Establishing outcome measures in early knee osteoarthritis

Degeneration of the cartilage quality is correlated with a higher intramuscular fat infiltration of the vastus medialis in older adults with pre-to-mild knee osteoarthritis

PURPOSE

To quantitatively verify whether degeneration in the quality of the medial femoral cartilage is correlated with muscle volume loss and intramuscular adipose tissue (IntraMAT) infiltration in quadriceps using magnetic resonance imaging (MRI).

METHODS

Of the 66 older adult participants ≥60 years old (74.5 ± 6.9 years), 29 were female. All participants were patients with pre-to-mild knee osteoarthritis. Muscle volume and IntraMAT infiltration of the four individual muscles, the rectus femoris (RF), vastus medialis (VM), vastus intermedius, and vastus lateralis were assessed, using proton density-weighted and 2-point Dixon MR images. Based on the MRI T2 mapping, the T2 relaxation times of the weight-bearing surface of the medial femoral cartilage were calculated. Simple linear regression analyses were performed, evaluating the correlations between the T2 relaxation time of the medial femoral cartilage and quadriceps muscle volume and IntraMAT. Multiple linear regression analysis using a stepwise method was performed, determining which indicators of the four individual muscles correlated with cartilage quality degeneration.

RESULTS

Simple linear regression analyses revealed that a longer T2 relaxation time of the medial femoral cartilage was positively correlated with IntraMAT infiltration of the entire quadriceps muscle, RF, and VM, however not with the quadriceps muscle volume. Multiple linear regression analysis revealed that VM IntraMAT was particularly correlated with the extension of T2 relaxation time of the medial femoral cartilage.

CONCLUSIONS

In older adults with pre-to-mild knee osteoarthritis, IntraMAT infiltration of the quadriceps muscles, particularly of the VM was correlated with degeneration in the quality of the medial femoral cartilage.

Physical functions assessed by lower limb performance-based and self-reported outcome measures for knee musculoskeletal conditions: A scoping review

BACKGROUND

Physical function assessment is key for the management of knee musculoskeletal conditions. There are a wide variety of self-reported outcome measures (SROMs) and performance-based outcome measures (PBOMs) to assess physical function of individuals with knee conditions. However, the content of these measures has not been explored.

OBJECTIVE

To explore the range and frequency of physical functions assessed by lower limb PBOMs and SROMs for people with knee osteoarthritis (OA), anterior cruciate ligament (ACL) injuries, and patellofemoral pain (PFP).

METHODS

A scoping review was conducted. We included development or measurement properties studies of knee functional outcome measures for populations with knee OA, ACL injuries, and PFP. We extracted the physical functions assessed in each measure. Each identified physical function was linked to a code from the International Classification of Functioning, Disability and Health (ICF) framework.

RESULTS

4146 articles were screened. A total of 143 articles were included. The median number of physical functions assessed was nine for SROMs and one for PBOMs. The three most assessed physical functions were climbing stairs, walking short distances, and standing up from sitting. Climbing stairs was the most assessed physical function in measures for knee OA and PFP populations, whereas jumping was in measures for the ACL-injured population.

CONCLUSION

SROMs assess a broader range of physical functions, whereas PBOMs focus on discrete activities. ACL and PFP measures evaluated more challenging physical functions than knee OA measures. Current physical function outcome measures are not well suited to assess performance in knee OA populations with mild or diverse levels of impairment.

Classification Criteria For Early Knee Osteoarthritis: A Review Article

Objective The aim of this systematic review (SR) was to define the “state of the art” on classification criteria for early knee osteoarthritis (EKOA).

Methods A systematic review was performed using MEDLINE (Pubmed), Web of Science, Scopus, EMBASE, PEDro, CINAHL and Google scholar databases. Two independent reviewers conducted the eligibility review. Any type of study that proposed diagnostic criteria of EKOA was included.

Results Seven articles were included according to the inclusion criteria. The evidence presented in this SR shows that there is still no consensus regarding definition and classification of EKOA. At present, there are seven different proposals in the scientific literature, and they only agree on including knee pain and radiographic evaluation in their criteria, but they do not even consider the same situations for including these two factors.

Conclusion There is still no consensus regarding definition and classification of EKOA. Knee pain and radiological assessment seem to be the most commonly used criteria, but due to the variability encountered, it is not possible to reach a consensus on a clear definition and diagnosis of EOKA.

Early-stage vs established knee osteoarthritis: A comparative observational study on prevalence and changes in pain, function and quality of life after supervised exercise and education among 10,365 patients

OBJECTIVE

Compare prevalence and changes in outcomes among established and early-stage knee osteoarthritis (KOA) patients undertaking supervised exercise and education.

METHODS

Patients from Good Life with osteoArthritis in Denmark (GLA:D®) were stratified into three groups: established KOA (ACR/EULAR criteria), early-stage KOA (diagnostic-model-outcome ≥70%, Criteria for the Early Diagnosis of knee Osteoarthritis) or potential early-stage KOA (diagnostic-model-outcome 30-69%). Mixed-effects models and the proportion of patients by group achieving minimal clinically important improvements (MCIIs) were used to investigate changes in VAS pain intensity (0-100mm), Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL; 0-100), 40 m Walk test and 30 s chair-stand test at 3 and 12 months.

RESULTS

Compared to established KOA (61% of 10,365 patients), early-stage KOA (27%) had similar knee pain at baseline (mean (standard deviation); 51 (22) vs 45 (22)), and improvement in pain (mean (95% CI) -15 (-15 to -14) vs -14 (-15 to -13), ≥MCII: 55% vs 54%) and KOOS QoL (≥MCII: 50% vs 50%) at 12 months, and in walking speed (≥MCII: 56% vs 52%) and chair-stands (≥MCII: 55% vs 52%) at 3 months. Compared to either group, potential early-stage KOA (10%) had lower baseline pain (34 (32.7)) and less improvement in pain (-9.8 (-11.3 to -8.2; ≥MCII: 47%)), but comparable improvements in KOOS QoL (≥MCII: 50%), walking speed (≥MCII: 51%) and chair-stands (≥MCII: 51%).

CONCLUSION

Patients with early-stage KOA achieved comparable improvements at 3 and 12 months to those with established KOA, supporting supervised exercise and education as a viable management strategy for early-stage KOA.

Screening and validation of key genes associated with osteoarthritis

BACKGROUND

Osteoarthritis is recognized as a common geriatric condition characterized by irregular chronic pain. Its prevalence is steadily increasing, posing significant challenges to global public health, while some studies indicate a trend towards younger individuals being affected. This condition severely impacts patients' quality of life.

METHODS

Using the Gene Expression Omnibus (GEO) database, we downloaded datasets GSE114007, GSE169077, and GSE206848. We utilized R software to screen and confirm differentially expressed genes (DEGs) related to the development of osteoarthritis. A cross-analysis of the three datasets was conducted, with the least overlapping dataset, GSE206848, selected as the validation set. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed on the DEGs from GSE114007 and GSE169077. Weighted Gene Co-Expression Network Analysis (WGCNA) was employed to identify modules closely associated with osteoarthritis, and genes from these intersecting modules were entered into the STRING database to construct Protein-Protein Interaction Networks. The top ten genes by connectivity were identified and validated using GSE206848. Key genes were identified and preliminarily validated using Quantitative Real-Time PCR (QPCR). Subsequent validation of related genes was carried out through Western Blot (WB) analysis.

RESULTS

Differentially expressed genes were identified from the GSE114007 and GSE169077 datasets and validated in the GSE206848 dataset, with ANGPTL4 selected as the key gene. QPCR results indicated a significant difference in ANGPTL4 expression levels between normal and osteoarthritic chondrocytes. Western Blot analysis confirmed a significant difference in ANGPTL4 protein expression between normal and osteoarthritic chondrocytes.

CONCLUSION

Based on the experimental findings, ANGPTL4 appears to be a potential key gene in osteoarthritis.

Evaluating Criteria for Symptoms Suggestive of Early Osteoarthritis Over Two Years Post-Anterior Cruciate Ligament Reconstruction: Data From the New Zealand Anterior Cruciate Ligament Registry

OBJECTIVE

The objectives were to determine the prevalence of meeting criteria for symptoms suggestive of early osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) and to characterize the longitudinal changes in these symptoms during the first two years post-ACLR.

METHODS

We analyzed data from 10,231 patients aged 14 to 40 years in the New Zealand ACL Registry who completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) at 6, 12, and 24 months post-ACLR. Symptoms suggestive of early OA were defined as scoring ≤85% on at least two of four KOOS subscales. Longitudinal patterns of change were categorized as persistent, resolution, new, inconsistent, or no symptoms across the three visits. Prevalence and odds ratios (ORs) of symptoms were compared across visits, sex, and age groups using generalized estimating equations, and longitudinal patterns of symptom change were analyzed using multinomial logistic regression.

RESULTS

Prevalence of meeting criteria of symptoms suggestive of early OA was 68% at 6 months, 54% at 12 months, and 46% at 24 months post-ACLR. Longitudinally, 33% had persistent symptoms, 23% had no symptoms, 29% showed symptom resolution, 6% developed new symptoms, and 9% had inconsistent symptoms. Women consistently showed higher odds of symptoms (OR range 1.17-1.52). Older age groups demonstrated higher odds of symptoms, particularly at 6 months (OR range 1.64-2.45).

CONCLUSION

Symptoms suggestive of early OA are highly prevalent within two years post-ACLR, with one third of patients experiencing persistent symptoms. These findings indicate that symptoms are more likely to persist rather than newly develop, emphasizing the importance of early identification and targeted interventions.

Planned or recent first consultation with the general practitioner for knee complaints: Is it indicative of early-stage knee osteoarthritis?

Objective

No established definition for early-stage knee osteoarthritis (KOA) is available, nor classification criteria. Identifying the characteristics of individuals presenting with early-stage KOA symptoms can enhance diagnosis to prevent progression. This study aimed to describe clinical and structural features of individuals presenting with knee complaints within two years after their first consultation, while exploring differences in the duration of knee complaints.

