Posted by Andy Jagoda, MD in: Brain Tease , trackback
Dislocation of the major joints of the lower extremities–hip, knee, and ankle–can occur due to motor-vehicle crashes, falls, and sports injuries. These are painful presentations in the trauma ED that must be managed quickly to avoid morbidity, disability, and even possible amputation.
Test Your Knowledge
Did you get it right? Click here to find out!
The correct answer: B.
Need a refresher on the subject? Review the summary below:
Points from Managing Dislocations of the Hip, Knee, and Ankle in the Emergency Department (Trauma CME):
- 90% of hip dislocations are posterior; 10% percent are anterior.
- Typically, an AP pelvic radiograph is adequate to diagnose a hip dislocation. Judet views are help?ful in diagnosing associated fractures.
- Traumatic dislocations of the native hip should be reduced within 6 hours to reduce the risk of avascular necrosis and posttraumatic arthritis.
- The Allis, Bigelow, Captain Morgan, Rocket Launcher, and East Baltimore Lift techniques can all be used to reduce a hip dislocation. None have proven to be superior to the others; the choice can be made according to provider capability and preference.
- All hip reduction methods can be used on both native and prosthetic hips.
- Consider an ultrasound-guided fascia iliaca com?partment block to augment and reduce proce?dural sedation and analgesia.
- All hip fracture dislocations should be deferred to orthopedic surgery.
- After reduction of a native hip dislocations, a CT scan should be obtained. The patient will need to be admitted to the hospital.
- Many knee dislocations spontaneously reduce. Maintain a low threshold of suspicion for this injury, as missing a knee dislocation could have catastrophic consequences.
- In any knee dislocation with a pulse deficit, perform immediate reduction without imaging. Delays longer than 8 hours have a higher inci?dence of amputation.
- After reduction of the dislocated knee, patients should be admitted for serial vascular examina?tions or vascular imaging should be obtained. Compartment syndrome is a delayed complica?tion of knee dislocations.
- Ankle dislocations require immediate recognition and prompt reduction, as they can be associated with significant neurovascular, skin, and soft-tissue complications.
- Subtalar dislocations are rare, but appear similar to ankle dislocations. Attempting to reduce a subtalar dislocation before imaging may lead to worsening of the dislocation.
- Emergent orthopedic consultation and post-reduction CT are necessary after reduction of a dislocated ankle.