Among adults undergoing knee arthroplasty (KA), approximately one-fifth continue to have persistent pain, poor function, or both, a recent study found. Although the poor pain and function trajectory types tend to go together within persons, a significant number experience either poor pain or function but not both, suggesting heterogeneity among persons who do not fully benefit from KA. 384 patients took part in the Knee Arthroplasty Skills Training randomized clinical trial. Pain and function were assessed at 2-week pre- and 2-, 6-, and 12-months post-surgery. Piecewise latent class growth models were used to estimate pain and function trajectories and pre-surgery variables were used to predict trajectory types. Researchers found:
- There was strong evidence for 2 trajectory types, labeled as good and poor, for both WOMAC Pain and Function scores.
- Model estimated rates of the poor trajectory type were 18% for pain and function.
- Pain catastrophizing and number of painful body regions were significant predictors of poor pain and function outcomes.
- Outcome-specific predictors included low income for poor pain and baseline pain and younger age for poor function.
Dumenci L, Perera Ram Keefe FJ, et al. Model-based pain and function outcome trajectory types for patients undergoing knee arthroplasty: A secondary analysis from a randomized clinical trial. [Published online ahead of print January 17, 2019]. Osteoarthritis Cartilage. doi:10.1016/j.joca.2019.01.004.