Osteoarthritis (OA) patients whose problem is with the knee and who also have pain in other joints could experience greater knee pain, says a new study.
Specifically, pain in the lower back as well as foot pain and elbow pain on the same side as the affected knee were associated with more severe knee pain.
The current study team led by Pradeep Suri, from New England Baptist Hospital used data provided by individuals from the Osteoarthritis Initiative-a multicenter population-based observational cohort study of knee OA.
A subgroup of 1,389 participants, aged 45-79 years who had symptomatic knee OA in at least one knee were included, with patients also asked to identify pain in the lower back, neck, shoulder, elbow, wrist, hand, hip, knee, ankle or foot.
Researchers used the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to measure the level of pain of patients in the study on a scale of 0 to 20 with lower scores representing less pain and stiffness.
Results indicated that 57.4pc of participants reported having pain in their lower back.
They found that low back pain was significantly associated with an increase in the WOMAC knee pain score, with similar associations demonstrated in all other individual joint locations that were studied.
Additionally, researchers determined that having more than one pain location, regardless of the site, was associated with greater WOMAC knee pain score. In participants with four or five pain locations the severity of knee pain was even higher.
"Our findings show that pain in the low back, foot and elbow may be associated with greater knee pain, confirming that symptomatic knee OA rarely occurs in isolation. Future studies are needed to determine whether treatment of pain occurring elsewhere in the body will improve therapy outcomes for knee OA," said Suri.
Full details appear in the journal Arthritis Care and Research.