Comparison of navigation systems for total knee arthroplasty: A systematic review and meta-analysis

Comprehensive Impact of Multiplanar Malalignment on Prosthetic Mechanics Under Gait Loading After Total Knee Arthroplasty-A Finite Element Analysis

BACKGROUND

Component alignment is a key factor influencing clinical outcomes after total knee arthroplasty (TKA). Previous studies have shown that single-plane alignment can significantly affect knee joint kinematics and biomechanics. However, the comprehensive impact of multiplanar malalignment has been rarely investigated.

OBJECTIVE

This study aimed to investigate the influence of the multiplanar malalignment combination on the polyethylene tibial liners under gait loading, a primary activity of daily life, as well as the degree of the influence of the alignments on the different planes.

METHOD

A validated finite element model of a cruciate-retaining knee prosthesis under gait loading was used in this study. Five alignment parameters (-5°, -3°, 0°, 3°, 5°) on each plane (coronal, sagittal, and transverse) were selected to simulate clinical alignment errors, resulting in 125 models combining various alignment errors across the three planes. Boundary and loading conditions were set according to ISO 14243-3:2014. The maximum von Mises stress and contact stress during a gait cycle were recorded for statistical analysis. A polynomial model was used for regression analysis, with the degree of influence of each alignment error on von Mises and contact stress determined by examining the quadratic coefficients.

RESULTS

The highest Mises and contact stress values occurred with alignment errors of 5° varus, 5° flexion, and 5° internal rotation on the coronal, sagittal, and transverse planes, respectively. The lowest stress values were observed with a combination of 3° valgus, 5° flexion, and 0° internal rotation. The regression analysis yielded an R2 value of 0.69 between alignment errors and Mises stress, with quadratic coefficients of 0.096, 0.013, and 0.064 for the coronal, sagittal, and transverse alignments, respectively. For contact stress, the R2 was 0.697, with quadratic coefficients of 0.083, 0.002, and 0.026 for the coronal, sagittal, and transverse alignments, respectively.

CONCLUSION

The coronal alignment of the lower limb has the most significant impact on both Mises stress and contact stress of the tibial liner, followed by the rotational alignment of the tibial component. In contrast, the sagittal alignment of the femoral component has the least influence.

Long-term outcomes of computer-assisted Ci™ navigation versus conventional total knee arthroplasty

OBJECTIVES

The aim of this study was to investigate the long-term effects of computer-assisted Ci™ navigation on clinical, radiological, and functional results versus conventional total knee arthroplasty (TKA).

PATIENTS AND METHODS

Between January 2005 and July 2011, a total of 85 patients (36 males, 49 females; mean age: 66.2±5.2 years; range, 59 to 84 years) who underwent P.F.C. Sigma™ knee system implantation using computer-assisted Ci™ navigation system (BrainLAB®, DePuy International, Leeds, UK) and completed a minimum follow-up of eight years were included in the study. In the control group, a total of 100 patients (40 males, 60 females; mean age: 68.3±3.9 years; range, 60 to 79 years) who completed a minimum follow-up of eight years were randomly selected from a dataset of implanted P.F.C. Sigma™ knee systems in the same period using Specialist® 2 instrumentation without navigation. An implant survival analysis was used to compare implant survivorship between the groups throughout 12 years. The Knee Society Score (KSS) and range of motion (ROM) were assessed. Based on long-format X-ray images, the implant position in the frontal and sagittal planes was evaluated.

RESULTS

The ratio for navigation to control group survival is approximately 1.01 at 12 years. The clinical outcomes showed no significant difference between the groups (knee scores, p=0.707 and functional scores, p=0.485). In the measured angles analysis, we observed a consistent pattern in both groups. In the control group, there was a trend toward implanting the tibial component with slight varus alignment (p=0.038) and a higher posterior slope (p<0.001). On average, the operation was prolonged by 13 min in the navigated group (p<0.001).

CONCLUSION

In conclusion, our study results demonstrate that while kinematic navigation in TKA improves the precision of implant alignment, it does not provide significant benefits in terms of long-term implant survival or functional outcomes compared to conventional TKA methods. The use of the computer-assisted Ci™ navigation system is associated with prolonged operation duration, although no technical complications related to the navigation device's software can be observed. Therefore, although navigation offers theoretical advantages in component positioning, its use may be more justifiable in cases with challenging alignment requirements rather than as a routine practice.

Handheld imageless robotic total knee arthroplasty improves accuracy and early clinical outcomes when compared with navigation

BACKGROUND

This study compared imageless robotic-assisted total knee arthroplasty (RATKA) with accelerometer-based navigation (ABN) systems in terms of surgical accuracy and early clinical outcomes.

