Number of Persons With Symptomatic Knee Osteoarthritis in the US: Impact of Race and Ethnicity, Age, Sex, and Obesity

Budget impact of the Walk With Ease program for knee osteoarthritis

Objective

Walk With Ease (WWE) is an effective low-cost walking program. We estimated the budget impact of implementing WWE in persons with knee osteoarthritis (OA) as a measure of affordability that can inform payers' funding decisions.

Methods

We estimated changes in two-year healthcare costs with and without WWE. We used the Osteoarthritis Policy (OAPol) Model to estimate per-person medical expenditures. We estimated total and per-member-per-month (PMPM) costs of funding WWE for a hypothetical insurance plan with 75,000 members under two conditions: 1) all individuals aged 45+ with knee OA eligible for WWE, and 2) inactive and insufficiently active individuals aged 45+ with knee OA eligible. In sensitivity analyses, we varied WWE cost and efficacy and considered productivity costs.

Results

With eligibility unrestricted by activity level, implementing WWE results in an additional $1,002,408 to the insurance plan over two years ($0.56 PMPM). With eligibility restricted to inactive and insufficiently active individuals, funding WWE results in an additional $571,931 over two years ($0.32 PMPM). In sensitivity analyses, when per-person costs of $10 to $1000 were added with 10-50% decreases in failure rate (enhanced sustainability of WWE benefits), two-year budget impact varied from $242,684 to $6,985,674 with unrestricted eligibility and from -$43,194 (cost-saving) to $4,484,122 with restricted eligibility.

Conclusion

Along with the cost-effectiveness of WWE at widely accepted willingness-to-pay thresholds, these results can inform payers in deciding to fund WWE. In the absence of accepted thresholds to define affordability, these results can assist in comparing the affordability of WWE with other behavioral interventions.

Approaches to optimize analyses of multidimensional ordinal MRI data in osteoarthritis research: A perspective

Objective

Knee osteoarthritis (OA) is a disease of the whole joint involving multiple tissue types. MRI-based semi-quantitative (SQ) scoring of knee OA is a method to perform multi-tissue joint assessment and has been shown to be a valid and reliable way to measure structural multi-tissue involvement and progression of the disease. While recent work has described how SQ scoring may be used for clinical trial enrichment and disease phenotyping in OA, less guidance is available for how these parameters may be used to assess study outcomes.

Design

Here we present recommendations for summarizing disease progression within specific tissue types. We illustrate how various methods may be used to quantify longitudinal change using SQ scoring and review examples from the literature.

Results

Approaches to quantify longitudinal change across subregions include the count of number of subregions, delta-subregion, delta-sum, and maximum grade changes. Careful attention should be paid to features that may fluctuate, such as bone marrow lesions, or with certain interventions, for example pharmacologic interventions with anticipated cartilage anabolic effects. The statistical approach must align with the nature of the outcome.

Conclusions

SQ scoring presents a way to understand disease progression across the whole joint. As OA is increasingly recognized as a heterogeneous disease with different phenotypes a better understanding of longitudinal progression across tissue types may present an opportunity to match study outcome to patient phenotype or to treatment mechanism of action.

Causal relationship between periodontal disease-related phenotype and knee osteoarthritis: A two-sample mendelian randomization analysis

OBJECTIVE

This study aimed to explore the bidirectional causal relationship between periodontal disease-related phenotype (PDRP) and knee osteoarthritis (KOA) in a European population using a two-sample Mendelian Randomization (MR) approach.

METHODS

We leveraged publicly available GWAS summary statistics for PDRP (n = 975) and KOA (n = 403,124), assessing their roles as both exposures and outcomes. Our comprehensive MR analysis employed various methods, including inverse variance weighting (IVW), weighted median, Egger regression, simple mode, and weighted mode, to enhance the robustness of our findings. To ensure the reliability of our instrumental variables, we implemented a rigorous screening process based on p-values and F-values, utilized Phenoscanner to investigate potential confounders, and conducted sensitivity analyses.

