Impact of total knee replacement practice: cost effectiveness analysis of data from the Osteoarthritis Initiative

Pre-operative EQ-5D-5L is a strong predictor of meaningful improvement in quality of life following primary total knee arthroplasty

INTRODUCTION

Predicting which patients will get meaningful benefit from total knee arthroplasty remains a challenge. Our aim was to assess if pre-operative quality of life (EuroQol 5-Dimension, 5-Level instrument; EQ-5D-5L) can predict the likelihood of a patient achieving post-operative improvement in patient-reported outcome measures (PROMS) following total knee arthroplasty to a level of minimum clinically-important difference (MCID).

MATERIALS AND METHODS

This was a retrospective analysis of a prospective cohort of total knee arthroplasty patients. EQ-5D-5L and Oxford Knee Scores (OKS) were recorded pre-operatively, 6 months and 2 years post-operatively. The primary outcome measure was achievement of MCID in EQ-5D-5L at 2 years. Multivariable analysis through multiple logistic regression was performed to assess for independent predictors of MCID in EQ-5D-5L, OKS and re-operation at 2 years.

RESULTS

400 patients were included, with 57% female and a mean age of 66 years. Pre-operative EQ-5D-5L was the only strong predictor of post-operative EQ-5D-5L MCID (OR: 0.016, CI: 0.004 to 0.06), when adjusted for age, gender, BMI, ASA, smoking status and surgeon grade. The optimal pre-operative EQ-5D-5L threshold was found to be 0.53 by Youden's index, with a sensitivity of 70% and specificity of 73%.

CONCLUSIONS

Pre-operative quality of life as measured by EQ-5D-5L is a strong independent predictor of reaching MCID in EQ-5D-5L following total knee arthroplasty. Those with worse EQ-5D-5L are more likely to gain meaningful benefit from knee arthroplasty.

The economics of a national anterior cruciate ligament injury prevention program for amateur football players: a Markov model analysis

OBJECTIVES

To estimate the long term cost savings, return on investment, and gain in quality-adjusted life years (QALYs) that could be achieved by a national anterior cruciate ligament (ACL) injury prevention program for amateur football (soccer) players in Australia.

STUDY DESIGN

Markov model decision analysis.

SETTING, PARTICIPANTS

Two hypothetical scenarios including all amateur football players in Australia (340 253 players): no intervention, and a national ACL injury prevention program. Transitions between health states, including ACL rupture, meniscal injury, knee osteoarthritis, and total knee replacement were made in one-year cycles over 35 years from a societal perspective.

MAIN OUTCOME MEASURES

Cost savings, return on investment, and QALY gain achieved in the prevention program scenario relative to control scenario, by age group (10-17, 18-34, 35 years or older) and gender.

SECONDARY OUTCOMES

incidence of ACL rupture, knee osteoarthritis, total knee replacement, and total knee replacement revision.

RESULTS

The total mean cost of an ACL injury was estimated to be $30 665. The national injury prevention program was projected to save $52 539 751 in medical and societal costs caused by ACL ruptures in amateur footballers over 35 years; the estimated return on each dollar invested in the program was $3.51. Over this period, the number of players with ruptured ACLs could be reduced by 4385 (9%), the number of knee osteoarthritis cases by 780 (8.1%), and the number of total knee replacements by 121 (8.1%); 445 QALYs were gained.

CONCLUSION

Our findings support investing in a national, evidence-based program for the primary prevention of ACL injuries in amateur football players.

Advancements in pH-Responsive nanoparticles for osteoarthritis treatment: Opportunities and challenges

Osteoarthritis (OA) is a degenerative disease linked to aging and obesity. The global aging population has led to an increasing number of OA patients, imposing a significant economic burden on society. Traditional drugs treatment methods often fail to achieve satisfactory outcomes. With the rapid advancement of nanomaterial delivery systems, numerous studies have focused on utilizing nanomaterials as carriers to achieve efficient OA treatment by effectively loading and delivering bioactive ingredients (e.g., drugs, nucleic acids) tailored to the unique pathological conditions, such as the weakly acidic microenvironment of synovial fluid in OA patients. This review highlights the latest advancements in the use of pH-responsive nanoparticles for OA treatment, emphasizing the principle of targeted drug delivery leveraging the acidic microenvironment of inflamed joints. It further discusses the composition, synthesis, response mechanism, target selection, application, and recent research findings of nanoparticles, while also addressing the challenges and future directions in this promising field.

Shorter length of stay and significant cost savings with ambulatory surgery primary unilateral total knee arthroplasty in Asians using enhanced recovery protocols

Introduction

Enhanced recovery after surgery (ERAS) in total knee arthroplasty (TKA) has reduced the length of stay (LOS) and cost of TKA in the Western population. Asians had been identified to be at higher odds of non-home discharge following TKA due to cultural differences. The efficacy of ERAS in TKA for Asian patients is less known. We aimed to investigate the efficacy of ERAS in reducing the LOS, transition to ambulatory surgery, improving home discharges, and reducing cost in an Asian population following TKA.

Methods

Retrospective analysis was performed on 634 TKA patients in 2017 (pre- ERAS) and 584 TKA patients who had undergone ERAS in 2022 in a tertiary hospital.

Results

Patients in 2022 (ERAS) were older (69 ± 7 vs. 68 ± 7 years old, p < 0.001) and had a higher proportion of patients with poorer function (p < 0.001). The LOS reduced from 5.4 days (95% CI:5.2-5.6) to 2.9 days (95% CI:2.7-3.2) (p < 0.001) with about 49 % of patients transitioning to ambulatory surgery and having a LOS of 1.4 days (95 %CI:1.3-1.5). The proportion of patients being discharged home in 2022 (78.9 %) was higher compared to 2017 (62.2 %) (p < 0.001). This saved the hospital 1817.4 inpatient ward bed days, which translated to S$2,124,540.60 of cost saving in a year, and up to S$2397.28 for the individual patient.

Conclusion

ERAS after TKA was able to safely achieve LOS comparable to the western population and allowed transition to ambulatory knee replacement in the Asian population. Consequently, this led to higher proportion of home discharges and achieved significant cost saving and hospital bed days.

Casticin ameliorates osteoarthritic cartilage damage in rats through PI3K/AKT/HIF-1α signaling

Knee osteoarthritis (KOA) is a chronic, disabling knee joint lesion in which degeneration and defects in articular cartilage are the most important features. Casticin (CAS) is a flavonoid extracted from the Chinese herb Vitex species that has anti-inflammatory and antitumor effects. The aim of this study was to investigate the therapeutic and mechanistic effects of CAS on cartilage damage in KOA. A KOA rat model was established by anterior cruciate ligament transection (ACLT), and cartilage morphological changes were assessed by histological analysis and micro-CT scans. Subsequently, chondrocytes were treated with 10 ng/mL IL-1β to establish an OA model. CCK-8 assays and EdU assays were performed to assess the viability of CAS-treated chondrocytes. Western blotting, flow cytometry and Hoechst 33342/PI Double Stain were used to detect chondrocyte apoptosis. Western blotting, qRT‒PCR and ELISA were used to detect changes in inflammatory mediators. In addition, cartilage matrix-related indices were detected by Western blotting, qRT‒PCR and immunofluorescence (IF) analysis. Immunohistochemistry (IHC) and Western blotting were performed to detect the expression of p-PI3K, p-AKT and HIF-1α in vivo and in vitro. Micro-CT, pathological sections and related scores showed that CAS improved the alterations in bony structures and reduced cartilage damage and osteophyte formation in the ACLT model. In vivo, CAS attenuated IL-1β-induced cartilage matrix degradation, apoptosis and the inflammatory response. In addition, CAS inhibited the expression of the PI3K/AKT/HIF-1α signaling pathway in the ACLT animal model and IL-1β cell model. CAS may ameliorate cartilage damage in OA by inhibiting the PI3K/AKT/HIF-1α signaling pathway, suggesting that CAS is a potential strategy for the treatment of OA.

What Is the Safest Intersurgical Interval between Staged Bilateral Total Knee Arthroplasty? A Nationwide Analysis of 20,279 Patients

In staged bilateral total knee arthroplasty (BTKA), the intersurgical time is yet to be determined. This study aimed to (1) test for differences in in-hospital metrics between the index and contralateral TKA and (2) determine the safest intersurgical time interval to minimize adverse outcomes after the contralateral surgery. The National Readmissions Database was queried for patients who received staged BTKA (2016-2017). A total of 20,279 patients were included. Demographics, comorbidities, baseline determinants, and intersurgical time between index and contralateral TKAs (≤ 3 month, 4-6 months, 7-9 months, and 10-12 months intervals) were captured. Outcomes included healthcare utilization (length of stay [LOS] and nonhome discharge), in-hospital costs, and in-hospital complications. Outcomes were compared between index versus contralateral surgeries and among contralateral surgeries of various intersurgical intervals. Contralateral surgeries had shorter LOS (2.2 ± 1.9 vs. 2.4 ± 2.0 days; p < 0.001), lower nonhome discharge (n = 2692[13.2%] vs. n = 2963[14.7%]; p = 0.001), and in-hospital costs ($16,476 ± $7,404 vs. 16,774 ± $9,621; p < 0.001), but similar rates of nonmechanical (p = 0.40) complications compared with index TKA. Multivariable regression demonstrated that intersurgical time was not associated with nonmechanical complications or transfusion, or 30-day readmission (p > 0.05, each). Compared with the less than or equal to 3-month interval, the 4 to 6-month interval exhibited highest odds ratio (OR) of any infection (OR: 1.81; 95% confidence interval [CI]: [1.13-2.88]; p = 0.013), urinary tract infection (OR:1.81, 95%CI: [1.13-2.90]; p = 0.014), and any-cardiac complications (OR:1.17; 95%CI: [1.01-1.35]; p = 0.037). Patients in the 10-12-month cohort had lowest odds of posthemorrhagic anemia (OR: 0.84; 95% CI: [0.72-0.98]; p = 0.03). Overall, the second surgery of a staged BTKA has lower healthcare utilization despite similar complication rates. While patients in the 10 to 12-month intersurgical interval had the most favorable overall safety profile, no single interval exhibited consistently lower complications for all measured outcomes. Special care pathways should be optimized to care for patients undergoing staged BTKA.

