Long-term study highlights benefits and limitations of knee replacement surgery

A new study has offered a new insight into the long-term benefits of total knee replacement surgery for people with arthritis, as well as the limitations that can undermine its effectiveness.

Led by the Arthritis Research UK Sports, Exercise and Osteoarthritis Centre of Excellence at the University of Oxford, the research identified a range of medical and social factors that could predict long-term outcomes of knee replacement surgery, while also demonstrating the significant pain relief benefits the majority of recipients enjoy.

Long-term benefits

For this research, a group of 1,980 people receiving total knee replacement surgery were assessed before the procedure and again ten years later to learn more about their outcomes and individual circumstances.

It was found that all of those receiving knee replacement surgery reported substantial improvements in pain over ten years, although pain did begin to worsen over time. This shows that surgery can be considered an effective treatment for knee pain.

Meanwhile, knee function was also improved, though markedly less so than pain relief, suggesting that techniques could perform better in terms of improving joint movement and stability.

Factors that could affect the effectiveness of treatment

However, the report also revealed a number of factors could be associated with poorer long-term outcomes and dissatisfaction with knee replacement. These included obesity, poor mental wellbeing, living in a deprived area, experiencing other unrelated disorders, having a history of knee surgeries and suffering more severe knee problems at the outset.

The same factors predicted reduced function and increased pain in the short, medium and long term, although functional outcomes were easier to predict than pain. Patients in these categories may require new or improved approaches to treatment.

Implications of the study

Currently, it is estimated that up to one in five people are unhappy with the long-term effects of their knee replacement. This study offers insights into why this is the case, underlining the need for more mobile and stable joints to be developed in future.

Additionally, having this information available will help doctors to more accurately inform people considering knee replacements about what they will probably experience in terms of pain relief and joint mobility, meaning more realistic expectations can be set.

Arthritis Research UK's view

Natalie Carter, head of research liaison and evaluation at Arthritis Research UK, said: "Knee replacement surgery offers greater mobility and reduced pain in the majority of people who undergo this operation. It's reassuring to see in this study that these immediate benefits continue into the longer term.

"Despite this high success rate, we need to do more to ensure that people who are not fully satisfied with their surgery in the long term do better in future. We hope that in identifying the factors that affect the outcomes of treatment, this study will lead to new and improved understanding in how to address this and further push back the limits of arthritis."

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