Correct plate position
The correct plate position is:
about 5-8 mm distal to the top of the greater tuberosity
aligned properly along the axis of the humeral shaft
slightly posterior to the bicipital grove (2-4 mm)
Confirmation of correct plate position
The correct plate position can be checked by palpation of its relationship to the bony structures and also confirmed by image intensification.
To confirm a correct axial plate position insert a K-wire through the proximal hole of the insertion guide. The K-wire should rest on the top of the humeral head.
Pitfall 1: plate too close to the bicipital groove
The bicipital tendon and the ascending branch of the anterior humeral circumflex artery are at risk if the plate is positioned too close to the bicipital groove. (The illustration shows the plate in correct position, posterior to the bicipital groove).
Pitfall 2: plate too proximal
A plate positioned too proximal carries two risks:
- The plate can impinge the acromion
- The most proximal screws might penetrate or fail to securely engage the humeral head