Femur fracture: description
In a femur fracture, the longest bone in the body is broken. Such an injury rarely occurs alone, but usually as part of extensive trauma, such as that caused by serious car accidents.
The thigh bone (femur) consists of a long shaft and a short neck, which also carries the ball of the hip joint. In the area of the shaft, the femur is very stable. The greater trochanter, a bony prominence on the outside between the femoral neck and the shaft, serves as a muscle attachment point. The lesser trochanter is a small bony prominence on the inside of the femur.
Depending on the location of the fracture gap, there are the following types of femoral fractures:
- Femoral neck fracture
- Pertrochanteric femur fracture
- Subtrochanteric femur fracture
- Femur fracture near the hip joint (proximal femur fracture)
- Femoral shaft fracture
- Knee joint proximal femur fracture
- Periprosthetic femur fracture
In the following, all fracture types are considered in more detail – with the exception of the femoral neck fracture. This is discussed in more detail in the article Femoral neck fracture.
Pertrochanteric and subtrochanteric femur fracture
The so-called subtrochanteric femur fracture is a fracture below the trochanters on the shaft of the femur and shows approximately the same characteristics as a pertrochanteric femur fracture.
Proximal femur fracture.
In 70 percent of all femur fractures, the fracture is a proximal femur fracture. In this case, the fracture gap is located further up the shaft near the hip joint. In this type of femur fracture, the upper bone fragment is rotated outward by the muscles.
Femoral shaft fracture
Surrounding the femur is a strong soft tissue mantle consisting of quadriceps muscles in the front and ischiocrural muscles in the back. On the inner side are additional muscles, the adductor group. Depending on the location of the femur fracture, the muscles move the bone elements in a certain direction.
Knee joint (distal) femur fracture
The distal femur fracture (also supracondylar femur fracture) is located on the shaft near the knee joint (up to 15 centimeters above the knee joint line). In this case, the upper bone fragment is pulled to the inside and the lower fragment is pushed backwards.
A periprosthetic femur fracture is when the femur is anchored in a prosthesis, such as a hip or knee prosthesis, and the fracture is above or below the prosthesis. Because there are more and more people with such prostheses, the incidence of periprosthetic femur fractures is also increasing.
Femur fracture: symptoms
A femur fracture is very painful. The affected leg cannot be loaded, swells and shows a deformity. An open fracture often develops – in this case, the skin is injured by bone splinters.
The immediate measure at the scene of the accident is to position the leg as painlessly as possible and to splint it. In the case of an open femur fracture, it is best to cover the wound with a sterile dressing until the patient arrives at the hospital.
A femur fracture can cause major bleeding, possibly resulting in circulatory shock. Symptoms of this include cold sweaty skin with a pale, grayish color. Regardless of the ambient temperature, sufferers shiver and shiver, and their hands and feet are cold.
Symptoms of femoral shaft fracture
Symptoms of hip joint proximal femur fracture
In proximal femur fracture, the leg appears shortened and is rotated outward. Affected individuals also describe pain from compression and pain in the groin.
Symptoms of a femur fracture near the knee joint (distal)
Obvious fracture signs in a distal femur fracture include bruising and swelling, and possibly malalignment of the leg. The knee cannot be moved. In addition, there is very severe pain.
Symptoms of per- and subtrochanteric femur fracture
A typical symptom of a pertrochanteric femur fracture is a shortened and outwardly rotated leg. The affected person is unsteady when walking and standing. The leg cannot be moved because of the severe pain. Sometimes a bruise or bruise mark is seen.
Subtrochanteric femur fracture shows the same symptoms as pertrochanteric fracture.
Symptoms of periprosthetic femur fracture
A periprosthetic femoral fracture may present with symptoms similar to a normal femoral fracture, depending on the location of the fracture. The fracture may occur around the greater trochanter, the shaft, and near the knee joint.
A femur fracture occurs when strong forces act on the bone. Traffic accidents, for example, are frequent causes of a femur fracture. Younger people are usually affected. In older people, the femur fracture usually occurs near the knee joint or the femoral neck. Osteoporosis, in which the bone is decalcified, plays a major role. Unlike femur fracture, femoral neck fracture occurs with even minor falls.
Femoral shaft fracture
Hip joint (proximal) femur fracture
Proximal femur fracture is a typical fracture of the elderly. The cause of the accident is usually a fall at home.
Knee joint (distal) femur fracture
Accident mechanism in distal femur fracture is often a razor trauma (high razor trauma) – a lot of kinetic energy (kinetic energy) acts on the bone. The result is usually a larger zone of comminution, often involving joints, capsules as well as ligaments. However, elderly people with osteoporosis can also suffer a distal femur fracture, in which case it is usually a simple fracture.
Per- and subtrochanteric femur fracture
Both pertrochanteric and subtrochanteric femur fractures typically occur in the elderly. The cause is usually a fall on the hip.