METHODS

A retrospective analysis was conducted on 153 patients (178 knees) who had undergone primary TKA from 2017 to 2023. Surgical accuracy and functional outcomes were assessed up to 12 months post-operation using the Chi-square test, Student's t-test, and ANCOVA. Subgroup analyses based on patient demographics were also conducted.

RESULTS

Among 153 patients, 101 underwent RATKA, and 52 received ABN. RATKA demonstrated superior alignment accuracy with a significantly lower deviation from the planned alignment (P < 0.05). Additionally, RATKA led to significantly better postoperative functional scores at 6 weeks (P = 0.001) and 3 months (P = 0.001), even after adjusting for preoperative functional differences.

CONCLUSIONS

RATKA offers enhanced precision and improves early recovery compared to ABN, supporting its potential as a preferred technology for TKA. Its ability to optimize kinematic alignment may contribute to superior patient outcomes. Compared to ABN, RATKA provides a unique advantage by achieving greater accuracy in planned alignment, which may translate into improved functional recovery. Further research with larger cohorts is recommended to confirm these findings.

Better operating room efficiency and reduced staff demand: Individualised versus off-the-shelf total knee arthroplasty

PURPOSE

The purpose of this pilot cross-sectional study was to compare the operating room (OR) efficiency and intraoperative staff task load when performing individualised versus off-the-shelf (OTS) total knee arthroplasty (TKA).

METHODS

A consecutive series of 28 patients randomised (1:1) to receive either OTS TKA or individualised TKA were included. The OR staff workload was assessed with the NASA Task Load Index (TLX), a subjective grading system assessing mental demand, physical demand, temporal demand, performance, effort and frustration on a scale from 0 (very low) to 20 (very high). The time for patient preparation, surgical time, closure and total OR time was recorded to assess OR efficiency. Effect sizes of differences between OTS and individualised TKA were expressed as mean differences (MDs) with 95% confidence intervals (CIs).

RESULTS

Patients in both cohorts were similar in age (OTS vs. individualised TKA (median [IQR]), 67 [63-76] vs. 71 [68-79]; p = 0.207) and body mass index (BMI) (29 [24-33] vs. 29 [26-31]; p = 0.807), and there were no significant differences in other preoperative characteristics. The OR staff perceived individualised TKA as less demanding than OTS TKA: Individualised TKA was rated significantly better across the six domains of the NASA TLX: mental demand by 5.6 points, physical demand by 6.3 points, temporal demand by 5.3 points, performance by 3.6 points, effort by 5.9 points and frustration by 5.8 points. Individualised TKA resulted in statistically significantly shorter mean total OR time (MD, 10 min; p = 0.018).

CONCLUSION

The staff in the OR found that individualised TKA is less mentally, physically and temporally demanding than OTS TKA. The average total time spent in the OR during individualised TKA is 10 min less than during OTS TKA.

CLINICAL TRIAL REGISTRATION

This study constitutes a part of a larger registered randomised controlled trial comparing patient satisfaction following OTS versus individualised TKA (NCT04460989).

LEVEL OF EVIDENCE

Level III.

Early Radiographic and Clinical Outcomes of Robotic-arm-assisted versus Conventional Total Knee Arthroplasty: A Multicenter Randomized Controlled Trial

OBJECTIVE

A robotic system was recently introduced to improve prosthetic alignment during total knee arthroplasty (TKA). The purpose of this multicenter, prospective, randomized controlled trial (RCT) was to determine whether robotic-arm-assisted TKA improves clinical and radiological outcomes when compared to conventional TKA.

METHODS

One hundred and thirty patients who underwent primary TKA were enrolled in this prospective, randomized controlled trial, which was conducted at three hospitals. Five patients were lost to follow-up 6 weeks after surgery. Therefore, 125 participants (63 in the intervention group and 62 in the control group) remained in the final analysis. The primary outcome was the rate at which the mechanical axis of the femur deviated by less than 3° from the mechanical axis of the tibia. This was evaluated by full-length weight-bearing X-rays of the lower limb 6 weeks postoperatively. Secondary outcomes included operation times, 6-week postoperative functional outcomes evaluated by the American Knee Society score (KSS) and the Western Ontario and McMaster Universities osteoarthritis index (WOMAC), short form-36 (SF-36) health survey results, and the occurrence of adverse events (AEs) and serious adverse events (SAEs).

RESULTS

At 6 weeks postoperatively, we found that the rate of radiographic inliers was significantly higher in the intervention group (78.7% vs 51.6%; p = 0.00; 95% confidence interval, 10.9% to 43.2%). The operation was significantly longer in the intervention group than in the control group (119.5 vs 85.0 min; p = 0.00). There were no significant differences in the 6-week postoperative functional outcomes, SF-36, AEs, and SAEs between the two groups. There were no AEs or SAEs that were determined to be "positively related" to the robotic system.

