High-Yield Summary
- Intertrochanteric fractures require stable fixation to restore early mobility and reduce morbidity; implant choice hinges on fracture stability and patient factors.
- Sliding hip screws (SHS) remain effective for stable, non-comminuted fractures with intact lateral walls.
- Cephalomedullary nails (CMN) offer biomechanical advantages in unstable patterns, reverse obliquityor lateral wall compromise, reducing varus collapse and implant failure.
- Early weight-bearing is generally feasible with both implants but is more reliable with CMN in unstable fractures.
- Surgical decision-making must integrate fracture classification, bone qualityand patient comorbidities to optimize outcomes.
Clinical Fundamentals
Relevant Anatomy
The intertrochanteric region lies between the greater and lesser trochanters, comprising cancellous bone with a rich vascular supply. The lateral femoral cortex, particularly the lateral wall, is critical for implant support and fracture stability. The calcar femorale provides a dense inferomedial buttress essential for load transmission.
Biomechanics
Intertrochanteric fractures disrupt the proximal femoral load-sharing mechanism. The medial cortex resists compressive forces, while the lateral wall counters tensile forces. Implant choice must restore this balance: SHS relies on lateral wall integrity for sliding compression, whereas CMN provides intramedullary load sharing, reducing bending moments and varus deformity risk.
Epidemiology
These fractures predominantly affect elderly osteoporotic patients after low-energy falls. Incidence rises with age and comorbidities, emphasizing the need for prompt fixation to minimize complications such as pneumonia, thromboembolismand decubitus ulcers.
Classification & Diagnosis
| Classification System | Key Features | Impact on Management |
|---|---|---|
| AO/OTA Classification | Types 31-A1 (simple, two-part), 31-A2 (multi-fragmentary), 31-A3 (reverse obliquity, transverse) | Guides implant choice: SHS for A1, CMN preferred for A2 and A3 due to instability |
| Evans Classification | Stable vs. unstable based on posteromedial cortex and lateral wall integrity | Stable fractures suitable for SHS; unstable require CMN or alternative fixation |
| Lateral Wall Integrity | Intact vs. compromised lateral wall (>20.5 mm thickness considered intact) | Intact lateral wall favors SHS; compromised lateral wall mandates CMN to prevent collapse |
Diagnostic Pearls
- Obtain AP and lateral hip radiographs; consider CT for complex or ambiguous patterns.
- Assess lateral wall thickness on AP view; <20.5 mm predicts instability.
- Beware of underestimating comminution on plain films; intraoperative fluoroscopy aids real-time assessment.
Decision-Making Algorithm
Non-Operative vs. Operative Management
Non-operative treatment is reserved for non-ambulatory patients with prohibitive surgical risk or minimal displacement. Operative fixation is standard for ambulatory patients to restore function and reduce complications.
Implant Selection Criteria
| Criteria | Sliding Hip Screw (SHS) | Cephalomedullary Nail (CMN) |
|---|---|---|
| Fracture Stability | Stable (AO 31-A1), intact lateral wall | Unstable (AO 31-A2, 31-A3), lateral wall compromise |
| Bone Quality | Moderate osteoporosis | Severe osteoporosis benefits from intramedullary support |
| Patient Factors | Low-demand, stable fracture | High-demand, unstable fractureor reverse obliquity |
| Surgical Considerations | Easier technique, shorter operative time | Biomechanical superiority in unstable patterns, less varus collapse |
Surgical Mastery & Pearls
Sliding Hip Screw Technique
- Position patient supine on fracture table; achieve anatomic or slight valgus reduction.
- Confirm lateral wall integrity fluoroscopically.
- Insert guidewire centrally in the femoral neck on AP and lateral views; maintain tip-apex distance <25 mm to reduce cut-out risk.
- Ream and insert lag screw; attach side plate and secure to femoral shaft.
- Allow controlled impaction via sliding mechanism; avoid over-compression to prevent shortening.
Cephalomedullary Nail Technique
- Position patient supine; obtain fluoroscopic alignment.
- Achieve reduction with traction and rotation; confirm with AP and lateral views.
- Make a small incision at the tip of the greater trochanter; insert guidewire into femoral canal.
- Ream canal to appropriate diameter; insert nail ensuring correct depth and rotation.
- Place lag screw or helical blade centrally in femoral head with tip-apex distance <25 mm.
- Lock distal screws as indicated; consider distal locking to prevent rotation or shortening in unstable fractures.
Intraoperative Red Flags
- Varus malreduction increases failure risk; aim for slight valgus or neutral alignment.
- Excessive reaming or cortical breach predisposes to iatrogenic fractures.
- Avoid lateral wall fracture propagation during SHS insertion.
- Monitor for lag screw cut-out or nail toggle during insertion.
Evidence-Based Synthesis
Landmark randomized controlled trials and meta-analyses have clarified implant selection nuances. Early studies favored SHS for stable fractures due to simplicity and cost-effectiveness. However, recent high-quality evidence demonstrates that CMN reduces mechanical complications, especially in unstable fractures with lateral wall compromise or reverse obliquity patterns.
The HEALTH trial and subsequent meta-analyses show no significant difference in mortality or functional outcomes between implants but highlight lower reoperation rates with CMN in unstable fractures. Contradictions persist regarding operative time and blood loss, with CMN sometimes associated with longer procedures but fewer failures.
Current consensus advocates for SHS in stable, non-comminuted fractures with intact lateral walls, reserving CMN for unstable patterns. The evolving literature underscores the importance of individualized treatment based on fracture morphology and patient factors rather than a one-size-fits-all approach.
Master Class Pro-Tip
Mastery in intertrochanteric fracture fixation lies in preoperative fracture pattern recognition and intraoperative reduction precision. When using a cephalomedullary nail, prioritize achieving a tip-apex distance under 20 mm and central lag screw placement in both planes to minimize cut-out risk. In unstable fractures, proactively protect or reconstruct the lateral wall-consider adjunctive cerclage or limited open techniques-to prevent secondary collapse. This nuanced approach, combining biomechanical principles with meticulous technique, distinguishes the expert surgeon from the competent.
