Recent Bariatric Surgery Linked to More Complications After Joint Arthroplasty

By Scott Baltic

December 04, 2019

NEW YORK (Reuters Health) - Rather than benefitting from bariatric surgery, obese patients who undergo such a procedure less than two years before total joint arthroplasty (TJA) are more likely to experience postoperative complications, according to a new study.

Immediate hospital costs were also higher in those with a history of bariatric surgery, as was the likelihood of postoperative transfusion, researchers report in the Journal of the American Academy of Orthopaedic Surgeons, online September 16.

"Our study brings into focus the fact that although the rate of bariatric surgery has been rapidly rising over the last few years, we may not be seeing as many of the presumed benefits in total joint replacement," Dr. Kirk Campbell of NYU Langone Health in New York City told Reuters Health by email.

He and his colleagues analyzed data on more than 343,000 patients 18 years or older who underwent TJA in New York State from 2005 to 2014. They split the population into three groups: Group 1 (mean age 56) consisted of obese patients (BMI, 30 or greater) who underwent TJA within two years of bariatric surgery; group 2 (mean age, 62) of obese patients who had not undergone bariatric surgery two years or less before TJA; and group 3 (mean age, 66) of non-obese patients who did not undergo bariatric surgery.

Patients in group 1 were significantly more likely than those in group 2 to experience one or more 90-day postoperative complications (41% vs. 36%, P=0.001) and have postoperative transfusions (26% vs. 22%, P=0.001).

Total hospital charges and costs were $18,869 in group 1 versus $17,843 in group 2 (P<0.001).

No statistically significant differences were found between groups 1 and 2 in home discharge rates, length of hospital stay, all-cause mortality, deep vein thrombosis, pulmonary embolism, or infection rates.

Group-1 patients had significantly shorter mean hospital stays and significantly lower rates of transfusion and pneumonia compared with group-3 patients, however. The authors speculate that this was driven by group 3's greater mean age.

The study also found that the incidence of bariatric surgery before TJA increased annually in New York State over a 10-year period starting in 2006, as did each procedure separately. Patients between ages 45 and 64 had the highest overall incidence of bariatric surgery before TJA.

Deciding whether an obese patient who needs a total joint replacement should have bariatric surgery before a joint replacement, Dr. Campbell said, is an individual choice that should be made by the patient and their orthopedic surgeon. This study, the researcher added, "offers some objective data to aid in that decision-making process."

Dr. Chad Watts, an orthopedic surgeon at the University of Nevada, in Reno, who was not involved in the study, told Reuters Health by email, "The knee-jerk reaction is that if we send a patient for bariatric surgery and they lose weight, then their complication risk will decrease. However, our studies suggest this might not be the case."

Dr. John Ryan Martin, a hip and knee surgeon at OrthoCarolina, in Charlotte, North Carolina, said that although numerous studies have shown that increasing BMI is tied to worse outcomes following TJA, "Bariatric surgery prior to total joint replacement places patients in a temporary catabolic state and may cause patients to be malnourished if not monitored appropriately."

"Patient optimization should remain an integral part of the preoperative pathway for obese patients undergoing TJA," he told Reuters Health by email.

"I would discuss with patients that we do not have enough evidence to definitively say which approach is safer (having bariatric surgery before or after TJA). I would ensure in either case that all patient risk factors have been optimized, including diabetes, heart disease, smoking status, etc., before proceeding with surgery to try and limit complications," said Dr. Martin, who also was not part of the new study.

Drs. Martin and Watts have collaborated on studies on bariatric surgery and total knee or hip arthroplasty.


J Am Acad Orthop Surg 2019.