Fractures of the shaft of the femur

Fractures of the shaft of the femur can occur in any age group. In young children the spiral fracture of the femur is one of the fractures which occurs commonly in nonaccidental injury but rarely at any other time. The force required to cause a spiral fracture of a child’s femur is so great that it is unlikely that the child can exert this force by falling. In the adult a shaft fracture of femur is usually associated with a high-energy injury such as a motorcycle crash. In the elderly this fracture is again associated with pathological fractures secondary to a lytic lesion. It is unusual for this fracture to be associated with neurovascular damage, but in a high-velocity accident in a young adult this must always be born in mind.

Causes of fractures of the shaft of the femur

  In children, may be nonaccidental injury

  In adolescents, usually high-velocity injury

  In the elderly, may be pathological

Treatment in children

This fracture heals very quickly in children and the fracture can be stabilised with nonoperative means (Fig. 23.24). In children under the age of 2 years, vertical skin traction can be used to hang the legs off the bed. Static traction can be used and the legs raised until the child’s bottom is floating just off the bed. Surprisingly, the children do not find this traction uncomfortable and nursing is easy. It is easy to tell when the fracture has united as the child starts spinning around and hanging off the bed by its legs. In the young child the femur is capable of considerable remodelling, so a perfect reduction is not necessary.

Treatment of fractured shaft of femur

  In infants — gallows traction

In children and adolescents — balanced traction

  In adults and the elderly — locked nail

Treatment of the fractured shaft of femur in the child before epiphyseal closure

If there is still growth potential in the femur then internal fixation should be avoided as this may cause damage to the epiphyseal growth plate. The majority of growth in the femur occurs in the distal epiphysis, but nevertheless both should be protected if at all possible. A fractured femur in an adolescent can be managed on Hamilton Russell balanced traction or on static traction using a Thomas splint, but in this case it is wise to use a Fisk hinged knee piece to allow early mobilisation of the knee joint to prevent stiffness in the knee (Fig. 23.25). If traction is applied through a tibial pin, care must be taken not to apply the traction for too long as there is a risk of causing stretching of the ligaments around the knee. This produces a permanently lax and unstable knee (a frame knee). As soon as the fracture is sticky, there may be place for taking the child off traction and putting the leg into a cast brace with knee hinges so that they can start mobilising. Great care must be taken to watch that the femur does not fall into varus at this stage. Initially, weekly check X-rays will be needed.

Treatment of fractured femur in the adult

Traction for fractured mid-shaft femur can also be used in the adult but requires that the patient stay in bed for 12—16 weeks. Once the fracture has been settled into a satisfactory position there is no reason why the last weeks of this traction should not be carried on at home where the patient can be nursed by his or her family (Fig. 23.26). Traction may also offer some advantages when the fracture is open and the femur heavily contaminated. There will inevitably be an increased risk of infection if plating or an intramedullary nail is used, and it may be advisible to leave the patient on traction at least for a few days until the wound has settled down. However, this is not an excuse for failing to be aggressive about removing all contaminated tissue from the wound at the time of the accident (débridement). The wound should be left open, and re-exploring and clearing away of dead or contaminated tissue should continue until the wound is clean. An external fixator can be applied to the lateral side of   the femur to stabilise the fracture but the thick muscles overlying the bone can produce problems with pin tract infections. Internal fixation of the femur can be performed either with a plate or with an intramedullary nail.

If a plate is to be used then it should be very heavy duty and the exposure will need to be extensive, as there will need to be at least four holes for fixation of the plate above the fracture and four holes below the fracture. If the fracture is spiral then lag screws will need to be placed to draw the fragments together, either through or separate from the plate. If the medial cortex is deficient then this will need to be buttressed with bone graft and great care will need to be taken when mobilising the femur as the plate will be vulnerable to bending loads. The femoral shaft is ideally suited to an intramedullary nail which, if the equipment and expertise is available, can be introduced closed from the proximal end and then locked both proximally and distally. This will give adequate stability to both bending and rotation forces to allow the patient to weight-bear immediately (partial weight-bearing if it is an unreamed nail) and to leave hospital as soon as they have recovered from the surgery and are able to walk safely. The operation must be performed with great care as the complication rate even in the best hands is high. The common complications are listed in Table 23.7.