RESULTS

Our analysis identified five SNPs associated with PDRP and three SNPs with KOA, all surpassing the genome-wide significance threshold, as instrumental variables. The IVW method demonstrated a significant causal relationship from PDRP to KOA (beta = 0.013, SE = 0.007, P = 0.035), without evidence of directional pleiotropy (MR-Egger regression intercept = 0.021, P = 0.706). No support was found for reverse causality from KOA to PDRP, as further MR analyses yielded non-significant P-values. Additionally, funnel plots and Cochran's Q test detected no significant heterogeneity or directional pleiotropy, confirming the robustness of our results. In multivariate analysis, when considering smoking, alcohol consumption, BMI collectively no direct causal relationship between KOA and PDRP. Conversely, smoking and higher BMI were independently associated with an increased risk of KOA.

CONCLUSION

In conclusion, our analysis revealed no direct causal relationship from KOA to PDRP. However, a causal relationship from PDRP to KOA was observed. Notably, when adjusting for potential confounders like smoking, alcohol intake, and BMI, both the causal connection from PDRP to KOA and the inverse relationship were not substantiated.

Association between omega-3 polyunsaturated fatty acids and osteoarthritis: results from the NHANES 2003-2016 and Mendelian randomization study

BACKGROUND

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs) exhibit potential as therapeutics for a variety of diseases. This observational and Mendelian randomization (MR) study aims to explore the relationship between omega-3 PUFAs and osteoarthritis (OA).

METHODS

Excluding individuals under 20 years old and those with missing data on relevant variables in the National Health and Nutrition Examination Survey (NHANES) spanning from 2003 to 2016, a total of 22 834 participants were included in this cross-sectional study. Weighted multivariable-adjusted logistic regression was used to estimate the association between omega-3 PUFAs and OA in adults. Moreover, restricted cubic splines were utilized to examine the dose-response relationship between omega-3 PUFAs and OA. To further investigate the potential causal relationship between omega-3 PUFAs and OA risk, a two-sample MR study was conducted. Furthermore, the robustness of the findings was assessed using various methods.

RESULTS

Omega-3 PUFAs intake were inversely associated with OA in adults aged 40 ∼ 59 after multivariable adjustment [Formula: see text], with a nonlinear relationship observed between omega-3 PUFAs intake and OA [Formula: see text]. The IVW results showed there was no evidence to suggest a causal relationship between omega-3 PUFAs and OA risk [Formula: see text].

CONCLUSIONS

Omega-3 PUFAs were inversely associated with OA in adults aged 40 ∼ 59. However, MR studies did not confirm a causal relationship between the two.

Impact of depressive symptoms on direct medical cost among medicare recipients with knee osteoarthritis

OBJECTIVE

Depressive symptoms are prevalent among knee osteoarthritis (KOA) patients and may lead to additional medical costs. We compared medical costs in Medicare Current Beneficiary Survey (MCBS) respondents with KOA with and without self-reported depressive symptoms.

METHODS

We identified a KOA cohort using ICD-9/10 diagnostic codes in both Part A and Part B claims among community-dwelling MCBS respondents from 2003 to 2019. We determined the presence of depressive symptoms using self-reported data on sadness or anhedonia. We considered three groups: 1) without depressive symptoms, 2) with depressive symptoms, no billable services, and 3) with depressive symptoms and billable services. We used a generalized linear model with log-transformed outcomes to compare annual total direct medical costs among the three groups, adjusting for age, gender, race, history of fall, Total Joint Replacement, comorbidities, and calendar year.

RESULTS

The analysis included 4118 MCBS respondents with KOA. Of them, 27% had self-reported depressive symptoms, and 6% reported depressive symptoms and received depression-related billable services. The adjusted mean direct medical costs were $8598/year for those without depressive symptoms, $9239/year for those who reported depressive symptoms and received no billable services, and $14,229/year for those who reported depressive symptoms and received billable services.

CONCLUSION

While over one quarter of Medicare beneficiaries with KOA self-reported depressive symptoms, only 6% received billable medical services. The presence of depressive symptoms led to higher direct medical costs, even among those who did not receive depression-related billable services.

Surgical restabilization reduces the progression of post-traumatic osteoarthritis initiated by ACL rupture in mice

OBJECTIVE

People who sustain joint injuries such as anterior cruciate ligament (ACL) rupture often develop post-traumatic osteoarthritis (PTOA). In human patients, ACL injuries are often treated with ACL reconstruction. However, it is still unclear how effective joint restabilization is for reducing the progression of PTOA. The goal of this study was to determine how surgical restabilization of a mouse knee joint following non-invasive ACL injury affects PTOA progression.

