Activity After Total Hip Replacement

Everybody knows exercise is good for you. But when arthritis pain gets you down, it's hard to stay active. Just how active are folks after a total hip replacement (THR)? That's the question human movement scientists from the Netherlands explored in this study.

They compared the activity level of various groups of patients with and without a THR. They started with 273 patients who had a THR and compared their activity level against 273 people of the same age and sex who did not have a THR. Then they compared the patients with a THR who were under 65 years of age with patients who had a THR who were 65 years old and older.

They also compared patients in different Charnley classifications. These categories place patients in one of three groups. Category A is for patients with problems in one hip that interfere with activity. Category B means both hips are a problem but the rest of the body is normal. Category C is for patients with a major health problem that interferes with activity. This could be rheumatoid arthritis, stroke, diabetes, or some other limiting condition.

Everyone filled out the Short QUestionnaire to ASsess Health-Enhancing Physical Activity (SQUASH). This tool is used to identify the amount of physical activity each person engaged in on a regular basis. There are questions about commuting, household activities, and sports or recreational activities. Other areas assessed include work and school activities.

The Metabolic Equivalent (MET) value was used to determine intensity of activity. One MET is equal to the amount of energy used while sitting quietly. For this study, activity intensity was labeled as light, moderate, and vigorous. Light intensity was any activity performed between two and four METs. Moderate intensity was a MET value of four to less than 6.5. Anything with a MET value of 6.5 or greater was considered a vigorous activity.

The categories of intensity were slightly different for adults 55 or older. Light intensity was two to less than three METs. Moderate activity was three to less than five METs. And activities with METs five and above was considered vigorous intensity for older adults. METs less than two was not enough activity to count.

Analysis of the data collected showed that there wasn't much difference between the two main groups (patients with a THR, subjects without a THR). Physical activities in their daily lives was mostly in the household and leisure categories. Overall younger people in both groups were more active and spent a large part of time at work.

Intensity was almost equal between the two groups. The THR group did spend more time in the category of light intensity activities and less time in vigorous activities compared with the comparison group. But the differences weren't significant from a statistical perspective. Not surprising, people in Charnley Class C (significant health condition) reported the least amount of activity (time and intensity). They were older than patients in the other Charnley classes.

The authors report that compared with activity guidelines set forth by the American Medical Association and the American College of Sports Medicine, people in both groups need to become more physically active and exercise more. At the time of the study, the guidelines were for 30 minutes (or more) of moderate-to-intense physical activity five days/week. Daily activity was advised.

Since then, the recommendations have been updated. Now it is recommended that adults exercise 30 minutes (or more) at a moderate intensity aerobic level at least five days/week. Alternately, vigorous-intensity aerobic activity for 20 minutes three days/week is acceptable. Combining the two (moderate and vigorous-intensity activity) to meet the recommendation is also possible.

The authors conclude that patients with a THR are doing well keeping up with normal, healthy adults. That was the case despite having had a major operation and being told to avoid excessive activity in order to preserve the implant for as long as possible.

The authors suggest further study into the habitual physical activity of patients after a THR is needed. This study just represents one group of patients in one country who had surgery with one surgeon. Results could be different for other patient groups.



References: Robert Wagenmakers, MD, et al. Habitual Physical Activity Behavior of Patients After Primary Total Hip Arthroplasty. In Physical Therapy Journal. September 2008. Vol. 88. No. 9. Pp. 1039-1048.