Method

Baseline data was used from the LITE randomized controlled trial, assessing the effectiveness of a lifestyle intervention for individuals with knee complaints and overweight in primary care. Baseline assessments included questionnaires, clinical assessment, and MRI of the most symptomatic knee. Differences between groups with varying durations of knee complaints (<12, ≥12-<24, ≥24 months) were evaluated.

Results

Participants (N ​= ​218, 65% female, mean age 59 ​± ​6 years, mean BMI 32 ​± ​5 ​kg/m2) had a median knee complaint duration of 14 months, with an average KOOS pain score of 60 ​± ​17.46% reported their symptoms as unacceptable. Structural MRI-defined KOA was observed in 71% of participants. There were no significant differences in clinical or structural MRI features between different durations of knee complaints.

Conclusion

Within 24 months of initial consultation, over two-thirds of participants displayed MRI-defined structural KOA, and nearly half reported unacceptable symptom states. This study found no association between the duration of knee complaints and symptoms severity or structural KOA presence, underscoring the complexity of identifying stages of KOA among individuals with overweight. Future studies should explore additional features beyond current considerations to facilitate early-stage KOA diagnosis, specifically for individuals with overweight.

Persistent Early Knee Osteoarthritis Symptoms From 6 to 12 Months After Anterior Cruciate Ligament Reconstruction

CONTEXT

Early identification of knee osteoarthritis (OA) symptoms after anterior cruciate ligament reconstruction (ACLR) could enable timely interventions to improve long-term outcomes. However, little is known about the change in early OA symptoms from 6 to 12 months post-ACLR.

OBJECTIVE

To evaluate the change over time in meeting classification criteria for early knee OA symptoms from 6 to 12 months after ACLR.

DESIGN

Prospective cohort study.

SETTING

Research laboratory.

PATIENTS OR OTHER PARTICIPANTS

Eighty-two participants aged 13 to 35 years who underwent unilateral primary ACLR. On average, participants' first and second visits were 6.2 and 12.1 months post-ACLR.

MAIN OUTCOME MEASURE(S)

Early OA symptoms were classified using generic (Luyten Original) and patient population-specific (Luyten Patient Acceptable Symptom State [PASS]) thresholds on Knee injury and Osteoarthritis Outcome Score (KOOS) subscales. Changes in meeting early OA criteria were compared between an initial and follow-up visit at an average of 6 and 12 months post-ACLR, respectively.

RESULTS

Twenty-two percent of participants exhibited persistent early OA symptoms across both visits using both the Luyten Original and PASS criteria. From initial to follow-up visit, 18% to 27% had resolution of early OA symptoms, while 4% to 9% developed incident symptoms. In total, 48% to 51% had no early OA symptoms at either visit. No differences were found for change in early OA status between adults and adolescents.

CONCLUSIONS

Nearly one-quarter of participants exhibited persistent early knee OA symptoms based on KOOS thresholds from 6 to 12 months post-ACLR. Determining if this symptom persistence predicts worse long-term outcomes could inform the need for timely interventions after ACLR. Future researchers should examine if resolving persistent symptoms in this critical window improves later outcomes. Tracking early OA symptoms over time may identify high-risk patients who could benefit from early treatment.

Biomechanical changes in lower extremity in individuals with knee osteoarthritis in the past decade: A scoping review

Biomechanic studies can provide a powerful theoretical and scientific basis for studies on knee osteoarthritis (OA), which is of great significance for clinical management as it provides new concepts and methods in clinical and research settings. This study aimed to discuss and summarize biomechanical research on lower extremities in individuals with knee OA in the past ten years. The methodology of this review followed the framework outlined in the Joanna Briggs Institute (JBI) guidelines and strictly followed the checklist for drafting the findings. A literature search was conducted using PubMed, Scopus, Cochrane Library, Embase, Web of Science, Grey literature search in Open Library, and Google Academic databases. Relevant literature was searched from 2011 to 2023. Sixteen studies were included in this scoping review. Biomechanical research on knee OA in the last decade demonstrates that the biomechanics of the hip, knee, and ankle have a profound influence on the pathogenesis and treatment of knee OA. Individuals with knee OA have biomechanical changes in hip, knee, and ankle joints such as a significant defect in the strength of ankle varus muscles, weakness of hip abductor muscle, walking with toes outwards, increased knee adduction moment and angle, and decreased knee extensor moment. As the severity of knee OA increases, the tendency of hip abduction positions also increases. Further research with a longitudinal study design should focus on the determination of the relative importance of different biomechanical and neuromuscular factors in the development and progression of the disease.

Radiomics analysis of patellofemoral joint improves knee replacement risk prediction: Data from the Multicenter Osteoarthritis Study (MOST)

Objective

Knee replacement (KR) is the last-resort treatment for knee osteoarthritis. Although radiographic evidence of tibiofemoral joint has been widely adopted for prognostication, patellofemoral joint has gained little attention and may hold additional value for further improvements. We aimed to quantitatively analyse patellofemoral joint through radiomics analysis of lateral view radiographs for improved KR risk prediction.

Design

From the Multicenter Osteoarthritis Study dataset, we retrospectively retrieved the initial-visit lateral left knee radiographs of 2943 patients aged 50 to 79. They were split into training and test cohorts at a 2:1 ratio. A comprehensive set of radiomic features were extracted within the best-performing subregion of patellofemoral joint and combined into a radiomics score (RadScore). A KR risk score, derived from Kellgren-Lawrence grade (KLG) of tibiofemoral joint and RadScore of patellofemoral joint, was developed by multivariate Cox regression and assessed using time-dependent area under receiver operating characteristic curve (AUC).

Results

While patellofemoral osteoarthritis (PFOA) was insignificant during multivariate analysis, RadScore was identified as an independent risk factor (multivariate Cox p-value < 0.001) for KR. The subgroup analysis revealed that RadScore was particularly effective in predicting rapid progressor (KR occurrence before 30 months) among early- (KLG < 2) and mid-stage (KLG ​= ​2) patients. Combining two joints radiographic information, the AUC reached 0.89/0.87 for predicting 60-month KR occurrence.

Conclusions

The RadScore of the patellofemoral joint on lateral radiographs emerges as an independent prognostic factor for improving KR prognosis prediction. The KR risk score could be instrumental in managing progressive knee osteoarthritis interventions.

An interpretable knee replacement risk assessment system for osteoarthritis patients

Objective

Knee osteoarthritis (OA) is a complex disease with heterogeneous representations. Although it is modifiable to prevention and early treatment, there still lacks a reliable and accurate prognostic tool. Hence, we aim to develop a quantitative and self-administrable knee replacement (KR) risk stratification system for knee osteoarthritis (KOA) patients with clinical features.

Method

A total of 14 baseline features were extracted from 9592 cases in the Osteoarthritis Initiative (OAI) cohort. A survival model was constructed using the Random Survival Forests algorithm. The prediction performance was evaluated with the concordance index (C-index) and average receiver operating characteristic curve (AUC). A three-class KR risk stratification system was built to differentiate three distinct KR-free survival groups. Thereafter, Shapley Additive Explanations (SHAP) was introduced for model explanation.

Results

KR incidence was accurately predicted by the model with a C-index of 0.770 (±0.0215) and an average AUC of 0.807 (±0.0181) with 14 clinical features. Three distinct survival groups were observed from the ten-point KR risk stratification system with a four-year KR rate of 0.79%, 5.78%, and 16.2% from the low, medium, and high-risk groups respectively. KR is mainly caused by pain medication use, age, surgery history, diabetes, and a high body mass index, as revealed by SHAP.

Conclusion

A self-administrable and interpretable KR survival model was developed, underscoring a KR risk scoring system to stratify KOA patients. It will encourage regular self-assessments within the community and facilitate personalised healthcare for both primary and secondary prevention of KOA.

Sericin promotes chondrogenic proliferation and differentiation via glycolysis and Smad2/3 TGF-β signaling inductions and alleviates inflammation in three-dimensional models

Knee osteoarthritis is a chronic joint disease mainly characterized by cartilage degeneration. The treatment is challenging due to the lack of blood vessels and nerve supplies in cartilaginous tissue, causing a prominent limitation of regenerative capacity. Hence, we investigated the cellular promotional and anti-inflammatory effects of sericin, Bombyx mori-derived protein, on three-dimensional chondrogenic ATDC5 cell models. The results revealed that a high concentration of sericin promoted chondrogenic proliferation and differentiation and enhanced matrix production through the increment of glycosaminoglycans, COL2A1, COL X, and ALP expressions. SOX-9 and COL2A1 gene expressions were notably elevated in sericin treatment. The proteomic analysis demonstrated the upregulation of phosphoglycerate mutase 1 and triosephosphate isomerase, a glycolytic enzyme member, reflecting the proliferative enhancement of sericin. The differentiation capacity of sericin was indicated by the increased expressions of procollagen12a1, collagen10a1, rab1A, periostin, galectin-1, and collagen6a3 proteins. Sericin influenced the differentiation capacity via the TGF-β signaling pathway by upregulating Smad2 and Smad3 while downregulating Smad1, BMP2, and BMP4. Importantly, sericin exhibited an anti-inflammatory effect by reducing IL-1β, TNF-α, and MMP-1 expressions and accelerating COL2A1 production in the early inflammatory stage. In conclusion, sericin demonstrates potential in promoting chondrogenic proliferation and differentiation, enhancing cartilaginous matrix synthesis through glycolysis and TGF-β signaling pathways, and exhibiting anti-inflammatory properties.

CHMP5 attenuates osteoarthritis via inhibiting chondrocyte apoptosis and extracellular matrix degradation: involvement of NF-κB pathway

BACKGROUND

Osteoarthritis (OA), the most common joint disease, is linked with chondrocyte apoptosis and extracellular matrix (ECM) degradation. Charged multivesicular body protein 5 (CHMP5), a member of the multivesicular body, has been reported to serve as an anti-apoptotic protein to participate in leukemia development. However, the effects of CHMP5 on apoptosis and ECM degradation in OA remain unclear.

