Standing AP (weight‑bearing) knee: patient stands erect with knees fully extended, feet shoulder‑width apart and toes pointing forward, weight equally distributed. The detector is centered at the knee joint and the central ray is directed perpendicular to the joint space, about 1 cm below the patellar apex, to include distal femur and proximal tibia/fibula. Immobilize to avoid motion.

Standing (weight-bearing) knee X-rays assess joint space and alignment under load, helping diagnose osteoarthritis by showing joint-space narrowing, cartilage loss, osteophytes, and subchondral sclerosis. They reveal varus/valgus malalignment, help detect fractures or joint effusions, evaluate prostheses and deformities, and guide treatment planning by demonstrating functional load-related changes not visible on non-weight-bearing films.

Knee AP X‑ray costs vary by country and setting. In India it’s typically ₹150–800 (~$2–10) at radiology centers. In the UK it’s free on the NHS; private clinics charge roughly £40–120 (~$50–150). In the US expect about $50–300 for a single‑view X‑ray in outpatient settings; hospital/ER or bundled facility fees can raise costs to several hundred dollars.

A standing AP (anteroposterior) and lateral view are X‑ray projections taken with the patient upright so the limb or spine bears weight. The AP image travels front‑to‑back to show joint alignment and spacing; the lateral is a side view showing depth and sagittal alignment. Weight‑bearing views better reveal joint space loss, instability or deformity, commonly used for knees, ankles and spine.

Stand with knees soft, not fully locked or hyperextended, maintaining a slight bend to engage muscles and absorb shock. Align knees over the middle of your feet, tracking in line with the toes without collapsing inward or bowing outward. Distribute weight evenly between feet, keep hips level and ankles neutral. This protects cartilage and ligaments and reduces joint strain.

AP (anteroposterior) and lateral radiographic views are both used because a single projection flattens three-dimensional anatomy, so two perpendicular views allow localization of lesions, fractures, or foreign bodies in three planes, reveal abnormalities hidden by overlapping structures, assess alignment and depth, and improve diagnostic sensitivity for effusions, consolidation, and spinal or chest pathology. Combining views reduces misinterpretation and guides management.