Kulkarni and colleagues47 compared the rates of hip and knee arthroplasty complications in patients who were obese before bariatric surgery and patients who were still obese after bariatric surgery. Gastroplasty and bypass patients were included. Data on superficial wound infections were excluded; however, the bariatric surgery group’s deep wound infection rate was 3.5 times lower, and its 30-day readmission rate was 7 times lower. There was no difference in dislocation and hip revision rates at 1 year. Although 1 patient in the bariatric surgery group died of an unknown cause 9 days after surgery, Kulkarni and colleagues47 concluded it is safer to operate on obese patients after versus before bariatric surgery. However, their study did not include mean BMI, so no conclusion can be drawn about the risk of operating on patients who were still obese after bariatric surgery.
Studies of weight loss in primary TJA patients have had conflicting findings.48 Trofa and colleagues49 reported that 15 patients who underwent arthroplasty a mean of 42.4 months after bariatric surgery lost 27.9% more of their original BMI compared with patients who underwent bariatric surgery but not arthroplasty. This relationship between arthroplasty and weight loss was strongest in patients who underwent knee arthroplasty, with an average of 43.9% more BMI lost compared to patients who did not undergo TKA. There was no significant change in BMI in patients who underwent THA and bariatric surgery compared with patients who underwent bariatric surgery but not THA.
Parvizi and colleagues50 assessed the results of 20 arthroplasties (8 THAs, 12 TKAs) performed in 14 patients a mean of 23 months after bariatric surgery (2 gastroplasties, 12 bypass surgeries). Mean BMI was 29 kg/m2. At final follow-up, 1 patient required revision THA for aseptic loosening, but all the others showed no evidence of radiographic loosening or wear. One patient had a superficial wound infection, and 1 had a deep wound infection. Parvizi and colleagues50 reported that arthroplasty after bariatric surgery is a viable option and is preferable to operating on morbidly obese patients.
Summary
Orthopedic surgeons are increasingly performing elective hip and knee arthroplasties on patients who have undergone bariatric surgery. Although bariatric surgery may alleviate some of the complications associated with surgery on morbidly obese patients, it should be approached with caution. Studies have shown that bariatric surgery patients are at increased risk for wound-healing and other complications, often caused by unrecognized preoperative nutrient deficiencies. In addition, patients are often unable to tolerate commonly used medications. The exact timing of bariatric surgery relative to elective orthopedic procedures is unclear. Surgeons should perform a preoperative evaluation based on type of bariatric surgery in order to reduce the likelihood of adverse events. Such preemptive therapy may improve the short- and long-term results of major reconstructive surgery. Further research is needed to determine the true effect of bariatric surgery on orthopedic procedures.
