Michael Kleerekoper, MD, MACE, has joined the faculty at the University of Toledo Medical School where he is Professor in the Department of Internal Medicine and section chief of the Endocrinology Division. The author of numerous journal studies, Dr. Kleerekoper serves on the editorial boards for Endocrine Today, Endocrine Practice, Journal of Clinical Densitometry, Journal of Women's Health, Osteoporosis International and Calcified Tissue International. Dr. Kleerekoper is also a founding board member of the newly formed Academy of Women’s Health.

High bone mass

Jennifer's bone density report stated that lumbar spine bone mineral density was + 3.2 and that bone density was "normal". Each vertebra, L1-L4, had a BMD T-score greater than +2.0. To report this as "normal" was clearly wrong, but I have become so used to misread reports from this center that nothing surprises me any more. Hopefully, some day, these rogue "Osteoporosis Centers" will be recognized as such. But I am not holding my breath.

There are many circumstances where BMD might indeed be greater than +2.0, either at the spine or proximal femur, and possibly the forearm, but I cannot recall offhand a high forearm BMD. Each occurrence requires correct reporting with a follow-up imaging study to ascertain the reason for the high bone density.

In the lumbar spine, degenerative disc disease is common and will occasionally result in such high values, as was the case in my patient. Paget's disease affecting the spine and/or proximal femur is often associated with high bone mass and that diagnosis might be made on careful review of the BMD images. Paget's disease in the spine does not often involve contiguous vertebrae such that an affected vertebra will be denser and larger than the others. Adjacent vertebrae not affected by Paget's would not have high BMD values. Paget's affecting the proximal femur is usually characterized by an unusual shape (bending) or coarse architecture and there may also be changes in the pelvic brim visible in some DXA studies. Osteoblastic metastases are also common in the spine but involvement of four contiguous vertebrae is not common.

Any T-score greater than +2.0 at any skeletal site requires careful review of the original DXA scan and, if confirmed, appropriate imaging!!

"Rugger jersey"1 spine (see figures below) is seen in a variety of genetic skeletal disorders collectively grouped as osteosclerosis 2 and also in some patients with advanced renal osteodystrophy. In most of these cases, the diagnosis is well established before any bone mineral testing is considered. The genetics of inherited disorders with high bone mass is being unraveled3.

The two citations in PubMed are worth reading should you encounter a patient with a high BMD that cannot be accounted for by sloppy technology.

For more information:

Radiological features of female patient CII-2 at age 45 years.
Figure A: Lumbar-spine standard radiograph showing thickened and sclerotic vertebral end plates. This feature, usually named "Rugger-Jersey spine," is characteristic of ADO type II. Figure B: Pelvic-front standard radiograph with bone-within-bone sign-usually consisting of concentric bands of sclerosis in round and flat bones, especially in the iliac wings.