Pre-operative predictors of early mobility and knee motion in patients undergoing a total knee arthroplasty

Abstract Objective To identify pre-operative patient characteristics associated with early recovery of knee range of motion and ambulation without an assistive device after TKA. Design 95 subjects completed testing 2-4 weeks prior to surgery and 1 month after surgery. Binary logistic regression models were performed using patient’s pre-operative measures to predict knee functional knee range of motion (ROM) and early independent mobility 1 month after TKA. Functional ROM was defined as active knee flexion ≥100° and Ext ≤5°. Independent mobility was defined as no need for an assistive device during the Six Minute Walk (6 MW) test. Nagelkerke’s R2, and model and step significance were assessed. Results One month after surgery, 56 (58.9%) subjects did not have functional ROM. 75 (78.9%) subjects did not use an AD during the 6 MW. There were no significant predictors of early ROM recovery (R2=0.142, p-value = 0.06) or independent mobility (R2 N=0.138, p-value = 0.116). Conclusion Pre-operative measures were not predictive of early recovery rates one month after TKA, making pre-operative ROM and mobility risk stratification difficult. Future research should evaluate other factors, such as surgical pain and swelling, which may be better predictors of early outcomes after TKA.