Hip and knee replacements offer relief for Canadians suffering from pain and reduced mobility, but on average their function was not restored to the same levels as the general population enjoys, a new report shows.

Wednesday's report from Statistics Canada on hip and knee replacements compared health-related quality of life using hospital admission and survey data for 598 people who had surgery and more than 58,000 people aged 40 or older who had not received a hip replacement in the previous five years.

The surgical group showed differences in functional health depending on the diagnosis.

Patients with a main diagnosis of osteoarthritis regained more health, reporting six per cent less functional health for hip replacement and nine per cent less for knee replacement compared with the control group. But the hip fracture group reported 21 per cent less functional health.

"After surgery, patients with fractures do not regain health to the same degree as the osteoarthritis group," the report's authors said.

The results also showed that among people with osteoarthritis who had joint replacements, being underweight and having chronic conditions were linked to poorer health after surgery.

Osteoarthritis was the most common diagnosis among both hip replacement patients, 29.5 per cent, and knee replacement patients, 40 per cent.

In Canada, about 23,000 hip replacements and 38,400 knee replacements were done in 2006-07.