When between-patient confounding is minimized, there is a strong association between medial knee load and increased knee pain while walking in patients with osteoarthritis, according to a study published in Arthritis Care & Research.
The current study sought to examine the association between the knee adduction moment and increased knee pain during walking in patients with knee osteoarthritis. The 265 participants included in the study had osteoarthritis located chiefly in the medial tibiofemoral compartment with varus or neutral alignment. Participants rated knee pain before and after a 6-minute walk using a 0 to 10 scale, and then walked in bare feet across a level, 10-meter floor for 3-dimensional gait analysis.
The peak knee adduction impulse and knee adduction moment (used as medial knee loading proxies) were associated with increased levels of pain (odds ratio [OR], 6.62; 95% CI, 3.46-12.7 and OR, 2.43; 95% CI, 1.77-3.33, respectively). Levels of increased pain remained significant even after data were controlled for radiographic disease severity. When levels of medial knee loading were split into quartiles, according to knee adduction impulse and knee adduction moment, participants in the highest knee loading quartile had 9.0 (95% CI, 4.0-20.1) and 4.7 (95% CI, 2.3-9.5) greater odds of suffering increased pain while walking, respectively, than participants in the lowest knee loading quartile.
Study investigators conclude, “these findings suggest that when between-patient confounding is minimized, there is a strong association between medial knee load and increased knee pain during walking.”
Birmingham TB, Marriott KA, Leitch KM, et al. Association between knee load and pain: Within-patient, between-knees, case-control study in patients with knee osteoarthritis [published online July 13, 2018]. Arthritis Care Res (Hoboken). doi:10.1002/acr.23704