Normal Reference Values of the Blackburne-Peel Ratio for Measuring Patellar Height in an Indian Population

Abstract

Background Historically, the quadriceps tendon has the largest sesamoid bone of the body, which is known as the patella. Patellar height is one of the important parameters in assessing patellar stability. The patella height has been found to vary in several diseases. As a result, ratios based on a variety of patellar bone indices are used to determine the norms. This study aimed to determine the typical patella height ratio in Indians, who have different sitting and squatting positions as opposed to Caucasians, by applying the Blackburne-Peel ratio to assess patellar height which is an alternative to the conventional Insall-Salvati ratio. Methodology A total of 100 normal lateral knee radiographs from the Indian population were used in this retrospective study. The Blackburne-Peel method (A/B) was used to calculate the ratios. It was calculated as perpendicular length measured from the inferior articular point of the patella to the point perpendicular (A) to the tibial plateau to the length of the articular surface of the patella (B). Results Patella height ratio for men was 0.67 ± 0.01, whereas, for women, it was 0.67 ± 0.02. The ratio did not differ significantly (p > 0.05) from the Western population. Conclusions The normal range of the Blackburne-Peel ratio for the Indian population was established, which can be used as a baseline and can be helpful in establishing patellar height in the Indian population. Similar to previous studies, our study shows that patella height ratios are stable regardless of gender or race and can be used to enhance and restore knee kinematics and functions.