Surgical anatomy of the pectoralis major tendon insertion revisited: relationship to nearby structures and the pectoral eminence for defining the anatomic footprint

BACKGROUND: Intraoperative identification of the normal pectoralis major (PM) footprint can be challenging to identify in the acute and chronic settings. The purpose of this study was to revisit the anatomic footprint of the PM tendon and to determine which nearby landmarks can be used to re-create the normal insertion site during anatomic repair or reconstruction. METHODS: Twenty-one fresh-frozen human cadaveric shoulder specimens were used to define the PM tendon width (ie, superior-to-inferior) and to determine the relationship between the superior aspect of the PM insertion and that of the latissimus dorsi (LD) and anterior deltoid (AD) tendons. An attempt was made to identify potential useful bony landmarks that can be used during anatomic repair or reconstruction of the PM tendon. RESULTS: The mean PM tendon width was 68.8 ± 4.4 mm. The superior margin of the LD insertion was 9.4 ± 5.9 mm above and the AD was 48.4 ± 7.1 mm below the superior margin of the PM tendon insertion, respectively. In 17 of 21 specimens (81%), the superior insertion of the PM tendon attached onto a bony prominence, named the pectoral eminence. CONCLUSIONS: The LD and AD tendon insertions represent reliable soft tissue landmarks for identifying the superior extent of the PM tendon along its bony footprint. The pectoral eminence can also be used as an additional reference point in the majority of cases to facilitate anatomic restoration of the pectoralis tendon during repair and reconstruction. Surgeons should be familiar with the proximity of nearby neurovascular structures when performing PM repairs.