Injuries involving any joint tend to be problematic injuries. Fractures involving a broken knee are no exception. We will discuss here a number of the most common types of fracture involved in the group of injuries that may be termed a broken knee.
Fractures of the Femoral Condyles
Such injuries are not massively common. They often result from high velocity injuries such as in road traffic accidents. Bones do not break easily under normal circumstances and to break the femur in this area underlines this.
The femoral condyles are the large bony protrusions above the knee joint. The break may be above or between them and can go into the joint itself. Where the fracture goes into the joint the problems will generally be greater because the function of the knee itself is likely to be permanently affected.
Whether the fracture extends into the joint or not it is very likely that the knee will be affected in some way due to the altered mechanics, caused by even minor changes in the healed or fixed position of the fracture and/or the leaked blood together with inflammation and tissue exudate from the fracture that finds its way into the joint causing limitation to the movement.
Often difficult to internally fix, such fractures with achievement of good alignment, are treated in a cast brace. This is a cast or a plaster with a hinge at the knee to allow movement thus preventing joint stiffness and muscle wasting that results from periods of immobility.
Rehabilitation involves a lot of work to obtain as much knee movement and muscle power as possible.
Fractures of the Tibial Plateau
Fractures involving the knee of this type invariably result in some loss of movement in the joint. Falls and road traffic accidents are common causes of such injuries.
They are usually successfully treated with fixation in a cast brace (hinged plaster or lightweight cast that allows for knee movement) as long as there is satisfactory positioning of the broken bone.
Rehabilitation of such injuries can take many months to achieve maximum return of movement in the knee. There is very likely to be a loss of movement, particularly affecting the ability to fully extend or straighten the knee. This has a marked affect on normal walking function.
Fractures of the Patella
Fractures involving the knee cap or patella often result from road traffic accidents where there is a direct blow to the bone or from sudden, forced contraction of the quadriceps muscle in a fall or trip situation. The contraction can be so strong as to pull the patella apart, splitting it into two.
This type of fracture is commonly treated by wiring the broken knee cap together with what is known as tension band wiring. The wire will often be left in place indefinitely unless it becomes troublesome, as it sometimes can being so near to the skin overlying it.
Rehabilitation involves a good degree of work getting the knee flexion or bend again as well as returning the strength to the quadriceps.