Periprosthetic femur fracture
The cause of a periprosthetic femur fracture is usually a fall or accident. Risk factors are:
- diseases such as osteoporosis
- incorrect position of the stem in the prosthesis
- incomplete cement mantle
- bone tissue disintegrating (osteolysis)
- loosened prosthesis
- repeated joint replacement
Femur fracture: examinations and diagnosis
A femur fracture can be life-threatening in the most extreme cases, so if you suspect such a fracture, you should immediately call the family doctor’s emergency service or your family doctor. The specialist for bone fractures is the doctor of orthopedics and trauma surgery.
Medical history
The first step in making a diagnosis is a detailed conversation in which the doctor asks exactly how the accident happened and your medical history (anamnesis). Possible questions are:
- How did the accident occur?
- Was there direct or indirect trauma?
- Where is the possible fracture located?
- How do you describe the pain?
- Were there any previous injuries or previous damage?
- Have there been any previous complaints such as load-related pain?
Physical examination
Apparative diagnostics
An X-ray confirms the diagnosis. The entire thigh with its adjacent joints is x-rayed to assess the fracture more precisely. Images of the pelvis, hip joint and knee are also taken in two planes.
In the case of comminuted or defect fractures, a comparative image of the opposite side is usually taken for further treatment planning. If vascular injury is suspected, Doppler sonography – a form of ultrasound – or angiography (vascular x-ray) may be helpful.
Femur fracture: Treatment
The leg should be splinted and carefully lengthened while still at the scene of the accident. Therapy in the hospital usually consists of surgically stabilizing the leg. To do this, the fracture must be set up anatomically precisely and the axis and rotation restored without loss of function.
Femoral shaft fracture
A femoral shaft fracture is usually operated on. The technique usually chosen is the so-called locking intramedullary nailing. This generally allows the femur to heal more quickly and can be loaded sooner. In addition, only a few soft tissues are injured during the operation.
After the operation, the doctor tests the stability of the knee joint. This is especially important in younger patients with a femur fracture caused by a high-rasan trauma, because cruciate ligaments on the knee were often injured in the process.
Femoral shaft fracture in children
In newborns, infants and young children with a femoral shaft fracture, doctors first try conservative treatment. A closed fracture can be immobilized with a pelvic-leg cast or with what is called “overheadextension” (pulling the leg up vertically) performed in the hospital for about four weeks. In rare cases, surgery is considered.
In school-age children, surgery is preferable for a femoral shaft fracture. A pelvic cast encounters difficulties in home care at this age. Extension is equally difficult to perform because of the length of time in the hospital and the inconvenience. Depending on the injury, “external fixator” is the primary treatment and elastic stable intramedullary nailing (ESIN) is performed in more uncomplicated cases.
Hip joint (proximal) femur fracture
Femur fracture close to the knee joint (distal).
In the case of a femur fracture near the knee joint or involvement of the articular surface, it is important to realign the bone exactly anatomically. This is the only way to obtain a good functional result.
In conventional procedures, the fracture is stabilized with angle plates and the dynamic condylar screw (DCS). However, newer procedures are gradually gaining acceptance: The so-called retrograde technique of intramedullary nail osteosynthesis and inserted plate systems, in which the screws are anchored in the plate in an angle-stable manner, are showing good success.
Per- and subtrochanteric femur fracture
Periprosthetic femur fracture
Surgery is also preferable to conservative therapy for periprosthetic femoral fracture. Depending on the type of fracture, various operations such as prosthesis replacement, plate osteosynthesis or retrograde nailing are used.
Aftercare for femur fractures
Aftercare depends on how severe the injuries are and how stable the osteosynthesis is. After surgery, the leg is placed on a foam splint until the wound drainage is removed. Two days after surgery, passive motion therapy is started with the so-called CPM motion splint. Depending on the progress of the femur fracture and the implant, the leg can slowly be partially loaded again. The amount of weight bearing depends on how much callus (new bone tissue) has formed. This is checked on an X-ray. After about two years, the plates and screws are surgically removed.
Femur fracture: course of the disease and prognosis
In individual cases, the prognosis of a femoral fracture depends largely on the type and extent of the fracture.
For example, the prognosis after treatment of femoral shaft fracture is very good. About 90 percent of cases heal within three to four months without permanent damage. If the bone heals poorly, intramedullary nail osteosynthesis can remove the locking pin and attach autologous (the body’s own) cancellous bone (spongy tissue inside a bone). This stimulus can accelerate bone healing.
Fracture of the femur near the hip joint (proximal) usually occurs in elderly people after a fall. Some affected individuals are unable to bear full weight on the leg even after treatment is complete and then have limited mobility. The patient may require nursing care.
In the case of a femur fracture near the knee joint (distal), the patient can begin exercises early after surgery. The leg can usually be fully weight-bearing again after about twelve weeks.
In the case of a pertrochanteric femur fracture, the patient can resume full use of his or her leg immediately after surgery.
Complications
- Positional damage
- Compartment syndrome
- Deep iliac vein thrombosis (DVT)
- Infections, especially in the medullary cavity (especially in open femur fractures)
- Pseudarthrosis (formation of a “false joint” between the fracture ends)
- Axial malalignment
- Rotational malposition (especially in intramedullary nail osteosynthesis)
- Leg shortening
- ARDS (acute respiraotry distress syndrome): acute damage to the lungs; possible complication if the femur fracture is part of a severe multiple injury (polytrauma)