Use the plate as reduction aid
The plate is used as a handle to reduce the humeral head towards the shaft. It must be attached correctly to the humeral head before this is done. Provisional K-wire fixation using K-wire guides can help with this as demonstrated above.
Once preliminary reduction is achieved a bicortical non-locking screw is inserted through the elongated hole. Make sure to insert the screw perpendicular to the humeral shaft.
By tightening this screw in the humeral shaft, the malpositioned humeral head will be aligned to the humeral shaft, thus achieving a correct reduction.
Option: preliminary fracture fixation with K-wires
As an alternative to reducing the fracture with a plate, an open reduction can be performed manually and temporarily secured using 2 K-wires. Make sure to place them from anterior in order to avoid interference with the foreseen plate position.
Confirm proper rotational alignment
Correct rotational alignment must be confirmed. This can be done by matching the fracture configurations on both sides of the fracture. This would be useful in the more transverse fracture configuration as shown in the illustration.
Pearl: check retroversion
The bicipital groove might be a good indicator for correct rotation. In case of correct rotation, no gap/angulation is visible at the level of the fracture.
Remember that the humeral head is normally retroverted, facing approximately 25° posteriorly (mean range: 18°-30°) relative to the distal humeral epicondylar axis. This axis is perpendicular to the forearm with the elbow flexed to 90°.
Confirmation of overall reduction
The correct reduction must be confirmed by image intensification in both AP and lateral views.
Insert additional screws
Insert one or two additional bicortical screws into the humeral shaft. Additional screws might also be inserted into the humeral head.
Supplementary rotator cuff tendon sutures
Secure the tendons of the rotator cuff (subscapularis, supraspinatus, infraspinatus) with additional tension band sutures through the small holes in the plate.
Pitfall: inadequate reduction
A common mistake is inadequate reduction. Residual varus malalignment often results in further (secondary) displacement with varus malunion or fixation failure and possible nonunion.
Final check of osteosynthesis
Using image intensification, carefully check for correct reduction and fixation (including proper implant position and length) at various arm positions. Ensure that screw tips are not intraarticular.
Also obtain an axial view.
In the beach chair position, the C-arm must be directed appropriately for orthogonal views. Position arm as necessary to confirm that reduction is satisfactory, fixation is stable, and no screw is in the joint.