Humeral Interlocking Nailing Procedure for Proximal Shaft Fractures
Intramedullary nailing is the preferred treatment for proximal humeral shaft fractures, providing excellent pain relief and functional outcomes with minimal complications. 1
Preoperative Assessment
- Comprehensive evaluation of fracture pattern and displacement using radiographs and potentially CT scans 1
- Assessment of metastatic disease in other bones if pathologic fracture is suspected 1
- Evaluation of patient's life expectancy, mental status, mobility status, pain level, metabolic status, skin condition, and nutritional status 1
Surgical Technique
Patient Positioning and Preparation
- Position patient in beach chair or supine position with affected shoulder elevated 2
- Prepare and drape the entire upper extremity to allow full manipulation during the procedure 2
- Ensure C-arm fluoroscopy is available and properly positioned 3
Surgical Approach
- Make a 3-5 cm anterolateral incision starting at the anterolateral corner of the acromion 2
- Split the deltoid fibers longitudinally in line with its muscle fibers 2
- Identify and make a longitudinal incision in the rotator cuff (supraspinatus tendon) 2
Entry Point Establishment
- Locate the entry point at the apex of the humeral head, slightly medial to the greater tuberosity 2
- Use an awl to create the initial entry portal 2
- Insert a guidewire under fluoroscopic guidance 2
- Ream the proximal humerus over the guidewire to accommodate the nail diameter 2
Fracture Reduction
- Perform closed reduction of the fracture under fluoroscopic guidance 4
- If closed reduction fails, consider limited open reduction through a separate incision 4
- Maintain reduction while advancing the guidewire across the fracture site into the distal fragment 4
Nail Insertion
- Select appropriate nail length and diameter based on preoperative planning 4
- Mount the nail on the insertion jig 4
- Insert the nail over the guidewire through the entry portal 4
- Advance the nail across the reduced fracture site into the distal fragment under fluoroscopic control 4
- Ensure proper depth of the nail with its proximal end slightly buried below the articular surface 4
Proximal Locking
- Insert at least two proximal locking screws through the jig into the humeral head 5
- Ensure proper positioning of screws to avoid articular penetration 5
- Consider additional oblique screws for better proximal fragment fixation in osteoporotic bone 5
Distal Locking
- Perform distal locking using the targeting device or freehand technique under fluoroscopic guidance 3
- While some studies suggest that distal locking may be omitted in certain stable fracture patterns, bipolar locking (both proximal and distal) is generally recommended for optimal stability 3
- Use at least one distal locking screw to prevent rotation and provide axial stability 3
Closure
- Repair the rotator cuff with non-absorbable sutures 2
- Close the deltoid split and subcutaneous tissue 2
- Close the skin with appropriate sutures or staples 2
Postoperative Management
- Immobilize the arm in a sling for comfort 4
- Begin passive range of motion exercises within the first week 4
- Progress to active-assisted and active range of motion exercises as tolerated 4
- Avoid heavy lifting for 8-12 weeks until radiographic evidence of healing 4
Expected Outcomes and Complications
Outcomes
- Fracture healing typically occurs within 2-3 months 4
- Good functional outcomes with mean Constant scores of 65-89 depending on fracture complexity 4, 6
- Earlier return to function compared to conservative management 2
Potential Complications
- Rotator cuff dysfunction due to surgical approach 2
- Screw back-out (reduced with newer nail designs) 4
- Iatrogenic fracture during nail insertion 2
- Nonunion or delayed union (rare, approximately 3-5%) 4
- Avascular necrosis in complex fractures involving the humeral head 4
Special Considerations
- For pathologic fractures, cement augmentation may provide additional stability and pain relief 1
- In elderly patients with poor bone quality, additional fixation techniques may be necessary 1
- Consider reverse shoulder arthroplasty instead of nailing for complex proximal humeral fractures with pre-existing rotator cuff dysfunction 1