What are the advantages of treating a mid-shaft femoral shaft fracture with an intramedullary nail as compared to casting or traction?

(Also: what complications/patient morbidity may be seen despite this treatment?)

 

 

A mid-shaft femoral fracture in a skeletally mature individual is most commonly treated with an intramedullary (IM) nail (Figure 1). Other treatment options include casting and traction. Unless the patient is not stable enough for surgery, IM nail is the preferred treatment for two major reasons: a nail preserves bone alignment and maximizes patient mobility.

 

The goal of treatment in fracture is restoration of function, and for a femur fracture, that means (at the minimum) the limb’s original length and alignment must be restored.

 

By using an IM nail, the bone is fixed at its intended length, alignment and rotation. Without a nail, the pull of muscles still attached might tend to shorten, bend, or rotate the bone (Figure 2).

 

Additionally, the IM nail usually provides enough strength and stability such that patients can bear at least some weight soon after surgery, and even if weight bearing were not allowed, the nail is a big improvement over a cast, as it frees the knee and the hip to move without restriction. (Immobilizing the joint above and below is mandatory when casting.) This freedom reduces the likelihood of muscle atrophy and joint stiffness.

 

Figure 1: Left, Midshaft fracture of the femur (Image courtesy of Radiopedia.org rID: 22120); Right, Femur fixation with IM nail (Image courtesy of orthopaedicsone.com)
 
Figure 2: Without a nail, the fracture depicted in Figure 1 and again on the left of this image might heal in a short and bent position because of the pull of the adductor muscles, as shown here. (Image modified from Wikipedia.org)

 

When a patient is in traction, he or she must remain in bed. Not only can this result in atrophy and stiffness, but it is also associated with complications such as bed sores, blood clots, and atelectasis.

 

While IM fixation provides better outcomes in patients with mid-shaft femoral fractures, it does not eliminate all potential complications and might heighten the risk of some. In particular, inserting a nail, especially if the intramedullary space is reamed to make more room for the device, can push bone marrow into the systemic circulation.

 

Although the entry of marrow contents into the systemic circulation can be a result of the fracture itself, the surgery may amplify this process. Fat globules from the bone marrow can potentially lodge in the lungs, causing adult respiratory distress syndrome (ARDS), or they may land in the brain, causing a stroke or ischemic injury.

 

Bone marrow contents are also known to be thrombogenic. The resulting clot forming in a leg vein can embolize to the lung and possibly kill the patient.

 

In sum, IM nail is a preferred method of treatment for mid-shaft femoral fractures because it allows for restoration of the normal skeletal anatomy and promotes mobility. Nailing is, however, not without risks and does not free the patient from all potential complications associated with this high-energy injury.