What is the step-by-step procedure for treating an intertrochanteric femur fracture using Dynamic Hip Screw (DHS) plating?

Dynamic Hip Screw (DHS) Plating for Intertrochanteric Femur Fractures: Step-by-Step Surgical Procedure

For stable intertrochanteric fractures, a sliding hip screw (DHS) is the preferred fixation method, while unstable fractures require a cephalomedullary nail instead. 1, 2

Pre-operative Planning and Patient Preparation

Timing and Medical Optimization

• Surgery should be performed within 24-48 hours of admission to optimize outcomes in elderly patients 3, 2
• Administer prophylactic antibiotics within one hour of skin incision to reduce surgical site infections 2
• Administer tranexamic acid at the start of the procedure to reduce blood loss 3
• Implement cardiac output-guided fluid administration, as many patients present hypovolemic 2

Anesthesia Selection

• Either spinal or general anesthesia is appropriate, with spinal anesthesia potentially reducing postoperative confusion in elderly patients 3, 2
• Monitor depth of anesthesia with BIS monitoring to avoid cardiovascular depression 2

Patient Positioning

• Position the patient supine on a fracture table with the affected leg in traction 4
• Apply proper padding to all bony prominences to prevent pressure injuries 3
• Avoid excessive flexion and internal rotation of the non-operative hip to prevent pressure damage 2
• Ensure the C-arm can obtain adequate anteroposterior (AP) and lateral views of the hip 4

Surgical Approach and Exposure

Incision and Dissection

• Make a lateral incision centered over the greater trochanter, extending distally along the femoral shaft (typically 8-12 cm) 4
• Incise the fascia lata in line with the skin incision 4
• Split the vastus lateralis muscle longitudinally or elevate it anteriorly to expose the lateral femoral cortex 4

Fracture Reduction

Reduction Technique

• Achieve anatomic reduction before fixation, as insufficient reduction is a major cause of complications 4, 5
• Under fluoroscopic guidance, reduce the fracture by applying longitudinal traction and internal rotation 4
• Verify reduction quality on both AP and lateral views—the medial cortex should be aligned and the neck-shaft angle restored 6, 5
• Temporarily stabilize the reduction with a bone clamp or K-wires if needed 5
• Ensure proper fixation of the lesser trochanter and posteromedial bone fragments, as these provide critical stability 4

Guide Wire Placement

Wire Positioning

• Insert a guide wire from the lateral femoral cortex, aiming for the center-center or inferior-central position in the femoral head on both AP and lateral views 6, 5
• The guide wire should be positioned in the postero-inferior and central position of the femoral neck and head, as anterior or superior positioning significantly increases cut-out risk 6
• Advance the guide wire to within 5-10 mm of the subchondral bone of the femoral head 6
• Confirm wire position with fluoroscopy before proceeding 5

Common Pitfall: Anterior or superior screw placement produces higher incidence of cut-out failure 6

Lag Screw Insertion

Reaming and Screw Placement

• Measure the guide wire length to determine appropriate lag screw size 4
• Ream over the guide wire using the triple reamer system to create a channel for the lag screw 4
• Insert the lag screw over the guide wire, ensuring it reaches within 5-10 mm of the subchondral bone 6
• Remove the guide wire once the lag screw is fully seated 4
• Verify final screw position fluoroscopically—it should be in the center-center or inferior-central position 6

Barrel Plate Application

Plate Positioning and Fixation

• Slide the barrel plate over the lag screw barrel 4
• Position the plate flush against the lateral femoral cortex 4
• Temporarily secure the plate with a bone clamp 4
• Insert the compression screw into the lag screw barrel to allow controlled sliding 4
• Insert cortical screws through the plate holes into the femoral shaft, ensuring bicortical purchase 4
• Verify that at least 4-6 cortical screws are placed for adequate fixation 4

Technical Note: Avoid breaking the proximal femoral cortex during plate application, as this is a recognized intra-operative complication 4, 5

Final Verification and Closure

Fluoroscopic Confirmation

• Obtain final AP and lateral fluoroscopic images to confirm 4, 5:
  • Anatomic fracture reduction
  • Appropriate lag screw position (center-center or inferior-central)
  • Adequate screw tip-to-subchondral bone distance (5-10 mm)
  • Proper plate positioning and screw purchase
  • No penetration of the femoral head by the lag screw 4

Wound Closure

• Irrigate the wound thoroughly 4
• Close the vastus lateralis and fascia lata in layers 4
• Close the subcutaneous tissue and skin 4
• Apply a sterile dressing 3

Post-operative Management

Immediate Post-operative Care

• Implement active warming strategies to prevent hypothermia 2
• Administer fondaparinux or low molecular weight heparin for DVT prophylaxis, timed between 18:00-20:00 to minimize bleeding risk with neuraxial anesthesia 2
• Continue regular paracetamol throughout the perioperative period for pain management 2
• Use opioids cautiously, especially in patients with renal dysfunction, and avoid codeine due to constipation and cognitive dysfunction risk 2

Mobilization and Weight-bearing

• Implement early mobilization protocols to reduce complications 2
• Avoid too-early weight bearing, as this is a major cause of complications including varus deformity 4
• Weight-bearing status depends on fracture stability and reduction quality 4

Critical Complications to Prevent

Major Complications and Prevention Strategies

• Cut-out phenomenon (lag screw penetrating through femoral head): Prevented by proper screw positioning (inferior-central), adequate reduction, and appropriate weight-bearing restrictions 4, 6, 5
• Varus deformity: Prevented by anatomic reduction, proper lesser trochanter fixation, and controlled weight-bearing 4
• Proximal femoral cortex fracture: Prevented by careful surgical technique during plate application 4, 5
• Infection: Prevented by meticulous sterile technique and appropriate perioperative antibiotics 3, 4
• Avascular necrosis of femoral head: Risk inherent to fracture pattern, minimized by early surgery and atraumatic technique 4, 5

Important Limitation: DHS is not effective for pathologic fractures due to lack of bone healing, particularly with planned subsequent radiation 1