The LANCET robotic system improves radiographic alignment and prosthesis positioning in TKA: a multicenter, prospective controlled clinical trial

• LANCET robotics assisted TKA achieves better lower limb mechanical alignment • LANCET robotics assisted TKA achieves higher prosthesis placement compliance compared to conventional manual TKA • LANCET robot assisted knee arthroplasty has more blood loss but little change in hemoglobin concentration • LANCET robot-assisted approach shows comparable clinical outcomes (range of motion, functional scores, pain relief) to conventional surgery We introduced a cost-effective semi-automatic total knee arthroplasty (TKA) robotic system-LANCET RobPath and validate its accuracy and effectiveness through a prospective and multicenter trial. A multicenter prospective controlled single-blind clinical trial was conducted by five joint centers. Patients who underwent TKA were admitted and divided into two groups: robot-assisted group (RA group) and conventional manual group (CM group). Patients’ baseline characteristics, clinical subjective assessment indices, radiographic findings, hemoglobin (Hb) level changes, and operative duration were recorded and analyzed. No adverse events related to machine malfunctions occurred. The mean HKA angles of the two groups were (178.5° ± 2.9°) and (177.3° ± 3.7°), respectively (P=0.014). The HKA offset in the RA group was (2.5° ± 2.1°), while (3.6° ± 2.8°) in the CM group (P=0.006). The compliance rates of the planned prostheses were 86.96% and 73.02%, respectively. Compared with the CM group, the RA group extended the surgical time (149.8 ± 46.0 min vs 97.5 ± 32.3 min, P=0.020). At the end of 3-month follow-up period, there was no significant difference between RA and CM groups when assessed by range of motion, Knee Society Score, Visual Analog Scale. The LANCET robot-assisted knee replacement surgery system has good safety, precise surgical planning and osteotomy, and can obtain better lower limb alignment. This robotic system has the potential to be widely applied in clinical practice.