Knee Problems of the Super Obese

Super obesity is a significant public health concern in the United States. It’s the leading preventable cause of death and is linked to many chronic diseases such as diabetes and heart disease.

The knee joint is especially vulnerable to injury in healthy-weight active people and those who are overweight. But until today’s Mayo Clinic presentation, no one had published results of what happens to knee implants under the stress of extreme extra weight known as “super obesity“.

Super Obesity is a Body Mass Index (BMI) greater than 50. Normal-weight BMI ranges from 19 to 25.

Replacing a knee joint is a common surgical procedure called “Total Knee Arthroplasty. “ A statistically powerful sample to determine how implants fare in this population is less common in superobese patients. 

Between 1996 and 2006, Mayo Clinic surgeons treated 105 of these surgically and medically demanding patients. The patients had a mean BMI of 53.6, and the average age at surgery was 61. Their outcomes have followed an average of three years after surgery.

Super Obesity

Results showed:

  • Overall, 40.6 percent had surgical complications, and 14.3 percent had medical complications – including two deaths after the surgery.
  • Surgical complications included 20 knees with prolonged wound drainage -increasing the chance of deep infection of the implant.
  • Nineteen cases needed additional operations to trim slowly healing wound edges, treat deep infections, or repair failed implants.

“As with hip replacement in the super obese patient, total knee arthroplasty also is associated with a markedly higher complication rate compared to patients of normal weights,” says Mayo Clinic orthopedic surgeon David Lewallen, M.D., senior author of the study.

“The real concern is that clinicians and patients must be aware of that fact when making treatment decisions. In general, this group of patients is in desperate circumstances – and we want to help them. To do that, we are trying to get the data out there that will guide the management of the superobese patient. A big part of that has to be helping them lose weight before knee arthroplasty whenever possible.”

Mayo Clinic, through a dedicated focus on individual patient needs, provides diagnostic and treatment services in every sub-specialty at its locations in Rochester, Minnesota, Jacksonville, Florida, and Phoenix and Scottsdale, Arizona.

Obesity and Knee Injury

Super obesity leads to many changes in the joints, ligaments, and muscles. With these changes comes a greater risk for injury. The joint at the bottom of the leg most commonly suffer from injuries. The knee is where all of the pressure from walking and standing falls. This can cause wear-and-tear or damage to the cartilage that cushions the bones in this area. When that cartilage wears away, it causes pain, stiffness, and swelling in the joint.

If you’re obese, there are ways you can help prevent knee injuries by controlling your weight loss efforts and starting an exercise routine.

In terms of weight loss: make sure you are eating a healthy diet (low in saturated fat), planning your meals ahead of time, and utilizing calorie counting to track your daily intake. A diet low in sugar reduces inflammation, so cutting sugar wherever possible is essential.

If you’re exercising: start with light exercises like walking or cycling before gradually moving on to more intense workouts like running or jumping rope. It’s also important to go slow when adding new activities so that your body has time to adjust before taking on new challenges. 

Finally, stay consistent with your routine. The more you work out over time, the better it is for your body and joints!

Why do Obese People Experience More Knee Injuries?

There are several reasons why obese people experience more knee injuries. Some of the most common reasons include:

  • A more significant amount of weight can cause more strain on the knees.
  • Inadequate alignment causes more considerable stress on the knees.
  • Lack of muscle strength in the quadriceps and hamstrings may contribute to instability in the knee joints.
  • Poor sleep habits often worsen knee pain.
  • Obesity alters hormone levels, affecting bone density and strength in your lower legs.

How Can Super Obesity Cause Knee Problems?

Being super obese causes knee problems in different ways:

  • Increased load on the knee – The fat accumulating on the body, especially around the abdomen, legs, and thighs, puts tremendous pressure on the knee joint. This may cause the knee cartilage to degenerate prematurely, resulting in knee pain and stiffness.
  • Worsened knee alignment – Excess fat on some body parts, including the abdomen and the inner thighs, pushes the knees inwards. This may result in an abnormal knee alignment, leading to knee pain and arthritis.
  • Increased pressure on the knee joint – Excess fat around the knee joint may press on the joint and make it stiffer, which may make walking difficult. This may lead to severe knee pain, even in people with normal knee joints.

What can be Done to Prevent Knee Injuries from Excess Weight?

Losing weight is the best way to prevent knee injuries from excess weight. One of the leading causes of knee pain or injury is extra pressure on the patella, which can lead to ligament problems. Losing weight will take some of the pressure off your knees and help make it easier for your muscles, tendons, and ligaments to cushion your joints.

There are also some ways that you can modify your lifestyle that may help reduce pain or injury-related consequences. Wearing good-quality athletic shoes with a low heel or wedge can help distribute the load on your feet more evenly. It’s also essential to have proper footwear for each activity, as this will protect against unnecessary strain on the part of the body.

Here are some other tips for preventing knee injuries from excess weight:

  • Be aware of your body weight and how it might affect you.
  • Do not lift weights that are too heavy for you or do not have a spotter on hand if you cannot lift them safely. 
  • If you need help standing up from a chair, use a handrail or furniture instead of pulling yourself up with just your arms (which can place additional pressure on your knees).

Obesity is a serious health concern that can have many physical and psychological effects, one of which is the likelihood of developing knee injuries. Thankfully, if you are obese or at a higher risk of having an injury, there are many ways to prevent them before they happen.

CLICK HERE to watch a YouTube video about Knee Pain, Diet, and Cartilage

Rick Kaselj[email protected]

Registered Kinesiologist Specializing in Injury Rehabilitation

Surrey, BC, Canada

Jumper’s Knee Solution