What is the detailed step‑by‑step surgical technique for open reduction and internal fixation (ORIF) with a proximal humeral locking plate for a displaced surgical‑neck humerus fracture in an adult?

Surgical Technique for ORIF with Locking Plate Fixation of Displaced Surgical Neck Humerus Fractures

Open reduction and internal fixation using a proximal humeral locking plate via the deltopectoral approach is the standard surgical technique for displaced surgical neck fractures in adults when joint preservation is desired, with specific attention to medial support restoration and adequate locking screw purchase in the humeral head to prevent complications. 1

Preoperative Planning

• Assess fracture complexity and patient age carefully, as complications including screw cutout occur in 43% of patients over 60 years with 3 or 4-part fractures 2
• Evaluate the posteromedial metaphyseal extension and medial hinge integrity, as these are the most important predictors of outcomes 1
• Consider that calcar length <8mm and disruption of the medial hinge increase risk of complications, though anatomic reduction can maintain humeral head perfusion even in complex fractures 1

Surgical Approach

Incision and Exposure

• Make a 12-14 cm incision along the deltopectoral groove 1
• Develop the interval between the deltoid (laterally) and pectoralis major (medially) 1
• Identify and protect the cephalic vein (typically retract laterally with deltoid) 1

Fracture Reduction

Key Reduction Principles

• Achieve anatomic reduction of the fracture fragments, as varus malreduction is the primary contributor to loss of fixation and technical complications 1
• Restore the medial calcar support, which is critical to prevent screw cutout and improve functional outcomes 1
• Use provisional fixation with K-wires and heavy non-absorbable sutures through the rotator cuff tendons to maintain reduction 1

Reduction Sequence

• Reduce the humeral head to the shaft first, correcting any varus or valgus deformity 3
• Restore the medial hinge and calcar continuity 1
• Reduce and provisionally fix any tuberosity fragments 1
• Place tension sutures through the rotator cuff insertions on the tuberosities for additional stability 3, 1

Plate Application and Fixation

Plate Positioning

• Position the proximal humeral locking plate 5-8mm distal to the superior aspect of the greater tuberosity to avoid subacromial impingement 3
• Ensure the plate sits flush against the lateral cortex of the proximal humerus 3
• Verify plate position with intraoperative fluoroscopy in AP, lateral, and axillary views 3

Screw Fixation Strategy

• Use adequate locking screws in the humeral head (minimum 6-8 screws) to achieve sufficient purchase in often osteoporotic bone 3
• Place unicortical locking screws in the metaphysis of the proximal humerus, ensuring screws are positioned in multiple planes for optimal stability 1
• Insert bicortical non-locking or locking screws in the humeral shaft (typically 3-4 screws) 1
• Verify all screws are subchondral but do not penetrate the articular surface using multiple fluoroscopic views, as screw cutout occurs in 23% of cases overall and 43% in patients over 60 2
• Measure screw length carefully, as improper screw length contributes to technical complications 1

Augmentation Techniques

• Consider bone graft or bone graft substitutes when there is metaphyseal comminution or poor bone quality to provide medial support 3
• Suture the rotator cuff tendons through the open suture holes in the plate to augment fixation and assist with fracture reduction 3, 1
• These rotator cuff sutures provide additional stability and help maintain reduction 3

Intraoperative Fluoroscopy

• Use sufficient intraoperative fluoroscopic imaging throughout the procedure to verify reduction, plate position, and screw placement 3
• Obtain AP, lateral scapular, and axillary views to confirm no intra-articular screw penetration 3
• Check for restoration of neck-shaft angle (normal approximately 130-140 degrees) 4
• Verify medial calcar restoration on AP view 1

Wound Closure

• Suture the rotator cuff to the plate if not already done during fixation 1
• Close the deltopectoral interval (typically the interval is not formally closed) 1
• Close subcutaneous tissue and skin in layered fashion 1

Critical Technical Pitfalls to Avoid

• Varus malreduction is the most common technical error and leads to loss of fixation - always verify anatomic alignment intraoperatively 1
• Inadequate locking screw purchase in the humeral head increases risk of screw cutout, especially in elderly patients 2
• Improper plate positioning (too proximal causes impingement, too distal reduces screw options in head) 3
• Failure to restore medial support increases complications and decreases functional outcomes 1
• Intra-articular screw penetration occurs when fluoroscopic views are inadequate 3

Expected Outcomes and Complications

• Fracture healing occurs in 98% of cases by 6 months 2
• Be aware that radiographic complications occur in 36% of patients overall, with significantly higher rates (57%) in patients over 60 years 2
• Screw cutout with intra-articular displacement occurs in 23% overall and 43% in patients over 60 2
• Postoperative stiffness occurs in 24% and is the most common reason for reoperation 5
• Survivorship until any reoperation is 74% at 10 years, but 90% when reoperations for stiffness are excluded 5
• Despite complications, long-term patient satisfaction and functional outcomes are good to excellent when proper technique is followed 5