Patient-reported outcomes are comparable between imageless robotic-assisted and computer-navigated total knee arthroplasty: A retrospective cohort study

The benefits of computer-navigated total knee arthroplasty (CN-TKA) are well established, and although early studies have demonstrated some benefits of robotic-assisted total knee arthroplasty (RA-TKA), there is limited evidence on the clinical and patient-reported outcome measures (PROMs) directly compared to CN-TKA. As RA-TKA continues to gain popularity, it is important to compare outcomes with the more established technique to justify its use. This study compares PROMs for imageless RA-TKA versus CN-TKA, and between RA-TKA performed with either ROSA or CORI. This was a retrospective study of prospectively collected data of patients who underwent primary TKA for osteoarthritis (OA). The study included consecutive surgeries between December 2021 and April 2023, utilising imageless RA-TKA (ROSA or CORI) or CN-TKA. PROMs were obtained preoperatively, at 3 months, and at 12 months, including the Oxford knee score (OKS), Forgotten Joint Score (FJS), Veterans Rand 12-item mental and physical health survey (VR-12), pain (visual analogue scale [VAS]) and patient satisfaction scores. A total of 399 patients were recruited: 212 underwent RA-TKA (CORI: n = 104; ROSA: n = 108), and 187 underwent CN-TKA. There were no significant differences between groups at baseline. At 12 months, patient satisfaction with medical care favoured CN-TKA (adjusted mean difference: -3.94; 95% CI: -7.44, -0.45). Between ROSA and CORI systems, patients' subjective knee normality score favoured CORI (adjusted mean difference: -8.44; 95% CI: -16.0, -0.90). No other meaningful differences were observed in either comparison. This study showed no difference in PROMS (OKS and FJS) between CN-TKA and RA-TKA; however, a modest benefit was seen in patient satisfaction with medical care favouring CN-TKA. Similarly, only a modest difference was identified between ROSA and CORI, with knee joint normality favouring the CORI system. These findings demonstrate no clear short-term benefit for well-established navigation surgeons to change to robotic techniques, although further investigations would be valuable. Level III.