Injectable corticosteroids for the painful shoulder: Patient evaluation
Injectable corticosteroids for the painful shoulder: Patient evaluation
A variety of painful shoulder conditions might warrant consideration for management with corticosteroid injections. Most physicians have a general knowledge of how to obtain a pertinent history for shoulder problems, but some may have minimal training for making a diagnosis of some specific shoulder conditions. For example, differentiating cervical, acromioclavicular (AC), subacromial (SA), glenohumeral (GH), and biceps tendon pathology may be particularly challenging.
Various aspects of the physical examination are used frequently to isolate the anatomical source of a patient's shoulder pain, especially provocative maneuvers, signs, and tests; radiography also is useful. Knowing how to perform provocative maneuvers and evaluate the results is critical for making the diagnosis and identifying potential corticosteroid/anesthetic injection sites.
This 3-part article describes the diagnostic and therapeutic uses of corticosteroid/anesthetic injections for painful shoulder conditions. In the first part ("The use and misuse of injectable corticosteroids for the painful shoulder," The Journal of Musculoskeletal Medicine, February 2008, page 78), we reviewed the mechanism of action of corticosteroids, current preparations, indications and contraindications, adverse effects, misuses, and lack of uniform standards of care. This second part discusses physical examination and radiographic evaluation procedures for determining when to inject corticosteroids. In the third part, to appear in a later issue of this journal, we will illustrate techniques for administering injections for specific shoulder complaints. We hope that this discussion will encourage the development of more uniform guidelines and help improve injection accuracy.
A 16-step physical examination
There are various descriptions of how to perform a comprehensive shoulder examination.1,2 The examination performed for a typical patient seen in our orthopedic shoulder specialty clinic includes 16 basic steps (Table 1). In this examination, radiographs are not viewed initially to avoid bias that can lead to a premature/inaccurate diagnosis (eg, when AC arthritis is seen on radiographs but the AC joint is not a significant source of pain).The steps are as follows:
- Step 1. Inspect and palpate the shoulder. This is facilitated by asking women to wear a shoulder examination gown or having men remove their shirt.
- Step 2. The patient is asked to demonstrate active flexion and abduction motion until he or she feels significant pain in each direction. This provides the examiner with a general "feel"—at the beginning of the examination—for the magnitude of the patient's shoulder pain and functional limitations. If the patient cannot raise his arm more than about 70° to 80° in either flexion or abduction, he probably has a full-thickness supraspinatus tear, significant arthritis, adhesive capsulitis (frozen shoulder), or all of these conditions.
- Step 3. The painful arc sign is elicited by asking the patient to actively elevate his arm in the scapular plane until full elevation is reached and then having him lower the arm in the same arc. The test result is positive when the patient has pain or painful catching between 60° and 120° of elevation.
- Step 4. The drop-arm maneuver result is considered positive if the patient's arm drops suddenly or he experiences severe pain (generally seen around 90° of elevation) and probably represents rotator cuff pathology. In some cases of significant rotator cuff pathology, the patient can hold his arm in abduction, but applying a small amount of downward force causes the arm to drop.
- Step 5. The examiner performs the passive external rotation maneuver by externally rotating the patient's arm with his elbow at his side.This maneuver helps detect pain and crepitation that might be attributable to GH arthritis.
- Step 6. If pain is elicited, radiographs are viewed (the first radiograph viewing) to determine the severity of GH arthritis and humeral head elevation (both are present in rotator cuff tear arthropathy, which is a chronic rotator cuff tear with GH arthritis). For patients who do not have GH arthritis, the passive external rotation maneuver usually is pain-free. If radiographs reveal significant GH arthritis, the examiner should anticipate that the patient probably also will have difficulty in the portion of the examination involving possible SA impingement syndromes. During all examination maneuvers, observe for painful facial expressions and frequently ask the patient whether he is experiencing pain. Doing so is especially important with additional provocative maneuvers, which can be quite painful.
- Step 7. Determining the difference between active and passive motion in all planes also is important. If motion is generally restricted, and active and passive ranges are similar, the patient might have adhesive capsulitis or moderate to severe GH arthritis. If crepitation is felt and pain is evoked during external rotation (with the patient's elbow at his side), there may be significant GH arthritis; this scenario is more common than adhesive capsulitis.
- Step 8. Next, perform the Neer impingement and Hawkins-Kennedy impingement reinforcement maneuvers to evaluate SA impingement syndromes. The Neer impingement maneuver is performed with the examiner causing forced forward flexion of the patient's upper extremity (with elbow extended and forearm pronated) while the examiner's other hand prevents compensatory upward scapular rotation.This maneuver causes the greater tuberosity of the humerus to encroach on or impinge against the anterior acromion.3-5
The Hawkins-Kennedy maneuver is performed by forward flexion of the humerus to 90° combined with maximal internal rotation of the shoulder.6 Most patients seen in our shoulder specialty clinic have pain with 1 or both of these maneuvers, reflecting the somewhat high prevalence of SA impingement syndromes.
- Step 9. The examiner performs the cross-body adduction maneuver by having the patient forward flex his shoulder to 90° and by adducting the arm across the body. The result is positive if the test causes pain in the shoulder region. This maneuver helps determine the presence of significant AC pathology and may elicit pain from the SA space or nearby regions. The pain elicited with this maneuver is compared with that of the previous maneuvers to further determine the source of pain.
- Step 10. The supraspinatus muscle strength test is performed by resisting abduction of the patient's arm elevated to 90° in the plane of the scapula.The forearm is in internal rotation.
