Magan, AMicklesfield, L KNyati, L HNorris, S APettifor, J M2024-09-012024-09-012018-11-13Magan A, Micklesfield LK, Nyati LH, Norris SA, Pettifor JM. A longitudinal comparison of appendicular bone growth and markers of strength through adolescence in a South African cohort using radiogrammetry and pQCT. Osteoporos Int. 2019 Feb;30(2):451-460. doi: 10.1007/s00198-018-4761-9.https://doi.org/10.1007/s00198-018-4761-9https://pubmed.ncbi.nlm.nih.gov/30426171/https://hdl.handle.net/11288/597384To compare growth patterns and strength of weight- and non-weight-bearing bones longitudinally. Irrespective of sex and ethnicity, metacarpal growth was similar to that of the non-weight-bearing radius but differed from that of the weight-bearing tibia. Weight- and non-weight-bearing bones have different growth and strength patterns. Introduction: Functional loading modulates bone size and strength. Methods: To compare growth patterns and strength of weight- and non-weight-bearing bones longitudinally, we performed manual radiogrammetry of the second metacarpal on hand-wrist radiographs and measured peripheral quantitative computed tomography images of the radius (65%) and tibia (38% and 65%), annually on 372 black and 152 white South African participants (ages 12-20 years). We aligned participants by age from peak metacarpal length velocity. We assessed bone width (BW, mm); cortical thickness (CT, mm); medullary width (MW, mm); stress-strain index (SSI, mm3); and muscle cross-sectional area (MCSA, mm2). Results: From 12 to 20 years, the associations between metacarpal measures (BW, CT and SSI) and MCSA at the radius (males R2 = 0.33-0.45; females R2 = 0.12-0.20) were stronger than the tibia (males R2 = 0.01-0.11; females R2 = 0.007-0.04). In all groups, radial BW, CT and MW accrual rates were similar to those of the metacarpal, except in white females who had lower radial CT (0.04 mm/year) and greater radial MW (0.06 mm/year) accrual. In all groups, except for CT in white males, tibial BW and CT accrual rates were greater than at the metacarpal. Tibial MW (0.29-0.35 mm/year) increased significantly relative to metacarpal MW (- 0.07 to 0.06 mm/year) in males only. In all groups, except white females, SSI increased in each bone.enFunctional loadingGrowth patternsMuscleRadiogrammetryStress-strain indexpQCTArticle