Dynamic Hip Screw (DHS) Fixation: A Complete Guide

Introduction to Dynamic Hip Screw (DHS) Fixation

Dynamic Hip Screw (DHS) fixation is a widely used surgical procedure to treat intertrochanteric hip fractures, commonly seen in elderly patients after falls. This technique stabilizes the broken bone using a metal screw and plate system, allowing controlled movement to promote healing. Unlike rigid implants, the "dynamic" design lets the bone fragments compress naturally, reducing complications like non-union.

DHS is favored for its high success rate (over 90% in stable fractures) and minimal hardware failure. It’s particularly effective for fractures where the outer side of the femur (trochanter) is damaged. Surgeons often choose DHS over alternatives like intramedullary nails when the fracture pattern permits, as it offers better load-bearing support and preserves bone integrity.

For patients, understanding DHS fixation can ease anxiety about surgery. The procedure typically takes 1–2 hours, with most people walking with assistance within days. Advances in surgical techniques have also reduced recovery times, making DHS a reliable option for regaining mobility.

Indications for DHS Fixation (When is it Needed?)

DHS fixation is primarily recommended for intertrochanteric fractures (between the greater and lesser trochanter) classified as stable or minimally displaced. These fractures often result from low-impact falls in older adults with osteoporosis, where the bone cracks but remains largely aligned.

Key candidates include:

• Elderly patients (60+ years) with fragile bones.
• Active individuals needing quick weight-bearing recovery.
• Cases where the lateral femoral wall is intact (critical for screw stability).

However, DHS is not suitable for:

• Subtrochanteric fractures (below the trochanter).
• Severely comminuted (shattered) fractures.
• Reverse obliquity fractures (unstable patterns).

Early surgical intervention (within 24–48 hours) improves outcomes, reducing risks like bedsores or pneumonia from prolonged immobility.

Preoperative Preparation & Patient Evaluation

Before DHS surgery, a thorough evaluation ensures patient safety and surgical success. This includes:

• Imaging: X-rays and sometimes CT scans to assess fracture type and alignment.
• Blood tests: Check for anemia, infection, or clotting issues.
• Cardiac/pulmonary exams: Vital for elderly patients with comorbidities.

Patients are advised to:

• Fast for 6–8 hours before surgery.
• Stop blood thinners (e.g., aspirin) under medical supervision.
• Arrange post-op support (walkers, caregivers).

Anesthesia options include spinal block (common) or general anesthesia. The surgical team marks the operative leg to avoid errors, and antibiotics are given pre-incision to prevent infection.

Step-by-Step Surgical Procedure of DHS Fixation

1. Positioning: Patient lies supine on a fracture table; the leg is gently tractioned to align bones.
2. Incision: A 10–15 cm cut is made laterally (outer thigh).
3. Bone preparation: A guidewire is inserted into the femoral neck under X-ray guidance.
4. Screw placement: A cannulated lag screw is threaded over the guidewire, compressing the fracture.
5. Plate attachment: A side plate is fixed to the femur with cortical screws.
6. Closure: Layers of tissue are sutured; a sterile dressing is applied.

Fluoroscopy (live X-ray) ensures precise hardware placement. The entire procedure typically takes under 2 hours.

Advantages of DHS Fixation Over Other Methods

Compared to alternatives like intramedullary nailing (IMN) or hemiarthroplasty, DHS offers:

• Lower cost (uses fewer implants).
• Reduced risk of thigh pain (a common issue with IMN).
• Dynamic compression promotes natural bone healing.
• Easier revision if needed.

Studies show DHS has comparable stability to IMN for stable fractures, with fewer intraoperative complications like splintering.

Potential Risks & Complications

While generally safe, DHS risks include:

• Infection (1–3% of cases): Prevented with antibiotics.
• Screw cut-out (5–10%): If osteoporosis is severe.
• Non-union (rare): More likely in smokers or diabetics.

Surgeons mitigate risks by optimizing screw placement and post-op weight-bearing instructions.

Postoperative Care & Rehabilitation

Recovery involves:

• Day 1: Bed rest with leg elevation; pain management.
• Days 2–3: Physical therapy begins (sit-to-stand exercises).
• Week 1: Walking with a walker; stitches removed.

Patients avoid crossing legs or bending past 90 degrees for 6 weeks to prevent dislocation.

Recovery Timeline & Expected Outcomes

Typical milestones:

• 6 weeks: Partial weight-bearing.
• 3 months: Full weight-bearing; return to light activities.
• 6–12 months: Full recovery; hardware rarely needs removal.

90% of patients regain near-normal function with proper rehab.

Frequently Asked Questions (FAQs) on DHS Fixation