X Ray Left Patella Skyline View

The skyline (axial or tangential) view of the patella is a radiographic projection obtained with the knee flexed and the X-ray beam directed tangentially to the patella. It visualizes the patellar articular surface and trochlear groove, permitting assessment of patellofemoral alignment, subluxation, osteochondral lesions, cartilage wear, and undisplaced fractures. Variants include the sunrise and Merchant views.

The skyline view (axial/tangential patellar view) is an X‑ray projection of the patella and femoral trochlea taken with the knee flexed. It highlights patellofemoral alignment, articular surfaces, and fractures or osteochondral defects that may be missed on standard AP/lateral films. It’s commonly used to evaluate patellar subluxation, chondral injury, and arthritis.

The skyline view (patellar skyline or axial/tangential view) is an X‑ray projection of the patella and patellofemoral joint taken with the knee flexed and the beam tangential to the patella. It shows the patellar articular surface, facets, cartilage space and relationship to the femoral trochlea, helping detect fractures, maltracking, tilt, subluxation, or degenerative changes.

Position the patient seated or supine with the knee flexed about 30–45° so the patella is tangential to the film. Center the detector at the patellofemoral joint. Direct the X‑ray beam tangentially (typically 15–30° cephalad, adjusted for flexion) to visualize the patella and trochlea. Use shielding, ask the patient to relax, and adjust exposure for optimal joint detail.

The skyline (sunrise) view is an axial X‑ray of the patella taken with the knee flexed to visualize the patellofemoral joint. It’s used to detect patellar fractures, osteochondral lesions, dislocation or subluxation, joint‑space narrowing, osteophytes, loose bodies and chondral wear. It also helps assess patellar tracking and alignment for diagnosis and pre- or postoperative planning.

The best time is during golden hour—shortly after sunrise or before sunset—when low-angle light enhances colors and contrast. The blue hour (twilight) also yields dramatic skies and city lights. For clarity, aim for early morning after air clears or on a cool, low-humidity day; avoid midday glare and high pollution or haze. Choose a high vantage point with unobstructed views.