Impact of Bariatric Surgery on Inpatient Complication, Cost, and Length of Stay Following Total Hip or Knee Arthroplasty

Background: Morbid obesity is an important risk factor for arthroplasty and also closely associated with worse postoperative outcomes. Bariatric surgery is effective in losing weight and decreasing comorbidities associated with obesity. However, no study had demonstrated the influence of bariatric surgery on the outcome of arthroplasty in a large population. Methods: We used 2006-2014 discharge records from the Nationwide Inpatient Sample, and identified study population and inpatient complications by International Classification of Diseases, 9th Revision, Clinical Modification diagnosis/procedure codes. Propensity score analysis was used to match total hip arthroplasty (THA) or total knee arthroplasty (TKA) patients with morbid obesity and THA or TKA patients with bariatric surgery. Results: Proportion of morbid obesity in both TKA and THA patients demonstrated a rising trend, while proportion of bariatric surgery in morbidly obese TKA and THA patients remains steady after 2007. For THA patients, there was fewer pulmonary embolism, more blood transfusion and anemia, and shorter length of stay in bariatric surgery group. For TKA patients, bariatric surgery group had a lower risk of pulmonary embolism, respiratory complications, death, and shorter length of stay, but bariatric surgery group had a higher risk of blood transfusion and anemia. Conclusion: There is evidence that bariatric surgery prior to arthroplasty, especially THA, appears to reduce rates of pulmonary complications and length of stay. But anemia and blood transfusion seem to be more common in patients with prior bariatric surgery. (C) 2019 Published by Elsevier Inc.