DESIGN

In this study, 187 mice were subjected to non-invasive ACL injury or no injury. After injury, mice underwent restabilization surgery, sham surgery, or no surgery. Mice were then euthanized on day 14 or day 49 after injury/surgery. Functional analyses were performed at multiple time points to assess voluntary movement, gait, and pain. Knees were analyzed ex vivo with micro-computed tomography, RT-PCR, and whole-joint histology to assess articular cartilage degeneration, synovitis, and osteophyte formation.

RESULTS

Both ACL injury and surgery resulted in loss of epiphyseal trabecular bone (-27-32%) and reduced voluntary movement at early time points. Joint restabilization successfully lowered OA score (-78% relative to injured at day 14, p < 0.0001), and synovitis scores (-37% relative to injured at day 14, p = 0.042), and diminished the formation of chondrophytes/osteophytes (-97% relative to injured at day 14, p < 0.001, -78% at day 49, p < 0.001).

CONCLUSIONS

This study confirmed that surgical knee restabilization was effective at reducing articular cartilage degeneration and diminishing chondrophyte/osteophyte formation after ACL injury in mice, suggesting that these processes are largely driven by joint instability in this mouse model. However, restabilization was not able to mitigate the early inflammatory response and the loss of epiphyseal trabecular bone, indicating that these processes are independent of joint instability.

Effect of weight loss on knee joint synovitis over 48 months and mediation by subcutaneous fat around the knee: data from the Osteoarthritis Initiative

BACKGROUND

Obesity influences the development of osteoarthritis via low-grade inflammation. Progression of local inflammation (= synovitis) increased with weight gain in overweight and obese women compared to stable weight. Synovitis could be associated with subcutaneous fat (SCF) around the knee. Purpose of the study was to investigate the effect of weight loss on synovitis progression and to assess whether SCF around the knee mediates the relationship between weight loss and synovitis progression.

METHODS

We included 234 overweight and obese participants (body mass index [BMI] ≥ 25 kg/m2) from the Osteoarthritis Initiative (OAI) with > 10% weight loss (n = 117) or stable overweight (< ± 3% change, n = 117) over 48 months matched for age and sex. In magnetic resonance imaging (MRI) at baseline and 48 months, effusion-synovitis and Hoffa-synovitis using the MRI Osteoarthritis Knee Score (MOAKS) and average joint-adjacent SCF (ajSCF) were assessed. Odds-ratios (ORs) for synovitis progression over 48 months (≥ 1 score increase) were calculated in logistic regression models adjusting for age, sex, baseline BMI, Physical Activity Scale for the Elderly (PASE), and baseline SCF measurements. Mediation of the effect of weight loss on synovitis progression by local SCF change was assessed.

RESULTS

Odds for effusion-synovitis progression decreased with weight loss and ajSCF decrease (odds ratio [OR] = 0.61 and 0.56 per standard deviation [SD] change, 95% confidence interval [CI] 0.44, 0.83 and 0.40, 0.79, p = 0.002 and 0.001, respectively), whereas odds for Hoffa-synovitis progression increased with weight loss and ajSCF decrease (OR = 1.47 and 1.48, CI 1.05, 2.04 and 1.02, 2.13, p = 0.024 and 0.038, respectively). AjSCF decrease mediated 39% of the effect of weight loss on effusion-synovitis progression.

CONCLUSIONS

Effusion-synovitis progression was slowed by weight loss and decrease in local subcutaneous fat. Hoffa-synovitis characterized by fluid in the infrapatellar fat pad increased at the same time, suggesting a decreasing fat pad rather than active synovitis. Decrease in local subcutaneous fat partially mediated the systemic effect of weight loss on synovitis.

Liquiritin reduces chondrocyte apoptosis through P53/PUMA signaling pathway to alleviate osteoarthritis

AIMS

The main pathological features of osteoarthritis (OA) include the degeneration of articular cartilage and a decrease in matrix synthesis. Chondrocytes, which contribute to matrix synthesis, play a crucial role in the development of OA. Liquiritin, an effective ingredient extracted from Glycyrrhiza uralensis Fisch., has been used for over 1000 years to treat OA. This study aims to investigate the impact of liquiritin on OA and its underlying mechanism.

MATERIALS AND METHODS

Gait and hot plate tests assessed mouse behavior, while Micro-CT and ABH/OG staining observed joint morphological changes. The TUNEL kit detected chondrocyte apoptosis. Western blot and immunofluorescence techniques determined the expression levels of cartilage metabolism markers COL2 and MMP13, as well as apoptosis markers caspase3, bcl2, P53, and PUMA. KEGG analysis and molecular docking technology were used to verify the relationship between liquiritin and P53.

