Knee pain, common complaint in women

19th December 2011 - New UK research shows 63% of women age 50 and over reported some type of knee pain during a 12-year period. They were more likely to experience persistent pain if they had a higher body mass index (BMI), previous knee injury, or osteoarthritis (OA).

Osteoarthritis is a leading cause of worldwide disability with pain the most troublesome symptom experienced by patients. It's a condition that affects the joints and is the most common type of arthritis in the UK. Around one million people see their GP about it and the NHS in England and Wales performs over 140,000 hip and knee replacement operations every year.

The main objective of the study was to understand the prevalence and predictors of knee pain. Lead author, Nigel Arden, a Professor of Rheumatology at the University of Oxford said in a press statement that this was "the first step in developing comprehensive pain assessment plans that could lead to more targeted treatment options for those burdened by OA".

Arthritis Research UK

Jane Tadman from Arthritis Research UK, the medical research charity which funds the Chingford Study, on which the findings are based said via e-mail: "This study provides further evidence of what we already know: that obesity, ageing and having a previous injury all contribute to the development of osteoarthritis of the knee, and that associated knee pain fluctuates over time.  

"It provides a strong mandate for our forthcoming research into arthritis caused by sports injuries, and examining the effects of musculoskeletal ageing and how this can possibly be reduced through diet and exercise.

"We’d encourage anyone with knee pain to move it or lose it; to keep moving and be and active and mobile as possible to keep pain and stiffness at bay."

The study

For this latest study researchers used data obtained from participants of the Chingford Study which looks at OA and osteoporosis. More than 1,000 women between the ages of 44 and 57 took part.

At the end of the 12-year study, data relating to self-reported knee pain was analysed and used to classify participants into four pain groups: those with no symptoms, persistent, incident (pain that arises as a result a movement or activity) and intermittent symptoms.

The team found a prevalence of 44% for "any days of pain" and 23% for "pain on most days of the previous month". Of those experiencing "any pain" in the preceding month 9% had persistent pain; 24% reported incident pain; and intermittent pain was seen in 29% of women.

Predictors

The researchers determined that a higher BMI predicted persistent and incident pain patterns, while OA was a predictor of persistent pain. Those reporting knee injury were likely to have persistent or intermittent pain patterns.

The authors suggest a main strength of this study is that it describes the natural history of knee pain over a long-term period. They say it has confirmed the presence of different patterns of pain, with a significant proportion of women demonstrating intermittent symptoms.

Professor Arden concludes: "Validation of our findings through reproduction in other patient groups is needed to advance knowledge of knee pain predictors that will ultimately enhance prevention and treatment strategies for those with OA."

Details of this longitudinal study are available in Arthritis & Rheumatism, a journal published by Wiley-Blackwell on behalf of the American College of Rheumatology (ACR).