Can Robotic-Arm Assistance Decrease Iatrogenic Soft-Tissue Damage During Direct Anterior Total Hip Arthroplasty?

INTRODUCTION: Manual techniques for total hip arthroplasty (THA) have been widely utilized and proven to be clinically successful. However, the use of advanced computed tomography (CT) scan-based planning and haptically-bounded reamers in robotic-arm assisted total hip arthroplasty (RTHA) holds promise for potentially limiting surrounding soft-tissue damage. This cadaver-based study aimed to compare the extent of soft-tissue damage between a robotic-arm assisted, haptically-guided THA (RTHA) and a manual, fluoroscopic-guided THA (MTHA) direct anterior approach. MATERIALS AND METHODS: There were six fresh-frozen torso-to-toe cadaver specimens included, with two surgeons each performing three RTHA and three MTHA procedures. One hip underwent an RTHA and the other hip received an MTHA in each cadaver. Postoperatively, one additional surgeon, blinded to the procedures, assessed and graded damage to nine key anatomical structures using a 1 to 4 grading scale: (1) complete soft-tissue preservation to <5% of damage; (2) 6 to 25% of damage; (3) 26 to 75% of damage; and (4) 76 to 100% of damage. Kruskal-Wallis hypothesis tests were used to compare soft-tissue damage between RTHA and MTHA cases and adjusted for ties. RESULTS: Pooled analysis of the gluteus minimus, sartorius, tensor fascia lata, and vastus lateralis muscle grades demonstrated that cadaver specimens who underwent RTHA underwent less damage to these structures than following MTHA (median, IQR: 1.0, 1.0 to 2.0 vs. 3.0, 2.0 to 3.0; p=0.003). Pooled analysis of the calculated volumetric damage (mm3) for the gluteus minimus, sartorius, tensor fascia lata, and vastus lateralis muscles demonstrated that the cadaver specimens that underwent RTHA underwent less damage to these structures than those that followed MTHA (median, IQR: 23, 2 to 586 vs. 216, 58 to 3,050; p=0.037). CONCLUSION: This cadaver-based study suggests that utilizing RTHA may lead to reduced soft-tissue damage compared with MTHA, likely due to enhanced preoperative planning with robotic-arm assisted software, real-time intraoperative feedback, haptically-bounded reamer usage, reduced surgical steps, as well as ease of use with reaming. These findings should be carefully considered when evaluating the utilization of robotic-arm assisted THA in practice.

Robotic-assisted Total Knee Arthroplasty Technology Provides a Repeatable and Reproducible Method of Assessing Soft Tissue Balance.

Soft-tissue balancing is an important factor in primary total knee arthroplasty (TKA), with 30 to 50% of TKA revisions attributed to technical operative factors including soft-tissue balancing. Robotic-assisted TKA (RATKA) offers opportunities for improved soft-tissue balancing methods. This study aimed to evaluate the repeatability and reproducibility of ligamentous laxity assessments during RATKA using a digital tensioner.Three experienced RATKA surgeons assessed preresection and trialing phases of 12 human cadaveric knees with varying degrees of arthritis. Ligamentous laxity was assessed with manual varus and valgus stresses in extension and flexion, with a digital tensioner providing feedback on the change of laxity displacement. Intraclass correlation coefficient (ICC) analyses were used to determine the repeatability within a single surgeon and reproducibility between the three surgeons.The results showed excellent repeatability and reproducibility in ligamentous laxity assessment during RATKA. Surgeons had excellent repeatability for preresection and trialing assessments, with median ICC values representing excellent reproducibility between surgeons. Surgeons were repeatable within 1 or 1.5 mm for preresection and trialing assessments. On average, the variation within a surgeon was 0.33 ± 0.26 mm during preresection and 0.29 ± 0.28 mm during trialing. When comparing surgeons to each other, they were reproducible within an average of 0.69 ± 0.33 mm for preresection and 0.65 ± 0.31 mm for trialing.This study demonstrated the reliability of robotic-assisted soft-tissue balancing techniques, providing control over ligamentous laxity assessments, and potentially leading to better patient outcomes. The digital tensioner used in this study provided excellent repeatability and reproducibility in ligamentous laxity assessment during RATKA, highlighting the potential benefits of incorporating robotics in TKA procedures.

Using Software to Implant Orthopaedic Hardware: Surgeon Intraoperative Confidence Increased with Latest Technological Updates.

BACKGROUND: Robotic-assisted total knee arthroplasty (TKA) has been associated with improved accuracy and precision of implant placement, protection of soft tissue, and improved patient-reported postoperative outcomes when compared to manual TKA techniques. Previous studies have highlighted the importance of surgical confidence throughout the learning curve when adopting robotic-assisted platforms. The purpose of this study was to evaluate the confidence and efficiencies of surgeons when utilizing computed tomography (CT)-based robotic TKA technology. MATERIALS AND METHODS: A cross-sectional, questionnaire-based study was conducted with 20 arthroplasty-trained surgeons with prior experience in both manual TKA and robotic-assisted TKA techniques. The surgeons completed an initial learning period, with new software, during various stages of their experience. The new TKA software upgrade builds on the prior software version with new features. A Net Promoter Score (NPS), the measurement of a respondent's likelihood to recommend a product or service to others, was used during the analysis of survey questions. A NPS over 50 indicates a positive score. RESULTS: When compared to manual TKA techniques, 95% of surgeons reported that their overall intraoperative confidence increased with the new software upgrade for CT-based robotic technology and had an average rating of 8.9 out of 10 for their intraoperative confidence with the new software upgrade. Additionally, 100% of surgeons reported that they were more confident when performing intraoperative implant adjustments with the new software upgrade when compared to manual TKA. Surgeons determined that the overall use of the new software upgrade was intuitive (8.4 of 10 average rating) and were satisfied with the overall use of the new software upgrade (9 of 10 average rating). Also, surgeons reported that they would recommend the new software upgrade for CT-based robotic technology to colleagues (NPS of 85), as well as being used as a research tool (NPS of 85) or for a training and education tool in a fellowship program (NPS of 90). CONCLUSION: As new technology continues to enter the field of orthopedics, it is important to ensure upgrades and advancements continue to serve surgeons and provide efficiencies in the operating room. For established robotic surgeons, the new robotic technology assessed in this study provided increased confidence when compared to manual TKA. Based on these results, the new software upgrade demonstrated value during various stages of a TKA procedure and is highly recommended for use by others in the field of orthopedics.