RADIOGRAPHIC EVALUATION OF AGE AND GENDER RELATED CORTICAL BONE THINNING USING THE METACARPAL INDEX METHOD: A LAGOS BASED POPULATION STUDY

Background: Cortical bone thickness decreases with age and may differ between genders. The metacarpal index (MCI) is a reliable measure for assessing cortical bone thinning. Purpose: To evaluate age- and gender-related cortical bone thinning using the metacarpal index method. Materials and Methods: A retrospective study was conducted using 850 dorsi-plantar radiographs of the left hand (436 males, 414 females) performed from 2003–2005. Cortical width of the second metacarpal and shaft was measured to calculate the MCI. Values were compared across different age ranges and between sexes. Results: The study showed a gradual increase in MCI for both sexes from 20–40 years, peaking at 57.4 ± 2 for males and 52.8 ± 0.2 for females at 40 years. A linear decrease in MCI was observed after the fifth decade. Males exhibited higher MCI values than females at all ages, with mean values of 53.3 ± 3.2 and 46.21 ± 3.9, respectively. Cortical thinning was more rapid in females than in males. Conclusion: Cortical bone thickness, as measured by MCI, increases until mid-adulthood and declines thereafter, with females showing a faster rate of cortical thinning compared to males.