Searching for Essential Genes and Targeted Drugs Common to Breast Cancer and Osteoarthritis

BACKGROUND

It is documented that osteoarthritis can promote the progression of breast cancer (BC).

OBJECTIVE

This study aims to search for the essential genes associated with breast cancer (BC) and osteoarthritis (OA), explore the relationship between epithelial-mesenchymal transition (EMT)- related genes and the two diseases, and identify the candidate drugs.

METHODS

The genes related to both BC and OA were determined by text mining. Protein-protein Interaction (PPI) analysis was carried out, and as a result, the exported genes were found to be related to EMT. PPI and the correlation of mRNA of these genes were also analyzed. Different kinds of enrichment analyses were performed on these genes. A prognostic analysis was performed on these genes for examining their expression levels at different pathological stages, in different tissues, and in different immune cells. Drug-gene interaction database was employed for potential drug discovery.

RESULTS

A total number of 1422 genes were identified as common to BC and OA and 58 genes were found to be related to EMT. We found that HDAC2 and TGFBR1 were significantly poor in overall survival. High expression of HDAC2 plays a vital role in the increase of pathological stages. Four immune cells might play a role in this process. Fifty-seven drugs were identified that could potentially have therapeutic effects.

CONCLUSION

EMT may be one of the mechanisms by which OA affects BC. Using the drugs can have potential therapeutic effects, which may benefit patients with both diseases and broaden the indications for drug use.

Metformin for knee osteoarthritis with obesity: study protocol for a randomised, double-blind, placebo-controlled trial

INTRODUCTION

Over half of the populations with knee osteoarthritis (OA) have obesity. These individuals have many other shared metabolic risk factors. Metformin is a safe, inexpensive, well-tolerated drug that has pleiotropic effects, including structural protection, anti-inflammatory and analgesic effects in OA, specifically the knee. The aim of this randomised, double-blind, placebo-controlled trial is to determine whether metformin reduces knee pain over 6 months in individuals with symptomatic knee OA who are overweight or obese.

METHODS AND ANALYSIS

One hundred and two participants with symptomatic knee OA and overweight or obesity will be recruited from the community in Melbourne, Australia, and randomly allocated in a 1:1 ratio to receive either metformin 2 g or identical placebo daily for 6 months. The primary outcome is reduction of knee pain [assessed by 100 mm Visual Analogue Scale (VAS)] at 6 months. The secondary outcomes are OMERACT-OARSI (Outcome Measures in Rheumatology-Osteoarthritis Research Society International) responder criteria [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, function and participant's global assessment (VAS)] at 6 months; change in knee pain, stiffness, function using WOMAC at 6 months and quality of life at 6 months. Adverse events will be recorded. The primary analysis will be by intention to treat, including all participants in their randomised groups.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the Alfred Hospital Ethics Committee (708/20) and Monash University Human Research Ethics Committee (28498). Written informed consent will be obtained from all the participants. The findings will be disseminated through peer-review publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12621000710820 .

Perioperative insomnia trajectories and functional outcomes after total knee arthroplasty

ABSTRACT

Longitudinal total knee arthroplasty (TKA) studies indicate that a substantial percentage of patients continue to experience clinically significant pain and functional impairment after surgery. Insomnia has been associated with poorer surgical outcomes; however, previous work has largely focused on long-term postsurgical insomnia. This study builds on previous work by examining sleep and pain outcomes about perioperative insomnia trajectories. Insomnia symptoms (using the Insomnia Severity Index) during the acute perioperative period (2 weeks pre-TKA to 6 weeks post-TKA) were used to classify participants into perioperative insomnia trajectories: (1) No Insomnia (ISI < 8), (2) New Insomnia (baseline < 8; postoperative ≥ 8 or ≥6-point increase), (3) Improved Insomnia (baseline ≥ 8, postoperative < 8 or ≥6-point decrease), and (4) Persistent Insomnia (ISI ≥ 8). Insomnia, pain, and physical functioning were assessed in participants with knee osteoarthritis (n = 173; M age = 65 ± 8.3, 57.8% female) at 5 time points: 2 weeks pre-TKA, post-TKA: 6 weeks, 3 months, 6 months, and 12 months. Significant main effects were seen for insomnia trajectory and time, and trajectory-by-time interactions for postoperative insomnia, pain severity, and physical functioning ( P' s < 0.05). The Persistent Insomnia trajectory had the worst postoperative pain at all follow-ups and marked insomnia and physical functioning impairment post-TKA ( P' s < 0.05). The New Insomnia trajectory had notable long-term insomnia (6 weeks to 6 months) and acute (6 weeks) postoperative pain and physical functioning ( P' s < 0.05). Findings indicated a significant relationship between perioperative insomnia trajectory and postoperative outcomes. Results of this study suggest that targeting presurgical insomnia and preventing the development of acute postoperative insomnia may improve long-term postoperative outcomes, with an emphasis on persistent perioperative insomnia due to poorer associated outcomes.

Assessing the Mortality Rate After Primary Total Knee Arthroplasty: An Observational Study to Inform Future Economic Analysis

BACKGROUND

Previous research has focused on the perioperative or short-term (<1 year) mortality rate of total knee arthroplasty (TKA), leaving the long-term (>1 year) mortality rate unresolved. In this study, we calculated the mortality rate up to 15 years after primary TKA.

METHODS

Data from the New Zealand Joint Registry from April 1998 to December 2021 were analyzed. Patients aged 45 years or older who underwent TKA for osteoarthritis were included. Mortality data were linked with national records from births, deaths, and marriages. To determine the expected mortality rates in the general population, age-sex-specific life tables from statistics New Zealand were used. Mortality rate was presented as standardized mortality ratios (SMRs) - a comparison of relative mortality rate between the TKA and general populations. In total, 98,156 patients with a median follow-up of 7.25 years (range, 0.00 to 23.74) were included.

RESULTS

Over the entire follow-up period, 22,938 patients (23.4%) had died. The overall SMR for the TKA cohort was 1.08 (95% confidence interval (CI): 1.06 to 1.09), suggesting that TKA patients have an 8% higher mortality rate compared to the general population. However, a reduction in short-term mortality rate was observed for TKA patients up to 5 years post TKA (SMR 5 years post TKA; 0.59 95% CI: 0.57 to 0.60]). On the contrary, a significantly increased long-term mortality rate was observed in TKA patients with greater than 11 years of follow-up, particularly in men over the age of 75 years (SMR 11 to 15 years post TKA for males ≥ 75 years; 3.13 [95% CI: 2.95 to 3.31]).

CONCLUSION

The results suggest a reduction in short-term mortality rate for patients who undergo primary TKA. However, there is an increased long-term mortality rate particularly in men over the age of 75 years. Importantly, the mortality rates observed in this study cannot be causally attributed to TKA alone.

NEAT1-mediated miR-150-5p downregulation regulates b-catenin expression in OA chondrocytes

We investigated the role of miR-150-5p in osteoarthritic (OA) chondrocytes, as well as the possible regulatory role of long non-coding RNAs (lncRNAs) in miR-150-5p expression. TargetScan, StarBase, DIANA-LncBase, and Open Targets databases were used to predict miR-150-5p target genes, lncRNAs/miR-150-5p interactions, and OA-related genes. Protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). Gene ontology (GO) and pathway analysis were performed using Enrichr database. A publicly available RNA-seq dataset was retrieved to identify differentially expressed lncRNAs in damaged vs intact cartilage. We re-analyzed the retrieved RNA-seq data and revealed 177 differentially expressed lncRNAs in damage vs intact cartilage, including Nuclear Paraspeckle Assembly Transcript 1(NEAT1). MiR-150-5p, NEAT1, b-catenin, matrix metallopeptidase 13 (MMP-13), and ADAM metallopeptidase with thrombospondin type 1 motif 5 (ADAMTS-5) expressions were assessed by reverse transcription-quantitative PCR (RT-qPCR) and western blot assay. Knockout and transfection experiments were conducted to investigate the role of NEAT1/miR-150-5p/b-catenin in cartilage degradation. Bioinformatics analysis revealed that b-catenin was an OA-related miR-150-5p target. MiR-150-5p overexpression in OA chondrocytes resulted in decreased expression of b-catenin, as well as MMP-13 and ADAMTS-5, both being Wnt/b-catenin downstream target genes. NEAT1/miR-150-5p interaction was predicted by bioinformatics analysis, while NEAT1 knockout led to increased expression of miR-150-5p in OA chondrocytes. Moreover, inhibition of miR-150-5p reversed the repressive effects of NEAT1 silencing in b-catenin expression in OA chondrocytes. Our results support a possible catabolic role of NEAT1/miR-150-5p interaction in OA progression by regulating b-catenin expression.

