Purpose: As patella height can affect the outcome of total knee arthroplasty (TKA) in a number of ways, this study aimed to investigate whether factors such as region, sex and age play a role in causing differences in patella height.

Methods: Between the 1st of March and the 31st of December 2022, 2000 patients from 7 different countries (Turkey, Saudi Arabia, Germany, Austria, Italy, Spain, and the United Kingdom) awaiting elective TKA were enrolled in this study. Lateral radiographs of the knee with the femoral condyles fully overlapped were used to measure the Insall-Salvati index. The patella height measurements were then correlated with age, sex and region to see if there were any patterns of distribution.

Results: From ten different hospitals across seven countries, 2,000 patients were collected. Approximately, 50% of the groups were female and 50% were male with a median age at surgery of 59 years (± 20 years). There were no significant differences in patella position based on age, region or sex between the different study populations, although there were significant differences between patients from different countries.

Conclusion: Patella height showed significant variability within our patient cohort, even between different populations within the same country of origin. However, it should be noted that age, sex and country of origin do not appear to influence patella height in the preoperative planning of knee surgery.