Turnover rates in human bone and tissue: A “live” ¹⁴C study

Bone and tissue fractions, obtained in 2017 following hip replacement surgery on a healthy Caucasian male, born in 1944, reflect in their ¹⁴C concentrations the integrated effect of the lifetime metabolic uptake and replacement of atmospheric bomb ¹⁴C at different tissue-specific turnover rates. The ¹⁴C content of hair and nails reflects recent carbon uptake. The ¹⁴C values in healthy cartilage and bone collagen/apatite correspond to those of the “local” atmosphere during the 2005–2009 Northern Hemisphere growing seasons, while those from damaged areas of the femur head correspond to the atmosphere in 2013–2014. A simple bone growth and regeneration model used in combination with the NH atmospheric ¹⁴C concentrations indicates remodelling rates around 9% per year in the healthy bone and a doubling to tripling in the damaged area depending on the model chosen. The differences in ¹⁴C concentration observed in the fractions provide both a caveat for sample selection for the ¹⁴C dating of archaeological bones and an indication of its potential in forensics and as a diagnostic tool for turnover rates in medical studies.