Application strategy of finite element analysis in artificial knee arthroplasty

Artificial knee arthroplasty, as the most effective method for the treatment of end-stage joint diseases such as knee osteoarthritis and rheumatoid arthritis, is widely used in the field of joint surgery. At present, Finite element analysis (FEA) has been widely used in artificial knee replacement biomechanical research. This review presents the current hotspots for the application of FEA in the field of artificial knee replacement by reviewing the existing research literature and, by comparison, summarizes guidance and recommendations for artificial knee replacement surgery. We believe that lower contact stress can produce less wear and complications when components move against each other, in the process of total knee arthroplasty (TKA), mobile-bearing prostheses reduce the contact surface stress of the tibial-femoral joint compared with fixed-bearing prostheses, thus reducing the wear of the polyethylene insert. Compared with mechanical alignment, kinematic alignment reduces the maximum stress and maximum strain of the femoral component and polyethylene insert in TKA, and the lower stress reduces the wear of the joint contact surface and prolongs the life of the prosthesis. In the unicompartmental knee arthroplasty (UKA), the femoral and tibial components of mobile-bearing prostheses have better conformity, which can reduce the wear of the components, while local stress concentration caused by excessive overconformity of fixed-bearing prostheses should be avoided in UKA to prevent accelerated wear of the components, the mobile-bearing prosthesis maintained in the coronal position from 4° varus to 4° valgus and the fixed-bearing prosthesis implanted in the neutral position (0°) are recommended. In revision total knee arthroplasty (RTKA), the stem implant design should maintain the best balance between preserving bone and reducing stress around the prosthesis after implantation. Compared with cemented stems, cementless press-fit femoral stems show higher fretting, for tibial plateau bone defects, porous metal blocks are more effective in stress dispersion. Finally, compared with traditional mechanical research methods, FEA methods can yield relatively accurate simulations, which could compensate for the deficiencies of traditional mechanics in knee joint research. Thus, FEA has great potential for applications in the field of medicine.

Wnt signalling in the articular cartilage: A matter of balance

Degradation of the articular cartilage is a hallmark of osteoarthritis, a progressive and chronic musculoskeletal condition, affecting millions of people worldwide. The activation of several signalling cascades is altered during disease development: among them, the Wnt signalling plays a pivotal role in the maintenance of tissue homeostasis. Increasing evidence is showing that its activation needs to be maintained within a certain range to avoid the triggering of degenerative mechanisms. In this review, we summarise our current knowledge about how a balanced activation of the Wnt signalling is maintained in the articular cartilage, with a particular focus on receptor-mediated mechanisms.

What is the Value of a Balanced Total Knee Arthroplasty? Getting it Right the First Time

INTRODUCTION

Instability is a leading cause of early failure following total knee arthroplasty. Enabling technologies can improve accuracy, but their clinical value remains undetermined. The purpose of this study was to determine the value of achieving a balanced knee joint at the time of TKA.

METHODS

A Markov model was developed to determine the value from reduced revisions and improved outcomes associated with TKA joint balance. Patients were modelled for the first 5 years following TKA. The threshold to determine cost-effectiveness was set at an Incremental Cost Effectiveness Ratio (ICER) of $50,000/quality-adjusted life year (QALY). A sensitivity analysis was performed to evaluate the influence of QALY improvement (ΔQALY) and Revision Rate Reduction (ΔRevision) on additional value generated compared to a conventional TKA cohort. The impact of each variable was evaluated by iterating over a range of ΔQALY (0 to 0.046) and ΔRevision (0 to 30%) and calculating the value generated while satisfying the ICER threshold. Finally, the impact of surgeon volume on these outcomes were analyzed.

RESULTS

The total value of a balanced knee for the first 5 years was $8,750, $6,575, and $4,417 per case, for low, medium, and high-volume surgeons, respectively. Change in QALY accounted for greater than 90% of the value gain with a reduction in revisions making up the rest in all scenarios. The economic contribution of revision reduction was relatively constant regardless of surgeon volume ($500/case).

CONCLUSIONS

Achieving a balanced knee had the greatest impact on QALY improvement over early revision rate. These results can help assign value to enabling technologies with joint balancing capabilities.

Advanced glycation end-product accumulation differs by location and sex in aged osteoarthritic human menisci

OBJECTIVE

There is a clear link between increasing age and meniscus degeneration, leading to increased injury, osteoarthritis (OA) progression, and often total knee replacement. Advanced glycation end-products (AGEs) are non-enzymatic crosslinks and adducts that accumulate in collagen with age, altering tissue mechanics and cell function, ultimately leading to increased injury and inflammation. AGEs, both fluorescent and non-fluorescent, play a central role in age-related degradation of tissues throughout the body; however, little is known about their role in meniscus degeneration. The objective of this study was to characterize changes in aged OA menisci, specifically evaluating zonal AGE accumulation, to gain a better understanding of changes that may lead to age-related meniscal degeneration.

METHOD

Deidentified human menisci (N = 48, 52-84 years old) were obtained from subjects undergoing total knee replacement. Changes in extracellular matrix (ECM) were assessed by gross morphology, confocal analysis, and biochemical assays. Deoxyribonucleic acid (DNA), glycosaminoglycan (GAG), collagen, and AGE accumulation were compared with patient age, zonal region, and patient sex.

RESULTS

There were minimal changes in DNA, GAG, and collagen concentration with age or zone. However, collagen fraying and AGEs increased with age, with more AGEs accumulating in the meniscal horns compared to the central body and in male menisci compared to females.

CONCLUSIONS

Overall, this work provides greater insights into regional changes that occur in human menisci with age and OA. These results suggest AGEs may play a role in the degeneration of the meniscus, with AGEs being a possible target to reduce age-related tears, degeneration, and OA progression.

LncRNA MEG3-TRPV1 signaling regulates chronic inflammatory pain in rats

Osteoarthritis (OA) is a common osteoarthropathy with chronic inflammatory pain as the core symptom in middle-aged and elderly people. LncRNA MEG3 (Maternally expressed gene 3) is involved in the development of OA via regulation of angiogenesis, which causes the activation and overexpression of transient receptor potential vanilloid type-1 (TRPV1). In this study, we investigated the mechanism of MEG3-TRPV1 signaling in chronic inflammatory pain (CIP) of rat model. Chronic inflammatory pain was modeled using subcutaneous microinjection of complete Freund's adjuvant (CFA) into the left hind paw of rats. We showed that TRPV1 mRNA and protein were significantly increased, while MEG3 mRNA was significantly decreased, in the DRG and SDH of CFA-induced rats. In addition, intrathecal injection of MEG3-overexpressing lentivirus significantly downregulated TRPV1 expression and alleviated chronic inflammatory pain in CFA-induced rats. Treatment with a TRPV1 antagonist also significantly relieved chronic inflammatory pain in CFA-induced rats. In general, our results reveal that MEG3 alleviates chronic inflammatory pain by downregulating TRPV1 expression. These findings may provide new therapeutic targets in the treatment of patients with OA.

Decrementally cost-effective health technologies in non-inferiority studies: A systematic review

Background: HTA guidance has generally been driven by situations where innovative and usually more expensive technologies are compared to the prevailing standards of care. Cheaper and less efficacious interventions have received scarce attention, although strategies with minimal individual efficacy losses might produce collective health gains when savings are redistributed. Purpose: This systematic review of health economic evaluations identified interventions that are both cost and outcome reducing to procure a list of candidate decrementally cost-effective technologies. Data Sources: English language searches were performed in PubMed, EMBASE and ClinicalTrials.gov covering 2005 to September 2021. Study Selection: Full economic evaluations reporting in English decrementally cost-effective health technologies based on RCT data, modelling or mixed methods. Data Synthesis: After filtering 4,975 studies found through the systematic database search, 107 decrementally cost-effective health technologies (HTs) were identified. Nearly a third were services (n = 29) and similarly for drugs (n = 31). For over half of the studies (n = 54) health outcomes were measured in QALYs and the cost-utility ratios varied from €140 to €5 million saved per QALY lost, albeit with time horizons varying from 4 days of follow-up to lifetime extrapolations. Less than a quarter of the studies were carried out from the societal perspective. Limitations: Despite including ClinicalTrials.gov as data source, unpublished studies may have been missed. Conclusions: Our results show a growth in recent years in the number of economic publications demonstrating decrementally cost-effective HTs. Economic tools are needed to facilitate the adoption of such HTs by policy-makers at the national level to maximise health outcomes at the population level. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=95504, identifier CRD42018095504.

Ultrasound-guided dry needling versus traditional dry needling for patients with knee osteoarthritis: A double-blind randomized controlled trial

Objective

To compare the effect of ultrasound (US)-guided dry needling (DN) with traditional DN in the treatment of pain and dysfunction for patients with knee osteoarthritis (KOA).

Design

A double-blind, randomized controlled trial.

Methods

Patients (25 male and 65 female), age 50–80 years diagnosed with KOA were recruited and randomly assigned to one of three groups in a 1:1:1 ratio for intervention: real US-guided DN with exercise therapy (G1), placebo US-guided DN with exercise therapy (G2), and exercise therapy solely (G3). G1 and G2 were blinded to the application of real or placebo US guidance by turning the monitor of US imaging out-of-view from participants’ vantage points. The effectiveness of blinding was evaluated by asking the participants whether they had received real-US guided DN. The responses were assessed by Chi-square test. Visual Analogue Scale (VAS), Knee injury, and Osteoarthritis Outcome Score (KOOS) subscales (KOOS-pain, KOOS-symptoms, KOOS-quality-of-life (QoL)) were collected at baseline, 4 weeks, and 8 weeks by a blinded assessor. Data were analyzed by mixed model analysis of variance (ANOVA) with Bonferroni correction.

