Influence of osteophytic size on bone mineral density measured by dual X-ray absorptiometry.
OBJECTIVE
To quantify the relationship between individual osteophytic size and measured bone mineral density (BMD) of the lumbar spine by dual x-ray absorptiometry (DXA). Further, to evaluate the possible consequences of this relationship for the management of DXA measurements in postmenopausal patients.


METHODS
In 142 postmenopausal women (mean age 61.8 +/- 8.9 years), plain radiographs of the lumbar spine were evaluated and graded according to evidence and size of osteophytes. The BMD (g/cm2) and Z-score (deviation of BMD from an age-matched population, %) of each vertebral body was determined by DXA. The effects of the individual osteophytic size on BMD measurements were analyzed by using analysis of variance followed by a multiple test procedure.


RESULTS
The presence of osteophytes resulted in a significant increase in BMD of L1 through L4. The increase in relation to an osteophytic size of about 10 mm was: in L1 5.7%, in L2 6.8%, in L3 4.4% and in L4 3.5%. Increases were significantly higher for an osteophytic size of 10-20 mm (L1 23.1%, L2 13.0%, L3 13.4%, and L4 16.3%) and of > 20 mm (L1 21.4%, L2 22.4%, L3 21.1% and L4 4.1%).


CONCLUSIONS
Our results indicate a nonlinear increase of measured BMD with increasing osteophytic size. These effects should be considered in routine examination and patient management.
Rand
T
T
Department of Radiology, University of Vienna, Ludwig Boltzmann Institute for Radiologic Tumor Diagnosis, Austria.
Schneider
B
B
Grampp
S
S
Wunderbaldinger
P
P
Migsits
H
H
Imhof
H
H
D015502:Absorptiometry, Photon / Q000379:methods*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000473:pathology; D008875:Middle Aged; D017698:Postmenopause; D013128:Spinal Osteophytosis / Q000000981:diagnostic imaging* / Q000473:pathology