#50 – Rotator Cuff Injuries



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Epidemiology

  • Up to 30% of the US population report having “shoulder pain”
    • 11 cases per 1000 patients per yearRotator cuff pathology is the most common reason patients seek treatment
  • Rotator cuff injuries also account for up to 40,000 surgeries per year in the US
  • Increases prevalence with age

Risk Factors

  • Repetitive, overhead activities
    • Swimming, weightlifting, tennis, throwing
  • Subacromial impingement
  • Scapular instability or dyskinesis
  • Older age
  • Diabetes
  • Hyperlipidemia and statin use
  • Trauma

Anatomy

  • There are four muscles of the rotator cuff
    • Supraspinatus (most commonly injured)
    • Infraspinatus
    • Subscapularis
    • Teres minor
  • The main function of the rotator cuff muscles is to assist in abduction and external rotation of the shoulder
    • Subscapularis assists internal rotation
  • Also compresses humeral head into the glenoid fossa
    • Stabilizes the glenohumeral joint
    • Counterbalances the elevating force of the deltoid

Mechanisms of Injury

  • Intrinsic mechanisms
    • Emphasize injury within the tendon that decrease integrity over time
      • Overload        
        • During eccentric muscle contraction in overhead activities
      • Degeneration
        • Microtears and calcifications from aging
        • Hypovascularity of the tendons
  • Extrinsic mechanisms
    • Emphasize compressive forces from structures surrounding the rotator cuff that can lead to impingement
      • Acromion, coracoclavicular ligaments, coracoid process
      • Glenohumeral instability

Signs and Symptoms

  • Pain with overhead activities and night pain
    • Over lateral deltoid
  • Weakness
    • Can be apparent even in asymptomatic individuals

Physical Examination

  • Need to evaluate the entire shoulder for other differential diagnoses, including:
    • Biceps tendonitis
    • Labral tears
    • Cervical radiculopathy
    • Thoracic outlet syndromes
  • Inspection
    • Chronic pathology can show atrophy of supraspinatus and infraspinatus
    • Asymmetric movement on active range of motion
      • Particularly with the scapula
  • Palpation
    • Tenderness of affected muscle
    • Focal subacromial tenderness
  • Range of Motion
    • Pain is usually elicited with:
      • 90o abduction
      • Internal rotation
    • Passive range of motion is better than active
  • Rotator cuff specific maneuvers include:

Diagnostic Studies

  • Plain radiographs are generally not helpful, but can be useful for:
    • Assessment when there is no response to conservative therapy
    • Recurrent rotator cuff tendinopathy
    • Anatomical evaluation prior to subacromial or glenohumeral joint injection
  • Ultrasound
    • Rapidly being considered the new gold standard
      • Allows for visualization of tendons in motion
      • Allows for comparison to contralateral side
  • Magnetic Resonance Imaging
    • Considered when:
      • Ruling out a tear when conservative therapy fails
      • Assess for a tear if clinically suspected
      • Aid in the diagnosis when pathology is unclear
    • Findings suggested of tears are:
      • Discontinuity on T1-weighted image and fluid signal on T2-weighted images
      • Fluid in the subacromial space on T2 images
      • Loss of subacromial fat plane on T1
      • Proliferative spur formation of acromion or AC joint

Treatment

  • Conservative Treatment for tendinopathy or chronic, partial tears
    • Cryotherapy
    • Rest
    • NSAIDs
    • Physical therapy (minimum of 6 weeks)
      • Initial stage – mobility
      • Second stage – strength
      • Third stage – function
    • Corticosteroid injections
  • Indications for Surgical Management
    • Acute, full-thickness tears in normal rotator cuff
    • New functional deficit with a known, partial tear
Arthroscopic Repair
“Full” Open Repair
“Mini” Open Repar

Cottage Physician



References

  1. Oh LS, Wolf BR, Hall MP, Levy BA, Marx RG. Indications for rotator cuff repair: a systematic review. Clinical orthopaedics and related research. 2007; 455:52-63. [pubmed]
  2. Teunis T, Lubberts B, Reilly BT, Ring D. A systematic review and pooled analysis of the prevalence of rotator cuff disease with increasing age. Journal of shoulder and elbow surgery. 2014; 23(12):1913-1921. [pubmed]
  3. Lin TT, Lin CH, Chang CL, Chi CH, Chang ST, Sheu WH. The effect of diabetes, hyperlipidemia, and statins on the development of rotator cuff disease: a nationwide, 11-year, longitudinal, population-based follow-up study. The American journal of sports medicine. 2015; 43(9):2126-32. [pubmed]
  4. Mehta S, Gimbel JA, Soslowsky LJ. Etiologic and pathogenetic factors for rotator cuff tendinopathy. Clinics in sports medicine. 2003; 22(4):791-812. [pubmed]
  5. Sørensen AK, Bak K, Krarup AL, et al. Acute rotator cuff tear: do we miss the early diagnosis? A prospective study showing a high incidence of rotator cuff tears after shoulder trauma. Journal of shoulder and elbow surgery. ; 16(2):174-80. [pubmed]
  6. Kim HM, Teefey SA, Zelig A, Galatz LM, Keener JD, Yamaguchi K. Shoulder strength in asymptomatic individuals with intact compared with torn rotator cuffs. The Journal of bone and joint surgery. American volume. 2009; 91(2):289-96. [pubmed]
  7. Lew HL, Chen CP, Wang TG, Chew KT. Introduction to musculoskeletal diagnostic ultrasound: examination of the upper limb. American journal of physical medicine & rehabilitation. 2007; 86(4):310-21. [pubmed]
  8. Roy JS, Braën C, Leblond J, et al. Diagnostic accuracy of ultrasonography, MRI and MR arthrography in the characterisation of rotator cuff disorders: a systematic review and meta-analysis. British journal of sports medicine. 2015; 49(20):1316-28. [pubmed]
  9. Rees JD, Wilson AM, Wolman RL. Current concepts in the management of tendon disorders. Rheumatology (Oxford, England). 2006; 45(5):508-21. [pubmed]
  10. Ainsworth R, Lewis JS. Exercise therapy for the conservative management of full thickness tears of the rotator cuff: a systematic review. British journal of sports medicine. 2007; 41(4):200-10. [pubmed]

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