Results

Eighty-four participants (61.26±5.57 years) completed the study. G1 achieved significant improvement in VAS at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = -15.61, 95% CI [-25.49, -5.51], p = 0.001; G1 vs. G3: MD = -19.90, 95% CI [-29.71, -10.08], p< 0.001). G1 achieved significant improvement in KOOS-pain at 8 weeks compared to G2 and G3 (G1 vs. G2: MD = 9.76, 95% CI [2.38, 17.14], p = 0.006; G1 vs. G3: MD = 9.48, 95% CI [2.31, 16.66], p = 0.010). KOOS-symptoms and KOOS-QoL were not statistically significant between groups. G2 had no significant difference of the perceptions as G1 with p = 0.128. G2 were successfully blinded to placebo US-guided DN.

Conclusion

US-guided DN with exercise therapy may be more effective than traditional DN with exercise therapy or exercise therapy alone in reduce pain of KOA.

Cost-utility analysis of total knee arthroplasty alone and in comparison with post-surgical rehabilitation and conservative treatment in the Republic of Kazakhstan

BACKGROUND

Despite ample international knowledge on cost-effectiveness of total knee arthroplasty (TKA), it has never been a subject of investigation in Kazakhstan or other post-Soviet economies. Our study aimed to carry-out the cost-utility analysis of TKA alone and in comparison with post-surgical rehabilitation and conservative treatment at health care facilities of Kazakhstan.

METHODS

Two hundred and forty four patients with knee osteoarthritis (KOA) who underwent TKA in orthopedic departments of Almaty, Nur-Sultan and Semey hospitals between January 1, 2019 and September 30, 2019 were followed-up for 12 months. The health-related quality of life was measured by the EQ-5D utility and Western Ontario and McMaster Universities Osteoarthritis Index was used to measure the patients' health status. The costs were estimated from the view of health care provider. We calculated the cost per QALY, the Cost-Utility Ratio and the Incremental Cost-Effectiveness Ratio.

RESULTS

At the time of 12-month follow-up patients who received TKA alone or with the course of rehabilitation showed benefit over patients from the group of conservative treatment in terms of overall health status. Mean QALY gained at 12 months constituted 1.66 for the group that received TKA with rehabilitation, 1.48 for the group that received TKA alone and 0.24 for the group that received conservative treatment. Mean cost per QALY gained was USD 30 795.75 for KOA patients under conservative treatment, USD 6 323.69 for KOA patients subjected to TKA and USD 2 670.32 for KOA patients with rehabilitation course after TKA.

CONCLUSION

Both TKA and TKA with rehabilitation could be considered as highly cost-effective interventions. The data obtained could be of interest for policy makers, medical professionals and KOA patients.

Chondroitin sulfate microspheres anchored with drug-loaded liposomes play a dual antioxidant role in the treatment of osteoarthritis

Reactive oxygen species (ROS) play a critical role in the pathogenesis of osteoarthritis. The injection of a single antioxidant drug is characterized by low drug utilization and short residence time in the articular cavity, limiting the therapeutic effect of antioxidant drugs on osteoarthritis. Currently, the drug circulation half-life can be extended using delivery vehicles such as liposomes and microspheres, which are widely used to treat diseases. In addition, the composite carriers of liposomes and hydrogel microspheres can combine the advantages of different material forms and show stronger plasticity and flexibility than traditional single carriers, which are expected to become new local drug delivery systems. Chondroitin sulfate, a sulfated glycosaminoglycan commonly found in native cartilage, has good antioxidant properties and degradability and is used to develop an injectable chondroitin sulfate hydrogel by covalent modification with photo-cross-linkable methacryloyl groups (ChsMA). Herein, ChsMA microgels anchored with liquiritin (LQ)-loaded liposomes (ChsMA@Lipo) were developed to delay the progression of osteoarthritis by dual antioxidation. On the one hand, the antioxidant drug LQ wrapped in ChsMA@Lipo microgels exhibits significant sustained-release kinetics due to the double obstruction of the lipid membrane and the hydrogel matrix network. On the other hand, ChsMA can eliminate ROS through degradation into chondroitin sulfate monomers by enzymes in vivo. Therefore, ChsMA@Lipo, as a degradable and dual antioxidant drug delivery platform, is a promising option for osteoarthritis treatment. STATEMENT OF SIGNIFICANCE: Compared with the traditional single carrier, the composite carriers of hydrogel microspheres and liposome can complement the advantages of different materials, which shows stronger plasticity and flexibility, and is expected to become a new and efficient drug delivery system. ChsMA@Lipo not only attenuates IL-1β-induced ECM degradation in chondrocytes but also inhibits the M1 macrophages polarization and the inflammasome activation. The obtained ChsMA@Lipo alleviates the progression of osteoarthritis in vivo, which is promising for osteoarthritis treatment.

Understanding Health Economics in Joint Replacement Surgery

The number of arthroplasty procedures has been rising at a significant rate, contributing to a notable portion of the nation's health care spending. This growth has contributed to an increase in the number of health care economic studies in the field of adult reconstruction surgery. Although these articles are filled with important information, they can be difficult to understand without a background in business or economics. The goal of this review is to define the common terminology used in health care economic studies, assess their value and benefit in the context of total joint arthroplasty, and highlight shortcomings in the current literature. [Orthopedics. 2022;45(4):e174-e182.].

Metformin use and the risk of total knee replacement among diabetic patients: a propensity-score-matched retrospective cohort study

Metformin has been shown to modulate meta-inflammation, an important pathogenesis in knee osteoarthritis (OA). The study aimed to test the association between regular metformin use with total knee replacement (TKR) in patients with diabetes. This is a retrospective study with electronic records retrieved in Hong Kong public primary care. Patients with diabetes aged ≥ 45 who visited during 2007 to 2010, were followed up for a four-year period from 2011 to 2014 to determine the incidence of TKR. Propensity score matching based on age, sex, co-medications and chronic conditions was conducted to adjust for confounding. Cox regression was implemented to examine the association between metformin use and TKR. In total, 196,930 patients were eligible and 93,330 regular metformin users (defined as ≥ 4 prescriptions over the previous year) and non-users were matched. Among 46,665 regular users, 184 TKRs were conducted, 17.1% fewer than that among non-users. Cox regression showed that regular metformin users had a 19%-lower hazard of TKR [hazard ratio (HR) = 0.81, 95% confidence interval: 0.67 to 0.98, P = 0.033], with a dose–response relationship. Findings suggest a potential protective effect of metformin on knee OA progression and later TKR incidence among diabetic patients.

Effect of the knee replacement surgery on activity level based on ActivPAL: a systematic review and meta-analysis study

BACKGROUND

The knee replacement (KR) surgery aims to restore the activity level and reduce the risk of experiencing disabilities. The outcomes of this surgery are evaluated mainly with subjective tools or low validity objective tools. However, the effect of the surgery on activity level using high validity objective accelerometer is still in question.

METHODS

A systematic review and meta-analysis were conducted to evaluate the benefit of KR surgery alone to enhance physical activity recommendations based on high validity accelerometer. Two independent reviewers evaluated five electronic databases (Cochrane-Central-Register-of-Controlled Trials, EMBASE, PubMed, Web of Science, and Scopus) to find relative studies between January 2000 and October 2021. The quality assessments and risk of bias assessments were examined.

RESULTS

Three articles were included with 202 participants (86 males, 116 females), with an average age of 64 years and an average 32 kg/m2 body mass index. The results found that the number of steps was significantly improved up to 36.35 and 45.5% after 6-months and 1-year of the surgery, respectively. However, these changes did not meet the recommended activity level guideline and could be related to the patients' health status and their activity level before the surgery. No significant changes were seen in sedentary time, standing time, and upright time after 6-months and 1-year follow-ups. Heterogeneity among studies was low to moderate (0-63%).

CONCLUSION

Knee replacement surgery is an effective treatment for improving patients' quality of life with severe knee injuries. However, various factors impact the success of surgical and achieving maximum benefit of the surgery. One factor, sedentary time, can be reduced by implementing pre-and post-surgery exercise or physical activity recommendations. Further studies are needed to understand the benefit of surgery with or without rehabilitation assessed using high validity monitors.

Effects of acupuncture at acupoints with lower versus higher pain threshold for knee osteoarthritis: a multicenter randomized controlled trial

BACKGROUND

The acupoint selections impact the effects of acupuncture, and preliminary evidence showed potential connection between pain threshold (PT) and acupuncture response. This study examined whether acupuncture at acupoints with lower PT versus higher PT would yield different effects in patients with knee osteoarthritis (KOA).

METHODS

In this multicenter randomized clinical trial, patients were randomly assigned (1:1:1) to receive acupuncture at acupoints with lower PT (LPT group), acupuncture at acupoints with higher PT (HPT group), and no acupuncture (waiting-list group). PT was measured with electronic von Frey detector. The primary outcome was the change in WOMAC total score from baseline to 16 weeks, and the secondary outcomes were SF-12 score, and active knee range of motion (ROM). Intention-to-treat analysis was conducted with linear mixed-effect model.

RESULTS

Among 666 randomized patients, 625 (93.84%) completed the study. From baseline to 16 weeks, patients in the LPT group versus HPT group had similar effects in reducing WOMAC total score (adjusted mean difference (MD) 2.21, 95% confidence interval (CI) -2.51 to 6.92, P = 0.36), while a greater reduction in WOMAC total score was observed in LPT group (-9.77, 95% CI -14.47 to -5.07, P < 0.001) and HPT group (-11.97, 95% CI -16.71 to -7.24, P < 0.001) compared with waiting-list group. There were no differences in SF-12 score and knee ROM between LPT versus HPT groups.

CONCLUSION

Our findings found that the effects of acupuncture at acupoints with lower versus higher PT were similar, both were effective for patients with KOA.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT03299439. Registered 3 October 2017, https://clinicaltrials.gov/ct2/show/NCT03299439.

