The skyline view of the patella is an axial (sunrise) radiograph taken with the knee flexed and the X-ray beam tangential to the patella. It depicts the patellofemoral joint, patellar facets and femoral trochlea to assess fractures, alignment, subluxation, tilt, arthritis and chondral lesions. It complements AP and lateral knee images for patellar evaluation.

Skyline view (axial or sunrise view) is an X‑ray projection of the patella and patellofemoral joint obtained with the knee flexed and the X‑ray beam directed tangentially across the patella. It visualizes the patellar articular surface, sulcus, joint space, fractures, osteochondral lesions, and alignment—useful for suspected patellar fracture, dislocation, chondral disease, and patellofemoral arthritis.

A knee lateral view X‑ray is a side‑profile radiograph of the knee that images the femur, tibia, fibula and patella in profile. It helps detect fractures, dislocations, joint space narrowing, osteoarthritis, and fluid (effusion). Typically obtained with the knee slightly flexed so bony alignment and patellar position are clear. It’s quick, outpatient, and uses low‑dose ionising radiation.

Have the patient sit or lie with the knee flexed about 90° (or as tolerated). Place the detector under the distal femur with the patella centered. Direct the X‑ray beam tangentially to the patella at roughly 15–30° cephalad (protocol dependent) so it skims the patellofemoral joint. Collimate to the knee, ask the patient to remain still, use shielding and correct exposure settings.

The best time to view a skyline is during golden hour, about 30 to 60 minutes after sunrise or before sunset, when warm angled light enhances color and contrast. Blue hour (twilight), roughly 10 to 20 minutes after sunset or before sunrise, offers deep skies with illuminated buildings. Aim for clear, low-humidity conditions and an elevated, unobstructed vantage point.

Sunrise (Settegast) view is a tangential patellar radiograph taken with the knee flexed about 90° (prone or seated) and beam angled to profile the patellofemoral joint—good for patellar facets and vertical alignment. Skyline (axial/Merchant variants) is a general axial patellar view usually with 20–45° flexion (supine/sitting), useful for assessing patellar tilt, subluxation and cartilage wear.