Otto Aufranc Award: A Multicenter, Randomized Study of Outpatient versus Inpatient Total Hip Arthroplasty

Background Length of stay after total hip arthroplasty (THA) has decreased over the last two decades. However, published studies that have examined same-day and early discharge protocols after THA have been done in highly selected patient groups operated on by senior surgeons in a nonrandomized fashion without control subjects.

Questions/purposes The purpose of this study was to evaluate and compare patients undergoing THA who are discharged on the same day as the surgery (“outpatient,” less than 12-hour stay) with those who are discharged after an overnight hospital stay (“inpatient”) with regard to the following outcomes: (1) postoperative pain; (2) perioperative complications and healthcare provider visits (readmission, emergency department or physician office); and (3) relative work effort for the surgeon’s office staff.

Methods A prospective, randomized study was conducted at two high-volume adult reconstruction centers between July 2014 and September 2015. Patients who were younger than 75 years of age at surgery, who could ambulate without a walker, who were not on chronic opioids, and whose body mass index was less than 40 kg/m²were invited to participate. All patients had a primary THA performed by the direct anterior approach with spinal anesthesia at a hospital facility. Study data were evaluated using an intention-to-treat analysis. A total of 220 patients participated, of whom 112 were randomized to the outpatient group and 108 were randomized to the inpatient group. Of the 112 patients randomized to outpatient surgery, 85 (76%) were discharged as planned. Of the remaining 27 patients, 26 were discharged after one night in the hospital and one was discharged after two nights. Of the 108 patients randomized to inpatient surgery with an overnight hospital stay, 81 (75%) were discharged as planned. Of the remaining 27 patients, 18 met the discharge criteria on the day of their surgery and elected to leave the same day, whereas nine patients stayed two or more nights.

Results On the day of surgery, there was no difference in visual analog scale (VAS) pain among patients who were randomized to discharge on the same day and those who were randomized to remain in the hospital overnight (outpatient 2.8 ± 2.5, inpatient 3.3 ± 2.3, mean difference −0.5, 95% confidence interval [CI], −1.1 to 0.1, p = 0.12). On the first day after surgery, outpatients had higher VAS pain (at home) than inpatients (3.7 ± 2.3 versus 2.8 ± 2.1, mean difference 0.9, 95% CI, 0.3-1.5, p = 0.005). With the numbers available, there was no difference in the number of reoperations, hospital readmissions without reoperation, emergency department visits without hospital readmission, or acute office visits. At 4-week followup, there was no difference in the number of phone calls and emails with the surgeon’s office (outpatient: 2.4 ± 1.9, inpatient: 2.4 ± 2.2, mean difference 0, 95% CI, −0.5 to 0.6, p = 0.94).

Conclusions Outpatient THA can be implemented in a defined patient population without requiring additional work for the surgeon’s office. Because 24% (27 of 112) of patients planning to have outpatient surgery were not able to be discharged the same day, facilities to accommodate an overnight stay should be available.

Level of Evidence Level I, therapeutic study.