Kinematics of bicruciate and posterior stabilized total knee arthroplasty during deep knee flexion and stair climbing

Does Cruciate Ligament Substitution and Implant Asymmetry Make a Difference for Total Knee Arthroplasty Kinematics? A Multi-Implant Evaluation

BACKGROUND

The non-implanted knee differs in comparison to total knee arthroplasty (TKA) designs, with regard to asymmetry and functionality of the anterior cruciate ligament and the posterior cruciate ligament. While surgeons may choose to implant either posterior stabilized (PS) or bi-cruciate stabilized (BCS) TKAs, substituting for one or both cruciate ligaments, the effects of symmetry versus asymmetry in substituting TKA designs have not been widely analyzed to determine possible benefits. Therefore, the objective of this research study was to determine if either TKA asymmetry and/or anterior ligament stabilization can lead to more normal-like kinematics and clinical benefit for patients.

METHODS

In vivo, femoro-tibial kinematics for 64 subjects were evaluated in this retrospective study. Overall, 10 subjects had a normal, nonimplanted knee, 20 had a BCS TKA, and 34 had one of two different PS TKAs. All three TKAs had varying degrees of symmetry incorporated into the design, and all were implanted by the same surgeon and were analyzed using fluoroscopy during a deep knee bend.

RESULTS

At full extension, the BCS TKA subjects demonstrated a statistically more anterior position of both condyles compared to both PS TKAs. The BCS TKA subjects also experienced more posterior femoral rollback (PFR) and axial rotation in early flexion and from full extension to maximum knee flexion. Additionally, the TKAs in this study having asymmetry experienced greater amounts of PFR and weight-bearing knee flexion.

CONCLUSIONS

The results from this study indicated that in early flexion, the anterior cam/post mechanism does pull the femoral component more anterior, and all TKAs experienced PFR when the posterior cam engaged the post. The asymmetric designs also achieved greater rollback and axial rotation compared to the symmetric designs.

Patient-Reported Outcome Measures and Biomechanical Variables That May Be Related to Knee Functions Following Total Knee Arthroplasty

Total knee arthroplasty (TKA) is a commonly performed surgery aimed at alleviating pain and improving functionality. However, patients often face uncertainties in selecting the timing, location, and type of TKA implant that best meets their needs. This study aims to comprehensively compare various variables, explore trends, and identify factors potentially influencing TKA outcomes. A cohort of 40 TKA subjects received either unilateral posterior stabilized (Persona) TKA or bi-cruciate stabilized (Journey II) TKA. Additionally, 20 healthy controls matched for age, gender, and BMI were included. Participants underwent patient-reported outcome assessments, range of motion evaluations, balance assessments, proprioception tests, and biomechanical analyses. These analyses covered motion, loading, and electromyography during five daily activities and two clinical tests. Multifactor ANOVA was utilized to compare 283 variables and assess their impact on TKA outcomes. A knee biomechanics index was formulated to evaluate deviations from healthy norms. Significant differences were observed in EMG varus/valgus rotation during both ramp-up and ramp-down phases between the two implant groups. Although significant improvements were noted post-TKA for both implants, the results remained below those of the control group. Gender, age, and BMI exhibited noticeable effects on TKA outcomes across several biomechanical variables and demonstrated significant disparities compared to the controls.

Native knee kinematics are reproduced during the golf swing after total knee arthroplasty apart from rotation: A case control study of hip and knee kinematics of patients returning to golf compared to match controls

OBJECTIVES

Golf is a popular sport in older adults and this same population has an increasing prevalence of osteoarthritis affecting major joints such as the knee. To the authors' knowledge, the effect of Total Knee Arthroplasty (TKA) on the movements in the golf swing has not been extensively investigated despite the large prevalence of golfers who have undergone TKA. We aimed to determine lower limb joint kinematics during the golf swing and whether these are influenced following TKA.

METHODS

A case- control study was undertaken with ten right-handed golfers who had undergone TKA (cruciate-retaining single radius implant) and five matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200 ​Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events.

RESULTS

The left knee demonstrated large effect sizes for lower external rotation during take away, mid (p ​= ​0.01) and top of backswing in the TKA group. In contrast, the right knee demonstrated large effect sizes for lower external rotation in the TKA group during the downswing, contact and follow-through phases. There were no differences in knee flexion/extension, ab/adduction, or JAV between the groups. Both hips demonstrated statistically significantly (p ​= ​0.02 for left and p ​= ​0.04 for right) lower flexion in the TKA group during the takeaway swing event, and lower internal rotation in the backswing and greater external rotation in the downswing of the right hip.

