Patients with knee osteoarthritis who walk at a moderate-to-vigorous intensity may lower their risk of total knee arthroplasty, or joint replacement surgery, according to new research findings presented this week at the 2018 ACR/ARHP Annual Meeting.
Osteoarthritis (OA) is a common joint disease that most often affects people in middle age or later. OA is a painful disease that affects the entire joint, involving the cartilage, joint lining, ligaments and bone. OA is characterized by the breakdown of the cartilage (the tissue that cushions the ends of the bones between joints), bony changes of the joints, deterioration of tendons and ligaments, and various degrees of inflammation of the joint lining (called the synovium).
This study was conducted to help answer the question: Does walking more increase a patient’s risk of structural worsening in the knee joint and total knee arthroplasty (TKA)? One reason for prior inconsistent, contradictory evidence in this area is that patients may walk at different intensities. Researchers at the University of Delaware conducted a study to learn more about the association of walking intensity with TKA risk over a five year period in adults with or at high risk of knee OA.
“We wanted to know if walking was helpful or harmful for getting a knee replacement for people who have knee OA,” said Hiral Master PT MPH, a PhD candidate in biomechanics and movement science at the University of Delaware and the study’s co-author. “Walking may exacerbate knee pain and further make things worse, but on the other hand, walking is helpful to build and maintain strength, and may prevent the development of difficulty functioning.”
The study used data from the Osteoarthritis Initiative (OAI), and included participants who did not have TKA at or before a 48-month follow-up visit. The researchers quantified time spent in different walking intensities by step cadence recorded by an accelerometer. They defined less than one step/minute as non-walking, 1-49 steps/minute as very light walking, 50-100 steps/minute as light walking, and more than 100 steps/minute as moderate to vigorous walking.
They quantified time to TKA in months from the baseline visit date to the surgery date if it occurred in the subsequent five years, or at the 108-month visit. Any participants who did not have TKA at the 108-month visit or who were lost to follow-up were censored. The researchers examined the effects of replacing time spent not walking with walking at either very light, light or moderate-to-vigorous intensities with TKA risk over five years. They also repeated these analyses on just participants with radiographic and symptomatic knee OA.
At baseline, there were 1,854 participants without TKA who wore their accelerometer for at least four out of seven days. They had a mean age of 65 years, a mean body-mass index (BMI) of 28.4 and 55 percent were female. Over five years, 108 participants received a TKA. Those participants who replaced five minutes per day of non-walking time with five minutes per day of walking at moderate-to-vigorous intensity reduced their risk of TKA by 16 percent, the study’s findings showed. Very light and light intensity walking had no effect. Similar results were found when the researchers analyzed samples of patients with radiographic and symptomatic knee OA.
“Our findings suggest that small changes in walking behavior may delay the need for TKA in people with or at high risk of knee OA. Clinicians should consider encouraging their patients with or at high risk of knee OA to go for a brisk walk for five to 10 continuous minutes each and every day,” said Master.
|This research was supported by the National Institutes of Health.|
Friend or Foe: Does Walking at Higher Intensities Increase or Decrease the Risk of Total Knee Arthroplasty over Five Years? [abstract]. Master H, Thoma L, Christiansen M, Mathews D, Macri E, Ziegler M, Stefanik JJ, White D. Arthritis Rheumatol. 2018; 70 (suppl 10). Abstract #1166 2018 ACR/ARHP Annual Meeting. October 19-24, 2018 in Chicago
Physical activity status by pain severity in patients with knee osteoarthritis: a nationwide study in Korea, Hye-Young Shim, Mira Park, Hee-June Kim, Hee-Soo Kyung and Ji-Yeon. BMC Musculoskeletal Disorders 2018 19:380 https://doi.org/10.1186/s12891-018-2301-6
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