intertrochanteric femur fractures CASE 37

A 34-year-old, male bull rider is brought to the emergency department after being bucked from his bull. He has abrasions over his left upper and lower extremities with exquisite tenderness over his left hip, pain with longroll, and tenderness in his left groin. An AP pelvis radiograph is shown in Figure 6–38.

 

 

 

Figure 6–38

 

What treatment is most appropriate in this injury?

1. Lateral entry long intramedullary nail

2. Piriformis entry long intramedullary nail

3. Sliding hip screw

4. Short cephalomedullary nail

5. Long cephalomedullary nail

 

Discussion

The correct answer is (E). When choosing an implant for fixation of an intertrochanteric femur fracture, it is most important to consider the fracture stability. The above fracture is a comminuted, reverse oblique fracture. Due to the reverse oblique nature of the fracture, a sliding hip screw, short intramedullary nail, and standard femoral intramedullary nail are not appropriate implant choices when considering the risk of excessive collapse with use of these implants.

When using an intramedullary nail for fixation of the above fracture, what factor can cause peri-implant failure at the time of placement?

1. Lateral starting point

2. Varus malreduction

3. Use of smaller diameter interlocking screws

4. Tip-apex distance equal to 16 mm

5. Nail radius of curvature equal to 300 degrees

Discussion

The correct answer is (E). Larger nail radius of curvature is associated with higher rate of anterior cortex penetration at the time of implant placement. The average femoral anatomic radius of curvature is approximately 120 degrees. As such, femoral intramedullary implants with larger radii of curvatures (more straight) place increased stresses on the anterior cortex. This can cause an increased risk of anterior distal femoral cortex penetration. A tip-apex distance greater than 25 mm is associated with increased implant cutout. Varus malreduction and a lateral starting point have not been shown to have higher rates of peri-implant failures. Of note, peri-implant fractures are more common when using nails compared to plates.

What is predictive of mortality in patients greater than 65 following a hip fracture at 2 years post-injury?

1. Mechanism of injury

2. American Society of Anesthesiologist (ASA) classification

3. Length of surgery

4. Male sex

5. Type of fracture

 

Discussion

The correct answer is (B). Hip fractures in elderly patients are associated with higher rates of mortality at 6 months. However, in patients greater than 65, increased ASA classification at the time of surgery has been shown to have a mortality rate three times that of those with lower ASA scores. Other categories have not been shown to have higher rates of mortality at 2 years. Other predictors of mortality in the first year following a hip fracture include: male gender, intertrochanteric fracture, fixation delay greater than 4 days, age greater than 85, higher ASA classification, and increased number of medical conditions.

 

Objectives: Did you learn...?

 

 

Fixation options for intertrochanteric femur fractures? Importance of implant design on fracture fixation?

 

Predictors of mortality following hip fractures?