CORR Insights®: What Are Practical Surgical Anatomic Landmarks and Distances from Relevant Neurologic Landmarks in Cadavers for the Posterior Approach in Shoulder Arthroplasty?

Before reading the study by Bahk and Greiwe [¹] in this month’s Clinical Orthopaedics and Related Research®, I wondered why we would modify or change the deltopectoral surgical approach for shoulder arthroplasty when it works so well. After reading the study, I reflected on the advantages, challenges, and potential complications of the deltopectoral approach. While this technique offers great exposure for the glenoid and the humerus for shoulder arthroplasty, to accommodate for this exposure, one of three things must occur with the subscapularis tendon: tenotomy, “peel”, or lesser tuberosity osteotomy (LTO).

Addressing the subscapularis tendon generally involves performing a tenotomy while also reapproximating the tendon to itself or the “peel technique,” which involves taking down both the capsule and tendon from the lesser tuberosity and reapproximating them through drill holes medial to the lesser tuberosity. In essence, we are medializing the tendon and improving external rotation. But those procedures come with a cost—anterior escape, which is caused by a lack of healing. That being said, the LTO technique was developed to be biomechanically stronger with bone-to-bone healing, and studies show [^2-5] that healing rates do improve over the peel and tenotomy approaches. However, we are still left with a group of both nonunions (13%) and displacement of the osteotomy (7%), leading to the dreaded anterior escape and poor clinical outcomes with pain and bad shoulder mechanics in patients who undergo shoulder arthroplasty [^2-5].

In the current study, Bahk and Greiwe [¹] investigated a novel posterior approach for shoulder arthroplasty and noted the advantages, namely the avoidance of the subscapularis, which is an important anterior stabilizer for shoulder arthroplasty. In the standard deltopectoral anterior approach, the subscapularis must be violated either through the “peel” technique, tenotomy, or LTO. But these methods can potentially lead to instability and a poor clinical outcome. Additionally, the study details the anatomic landmark of importance for the posterior approach in shoulder arthroplasty, which is a more feasible approach for those surgeons less unfamiliar with the posterior structures of the shoulder.

By considering these two major points during the surgical decision-making process, one can anticipate (or predict) a more reproducible clinical outcome and decrease complication rate for both anatomic total shoulder arthroplasty or reverse total shoulder arthroplasty.