The value of post-acute exercise programs following total knee replacement surgery has been called into doubt with Australian research showing they offered no additional benefit for osteoarthritis patients.

The multicentre study of 422 patients found no significant differences between those randomised to an eight-week group exercise program about six-weeks after hospital discharge versus usual care.

About 70% of all patients reported a 50% or more reduction in knee pain and activity limitation at 12-months follow-up however significant leg power and strength deficits remained in both groups. Deaths, hospital re-admissions and adverse effects were similar in each group.

 Lead researcher Associate Professor Marlene Fransen, from the University of Sydney, said the team had hoped more intensive exercise in the treatment group would have helped improve patient outcomes.

“While all patients are looking good in terms of self-reported pain at 12 months, they are left with marked deficits in leg strength and power compared to population norms. This makes them vulnerable to future mobility problems,” she said.

“It might be that we need to set targets for muscle strength and power if we want to help patients protect their knee and avoid problems in three to four years.”

She said performance measures such as stair-climb power, 50-foot walk speed and knee flexion and extension strength were simple tools and inexpensive to perform.

“As with diet and exercise in general, motivation of this group is important. 60% of our cohort were obese and largely sedentary so maybe we expected too much from them too early.”

She said delaying the program until patients were able to exercise at a higher intensity or extending the duration of the exercise program may have led to more differentiation between the groups.

However the research found adherence to the exercise program was also poor with only 50% attending the full 16 sessions.

“Certainly flexibility in the provision of exercise programs could make it easier for them to attend especially when patients have returned to full-time work.”