Diabetes and your knees

How diabetes affects the knee

Diabetes is common in Qatar and across the Gulf, so many patients who come with knee problems also manage their blood sugar every day. Diabetes does not cause most knee injuries, but it changes how tissues behave and heal.

Raised blood sugar over time can make ligaments, tendons and the joint capsule stiffer and less elastic. Many people with diabetes are also carrying extra weight, which adds load to the knee and is linked with osteoarthritis. Nerve damage in the feet and legs, called neuropathy, can reduce balance and the ability to feel early warning pain. Each of these affects how a knee problem is assessed and treated.

Knee pain and non-surgical treatment

Treatment for most knee conditions is the same with or without diabetes: activity changes, physiotherapy, weight management where relevant, and painkillers chosen to suit your other medicines and kidney function. Regular exercise helps both the knee and blood sugar control, so staying active is doubly worthwhile.

A few points are specific to diabetes.

• A steroid injection into the knee can raise blood sugar for a few days afterwards, so check your levels more often and ask your diabetes team how to adjust your medicines.
• Anti-inflammatory tablets are not suitable for everyone, particularly if your kidneys are affected, so ask your doctor or pharmacist before using them.
• A knee that becomes suddenly hot, red and very swollen needs urgent assessment, because joint infection is more likely when diabetes is present.

Infection and wound healing

Diabetes increases the risk of infection after any operation, including knee surgery, and wounds may heal more slowly. The risk is closely linked to how well blood sugar is controlled around the time of surgery, so it is one of the factors you can influence most.

Before surgery, your skin is checked for cuts, ulcers or infections, particularly on the legs and feet, and these are treated first. After surgery, keep the wound clean and dry as instructed, do not apply creams unless advised, and check it daily. Tell the team promptly about increasing redness, warmth, discharge, a wound that reopens, or a fever.

Blood sugar before surgery

If you are planning knee surgery, your blood sugar control over the past few months is reviewed with a blood test and your diabetes doctor's advice. If control is poor, surgery may be postponed while it is improved, because this lowers the risk of complications. There is no single number that applies to everyone; the decision depends on your overall health and the type of operation.

• Bring a list of all your diabetes medicines and insulin doses to the pre-operative assessment.
• Follow the instructions you are given on which medicines to stop or change before surgery, and do not change them on your own.
• Tell the team if you have problems with your kidneys, heart, eyes or feet.
• If you use a glucose sensor or insulin pump, ask how it will be managed during the hospital stay.

Stiffness and recovery

People with diabetes are more prone to stiffness after knee surgery, because scar tissue may form more readily around the joint. This is why early, regular movement and physiotherapy matter so much. Doing your bending and straightening exercises every day in the first weeks is one of the most effective ways to reduce stiffness.

Recovery may take a little longer, and pain, stress and reduced activity can all upset blood sugar levels after surgery. Check your levels more often in the first weeks, keep in touch with your diabetes team, and report a knee that stops improving or becomes stiffer rather than looser.

Knee surgery decisions with diabetes

Diabetes on its own rarely rules out knee surgery, including knee replacement. It does change the balance of risks and benefits, and it makes preparation more important. In some patients the plan is to improve blood sugar, weight and fitness first, and to operate once these are in a better place.

At Aman Hospital, Dr. Pablo Gelber discusses the expected benefit of surgery, the specific risks for you, and how to prepare, alongside your diabetes doctor or physician. Bring your recent blood results and medicine list to the consultation.