Acromioclavicular joint configuration

Dr Henry Knipe ◉ ◈ and A.Prof Frank Gaillard ◉ ◈ et al.

There is much variation in acromioclavicular joint configuration, which may be confused with pathology. The relationship of the acromion to the distal clavicle at the AC joint can be described in the coronal plane as ^1-3:

horizontal: normal
low-lying: associated with shoulder impingement (unfortunately, there are no criteria for distinguishing a low-lying acromion from a high-riding clavicle) ²
inferolateral: associated with shoulder impingement

References

Anatomy: Upper limb

skeleton of the upper limb
- clavicle
  - conoid tubercle
  - supraclavicular foramen
- scapula
- humerus
  - supracondylar spur
  - olecranon foramen
- radius
- ulna
- carpal bones (mnemonic)
  - scaphoid
    - bipartite scaphoid
  - lunate
    - lunate morphology
  - triquetrum
  - pisiform
  - trapezium
  - trapezoid
  - capitate
  - hamate
  - variants
    - carpal coalition
      - luno-triquetral coalition
      - capito-hamate coalition
- metacarpals
- phalanges
  - terminal tuft
- accessory ossicles of the upper limb
  - accessory ossicles of the shoulder
    - os acromiale
  - accessory ossicles of the elbow
    - os supratrochleare dorsale
    - patella cubiti
  - accessory ossicles of the wrist (mnemonic)
    - os centrale carpi
    - os epilunate
    - os styloideum
    - os hamuli proprium
    - lunula
    - os triangulare
    - trapezium secondarium
    - os paratrapezium
    - os radiostyloideum (persistent radial styloid)
joints of the upper limb
- shoulder joint
  - articulations
  - associated structures
    - joint capsule
    - subacromial bursa
    - subcoracoid bursa
    - ligaments
      - coracoclavicular ligament
        
        conoid ligament
        
        trapezoid ligament
      - costoclavicular ligament
  - movements
    - scapular retraction (adduction)
    - scapular protraction (abduction)
    - scapular elevation
    - scapular depression
    - arm abduction
    - arm adduction
    - arm flexion
    - arm extension
    - arm internal rotation (medial)
    - arm external rotation (lateral)
  - blood supply - scapular anastomosis
  - ossification centers
- elbow joint
  - proximal radioulnar joint
  - ligaments
    - medial (ulna) collateral ligament complex
    - lateral (radial) collateral ligament complex
  - associated structures
    - bicipitoradial bursa
    - olecranon bursa
  - alignment
  - blood supply - elbow anastomosis
  - development
    - elbow ossification (mnemonic)
    - elbow ossification centers
- wrist joint
  - articulations
  - ligaments
    - intrinsic ligaments
    - extrinsic ligaments
  - associated structures
    - extensor retinaculum
    - flexor retinaculum
    - joint capsule
  - alignment
    - carpal arcs
  - ossification
- hand joints
  - movements
  - articulations
    - carpometacarpal joint
      - triscaphe joint
    - metacarpophalangeal joint
      - palmar ligament (plate)
      - collateral ligament
    - interphalangeal joint
      - palmar ligament (plate)
      - collateral ligament
spaces of the upper limb
muscles of the upper limb
- shoulder girdle
- anterior compartment of the arm
- posterior compartment of the arm
- anterior compartment of the forearm
  - superficial
  - intermediate
    - flexor digitorum superficialis
  - deep
- posterior compartment of the forearm (extensors)
  - superficial
  - deep
- hand (mnemonic)
  - thenar muscles
  - hypothenar muscles
    - abductor digiti minimi
    - flexor digiti minimi brevis
    - opponens digiti minimi
    - palmaris brevis (technically not a hypothenar muscle)
  - intermediate muscles
- accessory muscles
  - anconeus epitrochlearis
blood supply to the upper limb
- arteries
- veins
innervation of the upper limb
- intercostobrachial nerve
- brachial plexus (mnemonic)
  - branches from the roots
  - branches from the trunks
    - suprascapular nerve
  - branches from the cords
    - lateral cord
      - lateral pectoral nerve
    - posterior cord
    - medial cord
  - terminal branches
    - ulnar nerve
    - radial nerve
      - posterior interosseous nerve (deep radial nerve)
      - superficial radial nerve
    - musculocutaneous nerve
    - axillary nerve
    - median nerve
      - anterior interosseous nerve
      - bifid median nerve
lymphatic drainage of the upper limb
- axillary lymph nodes

Article information

rID: 844

System: Musculoskeletal

Section: Anatomy

Tag: stub, cases

Synonyms or Alternate Spellings:

AC joint configuration

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