Tibial Plateau Fractures
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.
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.
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.
Surgeons may be happy to accept a range of fracture displacement and pursue conservative or non-operative management in these cases. Lifting the depressed plateau and securing bone graft underneath it may be required if depression exceeds 5mm in depth. Open fractures, where a wound is continuous with the fracture, mean that surgery will be needed, as it is also if the blood supply has been compromised by vessel damage or if compartment syndrome has developed in the lower leg. Less severe fractures can be conservatively managed and if there is severe soft tissue compromise then surgery may have to be postponed.
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.
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.
Jonathan Blood Smyth, editor of the Physiotherapy Site, writes articles about physiotherapy, physiotherapy, Physiotherapists in Coventry, 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.