Alternatives to intramedullary nailing

A simpler alternative to intramedullary nailing is the use of rush pins introduced through the lateral and/or medial condyles of the femur. Rush pins are flexible rods which can be passed into the femur through a small skin incision at the knee and which are slightly curved so that by twisting them they can be used to cross the fracture site and pass up into the femoral neck. The femur can be stacked with rush nails until a relatively tight fixation is obtained. Four or five rush nails passed up the femur are not as strong as an intramedullary nail and are particularly poor at controlling rotation. They do, however, prevent translation at the fracture site but do not prevent impaction. Although they are relatively simple to insert they do tend to back out, and a patient should certainly not be encouraged to more than toe touch with the leg until the fracture has started to unite.

Metastases in the femur which have not yet fractured

Wherever possible, secondaries in the femur or any other long bone should be referred to an orthopaedic department before the pathological fracture occurs. They are much easier to man­age at this stage than they are after the fracture has occurred through the lytic lesion. It is said that the femur is at imminent risk of pathological fracture if a lytic lesion has eroded more than half the thickness of the cortex or there is erosion over more than 2 cm of the cortex. If either of these signs is present then immediate action needs to be taken to stabilise the femur before it breaks. Before embarking on surgery X-rays should be taken of the whole length of both femurs as there is likely to be more than one metastatic lesion and this may affect the choice of surgery. The purpose of the surgery is to fix the bones so that they do not break, so that the last weeks or months of the patient’s life are not spent in pain and disabled. However, the patient must be warned of the risks of the surgery which are high (particularly death from pulmonary embolus). As soon as the bones are fixed the patient can be transferred back to medical care for radiotherapy or cytotoxic drugs, depending on the most appropriate management.

Indications for prophylactic fixing of lytic lesions in the femur

     50 per cent of the cortex eroded

     > 2 cm invaded

Check for other lesions

Supracondylar fractures of the femur

Supracondylar fractures occur in young adults involved in very high-energy accidents or in the elderly who fall awkwardly. There are many different patterns of fracture, but not uncommonly a fracture line enters the knee joint through the intercondylar notch creating an unstable Y­shaped fracture. The X-rays may be difficult to interpret because the fracture line down into the knee joint may be hidden behind the patella but a careful check must be made for this as it alters the surgery required. In the elderly neurovascular compromise is unusual, but in the young high-velocity accident the popliteal vessels and nerves lie close to the fracture and may easily be damaged.

The nonoperative management of the supracondylar fracture of the femur

This fracture is normally unstable. It is too close to the knee joint to manage in plaster and even in traction the distal fragment tends to flex. If it is not possible to move the knee early the gastrocnemius tends to become tethered down to the fracture site and permanent stiffness in the knee results. The nonoperative management of the supracondylar fracture therefore tends to end with a malunion and a stiff knee.

Operative management of supracondylar fractures

Special plates have been designed for the management of supracondylar fractures, and it is a fracture where preoperative planning, of drawing out of the fragments on tracing paper and then fitting templates to the reduced fragments allows a logical operation to be designed.

If there is an intercondylar fracture this may need to be fixed first with large lag screws and then a blade plate introduced to attach the distal fragment to the proximal. Bone grafting may be needed on the medial side if there is a defect. Internal fixation allows early mobilisation of the knee but weight-bearing may need to be protected with a cast brace until union has been achieved.

  Supracondylar and intracondylar fractures of femur

  Check carefully for extra fracture lines

  Nonoperative treatments lead to malunion and stiffness

Plan surgery with templates drawn on to tracings of X-rays

Mobilise early