Risk assessment for hip and knee osteoarthritis using polygenic risk scores

Objective

Polygenic risk scores (PRS) allow risk stratification using common single‐nucleotide polymorphisms (SNPs), and clinical applications are currently explored for several diseases. This study was undertaken to assess the risk of hip and knee osteoarthritis (OA) using PRS.

Methods

We analyzed 12,732 individuals from a population‐based cohort from the Rotterdam Study (n = 11,496), a clinical cohort (Cohort Hip and Cohort Knee [CHECK] study; n = 908), and a high‐risk cohort of overweight women (Prevention of Knee OA in Overweight Females [PROOF] study; n = 328), for the association of the PRS with prevalence/incidence of radiographic OA, of clinical OA, and of total hip replacement (THR) or total knee replacement (TKR). The hip PRS and knee PRS contained 44 and 24 independent SNPs, respectively, and were derived from a recent genome‐wide association study meta‐analysis. Standardized PRS (with Z transformation) were used in all analyses.

Results

We found a stronger association of the PRS for clinically defined OA compared to radiographic OA phenotypes, and we observed the highest PRS risk stratification for TKR/THR. The odds ratio (OR) per SD was 1.3 for incident THR (95% confidence interval [95% CI] 1.1–1.5) and 1.6 (95% CI 1.3–1.9) for incident TKR in the Rotterdam Study. The knee PRS was associated with incident clinical knee OA in the CHECK study (OR 1.3 [95% CI 1.1–1.5]), but not for the PROOF study (OR 1.2 [95% CI 0.8–1.7]). The OR for OA increased gradually across the PRS distribution, up to 2.1 (95% CI 1.4–3.2) for individuals with the 10% highest PRS compared to the middle 50% of the PRS distribution.

Conclusion

Our findings validated the association of PRS across OA definitions. Since OA is becoming frequent and primary prevention is not commonly applicable, PRS‐based risk assessment could play a role in OA prevention. However, the utility of PRS is dependent on the setting. Further studies are needed to test the integration of genetic risk assessment in diverse health care settings.

Dual functions of microRNA-17 in maintaining cartilage homeostasis and protection against osteoarthritis

Damaged hyaline cartilage has no capacity for self-healing, making osteoarthritis (OA) "difficult-to-treat". Cartilage destruction is central to OA patho-etiology and is mediated by matrix degrading enzymes. Here we report decreased expression of miR-17 in osteoarthritic chondrocytes and its deficiency contributes to OA progression. Supplementation of exogenous miR-17 or its endogenous induction by growth differentiation factor 5, effectively prevented OA by simultaneously targeting pathological catabolic factors including matrix metallopeptidase-3/13 (MMP3/13), aggrecanase-2 (ADAMTS5), and nitric oxide synthase-2 (NOS2). Single-cell RNA sequencing of hyaline cartilage revealed two distinct superficial chondrocyte populations (C1/C2). C1 expressed physiological catabolic factors including MMP2, and C2 carries synovial features, together with C3 in the middle zone. MiR-17 is highly expressed in both superficial and middle chondrocytes under physiological conditions, and maintains the physiological catabolic and anabolic balance potentially by restricting HIF-1α signaling. Together, this study identified dual functions of miR-17 in maintaining cartilage homeostasis and prevention of OA.

Effectiveness and cost-effectiveness of a combined lifestyle intervention compared with usual care for patients with early-stage knee osteoarthritis who are overweight (LITE): protocol for a randomised controlled trial

INTRODUCTION

Obesity is the most important modifiable risk factor for knee osteoarthritis (KOA). Especially in an early stage of the disease, weight loss is important to prevent further clinical and structural progression. Since 2019, general practitioners (GPs) in the Netherlands can refer eligible patients to a combined lifestyle intervention (GLI) to promote physical activity, healthy nutrition and behavioural change. However, GPs scarcely refer patients with KOA to the GLI potentially due to a lack of evidence about the (cost-)effectiveness. The aim of this study is to determine the (cost-)effectiveness of the GLI for patients with early-stage KOA in primary care.

METHODS AND ANALYSIS

For this pragmatic, multi-centre randomised controlled trial, 234 participants (aged 45-70 years) with National Institute for Health and Care Excellence (NICE) guideline diagnosis of clinical KOA and a body mass index above 25 kg/m² will be recruited using a range of online and offline strategies and from general practices in the Netherlands. Participants will receive nine 3-monthly questionnaires. In addition, participants will be invited for a physical examination, MRI assessment and blood collection at baseline and at 24-month follow-up. After the baseline assessment, participants are randomised to receive either the 24-month GLI programme in addition to usual care or usual care only. Primary outcomes are self-reported knee pain over 24 months, structural progression on MRI at 24 months, weight loss at 24 months, as well as societal costs and Quality-Adjusted Life-Years over 24-month follow-up. Analyses will be performed following the intention-to-treat principle using linear mixed-effects regression models.

ETHICS AND DISSEMINATION

Ethical approval was obtained through the Medical Ethical Committee of the Erasmus MC University Medical Center Rotterdam, The Netherlands (MEC-2020-0943). All participants will provide written informed consent. The results will be disseminated through publications in peer-reviewed journals, presentations at international conferences and among study participants and healthcare professionals.

TRIAL REGISTRATION NUMBER

Netherlands Trial Registry (NL9355).

Self-Management for Knee Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Knee osteoarthritis (KOA) is a high incidence chronic joint disease that seriously affects patients' quality of life, and current treatment methods have limited efficacy. Self-management may be an effective strategy for KOA, and clinicians have been showing increased interest recently. However, the effectiveness of self-management for KOA remains controversial.

Purpose

This study aims to systematically evaluate the effectiveness of self-management for KOA.

Methods

We screened articles published in MEDLINE, Cochrane Library, EMBASE, and Web of Science until September 17, 2021. The main outcomes included pain, knee function, stiffness, WOMAC (total), physical function, arthritis self-efficacy (ASE-pain), arthritis self-efficacy (ASE-other symptoms), mental health, and quality of life.

Results

Thirteen randomized controlled trials (RCTs) were finally included (n = 1610). Meta-analysis showed differences in pain, knee function, stiffness, ASE-pain, ASE-other symptoms, mental health, and quality of life between the self-management and control groups. Of the nine outcomes evaluated, four were highly heterogeneous, and the quality of evidence ranged from very low to moderate.

Conclusion

The meta-analysis results showed that self-management might help improve the pain, knee function, stiffness, ASE, mental health, and quality of life in patients with KOA. However, it has no significant effect on WOMAC (total) and physical function. Considering that this study has some limitations, we cannot draw clear conclusions based on the results of this study. Nevertheless, we offer much needed insight and encourage more rigorously designed and implemented RCTs in the future to substantiate our conclusions.

Elective lower limb orthopedic arthroplasty surgery in patients with pulmonary hypertension

Patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (PH) are at increased risk when undergoing anesthesia and major surgery. Data on outcomes for elective orthopedic surgery in patients with PH are limited. A patient pathway was established to provide access to elective lower limb arthroplasty. This included assessment of orthopedic needs, fitness for anesthesia, preoperative optimization, and intra- and postoperative management. Patient data were retrospectively retrieved using patient's hospital records. Between 2012 and 2020, 29 operations (21 total hip replacements [THRs], 7 total knee replacements [TKRs], 1 total hip revision) were performed in 25 patients (mean age: 67 years). Perioperatively, 72% were treated with low-dose intravenous prostanoid. All had arterial lines, and central access and perioperative lithium dilution cardiac output monitoring was used in 86% of cases. Four patients underwent GA, 21 spinal anesthesia, and 4 CSE anesthesia. Supplemental nerve blocks were performed in all patients undergoing general, and 12 of 21 undergoing spinal anesthesia. All were managed in high dependency postoperatively. Hospital length of stay and complication rates were higher than reported in non-PH patients. Perioperative complications included hypotension requiring vasopressors (n = 10), blood transfusion (n = 7), nonorthopedic infection (n = 4), and decompensated right heart failure (n = 1). There was no associated mortality. All implants were functioning well at 6 weeks and subsequent follow-up. EmPHasis-10 quality of score decreased by 5.5 (±2.1) (p = 0.04). A dedicated multiprofessional pathway can be used to safely select and manage patients with PH through elective lower limb arthroplasty.

Structural and Functional Abnormalities in Knee Osteoarthritis Pain Revealed With Multimodal Magnetic Resonance Imaging

The knee osteoarthritis (KOA) pain is the most common form of arthritis pain affecting millions of people worldwide. Long-term KOA pain causes motor impairment and affects affective and cognitive functions. However, little is known about the structural and functional abnormalities induced by long-term KOA pain. In this work, high-resolution structural magnetic resonance imaging (sMRI) and resting-state functional MRI (rs-fMRI) data were acquired in patients with KOA and age-, sex-matched healthy controls (HC). Gray matter volume (GMV) and fractional amplitude of low-frequency fluctuation (fALFF) were used to study the structural and functional abnormalities in patients with KOA. Compared with HC, patients with KOA showed reduced GMV in bilateral insula and bilateral hippocampus, and reduced fALFF in left cerebellum, precentral gyrus, and the right superior occipital gyrus. Patients with KOA also showed increased fALFF in left insula and bilateral hippocampus. In addition, the abnormal GMV in left insula and fALFF in left fusiform were closely correlated with the pain severity or disease duration. These results indicated that long KOA pain leads to brain structural and functional impairments in motor, visual, cognitive, and affective functions that related to brain areas. Our findings may facilitate to understand the neural basis of KOA pain and the future therapy to relieve disease symptoms.

