The tibial plateau is the flat, expanded top of the shin bone or tibia which makes up the lower half of the knee joint. It is a very important part of the body for load bearing and any disruption of this area can cause abnormalities in alignment of the knee, knee stability and movement especially weight bearing and walking. Early recognition and treatment of this injury is vital to avoid the potential disability which could ensue and the longer term consequences of knee arthritis. More than half the sufferers from this fracture are over fifty years of age.
A large group which suffer this type of fracture is older women who already have some degrees of osteoporotic change in the area. Younger people with this presentation more likely result from more high energy events. The usual way these fractures occur is for a sideways force to be applied to the knee (often in a knock knee direction) while the knee is weight bearing with a downward force also applied. The lateral condyle (most commonly) is then squashed down by the large femoral condyle on that side. Sports injuries and falling from a height can result in this injury but it is much more common secondary to a road accident.
Pedestrians who are hit by the bumper of a car in slow speed events make up about a quarter of this patient group as the bumper is at the right height to apply the required forces. Sporting events such as horse riding or falls from a height can also cause this type of fracture. The levels of energy involved in the precipitating events can make a significant difference to the types of fracture which result. Lower energy events more typically cause depression fractures whilst the result of a higher energy occurrence is more likely to be a splitting fracture. The complex nature of these fractures has resulted in many efforts at classification, with Schatzker and co-workers' now accepted.
Patient assessment does not concentrate solely on the state of the bony structures but includes the soft tissues in the local area including nerves, muscles and blood vessels. Cruciate ligament and cartilage (meniscal) injuries accompany around half of the number of tibial plateau fractures and these may require separate surgical intervention. The medial collateral ligament, on the inside of the knee joint, is more at risk from the injuring forces as they often hit the knee laterally and force it into a knock knee position. More severe events can fracture the medial plateau and this is accompanied by higher rates of soft tissue damage.
A range of displacements of the fracture may be acceptable for conservative, non operation, treatment but if the fracture is depressed more than five millimetres the surgeon may decide to lift up the joint surface and bone graft below it. Surgery is essential in fractures to this area which are open (there is a wound connecting to the fracture), cases where compartment syndrome is present and evidence of damage to the blood vessels. Operation is not advised in cases where the fracture is not severe enough and where the soft tissues are too badly damaged to make internal fixation wise.
On establishing the diagnoses the management plan can begin and this includes treatments aimed at limiting swelling and inflammation such as keeping the part still, resting, elevating the leg and compression of the area. Debridement, the surgical removal of any dying or dead tissue, is essential to ensure the well being of the remaining healthy tissue. Compartment syndrome, where higher and higher pressures develop in the leg compartments, is an emergency for which fasciotomy (surgical release of the tissues) is indicated.
Treatment of fractures of the tibial plateau is aimed at restoring the stability of the knee joint, its correct alignment and anatomical relationships of the joint along with full movement in the knee so the knee will function well, is painless and will not suffer arthritic change. If the joint is unstable then surgery will have to be performed, holding the fragments with as little movement as possible. In younger patients with good bone quality then internal fixation may be successful, however older patients with poor bone quality may need to be functionally braced or have total knee replacement.