METHODS

In this study, quantitative proteomics was performed to analyze differential proteins between normal and OA patient articular cartilages. The OA mouse model was constructed by the destabilization of the medial meniscus (DMM). In vitro, interleukin-1 beta (IL-1β) was used to induce OA in human chondrocytes. CHMP5 overexpression and silencing vectors were created using an adenovirus system. The effects of CHMP5 on IL-1β-induced chondrocyte apoptosis were investigated by CCK-8, flow cytometry, and western blot. The effects on ECM degradation were examined by western blot and immunofluorescence. The potential mechanism was explored by western blot and Co-IP assays.

RESULTS

Downregulated CHMP5 was identified by proteomics in OA patient cartilages, which was verified in human and mouse articular cartilages. CHMP5 overexpression repressed cell apoptosis and ECM degradation in OA chondrocytes. However, silencing CHMP5 exacerbated OA chondrocyte apoptosis and ECM degradation. Furthermore, we found that the protective effect of CHMP5 against OA was involved in nuclear factor kappa B (NF-κB) signaling pathway.

CONCLUSIONS

This study demonstrated that CHMP5 repressed IL-1β-induced chondrocyte apoptosis and ECM degradation and blocked NF-κB activation. It was shown that CHMP5 might be a novel potential therapeutic target for OA in the future.

Development of radiographic knee osteoarthritis and the associations to radiographic changes and baseline variables in individuals with knee pain: a 2-year longitudinal study

OBJECTIVES

The aim was to study the development of radiographic knee osteoarthritis (RKOA) in individuals with knee pain over 2 years, and the associations between radiographic changes and baseline variables.

DESIGN

Longitudinal cohort study.

PARTICIPANTS AND SETTING

This study is part of the Halland Osteoarthritis cohort. The included 178 individuals, aged 30-67, had knee pain, without cruciate ligament injury or radiographic findings and 67% were women. The presence of RKOA was defined as Ahlbäck score of ≥1 in ≥1 knee. (Ahlbäck grade 1: joint space narrowing in the tibiofemoral joint <3 mm). Diagnosis of clinical KOA was based on the clinical guideline from the National Institute for Health and Care Excellence (NICE). Knee injury and Osteoarthritis Outcome Score (KOOS), pain intensity, physical function, body mass index (BMI) and visceral fat area (VFA) were measured. Associations to RKOA were analysed with logistic regression (OR).

RESULTS

In all, 13.8% (n=24) developed RKOA in 2 years whereof all had clinical KOA at baseline, as defined by NICE. Deterioration to RKOA was significantly associated with higher BMI, OR 1.119 (95% CI 1.024 to 1.223; p=0.013), and VFA, 1.008 (95% CI 1.000 to 1.016; p=0.049), worse knee pain intensity, 1.238 (95% CI 1.028 to 1.490; p=0.024), worse scores for KOOS Pain, 0.964 (95% CI 0.937 to 0.992; p=0.013) and KOOS Symptoms, 0.967 (95% CI 0.939 to 0.996; p=0.027), KOOS Activities of daily living 0.965 (95% CI 0.935 to 0.996; p=0.026) and KOOS Quality of Life 0.973 (95% CI 0.947 to 0.999; p=0.044), at baseline.

CONCLUSIONS

One out of seven individuals with clinical KOA developed RKOA in only 2 years. Baseline variables associated with RKOA after 2 years may possibly be detected early by using the NICE guideline, assessment of obesity and self-reported data of symptoms to support first-line treatment: education, exercise and weight control.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04928170).

The osteoarthritis prevention study (TOPS) - A randomized controlled trial of diet and exercise to prevent Knee Osteoarthritis: Design and rationale

Background

Osteoarthritis (OA), the leading cause of disability among adults, has no cure and is associated with significant comorbidities. The premise of this randomized clinical trial is that, in a population at risk, a 48-month program of dietary weight loss and exercise will result in less incident structural knee OA compared to control.

Methods/design

The Osteoarthritis Prevention Study (TOPS) is a Phase III, assessor-blinded, 48-month, parallel 2 arm, multicenter randomized clinical trial designed to reduce the incidence of structural knee OA. The study objective is to assess the effects of a dietary weight loss, exercise, and weight-loss maintenance program in preventing the development of structural knee OA in females at risk for the disease. TOPS will recruit 1230 ambulatory, community dwelling females with obesity (Body Mass Index (BMI) ​≥ ​30 ​kg/m2) and aged ≥50 years with no radiographic (Kellgren-Lawrence grade ≤1) and no magnetic resonance imaging (MRI) evidence of OA in the eligible knee, with no or infrequent knee pain. Incident structural knee OA (defined as tibiofemoral and/or patellofemoral OA on MRI) assessed at 48-months from intervention initiation using the MRI Osteoarthritis Knee Score (MOAKS) is the primary outcome. Secondary outcomes include knee pain, 6-min walk distance, health-related quality of life, knee joint loading during gait, inflammatory biomarkers, and self-efficacy. Cost effectiveness and budgetary impact analyses will determine the value and affordability of this intervention.

Discussion

This study will assess the efficacy and cost effectiveness of a dietary weight loss, exercise, and weight-loss maintenance program designed to reduce incident knee OA.

Trial registration

ClinicalTrials.gov Identifier: NCT05946044.

Danggui-Shaoyao-San (DSS) ameliorates the progression of osteoarthritis via suppressing the NF-κB signaling pathway: an in vitro and in vivo study combined with bioinformatics analysis

BACKGROUND

Osteoarthritis (OA) is a common chronic age-related joint disease characterized primarily by inflammation of synovial membrane and degeneration of articular cartilage. Accumulating evidence has demonstrated that Danggui-Shaoyao-San (DSS) exerts significant anti-inflammatory effects, suggesting that it may play an important role in the treatment of knee osteoarthritis (KOA).

METHODS

In the present study, DSS was prepared and analyzed by high-performance liquid chromatography (HPLC). Bioinformatics analyses were carried out to uncover the functions and possible molecular mechanisms by which DSS against KOA. Furthermore, the protective effects of DSS on lipopolysaccharide (LPS)-induced rat chondrocytes and cartilage degeneration in a rat OA model were investigated in vivo and in vitro.

RESULTS

In total, 114 targets of DSS were identified, of which 60 candidate targets were related to KOA. The target enrichment analysis suggested that the NF-κB signaling pathway may be an effective mechanism of DSS. In vitro, we found that DSS significantly inhibited LPS-induced upregulation of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin-6 (IL-6), matrix metalloproteinase-3 (MMP3), and matrix metalloproteinase-13 (MMP13). Meanwhile, the degradation of collagen II was also reversed by DSS. Mechanistically, DSS dramatically suppressed LPS-induced activation of the nuclear factor kappa B (NF-κB) signaling pathway. In vivo, DSS treatment prevented cartilage degeneration in a rat OA model.

CONCLUSIONS

DSS could ameliorate the progression of OA through suppressing the NF-κB signaling pathway. Our findings indicate that DSS may be a promising therapeutic approach for the treatment of KOA.

A scoping review of patient self-report measures of flare in knee and hip osteoarthritis (OA): A report from the OMERACT flares in OA working group

PURPOSE

We aimed to analyze the content validity/domain match and feasibility of self-report instruments that could measure flare in osteoarthritis (OA), by extending our 2017 literature review on the definition of flare in knee and hip OA.

METHOD

We searched PubMed (Medline), Web of Science and PsycInfo (Ebsco Host) databases for original articles reporting research about flare (or synonyms) in humans with knee and hip OA, between 2017 and 2023. Four experts worked independently, checking the records, and assessing content validity and feasibility, writing justification for exclusion.

RESULTS

At literature review phase, 575 papers were filtered. After experts' analysis, 59 studies were included, and 44 instruments associated with flare in OA were identified. Most were studies about pain in knee or hip OA (35 %), cultural adaptation of a measure (33 %) or studies investigating psychometric properties of full (16 %) or short form (4 %) instruments. The assessment of domain match and feasibility revealed that 15 instruments were assigned a label of 'yes' or 'uncertain' as to whether or not there was a good match with the domain concept or whether the instrument was considered feasible to use.

DISCUSSION

Most identified instruments considered different aspects of pain and the associated discomfort in performing daily activities but did not include the central aspects of flare in OA, i.e. the change of state, nor the additional Outcome Measures in Rheumatology (OMERACT) endorsed domains for OA flare namely stiffness, swelling, psychological aspects, impact of symptoms including fatigue and sleep disturbance. Although it is possible that the period specified to conduct this literature review may have led to some recognized instruments being excluded, this review demonstrates the need for the research community to reach consensus on the best way to measure self-reported flares in future clinical trials and observational studies.

Advances in the application of wearable sensors for gait analysis after total knee arthroplasty: a systematic review

BACKGROUND

Wearable sensors have become a complementary means for evaluation of body function and gait in lower limb osteoarthritis. This study aimed to review the applications of wearable sensors for gait analysis after total knee arthroplasty (TKA).

METHODS

Five databases, including Web of Science Core Collection, Embase, Cochrane, Medline, and PubMed, were searched for articles published between January 2010 and March 2023, using predetermined search terms that focused on wearable sensors, TKA, and gait analysis as broad areas of interest.

RESULTS

A total of 25 articles were identified, involving 823 TKA patients. Methodologies varied widely across the articles, with inconsistencies found in reported patient characteristics, sensor data and experimental protocols. Patient-reported outcome measures (PROMs) and gait variables showed various recovery times from 1 week postoperatively to 5 years postoperatively. Gait analysis using wearable sensors and PROMs showed differences in controlled environments, daily life, and when comparing different surgeries.

