Characteristics

• Common in the elderly osteoporotic population following a fall onto the outstretched hand.

• In the general population requires a more significant force, unless metastatic deposits are present in the proximal humerus.

• Depending on the forces applied, dislocation can occur concomitantly.

• Classified by Neer depending on the number and displacement of segments. The four segments described are: head, greater tuberosity, lesser tuberosity and shaft. Displacement is defined as separation of > 1 cm or > 45 degrees of angulation.

Clinical features

• The patient will complain of pain and be reluctant to move the arm, often supporting the elbow with the contralateral hand.

• Deformity may be present with associated bruising and/or fracture crepitus.

• Check and document axillary-nerve sensorimotor function – look/feel for a flicker of isometric deltoid contraction by asking the patient to try and abduct their arm, but with the examiner's hands stabilising the humerus so no movement occurs, thus minimising pain.

Radiological features

• AP gleno-humeral joint and axillary view is the best combination; however in the acute situation a Velpeau view (oblique axial view with the patient leaning backwards over the film and the arm abducted, e.g. holding an i.v. pole on the trolley) is far more useful than a lateral scapular ‘guessogram’.

• Fracture line should be assessed according to Neer's classification.

• A lipo-haemarthrosis may be visible as a fat/fluid level inferior to the acromium.

• A significant haemarthrosis may displace the humeral head downwards resulting in a pseudo-subluxation – this is exacerbated by the lack of deltoid tone to minimise pain.

• Look for associated dislocation (anterior or posterior) – best seen on the axial/axillary view – look for the corAcoid to orient Anterior.