Shoulder pain: 3 cases to test your diagnostic skills

,; ,; ,

Applied Evidence

Shoulder pain: 3 cases to test your diagnostic skills

J Fam Pract. 2012 January;61(1):16-22

PDF Download

References

1. Van der Windt DA, Koes BW, De Jong BA, et al. Shoulder disorders in general practice: incidence, patient characteristics, and management. Ann Rheum Dis. 1995;54:959-964.

2. Johansson K, Adolfsson L, Foldevi M. Attitudes toward management of patients with subacromial pain in Swedish primary care. Fam Pract. 1999;16:233-237.

3. Kibler WB, McMullen J. Scapular dyskinesis and its relation to shoulder pain. J Am Acad Orthop Surg. 2003;11:142-151.

4. Kibler WB. The role of the scapula in athletic shoulder function. Am J Sports Med. 1998;26:325-337.

5. Vanermen B, Aertgeerts M, Hoogmartens M, et al. The syndrome of Parsonage and Turner. Discussion of clinical features with a review of 8 cases. Acta Orthop Belg. 1991;57:414-419.

6. Misamore GW, Lehman DE. Parsonage-Turner syndrome (acute brachial neuritis). J Bone Joint Surg. 1996;78:1405-1408.

7. Stevenson J, Trojian T. Evaluation of shoulder pain. J Fam Pract. 2002;51:605-611.

8. Miller JD, Pruitt RN, McDonald TJ. Acute brachial plexus neuritis: an uncommon cause of shoulder pain. Am Fam Physician. 2000;62:2067-2072.

9. Eubanks JD. Cervical radiculopathy: nonoperative management of neck pain and radicular symptoms. Am Fam Physician. 2010;81:33-40.

10. Malanga GA, Landes P, Nadler SF. Provocative tests in cervical spine examination: historical basis and scientific analyses. Pain Physician. 2003;6:199-205.

11. Huston M, Ellis R. eds. Textbook of Musculoskeletal Medicine. Oxford, UK: Oxford University Press; 2005.

12. Mahaffey BL, Smith PA. Shoulder instability in young athletes. Am Fam Physician. 1999;59:2773-2782, 2787.

13. Petron DJ, Khan U. The shoulder and upper extremity. In: McKeag DB, Moeller JL. ACSM’s Primary Care Sports Medicine. 2nd ed. Philadelphia, Pa: Wolters Kluwer, Lippincott Williams & Wilkins; 2007:359–373.

14. Woodward TW, Best TM. The painful shoulder: part I. clinical evaluation. Am Fam Physician. 2000;61:3079-3088.

15. Kelly BT, Kadrmas WR, Speer KP. The manual muscle examination for rotator cuff strength: an electromyographic investigation. Am J Sports Med. 1996;24:581-588.

16. Murrell GA, Walton JR. Diagnosis of rotator cuff tears. Lancet. 2001;357:769-770.

17. Richards RR, An KN, Bigliani LU, et al. A standardized method for the assessment of shoulder function. J Shoulder Elbow Surg. 1994;3:347-352.

18. Neer CS, Welsh RP. The shoulder in sports. Orthop Clin North Am. 1977;8:583-591.

19. Hawkins RJ, Kennedy JC. Impingement syndrome in athletics. Am J Sports Med. 1980;8:151-163.

20. Itoi E, Kido T, Sano A, et al. Which is more useful, the “full can test” or the “empty can test,” in detecting the torn supraspinatus tendon? Am J Sports Med. 1999;27:65-68.

21. Boettcher CE, Ginn KA, Cathers I. The ‘empty can’ and ‘full can’ tests do not selectively activate supraspinatus. J Sci Med Sport. 2009;12:435-439.

The take-away message: Rule out instability
The shoulder is one of the most complex joints in the body. The rotator cuff structures, the glenoid labrum, and the collective capsular ligaments provide structural stability to the glenohumeral joint.^12,13 The shoulder is vulnerable to instability because the shallow glenoid fossa offers little bony support for the humeral head. Thus, instability should always be included in an assessment of shoulder pain.

