KEY POINTS
- Fractures can be to the ankle, lower leg or thigh.
- Splinting can provide considerable pain relief and reduce bleeding.
- Cover open fractures with a damp dressing.
EXPLANATION
A hard landing on the legs can lead to a broken ankle, lower leg (tibia and fibula) or a broken thigh (femur). Ankle injuries commonly occur from trips on launch or a landing on uneven ground. It can be difficult to tell the difference between a severely sprained ankle and a fracture, so an x-ray is advisable in almost all cases. A femur requires a great deal more force to break, so a fracture should raise your suspicion of other serious injuries.
Broken limbs are best treated in the field by splinting. Splinting a limb means immobilising the joints or joints above and below the injury to prevent any movement of the fracture site. Some commercial splints also apply traction, a gentle but consistent pulling force on the limb that helps realign the normal anatomy. While traction is helpful in femur fractures, it is the ‘icing on the cake’. The most important thing is to achieve proper immobilisation, providing pain relief and preventing worsening of the injury.
Tips for splinting:
When shaping an improvised splint, use the other arm to mould it before applying to the injured side.
Make sure to pad any points of the splint that will apply pressure to the skin. Pressure sores develop quickly and can take a long time to heal.
Use the other leg as a support for the injured side and always tie the ankles together.
‘SAM’-style splints – flexible, lightweight, foam and aluminium splints are fantastic and can be stashed under the seat or down the back of a harness.
Before and after splinting, check that the blood and nerve supply to the limb are still intact beyond the fracture site. Signs that the blood or nerve supply might not be okay include a cold, pale, pulseless or painful limb, absent or altered sensation (e.g. pins and needles). The limb may need to be repositioned back into ‘normal’ alignment if any of these occur.
Assessing a Suspected Lower Limb Fracture
If you suspect a lower limb fracture, start by asking the casualty to describe what happened and where it hurts. Look for obvious deformity, swelling, bruising or an unnatural angle of the leg. Do not deliberately try to move the limb to test for pain; if the leg is already in a position that causes severe discomfort, leave it there until you are ready to splint. Gently feel along the length of the bone only if necessary to locate a tender spot, but avoid pressing directly over a suspected fracture site.
After checking for visible signs, assess the circulation and nerve function below the injury. Compare the injured side with the uninjured side. Feel for pulses in the foot — the dorsalis pedis pulse on the top of the foot and the posterior tibial pulse behind the inner ankle. Check capillary refill by pressing on a toenail until it blanches and timing how quickly the colour returns; normal is under two seconds. Ask the casualty to wiggle the toes and to tell you if they can feel light touch on the foot. Note any numbness, tingling, coldness or pale or blue discolouration, as these suggest reduced blood flow or nerve compression and must be treated as urgent.
Record your findings and repeat the checks every 15 to 30 minutes while awaiting evacuation. A change from normal pulse or sensation to abnormal is an important warning sign, even if the limb looked fine at first.
Pain Management and Positioning
Pain from a lower limb fracture can be severe, and reducing it helps prevent the casualty from moving the leg involuntarily. Simple oral analgesics such as paracetamol or ibuprofen are safe for most adults and can be given while you prepare to splint. If stronger prescription pain relief is available and you are trained to use it, follow your local protocols. Avoid giving aspirin if there is significant bleeding or if the casualty may need surgery soon, as it can increase bleeding.
Position the casualty so that the injured leg is supported along its whole length. A pillow, rolled blanket or padded rucksack placed under the calf and ankle can help maintain a comfortable, slightly bent knee position if that reduces pain, but do not force the limb into a position that worsens discomfort. If the leg is straight and the casualty finds it tolerable, keep it straight, particularly when preparing to apply a traction splint. Elevating the leg above heart level may reduce swelling after immobilisation, but only do this if it does not cause additional pain.
Cold therapy can provide useful pain relief and limit swelling. Wrap an ice pack, frozen gel pack or a bag of cold water in a cloth and place it over the injured area for up to 20 minutes at a time. Never apply ice directly to the skin, and avoid cold therapy if the foot is already cold or numb, as this may worsen poor circulation.
Open Fractures and Wound Management
An open fracture occurs when the broken bone tears through the skin, creating a wound that communicates with the fracture site. This dramatically increases the risk of infection and requires careful wound care in addition to splinting. If you see bone protruding or a deep wound over a suspected fracture, do not attempt to push the bone back under the skin. Leave any visible bone fragments exactly as you find them and handle the limb as gently as possible.
Control bleeding by applying direct pressure with a clean cloth or sterile dressing around the wound edges, not directly on the protruding bone. Once bleeding is controlled, cover the wound and any exposed bone with a dressing moistened with sterile saline or clean water. The moist covering prevents the bone and surrounding tissues from drying out, which reduces further damage. If sterile saline is not available, use the cleanest water you have, ideally boiled and cooled, and then cover the moist dressing with a dry sterile bandage to keep it in place.
Do not probe the wound, attempt to remove debris or apply antiseptics directly into the open fracture site. These actions can introduce bacteria deeper into the tissues. If antibiotics are available and you are authorised to administer them, follow your local protocol, but general first aid in the field focuses on wound coverage, splinting and rapid evacuation. Check the casualty’s tetanus immunisation status if possible and include this information when handing over to medical personnel.
Complications to Watch For
Even after a lower limb fracture has been splinted and the casualty is comfortable, serious complications can develop hours later. The most important to recognise early is compartment syndrome, a build-up of pressure inside the muscle compartments of the leg that can cut off blood supply and lead to permanent muscle and nerve damage. The classic signs are pain that is out of proportion to the injury, pain that worsens when the toes are passively stretched, a tense or hard swelling in the calf or thigh, and later numbness or weakness. Pulselessness is a very late sign; do not wait for the foot to lose its pulse before suspecting compartment syndrome.
Another life-threatening complication is shock from blood loss, particularly with a fractured femur, which can hide a litre or more of blood in the thigh. Watch for pale, cool and clammy skin, a rapid weak pulse, dizziness, confusion or collapse. Keep the casualty lying flat, keep them warm, and do not give anything to eat or drink in case surgery is needed. If you are in a remote setting, monitor the casualty continuously and be prepared to treat for shock while arranging evacuation.
Finally, check the splinted limb regularly for signs that the splint itself is causing problems. Ensure that bandages are not too tight by checking that the toes remain pink, warm and mobile. If swelling increases, loosen the outer bandages slightly but do not remove the splint. Document any change in pain, sensation, colour or temperature and pass this information to the rescue team.