Examining bone surfaces across puberty: a 20-month pQCT trial

Area of Science:

• Orthopedics
• Pediatric Endocrinology
• Bone Biology

Background:

• Sex differences in bone size emerge during puberty.
• Previous studies suggested differing bone growth patterns (periosteal vs. endosteal apposition) between sexes.
• This study aimed to prospectively investigate sex-specific cortical bone changes using advanced imaging.

Purpose of the Study:

• To prospectively evaluate sex-specific changes in cortical bone area at the tibial midshaft during puberty.
• To compare periosteal and endosteal bone apposition/resorption patterns between boys and girls.
• To determine if relative cortical bone area increase differs between sexes.

Main Methods:

• Prospective follow-up study using peripheral quantitative computed tomography (pQCT).
• Assessed tibial midshaft in 68 girls and 60 boys across early, peri-, and postpuberty over 20 months.
• Measured total bone area (ToA), cortical area (CoA), marrow cavity area (CavA), and CoA/ToA ratio.

Main Results:

• No baseline sex differences in total or cortical bone area.
• Boys exhibited a ~10% greater increase in ToA and CoA compared to girls.
• The relative increase in cortical area (CoA/ToA) was similar between sexes, with periosteal apposition exceeding endosteal resorption in both.

Conclusions:

• Both sexes exhibit similar patterns of cortical bone change, dominated by periosteal apposition.
• Boys show a greater absolute increase in tibial bone size due to larger dimensional changes.
• Findings do not support endosteal apposition in postmenarchal girls and highlight similar relative cortical area expansion between sexes.