Outpatient Versus Inpatient Total Hip and Knee Arthroplasty in Morbidly Obese Patients.

Background: Morbidly obese patients undergoing total joint arthroplasty (TJA) face increased postoperative complications, yet studies assessing the safety of this surgery in the outpatient setting for this population are lacking. This study aimed to fill this gap by assessing the safety and benefits of outpatient TJA in morbidly obese patients.

Methods: This study is a retrospective review of a commercial claims database. Based on the setting of the procedure, the patients were divided into four groups as follows: inpatient-TKA (total knee arthroplasty), outpatient-TKA, inpatient-THA (total hip arthroplasty), and outpatient-THA. The two TKA groups were matched based on age, sex, and the Charlson Comorbidity Index. The THA groups were matched similarly. The 30- and 90-day medical and surgical complications were compared between these groups. There were 5,500 patients included in each of the outpatient and inpatient TKA groups and 1,550 in each of the outpatient and inpatient THA groups.

Results: Patients undergoing inpatient TKA had higher rates of pulmonary embolism, urinary tract infection, transfusions, intensive care unit admissions, emergency department visits, readmissions at 30 days, surgical site infections, periprosthetic joint infection, prosthetic dislocations, and costs. As for the inpatient THA group, they had higher rates of pulmonary embolism, urinary tract infection, transfusions, intensive care unit admissions, emergency department visits, and costs.

Conclusions: It is well-established that morbidly obese patients undergoing TJA have higher complication rates than normal-weight patients, and patients should be counseled before arthroplasty. This study highlights the safety and benefits of outpatient TJA in morbidly obese patients. However, one should note that this was done using an insurance database, in which results may differ if it was done in a public and lower socioeconomic setting. Therefore, future prospective studies are needed to confirm the findings before implementing outpatient TJA in morbidly obese patients.