Hip fracture is a fracturein the femur(thighbone) just below the hip joint. Most at risk are white, post-menopausal women; Osteoporosisdramatically increases risk. Most hip fractures outside of this group are the result of high-traumainjuries, such as car accidents.
- 1 Definition
- 2 Synonyms
- 2.1 Incidence
- 2.2 Pathogenesis/risk factors
- 2.3 Classification (types of fracture)
- 2.4 Fractured neck of femur
- 2.5 Intertrochanteric fracture
- 2.6 Natural history
- 2.7 Clinical features
- 2.7.1 Symptoms
- 2.7.2 Signs
- 2.8 Investigations
- 2.9 Treatment
- 2.9.1 Non-operative treatment
- 2.10 Operative treatment
- 2.11 Surgery for fractured neck of femur
- 2.12 Surgery for intertrochanteric fracture
- 2.13 Prognosis post operation
- 2.14 Complications
- 2.14.1 Of the injury
- 2.14.2 Of surgery
- 2.14.3 General medical complications
- 2.15 External links
Any fractureof the thigh boneclose to the upper end or involving the hip joint is a hip fracture. In the vast majority of cases a hip fracture is a fragility fracture due to a fall or minor trauma in someone with osteoporotic(weakened) bone. So the subject of "Hip Fracture" sometimes includes the complex consequences of Osteoporosis.
Most of the synonyms actually describe different types of hip fracture. All of these variations are important because each are treated differently.
- Fractured Neck of Femur (sometimes Neck of Femur Fracture or NOF) denotes a fracture adjacent to the femoral head. This acronym(NOF) is sometimes loosely used for Hip Fracture.
- Intertrochanteric or pertrochanteric fracture denotes a fracture which is a few centimeters lower and involves the Greater trochanter
- Fractured Head of Femur or Head Splitting Fracture denotes a fracture involving the head itself. This is rarer and usually the result of high energy trauma and a dislocation of the hip joint.
- Subtrochanteric fracture involves the shaft of the femurimmediately below the Greater Trochanterand may extend down the shaft of the femur.
Approximately 320,000 hospitalizations occur each year due to hipfractures in the USA, with similar proportions in other Western countries.
Most hip fractures occur as a result of falls in elderly patients. For the thigh bone to break in these circumstances means it must be weaker than normal as similar or worse falls in young people do not usually cause the "hip fracture" pattern of injury. The commonest causes of weakness in bones are
- OsteoporosisHip fractures are one of the most serious consequences of osteoporosis; in fact a measure of success or failure of treatment of osteoporosis is the proportion of patients who sustain a hip fracture.
- Other metabolic bone diseases such as Paget's disease, osteomalacia, osteopetrosisand osteogenesis imperfecta. Stress fracturesmay occur in the hip region with metabolic bone disease.
- Benign or malignant primary bone tumoursare rare causes of hip fracture
- Metastaticcancer deposits in the proximal femur may weaken the bone and cause a pathological hip fracture
- Infectionin the bone is a rare cause of hip fracture.
The other major element in the risk of sustaining a hip fracture is the risk of falling. Falls Prevention is an important subject with concerns in the area of providing a safe environment for people at risk, custodial care, walking aids, medication issues etc. Hip Protectors are padded plastic shields that can be placed over the trochantersof people at risk of falling or of sustaining a fragility fracture. They are effective in reducing the likelihood of a hip fracture but it is a challenge to get people to wear them.
Classification (types of fracture)
There are two main types of fracture pattern - intertrochanteric fracture, and fractured neck of femur. The difference is important because the treatment and prognosis are different.
Fractured neck of femur
Fractured neck of femur involves the narrow neck between the round head of the femur and the straighter shaft. This fracture often disrupts the blood supply of the head of the femur - the part that makes up the hip joint.
Garden classified this fracture into four types:
- Type 1 is an undisplaced crack in the femoral neck with no displacement.
- Type 2 is a break across the neck with impaction of the fracture but no displacemet.
- Type 3 involves displacement of the fracture (often rotation and angulation) but still some contact between the two fragments.
- In type 4 there is complete displacement and no contact between the fracture fragments. The blood supply of the femoral head is much more likely to be disrupted in Garden types 3 or 4 fractures.
