Robotic-assisted total knee arthroplasty in patients with moderate-to-severe coronal deformities: A systematic review

Background: Patients with moderate-to-severe varus or valgus deformities present with unique considerations. Therefore, this systematic review aims to evaluate the effectiveness of robotic-assisted total knee arthroplasty (RA-TKA) in addressing moderate-to-severe coronal plane deformities. Methods: MEDLINE, Embase, and Web of Science were searched from inception to January 4, 2025, for single-arm or comparative studies assessing the efficacy of robotic-assisted total knee arthroplasty (RA-TKA) in patients with moderate-to-severe coronal plane deformities undergoing primary surgery. Primary outcome included patient-reported outcomes (PROs), radiographic outcomes, operative times, and complication rates. Results: Eight studies (1274 knees) were included in this study. Of 1244 knees (97.6%) replaced with RA-TKA, 599 presented with pre-operative varus deformity group (47.0%), 82 with valgus deformity group (6.4%), and 563 with minimal to no preoperative deformity (44.2%) used as a control. The remaining 30 patients were in a conventional technique (C-TKA) control group (2.4%). PROs at 1-year postoperatively and beyond were comparable across both varus and valgus knees, and their respective comparator groups. Only one study reported a significant difference in radiographic outlier between RA-TKA and C-TKA, in favor of the former. Operative times were conflicting when comparing RA-TKA versus C-TKA. Limited studies demonstrated no difference in complication rates. Conclusion: RA-TKA reliably attains target radiographic alignment with favorable patient reported outcomes. Several methodological concerns have been highlighted to aid in the development of future studies including the standardization of moderate-to-severe deformity, reporting on associated soft-tissue releases as well as minimization of heterogenous implant use within studies. Loe: IV.