CONCLUSION

Wearable sensors offered the potential to remotely monitor the gait function post-TKA in both controlled environments and patients' daily life, and covered more aspects than PROMs. More cohort longitudinal studies are warranted to further confirm the benefits of this remote technology in clinical practice.

Vitamin D and autophagy in knee osteoarthritis: A review

Knee osteoarthritis (KOA), the highly prevalent degenerative disease affecting the joint, perpetually devastates the health of the elderly. Of various mechanisms known to participate in KOA etiology, apoptosis of chondrocytes is widely regarded as the primary cause of cartilage degradation. It has been suggested that the induction of autophagy in chondrocytes could potentially prolong the progression of KOA by modulating intracellular metabolic processes, which may be helpful for ameliorating chondrocyte apoptosis and eventual cartilage degeneration. Autophagy, a physiological process characterized by intracellular self-degradation, has been reportedly implicated in various pathologic conditions including KOA. Interestingly, vitamin D has been shown to regulate autophagy in human chondrocytes through multiple pathways, specifically AMPK/mTOR signaling pathway. This observation underscores the potential of vitamin D as a novel approach for restoring the functionality and survivability of chondrocytes in KOA. Supporting vitamin D's clinical significance, previous studies have demonstrated its substantial involvement in the symptoms and irregular joint morphology observed in KOA patients, strengthening potential therapeutic efficacy of vitamin D in treatment of KOA. Herein, the purpose of this review was to determine the mechanisms underlying the multi-processes of vitamin D implicated in autophagy in several cells including chondrocytes, which would bring unique insights into KOA pathogenesis.

Reflections from the OARSI 2022 clinical trials symposium: The pain of OA-Deconstruction of pain and patient-reported outcome measures for the benefit of patients and clinical trial design

OBJECTIVE

Osteoarthritis (OA) drug development is hampered by a number of challenges. One of the main challenges is the apparent discordance between pain and structure, which has had a significant impact on drug development programs and has led to hesitance among stakeholders. Since 2017, the Clinical Trials Symposium (CTS) has been hosted under the Osteoarthritis Research Society International (OARSI) leadership. OARSI and the CTS steering committee yearly invite and encourage discussions on selected special subject matter between regulators, drug developers, clinicians, clinical researchers, biomarker specialists, and basic scientists to progress drug development in the OA field.

METHOD

The main topic for the 2022 OARSI CTS was to elucidate the many facets of pain in OA and to enable a discussion between regulators (Food and Drug Administration (FDA) and the European Medicines Agency (EMA)) and drug developers to clarify outcomes and study designs for OA drug development.

RESULTS

Signs or symptoms indicative of nociceptive pain occur in 50-70% of OA patients, neuropathic-like pain in 15-30% of patients, and nociplastic pain in 15-50% of patients. Weight-bearing knee pain is associated with bone marrow lesions and effusions. There are currently no simple objective functional tests whose improvements correlate with patient perceptions.

CONCLUSIONS

The CTS participants, in collaboration with the FDA and EMA, raised several suggestions that they consider key to future clinical trials in OA including the need for more precise differentiation of pain symptoms and mechanisms, and methods to reduce placebo responses in OA trials.

Knee- and Overall Health-Related Quality of Life Following Anterior Cruciate Ligament Injury: A Cross-sectional Analysis of Australian and Canadian Cohorts

OBJECTIVE: To describe the knee- and overall health-related quality of life (QOL) 3 to 12 years after anterior cruciate ligament (ACL) tear, and to assess the association of clinical and structural features with QOL after ACL tear. DESIGN: Cross-sectional analysis of combined data from Australian (n = 76, 5.4 years postinjury) and Canadian (n = 50, 6.6 years postinjury) prospective cohort studies. METHODS: We conducted a secondary analysis of patient-reported outcomes and index knee magnetic resonance imaging (MRI) acquired in 126 patients (median 5.5 [range: 4-12] years postinjury), all treated with ACL reconstruction. Outcomes included knee (ACL Quality of Life questionnaire [ACL-QOL]) and overall health-related QOL (EQ-5D-3L). Explanatory variables were self-reported knee pain (Knee Injury and Osteoarthritis Outcome Score [KOOS-Pain subscale]) and function (KOOS-Sport subscale), and any knee cartilage lesion (MRI Osteoarthritis Knee Score). Generalized linear models were adjusted for clustering between sites. Covariates were age, sex, time since injury, injury type, subsequent knee injuries, and body mass index. RESULTS: The median [range] ACL-QOL score was 82 [24-100] and EQ-5D-3L was 1.0 [-0.2 to 1.0]. For every 10-point higher KOOS-Sport score, the ACL-QOL score increased by 3.7 points (95% confidence interval [CI]: 1.7, 5.7), whereas there was no evidence of an association with the EQ-5D-3L (0.00 points, 95% CI: -0.02, 0.02). There were no significant association between KOOS-Pain and ACL-QOL (4.9 points, 95% CI: -0.1, 9.9) or EQ-5D-3L (0.05 points, 95% CI: -0.01, 0.11), respectively. Cartilage lesions were not associated with ACL-QOL (-1.2, 95% CI: -5.1, 2.7) or EQ-5D-3L (0.01, 95% CI: -0.01, 0.04). CONCLUSION: Self-reported function was more relevant for knee-related QOL than knee pain or cartilage lesions after ACL tear. Self-reported function, pain, and knee structural changes were not associated with overall health-related QOL. J Orthop Sports Phys Ther 2023;53(7):1-12. Epub: 8 June 2023. doi:10.2519/jospt.2023.11838.

Biomarkers for osteoarthritis: Current status and future prospects

Osteoarthritis (OA) is the most common form of arthritis globally and a major cause of pain, physical disability, and loss of economic productivity, with currently no causal treatment available. This review article focuses on current research on OA biomarkers and the potential for using biomarkers in future clinical practice and clinical trials of investigational drugs. We discuss how biomarkers, specifically soluble ones, have a long path to go before reaching clinical standards of care. We also discuss how biomarkers can help in phenotyping and subtyping to achieve enhanced stratification and move toward better-designed clinical trials. We also describe how biomarkers can be used for molecular endotyping and for determining the clinical outcomes of investigational cell-based therapies. Biomarkers have the potential to be developed as surrogate end points in clinical trials and help private-public consortia and the biotechnology and pharmaceutical industries develop more effective and targeted personalized treatments and enhance clinical care for patients with OA.

Tetrandrine Represses Inflammation and Attenuates Osteoarthritis by Selective Inhibition of COX-2

OBJECTIVE

There is a lack of effective and long-term safe drugs for the treatment of osteoarthritis (OA). Tetrandrine (Tet) has been approved and used to treat rheumatoid arthritis for several decades, but its effect on OA has not been investigated. Herein, we explored the effect of Tet on OA and its underlying mechanism.

METHODS

OA was induced using destabilization of the medial meniscus (DMM) in C57BL/6J mice. The animals were randomly divided into sham, DMM, Tet, celecoxib (CXB), and indomethacin (INDO) groups. Each group was given solvent or corresponding drugs by gavage for 7 weeks after convalescence. Pathological staining, OARSI scores, micro-computed tomography and behavior tests were performed to evaluate the effects of Tet.

RESULTS

Tet remarkably alleviated cartilage injury in the knee joint, limited bone remodeling in the subchondral bone, and delayed progression of OA. Tet also significantly relieved joint pain and maintained function. Further mechanistic studies revealed that Tet lowered inflammatory cytokine levels and selectively suppressed gene and protein expression of cyclooxygenase (COX)-2 but not COX-1 (P<0.01). Tet also reduced the production of prostaglandin E2 without damaging the gastric mucosa.

CONCLUSION

We found that Tet could selectively inhibit COX-2 gene expression and decrease cytokine levels in mice, thus reducing inflammation and improving OA without obvious gastric adverse events. These results provide a scientific basis for the clinical application of Tet in the treatment of OA.

Peak Tibiofemoral Contact Forces Estimated Using IMU-Based Approaches Are Not Significantly Different from Motion Capture-Based Estimations in Patients with Knee Osteoarthritis

Altered tibiofemoral contact forces represent a risk factor for osteoarthritis onset and progression, making optimization of the knee force distribution a target of treatment strategies. Musculoskeletal model-based simulations are a state-of-the-art method to estimate joint contact forces, but they typically require laboratory-based input and skilled operators. To overcome these limitations, ambulatory methods, relying on inertial measurement units, have been proposed to estimated ground reaction forces and, consequently, knee contact forces out-of-the-lab. This study proposes the use of a full inertial-capture-based musculoskeletal modelling workflow with an underlying probabilistic principal component analysis model trained on 1787 gait cycles in patients with knee osteoarthritis. As validation, five patients with knee osteoarthritis were instrumented with 17 inertial measurement units and 76 opto-reflective markers. Participants performed multiple overground walking trials while motion and inertial capture methods were synchronously recorded. Moderate to strong correlations were found for the inertial capture-based knee contact forces compared to motion capture with root mean square error between 0.15 and 0.40 of body weight. The results show that our workflow can inform and potentially assist clinical practitioners to monitor knee joint loading in physical therapy sessions and eventually assess long-term therapeutic effects in a clinical context.

Development and evaluation of nomograms for predicting osteoarthritis progression based on MRI cartilage parameters: data from the FNIH OA biomarkers Consortium

BACKGROUND

Osteoarthritis (OA) is a leading cause of disability worldwide. However, the existing methods for evaluating OA patients do not provide enough comprehensive information to make reliable predictions of OA progression. This retrospective study aimed to develop prediction nomograms based on MRI cartilage that can predict disease progression of OA.