CONCLUSION

Robotic-arm-assisted TKA is safe and effective, as demonstrated in this trial.

Total knee replacement with an accelerometer-based, hand-held navigation system improves knee alignment: reliable in all patients

BACKGROUND

Achieving adequate alignment has traditionally been an important goal in total knee arthroplasty to achieve long-term implant survival. While accelerometer-based hand-held navigation systems (ABN) has been introduced as a way to achieve alignment, there is a limited body of evidence on its accuracy, especially in patients under 65 years with differing etiologies for knee arthritis. This study aimed to assess the precision of a specific ABN system in restoring the mechanical axis and report surgical variables and complications, with particular attention to younger patients.

METHODS

We conducted a retrospective review of 310 primary TKA performed with ABN from May 2016 to February 2021. The mean patient age was 67.4 (SD 8.9) years, with 43% under 65 years and mean body mass index of 33.2 (SD 6.8). The average surgical time was 96.8 min (57-171) and the average follow-up was 3.3 years (1.9-6.7). Data regarding length of stay, pain, range of motion (ROM), complications, and reinterventions were collected from the institutional joint arthroplasty registry and the medical records. Preoperative mechanical axis measurements and postoperative radiological data, including mechanical axis, component alignment and mechanical alignment outliers were analyzed.

RESULTS

The mean preoperative mechanical axis was 175.4° (SD 7.6), with 248 knees (80%) in preoperative varus. The mean postoperative mechanical axis was 179.5° (SD 1.96) with 98% of knees falling within ± 3° of the neutral mechanical axis. Only 6 knees (2 varus, 4 valgus) fell outside the ± 3° range. And 3 knees (1 varus, 2 valgus) fell outside the ± 5° range. In the sagittal plane, 296 knees (95.5%) knees were within ± 3° of goal of 3 degrees of femoral flexion and 302 (97.4%) knees were within ± 2° of goal 1° of slope for tibial component. Far outliers (alignment outside ± 5° of targeted position) were found in 3 knees. Factors such as posttraumatic arthrosis, previous surgery, presence of retained hardware, and age below 65 years were not associated with increase in alignment outliers and far outliers. No complications related to the navigation system were observed. There were 22 complications and 20 reoperations, including 2 revisions for periprosthetic joint infection and 1 revision for flexion instability. Patients that required knee manipulation achieved an ultimate flexion of 110° (SD 14.1).

CONCLUSIONS

The ABN system proved to be user-friendly and accurate in reducing alignment outliers in both coronal and sagittal planes in all patient populations. It offers a straightforward navigation solution while preserving surgeon autonomy and the use of traditional surgical tools. These findings advocate for the integration of this navigation system as a valuable tool to enhance the precision of TKA surgery in all patient groups.

A Retrospective Study to Compare Patient Outcomes from Standard Total Knee Arthroplasty (TKA) versus Navigation-Guided Arthroplasty Using the Brainlab Software-Guided Surgical System at a Center in Hebei Province January 2021 to July 2023

BACKGROUND This retrospective study aimed to compare patient outcomes from standard total knee arthroplasty (TKA) vs navigation-guided arthroplasty using the Brainlab software-guided surgical system at Cangzhou Hospital of Integrated TCM-WM, Hebei, Hebei Province, China from January 2021 to July 2023. MATERIAL AND METHODS A total of 239 patients who underwent total knee arthroplasty in Cangzhou Hospital of Integrated TCM-WM, Hebei from January 2021 to July 2023 were retrospectively analyzed. According to the inclusion criteria, 212 eligible patients were selected for analysis and divided into a Navigation Group (NG) (n=105) and a Traditional Group (TG) (n=107) according to surgical method used. Outcomes measured included duration of disease, operative time, intraoperative blood loss volume, postoperative length of hospital stay, and pain measured by the hospital for special surgery knee score (HSS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC), and forgotten joint score (FJS). RESULTS The comparison of perioperative results between the 2 groups showed that the incision length in the NG was significantly longer than that in the TG (P<0.001, 95% Cl 2.59-3.35). At 3 months after surgery, the HSS score of the NG was statistically higher than that of the TG (P=0.002, 95% Cl 3.42-4.46); the WOMAC score of the NG was lower than that of the TG (P<0.001, 95% Cl -4.41-2.87); and the FJS score of the NG was significantly higher than that of the TG (P=0.003, 95% Cl 2.39-3.67). CONCLUSIONS Compared with conventional TKA, use of the Brainlab navigation system is associated with a longer incision, more accurate implantation position of the prosthesis, faster recovery of knee joint function, and helps patients to "forget" about their knee prosthesis in the short term.