CONCLUSION

Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the backswing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee.

LEVEL OF EVIDENCE

IV.

Comparison of the in vivo kinematics between robotic-assisted Bi-cruciate retaining and Bi-cruciate stabilised total knee arthroplasty

BACKGROUND

Up to 20% of patients remain unsatisfied after total knee arthroplasty (TKA), prompting the development of new implants. Bi-Cruciate Retaining (BCR) TKA preserves both the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL), with the ACL beneficial for its proprioceptive qualities. The Bi-Cruciate Stabilised (BCS) TKA substitutes the ACL and PCL with a unique dual cam-post mechanism. Robotics improve accuracy and facilitate technically demanding TKA.

METHODS

This was a retrospective case-control study recruited from two centres. Measured outcomes included kinematic analysis, proprioception, and functional outcomes.

RESULTS

There was a significantly larger maximum flexion angle and range of flexion to extension in sit-to-stand and stairs in BCR when compared to BCS. Further analysis revealed more similarities between BCR and normal native knees. Proprioception and functional scores did not have any statistical difference.

CONCLUSION

BCR TKA demonstrated better knee flexion in weight-bearing active range of motion and showed similarities with normal knee kinematics.

Effect of single-radius design on in vivo kinematics during stair activities after total knee arthroplasty

BACKGROUND

The single-radius design is one of the major total knee arthroplasty (TKA) designs and widely used all over the world. The objective of this study was to compare in vivo kinematics between the anteroposterior (AP) single-radius design with mediolateral (ML) single-radius (Non Restricted Geometry; NRG) and ML dual-radius (Triathlon) during stair activities.

METHODS

A total of 21 knees in 18 patients (NRG group: 10 knees in 7 patients, Triathlon group: 11 knees in 11 patients) with a clinically successful posterior stabilized TKA were examined. Under fluoroscopic surveillance, each patient performed stair ascending and descending motions. In vivo kinematics were analyzed using 2D/3D registration technique. The knee flexion angle, rotation angle, varus-valgus angle, AP translation of the femorotibial contact point for both the medial and lateral sides of the knee, and post-cam engagement were evaluated.

RESULTS

There were no significant differences between the two groups in rotation angle and AP translation at each flexion angle. Examining the varus-valgus angle, the NRG group showed varus position at an early flexion angle during both stair activities.Post-cam engagement was observed in both groups during both stair activities. The mean flexion angle of engagement in the NRG group, the post of which was located anterior to the Triathlon, was larger than that in the Triathlon group during both stair activities.

CONCLUSION

Despite the same AP single-radius TKA, ML single-radius might affect varus motion at an early flexion angle.

Reliability and validity of pose estimation algorithm for measurement of knee range of motion after total knee arthroplasty

We aimed to assess the reliability and validity of OpenPose, a posture estimation algorithm, for measurement of knee range of motion after total knee arthroplasty (TKA), in comparison to radiography and goniometry. In this prospective observational study, we analyzed 35 primary TKAs (24 patients) for knee osteoarthritis. We measured the knee angles in flexion and extension using OpenPose, radiography, and goniometry. We assessed the test-retest reliability of each method using intraclass correlation coefficient (1,1). We evaluated the ability to estimate other measurement values from the OpenPose value using linear regression analysis. We used intraclass correlation coefficients (2,1) and Bland-Altman analyses to evaluate the agreement and error between radiography and the other measurements. OpenPose had excellent test-retest reliability (intraclass correlation coefficient (1,1) = 1.000). The R2 of all regression models indicated large correlations (0.747 to 0.927). In the flexion position, the intraclass correlation coefficients (2,1) of OpenPose indicated excellent agreement (0.953) with radiography. In the extension position, the intraclass correlation coefficients (2,1) indicated good agreement of OpenPose and radiography (0.815) and moderate agreement of goniometry with radiography (0.593). OpenPose had no systematic error in the flexion position, and a 2.3° fixed error in the extension position, compared to radiography. OpenPose is a reliable and valid tool for measuring flexion and extension positions after TKA. It has better accuracy than goniometry, especially in the extension position. Accurate measurement values can be obtained with low error, high reproducibility, and no contact, independent of the examiner's skills.