METHODS

A total of 600 subjects with mild-to-moderate osteoarthritis from the Foundation for National Institute of Health (FNIH) project of osteoarthritis initiative (OAI). The MRI cartilage parameters of the knee at baseline were measured, and the changes in cartilage parameters at 12- and 24-month follow-up were calculated. The least absolute shrinkage and selection operator (LASSO) regression analysis was used to extract the valuable characteristic parameters at different time points including cartilage thickness, cartilage volume, subchondral bone exposure area and uniform cartilage thickness in different sub regions of the knee, and the MRI cartilage parameters score0, scoreΔ12, and scoreΔ24 at baseline, 12 months, and 24 months were constructed. ScoreΔ12, and scoreΔ24 represent changes between 12 M vs. baseline, and 24 M vs. baseline, respectively. Logistic regression analysis was used to construct the nomogram0, nomogramΔ12, and nomogramΔ24, including MRI-based score and risk factors. The area under curve (AUC) was used to evaluate the differentiation of nomograms in disease progression and subgroup analysis. The calibration curve and Hosmer-Lemeshow (H-L) test were used to verify the calibration of the nomograms. Clinical usefulness of each prediction nomogram was verified by decision curve analysis (DCA). The nomograms with predictive efficacy were analyzed by secondary analysis. Internal verification was assessed using bootstrapping validation.

RESULTS

Each nomogram included cartilage score, KL grade, WOMAC pain score, WOMAC disability score, and minimum joint space width. The AUC of nomogram0, nomogramΔ12, and nomogramΔ24 in predicing the progression of radiology and pain were 0.69, 0.64, and 0.71, respectively. All three nomograms had good calibration. Analysis by DCA showed that the clinical effectiveness of nomogramΔ24 was higher than others. Secondary analysis showed that nomogram0 and nomogramΔ24 were more capable of predicting OA radiologic progression than pain progression.

CONCLUSION

Nomograms based on MRI cartilage change were useful for predicting the progression of mild to moderate OA.

Early knee OA definition-what do we know at this stage? An imaging perspective

While criteria for early-stage knee osteoarthritis (OA) in a primary care setting have been proposed, the role of imaging has been limited to radiography using the standard Kellgren-Lawrence classification. Standardized imaging and interpretation are critical with radiographs, yet studies have also shown that even early stages of radiographic OA already demonstrate advanced damage to knee joint tissues such as cartilage, menisci, and bone marrow. Morphological magnetic resonance imaging (MRI) shows degenerative damage earlier than radiographs and definitions for OA using MRI have been published though no accepted definition of early OA based on MRI is currently available. The clinical significance of structural abnormalities has also not been well defined, and the differentiation between normal aging and structural OA development remains a challenge. Compositional MRI of cartilage provides information on biochemical, degenerative changes within the cartilage matrix before cartilage defects occur and when cartilage damage is potentially reversible. Studies have shown that cartilage composition can predict cartilage loss and radiographic OA. However, while this technology is most promising for characterizing early OA it has currently limited clinical application. Better standardization of compositional MRI is required, which is currently work in progress. Finally, there has been renewed interest in computed tomography (CT) for assessing early knee OA as new techniques such as weight bearing and spectral CT are available, which may provide information on joint loading, cartilage, and bone and potentially have a role in better characterizing early OA. In conclusion, while imaging may have a limited role in diagnosing early OA in a primary care setting, there are advanced imaging technologies available, which detect early degeneration and may thus significantly alter management as new therapeutic modalities evolve.

Potential surrogate outcomes in individuals at high risk for incident knee osteoarthritis

OBJECTIVE

To study potential surrogate outcomes for osteoarthritis (OA) incidence by evaluating the association of short-term changes in clinical and imaging biomarkers with long-term clinical knee OA incidence.

DESIGN

Middle-aged women with overweight/obesity, but free of knee symptoms were recruited through their general practitioners. At baseline, after 2.5 years, and after 6.5 years, questionnaires, physical examination, radiographs, and Magnetic resonance imaging (MRI) scans were obtained. The percentage of knees with a minimal clinically important difference for knee pain severity, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain/stiffness/function, and joint space narrowing, and of those with progression/regression of medial knee alignment, chronic knee pain, radiographic osteophytes, and cartilage defects, bone marrow lesions, osteophytes, and effusion/synovitis on MRI were determined. For each of these potential surrogate outcomes with ≥10% improvement or progression in the population over 2.5 years, the association with incident clinical knee OA, defined using the combined ACR-criteria, after 6.5 years was determined.

RESULTS

Most pre-defined potential surrogate outcomes showed ≥10% change in the population over 2.5 years, but only worsening of TF cartilage defects, worsening of TF osteophytes on MRI, and an increase in pain severity were significantly associated with greater clinical knee OA incidence after 6.5 years. These potential surrogate outcomes had high specificity and negative predictive value (89-91%) and low sensitivity and positive predictive value (20-28%) CONCLUSIONS: Worsening of TF cartilage defects and TF osteophytes on MRI, and increased pain severity could be seen as surrogate outcomes for long-term OA incidence. However, higher positive predictive values seem warranted for the applicability of these factors in future preventive trials.

Early Osteoarthritis Questionnaire (EOAQ): a tool to assess knee osteoarthritis at initial stage

Background

Early stage of osteoarthritis (OA) is characterized by joint stiffness and pain as well as by subclinical structural changes that may affect cartilage, synovium, and bone. At the moment, the lack of a validated definition of early osteoarthritis (EOA) does not allow to make an early diagnosis and adopt a therapeutic strategy to slow disease progression. Also, no questionnaires are available to evaluate the early stage, and therefore this remains an unmet need.

Objective

Therefore, the purpose of the technical experts panel (TEP) of 'International Symposium of intra-articular treatment' (ISIAT) was to create a specific questionnaire to evaluate and monitor the follow-up and clinical progress of patients affected by early knee OA.

Design

The items for the Early Osteoarthritis Questionnaire (EOAQ) were identified according to the following steps: items generation, items reduction, and pre-test submission.

Methods

During the first step, literature has been reviewed and a comprehensive list of items about pain and function in knee EOA was drafted. Then, during the ISIAT (5th edition 2019), the draft has been discussed by the board, which reformulated, deleted, or subdivided some of the items. After the ISIAT symposium, the draft was submitted to 24 subjects affected by knee OA. A score based on the importance and the frequency was created and the items with a score ⩾0.75 were selected. After intermediate evaluation made by a sample of patients, the second and final version of the questionnaire EOAQ was submitted to the whole board for final analysis and acceptance in a second meeting (29 January 2021).

Results

After an exhaustive elaboration, the final version of the questionnaire contains two domains (Clinical Features and Patients Reported Outcome) with respectively 2 and 9 questions, for a total of 11 questions. Questions mainly explored the fields of early symptoms and patients reported outcomes. Marginally, the need of the symptoms treatment and the use of painkillers were investigated.

Conclusions

Adoption of diagnostic criteria of early OA is strongly encouraged and a specific questionnaire for the whole management of the clinical features and patients' outcome might really improve the evolution of OA in the early stages of the disease, when the treatment is expected to be more effective.

Targeting FoxO transcription factors with HDAC inhibitors for the treatment of osteoarthritis

OBJECTIVES

Osteoarthritis (OA) features ageing-related defects in cellular homeostasis mechanisms in articular cartilage. These defects are associated with suppression of forkhead box O (FoxO) transcription factors. FoxO1 or FoxO3 deficient mice show early onset OA while FoxO1 protects against oxidative stress in chondrocytes and promotes expression of autophagy genes and the essential joint lubricant proteoglycan 4 (PRG4). The objective of this study was to identify small molecules that can increase FoxO1 expression.

METHODS

We constructed a reporter cell line with FoxO1 promoter sequences and performed high-throughput screening (HTS) of the Repurposing, Focused Rescue and Accelerated Medchem (ReFRAME) library . Hits from the HTS were validated and function was assessed in human chondrocytes, meniscus cells and synoviocytes and following administration to mice. The most promising hit, the histone deacetylase inhibitor (HDACI) panobinostat was tested in a murine OA model.

RESULTS

Among the top hits were HDACI and testing in human chondrocytes, meniscus cells and synoviocytes showed that panobinostat was the most promising compound as it increased the expression of autophagy genes and PRG4 while suppressing the basal and IL-1β induced expression of inflammatory mediators and extracellular matrix degrading enzymes. Intraperitoneal administration of panobinostat also suppressed the expression of mediators of OA pathogenesis induced by intra-articular injection of IL-1β. In a murine OA model, panobinostat reduced the severity of histological changes in cartilage, synovium and subchondral bone and improved pain behaviours.

CONCLUSION

Panobinostat has a clinically relevant activity profile and is a candidate for OA symptom and structure modification.

Dendrobine Alleviates Cellular Senescence and Osteoarthritis via the ROS/NF-κB Axis

Osteoarthritis (OA) is a degenerative joint disease characterized by low-grade inflammation and cartilage degradation. Dendrobine (DEN) is reported to inhibit inflammation and oxidative stress in some diseases, but its role in chondrocyte senescence and OA progress has not yet been elucidated. Our study aimed to explore the protective effects of DEN on OA both in vitro and in vivo. We found that DEN inhibited extracellular matrix (ECM) degradation and promoted ECM synthesis. Meanwhile, DEN inhibited senescence-associated secretory phenotype (SASP) factors expression and senescence phenotype in IL-1β-treated chondrocytes. Furthermore, DEN improved mitochondrial function and reduced the production of intracellular reactive oxygen species (ROS). Also, DEN suppressed IL-1β-induced activation of the NF-κB pathway. Further, using NAC (ROS inhibitor), we found that DEN might inhibit NF-κB cascades by reducing ROS. Additionally, X-ray, micro-CT, and histological analyses in vivo demonstrated that DEN significantly alleviated cartilage inflammation, ECM degradation, and subchondral alterations in OA progression. In conclusion, DEN inhibits SASP factors expression and senescence phenotype in chondrocytes and alleviated the progression of OA via the ROS/NF-κB axis, which provides innovative strategies for the treatment of OA.

