Complications

What are the potential complications of this
fracture?

Nature heals fractures by herself; the focus of treatment of hip fractures is to facilitate this process and avoid the problems (complications) which can arise during the healing process and affect the outcome.

Hip fractures have many and dangerous complications. There is a significant risk of dying after a hip fracture which is greatly affected by the age and existing health status of the patient. Complications of hip fractures can therefore be divided into those that increase the mortality risk and those that primarily affect the fracture.

The management of patients with hip fractures is a team effort with many strange activities, turning, getting patients up when they want to stay in bed, chivvying patients to sit up, breath deeply, cough and move their feet. This account of complications explains the reasons behind these demands.

Some complications actually increase the risk of dying.

Confusion

It is very common for elderly people to become confused after they have been through the stress and shock of a fracture and subsequent major surgery. Doctors recognize two different scenarios when this occurs. The commonest is an exacerbation of pre-existing mild confusion and forgetfulness which affects many elderly people. The strange environment of the hospital, pain and fear may increase this problem and many painkilling medication may cloud the consciousness as well. This usually recovers but sometimes the increased confusion remains evident for some time and prevents the patient from regaining independence. The second type is caused by an acute medical problem such as an infection, biochemical imbalance or heart problem. Here the confusion may be a sign of a more serious underlying problem which must be identified and treated.

Increased confusion is very distressing to the patient's relatives and makes caring for him/her more difficult. The patient is very likely to forget or ignore the restrictions on moving and weight-bearing that protect the healing hip fracture.

Venous thromboembolism VTE

This problem and its treatment is more extensively discussed in the Patient's Guide to Fractures. It is common with hip fractures with Deep Vein Thrombosis (blood clots in the veins) being the usual manifestation. However, Pulmonary Embolism (clot in the lungs) is difficult to detect and may be a contributor to mortality after hip fracture. Because of the extensive surgery the risk of bleeding limits the use of blood thinning medications as a routine after hip fracture surgery.

The main focus for prevention for this complication is mobilizing the patient early and encouraging movements that reduce the risk of blood clots in the legs. Treatment of the established condition is blood-thinning medications, despite the risks.

Chest Infections

Lying down in bed and not moving, affects the inflation of the lungs and predisposes to lung infections (pneumonia). This is another reason to promote mobility after hip fracture. Patients are encouraged to sit up, take deep breaths and cough. The treating team push the patients to achieve some mobility out of concern for these complications, not because they are ignoring the discomfort the patients may be feeling. If a chest infection does occur it is treated with antibiotics and chest physiotherapy.

Stroke or Heart Attack

A stroke is caused by loss of blood supply to a part of the brain. A heart attack occurs if blood supply to the heart muscle is blocked off. If the blood vessels to the brain or the heart are diseased (arteriosclerosis) these events are more likely to occur. After a hip fracture and during surgery the blood pressure may drop and the circulation through diseased blood vessels becomes inadequate.

The anesthetists and surgeons choose techniques to minimize this risk but it cannot be eliminated completely. The treatments for heart attack and stroke are complex and depend on the extent of the damage. They are usually managed by internal medicine specialists.

Some complications affect the healing of the fracture.

Malunion

Where a hip fracture has been treated by internal fixation there is a risk that that fracture will not stay in a good position. The commonest occurrence is shortening but rotation and angulation are also seen. If the fracture heals in an unusual position it is said to be malunited. The result may be a leg shorter by 1/2 inch to an inch or rotated so that the foot turns out. If the hip is painless it would be common to accept this result and use a shoe raise to improve the leg length difference. If the malunion causes significant symptoms then a Total Hip Replacement may be considered to restore normal function.

Nonunion

A fracture of the femoral neck is particularly likely to go on to nonunion - the situation in which the healing process has halted and the fracture will not heal without intervention. In young people with femoral neck fractures this condition would likely be treated by some form of bone grafting procedure and re-fixation in an attempt to obtain healing without sacrificing the hip joint. In the elderly, nonunion would more likely be treated by artificial hip replacement with the aim of getting the patient comfortable and back on their feet quickly.

