Accuracy of Measuring Knee Flexion after TKA through Wearable IMU Sensors.

Wearable sensors have the potential to facilitate remote monitoring for patients recovering from knee replacement surgery. Using IMU sensors attached to the patients' leg, knee flexion can be monitored while the patients are recovering in their home environment. Ideally, these flexion angle measurements will have an accuracy and repeatability at least on par with current clinical standards.

How to Quantitatively Balance a Total Knee? A Surgical Algorithm to Assure Balance and Control Alignment.

To achieve a balanced total knee, various surgical corrections can be performed, while intra-operative sensors and surgical navigation provide quantitative, patient-specific feedback. To understand the impact of these corrections, this paper evaluates the quantitative impact of both soft tissue releases and bone recuts on knee balance and overall limb alignment. This was achieved by statistically analyzing the alignment and load readings before and after each surgical correction performed on 479 consecutive primary total knees.

Achieving a Balanced Knee in Robotic TKA.

Total knee arthroplasty (TKA) surgery with manual instruments provides a quantitatively balanced knee in approximately 50% of cases. This study examined the effect of combining robotics technology with real-time intra-operative sensor feedback on the number of quantitatively balanced cases in a consecutive series of 200 robotic-assisted primary TKAs. The robotics platform was used to plan the implant component position using correctable poses in extension and a manual, centrally pivoting the balancer in flexion, prior to committing to the femoral cuts.

The application of machine learning to balance a total knee arthroplasty.

Aims: The use of technology to assess balance and alignment during total knee surgery can provide an overload of numerical data to the surgeon. Meanwhile, this quantification holds the potential to clarify and guide the surgeon through the surgical decision process when selecting the appropriate bone recut or soft tissue adjustment when balancing a total knee. Therefore, this paper evaluates the potential of deploying supervised machine learning (ML) models to select a surgical correction based on patient-specific intra-operative assessments.

Robotic Total Knee Arthroplasty: Surgical Assistant for a Customized Normal Kinematic Knee.

Although current total knee arthroplasty (TKA) is considered a highly successful surgical procedure, patients undergoing TKA can still experience substantial functional impairment and increased revision rates as compared with those undergoing total hip arthroplasty. Robotic-assisted surgery has been available clinically for almost 15 years and was developed, in part, to address these concerns. Robotic-assisted surgery aims to improve TKA by enhancing the surgeon's ability to optimize soft tissue balancing, reproduce alignment, and restore normal knee kinematics.

Robotic-assisted femoral osteochondroplasty is more precise than a freehand technique in a Sawbone model.

Robotic-assistance has the potential to improve the accuracy of bony resections, when performing femoral osteochondroplasty in the treatment of cam-type femoroacetabular impingement (FAI). The purpose of this study was to determine the accuracy of robotic-assisted femoral osteochondroplasty and compare this to a conventional open, freehand technique. We hypothesized that robotic-assistance would increase the accuracy of femoral head-neck offset correction in cam FAI.

Haptically guided robotic technology in total hip arthroplasty: a cadaveric investigation.

The longevity of total hip arthroplasty (THA) continues to improve with advancements in design and bearing materials. However, the incidence of dislocation and impingement-related failures continue to rise, with the inability of the surgeon to achieve optimal component orientation cited as a cause. Computer-assistance has been shown to increase the accuracy of component orientation and robotic-assistance has been developed to translate this advantage into precise surgical execution.

Achieving accurate ligament balancing using robotic-assisted unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty (UKA) allows replacement of a single compartment in patients with limited disease. However, UKA is technically challenging and relies on accurate component positioning and restoration of natural knee kinematics. This study examined the accuracy of dynamic, real-time ligament balancing using a robotic-assisted UKA system.

Unicompartmental knee arthroplasty: is robotic technology more accurate than conventional technique?

Background: Robotic-assisted unicompartmental knee arthroplasty (UKA) with rigid bone fixation "can significantly improve implant placement and leg alignment. The aim of this cadaveric study was to determine whether the use of robotic systems with dynamic bone tracking would provide more accurate UKA implant positioning compared to the conventional manual technique.

Methods: Three-dimensional CT-based preoperative plans were created to determine the desired position and orientation for the tibial and femoral components.

Comparison of 2 femoral tunnel locations in anatomic single-bundle anterior cruciate ligament reconstruction: a biomechanical study.

Purpose: To evaluate knee stability after anterior cruciate ligament (ACL) reconstruction using 2 modern clinically relevant single-bundle constructs.

Methods: Two arthroscopic ACL reconstructions were performed on 6 fresh-frozen human cadaveric knees using bone-patellar tendon-bone autografts. The tibial tunnel was centered in the anatomic tibial footprint.

Accuracy of dynamic tactile-guided unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty (UKA) can achieve excellent clinical and functional results for patients having single-compartment osteoarthritis. However, UKA is considered to be technically challenging to perform, and malalignment of implant components significantly contributes to UKA failures. It has been shown that surgical navigation and tactile robotics could be used to provide very accurate component placement when the bones were rigidly fixed in a stereotactic frame during preparation.

