ACR Meeting Abstracts

ACR Meeting Abstracts

  • Meetings
    • ACR Convergence 2024
    • ACR Convergence 2023
    • 2023 ACR/ARP PRSYM
    • ACR Convergence 2022
    • ACR Convergence 2021
    • ACR Convergence 2020
    • 2020 ACR/ARP PRSYM
    • 2019 ACR/ARP Annual Meeting
    • 2018-2009 Meetings
    • Download Abstracts
  • Keyword Index
  • Advanced Search
  • Your Favorites
    • Favorites
    • Login
    • View and print all favorites
    • Clear all your favorites
  • ACR Meetings

Abstract Number: 2651

Associations Between Body Mass Index and Physical Activity Following Total Knee Replacement

Carol A. Oatis1, Wenjun Li2, Milagros Rosal3, David Ayers2 and Patricia D. Franklin2, 1Physical Therapy, Arcadia University, Glenside, PA, 2Orthopedics and Physical Rehabilitation, University of Massachusetts Medical School, Worcester, MA, 3Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA

Meeting: 2012 ACR/ARHP Annual Meeting

Keywords: body mass, Knee, physical activity and total joint replacement

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print
Session Information

Title: Orthopedics, Low Back Pain, and Rehabilitation

Session Type: Abstract Submissions (ACR)

Background/Purpose: In 2009 over 620,000 total knee replacement (TKR) surgeries were performed. That number is expected to increase to 3.5 million annually by 2030. On average, physical activity and functional ability remain diminished one year post TKR when compared to age matched controls. Many patients who undergo TKR are obese.  The purpose of this study was to examine the relationship of preoperative body mass index (BMI) to objectively measured physical activity levels at 6 months post TKR.

Methods: Subjects were 179 participants of an NIH funded RCT of telephone support intervention following unilateral primary total knee replacement (TKR).  Participants were stratified by BMI (< 30; 30-35; > 35). Participants were asked to wear an accelerometer (Step Activity Monitor™) at the ankle for four consecutive days (2 weekday; 2 weekend) before surgery and at 8 weeks and 6 months post operatively.  The accelerometer monitored the number of steps taken daily. Valid wear days required a minimum of 10 hours of wear time. 

Results: Participants were 68% female with a mean (SD) age of 65.1 (8.61). Mean (SD) BMI at baseline was 32.5 (5.24).  All 179 participants wore the accelerometer preoperatively. 174, 163 and 168 participants had at least one valid wear day preoperatively, at 8 weeks and 6 months after surgery respectively. Mean days worn was 3.3 days.  Participants with BMI > 35 (n=53) took fewer steps than those with BMI < 35 (n=121) preoperatively, at 8 weeks post surgery (BMI > 35, n = 46 and BMI < 35, n = 117) and at 6 months post surgery (BMI > 35, n = 50 and BMI < 35, n = 118) (p < .01) (Figure). At 6 months post surgery, mean steps (SD) were greatest in those with BMI < 30, 8845 (3731), fewer in those with BMI between 30 and 35, 8688 (3386), and fewest in those with BMI > 35, 7196 (3299).  Change in daily steps from baseline to 6 months was similar across all BMI groups.

Conclusion: Subjects with grade 2 obesity or greater (BMI >35) are less physically active throughout the perioperative period of TKR than those with lower BMI.  However high BMI does not preclude improvements in physical activity levels following TKR. An understanding of the association between obesity and physical activity can help inform patients’ and clinicians’ expectations for post-TKR gain and may focus interventions not only on the knee impairments following TKR but also on the modifiable risks to optimal gains in physical activity following TKR. Risk factors such as BMI may be addressed pre- and post-operatively.

 


Disclosure:

C. A. Oatis,
None;

W. Li,
None;

M. Rosal,
None;

D. Ayers,
None;

P. D. Franklin,

Zimmer, Inc.,

2.

  • Tweet
  • Click to email a link to a friend (Opens in new window) Email
  • Click to print (Opens in new window) Print

« Back to 2012 ACR/ARHP Annual Meeting

ACR Meeting Abstracts - https://acrabstracts.org/abstract/associations-between-body-mass-index-and-physical-activity-following-total-knee-replacement/

Advanced Search

Your Favorites

You can save and print a list of your favorite abstracts during your browser session by clicking the “Favorite” button at the bottom of any abstract. View your favorites »

All abstracts accepted to ACR Convergence are under media embargo once the ACR has notified presenters of their abstract’s acceptance. They may be presented at other meetings or published as manuscripts after this time but should not be discussed in non-scholarly venues or outlets. The following embargo policies are strictly enforced by the ACR.

Accepted abstracts are made available to the public online in advance of the meeting and are published in a special online supplement of our scientific journal, Arthritis & Rheumatology. Information contained in those abstracts may not be released until the abstracts appear online. In an exception to the media embargo, academic institutions, private organizations, and companies with products whose value may be influenced by information contained in an abstract may issue a press release to coincide with the availability of an ACR abstract on the ACR website. However, the ACR continues to require that information that goes beyond that contained in the abstract (e.g., discussion of the abstract done as part of editorial news coverage) is under media embargo until 10:00 AM ET on November 14, 2024. Journalists with access to embargoed information cannot release articles or editorial news coverage before this time. Editorial news coverage is considered original articles/videos developed by employed journalists to report facts, commentary, and subject matter expert quotes in a narrative form using a variety of sources (e.g., research, announcements, press releases, events, etc.).

Violation of this policy may result in the abstract being withdrawn from the meeting and other measures deemed appropriate. Authors are responsible for notifying colleagues, institutions, communications firms, and all other stakeholders related to the development or promotion of the abstract about this policy. If you have questions about the ACR abstract embargo policy, please contact ACR abstracts staff at [email protected].

Wiley

  • Online Journal
  • Privacy Policy
  • Permissions Policies
  • Cookie Preferences

© Copyright 2025 American College of Rheumatology