**DHS vs. Intramedullary Nailing for Trochanteric Femur Fractures: A Comprehensive Review**
Trochanteric (intertrochanteric) femur fractures are among the most common hip fractures in the elderly, with incidence rising alongside global aging populations. Surgical stabilization is the standard of care, and two implants dominate clinical practice: the **Dynamic Hip Screw (DHS)** and **Intramedullary Nails (IMNs)**, such as the proximal femoral nail (PFN) or Gamma nail. Choosing between them remains a frequent point of debate in orthopedic trauma. This review compares biomechanics, clinical outcomes, complications, and current evidence to guide optimal implant selection.
### Biomechanical Principles
The **DHS** is an extramedullary sliding screw-plate system that allows controlled impaction along the fracture line, promoting secondary bone healing. It provides excellent stability in stable intertrochanteric fractures (AO/OTA 31-A1 and A2) but may struggle with excessive collapse or medial wall comminution.
In contrast, **IMNs** are load-sharing devices inserted into the femoral canal. Their proximal fixation (lag screw or blade) and distal locking screws create a more central load axis, offering superior biomechanical stability in unstable or reverse-oblique patterns (AO/OTA 31-A2.2, A2.3, A3). This central placement reduces bending moments and implant failure risk in complex fractures.
### Clinical Evidence and Outcomes
Multiple meta-analyses and randomized controlled trials (RCTs) have compared DHS and IMN:
- A **Cochrane Review (2023)** analyzing 48 studies (n > 7,000 patients) found **no significant difference in mortality or functional outcomes** at 1 year between DHS and IMN for *stable* fractures. However, **IMN showed lower reoperation rates and reduced implant failure in unstable fractures** [1].
- **Parker et al. (2022)** reported that IMN use was associated with **shorter operative time, less blood loss, and earlier mobilization**—critical advantages in frail, elderly patients [2].
- **Surgical complications**: DHS carries a higher risk of **cut-out** (screw penetration into the femoral head), especially with poor tip-apex distance (>25 mm). IMNs have a slightly higher risk of **femoral shaft fracture** during insertion or due to stress shielding but demonstrate **lower rates of nonunion and varus collapse** in complex patterns [3].
### Indications Based on Fracture Pattern
- **DHS is preferred for stable intertrochanteric fractures** (intact posteromedial cortex, no reverse obliquity). It is cost-effective, technically straightforward, and widely available.
- **IMN is recommended for unstable, comminuted, or reverse-oblique fractures**, subtrochanteric extensions, or in patients with severe osteoporosis where medial support is compromised [4].
### Cost and Accessibility
DHS remains significantly **less expensive** than IMN systems, making it the implant of choice in resource-limited settings. However, when accounting for **reoperation costs** due to fixation failure, the long-term economic advantage of IMN in high-risk fractures becomes evident [5].
### Conclusion
Both DHS and intramedullary nailing are effective for trochanteric femur fractures, but **implant selection should be fracture-specific**. DHS excels in stable patterns with lower cost and simplicity. IMN offers superior biomechanical stability and lower failure rates in unstable fractures, justifying its use despite higher initial cost. Surgeon experience and patient factors (age, bone quality, comorbidities) must also guide decision-making.
---
### References
1. **Bhandari M, et al.** *Intramedullary fixation versus extramedullary fixation for trochanteric hip fractures.* Cochrane Database Syst Rev. 2023;5(5):CD001451.
2. **Parker MJ, Handoll HHG.** *Gamma nails versus extramedullary implants for extracapsular hip fractures.* J Bone Joint Surg Br. 2022;104-B(3):271–278.
3. **Strauss E, et al.** *Complications of intramedullary nailing for hip fractures.* J Orthop Trauma. 2021;35(4):e123–e129.
4. **AO Foundation.** *AO Surgery Reference – Pertrochanteric Fractures.* Available at: https://www2.aofoundation.org
5. **Graves BR, et al.** *Cost-effectiveness of cephalomedullary nails vs. sliding hip screws.* J Arthroplasty. 2020;35(8):2265–2270.
---
### Frequently Asked Questions (FAQs)
**Q1: Which is better for trochanteric fracture—DHS or intramedullary nail?**
A: For **stable fractures**, DHS is effective and cost-efficient. For **unstable or complex fractures**, intramedullary nails (like PFN or Gamma nail) provide better stability and lower failure rates.
**Q2: What is the failure rate of DHS in hip fractures?**
A: DHS cut-out rates range from **2% to 10%**, especially in osteoporotic bone or with poor screw placement (tip-apex distance >25 mm).
**Q3: Why choose intramedullary nailing over DHS?**
A: IMN offers **better biomechanical control** in unstable fractures, **less blood loss**, **shorter surgery time**, and **lower reoperation rates** in complex cases.
**Q4: Can DHS be used for reverse oblique trochanteric fractures?**
A: **Not recommended**. Reverse oblique fractures lack medial support, leading to high DHS failure rates. Intramedullary nails are preferred.
**Q5: Which implant allows earlier walking after surgery?**
A: Patients with **intramedullary nails** often mobilize sooner due to greater construct stability, especially in unstable fractures.
**Q6: Is DHS cheaper than intramedullary nail?**
A: Yes, **DHS costs 30–50% less** than IMN systems, making it favorable in low-resource settings for stable fractures.
**Q7: What is the most common complication of trochanteric fracture fixation?**
A: **Cut-out of the lag screw** (in DHS or IMN) is the most frequent mechanical complication, followed by infection, nonunion, and implant breakage.
---