Ultrasound reference values for trochlear cartilage in healthy black African subjects: a study of a cohort of 506 participants

Assessing the thickness of the trochlear cartilage is essential for the early diagnosis of knee joint disorders, with ultrasound serving as an accessible alternative to MRI. However, morphometric data specific to sub-Saharan African populations are virtually nonexistent in the literature, unlike those for Caucasian or Asian populations. This study aimed to establish ultrasound reference values in healthy adults of Black African descent and to identify factors contributing to variation. Cross-sectional study conducted at Bogodogo University Hospital (Burkina Faso) on 506 healthy participants (1,012 knees) aged 18 to 45 years. Thickness was measured by a single radiologist using an ultrasound scanner with a high-frequency linear probe (8-15 MHz) at the medial condyle (MC), lateral condyle (LC), and intercondylar zone (ZIC). Multiple linear regression was used to analyze the factors associated with variations in thickness. The study population consisted of 408 men (80.63%) and 98 women (19.37%) with a mean age of 24.36 years [95% CI: 24.06–24.66], ranging from 19 to 45 years. The mean thickness was 2.36 mm [95% CI: 2.33–2.39] at the MC, 2.38 mm [95% CI: 2.35–2.41] at the LC, and 2.60 mm [95% CI: 2.57–2.74] at the ZIC. Bivariate analysis showed significantly thicker cartilage in men (p = 0.001). After multivariate adjustment, gender and weight remained positively associated with thickness (p < 0.001), while BMI showed a negative association. Age was no longer significantly associated in the final model. This study provides the first ultrasound reference values for trochlear cartilage in sub-Saharan Africa, highlighting the influence of gender and body weight on its thickness. These data constitute an essential diagnostic foundation for the early detection of chondropathies in our setting. Future research correlating these measurements with MRI findings will help consolidate these reference values and refine the monitoring of early-stage osteoarthritis.