Hip-Reduction Problem
A 79-year-old man with left hip pain presented to the ED via EMS. The patient stated that when he had bent over to retrieve his dropped glasses, he experienced the immediate onset of left hip pain and fell to the floor. He was unable to get up on his own and called EMS. The patient had undergone total left hip replacement 1 month prior. At presentation, he complained only of severe pain in his left hip; he denied head injury, neck pain or stiffness, chest pain, or abdominal pain. His past medical history was significant for hypertension and type 2 diabetes mellitus. The patient had no known drug allergies.
On physical examination, he was mildly tachycardic. His vital signs were: heart rate, 102 beats/minute; blood pressure, 156/88 mm Hg; respiratory rate, 20 breaths/minutes; and temperature, afebrile. His pulse oximetry was 98% on room air. The HEENT, lung, heart, and abdominal examinations were all normal. Standing at the foot of the bed, the patient had obvious shortening, internal rotation, and adduction of the left leg. The left knee was without tenderness or swelling. The neurovascular examination of the left lower extremity was completely normal.
Plain radiographs of the pelvis and left hip ordered by the EP demonstrated a posterior hip dislocation with intact hardware. The EP consulted the patient’s orthopedic physician, and both agreed the EP should attempt to reduce the dislocation in the ED. Using conscious sedation, the EP was able to reduce the dislocation, but postreduction films demonstrated a new fracture requiring orthopedic surgery. Unfortunately, the patient had a very difficult recovery, ultimately resulting in death.
The patient’s estate sued the EP, stating he should have had the orthopedic physician reduce the dislocation. The defense argued that fracture is a known complication of reduction of a dislocated hip. A defense verdict was returned.
Discussion
Approximately 85% to 90% of hip dislocations are posterior; the remaining 10% are anterior. Posterior hip dislocations are a common complication following total hip-replacement surgery.1 Hip dislocation is a true orthopedic and time-dependent emergency. The longer the hip remains dislocated, the more likely complications are to occur, including osteonecrosis of the femoral head, arthritic degeneration of the hip joint, and long-term neurological sequelae.2 The treatment of posterior hip dislocation (without fracture) is closed reduction as quickly as possible, and preferably within 6 hours.3 As this case demonstrates, minimal forces can result in a hip dislocation following a total hip replacement. In healthy patients, however, significant forces (eg, high-speed motor vehicle crashes) are required to cause posterior hip dislocation.
Patients with a posterior hip dislocation will present in severe pain and an inability to ambulate. In most cases of posterior hip dislocation, the affected lower extremity will be visibly shortened, internally rotated, and adducted. The knee should always be examined for injury, as well as performance of a thorough neurovascular examination of the affected extremity.
Plain X-ray films will usually identify a posterior hip dislocation. On an anteroposterior pelvis X-ray, the femoral head will be seen outside and just superior to the acetabulum. Special attention should be made to the acetabulum to ensure a concomitant acetabular fracture is not missed.
Indications for closed reduction of a posterior hip dislocation include dislocation with or without neurological deficit and no associated fracture, or dislocation with an associated fracture if no neurological deficits are present.2 An open traumatic hip dislocation should only be reduced in the operating room.
It is certainly within the purview of the EP to attempt a closed reduction for a posterior hip dislocation if no contraindications exist. The patient will need to be sedated (ie, procedural sedation, conscious sedation, or moderate sedation) for any chance of success at reduction. While it is beyond the scope of this article to review the various techniques used to reduce a posterior hip dislocation, one of the guiding principles is that after two or three unsuccessful attempts by the EP to reduce the dislocation, no further attempts should be made and orthopedic surgery services should be consulted. This is because the risk of complications increases as the number of failed attempts increase.
It is unclear how many attempts the EP made in this case. Fracture is a known complication when attempting reduction for a hip dislocation, be it an orthopedic surgeon or an EP. It was certainly appropriate for the EP in this case to attempt closed reduction, given the importance of timely reduction.