The KNee OsteoArthritis Prediction (KNOAP2020) challenge: An image analysis challenge to predict incident symptomatic radiographic knee osteoarthritis from MRI and X-ray images

OBJECTIVES

The KNee OsteoArthritis Prediction (KNOAP2020) challenge was organized to objectively compare methods for the prediction of incident symptomatic radiographic knee osteoarthritis within 78 months on a test set with blinded ground truth.

DESIGN

The challenge participants were free to use any available data sources to train their models. A test set of 423 knees from the Prevention of Knee Osteoarthritis in Overweight Females (PROOF) study consisting of magnetic resonance imaging (MRI) and X-ray image data along with clinical risk factors at baseline was made available to all challenge participants. The ground truth outcomes, i.e., which knees developed incident symptomatic radiographic knee osteoarthritis (according to the combined ACR criteria) within 78 months, were not provided to the participants. To assess the performance of the submitted models, we used the area under the receiver operating characteristic curve (ROCAUC) and balanced accuracy (BACC).

RESULTS

Seven teams submitted 23 entries in total. A majority of the algorithms were trained on data from the Osteoarthritis Initiative. The model with the highest ROCAUC (0.64 (95% confidence interval (CI): 0.57-0.70)) used deep learning to extract information from X-ray images combined with clinical variables. The model with the highest BACC (0.59 (95% CI: 0.52-0.65)) ensembled three different models that used automatically extracted X-ray and MRI features along with clinical variables.

CONCLUSION

The KNOAP2020 challenge established a benchmark for predicting incident symptomatic radiographic knee osteoarthritis. Accurate prediction of incident symptomatic radiographic knee osteoarthritis is a complex and still unsolved problem requiring additional investigation.

Changes of the subchondral bone microchannel network in early osteoarthritis

OBJECTIVE

We have identified a 3D network of subchondral microchannels that connects the deep zone of cartilage to the bone marrow (i.e., cartilage-bone marrow microchannel connectors; CMMC). However, the pathological significance of CMMC is largely unknown. Here, we quantitatively evaluated how the CMMC microarchitecture is related to cartilage condition, as well as regional differences in early idiopathic osteoarthritis (OA).

METHODS

Two groups of cadaveric female human femoral heads (intact cartilage vs early cartilage lesions) were identified, and a biopsy-based high-resolution micro-CT imaging was employed. Subchondral bone (SB) thickness, CMMC number, maximum and minimum CMMC size, and the CMMC morphology were quantified and compared between the two groups. The effect of joint's region and cartilage condition was examined on each dependent variable.

RESULTS

The CMMC number and morphology were affected by region of the joint, but not by cartilage condition. On the other hand, the minimum and maximum CMMC size was changed by both the location on the joint, as well as the cartilage condition. The smallest CMMC were consistently detected at the load-bearing region (LBR) of the joint. Compared to non-pathological subjects, the size of the microchannels was enlarged in early OA, most noticeably at the non-load-bearing region (NLBR) and the peripheral rim (PR) of the femoral head. Furthermore, subchondral bone thinning was observed in early OA as a localized occurrence linked with areas of partial chondral defect.

CONCLUSION

Our data point to an enlargement of the SB microchannel network, and a collective structural deterioration of SB in early idiopathic OA.

N6 -methyladenosine-modified circRNA RERE modulates osteoarthritis by regulating β-catenin ubiquitination and degradation

OBJECTIVES

N⁶ -methyladenosine (m6A) is one of the most abundant internal RNA modifications. We investigated the role of m6A-modified circRERE in osteoarthritis (OA) and its mechanism.

MATERIALS AND METHODS

CircRERE and IRF2BPL were screened by microarrays. The role of m6A-modification in circRERE was examined by methylated RNA precipitation and morpholino oligo (MOs) treatment. The axis of circRERE/miR-195-5p/IRF2BPL/β-catenin was determined using flow cytometry, western blotting and immunofluorescence in human chondrocytes (HCs) and corroborated using a mouse model of destabilization of medial meniscus (DMM) with intra-articular (IA) injection of adeno-associated viruses (AAV).

RESULTS

CircRERE was decreased in OA cartilage and chondrocytes compared with control. CircRERE downregulation was likely attributed to its increased m6A modification prone to endoribonucleolytic cleavage by YTHDF2-HRSP12-RNase P/MRP in OA chondrocytes. MOs transfection targeting HRSP12 binding motifs in circRERE partially reversed decreased circRERE expression and increased apoptosis in HCs treated with IL-1β for 6 h. CircRERE exerted chondroprotective effects by targeting miR-195-5p/IRF2BPL, thus regulating the ubiquitination and degradation of β-catenin. CircRere (mouse homologue) overexpression by IA-injection of AAV-circRere into mice attenuated the severity of DMM-induced OA, whereas AAV-miR-195a-5p or AAV-sh-Irf2bpl reduced the protective effects. The detrimental effects of AAV-sh-Irf2bpl on DMM-induced OA were substantially counteracted by ICG-001, an inhibitor of β-catenin.

CONCLUSIONS

Our study is a proof-of-concept demonstration for targeting m6A-modified circRERE and its target miR-195-5p/IRF2BPL/β-catenin as potential therapeutic strategies for OA treatment.

Validity of the Osteoarthritis Research Society International (OARSI) recommended performance-based tests of physical function in individuals with symptomatic Kellgren and Lawrence grade 0-2 knee osteoarthritis

BACKGROUND

Performance-based physical tests have been widely used as objective assessments for individuals with knee osteoarthritis (KOA), and the core set of tests recommended by the Osteoarthritis Research Society International (OARSI) aims to provide reliable, valid, feasible and standardized measures for clinical application. However, few studies have documented their validity in roentgenographically mild KOA. Our goal was to test the validity of five performance-based tests in symptomatic KOA patients with X-ray findings of Kellgren and Lawrence (K-L) grade 0-2.

METHODS

We recruited a convenience sample of thirty KOA patients from outpatient clinics and 30 age- and sex-matched asymptomatic controls from the community. They performed five OARSI-recommended physical tests and the KOA group answered the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. The tests included the 9-step stair-climbing test (9 s-SCT), timed up and go (TUG) test, 30-second chair-stand test (30sCST), 40-m fast walking-test (40MFPW) and 6-minute walking test (6MWT). The discriminant validity of these physical tests were assessed by comparisons between the KOA and control groups, receiver operating curve and multivariate logistic regression analysis. The convergent/divergent validity was assessed by correlation between the physical tests results and the three subscale scores of the WOMAC in the KOA group.

RESULTS

The KOA group had significantly worse performance than the control group. The percentage of difference was the largest in the 9 s-SCT (57.2%) and TUG tests (38.4%). Meanwhile, Cohen's d was above 1.2 for the TUG test and 6MWT (1.2 ~ 2.0), and between 0.8 and 1.2 for the other tests. The areas under the curve to discriminate the two groups were mostly excellent to outstanding, except for the 30sCST. Convergent validity was documented with a moderate correlation between the 9 s-SCT and the physical function (WOMAC-PF) subscale scores (Spearman's ρ = 0.60).

CONCLUSIONS

The OARSI recommended core set was generally highly discriminative between people with K-L grade 0-2 KOA and their controls, but convergent/divergent validity was observed only in the 9 s-SCT. Further studies are required to evaluate the responsiveness of these tests and understand the discordance of physical performance and self-reported measures.

Effusion detected by ultrasonography and overweight may predict the risk of knee osteoarthritis in females with early knee osteoarthritis: a retrospective analysis of Iwaki cohort data

BACKGROUND

Knee osteoarthritis (OA) has enormous medical and socioeconomic burdens, which early diagnosis and intervention can reduce. We investigated the influence of knee effusion on the progression of knee OA in patients with early knee OA.

METHODS

A total of 404 participants without radiographic knee OA were assessed from a 3-year longitudinal analysis. Participants were classified into non-OA and early knee OA groups. The effusion area (mm²) was quantified using ultrasonography. Receiver operating characteristic and logistic regression analyses were performed.

RESULTS

At the 3-year follow-up, 114 of 349 knees (32%) had progressed from non-OA and 32 of 55 knees (58%) had progressed from early knee OA to radiographic knee OA. Logistic regression analysis showed that female sex (odds ratio [OR] 3.36, 95% confidence interval [CIs] 2.98-5.42), early knee OA (OR 2.02, 95% CI 1.08-3.75), body mass index (OR 1.11, 95% CI 1.02-1.19), and effusion area (OR 1.01, 95% CI 1.01-1.02) were significantly correlated with knee OA progression. Women who were overweight (body mass index ≥ 25 kg/m²) with more severe effusion had a higher risk of OA progression (area under the curve = 0.691, OR = 6.00) compared to those not overweight (area under the curve = 0.568, OR = 1.91).

CONCLUSION

Knee effusion may be an indicator of the progression of early-stage knee OA.

Identification of Early Knee Osteoarthritis Based on Knee Joint Trajectory during Stair Climbing

Patients with knee osteoarthritis show low stair climbing ability, but a diagnosis of stair performance time is not enough to identify the early stages of knee osteoarthritis. Therefore, we developed an indicator named range of the knee joint trajectory (RKJT) as a kinematic parameter to express more detailed characteristics than stair performance time. To achieve this, we used our developed "IR-Locomotion", a markerless measurement system that can track the knee joint trajectory when climbing stairs. This study aimed to test whether the RKJT effectively identifies patients with early knee osteoarthritis even after controlling stair performance time. Forty-seven adults with moderate to severe knee pain (mean age 59.2 years; 68.1% women) underwent the radiographic examination (Kellgren and Lawrence grade) of both knees and a stair climbing test on 11 stairs. The RKJT during the stair climbing test was calculated by "IR-Locomotion". A generalized linear mixed model was used to evaluate the discriminative capability of RKJT on early knee osteoarthritis (i.e., Kellgren and Lawrence grade of 1). As expected, patients with early knee osteoarthritis showed larger RKJT than non-radiographic controls (95% confidence interval: 1.007, 1.076). Notably, this finding was consistent even after adjusting stair performance time.

