Deltopectoral Approach: Comprehensive Surgical Anatomy & Clinical Applications
Key Takeaway
The deltopectoral approach is a key anterior shoulder surgical route. It navigates the interval between the deltoid and pectoralis major. Critical anatomical landmarks include the cephalic vein in the groove, the coracoid process, and deep structures like the axillary neurovascular bundle and subscapularis muscle. Understanding these, especially the axillary nerve, ensures safe, effective orthopedic procedures.
A 72-year-old female presents with a 3-part proximal humerus fracture. You are preparing to perform an Open Reduction and Internal Fixation (ORIF). Describe the anatomical landmarks and the step-by-step development of the deep interval using the deltopectoral approach. Mention the specific risks associated with retraction.
Candidate: I would identify the coracoid process and the deltopectoral groove. I would incise the skin and subcutaneous fat, identify the cephalic vein, and retract it medially with the pectoralis major. Then, I would incise the clavipectoral fascia, identify the conjoined tendon, and retract it medially to access the subscapularis. I would watch out for the axillary nerve and the musculocutaneous nerve during retraction.
Candidates often fail to explicitly mention the "internervous plane" concept. They frequently forget the specific danger to the musculocutaneous nerve (entering the coracobrachialis 5-8cm distal to the coracoid) and fail to protect the axillary nerve/anterior circumflex vessels via a Hohmann retractor placed under the inferior border of the subscapularis.
The candidate should structure the response: 1. Landmarks: Coracoid, deltopectoral groove. 2. Interval: Internervous plane (Axillary N. vs Pectoral Ns.). 3. Cephalic Vein: Retract medially to protect from axillary nerve/deltoid damage. 4. Clavipectoral Fascia: Longitudinal incision medial to the conjoined tendon. 5. Deep Protection: Emphasize using a blunt Hohmann retractor under the inferior border of the subscapularis to shield the axillary nerve/anterior humeral circumflex artery. Mention the musculocutaneous nerve at risk from excessive medial traction of the conjoined tendon.
During the deep dissection for a shoulder arthroplasty, you encounter dense scarring in the deltopectoral interval from a previous procedure. What is your strategy for safely continuing the approach, and how does this affect your management of the subscapularis?
Candidate: I would proceed with extreme caution, using sharp dissection rather than blunt, to avoid damaging the cephalic vein or the underlying axillary structures. If the subscapularis is heavily scarred, I would consider a lesser tuberosity osteotomy instead of a standard tenotomy to ensure a strong repair site.
Failing to mention the possibility of proximal control or the risk of nerve injury in the setting of fibrosis. A poor candidate might persist with blunt, forceful dissection, which is the most common cause of iatrogenic injury in revision shoulder surgery.
The ideal response: 1. Proximal-to-Distal Dissection: Start in an area where the interval is less scarred. 2. Sharp Dissection: Use surgical blades or tenotomy scissors instead of blunt digital dissection. 3. Vascular Vigilance: Be prepared for the cephalic vein to be obliterated or difficult to identify. 4. Subscapularis Plan: Discuss the pivot from tenotomy to a subscapularis "peel" or a lesser tuberosity osteotomy if the tendon tissue is compromised by adhesions, ensuring the final repair is bone-to-bone or at least into a robust bed.
