Kinematic Alignment May Reduce Opioid Consumption and Length of Stay Compared to Mechanically Aligned Total Knee Arthroplasty

Revision of Well-Fixed Mechanically-Aligned Total Knee Arthroplasty Using Kinematic Alignment for the Restoration of Joint Line Obliquity: Report of a Surgical Technique

Despite advances in technology and procedures, primary total knee arthroplasty can still result in an unsatisfied patient up to 20% of the time. Many indications for revising total knee arthroplasty have been established, including infection, aseptic loosening, wear, and instability. A newer indication being used in our center is that of a mechanically aligned knee, in which the prosthetic joint line has been substantially altered with respect to the native joint line. In this surgical technique report, we describe a method of revising a painful mechanically aligned total knee arthroplasty using the principles of kinematic alignment, using either the patient's preoperative long-axis radiographs, if available, or those of their contralateral limb, as a guide for the measurement of native joint line obliquity. Although this may be controversial, in our practice, this diagnosis has become an established indication for revision knee arthroplasty, with high success rates and patient satisfaction. In this brief surgical technique report, we present the details of one of our cases.

Mechanical versus kinematic alignment for total knee arthroplasty: a meta-analysis

INTRODUCTION

The present meta-analysis compared mechanical versus kinematic alignment in total knee arthroplasty (TKA). The outcomes of interest were patient-reported outcome measures (PROMs), range of motion (ROM), and revision rate.

METHODS

This study was conducted according to the 2020 PRISMA statement. In July 2024, PubMed, Web of Science, Google Scholar, and Embase were accessed without time constraints. All the clinical studies that compared mechanical versus kinematic alignment in total knee arthroplasty were accessed.

RESULTS

30 studies (3133 TKAs) were collected. The mean duration of the follow-up was 30.8 ± 38 months. No difference was found in Knee KSS-F, Knee Society Score (KSS, P = 0.2) and its function subscale (P = 0.3), visual analogue scale (VAS, P = 0.3), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC, P = 0.2), Oxford Knee Score (OKS, P = 0.5). No difference was found in the rate of revision (P = 0.4). The ROM was slightly greater in the kinematic group (P < 0.0001).

CONCLUSION

PROMs and revision did not show a difference between mechanical and kinematic alignment in TKA. However, a minimal difference in the ROM was evidenced, which probably does not have clinical relevance.

LEVEL OF EVIDENCE

Level IV, systematic review and meta-analysis.

Implementability of opioid deprescribing interventions at transitions of care: A scoping review

Continuation of opioids at transitions of care increases the risk of long-term opioid use and related harm. To our knowledge, no study has examined the implementability of opioid deprescribing interventions at transitions of care. Our scoping review aimed to identify the type of opioid deprescribing interventions employed at transitions of care and assess the implementability of tested interventions. Nine electronic databases were searched on 15 May 2023 for English-language studies of adults transitioning between care settings, where opioid deprescribing interventions targeting patients, clinicians or health systems were implemented. Implementability was assessed using the Cochrane Intervention Complexity Assessment Tool for Systematic Reviews to determine intervention complexity, and mapped to the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework to understand the process evaluation. A total of 79 studies were identified, with 94.0% (n = 74) examining hospital-to-home transitions. Mixed interventions (combination of pharmacological and nonpharmacological) were tested in 49.0% (n = 39) of studies. Pharmacological interventions were identified in 31.0% (n = 24) of studies, and the remaining 20.0% (n = 16) applied nonpharmacological interventions. Mixed interventions comprising multiple components were the most complex and resulted in reduced opioid use across transitions of care in 28.0% (n = 22) of studies. Few studies reported on RE-AIM dimensions including implementation (5.0% of studies), reach (4.0%), adoption (4.0%) and maintenance (0%). Most opioid deprescribing interventions targeted hospital to home care transition with mixed results in opioid deprescribing. Further research should consider the implementability of interventions during transitions of care to elucidate the impact of opioid deprescribing interventions across care settings.

Methods of alignment in total knee arthroplasty, systematic review

Introduction

Although total knee arthroplasty (TKA) is a very frequent surgery, one in five patients is not completely satisfied. Mechanical alignment (MA) is the most popular technique for implanting TKA. However, to improve clinical outcomes, new techniques that aim to rebuild the native alignment of the knee have been developed.

Objective

The aim of this study is to perform a systematic review of the available clinical trials and observational studies comparing clinical and radiological outcomes of different methods of alignment (kinematic, anatomic, functional) to MA.

