Shoulder Deltopectoral Approach

Shoulder Deltopectoral Approach (Shoulder Anterior Approach) is used for:

1. Shoulder arthroplasty.
2. Proximal humerus fractures (especially 3 and 4 part fractures).
3. Reconstruction of recurrent dislocations.
4. Long head of the biceps injury.
5. Septic glenohumeral joint.
6. Biopsy and excision of tumors.

Position of the Patient

Beach Chair Position:

• The head is secured in a Mayfield headrest or a commercially available beach chair attachment
• The upper torso is elevated 30 to 60 degrees depending on the procedure performed, can cause transient hypotension.
• The opposite arm, legs, and other prominences are padded and secured The operative shoulder and arm are positioned off the side of the operating table for full access, a bump placed under the ipsilateral scapula may improve access.
• Rotating and tilting the bed away from the operative side can be helpful Commercially available arm holders or positioners may be helpful.

Landmarks and Incision

Landmarks:

1. Coracoid Process.
2. Deltopectoral Groove.

Incision:

Extended Deltopectoral Incision: Typically used for arthroplasty and fracture care A 10- to 15-cm oblique incision is made from just lateral to the coracoid down to the deltoid insertion.

Limited Anterior Incision: Typically used for coracoid bone block transfers or open capsulorrhaphy A 5-cm vertical incision is made in the inferior axillary crease from the coracoid and directed inferiorly toward the axillary fold. Can be extended superiorly for better exposure.

See Also: Glenohumeral Joint

Internervous plane

Internervous plane in Deltopectoral Approach is between:

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

Superficial dissection

Identify and dissect the deltopectoral interval:

• The cephalic vein is the key landmark ,
• Identification may be easier distally, muscle fiber orientation (with the deltoid more vertical and the pectoralis more horizontal), a groove, and perivascular fat may be helpful,
• Typically the vein is more easily dissected free from the pectoralis major, and it is retracted with the deltoid
• Small tributaries should be coagulated,
• Often a large tributary vein from the cephalic crosses the incision at the superior aspect and may need to be suture ligated.

Retract the deltoid laterally and the pectoralis major medially:

• Commercially available self-retaining retractors are useful,
• A superiorly placed retractor above the coracoid can also be useful,
• Make an incision in the clavipectoral fascia lateral to the conjoined tendon,
• Start proximal to the coracoacromial ligament and continue distally to the inferior aspect of the subscapularis tendon,
• The clavipectoral fascia can be identified as the structure that does move when rotating the arm internally and externally.

Deep dissection

• The short head of the biceps (which is supplied by the musculocutaneous nerve) and the coracobrachialis (which is supplied by the musculocutaneous nerve) must be retracted medially before access can be gained to the anterior aspect of the shoulder joint.
• To release them, detach the tip of the coracoid process with an osteotome (The coracoid process must be drilled and tapped before the osteotomy is carried out for later reattachment with a screw).
• The axillary artery is surrounded by the cords of the brachial plexus, which lie behind the pectoralis minor muscle. Abduction of the arm causes these neurovascular structures to become tight and brings them close to the tip of the coracoid and the operative site, so the arm should be kept adducted while work is being done around the coracoid process.
• Retract the coracoid (with its attached muscles) medially. Divide the fascia that fans out from the conjoined tendons of the coracobrachialis and the short head of the biceps on the lateral side of the coracobrachialis because the musculocutaneous nerve enters the coracobrachialis on its medial side.
• Beneath the conjoined tendons lie the fibers of the subscapularis muscle.
• Apply external rotation to the arm to stretch the subscapularis tendon and to protect the axillary nerve as it disappears below the lower border of the muscle.
• Pass a blunt instrument between the capsule and the subscapularis, tag the muscle belly with stay sutures to prevent it from disappearing medially when it is cut and to allow easy reattachment of the muscle to its new insertion onto the humerus. Then divide the subscapularis from its insertion onto the lesser tuberosity of the humerus.
• The capsule is then incised (as needed) to enter the joint.

Approach Extension

Proximal Extension of the Deltopectoral Approach:

• To expose the brachial plexus and axillary artery, and to gain control of arterial bleeding from the axillary artery, extend the skin incision supero-medially, crossing the middle third of the clavicle.
• Next, dissect the middle third of the clavicle subperiosteally and perform osteotomy of the bone, removing the middle third. Cut the subclavius muscle, which runs transversely under the clavicle.
• Retract the trapezius superiorly and the pectoralis major and pectoralis minor inferiorly to reveal the underlying axillary artery and the surrounding brachial plexus.
•  Take care not to damage the musculocutaneous nerve, which is the most superficial nerve in the brachial plexus.

Distal Extension of the Deltopectoral Approach:

• The Deltopectoral Approach can be extended into an anterolateral approach to the humerus.
• Extend the skin incision down the deltopectoral groove, then curve it inferiorly, following the lateral border of the biceps.
• Deep dissection consists of moving the biceps brachii medially to reveal the underlying brachialis, which then can be split along the line of its fibers to provide access to the humerus.

Dangers

These structures are at risk in Deltopectoral Approach:

1. Musculocutaneous nerve:

Musculocutaneous nerve renters medial side of biceps muscle 5-8 cm distal to coracoid (stay lateral), and can have neurapraxia if retraction is too vigorous

2. Cephalic vein:

• Cephalic vein should be preserved if possible; if injured, can be ligated.
• Helpful to be preserved as anatomical landmark in case of revision cases needing same approach

3. Axillary nerve:

• Axillary nerve is at risk with release of subscapularis tendon (runs distal and medial to) or with incision of teres major tendon or latissimus dorsi tendon (runs proximal to).

4. Anterior circumflex humeral artery:

• Anterior circumflex humeral artery runs anteriorly around the proximal humerus cephalad to pectoralis major tendon.

Closure

Depending on the procedure, the capsule and subscapularis are closed separately or together, special care should be taken to reattach the subscapularis to the proximal humerus because detachment can lead to a major iatrogenic problem The deltopectoral interval usually is not closed but is simply allowed to fall back into position. The cephalic vein should be preserved and protected.

References

1. Deltopectoral Approach – AO Foundation
2. Millers Review of Orthopaedics -7th Edition Book.
3. SURGICAL EXPOSURES IN Orthopaedics, The Anatomic Approach. 4th Edition.