ARTHROSCOPIC PORTALS TO THE SHOULDER JOINT: NEUROVASCULAR ELEMENTS AT RISK

Abstract

Introduction and purpose: Different neurovascular structures may be damaged when making arthroscopic portals to the shoulder joint. The description of new portals poses new challenges. The goal of the present study is to provide an update on the anatomic vasculonervous responses of the current approaches to shoulder arthroscopy.

Materials and methods: 16 fresh cadavers were systematically dissected. The most usual arthroscopic portals were marked and, then, the dissection started on a plane-to-plane basis. Relationships were identified and distances were measured to the most important neurovascular elements with a standard caliber (accuracy: 0.5mm).

Results: The portals studied and the structures at risk were the following:

• * Posterior portal: anterior branch of the axillary nerve and posterior circumflex artery 3.4 cm (range: 1.4 – 5); cutaneous branch of the axillary nerve 6.3 cm (range: 3.8 – 8.3), suprascapular nerve 2.8 cm (range: 2.1–3.3).

• * Anterosuperior portal: main branch of the musculocutaneous nerve 6.5 cm (range: 3.8 – 11).

• * Lateral subacromial portal: axillary nerve and posterior circumflex artery 3.7 cm (range: 2– 5.5).

• * Anteroinferior subaxillary portal 4 cm (range: 3.1 –6).

• * Supraspinatus portal: suprascapular nerve 3.2 cm (range: 2.4 – 4).

Conclusions: Although the crucial elements at risk when performing a shoulder arthroscopy are multiple, the axillary and suprascapular nerves were the most vulnerable structures to the different approaches. In spite of the presence of the “safe areas” described above, the neurovascular bundle was frequently affected by passage through the anteroinferior subaxillary portal. The results suggest that the use of this portal is not safe for routine arthroscopic practice.