What is the preferred method of fixation, Dynamic Hip Screw (DHS) or Proximal Femoral Nailing (PFN), for treating a basicervical fracture of the femoral neck?

Treatment of Basicervical Femoral Neck Fractures: DHS vs PFN

For basicervical femoral neck fractures, either Dynamic Hip Screw (DHS) or cephalomedullary nailing (PFN) can be used with comparable outcomes, though current evidence suggests DHS achieves slightly faster fracture union times while both demonstrate similar rates of fixation failure and reoperation. 1

Understanding Basicervical Fractures

Basicervical fractures occupy a controversial anatomical and treatment zone between true femoral neck fractures and intertrochanteric fractures, representing only 1.8-6.6% of all proximal femoral fractures. 2, 3 The challenge lies in their inherent biomechanical instability despite being extracapsular fractures.

Guideline-Based Framework

The available guidelines do not specifically address basicervical fractures as a distinct entity, which reflects the ongoing controversy about their classification and optimal treatment:

• AAOS guidelines (2022) recommend either sliding hip screw or cephalomedullary device for stable intertrochanteric fractures, with cephalomedullary devices mandatory for subtrochanteric or reverse obliquity patterns. 4

• EULAR/EFORT guidelines (2017) similarly favor sliding hip screw for stable intertrochanteric fractures and cephalomedullary nails for unstable patterns. 4

The critical issue is that basicervical fractures don't fit neatly into either category, creating treatment ambiguity.

Comparative Evidence: DHS vs PFN

Fracture Union

• DHS demonstrates faster union times compared to cephalomedullary nailing, with a mean difference of 0.41 months faster healing (95% CI: -0.70 to -0.12). 1

• In a large prospective series of 269 patients treated with DHS, the average union time was 16.5 weeks (range: 14-24 weeks). 5

Fixation Failure Rates

Both implants show comparable failure rates, which is the most clinically relevant finding:

• Meta-analysis of 353 cases showed no significant difference in cut-out rates (OR: 0.54; 95% CI: 0.10-2.82) or reoperation rates (OR: 0.65; 95% CI: 0.15-2.86) between DHS and cephalomedullary nailing. 1

• DHS fixation in a large series demonstrated only 1.66% nonunion rate and 0.83% screw cutout rate. 5

• However, one trauma center series reported concerning 40% implant failure and 20% reoperation rates with cephalomedullary nails specifically for basicervical fractures. 3

Alternative Consideration: Hemiarthroplasty

For elderly patients with osteoporotic bone, hemiarthroplasty may be underutilized and deserves consideration:

• One series showed 0% fixation failure or reoperation with hemiarthroplasty compared to 40% implant failure with cephalomedullary nails. 3

• This option should be considered particularly in patients over 65 years with poor bone quality or pre-existing hip arthritis, following the same decision-making framework used for displaced femoral neck fractures. 4

Clinical Decision Algorithm

For patients under 65 years with good bone quality:

• Use DHS with anatomic reduction, ensuring lag screw placement within 5-10 mm of subchondral bone. 6
• Achieve fracture union in approximately 16 weeks with low failure rates. 5

For patients with any unstable features (comminution, reverse obliquity, subtrochanteric extension):

• Use cephalomedullary nail instead of DHS, as failure rates exceed 50% with DHS in unstable patterns. 6

For elderly patients (>65 years) with osteoporosis or pre-existing arthritis:

• Consider hemiarthroplasty as primary treatment to avoid fixation failure. 3
• This provides immediate stability and allows full weight-bearing without risk of nonunion. 4

Critical Technical Points

Regardless of implant choice:

• Perform surgery within 24-48 hours of admission. 6
• Achieve anatomic reduction with restoration of medial cortical continuity and normal neck-shaft angle (130-135 degrees). 6
• Avoid preoperative traction, which provides no benefit. 6
• Allow immediate weight-bearing as tolerated postoperatively. 6

Common Pitfalls

• Treating all basicervical fractures as stable intertrochanteric fractures when they may have inherent instability requiring cephalomedullary fixation. 2
• Inadequate reduction before fixation, which leads to malunion and hardware failure. 6
• Over-compression in osteoporotic bone, causing fracture comminution. 6
• Failing to consider arthroplasty in elderly patients, leading to preventable fixation failures. 3