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.
This fracture is more common in older women which reflects the increased incidence of osteoporotic changes in these patients. If this fracture occurs in younger people then it is likely to be secondary to more energetic injuries. The typical method of fracture in tibial plateau fractures is a force applied to the knee in a knock knee direction with weight bearing loads applied at the same time. The lateral condyle of the femur compresses down on the tibial plateau on the outside and crushes down the bone on that side. Many injuries are related to motor vehicle injuries with a smaller number deriving from sport.
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.
Assessment of the patient will not only include the state of the bone but the condition of the soft tissues which can also be damaged, the blood vessels, nerves and muscles. Tibial plateau fractures are accompanied in about 50% of cases by damage to the knee menisci (cartilages) and the cruciate ligaments which may require surgery. The medial collateral ligament, the ligament on the inside of the knee, is more vulnerable to damage due to the incident forces being more typically on the outside of the knee in a knock knee direction. Medial plateau fractures result from bigger events as the bone is stronger on that side, with more frequent soft tissue problems.
It may be appropriate to accept a number of fracture displacement types for non-operative or conservative treatment but if the fracture depression is over 5 millimetres it may be decided to raise up the depressed surface and place a bone graft under it. If the fracture is an open one (with an open wound) then surgery will be required, as it will in cases of damage to the vascular system and in the case of the development of compartment syndrome. If the fracture is not severe then it should be treated conservatively and operation may be avoided, at least temporarily, in cases where extensive soft tissue damage threatens tissue integrity.
With the diagnosis established the treatment plan can begin with treatment modalities targeted at lowering oedema and inflammation, including limb elevation, tissue compression, immobilisation of the area and resting the part. The removal by surgery of any non-viable dead and dying tissues (debridement) is vital to safeguard the remaining healthy tissues. Fasciotomy may be required to release excessive pressure from one or more of the leg compartments should compartment syndrome threaten the viability of the limb.
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.
Jonathan Blood Smyth, editor of the Physiotherapy Site, writes articles about physiotherapy, physiotherapy, Physiotherapists in Bournemouth, back pain, orthopaedic conditions, neck pain and injury management. Jonathan is a superintendant physiotherapist at an NHS hospital in the South-West of the UK.