An 80-year-old woman was trying to get out of bed when she tripped on the cord for her bedside lamp and fell onto her side. She was unable to get up after the fall and couldn't get to the phone for help. She was found a couple of hours later when her home health aide came to check on her.
She denies numbness, tingling, chest pain, fevers, chills, abdominal pain, and shortness of breath, but she is unable to put any weight on her leg.
She has a history of hypertension and atrial fibrillation, but she isn't on Coumadin. What does this photo tell you about the diagnosis? How would you evaluate and manage this condition?
Find the diagnosis and case discussion on p. 20.
Diagnosis: Posterior Hip Dislocation
Traumatic hip dislocations are not extremely common, but they are an orthopedic emergency and need to be dealt with in a timely manner to avoid complications and patient morbidity. One of the main complications of osteonecrosis is significantly increased the longer it takes for the reduction. Posterior hip dislocations are the most common dislocation (90%) while anterior dislocations represent fewer traumatic dislocations — 10 percent. (J Trauma 2003;55:135.) Posterior hip dislocations often result from high-energy injuries such as car crashes. Remember, however, these dislocations can happen in the elderly with something as minor as a fall from standing.
The usual presentation is of a shortened and internally rotated leg. This is different from an anterior dislocation, which will not be as noticeably shortened and will instead be externally rotated, extended, and abducted. (Clin Orthop Relat Res 2000;377:15.) It is also important to have a high level of suspicion for an associated fracture in these cases, which might complicate how patients present.
Anteriorposterior (AP) x-rays of the pelvis should show the dislocation, but patients might also need a lateral x-ray. Posterior and anterior hip dislocations present with subtle signs. X-rays of posterior hip dislocations show a smaller and more superiorly located femoral head while the lesser trochanter seems to disappear. Anterior dislocations might make the femoral head appear larger and the lesser trochanter more prominent. Sometimes a CT scan of the pelvis will be needed to help with the diagnosis and the type of dislocation present if it is not clear on the x-rays. The CT may even reveal small fractures not seen before. (J Am Acad Orthop Surg 1997;5:27; Clin Orthop Relat Res 2000;377:15.)
It is also extremely important to do a thorough neurovascular exam with these injuries because nerve injuries can occur. The sciatic nerve is the most common nerve injury. (Clin Ortho Relat Res 2000;377:84.) Be sure to look for other areas that might be injured because hip dislocations often require a lot of force. Studies have shown that patients will often also have associated knee injuries, for example. (Clin Orthop Relat Res 2000;377:78; J Bone Joint Surg Am 2005;87:1200.)
Current recommendations call for reducing the hip within six hours to prevent avascular necrosis of the femoral head. (J Bone Joint Surg Br 1991;73:465.) The two most common methods to reduce hip dislocations are the Stimson and Allis maneuvers. With the Allis maneuver, someone helps hold the pelvis while another person applies traction in the same line as the dislocation. During traction, internal and external rotation is also applied to the hip. The person pulling traction will often need to get on the patient bed to get enough leverage. (Clin Orthop Relat Res 2000;377:24.) The Stimson technique uses gravity by placing the patient prone with the extremity hanging off the end of the stretcher. The hip is then flexed at 90 degrees, and downward pressure is put on the knee. This maneuver is not used as often because, as you can imagine, it's difficult to move a patient with many injuries into a prone position. (Clin Orthop Relat Res 2000;377:24.)
The patient was immediately brought to a resuscitation room where she received conscious sedation and reduction of her hip using the Allis maneuver. She followed up with orthopedic surgery, and eventually needed a hip replacement after two more falls and dislocations. She is currently doing well.
This issue marks the first column by a new author for Quick Consult, Bonnie Kaplan, MD, an assistant professor of emergency medicine at the University of Colorado School of Medicine in Aurora. She came highly recommended by the column's previous author, Jennifer Wiler, MD, MBA, who has so much on her plate these days it's tough to imagine that she found the time to write for EMN for nine years! (Did we mention she's also a mother of three?)
Dr. Wiler wasn't Quick Consult's first author, but she definitely turned it into one of our most popular features. She'll remain on our editorial board so her influence will continue, but we'll miss her unique take on diagnosing tough cases with limited information. But, as she noted, she leaves us in capable hands, and as you'll see in the months to come, Dr. Kaplan has recruited a contingency of new voices to continue the Quick Consult tradition.
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