Why remove both joints?
Gonarthrosis is almost always bilateral, albeit with different severity: the joint that hurts more is not necessarily more changed. A comparative image gives an objective picture on both sides and helps to distinguish normality from pathology - the individual structural features of one person are symmetrical. Such a study is prescribed when planning endoprosthetics, when assessing the dynamics of arthrosis, and in pediatric practice, where comparison with the healthy side is especially important.
X-ray for injury: the first and main method
For any limb injury, radiography remains the first-line investigation. She quickly and accurately answers the key question: is there a fracture, dislocation or displacement of fragments - and all further tactics depend on this.
The image also shows the condition of the joint spaces, bone growths due to arthrosis, areas of bone loss, bone cysts and tumor changes.
Standard - two projections
A fracture without displacement may not be noticeable on one projection: the fracture line coincides with the direction of the beam. The second picture, taken perpendicularly, eliminates this situation. Therefore, in case of injury, a bone or joint is removed in at least two projections, and in doubtful cases, oblique views or a comparative image of the healthy side are added.
What X-rays won't show
- ruptures of ligaments, menisci and tendons
- condition of articular cartilage at an early stage
- bone marrow edema and hidden “stress” fractures in the first days
- soft tissue formations
Shooting with load
A typical X-ray is taken in the supine position, when the joint is unloaded, and the joint space may appear wider than it actually is. Shooting while standing, with support on the leg, shows the joint in working condition - this is how the true degree of narrowing of the gap due to arthrosis, deviation of the axis of the limb and the strength of the ligaments are assessed.