Relationship between subcutaneous knee fat thickness and chondromalacia patella: magnetic resonance imaging study in Ethiopia

Abstract

The association between chondromalacia patella (CP) and obesity has been increasingly recognized. This study aimed to evaluate the relationship between CP and medial subcutaneous fat thickness (SFT), as magnetic resonance imaging (MRI) -based marker of localized medial knee adiposity. A retrospective review of knee MRI examinations was conducted using a systematically selected sample of 333 cases. The MRI images were analyzed for the presence and severity of CP, and medial SFT was measured. Observer agreement for the measurements was determined through intra- and inter-observer reliability assessment. Among the evaluated knee MRIs, CP was present in 189 cases (56.8%). Observer reliability testing indicated strong agreement. A significant association between SFT and CP was observed in the overall cohort ( p < 0.001) and among male participants ( p = 0.030). In the female subgroup, the association did not reach statistical significance, although a borderline p-value was observed ( p = 0.059).Correlation analysis using Spearman’s method revealed a weak yet statistically significant positive association (ρ = 0.274, p < 0.001). In ordinal logistic regression analysis, age and sex were significant predictors of CP severity, while SFT showed a positive but non-significant association (OR ≈ 1.018, p = 0.088). Subcutaneous fat thickness demonstrated a positive association with CP in the overall cohort and among male participants, whereas the association did not reach statistical significance in female participants. Furthermore, after adjustment for age and sex, the association was no longer statistically significant. These findings should therefore be interpreted with caution.