially associated shoulder conditions for patients with chronic shoulder pain. The age of the patient is an important initial consideration. Patients younger than 40 years are more likely to present with shoulder instability or mild rotator cuff disease (impingement, tendinopathy), whereas patients older than 40 years are at an increased risk for advanced, chronic rotator cuff disease (partial or complete tear), adhesive capsulitis, or glenohumeral osteoarthritis. (3-5, 12-14)

The occupational and recreational interests of the patient are also important in the evaluation of shoulder pain. A history of collision sports or weight lifting might make instability or acromioclavicular osteoarthritis more likely, whereas overhead sports or work activities might make rotator cuff pathology more likely.

The location of the pain can be helpful for diagnosis. Anterior-superior pain often can be localized to the acromioclavicular joint, whereas lateral deltoid pain is often correlated with rotator cuff pathology. Neck pain and radiating symptoms should be explored because cervical pathology can mimic shoulder pain. Typically, pain that radiates past the elbow to the hand is not related to shoulder pathology. However, it is not uncommon to have pain that radiates into the neck because the trapezius muscle often spasms in patients with underlying chronic shoulder pathology. The presence of both is more likely to be related to cervical pathology. Dull, achy night pain is often associated with rotator cuff tears or severe glenohumeral osteoarthritis.

Previous treatments and factors that aggravate or alleviate the pain can be important clues to the diagnosis. Night pain from sleeping on the affected shoulder, as well as a history of trauma, has been associated with rotator cuff tears. (10) A painful arc, noted by pain with overhead activity, is associated with mild rotator cuff disease and tendinopathy as well as rotator cuff tears. (10,15) A history of previous shoulder surgery is important because adhesive capsulitis and glenohumeral osteoarthritis can be early or late complications of surgery.

The patient's medical history, including joint problems, can help to narrow the differential diagnosis. Autoimmune diseases and inflammatory arthritis can affect the shoulder, resulting in erosions and wear in the glenohumeral joint, whereas diabetes and thyroid disorders can be associated with adhesive capsulitis. (8,9)

PHYSICAL EXAMINATION

Table 2 (10,15-19) summarizes some of the shoulder maneuver tests and the associated conditions. The preferred order of the examination is: inspection, palpation, range of motion and strength tests, and provocative tests.

Most Popular
Implementing Formal Project Management Processes: 9 Lessons Learned
Eight Major Job Trends For 2008
Telecom Predictions 2008: Deloitte
Managing & Communicating Change
Begin At The Beginning In Organizational Change Inspection should involve the entire shoulder, with proper exposure of the anterior, lateral, and posterior shoulder. A scar can indicate previous surgery or trauma. The presence of deformity, particularly of the acromioclavicular joint, often indicates an old trauma. Atrophy of the supraspinatus, and less commonly the infraspinatus, may be present with a chronic rotator cuff tear.

Palpation can identify areas of pathology, especially with the acromioclavicular joint. Isolated tenderness that is localized to the acromioclavicular joint is often indicative of acromioclavicular osteoarthritis. Subacromial tenderness may suggest rotator cuff pathology. Multiple trigger points around the shoulder may indicate non-shoulder pathology such as fibromyalgia. It is important to palpate both shoulders because certain structures can be painful (e.g., coracoid process, long head of biceps tendon), even in a healthy shoulder. The presence of a disproportionate amount of discomfort is helpful for diagnosis.

Range of motion should be evaluated in flexion, abduction, internal rotation, and external rotation. If the patient has a full active range of motion, a passive range of motion need not be assessed. Loss of active and passive ranges of motion is the hallmark of adhesive capsulitis, but it also can be found with moderate to severe osteoarthritis of the glenohumeral joint. Loss of an active range of motion, with a relatively preserved passive range of motion, is often present in patients with rotator cuff pathology. Pain with an active range of motion between 60 and 100 degrees of abduction is known as the "painful arc" and is associated with rotator cuff disease. (20)

There are numerous provocative tests for the shoulder. although knowledge of all the tests can be helpful to diagnose pathology, the primary care physician should be familiar with a standard set of tests that should be performed on every shoulder. The Hawkins' test is used to determine impingement (Figures 1a and 1b). Tests for rotator cuff pathology are the drop-arm rotator cuff test (Figures 2a and 2b); the empty-can supraspinatus test (Figure 3); the lift-off subscapularis test (Figure 4); and the external rotation test (Figure 5). The cross-body adduction test (Figure 6) is used to determine symptomatic acromioclavicular joint osteoarthritis, and the apprehension and relocation tests (Figure 7) are used to determine shoulder instability.

Complete article is available online.