One-stage bilateral unicompartmental knee arthroplasty is a suitable option vs. the two-stage approach: a meta-analysis

To compare one-stage vs. two-stage bilateral unicondylar knee arthroplasty (UKA) in terms of complications, mortality, reinterventions, transfusion rate, days to discharge, and outcomes for the treatment of bilateral mono-compartmental knee osteoarthritis.

A systematic review was performed in the PubMed, Web of Science, and Cochrane databases up to February 2021. Randomized controlled trials, case-control studies, and case series describing the use of bilateral UKA were retrieved. A meta-analysis was performed on complications, mortality, reinterventions, transfusion rate, and days to discharge comparing one-stage vs. two-stage replacement, and outcomes were also reported. Assessment of risk of bias and quality of evidence was performed with the Newcastle-Ottawa Scale.

Fifteen articles were included on 1451 patients who underwent bilateral UKA (44.9% men, 55.1% women, mean age 66 years). The systematic review documented, for bilateral one-stage UKA: 2.6% major and 5.4% minor complication rates, 0.5% mortality, 1.9% reintervention, 4.1% transfusion rates, and 4.5 mean days to discharge. No studies reported functional differences. The meta-analysis did not find differences for major complications, minor complications, mortality, reintervention, transfusion rates, or days to discharge versus two-stage bilateral procedures. The operative time was 112.3 vs. 125.4 minutes for one-stage and two-stage surgeries, respectively. The overall quality of the retrieved studies was high.

Bilateral single-stage UKA is a safe procedure, with a few complications, and overall positive clinical results. No differences were found in terms of complications, mortality, reinterventions, transfusion rate, and days to discharge in comparison with the two-stage approach.

Cite this article: EFORT Open Rev 2021;6:1063-1072. DOI: 10.1302/2058-5241.6.210047

Cost-effectiveness of an 8-week supervised education and exercise therapy programme for knee and hip osteoarthritis: a pre-post analysis of 16 255 patients participating in Good Life with osteoArthritis in Denmark (GLA:D)

OBJECTIVES

To evaluate 1-year cost-effectiveness of an 8-week supervised education and exercise programme delivered in primary care to patients with symptomatic knee or hip osteoarthritis (OA).

DESIGN

A registry-based pre-post study linking patient-level data from the Good Life with osteoArthritis in Denmark (GLA:D) registry to national registries in Denmark.

SETTING AND PARTICIPANTS

16 255 patients with symptomatic knee or hip OA attending GLA:D.

INTERVENTION

GLA:D is a structured supervised patient education and exercise programme delivered by certified physiotherapists and implemented in Denmark.

OUTCOME MEASURES

Adjusted healthcare costs per Quality-Adjusted Life Year (QALY) gained from baseline to 1 year (ratio of change in healthcare costs to change in EuroQoL 5-Dimensions 5-Level questionnaire (EQ-5D)). All adjusted measures were estimated using a generalised estimating equation gamma regression model for repeated measures. Missing data on EQ-5D were imputed with Multiple Imputations (3 months: 23%; 1 year: 39 %).

RESULTS

Adjusted change in healthcare cost was 298€ (95% CI: 206 to 419) and 640€ (95% CI: 400 to 1009) and change in EQ-5D was 0.035 (95% CI: 0.033 to 0.037) and 0.028 (95% CI: 0.025 to 0.032) for knee and hip patients, respectively. Hence estimated adjusted healthcare costs per QALY gained was 8497€ (95% CI: 6242 to 11 324) for knee and 22 568€ (95% CI: 16 000 to 31 531) for hip patients. In patients with high compliance, the adjusted healthcare costs per QALY gained was 5438€ (95% CI: 2758 to 9231) for knee and 17 330€ (95% CI: 10 041 to 29 364) for hip patients. Healthcare costs per QALY were below conventional thresholds for willingness-to-pay at 22 804€ (20 000£) and 43 979€ (US$50 000), except the upper limit of the 95% CI for hip patients which was in between the two thresholds.

CONCLUSIONS

A structured 8-week supervised education and exercise programme delivered in primary care was cost-effective at 1 year in patients with knee or hip OA supporting large-scale implementation in clinical practice.

Return to work and productivity loss after surgery: A health economic evaluation

BACKGROUND

We aimed to identify preoperative psychosocial factors associated with return-to-work (RTW) and the associated cost of productivity loss due to work absenteeism following surgery. Research demonstrates a high economic burden from productivity loss after surgery, but the comparative cost of productivity loss relative to income across different operations has not been examined.

MATERIALS AND METHODS

A mixed surgical cohort recruited for a randomized controlled trial were prospectively followed for up to two years following surgery with daily phone assessments to three months, weekly assessments thereafter to six months, then monthly assessments thereafter to determine RTW status, opioid use and pain.

RESULTS

183 of 207 (88.3%) patients in paid employment prior to surgery, who provided at least one day of follow-up, were included in this analysis. The average cost of productivity loss due to work absenteeism was $13 761 (median $9064). Patients who underwent total knee replacement incurred the highest income loss. Medical claims filed before surgery were significantly associated with relative income loss (AOR 5.09; 95% CI 1.73-14.96; p < 0.01) and delayed postoperative RTW. Elevated preoperative PTSD symptoms were associated with delayed RTW (HR 0.78; 95%CI 0.63-0.96; p-value = 0.02) while male gender (HR 1.63; 95%CI 1.11-2.38; p-value = 0.01) was associated with faster postoperative RTW.

CONCLUSION

Surgery places a high economic burden on individuals due to postoperative productivity loss. Multidisciplinary approaches, such as pathways, that facilitate the operation and recovery may mitigate the economic consequences for patients, employers, and the healthcare system.

An individualized decision aid for physicians and patients for total knee replacement in osteoarthritis (Value-based TKR study): study protocol for a multi-center, stepped wedge, cluster randomized controlled trial

Background

Total knee replacement (TKR) is one of the most commonly performed routine procedures in the world. Prognostic studies indicate that the number of TKR will further increase constituting growing burden on healthcare systems. There is also substantial regional heterogeneity in TKR rates within and between countries. Despite the known therapeutic effects, a subset of patients undergoing TKR does not benefit from the procedure as intended. To improve the appropriateness of TKR indication, the EKIT initiative (“evidence and consensus based indication critera for total arthroplasty”) developed a clinical guideline for Germany on the indication of TKR. This guideline is the basis for a digital medical decision aid (EKIT tool) to facilitate shared decision making (SDM) in order to improve decision quality for elective surgery. The aim of this cluster randomized trial is to investigate the effectiveness of the EKIT tool on decision quality.

Methods

The Value-based TKR study is a prospective pragmatic multi-center, stepped wedge, cluster randomized controlled trial (SW-RCT). The EKIT tool provides (1) a systematic presentation of individual patient and disease-specific information (symptoms, expectations), (2) the fulfillment of the indication criteria and (3) health information about safety and effectiveness of TKR. All study sites will follow routine care as control clusters until the start of the intervention. In total, there will be 10 clusters (study sites) and 6 sequential steps over 16 month, with clusters receiving the intervention with a minimum 2 months of standard routine care. The primary outcome is patients’ decision quality measured with the Decision Quality Instrument (DQI)-Knee Osteoarthritis questionnaire. Furthermore, we will collect information on global patient satisfaction, patient reported outcome measures and the fulfilment of the individual expectations 12 months after SDM. The power calculation yielded an estimated power of 89% using robust Poisson regression under the following assumptions: 10 study sites with a total of N=1,080 patients (including a dropout rate of 11%), a 10% increase in decision quality due to the use of the EKIT tool, and a significance level of 5%.

Discussion

There is a high potential for transferring the intervention into routine practice if the evaluation is positive.

Trial registration

ClinicalTrials.gov: NCT04837053. Registered on 08/04/2021.

Factors Associated with Knee Arthroplasty in a Knee Osteoarthritis Patient Cohort Treated with Intra-articular Injections of Hylan G-F 20

Hylan G-F 20 viscosupplementation can be used to treat knee osteoarthritis pain. This study evaluated time to knee arthroplasty (KA), KA risk factors, and health care resource utilization in patients aged ≥18 years with claims in the Optum Clinformatics Data Mart database (2006-2016) for knee osteoarthritis treated with at least one course of hylan G-F 20. Kaplan-Meier analysis estimated KA risk from osteoarthritis diagnosis and first hylan G-F 20 treatment. KA risk factors were determined using multivariate Cox regression. Among 62,033 patients treated with hylan G-F 20 and/or hylan G-F 20 single intra-articular injection, 60 to 64% did not undergo KA 8 years following first injection. KA risk factors from time of osteoarthritis diagnosis and first hylan G-F 20 treatment were similar: increased age, fewer comorbidities, fewer hylan G-F 20 treatments, female sex, and no ultrasound/fluoroscopy for injection guidance. Patients who underwent KA versus those who did not had more office visits and claims for opioids, nonsteroidal anti-inflammatory drugs, and physical therapy. Patients less likely to undergo KA were younger (<40 years), had more comorbidities, received more courses of hylan G-F 20, were males, or received ultrasound/fluoroscopic injection guidance. Patients who did not receive KA versus those who did used fewer health care resources.

Cost, safety, and rehabilitation of same-stage, bilateral total knee replacements compared to two-stage total knee replacements

Background

Many patients experience bilateral knee osteoarthritis and require bilateral total knee replacement (TKR). Same-stage, bilateral TKR is proposed to be a cost-effective and safe solution compared to two-stage, but conflicting results in the literature are reported. We aim to compare the costs, safety, and rehabilitation performance of patients in same-stage versus two-stage, bilateral TKR with our centre’s perioperative protocol.

