Imageless handheld robotic-assisted total knee arthroplasty showed better clinical outcomes than conventional total knee arthroplasty: A randomized controlled trial with preliminary results at 1-year follow up

Background: Robotic-assisted total knee arthroplasty (RATKA) has been shown to achieve more accurate functional implant alignment than conventional instrumented TKA (CTKA). The aim of this randomized controlled trial was to assess differences in operative, clinical and functional outcome of RATKA compared with CTKA. Methods: A total of 180 patients with osteoarthritis were included and randomized. Preoperative and 3- and 12-months postoperative patient-reported outcome measures (PROMs) and rate of serious adverse events (SAEs), requirement for ligament releases and implant sizes were compared. Results: The preoperative baseline variables were not statistically different between RATKA and CTKA groups thus they were well matched. At 12 months follow up, RATKA had significantly better Oxford Knee Score (42.4 ± 5.4 vs. 38.7 ± 7.2, P < 0.001), KSS^function (81.2 ± 12.3 vs. 72.7 ± 15.1, P < 0.001), KSS^satisfaction (34.9 ± 5.2 vs. 31.2 ± 7.9, P < 0.001), EQ5D^index (0.883 ± 0.141 vs. 0.833 ± 0.144, P < 0.001), VAS pain^day (10.5 ± 12.5 vs. 21.5 ± 19.4, P < 0.001), and VAS pain^night (8.1 ± 11.3 vs. 18.9 ± 19.5, P = 0.029), Patient satisfaction (93.2 ± 8.3 vs. 79.8 ± 20.3, P < 0.001) and FJS-12 (73.2 ± 23.3 vs. 53.6 ± 29.0, P < 0.001) as compared with the CTKA group. The proportion of patients in the RATKA group requiring ligament release was lower (six (7%) vs. 45 (50%), P < 0.001) and those requiring a polyethylene thickness = 10 (55 (62%) vs. 36 (40%), P < 0.004). There was no difference in the rate of SAEs between the two groups. Conclusion: This randomized controlled trial found significantly higher PROMs in patients undergoing RATKA with no difference in SAEs as compared with CTKA. RATKA technology also showed reduced requirement for ligament release and smaller polyethylene sizes.