Background/Purpose: Relative local knee periarticular bone mineral density (paBMD) as measured by dual x-ray absorptiometry (DXA) has been associated with features of radiographic knee osteoarthritis (OA).   We postulated that this measure is associated with knee pain and measures of quality of life. To address this question, we evaluated the association of paBMD with pain and quality of life. 

Methods: We performed a cross-sectional study of a subgroup of the incidence subcohort of the Osteoarthritis Initiative (OAI) who had knee DXA scans from the 72-month visit.  We evaluated the right knee using identical GE Lunar Prodigy scanners, generating knee medial:lateral paBMD ratios focused on the tibial plateau.  Frequency of knee pain was assessed using the 72-month visit question, “In the past 12 months, have you had pain, aching or stiffness in or around your knee on most days for at least one month?”  The Knee injury and Osteoarthritis Outcome Score quality of life (QOL) assessments were also evaluated as outcomes – each item was dichotomized with a high score considered a symptomatic outcome. We performed logistic regression with a predictor of medial:lateral paBMD groups based on biologic cut points (1) low paBMD Ratio group with scores < 1.02, (2) neutral group (referent) with scores ≥ 1.02 and < 1.17, (3) high group with scores ≥ 1.17 and < 1.24 and (4) very high group with scores ≥ 1.24.  Analyses were adjusted for age, sex, and BMI.

Results: 985 participants, 51% female, were included with a mean age of 65.4 (8.4) years and BMI of 28.1 (4.9) kg/m².  The very high paBMD Ratio group had more pain compared to the neutral group (Table 1). 

Conclusion: Relative local paBMD is associated with contemporaneous knee pain and some quality of life assessments.  These findings may suggest that changes within the local bone have a clinically relevant influence on knee pain.  Modification of the medial:lateral paBMD Ratio may improve knee pain and assist in identifying new targets of therapy.