02/06/2026
Open Reduction and Internal Fixation (ORIF) utilizing the Proximal Humerus Internal Locking System (PHILOS) plate is a standardized surgical strategy for managing complex proximal humerus fractures.
AO Foundation Surgery Reference
PHILOS
ORIF - Plate fixation for 4-Part, marked displacement ...
Surgical Approaches
1. Deltopectoral Approach
This is the standard, most frequently chosen approach due to its versatility and safety profile.
Incision: Starts at the coracoid process, extending distally along the deltopectoral groove toward the deltoid insertion.
Superficial Dissection: The cephalic vein is identified and typically retracted laterally with the deltoid muscle.
Deep Dissection: The clavipectoral fascia is incised lateral to the conjoined tendon to reveal the humeral head.
Nerve Protection: The musculocutaneous nerve (medial) and axillary nerve (distal/deep) must be protected by avoiding aggressive or blind retraction.
AO Foundation Surgery Reference
2. Anterolateral Delta-Splitting Approach
Commonly utilized for isolated greater tuberosity fractures or minimally invasive plate osteosynthesis (MIPO).
Incision: Longitudinal incision made downward from the anterolateral tip of the acromion.
Dissection: The deltoid muscle fibers are split bluntly.
Nerve Protection: The axillary nerve courses transversely across the deep surface of the deltoid roughly 5 to 7 cm distal to the acromion tip. The split must not extend past 5 cm without isolating and safeguarding this nerve.
Steps of Fixation
1. Patient Positioning and Setup
The patient is placed in a beach-chair position with the torso elevated roughly 60°. The affected arm must be draped completely free to permit unimpeded intraoperative fluoroscopy (C-arm) tracking in both anteroposterior and axial planes.
2. Fracture Reduction and Temporary Fixation
Heavy traction sutures (e.g., #2 braided non-absorbable suture) are anchored into the insertions of the supraspinatus, infraspinatus, and subscapularis tendons to establish control over displaced tuberosity fragments.
The main humeral head fragment and shaft fragments
Smooth Kirschner wires (K-wires) are driven provisionally across the fracture lines to temporarily freeze the reduction without blocking where the plate will rest.
3. Plate Positioning
The PHILOS plate is tucked onto the lateral cortex of the humerus, immediately lateral (approx. 2–4 mm) to the bicipital groove hosting the long head of the biceps tendon.
The top boundary of the plate must sit at least 8 mm distal to the superior border of the greater tuberosity. Placing the plate too high triggers subacromial impingement; placing it too low prevents proper proximal screw distribution.
A temporary K-wire is fed through the specialized proximal guide hole on the aiming jig to verify height and trajectory via fluoroscopy.
4. Humeral Shaft Fixation
A standard, non-locking 3.5 mm cortical screw is driven into the elongated (compression) hole of the plate shaft.
This allows fine-tuning adjustments to the height and axial rotation of the plate before committing to permanent locking screws.
5. Humeral Head Locking Screw Insertion
The dedicated radiolucent PHILOS aiming jig and drill sleeves are attached directly to the plate.
Crucial locking holes are drilled using a calibrated 2.8 mm drill bit.
Screw depth is verified with a depth gauge, taking care to feel for solid subchondral bone without penetrating into the glenohumeral joint space.
Multiple 3.5 mm locking screws are fully seated into the humeral head to build a rigid, angular-stable scaffold. Special emphasis is placed on inserting inferior calcar screws to prevent varus collapse of the construct.
6. Final Shaft Fixation and Rotator Cuff Suturing
The remaining holes in the distal shaft are filled with 3.5 mm locking cortical screws to secure the construct to the diaphysis.
The initial traction sutures previously placed in the rotator cuff tendons are pulled through the perimeter suture eyelets of the PHILOS plate and tied down. This neutralizes the muscle pull and structurally reinforces the tuberosity fixation.
7. Final Verification and Closure
All temporary K-wires are removed. The shoulder is cycled through a passive range of motion under fluoroscopy to confirm absolute mechanical stability, lack of subacromial impingement, and that no screws have breached the joint cartilage. The surgical wound is irrigated and closed in anatomic layers.
