> Table of Contents > Rotator Cuff Impingement Syndrome
Rotator Cuff Impingement Syndrome
Faren H. Williams, MD, MS
Minjin Fromm, MD
image BASICS
DESCRIPTION
  • Compression of rotator cuff tendons and subacromial bursa between the humeral head and the structures that makes up the coracoacromial arch and proximal humerus
  • Most common cause of atraumatic shoulder pain in patients >25 years of age
  • Primary symptom is pain that is most severe when the arm is abducted between 60 and 120 degrees (the “painful arc”).
  • Classically divided into three stages
    • Stage I: acute inflammation, edema, or hemorrhage of the underlying tendons due to overuse (typically in those age <25 years)
    • Stage II: progressive tendinosis that leads to partial rotator cuff tear along with underlying thickening or fibrosis of surrounding structures (commonly, ages 25 to 40 years)
    • Stage III: full-thickness tear (typically in patients age >40 years)
EPIDEMIOLOGY
Incidence
  • Shoulder pain accounts for 1% of all primary care visits.
  • Peak incidence of 25/1,000 patients/year occurs in patients aged 42 to 46 years.
  • Impingement responsible for 18-74% of shoulder pain diagnoses.
Prevalence
Prevalence of shoulder pain in general population ranges from ˜7% to 30%.
RISK FACTORS
  • Repetitive overhead motions (throwing, swimming)
  • Glenohumeral joint instability or muscle imbalance
  • Acromioclavicular arthritis or osteophytes
  • Thickened coracoacromial ligament
  • Shoulder trauma
  • Increasing age
  • Smoking
GENERAL PREVENTION
  • Proper throwing and lifting techniques
  • Proper strengthening to balance rotator cuff and scapula stabilizer muscles
image DIAGNOSIS
PHYSICAL EXAM
  • Examine patient for atrophy/asymmetry. Observe how the patient takes off his or her shirt as part of the exam.
  • Neer impingement test: Examiner stabilizes the scapula and moves the affected upper extremity through a flexion arc. Patient reports pain with flexion of the shoulder. Sensitivity: 78%. Specificity: 58% (1)[A]
  • Hawkins-Kennedy impingement test: Examiner places the arm in 90 degrees of forward flexion and then gently internally rotates the arm. End point for internal rotation is when the patient feels pain or when the rotation of the scapula is felt or observed by the examiner. Test is positive when patient experiences pain during the maneuver. Sensitivity: 74%. Specificity: 57% (1)[A]
  • Empty can test (supraspinatus): Examiner asks the patient to elevate and internally rotate the arm with thumbs pointing downward in the scapular plane. Elbow should be fully extended. Examiner applies downward pressure on upper surface of the arm. Test is positive when patient complains of pain with resistance. Sensitivity: 69%. Specificity: 62% (1)[A]
  • Lift-off test (subscapularis): Patient internally rotates the shoulder, placing the hand on ipsilateral buttock, then lifts hand off buttock against resistance. A tear in the subscapularis muscle produces weakness of this action. Sensitivity: 42%. Specificity: 97% (1)[A]
  • Drop-arm test: Patient fully elevates arm and then slowly reverses the motion. If the arm is dropped suddenly or the patient has extreme pain, the test is positive for a possible rotator cuff tear. Sensitivity: 21%. Specificity: 92% (1)[A]
  • Resisted external rotation: weakness suggestive of infraspinatus and/or teres minor tendon involvement
  • Examine cervical spine to rule out cervical pathology as source of shoulder pain.
  • Neurovascular exam of the upper extremity
DIFFERENTIAL DIAGNOSIS
  • Labral injury
  • Acromioclavicular arthritis (more common in older patients; positive cross-arm test—pain when affected arm is fully adducted across the chest in the horizontal plane)
  • Adhesive capsulitis (rotator cuff tendonitis leads to decreased use and atrophy of rotator cuff muscles, followed by contracture; linked to diabetes and may be related to prior trauma)
  • Anterior shoulder instability (prior trauma; more common in patients <25 years old)
  • Multidirectional instability
  • Biceps tendonitis or rupture (perform Speed and Yergason tests and look for visible or palpable defect of biceps—“Popeye sign”)
  • Calcific tendonitis
  • Cervical radiculopathy (spinal or foraminal stenosis, can test with Spurling maneuver)
  • Glenohumeral arthritis (evaluate with plain films)
  • Suprascapular nerve entrapment (look for focal muscle atrophy of supra- or infraspinatus)
  • Traumatic rotator cuff tear
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
  • Plain-film radiographs of the shoulder (three views): anteroposterior, axillary, scapular Y views
  • Plain films may reveal:
    • Osteoarthritis of the acromioclavicular and glenohumeral joints
    • Superior migration of the humeral head (indicative of a large rotator cuff tear)
    • Cystic change of the humeral head and sclerosis of the inferior acromion (indicative of chronic rotator cuff disease)
    • Calcific tendonitis
  • MRI is used to definitively assess rotator cuff tendinopathy, partial tears, and complete tears.
