Bariatric surgery is an operational procedure that includes making changes in the digestive system to help the patient lose weight. The effects of bariatric surgery on the fracture risk and fracture patients are not clearly evaluated. This study aims to examine the risk of fracture after bariatric surgery.

This retrospective nested case-control study included a total of 12,676 patients who underwent bariatric surgery. In addition, 32,028 obese and 126,760 non-obese controls matched by age and sex were also included. The primary outcomes of the study were the incidence and sites of fracture in patients who had undergone bariatric surgery.

Before surgery, patients undergoing bariatric surgery were at a 10.5% risk of fracture, compared with 8.1% obese and 2.4% of non-obese controls. At a mean 4.4 years after surgery, patients who underwent bariatric surgery were at the highest risk of surgery (4.1%), compared with obese (2.7%) and non-obese (2.4%) controls. The postoperative adjusted relative fracture risk was 1.38 between the bariatric group and obese controls and 1.44 between the bariatric group and non-obese controls. The most common sites for fracture after surgery were lower limb, upper limb, clinical spine, and femur.

The research concluded that patients undergoing bariatric surgery were at a higher risk of site-specific fracture than obese and non-obese controls.