Kinematics of bicruciate stabilized and cruciate retaining total knee arthroplasty

Few studies have been reported about kinematic comparison between bicruciate stabilized and cruciate retaining total knee arthroplasty with the same anatomical surface geometry. The aim of this study was to demonstrate the in vivo kinematics and postoperative patient-reported outcomes of these two surgeries with the same anatomical surface geometry. We analyzed 17 bicruciate stabilized and 18 cruciate retaining total knee arthroplasties using single-plane fluoroscopic surveillance with two- to three-dimensional registration techniques during squatting from minimum to maximum flexion. Flexion angle, femoral external rotation, anteroposterior position of the medial and lateral sides, and postoperative 2011 Knee Society Scores were analyzed. Maximum flexion angles were larger for bicruciate stabilized than for cruciate retaining total knee arthroplasties. There was no significant difference in femoral external rotation between the two types. The medial and lateral femoral condyles in bicruciate stabilized type translated more posteriorly during deeper flexion and at maximum flexion angle, respectively, than those in cruciate retaining total knee arthroplasty. Both groups revealed medial pivots in early flexion, but during deep flexion, bicruciate stabilized total knee arthroplasty revealed bicondylar roll-back and cruciate retaining total knee arthroplasty revealed paradoxical anterior motion. Both groups exhibited similar results in postoperative 2011 Knee Society Scores. Bicruciate stabilized and cruciate retaining total knee arthroplasties with the same anatomical articular surfaces demonstrated different kinematics patterns during squatting. However, there were no significant differences in postoperative 2011 Knee Society Scores between the two types of surgery.

Kinematic comparison between asymmetrical and symmetrical polyethylene inserts during deep knee bend activity

BACKGROUND

The in vivo kinematic benefit of an asymmetrical polyethylene insert is still unknown in comparison with that of a symmetrical insert with the same femoral component design. The purpose of this study was to analyze the kinematic differences between symmetrical and asymmetrical polyethylene inserts and to detect the kinematic benefit in the asymmetrical polyethylene insert. The hypotheses are that greater axial rotation and more posterior rollback are observed in the asymmetrical polyethylene insert.

METHODS

The patients were randomly allocated to the following two groups: total knee arthroplasty with a symmetrical insert and with an asymmetrical insert. In vivo knee kinematics was analyzed in asymmetrical (17 knees) and symmetrical (16 knees) inserts using an image matching technique. The symmetrical polyethylene insert had the same geometry on both sides, whereas the asymmetrical polyethylene insert had a flat surface on the postero-lateral side. The anterior/posterior position and axial rotation were compared between the two polyethylene inserts.

RESULTS

The femoral component was significantly positioned posteriorly at 70° (p = 0.016) and 80° (p = 0.040) of knee flexion and externally rotated at 80° of knee flexion (p = 0.040) in the asymmetrical polyethylene insert as compared to the position of the symmetrical polyethylene insert. Femoral rollback and axial rotation from full extension to maximum flexion were greater in the asymmetrical polyethylene insert, although the difference was not significant.

CONCLUSIONS

In the asymmetrical polyethylene insert, slight kinematic benefit with greater axial rotation and more posterior rollback was observed in comparison with the symmetrical polyethylene insert. Further research should be required whether the kinematic benefit of an asymmetrical polyethylene insert will lead to better patient satisfaction and function.

Femoral rollback at high-flexion during squatting is related to the improvement of sports activities after bicruciate-stabilized total knee arthroplasty: an observational study

BACKGROUND

In bicruciate-stabilized total knee arthroplasty (BCS-TKA), the relationship between the postoperative kinematics and sports subscales in patient-reported outcome measures (PROMs) remains unknown. The purpose of this study was to determine the relationship between kinematics and sports subscales using the PROMs after BCS-TKA.

METHODS

Sixty-one patients with severe knee osteoarthritis were examined at 13.5 ± 7.8 months after BCS-TKA. The patients performed squats under single fluoroscopic surveillance in the sagittal plane. Range of motion of the knee, axial rotation of the femur relative to the tibial component, and anteroposterior (AP) translation of the medial and lateral femorotibial contact points were measured using a 2D-to-3D registration technique. In addition, the relationship between the kinematics and improvement of the sports subscales in the Knee Injury and Osteoarthritis Outcome Score (KOOS) was evaluated.

RESULTS

In rotation angle, the femoral external rotation was observed from 0 to 50° of flexion. The amount of femoral external rotation did not correlate with PROMs-SP. In medial AP translation, posterior translation was observed from 0 to 20° and 80-110° of flexion. Mild anterior translation was observed from 20 to 80° of flexion. Beyond 80° of flexion, posterior translation was positively correlated with squatting. In lateral AP translation, posterior translation was observed from 0 to 20° and 80-110° of flexion. Beyond 80° of flexion, posterior translation was positively correlated with running, jumping, twisting/pivoting, and kneeling.

CONCLUSION

Femoral rollback at high flexion during squatting may be important to improve sports performance after BCS-TKA.