Comparative Analysis of the Immediate Post-operative Outcomes between Conventional and Fully Automatic Robotic-assisted Total Knee Arthroplasty

Background: Different techniques employed during conventional and robotic assisted Total Knee Arthroplasty may lead to variation in the immediate post-operative outcomes. Primary objective of the study was to evaluate the differences in the post-operative pain, analgesics use and length of stay between the RA-TKA and C-TKA. Secondary objective was to study the patient reported outcome measures at six months post TKA. Materials & Methods: It is a retrospective review of two cohort of patients (C -TKA and RA-TKA) who were operated between January to April 2022. Patients were given the option between C-TKA and RA- TKA. Sample size was estimated to be 28 patients in each group with α error of 0.05 and power of study being 80%. An independent observer analyzed the post-operative parameters like analgesic use, length of stay, VAS score and Oxford Knee Score at 6 months post TKA. Results: 30 patients in two cohorts were studied. There was no statistically significant difference between the two cohorts as regards the pre-operative patient characteristics. RA- TKA group had a shorter hospital stay (days) than the C-TKA group (3.24±0.50 and 4.07± 0.52, P <0.0001). Pain score (VAS score) was lower in RA -TKA than C-TKA cohort (POD1 5.23 ± 0.50 and 5.93 ± 0.52 POD2 4.40 ± 0.56 and 5.03 ± 0.49, p value <0.0001). R- TKA patients required significantly lower morphine milligram equivalent and NSAIDS than the C-TKA patients (p =0.0005 and p <0.001 respectively). The OKS at 6 months was lower in C-TKA than RA-TKA (32.5± 2.3 C-TKA vs. 33.8±1.5 RA-TKA, p value 0.0120). Conclusions: RA,-TKA cohort showed significant early advantages like decreased post-operative analgesia usage, shorter length of stay and lower pain scores on day 1 and 2 than the C TKA group. The OKS at 6 months was slightly better in RA-TKA vs. C-TKA. Keywords: Robotic-assisted total knee arthroplasty, Conventional total knee arthroplasty, Visual analog scale score, Analgesic.