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Robotic arm-assisted total knee arthroplasty is associated with improved surgical and postoperative outcomes compared
Mei Lin Tay1,2, Kohei Kawaguchi2,3, Scott Matthew Bolam1,2
1Department of Orthopaedic Surgery, North Shore Hospital, Auckland, New Zealand.
Aims:
Computer-assisted technology has greater surgical accuracy for total knee arthroplasty (TKA); however, it is unclear if this is associated with better patient outcomes. There is a paucity of data comparing robotic arm-assisted TKA (RA-TKA) and computer-navigated TKA (nav-TKA). The aim of this study was to compare mid-term outcomes of image-based semiactive RA-TKA with imageless nav-TKA in a large patient cohort.
Methods:
Patient characteristics, surgical variables, complications, and patient-reported outcomes were recorded for 1,434 primary TKAs (388 RA-TKAs; 1,046 nav-TKAs) performed between November 2019 and October 2023 at a large tertiary hospital. Data were analyzed using Fisher's exact or Mann-Whitney U tests. Analyses were performed for cohorts matched for baseline demographics and follow-up time.
Results:
Compared to nav-TKA, matched RA-TKA cases had a shorter operating time (86.8 mins (SD 18.5) vs 93.3 mins (SD 23.6); p < 0.001), shorter length of stay (3.1 days (SD 1.4) vs 3.4 days (SD 1.6); p < 0.001), and fewer manipulations under anaesthesia (15 (4%) vs 29 (8%); p = 0.042). There were similar frequencies of inpatient complications (15 (4%) vs 22 (6%); p = 0.312), emergency department (ED) presentations (32 (8%) vs 41 (11%); p = 0.325), and revisions (five (1%) vs two (0.5%); p = 0.451) for RA-TKA and nav-TKA, respectively. At two years, RA-TKA patients reported higher Oxford Knee Score (41.2 (SD 6.7) vs 39.3 (SD 7.7); p = 0.003), EuroQol five-dimension questionnaire index (EQ-5D) (0.88 (SD 0.16) vs 0.82 (SD 0.20); p = 0.010), and EQ-5D Health (80.6 (SD 15.5) vs 77.2 (SD 16.9); p = 0.035), and lower levels of pain (11.0 (SD 18.2) vs 15.3 (SD 20.9); p < 0.001). Fewer RA-TKA patients were dissatisfied at six months (3% vs 7%; p = 0.034) and two years (3% vs 9%; p = 0.019).
Conclusion:
The findings suggest that image-based semiactive robotic assistance for TKA has benefits over imageless computer-assisted navigation, including shorter hospital length of stay, fewer MUAs, and improved mid-term patient-reported outcomes, but similar complications and ED presentations. Cost analysis showed that RA-TKA can have cost benefits at high-volume centres, however this needs to be weighed against the high initial cost of RA-TKA systems.
