From the Guidelines
A more curved intramedullary (IM) nail can lead to an anterior cortex fracture in the femur because it can cause malreduction of the bowed femur and increased stress on the anterior cortex 1.
Key Factors
- External rotation of the intramedullary nail during insertion can reduce the risk of malreduction of the bowed femur and accelerate fracture union 1.
- The use of intramedullary nailing is a common treatment for fractures within the femoral diaphysis, and it can provide good outcomes with complete pain relief and resumption of ambulation in a large proportion of patients 1.
- However, the curvature of the IM nail can play a crucial role in the development of anterior cortex fractures, and surgeons should be aware of this potential complication when selecting the appropriate treatment for femoral fractures.
Clinical Considerations
- Patient selection criteria are important when considering intramedullary nailing for femoral fractures, and surgeons should take into account factors such as life expectancy, mental status, mobility status, pain level, metabolic status, skin condition, and nutritional status 1.
- Preoperative assessment should include estimation of these factors to ensure that the patient is a suitable candidate for intramedullary nailing.
- Technical considerations, such as the use of locking plate technology and inflatable nails, can also impact the outcome of intramedullary nailing procedures 1.
From the Research
Factors Contributing to Anterior Cortex Fracture
- A more curved intramedullary (IM) nail can lead to an anterior cortex fracture in the femur due to a mismatch between the nail's radius of curvature and the femur's natural bow 2, 3, 4.
- The radius of curvature of the IM nail plays a significant role in determining the position of the nail tip in the distal femur, with a smaller radius of curvature resulting in a more central placement of the nail tip 2, 3.
- A posterior entry point can increase the likelihood of an anterior nail tip position, leading to a higher risk of anterior cortex fracture 5.
- The femoral angle of incidence, which is related to the femur's natural bow, can also contribute to the risk of anterior cortex fracture, with a greater angle of incidence increasing the risk 5.
Effects of Nail Radius of Curvature
- A nail with a larger radius of curvature (e.g., 200 cm) is more likely to result in an anterior nail tip position and increase the risk of anterior cortex fracture compared to a nail with a smaller radius of curvature (e.g., 150 cm) 3.
- The average femoral anterior radius of curvature is approximately 120 cm, which is less than the radius of curvature of many current IM nails, highlighting the potential for mismatch and increased risk of complications 4.
Importance of Proper Nail Selection and Placement
- Proper selection of the IM nail, taking into account the patient's femoral anatomy and the nail's radius of curvature, is crucial to minimize the risk of anterior cortex fracture 2, 3, 4.
- Accurate placement of the nail, including the entry point and starting position, is also essential to avoid complications such as anterior cortex fracture 5, 6.