The microscopic determination of age in human bone

Abstract

The microscopic age changes that occur in human cortical bone were measured by counting the number of osteones, osteon fragments and non‐Haversian canals, and estimating the percentage of lamellar bone in four selected 100 power fields in the outer third of the cortex in ground sections from the mid‐shaft of the femur, tibia and fibula. Age graphs were derived from 126 specimens covering the age range from birth through 95 years. The best correlation with age by regression analysis was found in the osteon fragment number in the fibula (ρ = 9.74). The use of the regression formula for this factor permits the age to be estimated within ± ten years of the actual age 95% of the time.An alternative method utilizes a specially devised profile chart to estimate age from the age change graphs. When this method was checked on 56 additional specimens, 87.3% of the estimates were within ± five years of the actual age, and all estimates were within ± ten years.It was concluded that there are measurable microscopic age changes in the cortex of the major long bones of the leg that can be used to estimate the age of an individual with known accuracy over the entire range from birth to 95 years. This method can be applied to fragmented and incomplete skeletons as well as eroded archeologic skeletons, since only the mid‐shafts of leg bones are used.

Super‐osteons (remodeling clusters) in the cortex of the femoral shaft: Influence of age and gender

“…Thus the estimated number of giant canals probably includes some that we would have defined as being too small to be classified as giants. Finally, the relatively few numbers of subjects of each gender within each age group may have resulted in a lack of statistical power for the estimation of parameters such as canal density that in a number of previous studies has been shown to have an age-related pattern (Atkinson, 1965;Currey, 1964;Kerley, 1965Kerley, , 1969). In the current study, this parameter was not influenced significantly by age.…”

Alkaline earth metabolism in adult man

“…Finally, we realized that Kerley's counts of the number of osteons in the outer third of the midshafts of the long bones of 126 normal men as a function of age (25) could be fitted quite accurately by the same single exponential with a A-value of 2-3 %/year. At this point, we decided to set A, the model's rate of compact bone turnover, at 2.5 %/year and to see whether consistent fits could be obtained between all the other parameters and their supporting data.…”

“…(a) Bone Number of osteons versus age in compact bone (Kerley, 1965). (2s) Tetracycline data for rates of bone formation (Frost, 1969).…”

“…Detailed calculations using realistic rates of remodeling and measurements for diffuse up-take versus local bone age (section D7b), show that the condition of approximate, kinetic homeostasis described above should actually occur for adults more than about 25 New bone refers to bone which forms or mineralizes after the time of radioisotope injection. Although most of the activity in new bone can be described as hotspot activity, it also includes the activity in bone formed long after injection which may have an activity per gram calcium comparable to or less than that in old bone.…”

“…The result is fr = 4 fc (1 --fi)/fia. (25) fr is therefore not an independent parameter of the model but follows directly from the values for/3, a, and fo…”