The Impact of Lumbar Spinal Stenosis, Knee Osteoarthritis, and Loss of Lumbar Lordosis on the Quality of Life: Findings from the Katsuragi Low Back Pain Study

Introduction: Musculoskeletal diseases and spinal malalignment are associated with poorer quality of life (QOL) in the elderly. However, to date, few general population cohort studies have focused on these conditions together. Our objectives were to clarify the associations between musculoskeletal degenerative diseases and/or spinal malalignment with QOL measures in a group of Japanese older adults. Methods: In this cross-sectional study, we analyzed data from 334 individuals recruited from the local population (120 men, 214 women; mean age 62.7 years; range 40-75). Low back pain (LBP) was assessed by questionnaire, and lumbar spinal stenosis (LSS) was diagnosed using a validated lumbar spinal stenosis support tool. Knee osteoarthritis (KOA) was diagnosed by the presence of clinical knee pain plus radiographic KOA. Spinal radiographs were used to assess the degree of lumbar lordosis (LL) and sagittal vertical alignment (SVA). QOL assessment was performed using the Oswestry Disability Index (ODI). A score of 12 was used as a cut-off point for poor QOL. Results: Overall, 107 (32.0%) participants had an ODI > 12 (cases), and the remaining 227 individuals were designated controls. LBP, LSS, KOA, and LL were associated with poorer QOL, both in basic models and models adjusted for age, sex, and BMI. Associations persisted after adjustment for other musculoskeletal outcomes. Conclusions: In a free-living Japanese population, the poor QOL odds are increased by LBP, LSS, KOA, and certain spinal radiographic features, loss of LL, and increased SVA. Poor QOL odds were greatest in those diagnosed with LSS or KOA. From spinal radiographs, decreased LL and increased SVA were also predictors of poor QOL.