AC Arthritis

Topic updated on 09/02/13 6:27pm
  • AC joint arthritis is caused by transmission of large loads through a small contact area
  • Epidemiology
    • demographics
      • more common with age but can occur by second decade of life
    • risk factors
      • prior AC separations
      • commonly associated with individuals who engage in constant heavy overhead activities
        • especially in weight-lifters and overhead throwing athletes 
  • Associated conditions
    • distal clavicle osteolysis 
  • Acromioclavicular Joint Anatomy 
  • Diarthrodial joint
    • articulates scapula to clavicle
    • contains a fibrocarilaginous disk
  • Ligaments
    • AC ligaments
      • provide anterior-posterior stability
        • posterior and superior AC ligaments most important for stability
    • Coracoclavicular ligaments
      • provide superior-inferior stability
  • Symptoms
    • activity related pain 
      • with overhead activity
      • with arm adduction
  • Physical exam 
    • palpation
      • pain with direct palpation of AC joint 
    • provocative tests
      • pain with cross body adduction test 
  • Radiographs 
    • recommended views
      • best evaluated using Zanca view (15 degree cephalic tilt) 
    • findings
      • can show osteophytes and joint space narrowing 
      • distal clavicle osteolysis
      • imaging findings do not always correlate with patient symptoms
  • MRI 
    • increased signal and edema in AC joint 
  • Nonoperative
    • activity modification and physical therapy
      • indications
        • indicated as a first line of treatment
      • technique
        • therapy should focus on strengthening and stretching of shoulder girdle
    • AC joint injection with corticosteroids 
      • can be both a diagnostic and therapeutic modality
  • Operative
    • arthroscopic vs open distal clavicle resection (Mumford procedure) 
      • indications
        • severe symptoms that have failed nonoperative treatment
      • outcomes
        • open vs. arthroscopic based on surgeon preference and comfort
          • arthroscopic resection has the advantage of allowing evaluation of the glenohumeral joint 
          • open procedures require meticulous repair of deltoid-trapezial fascia
  • Arthroscopic distal clavicle resection 
    • should resect only 0.5-1cm of distal clavicle
  • AC joint instability
    • anterior-posterior instability
      • can be due to aggressive surgical distal clavicle resection (>1-1.5cm)
      • due to aggressive debridement sacrificing posterior and superior AC ligaments 
    • superior-posterior instability
      • usually iatrogenic due to aggressive surgical resection compromising coracoclavicular ligaments
  • Continued pain after surgery
    • most commonly due to failure of posterior-superior resection of distal clavicle 
  • Heterotopic ossification
  • Deltoid dehiscence
    • due to inadequate deltoid-trapezial  junction repair in open surgery


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Qbank (1 Questions)

(SBQ07.12) Your partner performs distal clavicle excisions through an open approach while you prefer to use an arthroscopic approach. He notes that the literature shows both techniques have similar results with the exception of which of the following benefits of an arthroscopic approach? Topic Review Topic

1. Ability to evaluate the glenohumeral joint
2. Preservation of the coracoclavicular ligaments
3. Preservation of the inferior acromioclavicular ligaments
4. Lower complication rate
5. Decreased surgical time



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