This study - and you can download the full text is "Case Study: Bone Mineral Density of Two Elite Senior Female Powerlifters". The case study tells us that both these women had trained for about 30 years, and that,
"The Z and T [age-matched and compared-to-youth bone mineral density] scores of the 54-year-old mark the largest ever reported in the literature for a Caucasian woman of this age"
and
"approximately 85% of women in the USA .over 50 years suffer from either low BMD or osteoporosis. The 2 women in the study, with an average age of 52, had T scores that were not only well above pathological levels but also far above the average 20- to 29-year-old woman at the peak of her BMD."
The bone may still be delaminating, the study didn't address that. But what's left of it is getting denser the longer you lift.
Notably, the study concludes,
"Several previous investigations that reported resistance training having little to no effect on BMD measured changes during <1 year of training and prescribed loading strategies far lower than the 1 repetition maximums typically performed by competitive lifters like the subjects of this study. This may suggest that duration and intensity prescriptions need to be considerably enlarged for skeletal changes like those seen in this investigation to be observed."
Translation from Cautious Study Speak is: PUT ANOTHER PLATE ON THE BAR.