Materials and methods

We retrospectively reviewed 175 patients (95 same-stage, 80 two-stage) who had undergone bilateral TKR in our centre. Patient selection for same-stage, bilateral TKR was strictly protocol-driven and required fulfilment of all criteria, including age < 75 years, American Society of Anesthesiologists (ASA) grade 1 or 2, body mass index (BMI) < 40, and having non-complex arthritis. All patients followed a standardised pre-operative, intra-operative, and post-operative Enhanced Recovery After Surgery (ERAS) protocol. The cost, safety profiles, and rehabilitation outcomes were compared between the same-stage and two-stage groups.

Results

The same-stage, bilateral TKR reduced the length of hospital stays by 5.71 days per patient, decreased the operation time by 27.4 min, saved 3.34 (18.6%) physiotherapy sessions, and 3.78 (51.5%) occupational therapy sessions. The same-stage group experienced a higher haemoglobin drop but no significant difference in transfusion percentage, transfusion volume, complication rate, and readmission rate. The two-stage subgroup with anaesthetic risk, age, and BMI similar to the same-stage group showed the same results. Same-stage, bilateral TKR patients experienced no significant difference in final post-operative pain levels and rehabilitation outcomes as two-stage TKR patients.

Conclusion

This study showed that same-stage, bilateral TKR can reduce costs, with similar safety profiles and rehabilitation outcomes compared to the two-stage, bilateral TKR.

Total Hip and Knee Arthroplasties Are Highly Cost-Effective Procedures: The Importance of Duration of Follow-Up

BACKGROUND

Total hip and knee arthroplasties (THA/TKA) are clinically effective but high cost procedures. The aim of this study is to perform a cost-effectiveness analysis of THA and TKA in the New Zealand (NZ) healthcare system.

METHODS

Data were collected from 713 patients undergoing THA and 520 patients undergoing TKA at our local public hospital. SF-6D utility values were obtained from participants preoperatively and 1-year postoperatively, and deaths and any revision surgeries from patient records and the New Zealand Joint Registry at minimum 8-year follow-up. A continuous-time state-transition simulation model was used to estimate costs and health gains to 15 years. Quality-adjusted life years (QALYs), treatment costs, and incremental cost-effectiveness ratios (ICERs) were calculated to determine cost effectiveness. ICERs below NZ gross domestic product (GDP; NZ$60 600) and 0.5 times GDP per capita were considered "cost effective" and "highly cost effective" respectively.

RESULTS

Cumulative health gains were 2.8 QALYs (THA) and 2.3 QALYs (TKA) over 15 years. Cost effectiveness improved from ICERs of NZ$74,400 (THA) and NZ$93,000 (TKA) at 1 year to NZ$6000 (THA) and NZ$7500 (TKA) at 15 years. THA and TKA were cost effective after 2 years and highly cost effective after 3 years. QALY gains and cost effectiveness were greater in patients with worse preoperative functional status and younger age.

CONCLUSION

THA and TKA are highly cost-effective procedures over longer term horizons. Although preoperative status and age were associated with cost effectiveness, both THA and TKA remained cost effective in patients with less severe preoperative scores and older ages.

Aseptic Revision Total Knee Can Be Performed as Part of a Short-Stay Arthroplasty Program: An Analysis of the National Surgical Quality Improvement Program Database

Total knee arthroplasty (TKA) is becoming an increasingly common procedure to alleviate knee pain often associated with osteoarthritis. As the number of revision TKAs performed continues to increase, there remains a debate regarding the efficacy of discharging patients earlier than the conventional 3 to 4 days in the postoperative period. A variety of studies have begun to show that interchangably discharge in the primary TKA setting has an economical benefit while causing either a reduction or no difference in patient outcomes. This study aims to determine the effect of rapid discharge at 0- to 2-day postoperative stay compared to the conventional 3- to 4-day postoperative stay on postdischarge complications in patients undergoing revision TKA. A retrospective cohort study was conducted using data collected through the American College of Surgeons National Quality Improvement Program Database. All patients who underwent aseptic revision TKA between 2005 and 2016 were identified and stratified into groups based on length of stay: 0 to 2 days versus 3 to 4 days. Patients suffering from predischarge complications were excluded to minimize bias. Single-component versus both-component revisions were analyzed. The incidence of adverse events following discharge was evaluated with univariate and logistic multivariate analyses where appropriate. Patients who underwent single-component revisions and were discharged rapidly were less likely to develop minor complications (p = 0.001; odds ratio [OR]: 0.355; 95% confidence interval [CI]: 0.188-0.671) and septic complications (p = 0.016; OR: 0.011; 95% CI: 0-0.430) within the 30-day postoperative period. No differences were observed in discharge cohorts among patients undergoing both-component revisions. We found that rapid discharge following aseptic revision TKA is not associated with increased risks for postoperative complications. Rapid discharge may have benefits for healthy patients undergoing single-component revisions. Careful selection of revision TKA patients for rapid discharge may help to lower the increasing costs of the procedure and improve patient outcomes. Further study is required to refine the selection criteria to identify patients eligible for short stay or outpatient revision TKA.

Estimation of Expenditure and Challenges Related to Rehabilitation After Knee Arthroplasty: A Hospital-Based Cross-Sectional Study

BACKGROUND

Expenditure for rehabilitation following knee arthroplasty for osteoarthritis- and rehabilitation-related challenges following discharge to home after surgery is not available in the Indian context.

OBJECTIVES

To estimate cost of rehabilitation and document challenges in following rehabilitation advices, from a patient perspective.

METHODS

We conducted a hospital-based cross-sectional study of patients visiting the orthopedic department at a tertiary care public-funded hospital in New Delhi and included those who recently (less than 4 months) underwent primary knee arthroplasty for osteoarthritis. A trained physiotherapist not involved in clinical care collected information on expenditures incurred after discharge from hospital, patient's ability to recall the advices given by the physician and challenges they experienced using a semi-structured questionnaire. We report median costs by category of direct and indirect cost and used linear regression to explore determinants of cost.

RESULTS

We interviewed 82 consecutive patients (mean age 60.8 years and 68% females) with median time since surgery of 28 days. More than half (52%) sought some support for physiotherapy. The median cost of rehabilitation was INR 18,395 (Interquartile-range 11,325-27,775). Direct medical cost contributed to 74% of total cost (32% fee for services, 21% medications and lab investigations, 21% assistive devices). Twenty percent higher costs were incurred among those undergoing bilateral knee surgery after adjusting for age, sex, income, and type of physiotherapy support sought. Challenges were related to recall of advices, not understanding the recovery process and pain management.

CONCLUSION

About half patients undergoing knee arthroplasty seek support for rehabilitation after discharge to home contributing to a major portion of expenses incurred during rehabilitation. Cost-effective support mechanism for home-based rehabilitation is required for improving patient rehabilitation experiences.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00405-6.

Serious adverse events and 30-day hospital readmission rate following elective total knee arthroplasty: a systematic review and meta-analysis

BACKGROUND

Elective total knee arthroplasty (TKA) is a common surgery which has evolved rapidly. However, there are no recent large systematic reviews of serious adverse event (SAE) rate and 30-day readmission rate (30-dRR) or an indication of whether surgical methods have improved.

METHODS

To obtain a pooled estimate of SAE rate and 30-dRR following TKA, we searched Medline, Web of Science, Cochrane Library, and Google Scholar databases. Data were extracted by two authors following PRISMA guidelines. Eligibility criteria were defined prior to a comprehensive search. Studies were eligible if they were published in 2007 or later, described sequelae of TKA with patient N > 1000, and the SAE or 30-dRR rate could be calculated. SAEs included return to operating room, death or coma, venous thromboembolism (VTE), deep infection or sepsis, myocardial infarction, heart failure or cardiac arrest, stroke or cerebrovascular accident, or pneumonia.

RESULTS

Of 248 references reviewed, 28 are included, involving 10,153,503 patients; this includes 9,483,387 patients with primary TKA (pTKA), and 670,116 patients with revision TKA (rTKA). For pTKA, the SAE rate was 5.7% (95% CI 4.4-7.2%, I2 = 100%), and the 30-dRR was 4.8% (95% CI 4.3-5.4%, I2 = 100%). For rTKA, the SAE rate was 8.5% (95% CI 8.3-8.7%, I2 = 77%), while the 30-dRR was 7.2% (95% CI 6.4-8.0%, I2 = 81%). Odds of 30-dRR following pTKA were about half that of rTKA (OR 0.57, 95% CI 0.53-0.62%, p < 0.001, I2 = 45%). Of patients who received pTKA, the commonest SAEs were VTE (1.22%; 95% CI 0.83-1.70%) and genitourinary complications including renal insufficiency or renal failure (1.22%; 95% CI 0.83-1.67%). There has been significant improvement in SAE rate and 30-dRR since 2010 (χ2 test < 0.001).

CONCLUSIONS

TKA procedures have a relatively low complication rate, and there has been a significant improvement in SAE rate and 30-dRR over the past decade.

