Here is a common occurrence: an 88 year old woman tripped and fell on a throw rug and was seen in the emergency department. She complains of left-sided hip pain and has a bruise over the left hip and she can not get out of bed and walk. The ER physician is puzzled because the X-rays do not show an obvious hip fracture, but her clinical presentation is just like that of someone who does have a broken hip.
These x-rays were initially interpreted as being normal. Neither the ER doctor nor the radiologist saw any evidence of a fracture. However, even after 24 hours of pain control and bed rest, the patient still complained of severe hip pain. An orthopedic consultation was requested, and the consulting surgeon was suspicious that the fracture simply couldn’t be seen on the initial x-rays so a CT scan was given. The CT scan confirmed the diagnosis of a pelvic fracture. In this case, the patient’s hip held up during the fall, but there are three breaks in the pelvis. This is a very common injury pattern in which the pelvic ring is cracked by a lateral blow to the hip. Here are the relevant images from the CT scan and also an annotated x-ray of the pelvis showing where the fractures are located.
In retrospect, and with the benefit of the CT scan, it is possible to see the fractures of the superior and inferior pubic ramus on the initial x-ray of the pelvis. Pelvic fractures cause a fair amount of pain and they make it difficult to put weight on the leg, but unlike fractures of the femur, they do not need to be treated operatively in the elderly. These fractures are “STABLE” which means that the surrounding muscles, ligaments, and tendons will keep the fractures in good alignment and the fractures do not need to be fixed with screws and plates. They will heal on their own over the course of about 6-8 weeks. These patients are usually seen by physical therapy and their weight-bearing instructions are to put as much weight as is comfortable on the side that is broken. I will usually see the patient back in clinic 1-2 weeks after they are discharged from the hospital so that I can repeat an x-ray of the pelvis to make sure that nothing has moved. In my experience these fractures usually heal eventually, but the patient can be relatively disabled by hip pain for some time. Just like the treatment of fractures of the femur or the femoral neck, it is very important to pay close attention to the rehabilitation process after a pelvic fracture in order to make sure that the complications associated with bed rest and immobility do not occur.