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
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
|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.