Knee Osteoarthritis

 

Osteoarthritis (OA) is a common musculoskeletal disorder which affects joints – typically the knees, hips, hands, feet, or spine. Healthy joints have a layer of hard tissue called cartilage over the ends of the bones which permits the joint surfaces to glide across each other smoothly. In osteoarthritis, this cartilage thins and the bone underneath becomes thicker, changes shape and sometimes begins to grow outwards, forming bony spurs; these changes are unfortunately associated with pain and poor joint function. These changes were examined in Hertfordshire using x-rays of the knees and hips; in addition, cohort members’ hands were examined for swellings typical of osteoarthritis.

Our research has shown that people with osteoarthritis at the hip and knee are more likely to walk and rise from a chair more slowly and are more likely to have difficulties with balancing (1).

We have also explored the different ways in which osteoarthritis is identified in clinical practice. It can be diagnosed by a healthcare professional using a combination of symptoms and clinical signs on examination. Diagnosis is also made on the basis of characteristic appearances of the joint which are seen on an x-ray. However, the overlap and agreement between the different ways of diagnosing osteoarthritis is poorly understood. Our Hertfordshire research has shown that there is modest agreement between knee osteoarthritis diagnosed using an x-ray, and knee osteoarthritis diagnosed by a healthcare professional by examination (2). This is relevant to clinical practice because it will help healthcare professionals to better understand the relationship between the clinical findings that they identify on examination of a patient and the images they see on x-ray.

Although osteoarthritis affects approximately 10% of the world’s population aged 60 years and older, its risk factors are not fully understood. Our research has found that influences acting before birth and in infancy affect risk of osteoarthritis in later life. People who were born small were more likely to have bony spurs in their hip joint in later life than people who were bigger at birth, and people who were small at one year were more likely to have bony spurs in their hip or knee, and also more likely to have symptoms of osteoarthritis in their hand (3). This research shows that there are risk factors for osteoarthritis which act across the lifecourse.

 

Reference List

  1. Edwards, M.H., et al., Relationships between physical performance and knee and hip osteoarthritis: findings from the European Project on Osteoarthritis (EPOSA). Age and Ageing, 2014. 43(6): p. 806-813.
  2. Parsons, C., et al., How well do radiographic, clinical and self-reported diagnoses of knee osteoarthritis agree? Findings from the Hertfordshire cohort study. SpringerPlus, 2015. 4(1): p. 1-5.
  3. Clynes, M.A., et al., Further evidence of the developmental origins of osteoarthritis: results from the Hertfordshire Cohort Study. J Dev Orig Health Dis, 2014. 5(6): p. 453-8.