Obesity linked to rise in knee replacement surgery

For those desperate to shift the pounds so they can become healthier and more active, life can sometimes seem a vicious cycle. Increased weight puts pressure on the knee, causing discomfort, and wear and tear, meaning exercise can be too painful. Not being able to exercise, though, usually leads to increased weight and more pressure on the knee joint.

New figures on joint replacement surgery for massively overweight patients point to the strain that obesity is causing the NHS. Eighteen thousand patients a year, who are classed as medically obese, require their hips or knees replaced; this is a fourfold increase since 2009 alone.

Since 2009, the number of knee replacements carried out in the NHS in England has risen from 76,071 to 91,436, costing the NHS almost £600 million a year. However, for obese patients the rise in knee replacements has outstripped the national average, going from 3,787 to 15,188.

Why does obesity affect your joints?

The UK is classified as one of the most obese countries in Europe, with over a quarter of adults recording a BMI that puts them into the obese category. If you were to name a health problem associated with obesity, then you might think diabetes or heart disease and it’s true that these are common health conditions that are linked to being massively overweight. However, arthritis is actually a more likely outcome of carrying too much weight.

Arthritis is caused by the breakdown of cartilage in the joints and there are many factors that can contribute to its development. However, it’s an undeniable fact that the more stress you put on the joint, the more likely that you will damage the cartilage; every pound of excess weight translates to four pounds of extra pressure on your knee.

Fat itself can also cause problems, not relating to the pressure the extra weight puts on your joints, as it can cause inflammation, a common factor identified in the development of arthritis. Carrying excess weight actually seems to be even more damaging to the knee than the hips; arthritis of the knee is a more common problem for obese patients than arthritis of the hip.

Knee replacement surgery is an effective procedure for those who are struggling to perform normal activities, but the longevity of knee replacement surgery is currently pegged at 15 to 20 years as long as the knee replacement is not put under ‘undue strain’.

As with much in medicine, not addressing the root cause of the problem means that often surgical solutions can only provide a temporary fix. Looking at alternative options, such as weight loss surgery in advance of joint replacement surgery, might be the answer to providing patients with the best possible quality of life.