FAST TRACK

Instability should always be included in an assessment of shoulder pain.

Key factors to consider in identifying shoulder instability include the location of the pain, the direction of traumatic force applied, the presence of a known complete dislocation vs apprehension with specific movement, the position of the arm in which pain is elicited, a previous occurrence of instability (subluxation or dislocation), and the presence of tingling or numbness.^12-14 The maneuvers detailed in TABLE 2^12-14 can help identify instability, as they did in this case. Patients with hypermobility are at increased risk for shoulder instability, so a targeted exam and patient history aimed at identifying signs and symptoms of hypermobility is needed, as well.

Ask the patient to attempt to:

bend the thumb to the volar forearm
place hands to the floor with hyperextended knees
perform maximal hyperextension of the fifth metacarpophalangeal joint (>90° is a positive result).

Findings from the medical history that indicate a predisposition to instability include generalized joint laxity, Ehlers-Danlos syndrome, Marfan syndrome, osteogenesis imperfecta, hyperhomocysteinuria, hyperlysinemia, benign joint hypermobility syndrome, juvenile rheumatoid arthritis, and previous shoulder or patellar dislocations.

Imaging tips: Scapular Y and/or axillary lateral views should always be included when ordering imaging studies for suspected instability/dislocations, as 50% of posterior dislocations are missed on standard shoulder x-rays that do not include them.¹² In reviewing the x-rays, it is important to look for signs of a compression fracture of the posterior humeral head (known as a Hill-Sachs lesion) for anterior shoulder dislocations, and fractures to the anterior glenoid rim (known as a Bankart lesion).^12-14

CASE 3 The history: Robert, a right-handed, 50-year-old motorcycle instructor, came to our office because of chronic right shoulder pain. The pain, located over the anterior portion of the glenohumeral joint, developed insidiously about 3 or 4 years ago, the patient reported. He had finally decided to seek help because he’d recently experienced an acute exacerbation of pain brought on by shoveling snow, after which he also noticed associated weakness, a clicking/popping on active motion, and mild loss of motion.

The physical: Robert’s cervical spine exam was unremarkable. He demonstrated full active range of motion (ROM) without exacerbation of right shoulder symptoms, and special tests for disc pathology at the neck were negative. Active ROM testing of the right shoulder revealed full abduction, with only minimal pain; full flexion, with moderate pain noted initially at 49°; full extension, with a painful arc noted at 50°; and full horizontal adduction, with a painful arc noted at the halfway point. The testing also revealed that his right thumb was 3 inches lower than the left on reaching for the opposite scapula. At the superior aspect of the acromioclavicular (AC) joint, 2+ tenderness was noted; 3+ tenderness was noted at the greater tubercle of the humerus.

After inspecting the shoulder region for alterations in bony landmarks, muscle bulk, carrying position, and movement characteristics, palpation of the region was performed.

When assessing shoulder strength, there are a variety of tests for each functioning component of the rotator cuff structures (TABLE 3).^15-17 Manual muscle tests revealed: 4-/5 on external rotation (French horn test), 3+/5 on the lift-off test, and 5-/5 on all other tests for right shoulder function. Impingement testing was slightly positive, or pain producing, on Hawkins and Neer tests.^18,19 For the Hawkins test, the examiner flexes the arm to 90° of shoulder flexion with the elbow flexed at 90°, then internally rotates the shoulder. For the Neer test, the arm is fully elevated in the scapular plane and internally rotated by the examiner.

The subscapularis muscle, which functions primarily in internal rotation, is tested by the French horn and lift-off tests. The teres minor muscle, which performs external rotation, is tested by the French horn test of external rotation. And the supraspinatus muscle, which performs abduction and external rotation, is tested by the empty can (also known as the Jobe) and full can tests. Some researchers suggest that the empty can test is better for diagnosing impingement, based on evidence showing that the full can test is better at diagnosing supraspinatus tears because it causes less pain during testing.²⁰

TABLE 3
Suspect rotator cuff involvement?^7,15-17