The decision to undergo hip replacement surgery is often a tough decision to make for any individual. However, the challenges are amplified for people who are overweight, as most doctors recommend the patient lose excessive weight prior to the procedure.
This can often be overwhelming to the patient considering the physical challenges that come with being overweight. These issues are compounded by the tremendous amount of pain caused by the injury that necessitated hip replacement surgery in the first place.
While it can be disheartening to hear these words from the surgeon, the rationale behind their recommendations still seems sound. A person undergoing hip replacement at 350 pounds may have a different experience than those in lower-weight classes. But should this preclude you from having hip replacement surgery? In terms of limits, what is the maximum body mass index (BMI) for hip replacement?
Let’s delve into the relationship between BMI and hip replacement surgery to find out.
The Impact of Weight on the Knees and Hips
The legs’ joints carry the body’s weight in every activity. Whether it’s standing, walking, or running, these joints carry the burden of the body’s weight daily. However, due to the body’s anatomy, the burden placed on the knee and hip joints is amplified, which equates to as much as seven times your total weight. This puts enormous pressure on the knees and hips, which increases further the more you weigh.
Extra weight places an even more significant burden on your joints and can lead to inflammation and pain. This translates to a higher exerted pressure on the knees per pound of weight gained, which increases the risk of knee problems the higher your weight becomes. This is one of the reasons why heavier people tend to require total hip and knee replacements more than people at lower weight classes.
Maximum BMI For Hip Replacement
The body mass index (BMI) is a screening tool used by medical practitioners to estimate body fat. This is calculated using the person’s weight in kilograms (kg) divided by the square of the height in meters (m2).
Generally, the BMI correlates to body fat content and is used to classify people in specific weight classes:
- Underweight: Less than 18.5
- Optimal Range: 18.5 to 24.9
- Overweight: 25 to 29.9
- Class I Obesity: 30 to 34.9
- Class II Obesity: 35 to 39.9
- Class III Obesity: More than 40
The BMI may be inaccurate for athletes and bodybuilders with plenty of muscle mass. However, the impact of the weight remains the same, increasing the amount of pressure on the knees per pound of mass gained, regardless of whether it came from fat or the muscles.
In the past, people who weighed more than 180 to 200 lbs were not considered acceptable candidates for hip replacement surgery. Many of these patients were required to lose at least 40 lbs before they were allowed to undergo surgery.
But with advancements in medical technology and as new research has come to light, the same class of patients is now being cleared for surgery, and acceptable weight ranges have been created.
As for the maximum BMI for hip replacement, the current standard lies at 40. Anyone exceeding a BMI of 40 (Obese Class III) is not considered an ideal candidate for surgery and is not recommended to undergo hip replacement.
Obesity and Hip Replacement Surgery
The advent of non-cemented load-bearing hip implants and improved surfaces and designs for replacement hips and knees have enabled heavier patients to enjoy effective pain relief after surgery and increased activity levels after hip replacement
One 2017 study investigated the risks and benefits of hip replacement on the obese by studying and comparing pain and function before surgery until six months post-surgery. Twenty-five percent of those in the study were among the most obese and were found to have more pain and poorer function before surgery than those in lower weight classes. Meanwhile, the amount of functional gain and pain relief was more substantial in obese individuals six months after surgery, when compared with pain levels and functionality regained being similar among all other weight groups.
The study’s authors concluded that obesity should not be a deterrent to undergoing total hip replacement to experience relief from symptoms. However, the study was not able to formally examine the higher potential for complications among the obese, which must also be considered.
What to Expect After Hip Replacement Surgery
As mentioned above, a hip replacement at 350 pounds is a different experience altogether versus a hip replacement at lower weight classes. This is due to the fact that obese people have a higher risk of experiencing post-surgical complications, such as blood clots, infections, scar tissue development, and poor motion in the joint.
Expected Outcomes Post-Surgery
- While most patients are ready for discharge to continue their recovery at home, obese patients are more likely to stay for an extended period at the hospital for additional care and monitoring after outpatient surgery.
- The average length of stay for obese patients at the hospital post-surgery is longer than for non-obese patients and obese patients may need to go to a skilled nursing rehabilitation center to assist in their recovery.
- After being discharged from the hospital, obese patients are also more likely to return to the hospital for additional care, emergency care, or readmission.
- Obese patients may also be prescribed a different set of or additional medications in order to treat other underlying conditions.
Potential Complications
Countless studies have shown that obesity increases a person’s risk of a medical or surgical complication after surgery – and hip replacement is no exception. While during and after the surgery, the patient may experience such problems as non-healing wounds and infections. These complications may require additional surgeries, resulting in the loss of a limb or life.
In many cases, obese patients undergoing hip replacement may already have medical comorbidities that amplify the underlying risks of surgical hip replacement. These may include such conditions as cardiovascular disease, malnutrition, metabolic syndrome, diabetes, or obstructive sleep apnea.
For these reasons, performing a thorough medical assessment of a patient whose BMI is above average is even more critical. Some surgeons, healthcare facilities, and insurance companies have even adopted BMI cutoffs to limit the risk of complications for patients with higher BMIs. These cutoffs are generally between BMIs of 35 and 40, with 40 being the absolute maximum BMI for hip replacement.
Hip Replacement Surgery at the American Hip Institute
Weight is a major concern when undergoing hip replacement surgery, as the potential for complications increases with the more you weigh. While technology has come a long way, surgeons still recommend adjusting your weight and improving your overall health before undergoing surgery to avoid complications.
At the American Hip Institute, we are dedicated to providing the best care possible while providing relief from pain experienced through various hip conditions. Our specialists will work closely with you to develop the best treatment plan that eases your pain while ensuring the best possible outcome.
If you are experiencing pain and want to undergo hip replacement surgery but are concerned about your weight, schedule a consultation with us today to learn about your options
