No Difference in Early Range of Motion Between CORI Robotic-TKA and Conventional-TKA: A Single-Surgeon Series

Despite the increasing use of robotic-assisted total knee arthroplasty (r-TKA), data on functional outcomes remain limited. This study evaluated 6-week range of motion (ROM) outcomes in patients who underwent r-TKA vs conventional TKA (c-TKA) to determine whether robotic assistance improves early postoperative ROM.

A retrospective analysis was conducted on consecutive patients who underwent primary TKA by a single surgeon using r-TKA or c-TKA between 2019 and 2023. Exclusion criteria included simultaneous bilateral, revision, unicompartmental, and posttraumatic conversion arthroplasties. Knee flexion and extension ROM were measured preoperatively and at standardized 2- and 6-week postoperative visits. Manipulation under anesthesia (MUA) rates for postoperative stiffness were also analyzed. Linear mixed models assessed between-group differences in ROM over time, adjusting for race, sex, body mass index, and preoperative knee alignment.

A total of 1124 patients (mean age 65.5 ± 8.7 years) were included, with 729 (64.9%) in the c-TKA cohort and 395 (35.1%) in the r-TKA cohort. Knee extension ROM between the c-TKA and r-TKA groups was not different preoperatively (1.3 ± 6.7 vs 0.8 ± 5.0; P = .209) or 6 weeks postoperatively (1.1 ± 3.6 vs 1.1 ± 2.9; P = .661). Knee flexion ROM between the c-TKA and r-TKA groups was not different preoperatively (114.7 ± 12.0 vs 115.3 ± 11.7; P = .677) or 6 weeks postoperatively (110.8 ± 12.6 vs 112.3 ± 11.6; P = .185). MUA rates were similar between the c-TKA and r-TKA cohorts (2.5% vs 3.0%; P = .359), respectively.

Robotic-assisted TKA demonstrated comparable early postoperative ROM and MUA rates to c-TKA. Future studies should explore long-term ROM outcomes and their correlation with patient-reported outcomes to further guide clinical practice.

III, Retrospective cohort.