肩関節鏡視下手術における後方から前方へのカニューレ誘導テクニックを用いた関節下腔へのアクセス

Accessing the subacromial space remains a fundamental yet challenging step in shoulder arthroscopy, particularly during rotator cuff repair. Limited space, bursitis, and adjacent tissue inflammation often complicate visualization and scope advancement. This technical note presents a reproducible and efficient 2-portal technique for subacromial access using a metal arthroscopic sheath, trocar, and rigid cannula. The procedure begins with creation of a standard posterior portal through which the sheath is advanced beneath the acromion using wrist-guided flexion-extension to identify anatomic landmarks. The sheath is then passed lateral to the coracoacromial ligament and retrieved from the anterior portal under direct visualization. A 6.0-mm cannula is introduced into the rotator interval and used as a working channel for the arthroscope, enabling controlled navigation beneath the acromion. This approach allows for immediate identification of key anatomic structures, including the coracoacromial ligament, and facilitates bursal debridement and subacromial procedures without additional portals. The technique minimizes iatrogenic risk, preserves anatomic integrity, and enhances visualization through triangulation. By avoiding unnecessary instrumentation and simplifying scope trajectory, this method contributes to surgical efficiency and safety during subacromial shoulder arthroscopy.