  • MR arthrogram is preferred for labral pathology.
  • Ultrasound is sensitive and specific for rotator cuff tears but is highly operator-dependent.
  • CT scan is preferred for bony pathology or for those unable to undergo MRI.
Diagnostic Procedures/Other
  • Lidocaine injection test
    • Inject lidocaine into the subacromial space:
      • Repeat impingement tests; if pain is completely relieved and range of motion is improved, likely impingement syndrome (rather than cuff tear).
    • Allows for more accurate strength testing on physical examination:
      • If strength is intact, rule out rotator cuff tear.
      • If range of motion does not improve in any plane, more likely adhesive capsulitis
    • Some pain relief and improved range of motion occurs after lidocaine injection with
      • Glenoid labral tear
      • Capsular strain
      • Glenohumeral osteoarthritis
      • Glenohumeral instability
  • A lack of any pain relief suggests other sources or inappropriate placement of injection.
Test Interpretation
May have tendinosis, tendonitis, or muscle/tendon tear
image TREATMENT
Anti-inflammatory agents plus aggressive rehabilitation can improve and fully resolve rotator cuff tendonitis in most patients.
P.933

GENERAL MEASURES
  • Rest
  • Ice or heat for symptom relief
  • Activity modification, with avoidance of aggravating activities, particularly overhead motions
  • Range-of-motion exercises
  • Rotator-cuff and adjacent muscle strengthening to enhance stability and prevent further injuries
MEDICATION
First Line
NSAIDs or other analgesic, often for 6 to 12 weeks
ISSUES FOR REFERRAL
Failure of conservative treatment, persistent pain, weakness, or complete tear of rotator cuff
ADDITIONAL THERAPIES
  • Supervised- or home-exercise regimens provide clinically significant pain reduction and improve function (2)[A].
  • Physical therapy is effective for short-term and longterm recovery of function (3)[A]:
    • Initial goal is to restore range of motion.
    • After pain resolves, gradually strengthen rotator cuff muscles in internal rotation, external rotation, and abduction.
COMPLEMENTARY & ALTERNATIVE MEDICINE
Acupuncture is of potential benefit to reduce pain and improve function, particularly when used with physical therapy (4)[A].
SURGERY/OTHER PROCEDURES
  • Steroid injections may have a significant benefit on pain and function in the short term but do not appear to have a significant long-term effect (5)[A]:
    • Risk for rotator cuff tears not significantly increased in those receiving subacromial steroid injections (6)[C].
  • No evidence that surgery is superior to conservative management, or that one surgical technique is superior to another for impingement syndrome (7)[A].
  • Platelet-rich therapies for musculoskeletal soft tissue injuries are increasingly common.
    • No apparent effect of platelet-rich plasma injection during arthroscopic rotator cuff repair on overall retear rates or shoulder-specific outcomes (8)[A],(9).
  • Extracorporeal shock wave therapy is currently under study as an emerging treatment for calcific tendonitis (10).
image ONGOING CARE
PATIENT EDUCATION
  • Physical rehabilitation is necessary, both in conservative course of treatment (i.e., NSAIDs, physical therapy, home exercises) and with surgical intervention. An aggressive trial of rehabilitation should be encouraged prior to extensive testing or surgical intervention. Providing pain relief prior to beginning a program of physical therapy improves adherence and outcomes.
  • Symptoms often recur if not fully addressed.
PROGNOSIS
  • Variable, depends on underlying pathology
  • Most patients improve with conservative management. Recovery can be slow.
  • Patients with more severe symptoms—those with symptoms for >1 year—are less likely to respond well with conservative therapies.
REFERENCES
1. Alqunaee M, Galvin R, Fahey T. Diagnostic accuracy of clinical tests for subacromial impingement syndrome: a systematic review and meta-analysis. Arch Phys Med Rehabil. 2012;93(2):229-236.
