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Pelvis and femur fracture

Pelvis and femur fracture – August 2015

Of the traumatic musculoskeletal injuries, fracture of the pelvis or the femur have to have a case for being the most significant. Aside from when the bones themselves are diseased, both are strong and require a lot of force to break. When broken, both are major injuries. When they occur together, the patient is both very sick and challenging to manage.

Start with the pelvis. This ringed bone houses the bladder, part of the uterus in women, bit of colon, urethra and a number of major blood vessels. When the ring of the pelvis is broken from trauma, there are two standout features. The first is that some of these highly vascular structures normally protected within the ring can be injured. Major bleeding can be the result. A fractured pelvis is the one fracture that can cause truly life threatening bleeding to occur.

The second standout feature is that once the ring is broken, the space the ring encloses increases. This means that any bleeding that does occur within the ring will have a bigger volume to bleed into allowing more blood to be lost.

When assessing for a fractured pelvis, normal signs of fracture are looked for. In particular though, it is important to assess the pelvis for normal shape and symmetry. With the pelvis exposed, stand in front and behind it to see if it looks uniform. Do the legs appear to sit evenly and of the same length? If the ring remains intact, the fracture is less significant than where deformity is noted. Just as with other fractures, it is important to not move the pelvis around during assessment. Compressing the pelvis during assessment was once normally performed in what is called ‘springing’. This is very unreliable to interpret and can worsen injury and aggravate pain.

Where the pelvic ring has been distorted and lost its normal shape, it is called an open book fracture. This is the worst outcome. Management is relatively simple in theory. Effective analgesia is likely needed. Then the ring needs to be closed as best as practicable. This is done by bringing both legs together to close the symphysis pubis. A compression splint is then applied right around the pelvis to squeeze the pelvis back into shape.

This is an important point. If the pelvis is in its normal shape already and the ring is not broken, a pelvic splint is not really necessary. The ring cannot be compressed smaller than its normal shape. When in doubt, treat as for the worst case scenario.

There are several options for pelvic splint. A purpose splint such as the SAM sling splint is one option. Their advantage is that it is easy to apply and can provide the right amount of required force. The disadvantage is that they are relatively easy to apply incorrectly. The common error is to apply them either too high or too low. The level of force needs to be over the greater trochanters. In practice this seems too low for some. A refresher look at a skeleton should be a good reminder that it is just right though. The much higher iliac crests can be deceptive but they are not key to pelvic ring structure.

Alternatively a sheet wrap can be used instead. Depending on the method used, a good amount of compression force can be applied. Further, because this method covers more of the body and leg than a SAM splint, it is more likely to be sure it provides the force over the trochanters. In fact, the sheet wrap will apply the most force at this point as this is the widest point of the hips.

One difficulty with managing the fractured pelvis is where there is also injury to the femur. Femur fractures are not quite so bad in practice. They too are very painful. They also usually take a fair force to break them. Where the fracture is around the middle of the femur, or the tibia for that matter, a traction splint can be applied. These long bones have a large muscle mass attached that has major blood vessels nearby. The large muscles can spasm without the normal skeleton and tendons in place to stop them. This is not only painful, it can worsen injury present. Traction splinting is usual to hold the bone in relatively normal placement and stop this happening. Though bleeding is common it is usually contained within the thigh itself. Blood loss from one femur fracture is typically considered at most around one litre.

An extra complication is an open femur fracture that has been soiled during the trauma. This might be dirt, gravel or any other contaminant. Though contentious, applying traction is still important. The wound should be rinsed as best as possible before the traction is applied but the wound will need debriding and cleaning regardless. Infection risk is high so the wound should also be lightly covered as well unless bleeding requires direct pressure placed on it.

If knee or ankle joints are involved, traction should not be applied. In such cases further injury occur as well as the increase in pain. Lower tibia fractures also do not need traction splinting as there is no large muscle mass nearby to spasm, only tendon. Similarly, where the femur fracture does not appear to have completely parted the bone and the leg still looks relatively normal, traction does not need to be applied. If the bone is already its normal length there is no advantage in pulling on it. This is the same principle as when managing a pelvic fracture with intact ring.

The question then is, what if there is a pelvic and femur fracture together? Firstly, the pelvic fracture is the one that can be life threatening. If one injury must be given priority, it must be the pelvis. But it is more likely that both can be managed together.

The first rule to know is that traction correctly applied to a femur fracture will not pull or push on or interfere with the pelvic fracture above it. The worst that might be possible is that the ischial ring might press into the injured part. This ischial ring can also cause the legs and hence the symphysis pubis to be kept slightly apart. This is not desirable but tolerable if the benefit of traction is needed.

If a traction splint is applied, it may be easier to fit it first, then apply the pelvic splint over the top of it. This will work better with a SAM splint. The pelvic sheet wrap that covers a larger area may compress the traction splint as well making it difficult to use both at once. It is also critical to remember that when applying the traction splint first, the lesser injury is being managed first. This is reverse to normal thinking and only being done this time for practical reasons. As such both splints should be fitted in quick time making regular practice in their use vitally important.

Finally, once applied, neither should be taken off again before hospital. Increased pain and bleeding and worsening of injury can result so removal of such splints must be slowly done and carefully supervised.

Jeff Kenneally –