Phosphoproteomics reveals the BRAF-ERK1/2 axis as an important pathogenic signaling node in cartilage degeneration

OBJECTIVE

Osteoarthritis (OA) causes gradual cellular alterations, structural anomalies and joint dysfunction. Progressive decline of chondrocyte function plays a vital role on OA pathogenesis. Although protein phosphorylation controls cartilage metabolism, its regulation mechanism in OA remains unclear. Thus, proteomic methods were used to investigate phosphorylation changes in preserved and OA articular cartilage samples, and to explore the intervention targets of phosphorylated kinase.

METHODS

Preserved (control) and lesioned (OA) cartilage samples from OA cases were assessed by phosphoproteomics. Immobilized metal affinity chromatography was performed for phosphopeptide enrichment. Quantitated phosphosites were comparatively assessed in the cartilage sample pair. Kinase-substrate enrichment analyses were carried out for identifying OA-related kinases. BRAF expression in cartilage tissues was assessed by immunohistochemical staining. The effects of BRAF inhibitor on cartilage degeneration were examined in mouse chondrocytes and OA mouse model.

RESULTS

High-sensitivity mass spectrometry-based proteomics revealed 7,471 peptides and 4,375 phosphorylated peptides differing between preserved and lesioned cartilage samples, which represented the significant alteration of kinase hubs and transduction pathways. Phosphoproteomics identified BRAF may be involved in developing OA. BRAF regulated the downstream ERK signaling pathway. In addition, BRAF was upregulated in human OA cartilage as shown by immunohistochemistry. Remarkably, BRAF inhibition alleviated cartilage degradation in a mouse model of OA through its downstream of ERK pathway activation.

CONCLUSIONS

Jointly, these findings provide an overview of phosphoproteomic alterations occurring during cartilage degeneration, identifying the BRAF-ERK1/2 Axis signaling as a potential signaling pathway involved in OA.

Screening Clinical Changes for the Diagnosis of Early Knee Osteoarthritis: A Cross-Sectional Observational Study

Background: The main objective was to evaluate differences in the clinical, motor, or functional variables in patients with Early Osteoarthritis (EOA) and individuals at risk of developing osteoarthritis (OA). Methods: A cross-sectional study was performed. All the participants were divided into two groups: EOA patients and healthy subjects (HS) at risk of developing OA. The main outcomes were clinical tests, such as those of knee morphology, instability, or proprioception; motor and functional variables, such as knee strength, range of motion, walking speed, and the sit-to-stand test; pain and disability, assessed through the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC) and Knee injury and Osteoarthritis Outcome Score (KOOS) scales; and knee alignment and leg length inequality, assessed via X-ray images. Results: A total of 97 participants were included (54 EOA and 43 HS). Patients with EOA showed a greater presence of knee pain (p < 0.01). In addition, more EOA patients showed instability both in the left (p < 0.01) and right legs (p < 0.05). Regarding the knee alignment variable, significant differences were found (p < 0.04), with more patients with EOA diagnosed as possessing a varus alignment. In addition, EOA patients showed lower knee strength, since statistically significant differences were found regarding flexion and extension strength in the left leg (Mean Difference (MD): 12.92; p = 0.03; d = −0.46 and MD:7.81; p = 0.04; d = −0.39). Differences were found for the sit-to-stand test scores, showing lower results for the EOA group (MD: −1.91; p < 0.01; d = 0.54). Conclusions: The results of this research show statistically significant differences between patients with EOA and HS at risk of developing OA with respect to pain, disability, instability, knee strength, and the sit-to-stand test. Our results suggest that the evaluation of clinical, motor, and functional features could contribute to an early management of knee OA.

Runx2 and Runx3 differentially regulate articular chondrocytes during surgically induced osteoarthritis development

The Runt-related transcription factor (Runx) family plays various roles in the homeostasis of cartilage. Here, we examined the role of Runx2 and Runx3 for osteoarthritis development in vivo and in vitro. Runx3-knockout mice exhibited accelerated osteoarthritis following surgical induction, accompanied by decreased expression of lubricin and aggrecan. Meanwhile, Runx2 conditional knockout mice showed biphasic phenotypes: heterozygous knockout inhibited osteoarthritis and decreased matrix metallopeptidase 13 (Mmp13) expression, while homozygous knockout of Runx2 accelerated osteoarthritis and reduced type II collagen (Col2a1) expression. Comprehensive transcriptional analyses revealed lubricin and aggrecan as transcriptional target genes of Runx3, and indicated that Runx2 sustained Col2a1 expression through an intron 6 enhancer when Sox9 was decreased. Intra-articular administration of Runx3 adenovirus ameliorated development of surgically induced osteoarthritis. Runx3 protects adult articular cartilage through extracellular matrix protein production under normal conditions, while Runx2 exerts both catabolic and anabolic effects under the inflammatory condition.

Prediction Models to Estimate the Future Risk of Osteoarthritis in the General Population: A Systematic Review

OBJECTIVE

To evaluate the performance and applicability of multivariable prediction models for osteoarthritis (OA).

METHODS

This was a systematic review and narrative synthesis using 3 databases (EMBASE, PubMed, and Web of Science) from inception to December 2021. We included general population longitudinal studies reporting derivation, comparison, or validation of multivariable models to predict individual risk of OA incidence, defined by recognized clinical or imaging criteria. We excluded studies reporting prevalent OA and joint arthroplasty outcome. Paired reviewers independently performed article selection, data extraction, and risk-of-bias assessment. Model performance, calibration, and retained predictors were summarized.

RESULTS

A total of 26 studies were included, reporting 31 final multivariable prediction models for incident knee (23), hip (4), hand (3) and any-site OA (1), with a median of 121.5 (range 27-12,803) outcome events, a median prediction horizon of 8 years (range 2-41), and a median of 6 predictors (range 3-24). Age, body mass index, previous injury, and occupational exposures were among the most commonly included predictors. Model discrimination after validation was generally acceptable to excellent (area under the curve = 0.70-0.85). Either internal or external validation processes were used in most models, although the risk of bias was often judged to be high with limited applicability to mass application in diverse populations.

CONCLUSION

Despite growing interest in multivariable prediction models for incident OA, focus remains predominantly on the knee, with reliance on data from a small pool of appropriate cohort data sets, and concerns over general population applicability.

Measurement properties for muscle strength tests following anterior cruciate ligament and/or meniscus injury: What tests to use and where do we need to go? A systematic review with meta-analyses for the OPTIKNEE consensus

Objectives

Critically appraise and summarise the measurement properties of knee muscle strength tests after anterior cruciate ligament (ACL) and/or meniscus injury using the COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist.

Design

Systematic review with meta-analyses. The modified Grading of Recommendations Assessment, Development and Evaluation-guided assessment of evidence quality.

Data sources

Medline, Embase, CINAHL and SPORTSDiscus searched from inception to 5 May 2022.

Eligibility criteria for selecting studies

Studies evaluating knee extensor or flexor strength test reliability, measurement error, validity, responsiveness or interpretability in individuals with ACL and/or meniscus injuries with a mean injury age of ≤30 years.

Results

Thirty-six studies were included involving 31 different muscle strength tests (mode and equipment) in individuals following an ACL injury and/or an isolated meniscus injury. Strength tests were assessed for reliability (n=8), measurement error (n=7), construct validity (n=27) and criterion validity (n=7). Isokinetic concentric extensor and flexor strength tests were the best rated with sufficient intrarater reliability (very low evidence quality) and construct validity (moderate evidence quality). Isotonic extensor and flexor strength tests showed sufficient criterion validity, while isometric extensor strength tests had insufficient construct and criterion validity (high evidence quality).

Conclusion

Knee extensor and flexor strength tests of individuals with ACL and/or meniscus injury lack evidence supporting their measurement properties. There is an urgent need for high-quality studies on these measurement properties. Until then, isokinetic concentric strength tests are most recommended, with isotonic strength tests a good alternative.

The beneficial role of companion animals in translational pain research

The use of spontaneous painful disease in companion pet animals has been highlighted as one of the changes that could be made to help improve translation of basic science to new therapeutics, acting as a bridge between preclinical and clinical studies, with the goal of accelerating the approval of new therapeutics. This review focuses on the utility of companion pet dogs for translational research by reviewing what outcome measures can be measured, and importantly, the relevance of these outcome measures to human translational research. It also details the practical considerations involved in incorporating companion dogs into human therapeutic development.

Deep collaborative network with alpha matte for precise knee tissue segmentation from MRI

BACKGROUND AND OBJECTIVE

Precise segmentation of knee tissues from magnetic resonance imaging (MRI) is critical in quantitative imaging and diagnosis. Convolutional neural networks (CNNs), being state of the art, often challenged by the lack of image-specific adaptation, such as low tissue contrasts and structural inhomogeneities, thereby leading to incomplete segmentation results.

METHODS

This paper presents a deep learning-based automatic segmentation framework for precise knee tissue segmentation. A novel deep collaborative method is proposed, which consists of an encoder-decoder-based segmentation network in combination with a low rank tensor-reconstructed segmentation network. Low rank reconstruction in MRI tensor sub-blocks is introduced to exploit the morphological variations in knee tissues. To model the tissue boundary regions and effectively utilize the superimposed regions, trimap generation is proposed for defining high, medium and low confidence regions from the multipath CNNs. The secondary path with low rank reconstructed input mitigates the conditions in which the primary segmentation network can potentially fail and overlook the boundary regions. The outcome of the segmentation is solved as an alpha matting problem by blending the trimap with the source input.

RESULTS

Experiments on Osteoarthritis Initiative (OAI) datasets with all the 6 musculoskeletal tissues provide an overall segmentation dice score of 0.8925, where Femoral and Tibial part of cartilage achieving an average dice exceeding 0.9. The volumetric metrics also indicate the superior performances in all tissue compartments.

