Osteoarthritis in morbidly obese children and adolescents, an age-matched controlled study

Main objective of this study was to investigate the association of pain and early cartilage lesions in morbidly obese children and adolescents.

A total of 57 subjects were included in the study. Morbidly obese patients (n = 39) were subdivided into two groups: Group A: (11 males and 9 females, 14.2 ± 2.7 years) with permanent knee pain; and Group B: (10 males and 9 females, 14.4 ± 2.2 years) without permanent or without any knee pain. Group C (8 males and 10 females, 15.0 ± 2.9 years) included age-matched children and adolescents of normal weight. MRI examinations were performed in all subjects, and an extensive analysis of the images was conducted according to the condition of the cartilage surface and the meniscus. Patients' subjective health was assessed by means of four well-known knee scores (IKDC, KOOS, Tegner/Lysholm, and VAS). Nonparametric Jonckheere-Terpstra test was used to test the trend of the natural order between the three groups.

In 38 of 39 morbidly obese children and adolescents, in at least one region of the knee, a marked cartilage lesion could be shown by MRI. Group A showed significantly (p < 0.001) more cartilage lesions (mean 3.7) compared to Group B (mean 2.8) and Group C (mean 0.8). IKDC, and all the KOOS subunits, showed significantly (p < 0.001, p Bonferroni < 0.001) increasing scores from Group A to B to C, in addition to KOOS symptoms.

Morbid obesity causes early lesions of the knee cartilage, even in young patients. Significantly, more patients with reported pain show more severe damages.