KEY FINDINGS

Liquiritin alleviated pain sensitivity and improved gait impairment in OA mice. Additionally, we found that liquiritin could increase COL2 levels and decrease MMP13 levels both in vivo and in vitro. Importantly, liquiritin reduced chondrocyte apoptosis induced by OA, through decreased expression of caspase3 expression and increased expression of bcl2 expression. Molecular docking revealed a strong binding affinity between liquiritin and P53. Both in vivo and in vitro studies demonstrated that liquiritin suppressed the expression of P53 and PUMA in cartilage.

SIGNIFICANCE

This indicated that liquiritin may alleviate OA progression by inhibiting the P53/PUMA signaling pathway, suggesting that liquiritin is a potential strategy for the treatment of OA.

The dysregulated autophagy in osteoarthritis: Revisiting molecular profile

The risk factors of osteoarthritis (OA) are different and obesity, lifestyle, inflammation, cell death mechanisms and diabetes mellitus are among them. The changes in the biological mechanisms are considered as main regulators of OA pathogenesis. The dysregulation of autophagy is observed in different human diseases. During the pathogenesis of OA, the autophagy levels (induction or inhibition) change. The supportive and pro-survival function of autophagy can retard the progression of OA. The protective autophagy prevents the cartilage degeneration. Moreover, autophagy demonstrates interactions with cell death mechanisms and through inhibition of apoptosis and necroptosis, it improves OA. The non-coding RNA molecules can regulate autophagy and through direct and indirect control of autophagy, they dually delay/increase OA pathogenesis. The mitochondrial integrity can be regulated by autophagy to alleviate OA. Furthermore, therapeutic compounds, especially phytochemicals, stimulate protective autophagy in chondrocytes to prevent cell death. The protective autophagy has ability of reducing inflammation and oxidative damage, as two key players in the pathogenesis of OA.

Effectiveness of Yijinjing exercise in the treatment of early-stage knee osteoarthritis: a randomized controlled trial protocol

INTRODUCTION

Knee osteoarthritis (KOA) is still a challenging degenerative joint disease with high morbidity and disease burden. Early-stage KOA, the focus of this study, could present a Window of Opportunity to arrest the disease process and reduce the disease burden. Yijinjing exercise is an important part of physical and psychological therapies in Traditional Chinese Exercise and may be an effective treatment. However, there is no clinical efficacy assessment of Yijinjing exercise for patients with early-stage KOA. Therefore, we designed a randomised controlled trial to evaluate the effectiveness of Yijinjing exercise on patients with early-stage KOA.

METHODS AND ANALYSIS

This is a parallel-design, two-arm, analyst assessor-blinded, randomised controlled trial. In total, 60 patients with early-stage KOA will be recruited and randomly assigned to the Yijinjing exercise group (n=30) and health education group (n=30) at a ratio of 1:1, receiving 12 weeks of Yijinjing exercise or health education accordingly. The primary outcome will be measured with the Western Ontario and McMaster Universities Osteoarthritis Index, and the secondary outcomes will include the Visual Analogue Scale, Short-Form 36 Item Health Survey Questionnaire, Beck Depression Inventory, Perceived Stress Scale, Berg Balance Scale, and Gait Analysis for a comprehensive assessment. Outcome measures are collected at baseline, at 12 week ending intervention and at the 12 week, 24 week and 48 week ending follow-up. The primay time point will be 12 weeks postintervention. Adverse events will be recorded for safety assessment.

ETHICS AND DISSEMINATION

This study has been approved by the ethical application of the Shanghai Municipal Hospital of Traditional Chinese Medicine Ethics Committee (2021SHL-KY-78).

TRIAL REGISTRATION NUMBER

ChiCTR2200065178.

Association between nighttime sleep duration and quality with knee osteoarthritis in middle-aged and older Chinese: A longitudinal cohort study

BACKGROUND

The association between nighttime sleep duration and sleep quality with the risk of knee osteoarthritis (OA) remains unclear. This study aimed to examine the longitudinal association among middle-aged and older adults in China.

