|
Year |
2002 |
|---|---|
|
Question Number |
195 |
|
Category |
Musculoskeletal Trauma |
Question
A 25 year old sustains a closed midshaft femur fracture in a motorcycle accident. After insertion of an antegrade, statically locked femoral nail, intraoperative radiographs reveal an ipsilateral, nondisplaced femoral neck fracture. What is the most appropriate management?
1- Nonsurgical management of the femoral neck fracture
2- Stabilization of the femoral neck fracture with lag screws anterior to the existing femoral nail
3- Removal of the nail and replacement with a long intramedullary hip screw
4- Removal of the nail and replacement with a reconstruction nail
5- Removal of the nail, stabilization of the femoral neck with lag screws, and retrograde nailing of the femoral shaft fracture
Figures
Answer (click for answer)
Preferred Answer 2
Concurrent ipsilateral femoral neck fractures are reported in 2.5% to 5% of patients with femoral shaft fractures. Whereas the shaft fractures vary widely in their location and comminution, the neck fractures usually are a vertical shear (Pauwels grade III) pattern. The typical neck fracture commences inferiorly at the base of the femoral neck and travels superiorly to the subcapital portion of the neck. Because much of the impact energy of the injury is dissipated at the shaft fracture, the neck fracture usually is minimally displaced and noncomminuted. Therefore, the prevalence of osteonecrosis of the femoral head is low after this combined femoral fracture. Diagnosis of the neck fracture often is delayed because of failure to evaluate the entire femur radiographically when there is a shaft fracture. About one fourth to one third of neck fractures initially are overlooked, and then subsequently are detected after stabilization of the shaft fracture.
Delayed diagnosis is not associated with an increased rate of femoral head osteonecrosis and most cases can be salvaged with good functional results by closed reduction and insertion of multiple pins or screws around in situ nails. The literature describes some of the femoral neck fractures as iatrogenic injuries created at the time of intramedullary nailing. It is difficult to separate this group from those that are present before surgery but are recognized only after the procedure. Although an incorrect starting position of the intramedullary nail may increase the likelihood of an iatrogenic neck fracture, it is probable that many of these injuries are not recognized before surgery and then are attributed to, or propagated by, the surgical procedure. Femoral neck nonunion and malunion are more common problems than are osteonecrosis of the femoral head or complications secondary to the shaft fracture. Therefore, it is important to give priority to anatomical reduction and rigid internal fixation of the femoral neck fracture. Subcapital and transcervical fractures usually are stabilized with lag screws; fractures occurring at the base of the neck or the intertrochanteric region can be treated best with sliding compression screw devices.
Removal of the femoral nail and retrograde methods must be used cautiously because they impart a cephalad load in the proximal femur that can lead to varus displacement of a femoral neck fracture.
Reference: Kellam JF, Fischer TJ, Tornetta P III, Bosse MJ, Harris MB (eds): Orthopaedcis Knowledge Update: Trauma 2. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000,pp 133-146