2. Kuhn JE. Exercise in the treatment of rotator cuff impingement: a systematic review and a synthesized evidence-based rehabilitation protocol. J Shoulder Elbow Surg. 2009;18(1):138-160.
3. Green S, Buchbinder R, Hetrick S. Physiotherapy interventions for shoulder pain. Cochrane Database Syst Rev. 2003;(2):CD004258.
4. Vas J, Ortega C, Olmo V, et al. Single-point acupuncture and physiotherapy for the treatment of painful shoulder: a multicentre randomized controlled trial. Rheumatology (Oxford). 2008;47(6):887-893.
5. Gaujoux-Viala C, Dougados M, Gossec L. Efficacy and safety of steroid injections for shoulder and elbow tendonitis: a meta-analysis of randomised controlled trials. Ann Rheum Dis. 2009;68(12):1843-1849.
6. Bhatia M, Singh B, Nicolaou N, et al. Correlation between rotator cuff tears and repeated subacromial steroid injections: a case-controlled study. Ann R Coll Surg Engl. 2009;91(5):414-416.
7. Gebremariam L, Hay EM, Koes BW, et al. Effectiveness of surgical and postsurgical interventions for the subacromial impingement syndrome: a systematic review. Arch Phys Med Rehabil. 2011;92(11):1900-1913.
8. Chahal J, Van Thiel GS, Mall N, et al. The role of platelet-rich plasma in arthroscopic rotator cuff repair: a systematic review with quantitative synthesis. Arthroscopy. 2012;28(11):1718-1727.
9. Moraes VY, Lenza M, Tamaoki MJ, et al. Platelet-rich therapies for musculoskeletal soft tissue injuries. Cochrane Database Syst Rev. 2013;(12):CD010071. doi:10.1001/14651858. CD010071.pub2.
10. Ioppolo, F, Tattoli M, Di Sante L, et al. Clinical improvement and resorption of calcifications in calcific tendinitis of the shoulder after shock wave therapy at 6 months’ follow-up: a systemic review and meta-analysis. Arch Phys Med Rehabil. 2013;94(9):1699-1706.
Additional Reading
&NA;
  • Baumgarten KM, Gerlach D, Galatz LM, et al. Cigarette smoking increases the risk for rotator cuff tears. Clin Orthop Relat Res. 2010;468(6): 1534-1541.
  • Burbank KM, Stevenson JH, Czarnecki GR, et al. Chronic shoulder pain: part I. Evaluation and diagnosis. Am Fam Physician. 2008;77(4):453-460.
  • Burbank KM, Stevenson JH, Czarnecki GR, et al. Chronic shoulder pain: part II. Treatment. Am Fam Physician. 2008;77(4):493-497.
  • Cumpston M, Johnston RV, Wengier L, et al. Topical glyceryl trinitrate for rotator cuff disease. Cochrane Database Syst Rev. 2009;(3):CD006355.
  • Hanchard NC, Lenza M, Handoll HH, et al. Physical tests for shoulder impingements and local lesions of bursa, tendon or labrum that may accompany impingement. Cochrane Database Syst Rev. 2013;(4):CD007427.
  • Hegedus EJ, Goode A, Campbell S, et al. Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Br J Sports Med. 2008;42(2):80-92.
  • Kennedy DJ, Visco CJ, Press J. Current concepts for shoulder training in the overhead athlete. Curr Sports Med Rep. 2009;8(3):154-160.
Codes
&NA;
ICD10
  • M75.40 Impingement syndrome of unspecified shoulder
  • M75.110 Incmpl rotatr-cuff tear/ruptr of unsp shoulder, not trauma
  • M75.120 Complete rotatr-cuff tear/ruptr of unsp shoulder, not trauma
Clinical Pearls
&NA;
  • Consider impingement syndrome in patients involved with repetitive overhead activities (e.g., swimming, throwing) who present with shoulder pain.
  • Atraumatic shoulder pain in middle age often represents rotator cuff tendonitis.
  • Supraspinatus tendon is most commonly affected in impingement syndrome.
  • Neer and Hawkins tests specifically check for shoulder impingement.
  • The empty can maneuver tests for weakness of supraspinatus muscle.
  • The drop-arm test is specific for rotator cuff tear.
  • Physical therapy over 6 to 12 weeks promotes return to function
  • Most patients with shoulder impingement respond well to conservative management. Those who don’t should be referred for surgical evaluation.