Low Back Pain in Knee Osteoarthritis Associated With Greater Fall Risk

Compared with patients with osteoarthritis (OA) without low back pain, patients with knee OA with low back pain may be at greater risk for recurrent falls, according to study results published in Arthritis Care & Research.

The study included data of patients with knee OA (Kellgren and Lawrence [K&L] grade ≥1) who completed questionnaires for low back pain and falls occurring in the previous 12 months. Researchers performed binary and ordinal logistic regression to assess the relationship between low back pain or moderate to severe low back pain (numeric rating scale score, ≥4 points) and any fall (≥1 fall) or recurrent falls (≥2 falls) after adjusting for age, sex, K&L grade, knee pain severity, and quadriceps strength. They also performed sensitivity analyses, excluding data of patients with sciatica, nonchronic low back pain, K&L grade 1, and those receiving pain medications.

Of the 189 patients (aged 61-90 years; 78.3% women), 101 (53.4%) had low back pain and 41 (21.6%) reported experiencing falls in the past 12 months. Among patients who had low back pain, 45 patients (44.6%) had moderate to severe low back pain, and 94 had chronic (>3 months) low back pain.

Compared with patients without low back pain, patients with moderate to severe low back pain had a significantly higher prevalence of falls (chi-square test, P =.007). Patients with any low back pain (n=101) and with moderate to severe low back pain (n = 45) had 2.7 (P =.004) and 3.7 (P =.007) times higher odds of experiencing recurrent falls, respectively.

There was a strong correlation between moderate to severe low back pain and the occurrence of recurrent falls in a sensitivity analysis.

Limitations included the study’s cross-sectional design, a lack of information on pain in other joints, and possible recall bias.

“It is necessary to determine the causality and ascertain the effectiveness of therapeutic interventions for [low back pain] for the prevention of falls in people with knee OA,” the researchers noted.

Reference

Iijima H, Shimoura K, Aoyama T, Takahashi M. Low back pain as a risk factor for recurrent falls in people with knee osteoarthritis [published online January 7, 2020]. Arthritis Care Res. doi:10.1002/acr.24136