Robotic-assisted total knee arthroplasty improves accuracy and precision compared to conventional techniques

Abstract

Aims Robotic-assisted total knee arthroplasty (RA-TKA) is theoretically more accurate for component positioning than TKA performed with mechanical instruments (M-TKA). Furthermore, the ability to incorporate soft-tissue laxity data into the plan prior to bone resection should reduce variability between the planned polyethylene thickness and the final implanted polyethylene. The purpose of this study was to compare accuracy to plan for component positioning and precision, as demonstrated by deviation from plan for polyethylene insert thickness in measured-resection RA-TKA versus M-TKA. Methods A total of 220 consecutive primary TKAs between May 2016 and November 2018, performed by a single surgeon, were reviewed. Planned coronal plane component alignment and overall limb alignment were all 0° to the mechanical axis; tibial posterior slope was 2°; and polyethylene thickness was 9 mm. For RA-TKA, individual component position was adjusted to assist gap-balancing but planned coronal plane alignment for the femoral and tibial components and overall limb alignment remained 0 ± 3°; planned tibial posterior slope was 1.5°. Mean deviations from plan for each parameter were compared between groups for positioning and size and outliers were assessed. Results In all, 103 M-TKAs and 96 RA-TKAs were included. In RA-TKA versus M-TKA, respectively: mean femoral positioning (0.9° (SD 1.2°) vs 1.7° (SD 1.1°)), mean tibial positioning (0.3° (SD 0.9°) vs 1.3° (SD 1.0°)), mean posterior tibial slope (-0.3° (SD 1.3°) vs 1.7° (SD 1.1°)), and mean mechanical axis limb alignment (1.0° (SD 1.7°) vs 2.7° (SD 1.9°)) all deviated significantly less from the plan (all p < 0.001); significantly fewer knees required a distal femoral recut (10 (10%) vs 22 (22%), p = 0.033); and deviation from planned polyethylene thickness was significantly less (1.4 mm (SD 1.6) vs 2.7 mm (SD 2.2), p < 0.001). Conclusion RA-TKA is significantly more accurate and precise in planning both component positioning and final polyethylene insert thickness. Future studies should investigate whether this increased accuracy and precision has an impact on clinical outcomes. The greater accuracy and reproducibility of RA-TKA may be important as precise new goals for component positioning are developed and can be further individualized to the patient. Cite this article: Bone Joint J 2021;103-B(6 Supple A):74–80.

Patient Interest in Robotic Total Joint Arthroplasty Is Exponential: A 10-Year Google Trends Analysis

“…As such, there have been several previous investigations into implant positioning, limb length and alignment, learning curve, postoperative outcomes, and cost-effectiveness with robotic arthroplasty with an attempt to demonstrate advantages. When compared to conventional jig-based TKA, robotic knee arthroplasty has been associated with increased accuracy, improved implant positioning, and a reduction in outliers [ 3 , [14] , [15] , [16] ]. However, this has not translated into clinical benefits for patients at midterm to long-term follow-up [ 17 , 18 ].…”

“…Robotics in total joint arthroplasty (TJA) have several proposed benefits for surgeons and patients. Notably, robotic arm-assisted TJA have been shown to be more accurate than manual on radiographic evaluation of component position [ 3 , 4 ]. However, the evidence is variable, and robotics has yet to translate to improvements in clinical outcomes [ 5 , 6 ].…”

Comparison of serum inflammatory indicators and radiographic results in MAKO robotic-assisted versus conventional total knee arthroplasty for knee osteoarthritis: a retrospective study of Chinese patients

“…Whether robotic assistance has a more positive impact on early functional recovery after TKA remains controversial. RA-TKA has been widely reported to improve precision, provide better prosthesis position and lower extremity force lines, and obtain better imaging and functional outcomes than conventional surgery [ 1 – 3 ]. However, some studies have also concluded that there is no major difference in postoperative function and pain scores between robot-assisted and conventional manual total knee arthroplasty (CM-TKA) [ 4 – 6 ].…”

A Coronal Landmark for Tibial Component Positioning With Anatomical Alignment in Total Knee Arthroplasty: A Radiological and Clinical Study

“…In addition to robots, common assistive technologies include computer navigation and patient-specific cutting guides. There has been abundant evidence that computer navigation ( 35 , 36 ) and robots ( 37 , 38 ) can produce better precision and prosthesis alignment than conventional instrumentation but limited evidence that this translates into better long-term clinical outcomes. Patient-specific cutting guides also require customization.…”