Dual-energy X-ray absorptiometry in osteonecrosis of the femoral head.
Osteonecrosis of the hip classically produces a heterogeneous density in the femoral head, although the bone marrow ischemia extends down to the femoral neck and trochanters. Also, bone insufficiency fractures due to diffuse bone loss have been implicated in the genesis of osteonecrosis.


OBJECTIVE
To use dual-energy X-ray absorptiometry to quantify the bone changes produced by osteonecrosis of the hip and to compare bone mineral density values in patients with osteonecrosis of the hip and in controls.


METHODS
Bone mineral density was measured at the femoral neck (total femoral neck, Ward's triangle, and trochanter), femoral head and lumbar spine using dual-energy X-ray absorptiometry (DPX, L Lunar) in 22 patients with osteonecrosis of the hip and in 22 age- and sex-matched controls.


RESULTS
In the patients with osteonecrosis, bone mineral density on the affected side was higher than on the opposite side at the femoral head (+18%), femoral neck (+7%), and Ward's triangle (+6%) and lower at the trochanter (-4%). These differences were most marked at the more advanced end of the osteonecrosis spectrum. As compared to age-specific normative values, the osteonecrosis patients had moderately decreased bone mineral density values at the lumbar spine (-0.53 +/- 1.1 SD or -6 +/- 1.5%) and at the femoral neck on the normal side (-0.9 +/- 1.4 SD or 12 +/- 1.8%). As compared to the controls, bone mineral density was significantly decreased at Ward's triangle (-25%; P: 0.04) and nonsignificantly decreased at the lumbar spine (-4.7%; P: 0.15) and at the femoral neck (-15%; P: 0.09).
Rheumatology Department, Rangueil Teaching Hospital, Toulouse, France.
M
M
Laroche
L
L
Costa
J
J
Bernard
J
J
Puget
A
A
Constantin
A
A
Cantagrel
B
B
Mazières
D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density; D005260:Female; D005270:Femur Head / Q000000981:diagnostic imaging / Q000473:pathology; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000473:pathology; D005598:Fractures, Spontaneous / Q000150:complications / Q000473:pathology; D006620:Hip Fractures / Q000150:complications / Q000473:pathology; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000473:pathology; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies