The AP (anteroposterior) knee view is an X‑ray taken with the X‑ray beam entering the front and exiting the back of the knee. The patient is supine or standing with the leg extended and slightly internally rotated to align femoral condyles. The beam is centered at the joint line. It demonstrates distal femur, proximal tibia, joint space, alignment, fractures and degenerative changes; a weight‑bearing AP assesses osteoarthritis.

"AP leg" stands for anteroposterior leg radiograph. It is an X‑ray taken front-to-back, usually imaging the tibia and fibula (knee-to-ankle or hip-to-ankle) to assess fractures, bone alignment, joint spaces and deformities. It is often performed with a lateral view for complete evaluation. The patient lies supine or stands with the limb positioned flat while the beam is centered on the area of interest.

A standard knee X‑ray typically includes three views: anteroposterior (AP) — weight‑bearing when assessing joint space and alignment; lateral — shows patellofemoral joint, joint effusion, and sagittal alignment; and axial (skyline/sunrise or Merchant) — specialized patellar view to evaluate the patellofemoral joint and cartilage surface. Occasionally oblique views are added for suspected fractures or to further delineate deformity.

AP (anteroposterior) and Lat (lateral) describe X‑ray beam direction. AP projects front-to-back—commonly used for supine or portable films; it may magnify mediastinal and cardiac contours. Lateral projects side-to-side, offering a profile view to localize abnormalities, assess depth, and detect air‑fluid levels. Combined AP and lateral views improve lesion localization and diagnostic confidence.

Anterior patellar dislocation is when the kneecap (patella) is forced out of its normal position, usually after a twist or direct blow. It causes sudden pain, swelling, inability to straighten the knee and often a visible deformity. Initial treatment includes realignment, immobilization, pain relief and physiotherapy; recurrent or severe cases may require imaging and surgical repair to stabilize the patella.

An AP (anteroposterior) view means the X‑ray beam travels from front to back. To identify it, check for an “AP” marker or a supine/portable exam note. Clues include scapulae projecting over the lung fields (not retracted laterally), clavicles appearing more horizontal/medially displaced, apparent heart magnification, and presence of external lines or poor inspiratory effort suggesting a portable AP technique.