Although posterior hip dislocation is an uncommon injury, the consequences of delayed recognition or treatment can be dire. The majority are caused by head-on car crashes, and 90% of these are posterior dislocations. The femoral head is forced across the back wall of the acetabulum, either by the knee striking the dash, or by forces moving up the leg when the knee is locked. This occurs most commonly on the right side when the driver is standing on the brake pedal, desperately trying to stop.
On exam, the patient presents with the hip flexed, internally rotated and somewhat adducted. Range of motion is limited, and increasing resistance is felt when you try to move it out of position. An AP pelvic X-ray will show the femoral head out of the socket, but it may take a lateral or Judet view to tell if it is posterior vs anterior.
These injuries need to be reduced as soon as possible to decrease the chance of avascular necrosis of the femoral head. Procedural sedation is required for all reductions, since it makes the patient much more comfortable and reduces muscle tone. The ED cart needs to be able to handle both the patient’s weight and your own. I also recommend a spotter on each side of the cart.
Standing on the cart near the patient’s feet, begin to apply traction to the femur and slowly flex the hip to about 90 degrees. Then gently adduct the thigh to help jump the femoral head over the acetabular rim. You will feel a satisfying clunk as the head drops into place. Straighten the leg and keep it adducted. If you are unsuccessful after two tries, there is probably a bony fragment keeping the head out of the socket
Regardless of success, consult your orthopedic surgeon for further instructions. And be sure to thoroughly evaluate the rest of the patient. It takes a lot of energy to cause this injury, and it is flowing through the rest of the patient, breaking other things as well.
This month is the 20th anniversary of the MESS score, a system that helps predict salvageability of mangled extremities (Mangled Extremity Scoring System). Obviously, the acronym was chosen to help describe the clinical problem.
The system was originated at the Harborview Medical Center in Seattle. The development was not very scientific; the authors put their heads together and made a list of the four things that they observed predicted limb salvage:
- Degree of skeletal and soft tissue injury
- Presence of limb ischemia
- Presence of shock
The system was used retrospectively in a group of 25 patients(!) and the authors found a nice breakpoint at 7. Any mangled extremities with a MESS of 7 or more required amputation. They then applied this to 26 patients prospectively(!) and got the same result.
As you can see, the numbers were small, and there was no followup information. Nevertheless, MESS still stands today, and the critical MESS score has not changed much. It has been validated by a number of other studies during the past 20 years. It is conceivable that the critical score will slowly creep upward with advancements in flap coverage and surgical technique, but it hasn’t done so yet.
Reference: Objective Criteria Accurately Predict Amputation Following Lower Extremity Trauma. Johansen, et al. J Trauma 30(5): 568, 1990.
Nurses have a complementary role with physicians in caring for children with orthopedic injuries. Typically, the child will have been evaluated and had some sort of fracture management implemented. In children, nursing management is easer than in adults since a child is less likely to need an invasive surgical procedure. Many fractures can be dealt with using casts and splints alone.
Here are a few tips for providing the best care for you pediatric patients:
- Ensure adequate splinting / casting. You will have an opportunity to see the child at their usual level of activity. If it appears likely that their activity may defeat the purpose of the cast or splint, inform the surgeon or extender so they can apply a better one.
- Focus on pain control. Nothing aggravates parents more than seeing their child in pain! Make sure acetominophen or ibuprofen is available prn if pain is very mild, or scheduled if more significant. Ensure that mild narcotics are available if pain levels are higher. Remember, stool softeners are mandatory if narcotics are given.
- Monitor compartments frequently. If a cast is used, check the distal part of the extremity for pain, unwillingness to move, numbness or swelling. If any are present, call the physician or extender and expect prompt attention to the problem.
- Always think about the possibility of abuse. Fractures are rarely seen in children under 3, and almost never if less than 1 year old. If you have concerns about the physical findings or parent interactions, let the physician and social workers know immediately.