HLA-DRB1 and DQB1 genes in anticentromere antibody positive patients with SSc and primary biliary cirrhosis

Periarticular bone mineral density at the knee jointRecently, dual energy x ray absorptiometry (DXA) was presented by Murphy et al as a new method for assessing periarticular bone mineral density (BMD) at the knee joint. 1 Precision errors for BMD measured at the patella, femur, and tibia were reported for 14 subjects.The paper highlights the emerging importance of measurement of radiological data and attention to regional density characteristics in bone and joint diseases.Subchondral bone mineral density of the proximal tibia has previously been assessed by dual photon absorptiometry (DPA)-the precursor of DXA.Relations between subchondral BMD of the proximal tibia and age, height, weight, and BMD of the lumbar spine and femoral neck were examined by Bohr and Schaadt. 2 Petersen et al presented subchondral BMD values for a large number of healthy subjects and for patients with various orthopaedic conditions. 3Bohr and Lund and Petersen et al examined changes in BMD at the proximal tibia after knee arthroplasty. 4 5Petersen et al examined subchondral BMD after meniscectomy, 6 and Madsen et al reported data for subchondral BMD measured in several subregions of the proximal tibia in healthy subjects and in subjects with osteoarthritis of the knee. 7Moreover, Petersen et al studied relations between bone strength and BMD assessed by DPA and DXA in the proximal tibia. 8Other related studies could be mentioned.Unfortunately, none of these studies was referred to by Murphy et al.