Authors of section

Authors

Martin Jaeger, Frankie Leung, Wilson Li

Executive Editors

Peter Trafton

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Safe zones in the proximal humerus

1. Anatomy

Neurovascular structures

The course of the following neurovascular structures should be kept in mind:

  • Axillary nerve
  • Cephalic vein
  • Anterior circumflex humeral artery
  • Ascending branch of the anterior circumflex humeral artery
  • Posterior circumflex humeral artery
  • Musculocutaneus nerve
Neurovascular structures

Tendon of the long head of the biceps

Another important structure is the tendinous origin of the long head of the biceps, which runs anteriorly and is usually palpable. Make sure not to fix this structure to the bone with pins or K-wires.

Tendon of the long head of the biceps

2. Safe zones

Axillary nerve

The anterior motor branch of the axillary nerve crosses the humerus horizontally about 6 cm distal to the lateral border of the acromion. This distance does not significantly vary and is reliable.
To protect the axillary nerve mark the skin 5 cm and 7 cm distally to the acromion. This marks the corridor in which the axillary nerve is at risk.

The lateral aspect of the proximal humerus, proximal and distal to this corridor can be regarded as a safe zone.

Axillary nerve

3. Pin insertion

Safe zones for pins

Pins are inserted from lateral (alternatively from anterolateral or posterolateral) through the deltoid muscle.

Pins are inserted from lateral (alternatively from an anterolateral or posterolateral) through the deltoid muscle.

The tips of the pins in the humeral shaft should just perforate the far cortex. If inserted too deeply, they can injure the neurovascular bundle.

The tips of the pins in the humeral shaft should just perforate the far cortex.