Direct anterior approach with conventional instruments versus robotic posterolateral approach in elective total hip replacement for primary osteoarthritis: a case–control study

Abstract Background The purpose of this study is to compare peri-operative and short-term outcomes in patients who underwent elective total hip replacement (THA) for primary osteoarthritis (OA) with direct anterior approach (DAA) versus a pair-matched cohort of patients who underwent robotic-assisted THA with posterolateral approach. Materials and methods Data from consecutive patients who underwent elective hip replacement from 2021 to 2023 for primary OA were retrospectively retrieved and divided into two groups: the DAA group, who underwent THA with the DAA approach using conventional instruments, and the robotic posterolateral (R-PL group), who underwent robot arm-assisted THA with the posterolateral approach. Comparative assessed outcomes were: operative time, radiographical implant positioning, intake of rescue analgesics, blood loss, transfusion rate, leg length discrepancy and functional outcomes (Harris hip score and forgotten joint score). Results A total of 100 pair-matched patients were retrieved with a mean age of 66.7 ± 10.7 (range: 32–85) years and a mean follow-up of 12.8 ± 3.6 (range: 7–24) months. No differences in patients’ characteristics were detected. Patients in the R-PL group required less rescue tramadol (p > 0.001), ketorolac (p = 0.028) and acetaminophen (p