Influence of severe knee pain, meniscus surgery and knee arthroplasty on physical ability: an observational study of 114 949 adults in the CONSTANCES cohort.

Background: The knee is one of the major sites of musculoskeletal pain, yet few large-scale studies have evaluated the impact of knee disorders on physical limitations. Our objective was to describe this impact in a large-scale population study.

Methods: We included subjects of working age from the CONSTANCES cohort, from its inception. Four groups were distinguished according to their medical history: whether they had knee arthroplasty (KA), meniscus surgery, severe knee pain, or none of these. Outcomes assessed for physical limitations were self-reported limitations in the last 6 months due to health problems, limitation on carrying 5 kg on 10 m and a 3-metre length rapid gait speed test (for participants aged >45). Associations between knee groups and patients' characteristics and physical limitations were analysed using logistic regression. Robust associations were deemed relevant if their ORs were higher than 2 and their p value lower than 0.0001.

Results: Of the 114 949 individuals, 99 052 (86.2%) were in the 'no pain and no surgery' group, 14 740 (12.8%) were in the severe knee pain group, 1019 (0.89%) had meniscus surgery and 138 (0.12%) had KA. Severe knee pain and KA groups showed a similar profile (they were less at work, reported more deterioration in their health and had more limitations).

Conclusion: Almost 14% of the sample had knee disorders. Subjects reporting severe knee pain or who had KA reported more important physical limitations then subjects who reported neither severe knee pain nor knee surgery.