Trends in Articular Cartilage Tissue Engineering: 3D Mesenchymal Stem Cell Sheets as Candidates for Engineered Hyaline-Like Cartilage

Articular cartilage defects represent an inciting factor for future osteoarthritis (OA) and degenerative joint disease progression. Despite multiple clinically available therapies that succeed in providing short term pain reduction and restoration of limited mobility, current treatments do not reliably regenerate native hyaline cartilage or halt cartilage degeneration at these defect sites. Novel therapeutics aimed at addressing limitations of current clinical cartilage regeneration therapies increasingly focus on allogeneic cells, specifically mesenchymal stem cells (MSCs), as potent, banked, and available cell sources that express chondrogenic lineage commitment capabilities. Innovative tissue engineering approaches employing allogeneic MSCs aim to develop three-dimensional (3D), chondrogenically differentiated constructs for direct and immediate replacement of hyaline cartilage, improve local site tissue integration, and optimize treatment outcomes. Among emerging tissue engineering technologies, advancements in cell sheet tissue engineering offer promising capabilities for achieving both in vitro hyaline-like differentiation and effective transplantation, based on controlled 3D cellular interactions and retained cellular adhesion molecules. This review focuses on 3D MSC-based tissue engineering approaches for fabricating “ready-to-use” hyaline-like cartilage constructs for future rapid in vivo regenerative cartilage therapies. We highlight current approaches and future directions regarding development of MSC-derived cartilage therapies, emphasizing cell sheet tissue engineering, with specific focus on regulating 3D cellular interactions for controlled chondrogenic differentiation and post-differentiation transplantation capabilities.

The cost-effectiveness of computer navigation in primary total knee replacement: a scoping review

Despite additional costs associated with the use of computer navigation technology in total knee replacement (TKR), its impact on quality-adjusted life years following surgery has not been demonstrated. Cost-effectiveness evaluations require a balanced assessment of both quality and cost metrics.

This review sought to evaluate the cost-effectiveness of computer navigation, identify barriers to translation, and suggest directions for further investigation. A systematic search of the Cost-Effectiveness Analysis Registry, PubMed, and Embase was undertaken.

Cost-effectiveness analyses of computer navigation in primary total knee replacement were identified. Only primary studies of cost-effectiveness analyses published in the English language from the year 2000 onwards were included. Studies that reported secondary data were excluded from the analysis. Four publications met the inclusion criteria.

Estimated gains in quality-adjusted life years attributed to reductions in revision surgery were 0.0148 to 0.0164 over 10 years, and 0.0192 (95% CI –0.002 to 0.0473) over 15 years. Cost estimates ranged from 952 kr (US $90, 2020) per case at 250 TKRs/year, to $1,920 US per case at 25 TKRs/year.

The estimated probability of meeting local cost-effectiveness thresholds was 54% in the United States and 92% in the United Kingdom. These data were not available for Norway.

The cost-effectiveness of computer navigation in current practice settings remains uncertain, with the use of this technology associated with marginal increased quality-adjusted life years (QALYs) at additional cost. Existing analyses demonstrated a number of limitations which restrict the potential for translation to practice and policy settings. Further research evaluating the impact of computer navigation on QALYs following primary TKR is required to inform contemporary cost-effectiveness evaluations.

Cite this article: EFORT Open Rev 2021;6:173-180. DOI: 10.1302/2058-5241.6.200073

Excavating bioactivities of nanozyme to remodel microenvironment for protecting chondrocytes and delaying osteoarthritis

Osteoarthritis (OA) is the main cause of disability in the elderly. Effective intervention in the early and middle stage of osteoarthritis can greatly prevent or slow down the development of the disease, and reduce the probability of joint replacement. However, there is to date no effective intervention for early and middle-stage OA. OA microenvironment mainly destroys the balance of oxidative stress, extracellular matrix synthesis and degradation of chondrocytes under the joint action of biological and mechanical factors. Herein, hollow Prussian blue nanozymes (HPBzymes) were designed via a modified hydrothermal template-free method. The aim of this study was to investigate the effects of HPBzymes on chondrocytes and the progression of OA. The intrinsic bioactivities of HPBzymes were excavated in vitro and in vivo, remodeling microenvironment for significantly protecting chondrocytes and delaying the progression of traumatic OA by inhibiting reactive oxygen species (ROS) and Rac1/nuclear factor kappa-B (NF-κB) signaling in a rat model. HPBzyme significantly diminished interleukin (IL)-1β-stimulated inflammation, extracellular matrix degradation, and apoptosis of human chondrocytes. HPBzyme attenuated the expression of Rac1 and the ROS levels and prevented the release and nuclear translocation of NF-κB. Deeply digging the intrinsic bioactivities of nanozyme with single component to remodel microenvironment is an effective strategy for ROS-associated chronic diseases. This study reveals that excavating the bioactivities of nanomedicine deserves attention for diagnosis and treatment of severe diseases.

The influence of previous arthroscopic treatment on subsequent primary total knee arthroplasty: the comparison between bilateral knees of the same patient

BACKGROUND

To explore whether previous arthroscopic knee surgery affects future total knee arthroplasty (TKA) results or not.

METHODS

A total of 56 patients with the previous arthroscopic treatment on one knee underwent subsequent bilateral total knee arthroplasty in our hospital from September 2012 to July 2018. Data on each patient were collected in regards to changes in postoperative clinical and functional scores, various other scores, as well as postoperative functional recovery and complications. We defined the knees with a previous arthroscopic history as group A, and the counter side as group B. The Knee Society clinical score, functional scores, range of motion (ROM), finger joint size (FJS), visual analogue scale (VAS) scores were assessed before and after surgery. Using the Kolmogorov-Smirnov Test to test the normality of continuous variables, and the chi-square test to compare the rate of reoperation and complications between two groups. For all statistical comparisons, P < 0.05 was considered significant.

RESULTS

There were no statistically significance differences found in postoperative Knee Society clinical scores and functional scores between group A and group B, as well as in ROM, FJS, VAS scores and local complications.

CONCLUSION

There were no statistically significant differences found in postoperative functional recovery and complications in patients, who underwent total knee arthroplasty with previous knee arthroscopy.

Efficacy of Intensive Acupuncture Versus Sham Acupuncture in Knee Osteoarthritis: A Randomized Controlled Trial

OBJECTIVE

To assess the efficacy of intensive acupuncture (3 times weekly for 8 weeks) versus sham acupuncture for knee osteoarthritis (OA).

METHODS

In this multicenter, randomized, sham-controlled trial, patients with knee OA were randomly assigned to receive electroacupuncture (EA), manual acupuncture (MA), or sham acupuncture (SA) 3 times weekly for 8 weeks. Participants, outcome assessors, and statisticians were blinded with regard to treatment group assignment. The primary outcome measure was response rate, which is the proportion of participants who simultaneously achieved minimal clinically important improvement in pain and function by week 8. The primary analysis was conducted using a Z test for proportions in the modified intent-to-treat population, which included all randomized participants who had ≥1 post-baseline measurement.

RESULTS

Of the 480 participants recruited in the trial, 442 were evaluated for efficacy. The response rates at week 8 were 60.3% (91 of 151), 58.6% (85 of 145), and 47.3% (69 of 146) in the EA, MA, and SA groups, respectively. The between-group differences were 13.0% (97.5% confidence interval [97.5% CI] 0.2%, 25.9%; P = 0.0234) for EA versus SA and 11.3% (97.5% CI -1.6%, 24.4%; P = 0.0507) for MA versus SA. The response rates in the EA and MA groups were both significantly higher than those in the SA group at weeks 16 and 26.

CONCLUSION

Among patients with knee OA, intensive EA resulted in less pain and better function at week 8, compared with SA, and these effects persisted though week 26. Intensive MA had no benefit for knee OA at week 8, although it showed benefits during follow-up.

Semixup: In- and Out-of-Manifold Regularization for Deep Semi-Supervised Knee Osteoarthritis Severity Grading From Plain Radiographs

Knee osteoarthritis (OA) is one of the highest disability factors in the world. This musculoskeletal disorder is assessed from clinical symptoms, and typically confirmed via radiographic assessment. This visual assessment done by a radiologist requires experience, and suffers from moderate to high inter-observer variability. The recent literature has shown that deep learning methods can reliably perform the OA severity assessment according to the gold standard Kellgren-Lawrence (KL) grading system. However, these methods require large amounts of labeled data, which are costly to obtain. In this study, we propose the Semixup algorithm, a semi-supervised learning (SSL) approach to leverage unlabeled data. Semixup relies on consistency regularization using in- and out-of-manifold samples, together with interpolated consistency. On an independent test set, our method significantly outperformed other state-of-the-art SSL methods in most cases. Finally, when compared to a well-tuned fully supervised baseline that yielded a balanced accuracy (BA) of 70.9 ± 0.8% on the test set, Semixup had comparable performance - BA of 71 ± 0.8% ( p=0.368 ) while requiring 6 times less labeled data. These results show that our proposed SSL method allows building fully automatic OA severity assessment tools with datasets that are available outside research settings.

The STAK tool: evaluation of a new device to treat arthrofibrosis and poor range of movement following total knee arthroplasty and major knee surgery

Aims

This study aims to evaluate a new home medical stretching device called the Self Treatment Assisted Knee (STAK) tool to treat knee arthrofibrosis.

Methods

35 patients post-major knee surgery with arthrofibrosis and mean range of movement (ROM) of 68° were recruited. Both the STAK intervention and control group received standard physiotherapy for eight weeks, with the intervention group additionally using the STAK at home. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Oxford Knee Scores (OKS) were collected at all timepoints. An acceptability and home exercise questionnaire capturing adherence was recorded after each of the interventions.

Results

Compared to the control group, the STAK intervention group made significant gains in mean ROM (30° versus 8°, p < 0.0005), WOMAC (19 points versus 3, p < 0.0005), and OKS (8 points versus 3, p < 0.0005). The improvements in the STAK group were maintained at long-term follow-up. No patients suffered any complications relating to the STAK, and 96% of patients found the STAK tool ‘perfectly acceptable’.

Conclusion

The STAK tool is effective in increasing ROM and reducing pain and stiffness. Patients find it acceptable and adherence to treatment was high. This study indicates that the STAK tool would be of benefit in clinical practice and may offer a new, cost-effective treatment for arthrofibrosis.

Cite this article: Bone Joint Open 2020;1-8:465–473.