Why does elbow dislocation cause visible deformity after injury?

The elbow depends on matching joint surfaces and supporting ligaments to keep the upper arm and forearm aligned. A dislocation shifts those surfaces, changing the normal angle and contour of the elbow. Swelling and muscle spasm can make the altered outline more noticeable. A dislocation may occur with a fracture, so the appearance alone cannot show which structures are injured. Do not try to compare sides by moving the arm or pushing the joint back.

Keep the arm still in the position found and support it with a sling or padding if this can be done without moving the elbow. Remove rings if swelling is beginning, and arrange emergency medical assessment. Do not eat or drink until assessed if urgent treatment may be needed, and do not attempt reduction at home. Clinicians may use examination and imaging to assess alignment, fractures, blood flow and nerve function.

Visible deformity after an injury needs urgent assessment. Call emergency services if the hand is cold, pale, blue or numb, if fingers are weak, or if pain is severe. Keep checking finger colour and sensation while waiting, without repeatedly moving the elbow.

Ask whether there is a fracture, how alignment will be restored, when movement can begin, and which changes in hand colour, sensation or strength require immediate help.