Final answer:
Indirect signs such as a meniscal avulsion or abnormal joint space on X-rays may indicate a meniscal injury in tibial plateau fractures, though MRI is more effective for diagnosis. The medial and lateral menisci, which provide padding in the knee, vary in mobility and healing capacity due to their structure and vascular supply.
Step-by-step explanation:
The radiographic characteristic that indicates a meniscal injury in tibial plateau fracture films may not be directly visible, as the menisci are fibrocartilage structures that do not typically show up well on X-rays. However, indirect signs of a meniscal tear such as the presence of a small bone fragment within the knee joint, which can result from a discontinuity where the meniscus may attach to the tibia (a 'meniscal avulsion'), can raise suspicion of a meniscal injury associated with a tibial plateau fracture. Additionally, a 'flattening' or absence of the normal space where the meniscus would be positioned or signs of joint effusion may also signal meniscal damage. It is important to note that magnetic resonance imaging (MRI) is far more sensitive than plain radiography for direct visualization of meniscal injury.
Located between the femur and tibia, the medial meniscus and the lateral meniscus provide padding and fill the gap between the femoral condyles and the flattened tibial condyles. The medial meniscus is less mobile due to its attachment to the articular capsule and tibial collateral ligament and, unfortunately, some areas of each meniscus have poor healing capability due to a lack of arterial blood supply. This is an important aspect to consider when diagnosing a meniscal injury.