Varus thrust is a risk factor for incident and worsening knee pain among patients with or at risk for osteoarthritis, according to data published in Arthritis Care & Research.
“As knee symptoms are more indicative of clinical intervention than structural changes, separate inquiry into the relation of varus knee thrust to knee symptoms (ie, pain) is warranted,” Alexandra E. Wink, PhD, of Boston University, and colleagues wrote. “Previous studies have shown a cross-sectional association between varus knee thrust and knee pain. Longitudinal data to confirm the directionality of the relationship between thrust and pain and to describe the effect of thrust on both the onset of new pain and worsening of existing pain are lacking.”
To analyze the association between varus thrust observed during walking and the 2-year incidence and worsening of knee pain, the researchers reviewed data from the Multicenter Osteoarthritis Study (MOST), a prospective, observational cohort trial of knee OA among older Americans who have or are at risk for the condition. Wink and colleagues assessed video recordings of self-paced walking trials from 1,623 MOST participants who contributed 3,204 knees for the study.
Varus thrust is a risk factor for incident and worsening knee pain among patients with or at risk for OA, according to data.
Patients in the MOST study were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire at baseline and at 2 years. Using this data, Wink and colleagues conducted a logistic regression to estimate the likelihood of worsening knee pain, as measured by any increase in WOMAC score, adjusting for age, sex, race, BMI, clinic site, gait speed and static knee alignment.
According to the researchers, varus thrust was demonstrated in 31.5% of all knees. Compared with those without varus thrust, knees with varus thrust had 1.44 times (95% CI, 1.19-1.73) the odds of any — and 1.37 times (95% CI, 1.11-1.69) the odds of clinically important — worsening WOMAC pain. In addition, knees with thrust without baseline WOMAC pain demonstrated 2.01 (95% CI, 1.47-2.74) times the likelihood of incident total pain.
“Our results indicate that varus thrust is a risk factor for incident and worsening WOMAC knee pain,” Wink and colleagues wrote. “Targeting varus thrust through non-invasive therapies could reduce the risk of knee pain in older adults with or at risk for knee OA.” – by Jason Laday
Disclosure: Wink reports research support from the NIH. Please see the study for all other authors’ relevant financial disclosures.