Longitudinal Relationship Between Tibiofemoral Contact Stress at Baseline and Worsening of Knee Pain Over 84 Months in the Multicenter Osteoarthritis Study.
Kaitlin G Rabe, Tyler J Stockman, Andrew M Kern and 7 others
PMID 34620738WHAT IT FOUND
Knees with high baseline contact stress had double the odds of worsening pain over seven years compared to low-stress knees.
However, this link disappeared when adjusting for BMI and leg alignment, suggesting those factors may explain the risk.
Key findings
01Participants in the highest tertile of baseline mean contact stress had 2.47 times the odds of worsening knee pain compared to the lowest tertile.
02Participants in the highest tertile of baseline peak contact stress had 2.49 times the odds of worsening knee pain compared to the lowest tertile.
03When BMI and hip-knee-ankle alignment were added to the models, the association between contact stress and worsening pain was no longer statistically significant.
STILL TO COME
How it was doneWhat they foundWhat it means for PTs
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The sample size dropped from 275 to 208 knees due to missing data or imaging issues, reducing the study's power. The contact stress model simplified cartilage properties and excluded the meniscus, which may affect accuracy. Participants received usual care during follow-up, so treatments could have influenced pain outcomes. The association between contact stress and pain was not significant after adjusting for BMI and alignment, suggesting these factors may confound the relationship.
Declared interests
Funded by the NIH; authors declared no conflicts of interest.
The easy way to misread this
Do not assume contact stress is an independent predictor of pain worsening. The significant association disappeared when adjusting for BMI and leg alignment, meaning these standard clinical factors may account for the risk.