The learning curve and alignment assessment of an image-free handheld robot in tka: the first patient series in Europe
ESSKA Academy. Bollars P. 11/08/19; 286407 Topic: G4 - Tricompartmental (Simple) arthroplasty
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The learning curve and alignment assessment of an image-free handheld robot in tka: the first patient series in Europe

EKA Free Papers

Topic: TKA

Bollars P., Boeckstaens A., Mievis J., Janssen D.
Orthopedie St Trudo, St Truiden, Belgium

Introduction: Total knee arthroplasty (TKA) provides pain relief, enhanced mobility, and improved quality of life. Yet, 20% of patients remain dissatisfied. The typical objective of TKA is to obtain a neutral mechanical axis of the leg. Deviation of more than 3 degrees from a neutral mechanical axis is associated with increased failure rates due to off-axis loading, polyethylene wear and subsequent implant loosening.
In April 2018, the NAVIO® Surgical System (Smith & Nephew, Pittsburgh, PA, USA) was introduced in the St.-Trudo hospital in Belgium. NAVIO enables the surgeon to plan the implant position in six degrees of freedom intraoperatively without the need for a preoperative imaging. Intra-operative adjustments allow the surgeon to optimize soft-tissue balance.
Material and methods: The first sixty-nine patients who underwent TKA with the NAVIO system by two surgeons (PB, JM) were included in this study. The JOURNEY II Bi-Cruciate Stabilized (BCS) Total Knee System implant was used in all cases. Pre- and postoperative mechanical limb alignment and balancing was measured by the NAVIO system.
Registration time, planning time and cutting time was monitored preoperatively by the NAVIO™ system. All data was analyzed retrospectively.
Results: The mean preoperative mechanical limb alignment was 3.18° varus (SD 4.28°, range 15.08° varus to 4.30° of valgus). The mean intraoperative planned angle was 0.59° varus (SD 0.97°, range 2.50° varus to 0.99° valgus). The mean postoperative alignment was 1.17° varus (SD 1.78°, range 4.52° varus to 4.33° valgus. The mean extra surgical time (EST) for registration and planning decreased from 23.4min (SD 3.7min) to 13.2min (SD 2.0) throughout the learning curve with a range of 10min05sec to 28min19sec.The mean postoperative alignment of 1.17° varus did not vary through the learning curve.
Discussion: Deviation from the neutral mechanical axis is associated with increased failure rates and decreased survival. Therefore, it is of utmost importance to achieve a neutral mechanical axis with few statistical outliers and technical errors. Our results show that the NAVIO system can reduce technical errors by providing intraoperative information and feedback about the implant position and ligament balans to the surgeon.
Operative time is expected to be longer with the use of the NAVIO robotic system. The mean EST as calculated by the sum of the registration time and planning time decreased from 23min to 13min throughout the learning curve over a duration of 7 months.
Conclusion: The NAVIO robotic system allows the surgeon to accurately determine optimal implant position and ligament balancing for each patient and minimize statistical outliers in alignment. There was no difference in postoperative limb alignment throughout the learning curve. We conclude that the NAVIO robotic system is a precise tool which minimizes technical errors with a rapid learning curve.
The learning curve and alignment assessment of an image-free handheld robot in tka: the first patient series in Europe

EKA Free Papers

Topic: TKA

Bollars P., Boeckstaens A., Mievis J., Janssen D.
Orthopedie St Trudo, St Truiden, Belgium

Introduction: Total knee arthroplasty (TKA) provides pain relief, enhanced mobility, and improved quality of life. Yet, 20% of patients remain dissatisfied. The typical objective of TKA is to obtain a neutral mechanical axis of the leg. Deviation of more than 3 degrees from a neutral mechanical axis is associated with increased failure rates due to off-axis loading, polyethylene wear and subsequent implant loosening.
In April 2018, the NAVIO® Surgical System (Smith & Nephew, Pittsburgh, PA, USA) was introduced in the St.-Trudo hospital in Belgium. NAVIO enables the surgeon to plan the implant position in six degrees of freedom intraoperatively without the need for a preoperative imaging. Intra-operative adjustments allow the surgeon to optimize soft-tissue balance.
Material and methods: The first sixty-nine patients who underwent TKA with the NAVIO system by two surgeons (PB, JM) were included in this study. The JOURNEY II Bi-Cruciate Stabilized (BCS) Total Knee System implant was used in all cases. Pre- and postoperative mechanical limb alignment and balancing was measured by the NAVIO system.
Registration time, planning time and cutting time was monitored preoperatively by the NAVIO™ system. All data was analyzed retrospectively.
Results: The mean preoperative mechanical limb alignment was 3.18° varus (SD 4.28°, range 15.08° varus to 4.30° of valgus). The mean intraoperative planned angle was 0.59° varus (SD 0.97°, range 2.50° varus to 0.99° valgus). The mean postoperative alignment was 1.17° varus (SD 1.78°, range 4.52° varus to 4.33° valgus. The mean extra surgical time (EST) for registration and planning decreased from 23.4min (SD 3.7min) to 13.2min (SD 2.0) throughout the learning curve with a range of 10min05sec to 28min19sec.The mean postoperative alignment of 1.17° varus did not vary through the learning curve.
Discussion: Deviation from the neutral mechanical axis is associated with increased failure rates and decreased survival. Therefore, it is of utmost importance to achieve a neutral mechanical axis with few statistical outliers and technical errors. Our results show that the NAVIO system can reduce technical errors by providing intraoperative information and feedback about the implant position and ligament balans to the surgeon.
Operative time is expected to be longer with the use of the NAVIO robotic system. The mean EST as calculated by the sum of the registration time and planning time decreased from 23min to 13min throughout the learning curve over a duration of 7 months.
Conclusion: The NAVIO robotic system allows the surgeon to accurately determine optimal implant position and ligament balancing for each patient and minimize statistical outliers in alignment. There was no difference in postoperative limb alignment throughout the learning curve. We conclude that the NAVIO robotic system is a precise tool which minimizes technical errors with a rapid learning curve.
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