METHODS

The data used in this study were obtained from the China Health and Retirement Longitudinal Study (CHARLS) surveys conducted in 2011 and 2015. Nighttime sleep duration was categorized into five groups: <6 h, 6 to <7 h, 7 to <8 h, 8 to <9 h, and ≥9 h/night. Sleep quality was assessed by restless days in the past week (<1, 1-2, 3-4, and 5-7 days/week). Multivariate logistic regression models were used to assess the association between sleep duration and quality with incident knee OA.

RESULTS

A total of 11,114 participants who did not have knee OA at baseline were enrolled in this study. After 4 years of follow-up, the overall incidence of knee OA was 8.07 %. Compared to 7 to <8 h of sleep duration, short sleep duration (<6 h/night) was associated with a significantly increased risk of incident knee OA in the fully adjusted model [odds ratio (OR) =1.73, 95 % confidence interval (CI): 1.33-2.25]. Additionally, participants with 5-7 sleep restless days/week were associated with significantly increased risk of incident knee OA (OR = 1.88, 95 % CI: 1.48-2.38).

CONCLUSIONS

Short nighttime sleep duration and poor sleep quality are associated with increased risk of incident knee OA.

Bone Quality Assessment Before Total Hip Arthroplasty: The Role of Densitometry

Background Total hip arthroplasty (THA) is effective in the treatment of hip osteoarthritis. Radiographic evaluation, standard in THA planning, is sufficient in examining hip anatomy, although it may not precisely assess bone quality. A routinely implemented method in bone quality assessment is densitometry. The technique allows for a measurement of bone mineral density (BMD). Methodology In the study, we included 26 participants who qualified for THA. All the patients were preoperatively examined with radiographs and densitometry of the affected hip. On the preoperative anteroposterior radiograph, we measured the canal-to-calcar isthmus ratio (CC ratio) and the cortical index (CI). Intraoperatively, during the THA procedure, we measured the thickness of the cortical bone and the diameter of the femoral neck in the line of neck resection. Results The examination with Pearson's correlation coefficient revealed that BMD significantly positively correlates with the intraoperatively measured diameter of the femoral neck (r = 0.5, P = 0.009), and with the measured thickness of the cortical bone (r = 0.47, P = 0.015), CI significantly positively correlates with the intraoperatively measured diameter of the femoral neck (r = 0.6, P = 0.001), and with the CC ratio (r = 0.44, P = 0.024), the intraoperatively measured diameter of the femoral neck significantly positively correlates with the intraoperatively measured thickness of the cortical bone (r = 0.59, P = 0.001). All of the other correlations were not statistically significant. Conclusions BMD measurements can be used in THA planning as they positively correlate with intraoperative measurements. The radiological parameters (CC ratio and CI) may not be as precise in bone quality assessment.

Arthroscopy with partial meniscectomy for degenerative tear does not increase the risk of total knee arthroplasty at five year follow up; however, this population undergoes total knee arthroplasty with a lower threshold of osteoarthritis

PURPOSE

Degenerative meniscus tears can cause discomfort in some patients, and when medical treatments fail to provide relief, arthroscopy may be considered before resorting to knee prosthesis. However, the benefits of arthroscopy over nonsurgical treatments in patients over 60 years old are limited, and the evidence regarding its overall efficiency and drawbacks remains scarce. Furthermore, there has been no investigation into whether those patients treated with partial meniscectomy, undergo the knee operation at an earlier stage of osteoarthritis.

METHODS

This study focused on data from a single Belgian hospital, involving patients over 60 years old with internal meniscal tears. The participants were categorized into two groups based on the treatment they received: arthroscopic partial meniscectomy (APM) or conservative management. The primary outcome assessed was the occurrence of knee arthroplasty within a five year period. Secondary outcomes included evaluating the ICRS cartilage grade and the time taken until total knee arthroplasty (TKA).

RESULTS

A total of 194 patients with internal meniscal tears were included in the study. At the 5-year mark, the overall rate of knee arthroplasty was found to be 16.5%, with 11.9% of cases occurring within two years. After the 5-year follow-up, it was observed that 19.2% (24 patients) of the APM group and 11.6% (8 patients) of the conservative management group underwent knee arthroplasty. Notably, patients over 70 years old who underwent APM had a higher risk of eventually requiring TKA compared to those who received conservative management. Additionally, patients who underwent meniscectomy and later underwent TKA showed less wear in the internal compartment of the knee compared to patients in the conservative treatment group who underwent TKA.

