CT Validation of Intraoperative Implant Position and Knee Alignment as Determined by the MAKO Total Knee Arthroplasty System

Abstract

Robotic-assisted technology in total knee arthroplasty (TKA) aims to increase implantation accuracy, with real-time data being used to estimate intraoperative component alignment. Postoperatively, Perth computed tomography (CT) protocol is a valid measurement technique in determining both femoral and tibial component alignments. The aim of this study was to evaluate the accuracy of intraoperative component alignment by robotic-assisted TKA through CT validation. A total of 33 patients underwent TKA using the MAKO robotic-assisted TKA system. Intraoperative measurements of both femoral and tibial component placements, as well as limb alignment as determined by the MAKO software were recorded. Independent postoperative Perth CT protocol was obtained (n = 29) and compared with intraoperative values. Mean absolute difference between intraoperative and postoperative measurements for the femoral component were 1.17 degrees (1.10) in the coronal plane, 1.79 degrees (1.12) in the sagittal plane, and 1.90 degrees (1.88) in the transverse plane. Mean absolute difference between intraoperative and postoperative measurements for the tibial component were 1.03 degrees (0.76) in the coronal plane and 1.78 degrees (1.20) in the sagittal plane. Mean absolute difference of limb alignment was 1.29 degrees (1.25), with 93.10% of measurements ≤3 degrees of postoperative CT measurements. Overall, intraoperatively measured component alignment as estimated by the MAKO robotic-assisted TKA system is comparable to CT-based measurements.

Personalized alignment in total knee arthroplasty: current concepts

“…Several studies assessed the accuracy and the reproducibility of robotic-assisted surgery [42][43][44][45][46]. Sires and Wilson performed CT scans postoperatively to assess the precision of the image-based robotic-assisted TKA and found that 93% of the surgical measurements were 3°of the CT measures postoperatively [46]. The use of preoperative CT scanning and the planning accuracy of robotic-assisted TKA resulted in well-balanced knees [47].…”

Image-Free Robotic-Assisted Total Knee Arthroplasty Improves Implant Alignment Accuracy: A Cadaveric Study

“…Some previous studies have relied on the robot's optical tracking system to quantify resection accuracy [14,16,18e20], which neglects potentially significant errors in the registration process [23]. Other studies use preoperative and postoperative CT scans to measure resection or implant alignment angles [11,17], which allow independent quantification of the system accuracy and reduce uncertainty in establishing anatomic coordinate systems. Limitations in the CT slice thickness induce errors in segmentation of the resection surfaces which are commonly parallel to the axial slices.…”

“…Likewise, implant-induced metal artifacts cause uncertainty in alignment measures [24,25]. A study by Sires and Wilson [17] found absolute differences between resection angles measured intraoperatively and the corresponding implant alignments measured using a CT scan ranged from 1.09 ± 0.75 to 1.97 ± 1.41 for tibial coronal and sagittal alignment, respectively, with 9% of the accuracy measurements deviating by >3 . The small differences between resection angles and implant angles observed in our study suggest that much of this error may be attributed to the anatomic registration step in the RATKA workflow.…”

HURWA robotic-assisted total knee arthroplasty improves component positioning and alignment – A prospective randomized and multicenter study

“…Several robotic-assisted TKA systems, including CASPAR, Tsolution, ROSA, ROBODOC and Mako, have been implemented into clinical application [ [25] , [26] , [27] , [28] ]. Previous studies showed that robotic-assisted TKA can offer more accurate bone cuts, precise placement of implants and provide balanced extension and flexion gaps [ 29 , 30 ]. Moreover, robotic-assisted TKA can reduce the extent of bone resection and damage to the soft tissue, which are associated with postoperative pain [ 31 ].…”