Nonunion is much less common in Intertrochanteric fractures but the same principles apply. In Subtrochanteric fractures hip replacement is not as good an option, so efforts would be directed to getting the nonunion to heal.

Avascular Necrosis

A fracture of the femoral neck may cut off the blood supply to the femoral head. Even if the fracture heals, the femoral head may die (necrosis), deprived of blood circulation (avascular). This problem is more common in younger patients with a hip fracture and in patients with a nonunion. It may not be evident until months or years after the injury. The dead bone in the femoral head initially stands up to weight-bearing but eventually undergoes fatigue failure and starts to collapse. In some cases the process can be slowed by keeping weight off the hip as the blood supply may be re-establised and the bone grows back. However, most of the time the problem progresses and a hip replacement becomes necessary.

Related Document: A Patient's Guide to Avascular Necrosis of the Hip

Infection

As with all surgery there is a small risk that the wound may become infected. This risk is reduced but not eliminated by giving antibiotics before the surgery and by using appropriate surgical technique. Despite these precautions the surgical site infection rate is about 2% (1/50 cases). Infection is suspected when the wound remains swollen, red and tender and is confirmed by cultures or if pus drains from the wound. The treatment includes antibiotics and may require repeat surgery to drain the infection and make sure it does not take hold in the bone. It is usually better to leave the fixation devices in place until the fracture is healed and then remove them to eliminate all potentially contaminated foreign material from the area.

Hardware failure

The implants used to hold fractures in place have a limited effective lifespan. If the bone does not heal or if the forces acting on the plate and screws are too great, they will eventually break through metal fatigue. The fragile osteoporotic bone found in many patients who have suffered a hip fracture does not hold fixation well either. For these reasons, the fixation fails in a small number of cases. The screws may break or cut out into the joint allowing the fracture to displace. The management of this situation depends on the exact nature of the problem. If the fracture has healed in a satisfactory final position it may not be necessary to do anything. Alternatively the fixation may be removed and replaced or, in severe cases, a hip replacement may be needed.

Other complications affect the health of the patient.

Pressure sores

If you lie on a particular area of skin without moving, the pressure stops the blood circulation to the skin and underlying tissues. If this continues for more than a few hours, these tissues die, forming an ulcer, also known as a bed sore or a decubitus ulcer. They occur on the sacrum at the base of the spine in people who are lying on their backs for a long period; another common site is behind the heel.

Pressure sores may be the result of prolonged immobilization at the scene of the accident that caused the hip fracture. They also arise in hospital if there is a long delay before surgery or after surgery if the patient cannot be mobilized. Lifting and turning the patient reduces the risk. An alternating pressure mattress ensures that the contact areas change regularly and may help prevent this problem. The treatment of pressure sores depends on the extent and depth of the ulcer. In many cases it heals when the patient can be mobilized and weight is shifted off the affected area. At the other extreme, a large deep ulcer may need surgical treatment to effect healing.

Urinary tract infections

These are common anyway in elderly people but made more common after hip fracture by recumbency (lying down), immobilization and the use of bladder catheters. The management usually includes a culture to identify the responsible bacteria and appropriate antibiotics. It is important to prevent the infection from ascending into the kidneys.

Depression

The combination of pain, loss of mobility and the prospect of losing independence is crushing for many patients. At a vulnerable time they may be faced with making key decisions about their future. This type of situational depression is so common and even "reasonable" that the family and treating team may consider it normal. But it is made worse by fears and uncertainty about the future; the patient and family should be told about the outlook, should remain positive and be encouraged to recognize the slow steps towards recovery.

Most patients do heal their fractures and recover mobility. There may be an underlying depressive illness which is exacerbated by the situation. Identifying these elements is important but treating a depression with medication is a difficult problem especially if there is some confusion as well.