Jump to content
We need you! See something you could improve? Make an edit and help improve WikSM for everyone.

Acromioclavicular Joint Separation

From WikiSM

Other Names

  • Shoulder Separation
  • Shoulder Sprain
  • AC Sprain
  • AC Joint Sprain
  • AC Dislocation
  • Acromioclavicular Joint Dislocation

Background

  • This page refers to all traumatic injuries to the Acromioclavicular Joint including
    • Sprains
    • Dislocations
    • Separations

History

  • Needs to be updated

Epidemiology

  • Thought to be under-estimated due to many mild injuries not seeking medical attention
  • Represents 9% of all shoulder injuries (need citation)
  • 50% of all AC dislocations occur to individuals in their 20s (need citation)
  • Types 1 and 2 injuries account for most AC separations

Introduction

Labeled radiograph of the AC joint[1]

General

  • Characterized by anterior/lateral shoulder pain with or without deformity
  • Mechanism of injury is primarily by direct impact over the AC joint or lateral shoulder
  • Diagnosis is clinical and confirmed with radiographs or ultrasound
  • Management is generally considered nonsurgical

Etiology

  • Simple falls
  • High energy trauma
  • Sports
  • From fall or contact sport
  • Arm is adducted

Anatomy of the Acromioclavicular joint

Associated Injuries

Risk Factors

  • Male > Female
  • Sports
    • Contact and collision sports
    • Skiing
    • Cycling

Differential Diagnosis

Clinical Features

Clinical demonstration of the crossover or cross-arm test[3]

History

  • Patient should describe some trauma
  • Shoulder pain at or close to AC joint
  • Deformity may or may not be present

Physical: Physical Exam Shoulder

  • Most commonly, tenderness over AC joint
  • Inspection may show asymmetry of shoulders or swelling at the AC joint
  • Range of Motion is usually reduced due to pain acutely
  • Pain with adduction of the shoulder and possibly with shoulder abduction and flexion
  • Deformity (step-off) of AC joint with type III injuries and higher
  • Type III and V may show instability of the lateral clavicle when depressed manually ("piano key" phenomenon)

Special Tests

Evaluation

  • Grade 3 AC Joint Separation
    Grade 3 AC Joint Separation
  • Zanca view showing normal AC joint (right) and grade 3 separation (left)
    Zanca view showing normal AC joint (right) and grade 3 separation (left)
X-ray shows the coracoclavicular distance (white arrow)[4]
3A: Type 1 AC Joint Sprain. A sprain or incomplete tear of the joint capsule and its reinforcing AC ligament. May note some mild effusion in the joint space. 3B: Type 2 AC Joint Sprint. A complete tear of the joint capsule and its reinforcing AC ligament. Intact coraco-clavicular ligaments remain. The joint space is widened, and clavicle is elevated above acromion.[5]

Radiographs

  • Standard Radiographs Shoulder
    • May be normal in grade I/II
    • More obvious in severe grade II or grade III
  • Zanca View
    • Sometimes referred to as the AC joint view[6]
    • Beam is tilted cephalic 10 - 15°
    • Provides superior AC joint evaluation
    • Recommend bilateral evaluation for comparison
  • Other Views
    • Basmania View: scapular Y performed with cross-body adduction stress
    • Stryker notch views can assess for coracoid fracture
    • Weighted stress view: no longer used
  • Coracoclavicular Distance
    • Measures the distance between superior cortex of coracoid process and undersurface of clavicle
    • Used to assess the integrity of the Coracoclavicular Ligament radiographically
    • The average distance between the inferior aspect of the clavicle and the coracoid is 1.1 to 1.3 cm

CT

  • CT has not been shown to improve diagnostic yield
  • It might be indicated if other pathology is identified

MRI

  • Can directly assess AC and CC ligaments
  • Useful if surgical intervention is being considered

Ultrasound

  • Can be used to evaluate the AC joint

Classification

Rockwood Classification of Acromioclavicular Injuries

Type AC Ligaments CC Ligaments Deltopectoral Fascia CC Distance AC Joint (Xray)
I Sprained Intact Intact Normal Normal
II Disrupted Sprained Intact <25% Widened
III Disrupted Disrupted Disrupted 25%-100% Widened
IV Disrupted Disrupted Disrupted Increased Posterior displaced clavicle
V Disrupted Disrupted Disrupted 100-300% N/A
VI Disrupted Disrupted Disrupted Decreased Inferior displaced clavicle

