Femoral Cartilage Morphology in Collegiate Archery, Badminton, and Taekwondo Athletes and Nonathletes: A 12-month Prospective Cohort Study.

BACKGROUND: Monitoring femoral cartilage morphology in athletic populations may aid early detection of cartilage degeneration and long-term sport-specific adaptations. HYPOTHESIS: Femoral cartilage morphology would differ depending on the type of sport, with badminton and Taekwondo athletes expected to show greater reductions than archery athletes and nonathletes at a 12-month follow-up. STUDY DESIGN: Prospective cohort. LEVEL OF EVIDENCE: Level 2. METHODS: Eighty athletes (29 archery; 23 badminton; 28 Taekwondo) and 29 nonathletes completed ultrasonographic assessment of bilateral femoral cartilage cross-sectional area (CSA) and thickness (lateral condyle, intercondylar, and medial condyle) at baseline (1st year) and at 12-month follow-up (2nd year). Data were analyzed using repeated-measures linear mixed models adjusting for sex, age, and body mass index. Post-hoc pairwise comparisons used the Tukey method, and Cohen's d effect sizes were calculated. RESULTS: Significant group × time interactions (F3,315 = 2.66-14.27; P < 0.05) were observed for femoral cartilage CSA and lateral and medial condyle thickness; badminton athletes consistently exhibited greater CSA and thickness than archery athletes (d = 0.87-1.05) and nonathletes (P ≤ 0.002; d = 1.20-1.78), while Taekwondo athletes showed greater CSA and thickness than nonathletes (P ≤ 0.001; d = 0.83-1.46). Within-group decreases from the 1st year to 2nd year were observed in CSA for Taekwondo athletes (P = 0.01; d = 0.56), lateral condyle thickness for badminton and Taekwondo athletes (P ≤ 0.03; d = 0.61-0.69), and medial condyle thickness across all athlete groups (P ≤ 0.002; d = 0.57-1.02). No significant interactions were observed for intercondylar thickness, but group and time main effects were present; badminton athletes displayed the greatest thickness (P < 0.001; d = 0.83-1.20), and thickness decreased over time (P < 0.001; d = 0.40). CONCLUSION: Collegiate athletes demonstrate sport-specific adaptations and time-dependent changes in femoral cartilage morphology. Badminton and Taekwondo athletes exhibited greater CSA and thickness than archery athletes and/or nonathletes, with reductions observed after a 12-month follow-up. CLINICAL RELEVANCE: Sport-specific evaluations may help clinicians detect early deviations in cartilage adaptation.