The expansion of the flat upper end of the tibia which makes up the distal half of the knee joint is known as the tibial plateau. The plateau is an essential part of the weight bearing function of the knee joint and if compromised can severely affect the movement, stability and alignment of the knee, interfering with gait. The fracture should be recognised early and treated accordingly so that the chances of post-traumatic knee arthritis and disability are minimised. Over half the patients in this category are in their fifties or older.
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.
Around 25% of this kind of injury is secondary to a person being hit by a slow speed car at roughly the height of the knee joint, the bumper being the primary contact point. Falling from a height or sporting activities including horse riding can also result in this fracture. A fracture may result from a low energy event or a high energy event, depression fractures being more common from lower energy contacts and splitting fractures more common in higher energy involvement. This type of fracture can present in many complex ways and Schatzker and co workers have proposed a classification into six subtypes which is widely used.
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.
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.
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.
Tibial plateau fractures have as a treatment strategy to restore alignment of the knee joint, re-establish full range of movement, and ensure stability of the knee and anatomical alignment. Overall the knee should be painless, movable and free from arthritis. Strong immobilisation of the fracture by surgery is necessary in unstable joints, with the denser bone of younger people allowing this. Functional bracing and total knee replacement may be necessary in older patients who have reduced bone density.