Anterior Approach to Humerus Shaft

Anterior Approach to Humerus Shaft is used to treat the following conditions:

1. Open reduction and internal fixation of humerus shaft fractures.
2. Humeral tumor biopsy/resection.
3. Humeral osteotomy.
4. Treatment of osteomyelitis.

Position of the Patient

• Place the patient supine on the operating table, with the arm on an arm board, abducted about 60 degrees.

Landmarks and Incision

• Landmarks:
  1. The Coracoid process.
  2. The long head of the biceps brachii muscle.
• Incision:
  1. Make a curved incision from the tip of the coracoid process distally in line with deltopectoral groove along the lateral aspect of the humerus.
  2. Incision should be stopped approximately 5 cm above the flexion crease of the elbow (lateral antebrachial cutaneous nerve is at risk here).

Internervous plane

Proximally the Internervous plane in Anterior Approach to Humerus Shaft lies between:

1. Deltoid muscle which is innervated by the the axillary nerve.
2. Pectoralis major muscle which is innervated by the the medial and lateral pectoral nerves.

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Distally the Internervous plane in Anterior Approach to Humerus Shaft lies between:

1. Medial brachialis muscle which is innervated by the the musculocutaneous nerve.
2. Lateral brachialis muscle which is innervated by the the radial nerve.

Superficial dissection

• Identify the cephalic vein – can be taken medially or laterally.
• Proximally, develop the interval between the deltoid and pectoralis major muscle.
• Distally, incise the deep fascia of the arm in line with the skin incision.
• Identify the interval between the biceps muscle and brachialis muscle:
  • Biceps muscle can be retracted medially or laterally (typically it’s taken medially).

Deep dissection

• Proximally, incise the periosteum lateral to the pectoralis major tendon insertion, staying lateral to the long head of the biceps tendon:
  • The anterior humeral circumflex artery is seen here and must be ligated.
• Distally, the fibers of the brachialis are split longitudinally along the midline to expose the periosteum and humeral shaft.

Approach Extension

• Proximal Extension:
  • Because the anterior approach uses the deltopectoral interval, its upper end can be modified easily into an anterior approach to the shoulder (Deltopectoral approach).
• Distal Extension:
  • The anterior approach to humerus shaft cannot be extended distally.

Dangers

Structures at risk during anterior approach to humerus include:

1. Anterior circumflex humeral artery:
   • The Anterior circumflex humeral artery is at risk proximally between the pectoralis major and deltoid muscles.
2. Axillary nerve:
   • The Axillary nerve can be injured with vigorous retraction of the deltoid.
3. Radial nerve:
   • The Radial nerve must be identified before any incision is made into the brachialis muscle or before periosteal elevation of the brachialis muscle off the humerus occurs.
   • It’s also at risk on the middle 1/3 of the humerus where it lays in the spiral groove on the posterior humerus.

References

• Surgical Exposures in Orthopaedics book – 4th Edition
• Campbel’s Operative Orthopaedics book 12th