Objectively measured physical activity in patients with end stage knee or hip osteoarthritis.
BACKGROUND
Patients with lower extremity osteoarthritis (OA) have increased all cause and disease specific mortality compared to the general population and epidemiological data suggests that OA management should include increased physical activity.


OBJECTIVE
To measure physical activity assessed as daily energy expenditure and accumulated steps day-1 in patients with severe OA of the hip or knee and compare with healthy controls. Furthermore, to investigate if gender, age, BMI and affected joint influence measures of physical activity.


METHODS
Cross sectional study.


METHODS
Community.


METHODS
Fifty-one patients (49% women, age: 68±5 years, BMI: 28.4±4.6) with severe knee (N.=25) or hip (N.=26) OA scheduled for total joint replacement and 15 healthy population-based controls (53 % women, age: 68±5 years, BMI: 26.9±4.3).


METHODS
Subjects wore an accelerometer (SenseWear™ Pro2 Armband) on 5 consecutive days. Time on body, total energy expenditure, average intensity (METS), time being sedentary, time above 3 METS and numbers of steps day(-1) were calculated.


RESULTS
Patients had similar daily energy expenditure to controls (2632 vs. 2633 calories per day) but walked on average 29.3% fewer steps day(-1) (6632 vs. 8576 P=0.033). Gender and affected joint (hip or knee) did not influence the results. Age and BMI explained 15.4%-32.7% of the variation in total energy expenditure, average METS, time being sedentary, and steps day(-1).


CONCLUSIONS
The present data indicate a need for interventions improving walking ability in patients with severe hip and knee OA. This need is independent regarding gender and affected joint but higher for older and heavier patients. Simultaneously assessed measures of physical activity gave different results, raising concern about validity of physical activity measures in patients with lower extremity OA and indicating caution when comparing results from studies applying different measures.


CONCLUSIONS
It is of potential interest for patients and practitioners that a relative high physical activity is possible for end-stage OA patients since this may reduce the increased all cause and disease specific mortality.
Orthopedic Research Unit, Department of Orthopedics and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense, Denmark. ahlarsen@health.sdu.dk
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Holsgaard-Larsen
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Roos
D061725:Accelerometry / Q000295:instrumentation / Q000379:methods; D000367:Age Factors; D000368:Aged; D018771:Arthralgia / Q000150:complications / Q000209:etiology; D015992:Body Mass Index; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009043:Motor Activity / Q000502:physiology; D015207:Osteoarthritis, Hip / Q000503:physiopathology / Q000534:rehabilitation*; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000534:rehabilitation*; D012044:Regression Analysis; D012720:Severity of Illness Index; D012737:Sex Factors; D013548:Sweden; D016138:Walking / Q000502:physiology*