Influence of component design on in vivo tibiofemoral contact patterns during kneeling after total knee arthroplasty: a systematic review and meta-analysis

Effectiveness of kneeling training in improving mobility and balance post-stroke

BACKGROUND

Fall prevention and balance control constitute critical components of rehabilitation for stroke survivors. Kneeling training, characterized by its low center of gravity focus, has been incorporated into rehabilitation regimens to enhance postural control across various pathological conditions. Despite its widespread use, empirical evidence substantiating the efficacy of kneeling training is limited, particularly in the context of mobility and balance improvement for patients who have had a stroke. This study aims to substantiate the safety and effectiveness of kneeling training in individuals recovering from stroke.

METHODS

A randomized controlled trial comparing kneeling training and conventional rehabilitation training was conducted, involving sixty-seven participants allocated to the Kneeling Training Group (KNT) and the Conventional Rehabilitation Group (CVR). The KNT group underwent 30-minute sessions of kneeling training, while the CVR group received conventional treadmill walking training, both administered six times per week over four weeks. Evaluation encompassed the Fugl-Meyer Assessment for Lower Extremity (FMA-LE), the Berg Balance Scale (BBS), and gait analysis was conducted at baseline, as well as at the 2 and 4-week intervals.

RESULTS

Our study established the safety of a 4-week kneeling training program. Notably, the KNT group exhibited more pronounced improvements in BBS scores at weeks 2 and 4 compared to the CVR group. However, no significant disparities emerged in FMA-LE and gait analysis between the two groups. Our findings suggest that kneeling training may serve as a viable option for enhancing lower limb balance in survivors who have had a stroke.

CONCLUSIONS

We conclude that kneeling training, characterized by its safety, simplicity, and no restrictions on location or equipment, represents a valuable therapeutic approach for enhancing walking balance in individuals recovering from stroke.

TRIAL REGISTRATION

Clinical trials ChiCTR1900028385, December 20, 2019.

Ball-in-socket medial conformity with posterior cruciate ligament retention neither limits internal tibial rotation and knee flexion nor lowers clinical outcome scores after unrestricted kinematically aligned total knee arthroplasty

PURPOSE

For a new tibial insert design with ball-in-socket (B-in-S) medial conformity (MC), posterior cruciate ligament (PCL) retention, and flat lateral articular surface (B-in-S MC + PCL), this study determined whether internal tibial rotation and knee flexion were limited and clinical outcome scores were lower during weight-bearing activities relative to an insert with intermediate (I) (i.e., less than ball-in-socket) medial conformity (I MC + PCL).

METHODS

Twenty-five patients were treated with bilateral unrestricted, caliper-verified kinematic alignment (KA) total knee arthroplasty (TKA) with an I MC + PCL insert and B-in-S MC + PCL insert in opposite knees. Each patient performed weight-bearing deep knee bend, step up, and chair rise under single-plane fluoroscopy. Analysis following 3D model-to-2D image registration determined internal tibial rotation. For each TKA, knee flexion was measured and patients completed clinical outcome scoring questionnaires.

RESULTS

Internal tibial rotation did not differ between conformities during chair rise and step up (p = 0.3419 and 0.1030, respectively). During deep knee bend, internal tibial rotation between 90° and maximum flexion was 3° greater in the B-in-S MC + PCL group (18° vs 15°) (p = 0.0290). Mean knee flexion (p = 0.3115) and median Forgotten Joint Score (FJS), Oxford Knee Score (OKS), and Western Ontario and McMasters Universities Arthritis Index (WOMAC) scores (p = 0.2100, 0.2154, and 0.4542, respectively) did not differ between conformities.

CONCLUSION

An insert with ball-in-socket medial conformity, which maximizes anteroposterior (AP) stability, did not limit internal tibial rotation and knee flexion and did not lower patient-reported outcomes when implanted with unrestricted caliper-verified KA and PCL retention. The high AP stability provided by the medial ball-in-socket might interest those surgeons exploring the treatment of the active patient with a desire to return to high-level and athletic activities.

Comparative Analysis of Contemporary Fixed Tibial Inserts: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials

Background

Multiple options are available for the tibial insert in total knee arthroplasty (TKA). A systematic review (SR) and network meta-analysis (NMA) to compare available randomized controlled trials (RCTs) could assist with decision making. We aim to show that designs with increased conformity may improve function and satisfaction without an increase in complications though posterior stabilized (PS) inserts will likely have more flexion.

Methods

A search of MEDLINE, EMBASE, and the Cochrane Library was performed. Studies were limited to RCTs evaluating cruciate retaining (CR), PS, anterior stabilized (AS), medial pivot (MP), bicruciate retaining (BR), and bicruciate stabilizing (BCS) inserts. Mean differences (MD) were used for patient reported outcome measures (PROMs) and odds ratios (OR) for reoperation rates and MUA. A systematic review was performed for satisfaction.

Results

27 trials were identified. The NMA showed no difference from a statistical or clinical standpoint for PROMs evaluated. There was a statistical difference for increased flexion for PS knees (3 degrees p 0.04). There were no differences in the MUA or reoperation rates. There was insufficient information to determine if a specific insert improved satisfaction.