Management

Rockwood classification[7]

Shoulder Sling

Types I and II

  • Universally nonoperative
  • Analgesia with ice, NSAIDS, Acetaminophen, et
  • Immobilization: Shoulder Sling
    • Discontinue once asymptomatic
    • Type I: Typically 1-3 weeks
    • Type II: Longer, up to 4 weeks[8]
  • Activity modification
    • Type II injuries may require early rehabilitation program with passive and active shoulder ROM exercises
    • Rotator cuff, scapular stabilization, and trunk strengthening exercises as pain resolves
    • Heavy lifting and contact activities only once extremity is pain free and symmetric ROM is acheived
  • Consider Corticosteroid Injection in refractory cases

Type III

  • Management is controversial
    • Not a lot of high level evidence to guide decision making
    • General consensus is to advocate for initial nonoperative management.
    • Individualized treatment based on patient activity level, impairment, and occupation
    • Consider surgical repair in acute, young patients
    • Comparably high satisfaction with operative and nonoperative treatment though higher complication rates in those treated surgically[9]
  • Nonoperative treatment
    • Similar to Type I, II

Type IV - VI

  • Generally considered surgical
  • Technique
    • Many described in literature
    • ORIF most common

Rehab and Return to Play

Rehabilitation

  • Needs to be updated

Return to Play

  • Return to play once pain completely resolved and equal active ROM in bilateral shoulders
  • Followed by adequate strength training
  • Recovery generally takes 6 weeks for Type II injuries and 12 weeks for Type III injuries

Prognosis and Complications

Prognosis

  • Needs to be updated

Complications

See Also

Internal

External

References

  1. ↑ Image courtesy of radiologymasterclass.co.uk
  2. ↑ . Tischer T, Salzmann GM, El-Azab H, Vogt S, Imhoff AB. Incidence of associated injuries with acute acromioclavicular joint dislocations types III through V. Am J Sports Med. 2009 Jan;;37(1):136-9. Epub 2008 Aug 25.
  3. ↑ Manske, Robert, and Todd Ellenbecker. "Current concepts in shoulder examination of the overhead athlete." International journal of sports physical therapy 8.5 (2013): 554.
  4. ↑ Kang, Ki-Ser, et al. "Long term follow up results of the operative treatment of the acromioclavicular joint dislocation with a Wolter plate." Journal of the Korean Fracture Society 22.4 (2009): 259-263.
  5. ↑ Manske, Robert C., et al. "MSK Diagnostic Ultrasound for the Assessment of the Acromioclavicular Joint." International Journal of Sports Physical Therapy 19.1 (2024): 1516.
  6. ↑ Zanca P. Shoulder pain: involvement of the acromioclavicular joint. (Analysis of 1,000 cases). Am J Roentgenol Radium Ther Nucl Med. 1971 Jul;112(3):493-506.
  7. ↑ Case courtesy of Andrew Murphy, Radiopaedia.org, rID: 72436
  8. ↑ Park JP, Arnold JA, Coker TP, Harris WD, Becker DA. Treatment of acromioclavicular separations. A retrospective study. Am J Sports Med. 1980 Jul-Aug;8(4):251-6
  9. ↑ Glick JM, Milburn LJ, Haggerty JF, Nishimoto D. Dislocated acromioclavicular joint: follow-up study of 35 unreduced acromioclavicular dislocations. Am J Sports Med. 1977 Nov-Dec;5(6):264-70.
  10. ↑ Mouhsine E, Garofalo R, Crevoisier X, Farron A. Grade I and II acromioclavicular dislocations: results of conservative treatment. J Shoulder Elbow Surg. 2003 NovDec;12(6):599-602.
Created by:
John Kiel on 4 July 2019 08:23:12
Last edited:
18 April 2025 00:47:02
Categories:
Retrieved from "https://wikism.org/w/index.php?title=Acromioclavicular_Joint_Separation&oldid=31839"