Minimizing electromagnetic interference from surgical instruments on electromagnetic surgical navigation.

Background: Electromagnetic computer-assisted surgery (EM-CAS) can be affected by various metallic or ferromagnetic factors.

Questions/purposes: We determined to what extent metals interfere with accuracy and identified measures to prevent interference from occurring.

Methods: Using an EM-CAS system, we made six standard measurements of tibiofemoral position and alignment on a surrogate knee.

Does greater knee flexion increase patient function and satisfaction after total knee arthroplasty?

The purpose of this study was to determine whether high flexion leads to improved benefits in patient satisfaction, perception, and function after total knee arthroplasty (TKA). Data were collected on 122 primary TKAs. Patients completed a Total Knee Function Questionnaire.

Robotic arm-assisted UKA improves tibial component alignment: a pilot study.

Unlabelled: The alignment of the components of unicompartmental knee arthroplasty (UKA) reportedly influences outcomes and durability. A novel robotic arm technology has been developed with the expectation that it could improve the accuracy of bone preparation in UKA. During the study period, we compared the postoperative radiographic alignment of the tibial component with the preoperatively planned position in 31 knees in 31 consecutive patients undergoing UKA using robotic arm-assisted bone preparation and in 27 consecutive patients who underwent unilateral UKA using conventional manual instrumentation to determine the error of bone preparation and variance with each technique.

Implant durability and knee function after total knee arthroplasty in the morbidly obese patient.

This study investigated the effect of body mass index (BMI) on outcomes after cemented tricompartmental total knee arthroplasty (TKA). Functional and radiographic Knee Society scores in 71 patients (94 knees) with BMI 30 to 39 and 31 patients (41 knees) with BMI > or =40 were compared with 67 patients (85 knees) with BMI 20 to 29 at a mean follow-up of 5.4 years.

Technology and cost-effectiveness in knee arthroplasty: computer navigation and robotics.

Our aim in this article is to describe the impact that navigation technology has had on the market share of a community hospital and, specifically, to determine whether a high-volume surgeon using these technologies actually costs the hospital more than other surgeons at the same hospital and more than national means. In addition, we develop a comparable cost-effectiveness model for robotic technology in unicompartmental knee arthroplasty to demonstrate the potential cost-effectiveness at the same hospital.

Minimally invasive robotic-arm-guided unicompartmental knee arthroplasty.

Unicompartmental knee arthroplasty is an underused procedure in orthopaedic surgery due to its level of difficulty and the unpredictability of results, which can be related to component malalignment. New robotic arm technology has been developed to assist the surgeon in accurately and reproducibly preparing the femur and the tibia for a minimally invasive bone-sparing unicompartmental knee arthroplasty. This new procedure provides comprehensive three-dimensional planning of unicompartmental knee arthroplasty components, including soft-tissue balancing, followed by accurate resection of the femur and the tibia.

Comparison of isometric and anatomic reconstruction of the medial patellofemoral ligament: a cadaveric study.

Recent surgical procedures designed to correct recurrent posttraumatic lateral patellar instability focus on reconstructing the medial patellofemoral ligament. This study evaluated and compared patellofemoral kinematics of isometric and anatomic medial patellofemoral ligament reconstructions. Using an infrared motion capture analysis system, patellar tracking was evaluated in the coronal plane in 6 cadaveric specimens.

Fiber Bragg grating displacement sensor for movement measurement of tendons and ligaments.

Biomechanical studies often involve measurements of the strains developed in tendons or ligaments in posture or locomotion. Fiber-optic sensors present an attractive option for the measurement of strains in tendons and ligaments because of their low cost, ease of implementation, and increased accuracy compared with other implantable transducers. A new displacement sensor based on a fiber Bragg grating and shape memory alloy technology is proposed for the monitoring of tendon and ligament strains in different postures and in locomotion.

A computerized bioskills system for surgical skills training in total knee replacement.

Although all agree that the results of total knee replacement (TKR) are primarily determined by surgical skill, there are few satisfactory alternatives to the 'apprenticeship' model of surgical training. A system capable of evaluating errors of instrument alignment in TKR has been developed and demonstrated. This system also makes it possible quantitatively to assess the source of errors in final component position and limb alignment.

The John Insall Award: Patient expectations affect satisfaction with total knee arthroplasty.

Satisfaction with the outcome of total knee arthroplasty is highly variable, with a small but significant percentage of patients reporting dissatisfaction with the procedure. The purpose of this study was to determine which factors contribute to patient satisfaction with total knee replacement (TKR), and their relative importance. At a minimum of 1 year post unilateral primary TKR, 253 patients completed a self-administered, validated "Knee Function Questionnaire," which examined each patient's participation in a broad range of activities involving the knee, their level of satisfaction, and the extent to which TKR had fulfilled their expectations.