The aim of this study was to assess the predictive value of functional performance and range of motion measures on outcomes after total knee arthroplasty.
This is a secondary analysis of two pooled prospective randomized controlled trials. Sixty-four subjects (32 men and 32 women) with end-stage knee osteoarthritis scheduled to undergo primary total knee arthroplasty were enrolled. Active knee flexion and extension range of motion, Timed Up and Go (TUG) test time, and 6-min walk test distance were assessed.
Preoperative measures of knee flexion and extension were predictive of long-term flexion (β = 0.44, P < 0.001) and extension (β = 0.46, P < 0.001). Acute measures of knee flexion and extension were not predictive of long-term flexion (β = 0.09, P = 0.26) or extension (β = 0.04, P = 0.76). Preoperative TUG performance was predictive of long-term 6-min walk performance (β = −21, P < 0.001). Acute TUG performance was predictive of long-term functional performance on the 6-min walk test, after adjusting for the effects of sex and age (P = 0.02); however, once adjusted for preoperative TUG performance, acute TUG was no longer related to long-term 6-min walk performance (P = 0.65).
Acute postoperative measures of knee range of motion are of limited prognostic value, although preoperative measures have some prognostic value. However, acute measures of functional performance are of useful prognostic value, especially when preoperative functional performance data are unavailable.
From the Rueckert-Hartman College for Health Professions, School of Physical Therapy, Regis University, Denver, Colorado (MJB); Department of Biostatistics & Informatics, University of Colorado Anschutz Medical Campus, Colorado School of Public Health, Aurora, CO (JMK); and Department of Geriatrics (WMK) and Department of Physical Medicine and Rehabilitation (JES-L), University of Colorado Anschutz Medical Campus, School of Medicine.
All correspondence and requests for reprints should be addressed to: Michael J. Bade, PT, PhD, Rueckert-Hartman College for Health Professions, School of Physical Therapy, Regis University, 3333 Regis Blvd, G-4, Denver, CO 80221-1099.
Supported by the National Institutes of Health (NIH) (K23 AG029978, R03 AR054538, T32 AG00279, UL1 RR025780) and the Foundation for Physical Therapy Promotion of Doctoral Studies II Scholarship.
The authors certify that no party having a direct interest in the results of the research supporting this article has or will confer a benefit on the authors or on any organization with which they are associated, and, if applicable, the authors certify that all financial and material support for this research (e.g., NIH or NHS grants) and work are clearly identified in the title page of this article.
Presented at the APTA Combined Sections Meeting in San Diego, CA, in January 2013.
Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article.