MedSchool: Ace Your OSCEsThe Medical Company
GET - On the App Store
Ortho X-Ray

Joint Position

February 15th, 2021


  • Look For

    Joint disassociation.
  • Shoulder - anterior / posterior / inferior
  • Finger - interphalageal / metacarpophalangeal
  • Elbow - posterior / posterolateral / posteromedial
  • Patella - lateral / medial
  • Hip - posterior / anterior
  • Wrist - lunate / perilunate
  • Interpretation

  • Simple - dislocation without fracture
  • Complex - dislocation with fracture of any of the bones involved

Shoulder Dislocation

  • Look For

  • Disassociation of the humeral head from the glenoid.
  • Interpretation

  • Anterior dislocation (95%) - anterior, medial and inferior displacement of the humeral headForced extension + abduction + external rotation, direct trauma from behind
  • Posterior dislocation (4%) - posterior displacement of humeral head on axillary viewForced contraction of shoulder muscles
  • Inferior dislocation (1%) - inferior displacement of humeral headForced abduction
In the case of anterior dislocation, look for the associated Bankart lesion (detachment of anterior labrum) and Hill-Sachs lesion (impacted posterolateral humeral head fracture).

Elbow Dislocation

  • Look For

  • Dislocation of the elbow joint - most commonly posterior, though may be posterolateral, posteromedial, lateral or medial.
  • Fracture of the radial head, olecranon or coronoid process.

Hip Dislocation

  • Look For

  • Disassociation of the femoral head from the acetabulum.
  • Interpretation

  • Posterior dislocation (90%) - posterior, superior and lateral displacement of the femoral headAxial load onto flexed hip (e.g. dashboard injury)
  • Anterior dislocation (10%) - anterior displacement, with the femoral head lying either superior (pubic) or inferior (obturator) to the acetabulum.Direct trauma while in abduction and external rotation

Patellar Dislocation

  • Look For

  • Displacement of the patella. Most commonly lateral, though may be medial.
Next Page
Want more info like this?
  • Your electronic clinical medicine handbook
  • Guides to help pass your exams
  • Tools every medical student needs
  • Quick diagrams to have the answers, fast
  • Quizzes to test your knowledge
Sign Up Now

Snapshot: Initialising...