The value of the Merchant view
This is a highly valuable view, but the need for the special cassette means that it is often omitted. The Merchant view gives information about congruence with the underlying groove, patellar tilt and lateral patellar displacement.
Discrepancies of Patellofemoral Indices between Supine and Standing Merchant Views. KimT-H, MD, Lee J-S and Oh K-J. Knee Surg Relat Res. 2014 Mar; 26(1): 20–26.