Methods

A systematic review is performed comparing results of patient reported outcome measures (PROMs) questionnaires (WOMAC, OKS, KSS, KOOS, FJS), radiological angles (HKA, mLDFA, MPTA, JLOA, femoral rotation and tibial slope) and range of motion (ROM).

Results

Kinematic and functional alignment show a slight tendency to obtain better PROMs compared to mechanical alignment. Complication rates were not significantly different between groups. Nevertheless, these results are not consistent in every study. Anatomic alignment showed no significant differences compared to mechanical alignment.

Conclusion

Kinematic alignment is an equal or slightly better alternative than mechanical alignment for patients included in this study. However, the difference between methods does not seem to be enough to explain the high percentage of dissatisfied patients. Studies implementing lax inclusion and exclusion criteria would be needed to resemble conditions of patients assisted in daily surgical practice. It would be interesting to study patient's knee phenotypes, to notice if any method of alignment is significantly better for any constitutional deviation.

Impact of change in coronal plane alignment of knee (CPAK) classification on outcomes of robotic-assisted TKA

BACKGROUND

Mechanical alignment with total knee arthroplasty (TKA) has been widely used since the implantation of the first prosthetic knee. Multiple studies have reported 80% patient satisfaction with TKA. However, the reported patients' dissatisfaction is believed to be caused by having to convert different knee alignments to neutral alignments. It is postulated that a change in the CPAK classification of knees leads to patient dissatisfaction. Thus, we hypothesized that a change in CPAK classification with robot-assisted TKA with mechanical alignment does not significantly lead to patient dissatisfaction.

METHODS

We retrospectively analyzed 134 patients who underwent robot-assisted mechanical alignment total knee arthroplasty (MA-TKA) using cementless implants and classified them into CPAK system pre- and post-operatively. One year after TKA surgery, we recorded binary responses to patients' satisfaction with the outcome of surgery and analyzed if a change in CPAK classification is associated with the outcome of surgery.

RESULTS

We found that 125 out of 134 patients (93.28%) were happy with the outcome of surgery. CPAK classification was changed in 116 patients (86.57%) and maintained in 18 patients (13.43%). Our results also showed that 111 (95.7%) out of 116 patients who had a change in CPAK and 14 (77.8%) out of 18 patients who maintained their CPAK post-surgery were happy with the outcome of surgery (OR = 6.3, CI 1.741-25.17, P value = 0.019).

CONCLUSION

We concluded that changing the patient's native joint line and CPAK classification does not significantly change the outcome of surgery in terms of satisfaction. The dissatisfaction rate of 20% as published by previous researchers may be confounded by other reasons and not just due to changes in alignment and joint line.

Definitions and consequences of current alignment techniques and phenotypes in total knee arthroplasty (TKA) - there is no winner yet

Dissatisfaction following total knee arthroplasty (TKA) has been extensively documented and it was attributed to numerous factors. In recent years, significant focus has been directed towards implant alignment and stability as potential causes and solutions to this issue. Surgeons are now exploring a more personalized approach to TKA, recognizing the importance of thoroughly understanding each individual patient's anatomy and functional morphology. A more comprehensive preoperative analysis of alignment and knee morphology is essential to address the unresolved questions in knee arthroplasty effectively. The crucial task of determining the most appropriate alignment strategy for each patient arises, given the substantial variability in bone resection resulting from the interplay of phenotype and the alignment strategy chosen. This review aims to comprehensively present the definitions of different alignment techniques in all planes and discuss the consequences dependent on knee phenotypes.Level of evidence V.

Current Concepts in Alignment in Total Knee Arthroplasty

BACKGROUND

In an effort to increase satisfaction among total knee arthroplasty (TKA) patients, emphasis has been placed on implant positioning and limb alignment. Traditionally, the aim for TKA has been to achieve a neutral mechanical alignment (MA) to maximize implant longevity. However, with the recent spike in interest in individualized alignment techniques and with the advent of new technologies, surgeons are slowly evolving away from classical MA.

METHODS

This review elucidates the differences in alignment techniques for TKA, describes the concept of knee phenotypes, summarizes comparative studies between MA and individualized alignment, and provides a simple way to incorporate the latter into surgeons' practice.

RESULTS

In order to manage patients by applying these strategies in day-to-day practice, a basic understanding of the aforementioned concepts is essential. Transition to an individualized alignment technique should be done gradually with caution in a stepwise approach.

CONCLUSION

Alignment and implant positioning are now at the heart of the debate and surgeons are investigating a more personalized approach to TKA.