Surgeons may treat these types of fracture by replacing the bone with a metal prosthetic component cemented into the bone to replace the femoral head. Alternatively the treatment is to reduce the fracture (manipulate the fragments back into a good position) and fix them in place with metal screws or a screw-and-plate device. It has not yet been scientifically established whether one treatment is superior to the other. Image:Nof pauwels3.jpg
Displacement and failure to heal can be problems when the fracture is fixed. Pauwels showed that if the angle of the fracture is too steep the injury is at risk of nonunionor malunion. Another serious complication of a fractured neck of femur is avascular necrosis. The fracture interrupts the blood supply to the head and the bone tissue of the head dies. Unless new living cells migrate into the dead area the femoral head will collapse causing pain and loss of function.
Image:ITfx 31A2.jpgIntertrochanteric fractures occur slightly further down the bone and the fracture line crosses the Inter-trochanteric line between the two trochanters at the upper end of the femur. Because the fracture is lower the blood supply of both fragments is usually intact. This improves the chance of healing and reduces the likelihood of avascular necrosis.
The main concern in the classification of Intertrochanteric Fractures is the stability of the fracture pattern. When the fracture has many fragments (multifragmentary) there is a risk that it will shorten, rotate or angulate before it heals. When the Lesser Trochanter is broken off as a separate fragment the fracture is unstable and likely to collapse.
Hip fractures are very dangerous episodes especially for elderly and frail patients. The risk of dying from the stress of the surgery and the injury in the first few days is about 10%. If the condition is untreated the pain and immobility imposed on the patient increase that risk. Problems such as pressure soresand chest infectionsare all increased by immobility. Eventually the untreated intertrochanteric fracture will heal but with a high likelihood of deformity, shortening of the bone and rotational mal-alignment. Healing of untreated fractured neck of femur is much less certain and displacement even more likely. The untreated prognosis of most hip fractures is very poor.
- History of a provoking episode such as a fall or an accident.
- Pain in the hip region
- Made worse by moving the thigh
- Usually so severe the patient is unable to walk
- May radiate to the knee
- If pain in the hip existed before the fall the patient should be investigated for a Stress fractureor a pathological deposit in the proximal femur.
- The patient's general medical condition must be carefully assessed. It is often necessary to obtain a consultation from an Internistand/or Anaesthetist.
- Risk factors for falling should be evaluated. The patient's social situation needs to be considered.
Signs involving provoking pain should only be elicited when there is doubt about the diagnosis. Usually the diagnosis is obvious and care should be taken to avoid hurting the patient.
- Tenderness and swelling in the proximal thigh
- Pain when the leg is moved or rotated
- Pain on telescoping the limb
- The affected leg is often shortened and externally rotated
- Pulses and sensation are not usually changed by a hip fracture but should be checked.
X-ray of the affected hip usually makes the diagnosis; AP and shoot-through lateral views should be obtained. In the rare situation where a hip fracture is suspected but does not show on plain Xray a CT scan with 3D reconstruction may be helpful. In cases more than 7 days post injury a bone scan may reveal a cryptic fracture.
As the patients most often require an operation, full pre-operative general investigation is required. This would normally include blood tests, ECG and Chest Xray.
If operative treatment is refused or the risks of surgery are considered to be too high the main emphasis of treatment is on pain relief. Skeletal traction may be considered for long term treatment. Aggressive chest physiotherapyis needed to reduce the risk of pneumoniaand skilled nursing to try to avoid pressure soresand DVT/pulmonary embolismMost patients will be bedbound for several months.
Most hip fractures in elderly people are treated by surgery. This is so even though the surgery is a major stress on the patient. The injury is so painful that the patients suffer significantly and have to remain immobilized. It is considered that prolonged immobilization is more dangerous to the health of the patients than the surgery.
Surgery for fractured neck of femur
For low grade fractures (Garden types 1 & 2) the standard treatment is fixation of the fracture in situ with screws or a sliding screw/plate device. This treatment can also be offered for displaced fractures after the fracture has been reduced.
In elderly patients with displaced fractures many surgeons prefer to undertake a Hemiarthroplasty, replacing the broken part of the bone with a metal implant. The advantage is that the patient can mobilize without having to wait for healing.