Discussion

The results of this NMA show no statistical or clinical difference in PROMs. There was higher flexion for PS knees though the amount was not clinically significant. There was insufficient data for conclusions on patient satisfaction. Therefore, the surgeon should evaluate the clinical situation to determine the best insert rather than choose and insert based on functional scores, patient satisfaction, or complication rates.

Has the modern design of Attune total knee replacement improved outcome in patients with isolated patellofemoral arthritis?

INTRODUCTION AND AIM

Modern knee replacements aim to improve patient function in arthritis affecting different compartments of the knee. This study evaluates the Patient Reported Outcome Measure (PROM) and functional outcome of a modern total knee replacement (Attune, DePuy) in patients with isolated patellofemoral arthritis.

METHODS

A total of 50 consecutive patients with isolated unilateral patellofemoral arthritis having had Attune total knee replacements at a single institution between 2010 and 2016 were prospectively studied. Five patients who developed symptoms on the opposite side during the study and two patients lost to follow-up were excluded. One patient needed early revision for loosening, leaving a total of 42 patients to be followed up over a period of 4 years. The Oxford Knee score (OKS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) recorded pre-operatively and at follow-up was compared. A Functional assessment at around 8 months after operation was undertaken.

RESULTS

At average follow-up of 24 months the mean OKS score improved by 15 points and the KOOS score improved by 20 points. Final KOOS sub-score for Pain was 80, Symptom 80, and ADL 82, Sports & Recreation 32 and QOL 60. Functional assessment at mean 8 months showed that a significant number of patients were able to Kneel (50%); Sit cross legged (23%); sit on their heel (23%) and were able do a single leg dip test (86%).

CONCLUSION

This unique study of a modern design total knee replacement (Attune) in patients with isolated unilateral patellofemoral arthritis shows good PROM scores at 2 years and good functional assessment results at 8 months. The PROM scores are marginally better than the published results with Attune's predecessor, in a similar cohort of patients, but falls short of the published results of patellofemoral replacement implants. Large randomised comparative studies between traditional and the modern implant design is recommended to answer the question if design modification has influenced clinical outcome in patients with patellofemoral arthritis.

The effect of sacrificing the posterior cruciate ligament on total knee arthroplasty with cruciate retaining highly congruent rotating platform prosthesis

Objective

To analyze the effect of sacrificing the posterior cruciate ligament (PCL) on the early postoperative outcome of cruciate retaining (CR) highly congruent rotating platform TKA.

Methods

From May 2018 to September 2019, 105 cases of total knee arthroplasty (TKA) with CR highly congruent rotating platform prosthesis were retrospectively analyzed. According to the tension of posterior cruciate ligament, they were divided into sacrifice group (29 cases, 27.6%) and retention group (76 cases, 72.4%). Preoperative and postoperative The Hospital for Special Surgery (HSS) score, range of motion (ROM) were compared between the two groups. In addition, postoperative infection, prosthesis loosening, bearing dislocation, and other complications were also compared.

Results

All patients were followed up for 11~24 months (mean 18.14 ± 3.52) months. There was no significant difference in general data, preoperative HSS score, and ROM between the two groups (P > 0.05). At the last follow-up, HSS score and ROM of the two groups were better than those before operation (P < 0.05). However, there was no significant difference between the two groups (P > 0.05). Moreover, there were no complications such as infection, loosening of prosthesis, and bearing dislocation in all cases.

Conclusion

In CR, highly congruent rotating platform TKA with or without tension of the PCL can achieve satisfactory outcomes. Tension-free PCL do not cause joint instability.

The influence of total knee arthroplasty design on kneeling kinematics: a prospective randomized clinical trial

AIMS

Modern total knee arthroplasty (TKA) prostheses are designed to restore near normal kinematics including high flexion. Kneeling is a high flexion, kinematically demanding activity after TKA. The debate about design choice has not yet been informed by six-degrees-of-freedom in vivo kinematics. This prospective randomized clinical trial compared kneeling kinematics in three TKA designs.

METHODS

In total, 68 patients were randomized to either a posterior stabilized (PS-FB), cruciate-retaining (CR-FB), or rotating platform (CR-RP) design. Of these patients, 64 completed a minimum one year follow-up. Patients completed full-flexion kneeling while being imaged using single-plane fluoroscopy. Kinematics were calculated by registering the 3D implant models onto 2D-dynamic fluoroscopic images and exported for analysis.

RESULTS

CR-FB designs had significantly lower maximal flexion (mean 116° (SD 2.1°)) compared to CR-RP (123° (SD 1.6°)) and PS-FB (125° (SD 2.1°)). The PS-FB design displayed a more posteriorly positioned femur throughout flexion. Furthermore, the CR-RP femur was more externally rotated throughout kneeling. Finally, individual patient kinematics showed high degrees of variability within all designs.

CONCLUSION

The increased maximal flexion found in the PS-FB and CR-RP designs were likely achieved in different ways. The PS-FB design uses a cam-post to hold the femur more posteriorly preventing posterior impingement. The external rotation within the CR-RP design was surprising and hasn't previously been reported. It is likely due to the polyethylene bearing being decoupled from flexion. The findings of this study provide insights into the function of different knee arthroplasty designs in the context during deep kneeling and provide clinicians with a more kinematically informed choice for implant selection and may allow improved management of patients' functional expectations. Cite this article: Bone Joint J 2021;103-B(1):105-112.