image an obese person sitting on the side of a hospital bed suffering from knee pain, needing a weight loss programme, holding the painful area with both hands

Weight loss and obesity-related knee pain

Weight loss, obesity and knee pain discussed by local specialists Damian Clark (knee surgeon, NBT), Jim Hewes (bariatric surgeon, NBT) and Hyunkee Kim (GP, Eastville Medical Centre).




One-quarter of adults in the UK (13 million) are obese (BMI > 30kg/m2). Rates are on the rise with a projected 17 million adults by 2030. Obesity is a risk factor for diabetes, heart disease and stroke. It is a causative factor in up to 20 different types of cancer. This is causing an enormous financial burden of over £4bn per year (5% of total NHS budget) spent on its management and consequences.

One-fifth of people in their 50s have painful knee osteoarthritis in at least one knee. This is becoming more common as we age rising to two in five of those aged over 80. More than 6 million people in the UK currently have painful knee osteoarthritis.

For those with a BMI of more than 35, there is a 14 times increase in the incidence of knee osteoarthritis.


Does knee replacement surgery benefit people who are overweight?


Several studies have evaluated this and the outcomes are good. Those with a BMI of more than 40 tend to have less functional improvement than patients with lower BMIs. Improvement may also take longer. Risk of complications is higher such as infection, wound healing problems, respiratory complications and venous thromboembolism. The joint replacement itself might “wear out” faster and the implant may loosen from the bone.


Arthritis and exercise?


Arthritis does make exercise more challenging. Chronic pain has a negative impact on step count and calorie expenditure. Studies have shown that even modest weight loss and exercise can help reduce pain. This increases the ability to perform everyday activities. Interestingly, loading a joint during exercise has shown to be protective of cartilage. This month’s JBJS reported that marathon runners have healthier cartilage than non-marathon runners with the same age and BMI.


What are the alternatives to knee replacement surgery?


The ADAPT study compared the benefits of diet, exercise and combined dietary and exercise classes. This trial ran for 18 months and included more than 300 people. The findings were that:

• Weight loss advice alone provided no benefit.
• Exercise classes alone provided minor benefit.
• Dietary classes provided greater benefit.
• Combined exercise classes and weight loss classes provided the greatest benefit.


What supported weight loss services can I refer patients to in the community?


In Bristol, GPs and physios can access Tier 2 and 3 management services providing 12 free slimming world or weight watchers classes. READ MORE

Exercise programmes for people with medical needs. READ MORE

For children (age 2–16) a more intensive programme can also include an intervention in the GP surgery and lifestyle advice for the entire family. READ MORE

Tier 3 weight management referrals are also available through Criteria Based Access. READ MORE


What weight loss services do NBT offer?


People who are morbidly obese may benefit from bariatric (weight loss) surgery. This safe and effective operation promotes significant long-term and sustained weight loss. It is the most cost-effective treatment ever evaluated by NICE with 90% of patients discharged less than 23 hours after surgery. People whose weight puts them at risk of developing or worsening the symptoms of osteoarthritis can be considered for this.

NBT offers a full range of surgical and non-surgical weight loss services and has excellent outcomes. These include sessions with dieticians, psychologists, endocrinologists, surgeons and nurse practitioners.

Patients are eligible for a referral if they have a BMI > 40 or BMI > 35 and obesity-related comorbidity such as T2DM, sleep apnoea, intra-cranial hypertension, metabolic syndrome, etc.

Referrals made via the North Bristol NHS Trust website. READ MORE

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