Surgery for intertrochanteric fracture
This fracture has a good chance of healing and treatment involves stabilising the fracture with a lag screw and plate device which hold the two fragments in position while healing occurs.
Prognosis post operation
Among those affected over the age of 65, 40% are transferred directly to long-term care facilities, long-term rehabilition facilities, or nursing homes; most of those affected require some sort of living assistance from family or home-care providers. 50% permanently require walkers, canes, or some other such device for mobility; all require some sort of mobility assistance throughout the healing process.
Among those affected over the age of 50, approximately 25% die within the next year due to complications such as blood clots(deep venous thrombosis, pulmonary embolism), infections, and pneumonia.
Of the injury
- Nonunion - failure of the fracture to healThis is common (20%) in Fractured Neck of Femur fractures but much more rare with other types of hip fracture. The rate of nonunion is increased if the fracture is not treated surgically to immobilize the bone fragments
- Malunion - the fracture heals in a distorted position. This is very common. Shortening, varus deformity, valgus deformity and rotational malunion all occur quite often because the fracture may be unstable and collapse before it heals. With patients of limited independence and mobility this may not need to be treated but the intention of treatment is to prevent such problems.
- Avascular Necrosisof the Femoral Head - this occurs frequently (20%) in Neck of Femur fractures because the blood supply is interrupted. It is rare after Intertrochanteric Fractures.
- Neurological and vascular injury as a result of the injury are rare
- Infection - deep or superficial wound infection has an approximate incidence of 2%. It is a serious problem as superficial infection may lead to deep infection. This may cause infection of the healing bone and contamination of the implants. It is difficult to eliminate infection in the presence of metal foreign bodies such as implants. Bacteria inside the implants are inaccessible to the bodies defence system and to antibiotics. The management is to attempt to suppress the infection with drainage and antibiotics until the bone is healed. Then the implant should be removed, following which the infection may clear up.
- Implant failure - The metal screws and plate can break, back out or cutout superiorly and enter the joint. This occurs either through inaccurate placing of the implant or because the bone is so weak and brittle that the fixation does not hold. In some cases it may be necessary to revise to a Total Hip; in others the surgery may need to be re-done.
- Mal-positioning - the fracture can be fixed and subsequently heal in an incorrect position; especially rotation. This may not be a severe problem or may require subsequent Osteotomysurgery for correction.
General medical complications
Many of these patients are unwell before they fall and break theirs hips. For some, the fall is part of the illness. Nevertheless the stress of the injury and the surgery does increase the risk of medical illness
- Heart attack
- Chest infection
- Blood clots
- Deep venous thrombosis(DVT) is when the blood in the leg veins clots and causes pain and swelling. This is very common after hip fracture as the circulation is stagnant and the blood is hypercoagulable as a response to injury. DVT can occur without causing symptoms.
- Pulmonary embolism(PE) occurs when clotted blood from a DVT comes loose from the leg veins and passes up to the lungs. Circulation to parts of the lungs are cut off which can be very dangerous. Fatal PE may have an incidence of 2% after hip fracture and may contribute to illness and mortality in other cases.
- Mental confusion- this is extremely common following a hip fracture. It usually clears completely but the disorienting experience of pain, immobility, loss of independence, moving to a strange place, surgery and drugs combine to cause or accentuate dementia.
- Urinary Tract Infection(UTI) - Patients are immobilized and in bed for many days. They are frequently catheterised and UTIs are common.
- Pressure sores- Prolonged immobilization and difficulty moving make it difficult to avoid pressure sores on the sacrum and heels of patients with hip fractures. Early mobilization is advocated to avoid this. Alternating pressure mattresses should be used for those unable to mobilize.
- Orthopedics.com article on hip fractures
- American Academy of Orthopedic Surgeons article on hip fractures
- Fractures of the Femoral NeckWheeless Textbook of Orthopaedics
- Intertrochanteric FracturesWheeless' Textbook of Orthopaedics
Categories: Fractures| Orthopedics
This article is licensed under the GNU Free Documentation License.
It uses material from the http://en.wikipedia.org/wiki/Hip+fracture Wikipedia article Hip fracture.