The Merchant view is a special X-ray view of the knee that shows clearly the position of the patella in the underlying groove of the trochlea with the muscles at rest.

Page updated February 2024 by Dr Sheila Strover (Clinical Editor)

merchant viewSupine non-weight-bearing arrangement. The view can also be done in a standing (weight-bearing) position, which will give more accurate information about malalignment.
trochlear grooveNormally the patella lies centrally within the groove.


What is the value of the Merchant view of the knee?

The 45 degree angle to the cassette gives information about -

  • how congruent is the back of the patella with the underlying groove
  • whether there is any patellar tilt
  • if the patella is abnormally displaced to one side

It is a highly valuable view, but the need for the special cassette means that it is often omitted in routine knee X-rays.

This x-ray view is also commonly referred to as the skyline view or the sunrise view.


Back to top


How does a Merchant view compare to a weight-bearing X-ray?

In the Merchant view the patient lies at rest and any distortion of the anatomy that might be contributed from bearing weight is not appreciated. So evaluation of any closure of the joint space from osteoarthritis or meniscal degeneration would need a weight-bearing view, such as the Rosenberg view.

Back to top


Can the TT-TG distance be measured on a Merchant view?

In a large number of cases a Merchant view will allow measurement of the TT-TG distance, or how out of alignment the patellar tendon is, and this will avoid the need for an MRI scan.

  • Quote from peer-reviewed paper:

    "The tibial tubercle could be identified on Merchant radiograph in...81.7%....Merchant TT-TG strongly correlates with MRI TT-TG but measured 5-8 mm smaller...."

    Citation: Bernholt D, Lamplot JD, Eutsler E, Nepple JJ. Utility of Merchant View Radiographs for Assessment of TT-TG: A Comparison to MRI. Orthop J Sports Med. 2018 Jul 27;6(7 suppl4):2325967118S00075. doi: 10.1177/2325967118S00075. PMCID: PMC6083762.

Back to top


skyline view
sunrise view
sunrise x-ray

Dr Sheila Strover (Editor)
BSc (Hons), MB BCh, MBA

See biography...