CONCLUSION

The study suggests that patients who underwent arthroscopy faced a similar risk of knee arthroplasty compared to those who underwent conservative management, excepted for patients over 70 years old. Despite this similar risk of arthroplasty for the whole population, they exhibited lower osteoarthritis severity when compared to the conservative group.

Causal relationships between pain, medical treatments, and knee osteoarthritis: A graphical causal model to guide analyses

OBJECTIVE

Randomized controlled trials (RCTs) are a gold standard for estimating the benefits of clinical interventions, but their decision-making utility can be limited by relatively short follow-up time. Longer-term follow-up of RCT participants is essential to support treatment decisions. However, as time from randomization accrues, loss to follow-up and competing events can introduce biases and require covariate adjustment even for intention-to-treat effects. We describe a process for synthesizing expert knowledge and apply this to long-term follow-up of an RCT of treatments for meniscal tears in patients with knee osteoarthritis (OA).

METHODS

We identified 2 post-randomization events likely to impact accurate assessment of pain outcomes beyond 5 years in trial participants: loss to follow-up and total knee replacement (TKR). We conducted literature searches for covariates related to pain and TKR in individuals with knee OA and combined these with expert input. We synthesized the evidence into graphical models.

RESULTS

We identified 94 potential covariates potentially related to pain and/or TKR among individuals with knee OA. Of these, 46 were identified in the literature review and 48 by expert panelists. We determined that adjustment for 50 covariates may be required to estimate the long-term effects of knee OA treatments on pain.

CONCLUSION

We present a process for combining literature reviews with expert input to synthesize existing knowledge and improve covariate selection. We apply this process to the long-term follow-up of a randomized trial and show that expert input provides additional information not obtainable from literature reviews alone.

Finding the Goldilocks Zone of Mechanical Loading: A Comprehensive Review of Mechanical Loading in the Prevention and Treatment of Knee Osteoarthritis

In this review, we discuss the interaction of mechanical factors influencing knee osteoarthritis (KOA) and post-traumatic osteoarthritis (PTOA) pathogenesis. Emphasizing the importance of mechanotransduction within inflammatory responses, we discuss its capacity for being utilized and harnessed within the context of prevention and rehabilitation of osteoarthritis (OA). Additionally, we introduce a discussion on the Goldilocks zone, which describes the necessity of maintaining a balance of adequate, but not excessive mechanical loading to maintain proper knee joint health. Expanding beyond these, we synthesize findings from current literature that explore the biomechanical loading of various rehabilitation exercises, in hopes of aiding future recommendations for physicians managing KOA and PTOA and athletic training staff strategically planning athlete loads to mitigate the risk of joint injury. The integration of these concepts provides a multifactorial analysis of the contributing factors of KOA and PTOA, in order to spur further research and illuminate the potential of utilizing the body's own physiological responses to mechanical stimuli in the management of OA.

Increased Host Bone Marrow Edema on 6-Month MRI Is a Risk Factor for Osteochondral Allograft Failure

PURPOSE

To evaluate the presence of host bone marrow edema (BME) surrounding osteochondral allograft (OCA) plugs on routine 6-month postoperative magnetic resonance imaging (MRI) and to determine whether such BME is correlated with subsequent failure.

METHODS

The present study was approved under our institutional review board-approved database (#2020-2123). We included patients who underwent cartilage repair with OCA for focal chondral and osteochondral defects of the distal femur by 2 senior surgeons between January 2016 and May 2021 with minimum 2-year follow-up. OCA is frequently performed with concomitant procedures, and therefore ligament reconstruction, meniscal surgery, and osteotomy were not exclusion criteria. Failure was defined as (1) poor clinical outcome with graft collapse on follow-up MRI or second-look arthroscopy, (2) primary OCA removal or revision, or (3) conversion to unicompartmental or total knee arthroplasty. Routine MRI scans were performed at 6 ± 2 months postoperatively. All postoperative MRI scans were reviewed from our imaging record by 2 blinded fellowship-trained orthopaedic surgeons. Patients were divided for analyses into 2 groups: BME ≥10 cm3 versus BME <10 cm3.

