DOS 2017

DOS Kongressen 2017 ·

Differences in level of physical activity in patients with

knee osteoarthritis, patients with knee joint replacement

and healthy subjects measured with an accelerometer-

based method

Rikke Daugaard, Marianne Tjur, Maik Sliepen, Dieter Rosenbaum, Bernd Grimm, Inger

Mechlenburg

Ortopaedic Research Unit, Aarhus University Hospital, Denmark; Ortopaedic Re-

search Unit, Aarhus University Hospital, Denmark; Institut für Experimentelle

Muskuloskelettale Medizin, Universitätsklinikum Münster, Germany; Institut für Ex-

perimentelle Muskuloskelettale Medizin, Universitätsklinikum Münster, Germany; ,

Zuyderland Medical Center, Heerlen, Netherlands; Ortopaedic Research Unit, Aarhus

University Hospital, Denmark

Background:

Knee osteoarthritis (KOA) causes impairment through pain, stiffness

and malalignment and knee joint replacement (KJR) may be necessary to alleviate

such symptoms. There is disagreement whether patients with KJR increases their

level of physical activity after surgery.

Purpose / Aim of Study:

The aim of this study is to investigate whether patients

with KJR have a higher level of physical activity than patients with KOA, as measured

by accelerometer-based method. Furthermore, to investigate whether patients

achieve the same level of activity as healthy subjects five years post TJR.

Materials and Methods:

Fifty-four patients with KOA (29 women, mean age

62±8.6, mean BMI 27±5), 53 patients who had KJR five years earlier (26 women,

mean age 66±7.2, mean BMI 30±5) and 171 healthy subjects (76 women, mean

age 64±9.7, mean BMI 26±5) were included in this cross sectional study. The level

of physical activity was measured over a mean of 5.5 days with a tri-axial acceler-

ometer mounted on the thigh. Number of daily short walking bouts of <10 seconds

duration, number of daily steps, and number of daily transfers from sitting to stand-

ing were calculated. Data was analyzed through linear regression and adjusted for

age, sex and BMI.

Findings / Results:

Patients with KJR had 10.1 fewer short walking bouts (p=0.04),

745 fewer steps (p=0.19) and 6.2 fewer transfers (p=0.09) per day than patients

with KOA. In addition, patients with KJR performed 21.7 fewer short walking bouts

(p=0.001), 281 fewer steps (p=0.60) and 3.2 fewer transfers (p=0.32) per day

than healthy subjects.

Conclusions:

Patients with KJR do not seem to be more physically active than pa-

tients with KOA. Neither do the seem to be as active as healthy subjects, However,

the results may suffer from selection bias and thus the results ought to be confirmed

in a bigger cohort study.

No conflicts of interest reported