Fractures of the thigh bone (femur), close to the knee, are a common injury in children and the elderly. This type of fracture, a distal femoral fracture, also may also occur in people who have undergone total knee or hip arthroplasty, knee or hip replacement. Generally, management of such fractures can be difficult because of how the bone can break and the damage that results. The authors of this article reviewed new techniques to treat the distal femoral fracture and new information on the outcomes, complications, and rehabilitation.
The first step in properly treating the fracture is obtaining clear x-rays of both anteroposterior and lateral (front and side) views. If the ends of the bone have overlapped, a traction x-ray may be important. Computed tomography (CT) scans can also be helpful in helping diagnose the severity of the fracture.
The fractures, once diagnosed, are classified:
– “A” fractures are extra-articular, or outside the joint
– “B” fractures are partial articular
– “C” fractures are supracondylar or intercondylar, a break right through the bone or in the notch of the femur
The C fractures are divided into C1, which are not comminuted, not crushed or splintered, C2, which are metaphyseal comminuted, where the bone wider part of the bone is shortened because of the fracture, and C3, which has shortening from the bone fracture and from the joint.
The type of surgery and hardware used depends on what type of break has occurred and how severe it is. Surgery is almost always the way to treat this fracture, non-operative treatment is the exception rather than the rule. This could only be if the fracture is relatively stable in patient who is nonambulatory, does not move about, or has significant illnesses that would make surgery dangerous.
Generally, surgery involves using nails and/or plates to stabilize the bone. Nails allow better movement, usually, but most often just above the joint. Plates, on the other hand, are used in the distal part of the bone (closer to the knee) and can be used in conjunction with screws. There are several types of blades that can be used: locking blade plates, locked internal fixator, and locking periarticular plates. The blade plate, although useful, can be difficult to use for many surgeons. The newer locking plates are used more often.
The submuscular locking plating has replaced open plating, for the most part. The plate is passed under the muscle and fixed to the bone. This procedure has a low nonunion and infection rate.
Another type of implant, the fixed-angle implant, stabilizes the bone and multiplanar fixed angle screws offer more support. However, they are more complex to use, expensive, and they have a higher risk of malunion. Along the same lines, the locked internal fixator plate has a higher loss of fixation than does the blade plate, particularly in osteoporotic bone, bone that has lost bone mass. On the other hand, the locked internal fixator plate has been successfully used in complex fractures and fractures that occurred above a knee arthroplasty.
Intramedullary nailing, placing nail inside the bone is a good option for many distal femoral fractures. Antegrade nails, ones that lock forward, may be used at or above the wider part of the bone, while type B fractures may be stabilized with percutaneous lag screws, before nails are inserted. Another type of nails, retrograde lag nails, ones that go across the bone, are used for more severe fractures.
When a fracture occurs just above a total knee, both retrograde nails and locking plate can be used. However, the nailing could cause damage to the prosthetic knee or could cause some debris to enter the joint area. As well, some of the knees may not be designed to be able to accommodate such a nail. The locked plate, on the other hand, fixes the area well, is less invasive a surgery, and does not interfere with existing prosthetics.
In studies that examined the effectiveness of the locking plates in fractures just above a knee prosthesis, 19 of 22 healed without incident. The three other patients who had non-unions were obese and were taking insulin for diabetes. Two developed infections, as well.
In rehabilitation, the authors wrote that patients should get out of bed as soon as possible after their surgery because the earlier they can move the knee, the better. However, mobilizing does not necessarily mean bearing weight on the affected leg, which may take a while, depending on how the break was, the strength of the patient’s bone, and the patient’s needs.
For some patients, with non-articular fractures, toe-touching may be possible – with crutches – for the first four to six seeks of recovery, followed by progressive weight bearing. Aggressive range-of-motion exercises for the knee should begin as soon as is possible, as well as strengthening exercises for the quadriceps, the thigh muscles.
The authors concluded that orthopedic surgeons must be kept up-to-date on the latest techniques available to repair distal femoral fractures for the best outcomes for the patients.