Hip fracture fixation (dynamic hip screw)

Why are we operating?

Fixation of an intertrochanteric hip fracture with a sliding screw-and-plate that lets the fracture compress as the patient walks on it, the fracture-clinic operation most on-call students will see first.

Indication: Stable intertrochanteric (extracapsular) fractures of the proximal femur; the femoral head keeps its blood supply, so it is fixed, not replaced.

The operation in 4 steps

1. 01Reduction on the traction table

   On the traction table under image intensifier, the fracture is reduced closed with traction and rotation, checked on two views before anything is opened.

   Why: The implant holds a reduction; it does not create one. Alignment on both AP and lateral views before draping is the operation's real first fixation.

2. 02Lateral approach

   A lateral incision over the proximal femur, through fascia lata, splitting vastus lateralis or lifting it forward to expose the lateral cortex below the greater trochanter.

   Why: The lateral femur is the safe workshop of hip surgery: no major vessels or nerves cross it, and the flat cortex there is exactly where the plate is designed to sit.

3. 03Guidewire and lag screw

   A guidewire is passed up the femoral neck into the centre of the head on both views, the tip-apex distance measured, and the lag screw placed over the wire to within millimetres of the joint.

   Why: The tip-apex distance, the combined distance from screw tip to the apex of the head on both views, is the single best predictor of failure: keep it under about 25 mm and cut-out becomes rare. Centre-centre is the whole game.

4. 04Plate, compression and closure

   The plate is fixed to the lateral cortex over the screw's barrel, controlled compression applied across the fracture, and the wound closed in layers over the fascia.

   Why: The 'dynamic' in the name is the barrel: the screw can slide back through the plate as the patient loads the leg, letting the fracture impact and compress, the implant recruits walking itself as the treatment.

Anatomy you need

The proximal femur between trochanters, where these fractures run, and the neck and head the lag screw must centre through.

What can go wrong

• Venous thromboembolism

  Unilateral leg swelling, or sudden dyspnoea, pleuritic pain, tachycardia, sometimes the only sign is unexplained hypoxia.

• Surgical-site infection

  Wound erythema, warmth, discharge, and pain out of proportion, typically from postoperative day 4–7.

• Postoperative bleeding

  Tachycardia first, hypotension late; falling urine output; a distending abdomen or rising drain output.