Frequency of Subtrochanteric Femoral Fractures After SIGN Locking Intramedullary Nails
The available evidence does not provide specific data on the frequency of subtrochanteric femoral fractures following SIGN (Surgical Implant Generation Network) locking intramedullary nail placement, as no studies in the provided literature directly address this question.
What the Evidence Actually Shows
Iatrogenic Subtrochanteric Fractures During Nail Insertion
The literature addresses intraoperative subtrochanteric fractures that occur during trochanteric nail insertion for femoral shaft fractures, not post-operative fractures after healing:
- Intraoperative fractures can occur during trochanteric intramedullary nailing when treating femoral shaft fractures, particularly with nails that have a proximal lateral bend designed for trochanteric insertion 1
- These complications are related to technical insertion issues rather than post-operative fracture occurrence 1
Prevention Strategies for Intraoperative Complications
To minimize iatrogenic fractures during nail placement:
- Thorough preoperative assessment of the entire femur is essential to identify any proximal lesions that could lead to implant failure 2
- Adequate preoperative imaging prevents missed pathology and suboptimal implant selection 2
- External rotation of the intramedullary nail during insertion can reduce the risk of malreduction in bowed femurs 3
Context: Atypical Femur Fractures (Different Population)
The evidence does discuss subtrochanteric fracture frequency, but in an entirely different clinical context—bisphosphonate-associated atypical femur fractures:
- Atypical femur fracture incidence is 55 per 100,000 person-years in bisphosphonate users versus 1 per 100,000 in bisphosphonate-naive patients 3
- This data is not applicable to post-intramedullary nailing patients, as it relates to medication-induced bone changes, not surgical hardware complications 3
Critical Knowledge Gap
No evidence in the provided literature specifically quantifies the rate of new subtrochanteric fractures occurring after successful SIGN nail placement and fracture healing. The studies focus on union rates, reduction quality, and intraoperative complications rather than subsequent fracture risk 4, 5, 6, 7.