Worthwhile Bariatric Surgery in People with Knee Osteoarthritis
TABLE OF CONTENTS
Introduction
The treatment of knee osteoarthritis involves losing weight. Unfortunately, doctors are becoming increasingly aware that standard treatment—such as NSAIDs, corticosteroid injections, and physical therapy—is frequently insufficient to reduce pain. Additionally, many healthcare professionals hesitate to use opioids as monotherapy. A knee replacement may be the only option.
To reduce risks and complications, weight reduction is advised before total knee replacement (TKR). These include extended hospital stays and recovery following surgery, greater anesthetic expenses, and residual effects.
The greatest risk factor for developing knee osteoarthritis (OA) is still obesity. Due to weight reduction and decreased mechanical stress, studies have shown improvements in knee pain and function following bariatric surgery; nevertheless, other studies have discovered greater rates of total knee arthroplasty (TKA) in that patient population.
Knee Anatomy
The modified hinge joint in the knee is subjected to significant contact and shear pressures during walking. The knee can be observed in three alignments:
Neutral
Valgus (knock-knee)
Varus (bow-legged)
Degenerative alterations to the knee’s three compartments—medial, lateral, and patellofemoral—can drastically modify pressure distribution and wear patterns, aggravating or changing the knee’s current posture.
When walking on a flat surface, the force on the knees with every step is around 4 times the body’s weight.
When going down an incline, the force increases to about 8 times the body’s weight.
The average bariatric patient experiences baseline pressures equivalent to downward walking and significantly larger forces with increased activity.
These parts may get damaged or degenerate, resulting in knee discomfort. The degradation of cartilage (osteoarthritis), with variable pain and functional impairment, can be caused by prior injury and aging.
Notably, obesity increases the risk of osteoarthritis development in individuals with baseline or valgus alignment but not in those with varus alignment.
Value of Bariatric Surgery
For individuals with knee osteoarthritis and class II or III obesity, researchers compared the effectiveness of gastric bypass surgery (RYGB) to standard therapy. Their research was published in Arthritis Care & Research.
With a higher lifetime cost of $7209 (~₹5,91,138), researchers found that RYGB increased quality-adjusted life expectancy by 1.36 years.
In patients with BMI ≥40 kg/m², usual care combined with LSG had less benefit than RYGB, though it still showed good value in patients with BMI 38–41 kg/m².
Both treatments increased the rate of TKR while decreasing opioid use.
RYGB was shown to increase quality-adjusted life expectancy by 31%.
The initial decrease in knee pain was accompanied by a 3.7% yearly likelihood of pain recurrence in the following years.
Conclusion of Research:
Bariatric surgery for greater weight reduction may benefit people with class II and III obesity who have knee osteoarthritis.
This weight reduction will probably result in more TKR cases.
Patients who fail to respond to standard therapy and struggle with weight loss should be referred to bariatric surgery clinics for evaluation.
Conclusion
Long-lasting weight loss can be achieved through gastric bypass and other bariatric procedures. The type of surgery and subsequent lifestyle changes determine the extent of weight loss. Within two years, patients may lose 50% or more of their excess weight.
Knee function, especially for sports-related activities, improved significantly after surgically induced rapid weight loss.
However, knee discomfort often remained unchanged.
This may be linked to leaner weight loss combined with high-impact knee activities.
Key Point: Customized exercise regimens for bariatric surgery patients may help reduce long-term knee replacement needs and improve overall symptoms.