- Step 11. In the infraspinatus muscle strength test, the patient's elbow is flexed to 90° and the arm is adducted to the trunk (at the side) in neutral rotation. The examiner then applies an internal rotation force to the arm while the patient resists.The result is positive if the patient "gives way" because of weakness or pain or if there is a positive external rotation lag sign.
For that sign, the patient's arm is positioned with the elbow at the side and flexed to 90°. Then the arm is maximally externally rotated by the examiner and the patient is asked to hold this position. If the patient cannot and the arm falls into internal rotation, it is considered a positive test result. GH instability also should be assessed, especially in patients who are younger than 45 years, because it can cause secondary SA impingement.
- Step 12. Next, perform provocative tests for biceps pathology, including the Yergason, Speed, and biceps/shoulder rotation maneuvers. These tests help determine whether pathology attributable to the biceps tendon warrants injecting the biceps sheath.
The Yergason maneuver is performed by having the patient flex his elbow to 90° and actively supinate his forearm against resistance applied by the examiner to elicit pain at the bicipital groove. In the Speed maneuver, have the patient forward flex his humerus with his forearm supinated and elbow extended; the examiner applies resistance.
In the biceps/shoulder rotation maneuver, the examiner's finger applies pressure on the patient's anterior shoulder (over the biceps tendon sheath) while the examiner passively moves the patient's arm slowly in internal and external rotation. The result is positive if pain occurs when the biceps sheath is anterior (when the arm is in about 10° of internal rotation).
- Step 13. The patient also may have pain in the posterior aspect of the shoulder caused by scapulothoracic bursitis; if it is present, an injection may be given. This pathology usually is seen as subscapular pain and crepitation or a "popping/catching" sensation with arm elevation.
To detect these signs, the examiner performs the subscapular crepitation maneuver by placing his hand on the posterior aspect of the scapula while the patient tries to reproduce the symptoms. We also examine for scapular winging (the medial border of the scapula moves away from the posterior chest wall); if it is seen, electrodiagnostic studies (eg, nerve conduction studies/electromyography) might be warranted.
- Step 14. The Spurling maneuver is performed to determine whether some percentage of the patient's pain is the result of cervical pathology.7 The examiner rotates and bends the patient's neck toward the affected shoulder with downward compression applied on the patient's head. The neck should be flexed and extended. When the Spurling maneuver elicits significant pain (estimated at more than 70% of the "shoulder" pain) but provocative maneuvers for the SA space and AC and GH joints do not, shoulder injections usually are not indicated and diagnostic workup for neck pathology may be commenced (eg, neurological testing, cervical spine radiography, and MRI).
- Step 15. In this step, the patient usually is asked to lie on his back for the "crank" maneuver, which helps detect GH instability (pain or discomfort with excessive translation of the humeral head on the glenoid fossa during active shoulder motion) or subluxability (symptomatic instability without complete separation or dislocation of the articular surfaces).The crank maneuver is performed by having the involved shoulder positioned so that the scapula is supported by the edge of the examining table and the proximal humerus is placed in various degrees of external rotation and abduction. Patients with significant instability usually worry that there will be pain or the shoulder will feel like it is "slipping" out of the joint.
The Jobe relocation maneuver (relocation test) provides confirmation that these symptoms result from instability. Confirmation is obtained when the pain/apprehension from the crank maneuver subsides with the application of a posterior-directed force to the upper arm.
Presence of the "sulcus" sign also helps determine the presence of instability. This sign is elicited by pulling firmly downward on the patient's arm while he is sitting with the arm at his side; observation of a depression, or sulcus, forming just lateral to the acromion is a positive finding.
The patient also usually sits upright for the "jerk" maneuver, which tests for posterior instability. The patient internally rotates and forward flexes his humerus to 90°.The examiner then stabilizes the scapula with 1 hand; the other causes a posterior force by pressing in a posterior direction on the elbow. A positive result is felt with the humeral head sliding excessively backward. As in all instability testing, evaluation of the contralateral side is essential for detecting significant asymmetrical findings.
If there is evidence of GH instability without significant GH arthritis, no injection should be given at the GH joint, because doing so could mask the protective effect of pain. However, there may be SA symptoms that are secondary to GH instability ("secondary SA impingement"). In these cases, SA injections might be warranted. At this time, the examiner should have sufficient information to determine whether a corticosteroid injection is warranted.
- Step 16. After the first 15 steps of the shoulder examination are completed, the radiographs are reexamined (the second radiograph viewing), even though the physical examination is not yet complete. Additional physical examination steps could include deep tendon reflex testing, neurosensory evaluation, and other special tests.
An assessment of acromial morphology is made.There are 3 types of acromion that may be associated with rotator cuff pathology. Type 1 acromion has a flat undersurface and is associated with the lowest prevalence of rotator cuff pathology, type 2 has a curved undersurface, and type 3 has a hooked undersurface.
We also determine the degree of arthritis at the GH joint, which may be quantified as 0, normal; 1, mild (osteophytes smaller than 3 mm on the humerus); 2, moderate (osteophytes 3 to 7 mm on the humerus); or 3, severe (osteophytes larger than 7 mm on the humerus) (Figure).8 Arthritis of the AC joint also may be categorized (none, mild, moderate, or severe).8 Calcific tendinitis, which typically occurs near the insertion of the supraspinatus, may be quantified as 1, small (less than 0.5 mm); 2, medium (0.5 to 1.5 mm); or 3, large (greater than 1.5 mm).9