femoral neck fracture overview

Femoral neck fracture management is a controversial area in orthopedics.  In attempt to simplify this situation, we are going to look at this fracture pattern in two different types of patients.  Then we’ll look at a case example that sits right in the middle of all of the important balancing acts in the management of this fracture.  First of all, this fracture pattern is a unique entity.  There are only three bones in the human body that have a recursive blood supply: meaning that the main artery that supplies blood to the anatomic area makes a U-turn as it travels past and sends a branch into the bone from a distal entry point.  Those three bones are the scaphoid in the wrist, the femoral head in the hip, and the talus in the foot.  Each of these bones has a high rate of avascular necrosis — death of the bone due to a lack of a blood supply — as the result of fractures that kink, tear, or interrupt the blood supply.

hip bones

In the following anatomic drawing — captured from Google’s body browser — we see that the blood supply to the femoral head is formed by an arterial ring created by the medial and lateral femoral circumflex arteries.  These arteries are appropriately named because they encircle the femoral head.  The most important vessel that supplies the femoral head itself is the ascending branch of the medial femoral circumflex artery and this artery is often torn by fractures of the femoral neck because these fractures separate the bone at the junction between the femoral neck and the inter-trochanteric region of the femur which is where the artery enters the bone and is most vulnerable.

blood supply to the femur  femoral neck fracture blood supply

If the blood supply to the femoral head is damaged, the head will ultimately die, the cartilage surface of the femoral head will loose its supporting network of subchondral bone, and the patient will develop arthritis due to avascular necrosis.  This is a devastating complication because it usually develops over months to years and during that time the patient is disabled, limping, and the muscles about the hip are getting weaker and weaker.  In the following series of X-rays we see the relentless progression of avascular necrosis and resulting arthritis that destroys the normal hip joint.


X-rays of progression of AVN


In general, if AVN is a foregone conclusion, then the hip joint should be replaced.  But if there is a reasonable chance that the fracture will heal and the femoral head will live, then the patient should be given the opportunity to keep their native hip.  Therefore, lets look at two distinct categories of patients.


Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>