CAMRT Radiography Practice Exam

What is the essential projection used to evaluate arthritic knees?

1. AP tangent

2. AP upright (Weight-bearing method)

3. Lateral knee

4. Sunrise view

The correct answer is: AP upright (Weight-bearing method)

The AP upright (weight-bearing method) projection is essential for evaluating arthritic knees because this position allows for assessment of joint surfaces under load, which is particularly important in cases of arthritis. In this view, the knee is positioned straight with the patient standing, permitting visualization of the joint space and alignment while bearing weight. It highlights the relationships between the femur and tibia and can reveal narrowing of the joint space or the presence of osteophytes, which are common in arthritic conditions. This projection also minimizes distortion and optimally demonstrates the changes in joint alignment and condition under realistic, functional loads. Other projections may have their uses, but they do not provide the same direct insight into joint behavior under weight. For example, while the lateral knee can show bony structures and soft tissue, it does not allow for weight-related evaluation. Similarly, the sunrise view focuses on the patellofemoral joint rather than the overall condition of the knee joint crucial for assessing arthritis. The AP tangent view also has specific applications but lacks the full weight-bearing clarity that the AP upright projection offers. Thus, the weight-bearing method is most crucial in diagnosing and assessing the severity of knee arthritis.