CONCLUSIONS

Experiments on Osteoarthritis Initiative (OAI) datasets and a self-prepared scan validate the effectiveness of the proposed method. Inclusion of extra prediction scale allowed the model to distinguish and segment the tissue boundary accurately. We specifically demonstrate the application of the proposed method in a cartilage segmentation-based thickness map for diagnosis purposes.

STRUCTURAL AND FUNCTIONAL CONDITION OF THE KNEE JOINT IN PATIENTS WITH MONOGONARTHROSIS IN THE STAGE OF EXACERBATION

The goal is to study the structural changes of the elements of the knee joint and their functional consequences in patients with monogonarthrosis of the 1st-2nd grade in the stage of exacerbation according to the data of a complex clinical and arthroscopic study. Materials and Methods. Materials - protocols of clinical, radiological and arthroscopic examination of 125 patients (54 (43.2%) men; 71 (57.8%) women), aged 18 - 79 years, with a previous diagnosis: Monoarthrosis of the knee joint in the stage of exacerbation. Research methods: questionnaire, orthopedic examination, X-ray diagnostics, arthroscopy, laboratory diagnostics of blood (determination of C-reactive protein (CRP) as a serological marker of inflammation), synovial fluid (analyses of physical properties, biochemical, cytological, bacteriological), statistical. Results and Discussion. According to the results of the comprehensive examination, the presence of primary monoarthrosis was confirmed in 118 (94.4%) patients (group A). Based on the definition of CRP, subgroups were distinguished: A1 (n=71; 56.8%) with a normal level and A2 (n=47; 37.6%) with elevated CRP. In 7 (5.6%) patients diagnosed seropositive unspecified rheumatoid monoarthritis with hypertrophic synovitis (group B). A significant predominance of women compared to men insubgroup A2 was revealed (p<0.05). It was investigated that the features of complaints, nature of pain sensations and indicators of orthopedic status in patients from subgroups A1 and A2 did not reliably differ in groups of patients with different levels of CRP. A significant predominance of normal contours of the affected knee joint was found in subgroups A1 (p<0.001) and A2 (p<0.01). Structural changes in knee joint elements according to X-ray and arthroscopic examination have no significant differences in subgroups of patients A1 and A2. Conclusions. The structural and functional state of the knee joints in patients with monogonarthrosis of the 1st-2nd grade according to the Kellgren-Lawrence classification is characterized by degenerative changes in almost all elements of the knee joint with moderate pain syndrome and functional disorders.

What tests should be used to assess functional performance in youth and young adults following anterior cruciate ligament or meniscal injury? A systematic review of measurement properties for the OPTIKNEE consensus

OBJECTIVES

To critically appraise and summarise measurement properties of functional performance tests in individuals following anterior cruciate ligament (ACL) or meniscal injury.

DESIGN

Systematic review.

DATA SOURCES

Systematic searches were performed in Medline (Ovid), Embase (Ovid), CINAHL (EBSCO) and SPORTSDiscus (EBSCO) on 7 July 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Studies evaluating at least one measurement property of a functional performance test including individuals following an ACL tear or meniscal injury with a mean injury age of ≤30 years. The COnsensus-based Standards for the selection of health Measurement INstruments Risk of Bias checklist was used to assess methodological quality. A modified Grading of Recommendations Assessment, Development and Evaluation assessed evidence quality.

RESULTS

Thirty studies evaluating 26 functional performance tests following ACL injury were included. No studies were found in individuals with an isolated meniscal injury. Included studies evaluated reliability (n=5), measurement error (n=3), construct validity (n=26), structural validity (n=1) and responsiveness (n=1). The Single Leg Hop and Crossover Hop tests showed sufficient intrarater reliability (high and moderate quality evidence, respectively), construct validity (low-quality and moderate-quality evidence, respectively) and responsiveness (low-quality evidence).

CONCLUSION

Frequently used functional performance tests for individuals with ACL or meniscal injury lack evidence supporting their measurement properties. The Single Leg Hop and Crossover Hop are currently the most promising tests following ACL injury. High-quality studies are required to facilitate stronger recommendations of performance-based outcomes following ACL or meniscal injury.

Imaging of Osteoarthritis of the Knee

Knee osteoarthritis is rising in prevalence, and more imaging studies are being requested to evaluate these patients. Although conventional radiographs of the knee are the most widely requested and available studies, other imaging modalities such as MRI, CT, and ultrasound may also be used. This article reviews commonly used imaging modalities, advantages and limitations of each, and their clinical applicability in diagnosing and monitoring knee osteoarthritis. New and advanced imaging techniques are also discussed as possible methods of early diagnosis and improved understanding of osteoarthritis pathophysiology.

Validating a Semi-Automated Technique for Segmenting Femoral Articular Cartilage on Ultrasound Images

OBJECTIVE

To validate a semi-automated technique to segment ultrasound-assessed femoral cartilage without compromising segmentation accuracy to a traditional manual segmentation technique in participants with an anterior cruciate ligament injury (ACL).

DESIGN

We recruited 27 participants with a primary unilateral ACL injury at a pre-operative clinic visit. One investigator performed a transverse suprapatellar ultrasound scan with the participant's ACL injured knee in maximum flexion. Three femoral cartilage ultrasound images were recorded. A single expert reader manually segmented the femoral cartilage cross-sectional area in each image. In addition, we created a semi-automatic program to segment the cartilage using a random walker-based method. We quantified the average cartilage thickness and echo-intensity for the manual and semi-automated segmentations. Intraclass correlation coefficients (ICC_2,k) and Bland-Altman plots were used to validate the semi-automated technique to the manual segmentation for assessing average cartilage thickness and echo-intensity. A dice correlation coefficient was used to quantify the overlap between the segmentations created with the semi-automated and manual techniques.

RESULTS

For average cartilage thickness, there was excellent reliability (ICC_2,k = 0.99) and a small mean difference (+0.8%) between the manual and semi-automated segmentations. For average echo-intensity, there was excellent reliability (ICC_2,k = 0.97) and a small mean difference (-2.5%) between the manual and semi-automated segmentations. The average dice correlation coefficient between the manual segmentation and semi-automated segmentation was 0.90, indicating high overlap between techniques.

CONCLUSIONS

Our novel semi-automated segmentation technique is a valid method that requires less technical expertise and time than manual segmentation in patients after ACL injury.

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).

Prevalence of Early Knee Osteoarthritis Illness Among Various Patient-Reported Classification Criteria After Anterior Cruciate Ligament Reconstruction

OBJECTIVE

To compare the prevalence of participants meeting different patient-reported criteria for early osteoarthritis (OA) illness after anterior cruciate ligament reconstruction (ACLR).

METHODS

Participants completed the Knee Injury and Osteoarthritis Outcomes Score (KOOS) at a single time point 5.0-7.9 months post-ACLR. We used established KOOS subscale criteria (i.e., Luyten original and Englund original) to define patient-reported early OA illness. A two-by-two contingency table and McNemar's test were used to compare the prevalence of participants who met the Luyten original versus Englund original KOOS criteria for early OA illness. These analyses were repeated using KOOS subscale thresholds based on established population-specific patient acceptable symptom state (PASS) within the Luyten and Englund KOOS criteria (i.e., Luyten PASS and Englund PASS).

RESULTS

A greater prevalence of participants with ACLR met the Luyten original criteria (n = 165 [54%]) compared to those who met the Englund original criteria (n = 128 [42%]; χ2  = 19.3, P < 0.001). When using the KOOS subscale PASS as thresholds, a significantly greater prevalence of participants with ACLR met the Luyten PASS criteria (n = 133 [43%]) compared to those who met the Englund PASS criteria (n = 85 [28%]; χ2  = 48.0, P < 0.001). When combining the Luyten and Englund KOOS criteria and using the original/PASS subscale thresholds, respectively, 40%/57% of participants met neither, 24%/15% met only 1, and 36%/28% met both KOOS criteria.

CONCLUSION

Regardless of the classification criteria used to define early OA illness, it is concerning that 28-54% of patients report considerable symptoms ~6 months post-ACLR. Our findings will improve the classification criteria to define early OA illness, which may raise awareness for the need of population-specific criteria.

Serum Cartilage Oligomeric Matrix Protein Detects Early Osteoarthritis in Patients With Anterior Cruciate Ligament Deficiency

PURPOSE

To investigate the ability of serum cartilage oligomeric matrix protein (COMP) to detect early osteoarthritis (OA) (International Cartilage Research Society [ICRS] grade 1 or 2 cartilage lesions) in patients with anterior cruciate ligament (ACL)-deficient patients.

METHODS

Patients with an ACL injury of Kellgren-Lawrence grade 0 or 1 were enrolled. Serum samples for COMP measurement were obtained before surgery. The cartilage surfaces of 6 compartments were classified using the ICRS grading system. The patients were divided into groups with and without early OA according to the cartilage findings and diagnostic criteria for early OA.

RESULTS

In total, 98 patients (mean age 23.7 years; range 12 to 49) were included, with 30 patients (30.6%) in the early OA group and 68 (69.4%) in the no early OA group. The 2 groups significantly differed in age, body mass index, preoperative Tegner activity scale, and serum COMP level. The cutoff value of serum COMP for the presence of early OA arthroscopic cartilage lesions was 152.0 ng/mL. Multiple logistic regression analysis revealed age (odds ratio 1.09; 95% confidence interval [CI] 1.02 to 1.16; P = .01) and serum COMP (odds ratio 1.02; 95% CI 1.01 to 1.04; P < .001) to be independent factors for the presence of early OA arthroscopic cartilage findings.

CONCLUSIONS

The incidence of early OA arthroscopic cartilage findings was ∼30% in patients with ACL deficiency, and serum COMP levels were significantly higher in the early OA group than in the no early OA group. The optimum cutoff value for serum COMP was 152 ng/mL. Serum COMP can be used to detect early cartilage change in patients with ACL deficiency.

LEVEL OF EVIDENCE

Ⅲ, retrospective comparative study.