Growth of the second metacarpal (MC) was evaluated during female adolescence in 110 Turkish girls who were followed longitudinally starting from 8.5 to 11 years until a Greulich and Pyle skeletal age (SA) greater than or equal to 17 years was reached. Stature (St), weight (Wt), stage of secondary sexual development (SSD), length (L), and medullary (M) and outer diameters (D) of MC were measured. Total cortical thickness (C) of MC was derived as the difference between D and M. Yearly rates of growth in L, D, C, and St were calculated for each 6 months from the smoothed data. Peak length (PLV), peak D (PDV), and peak C (PCV) velocities and the ages at reaching these peaks were determined. L at fusion was 62.4 +/- 3.0 mm and correlated significantly with adult stature (AdSt). PLV was 4.09 +/- 0.60 mm/yr at a mean age of 12.28 +/- 0.90 years and it correlated best with PHV (r = 0.52), then with L at fusion and AdSt, but not with ages at PLV, PHV, PDV, fusion, and onset of SSD. PLV occurred synchronously with PDV, 0.1 years after PHV, 0.9 years after onset of the breast bud, 0.4 years after onset of axillary hair, and 1.1 years before menarche. Age at PLV correlated best with age at PHV, and in decreasing order with ages at fusion, menarche, PDV, and onset of SSD, but not with PLV, PDV, PHV, L at fusion, and AdSt. The most important single factor determining MC L was St (R = 0.77). Multifactorial analysis showed that in conjunction with St, D and C are contributory determinants of L, while SA is not. MC D was primarily determined by L. In conjunction with L, C and chronological age (CA) contributed positively and SA negatively. Velocity of C reached its peak at 13.04 +/- 1.20 years, 0.72 and 0.76 years after PLV and PDV, respectively. After 14 years, C continued to increase significantly, while growth increments in D and L were greatly reduced. This was realized by a significant reduction in M, which indicates that there is endosteal deposition of bone. Increase in C was significantly associated with increasing stages of SSD and inversely with M. Multifactorial analysis, however, showed that SSD is not an independent factor and that C is determined primarily by SA, and then inversely by M and directly by L. Once these factors are known, other factors, such as SSD, St, and Wt, lose their significance. (C) 1997 Wiley-Liss, Inc.