Arthroscopic Capsular Release for the Stiff Shoulder

Abstract

The anatomic proximity of several neurovascular structures remains a major concern to the surgeon interested in performing arthroscopic capsular release. We evaluated the anatomic relationships between the released capsule and the axillary nerve, posterior circumflex humeral artery, and brachial artery in a frozen cadaveric model. With the aid of electrocautery, seven cadaveric shoulders underwent complete arthroscopic capsular release. The release was performed circumferentially, approximately 1 cm lateral to the glenoid rim. All shoulders were subsequently frozen and sectioned through the plane of the capsular release while the shoulder was maintained in the lateral arthroscopic position (45 degrees of abduction and 20 degrees of flexion). Anatomic dissection revealed an average distance from the capsular release to the axillary nerve of 7.04 mm (95% confidence interval, 5.62, 8.47), to the posterior circumflex humeral artery of 8.2 mm (95% confidence interval, 6.41, 9.99), and to the brachial artery of 15.97 mm (95% confidence interval, 9.85, 22.09). As the axillary nerve was followed medially from the released capsule, the inferior border of the subscapularis muscle became interposed between the capsule and the axillary nerve. This limited anatomic study shows that a relatively safe margin between the capsule and the neighboring neurovascular structures can be obtained by releasing the capsule within 1 cm of the glenoid rim.

Effect of patient positioning in axillary nerve safety during arthroscopic inferior glenohumeral ligament plication

“…There are some limitations of this study: first, we did not perform any formal power analysis for the study. Twelve shoulders is not a high number, but it was similar to the sample size of other studies [5, 19, 25], so we considered that the current results did not merit further measurements. Second, some of the specimens might present previous capsular alterations such as hyperlaxity; as there is not an easy way to evaluate this in a cadaveric specimen, this was not looked for specifically.…”

Mid-term results following arthroscopic capsular release in patients with primary and secondary adhesive shoulder capsulitis

“…During this part of the procedure, the axillary nerve is of particular concern. However, various cadaveric and arthroscopic studies have shown that the nerve courses within an average of 12 mm from the glenoid and may be kept even safer by an assistant applying traction and abduction [14, 29, 35, 36]. In contrast, other authors have recommended the use of this 360° total capsular release [13, 27].…”

“…The axillary nerve is of particular concern during the inferior capsular release. Previous studies have shown that the nerve runs closer to the humeral insertion than to the glenoidal insertion of the joint capsule; therefore, the distance between the joint capsule and the axillary nerve is greater in abduction than in adduction [14, 36].…”

Treatment Strategy for Frozen Shoulder

“…At this position, the average distance between the axillary nerve and the glenoid rim was 12.4 mm (10 to 25 mm) and the nerve lay at an average of 2.5 mm from the inferior glenohumeral ligament. The abduction-neutral position resulted in the greatest distance between the inferior glenoid and the axillary nerve 7475)…”