Complications

What other problems occur from a fracture?

Following treatment of a fracture we expect the wounds to heal up and the bone to heal in good position without delay; we also expect the limb to continue without any adverse events. The probability that this will happen is high but not 100%. When adverse events occur following a fracture healing is said to be “complicated”.

Infection

After an open fracture the tissues are contaminated and there is a risk of bacterial infection. More rarely, bone infection may follow surgery to fix a fracture. These are serious problems which may delay or halt bone healing or cause a long-term infection in the bone even if it does heal. Bone infection is treated vigorously with antibiotics and with surgery to wash out and cut out any infected or dead tissue.

Compartment Syndrome

Some of the limb muscles are enclosed in a sheet of fibrous tissue forming a muscle compartment that does not stretch. If the muscle swells as a result of injury the pressure inside the muscle compartment can rise to dangerous levels and cut off circulation to the muscle. The hallmark of this problem is relentlessly rising levels of pain, made worse by any attempt to contract or stretch the muscle or to push on the compartment. Major long-term damage can occur if this situation is not identified and treated by surgery to relieve the pressure (fasciotomy). This complication is particularly common after an injury to the blood supply of the limb.

Venous Thrombo-Embolism (VTE)

Part of the natural response to injury is to increase the likelihood that the blood will clot. This has obvious value in limiting blood loss. However, in the period immediately following a fracture the circulation may be slower or stagnant due to swelling. There is a risk that the blood will clot in the veins (thrombosis) causing further problems with the circulation and increasing the swelling of the limb. In addition there is a risk that a portion of the blood clot will break off and float up the veins to lodge in the lungs. This dangerous process is called ‘embolism’. The complete scenario is called Venous Thrombo-Embolism or VTE.

Treatment to reduce the risk of VTE may include early mobilization and the encouragement of foot and ankle movement to aid circulation in the legs. Compression stockings may also be used and in some high risk situations, blood thinning medication. Doctors and nurses are very much on the look-out for signs of VTE.

Fat Embolism Syndrome (FES)

This rare but serious condition can occur after about one in fifty major long bone fractures. Fat globules from the bone marrow enter the blood circulation via damaged vessels and pass to the lungs and brain. Under certain conditions this sets up an inflammatory response compromising lung function and clouding consciousness. Often the first sign is confusion, followed by respiratory problems.

The condition itself is short lived and self limiting but the patient may need intensive care, including ventilator support, in the short term. Formerly, this rare condition was fatal in 10 percent of FES cases; with early recognition and aggressive supporting treatment this figure is now much less. However, it does remain one of the few complications of otherwise straightforward fractures that can provoke an emergency.

Neurovascular Impairment

The nerves, arteries and veins which pass down a limb may be injured when a bone is broken. Their function may also be impaired by the swelling that follows a fracture or by surgery to treat the fracture. So for a number of reasons the nerve supply or the blood supply of the limb may be inadequate after a fracture.

Regional Pain Syndrome

Occasionally a fracture triggers an abnormal pain reaction which continues long after the injury has healed. It is characterized by burning pain, swelling and stiffness of the limb.

Related Document: A Patient's Guide to Pain Management: Complex Regional Pain Syndrome

Nonunion

The process of healing can be delayed (delayed union) or fail altogether (nonunion). If there is no x-ray signs of healing after three months it is considered delayed union; if the fracture is still mobile and painful after six months it would be treated as a nonunion.

There are specific x-ray findings that more strongly suggest a nonunion or ‘pseudarthrosis’ (pseudo-joint). Nonunion is more common in fractures of the scaphoid, the femoral neck and the shin bone (tibia). People who smoke are at higher risk. If the fracture is very mobile or has lost its normal blood supply the risk of nonunion is higher.

Nonunion is often treated by surgery. Bone graft is inserted into the fracture to stimulate healing and the bone ends are held together with internal or external fixation.

Malunion

When the bone heals with deformity, the complication is called malunion. There can be irregularity of the joint surface following an intraarticular fracture, angulation, translation, rotation or shortening as result. If the bone is the wrong shape it throws unusual stress on the next-door joints, increasing the risk of post-traumatic arthritis. Treatment depends on the extent of the deformity and the likelihood of long-term problems. If these are high an operation to correct the deformity may be recommended.

Post-Traumatic Arthritis

Many consequences of fractures impose an unusual stress on joints. Crushing of the joint surface, irregularities after an intraarticular fracture, malunion imposing a stress and scarring inside the joint all dispose the joint to premature wear. The smooth layer of joint surface is worn down and the bone ends rub against each other. This is the process of osteoarthritis but may happen much more quickly after injury. Many aspects of the initial treatment of fractures are aimed at reducing the risk of later osteoarthritis.

Hardware Failure


Metal implants are subject to metal fatigue. You see this commonly when you repeatedly bend or wiggle a piece of wire until it breaks. Fracture fixation is also subject to repeated ‘wiggle’ as micro-movements occur at an unhealed fracture site. Once the fracture has healed this movement stops and the risk of fatigue failure of the fixation is much less. It is a race between the bone healing and the hardware breaking which is usually won by the bone.

However, in situations where healing is delayed, where the fracture is stressed prematurely, where there is a gap between the fracture fragments or where the fixation is weak, fatigue failure may occur and the plate breaks, typically when you do something quite light. In cases of nonunion the fixation always breaks if left long enough.

Hardware failure is usually painful and there may be detectable movement at the fracture site. Trying to use the limb is sore even without any resistance. Management will depend on the situation. If there is evidence of delayed union or nonunion your surgeon may opt to redo the surgery with the addition of bone graft.

Concern about the possibility of hardware failure is the reason why the surgeon and physical therapist warn against doing anything heavy while the bones are still healing. If you have been using the limb for heavy activity and the fixation breaks, it may be possible to obtain healing without further surgery by immobilizing it in a cast. However, if there is a bend at the fracture site this option might not be available.

Impaired function

Function may not be restored to normal after a fracture. As we discussed earlier, the outcome from treatment depends on a large number of factors. In severe injuries, if treatment is prolonged or if there are complications you may not recover full function of the injured limb.

Cosmetic

The appearance of a limb after recovery from a fracture may not be normal even if there is no deformity. Often there is a bony swelling at the site of a healed fracture. In other cases there are scars from surgery or permanent discoloration of the skin.