Anterior approach to the humeral shaft

The anterior approach to the humeral shaft is a surgical technique used to address several conditions of the upper arm. This approach provides excellent access for a variety of procedures.

This approach is commonly indicated for:

1. Open reduction and internal fixation of humeral shaft fractures.
2. Biopsy or resection of humeral tumors.
3. Humeral osteotomy.
4. Treatment of osteomyelitis.

Patient Positioning

Position the patient supine on the operating table. Place the affected arm on an arm board and abduct it to approximately 60 degrees.

Landmarks and Incision

Landmarks

• The coracoid process.
• The long head of the biceps brachii muscle.

Incision

Make a curved incision starting at the tip of the coracoid process. Extend it distally in line with the deltopectoral groove, along the lateral side of the humerus. Stop the incision approximately 5 cm above the elbow flexion crease, as the lateral antebrachial cutaneous nerve is at risk in this area.

Internervous Plane

Proximal

The internervous plane for the proximal aspect of this approach lies between:

1. The deltoid muscle, which is innervated by the axillary nerve.
2. The pectoralis major muscle, which is innervated by the medial and lateral pectoral nerves.

Distal

The internervous plane for the distal aspect lies between:

1. The medial brachialis muscle, innervated by the musculocutaneous nerve.
2. The lateral brachialis muscle, innervated by the radial nerve.

Superficial Dissection

Identify the cephalic vein; it can be retracted either medially or laterally.

Proximally, develop the interval between the deltoid and pectoralis major muscles.

Distally, incise the deep fascia of the arm along the line of the skin incision.

Identify the interval between the biceps brachii and brachialis muscles. The biceps muscle can be retracted medially or laterally, though medial retraction is more common.

Deep Dissection

Proximally, incise the periosteum lateral to the insertion of the pectoralis major tendon, staying lateral to the long head of the biceps tendon. The anterior humeral circumflex artery will be encountered here and requires ligation.

Distally, split the fibers of the brachialis muscle longitudinally along the midline to expose the periosteum and the humeral shaft.

Approach Extension

Proximal Extension

Because this approach utilizes the deltopectoral interval, its proximal end can be easily converted into an anterior approach to the shoulder (the deltopectoral approach).

Distal Extension

The anterior approach to the humeral shaft cannot be extended distally.

Dangers

Structures at risk during the anterior approach to the humerus include:

1. Anterior humeral circumflex artery: This vessel is at risk proximally, in the interval between the pectoralis major and deltoid muscles.
2. Axillary nerve: The axillary nerve can be injured by vigorous retraction of the deltoid muscle.
3. Radial nerve: The radial nerve must be identified before any incision into the brachialis muscle or before periosteal elevation of the brachialis from the humerus. It is also at risk in the middle third of the humerus, where it lies within the spiral groove on the posterior aspect of the bone.

References

• Surgical Exposures in Orthopaedics, 4th Edition
• Campbell's Operative Orthopaedics, 12th Edition