PMC5788106_01
Radiographic patellar height indices, each measured as a / b. (A) Caton-Deschamps ratio, with line a demonstrating the distance between the distal end of the patellar articular surface to the anterosuperior angle of the tibia and line b demonstrating the length of the articular surface of the patella. (B) Blackburne-Peel ratio, with line a being perpendicular to the tibial plateau line and line b measuring the length of the articular surface of the patella. (C) Insall-Salvati ratio, with line a representing the length of the patellar tendon and line b demonstrating the maximum length of the patella.
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PMC5788106_01_10.1177_2325967117751659-fig1.jpg
fig1-2325967117751659
Two authors (J.M.W. and R.A.C.:an orthopedic sports fellow and a chief resident, respectively) calculated these ratios to ensure interrater reliability (Figure 1).