Robotic-Assisted Versus Manual Total Hip Arthroplasty Performed for Hip Dysplasia

INTRODUCTION: Developmental dysplasia of the hip (DDH) poses challenges for component positioning during total hip arthroplasty (THA) secondary to abnormal bone morphology, soft-tissue contractures, and hip center migration. The objective of this study was to evaluate the radiographic and clinical outcomes of THA for DDH performed with robotic assistance versus manual (M) technique. METHODS: A retrospective review identified 115 patients with Crowe II to IV dysplasia undergoing primary THA at a single institution from 2016 to 2022. There were 59 (51%) M-THAs and 56 (49%) RA-THAs. The median age was 49 years, the median body mass index was 28, and 94 (82%) patients were women. No difference was seen in Crowe classification between cohorts. The mean follow-up was two years. RESULTS: No difference was observed in mean surgical time between robotic-assisted THA (RA-THA) and manual THA (M-THA) cohorts (118 vs. 135 minutes, P = 0.23). Postoperatively, there was no difference in leg length discrepancy or hip center restoration. The RA-THA cohort had a lower rate of acetabular implant malposition (inclination and/or anteversion; n = 7, 15%) versus the M-THA (n = 16, 40%) cohort ( P = 0.01). There were two (3%) dislocations in the M-THA cohort versus no dislocations in the RA-THA cohort ( P = 0.17). There were three (5%) revision surgeries in the M-THA cohort, including one acetabular revision for recurrent instability, one femoral implant revision for aseptic loosening, and one femoral osteotomy with retrograde intramedullary lengthening nail for residual leg length discrepancy correction. There were no revision surgeries in the RA-THA cohort ( P = 0.09) or component revisions ( P = 0.17). CONCLUSION: In this series of primary THA for DDH, RA-THA was associated with decreased rates of acetabular implant malpositioning. In addition, RA-THA trended toward lower rates of dislocation and revision surgery with equivalent surgical times to M-THA, demonstrating its feasibility and efficacy in primary THA for DDH.