Anterior portal selection for shoulder arthroscopy.

A posterior portal site has become the accepted standard for introduction of the arthroscope for routine diagnostic procedures of the shoulder. Few published guidelines exist, however, on the optimum and safe positions of accessory portals for introduction of a probe or surgical instruments during shoulder arthroscopy. The relatively thick surrounding muscle layers and the close proximity of vital neurovascular structures would make guidelines for safer and more reproducible accessory portal selection helpful to minimize the risk of injury to these structures. The "intraarticular triangle" bounded by the humeral head, the glenoid rim, and the biceps tendon has been found to be an excellent intraarticular landmark for placement of an accessory anterior portal for shoulder arthroscopy. Anatomical dissections on 20 cadaver shoulders have confirmed that instruments passed through this location are at little risk to injure adjacent neurovascular structures about the shoulder. Clinical data in 30 shoulder arthroscopies performed utilizing this landmark for placement of an anterior portal have confirmed this position to be a safe and useful location for portal placement if proper precautions are followed.