Abstract
Although there are many studies on the alignment advantages when using the robotic
arm–assisted (RAA) system for total knee arthroplasty (TKA), there have been questions
regarding patient-reported outcomes. Therefore, the purpose of this study was to use
this index to compare: (1) total, (2) physical function, and (3) pain scores for manual
versus RAA patients. We compared 53 consecutive RAA to 53 consecutive manual TKAs.
No differences in preoperative scores were found between the cohorts. Patients were
administered a modified Western Ontario and McMaster Universities Osteoarthritis Index
satisfaction survey preoperatively and at 1-year postoperatively. The results were
broken down to: (1) total, (2) physical function, and (3) pain scores. Univariate
analysis with independent samples t-tests was used to compare 1-year postoperative scores. Multivariate models with stepwise
backward linear regression were utilized to evaluate the associations between scores
and surgical technique, age, sex, as well as body mass index (BMI). Statistical analyses
were performed with a p < 0.05 to determine significance. The RAA cohort had significantly improved mean
total (6 ± 6 vs. 9 ± 8 points, p = 0.03) and physical function scores (4 ± 4 vs. 6 ± 5 points, p = 0.02) when compared with the manual cohort. The mean pain score for the RAA cohort
(2 ± 3 points [range, 0–14 points]) was also lower than that for the manual cohort
(3 ± 4 points [range, 0–11 points]) (p = 0.06). On backward linear regression analyses, RAA was found to be significantly
associated with more improved total (β coefficient [β] −0.208, standard error [SE]
1.401, p < 0.05), function (β = 0.216, SE = 0.829, p < 0.05), and pain scores (β −0.181, SE = 0.623, p = 0.063). The RAA technique was found to have the strongest association with improved
scores when compared with age, gender, and BMI. This study suggests that RAA patients
may have short-term improvements at minimum 1-year postoperatively. However, longer
term follow-up with greater sample sizes is needed to further validate these results.
Keywords
robotic-arm-assisted TKA - TKA - new technologies - outcomes