RESULTS

Of the 85 patients eligible for the study, 56 patients (30 female, mean age 31.69 ± 11.34 years) had a minimum 2-year follow-up. Nonfailure cases had a mean clinical follow-up of 3.13 ± 0.93 years. The mean time from surgery to failure in our cohort was 1.67 ± 0.91 years. There were 12 (21.4%) patients with BME ≥10 cm³ and 44 (78.6%) patients with BME <10 cm³. No statistically significant differences were found between groups when compared for sex, age, body mass index, OCA size, time to MRI, mean follow-up, number of plugs, graft location, diagnosis, previous surgeries, or concomitant procedures. All OCA failures of the study cohort were in the BME ≥10 cm³ group, representing 50% of this group (P < .001). Kaplan-Meier survival analysis with the log-rank test demonstrated significant difference in survival distributions between groups (P < .001). Patients who ultimately failed had a mean BME volume of 18.49 ± 5.82 cm3, while the nonfailure group had a mean volume of 4.66 ± 4.97 cm3 (P < .001). Cutoff values around 10 cm³ in receiver operating characteristic curve analysis demonstrated 100% sensitivity and close to 90% specificity for OCA failure diagnosis.

CONCLUSION

Host BME with a volume greater than 10 cm³ on 6-month postoperative MRI is predictive of an increased subsequent failure rate after OCA transplantation with a failure rate of 50%.

LEVEL OF EVIDENCE

Level III, cohort study.

Evaluating the diagnostic accuracy of a screening tool for low physical activity in independently ambulating adults with knee osteoarthritis: A prospective cohort study

BACKGROUND AND PURPOSE

Patients with knee osteoarthritis (OA) can benefit from resistance training exercises, range of motion and flexibility maintenance, and low-load aerobic exercises, as per the relevant clinical guidelines. However, certain patients might be unable to progress to higher physical levels despite such physical therapy programs. This study aimed to evaluate the diagnostic accuracy of a screening tool for determining physical activity levels in individuals with OA undergoing standard physical therapy regularly, using likelihood ratios and predictive values.

METHOD

This prospective observational study included 135 patients undergoing standard physical therapy for OA from six medical facilities. The primary outcome was low physical activity or moderate to high physical activity levels based on 1-month Self-Rating Frenchay activities index scores. Backward elimination was used to perform binomial logistic regression analysis after identifying the independent variables in a univariate logistic regression analysis. Among the independent variables adopted in the logistic regression model, receiver operating characteristic analysis using Youden's index was performed for quantitative variables, which were converted to binary values at the cut-off points. Subsequently, the clinical prediction rule (CPR) was derived.

RESULTS

According to the binomial logistic regression analysis, age, knee flexion muscle strength, and visual analog scale (VAS) were risk factors for low physical activity, and the CPR was derived from these variables. The pre-test probability of the low physical activity group was 37.0% (50 out of 135 participants). For a total CPR score of three points (one point for each item: age ≤69 years, knee flexion muscle strength ≤0.36 Nm/kg, and VAS ≥33 mm), the positive likelihood ratio was 13.60 and the post-test probability increased to 88.9%.

DISCUSSION

The CPR identified patients who might not benefit from the standard physical therapy program. This screening tool could improve patient management, allowing for more tailored approaches in physical therapy programs.

Persistent altered knee loading in patients with meniscectomy: A systematic review and meta-analysis

OBJECTIVES

To determine the changes in knee flexion moment (KFM) and knee adduction moment (KAM) during weight-bearing activities following meniscectomy.

DESIGN

Meta-Analysis.

SETTING

Laboratory.

PARTICIPANTS

332 meniscectomy patients and 137 healthy controls (from 13 qualified studies) MAIN OUTCOME MEASURES: Cohen's d effect sizes (ESs) were calculated to compare KAM and KFM values of the surgical legs to the non-surgical and to healthy control legs.

RESULTS

When compared to healthy controls, meniscectomy patients' surgical legs demonstrated a significantly greater KAM (ES = 0.310; P = 0.002) but no significant difference in KFM (ES = -0.182; P = 0.051). When compared to the patients' non-surgical legs, however, the surgical legs showed no difference in KAM (ES = -0.024; P = 0.716) but a significantly lower KFM (ES = -0.422; P < 0.001). High heterogeneity among study ESs was observed in patients' between-limb comparison for KAM (Q-value = 20.08, P = 0.005; I2 = 65.1%) and KFM (Q-value = 43.96, P < 0.001; I2 = 79.5%). However, no significant differences in study ESs (all P > 0.102) of KFM and KAM were identified when comparing studies with various times post-surgery, weight-bearing tasks, walking speeds, or patient demographics.

CONCLUSION

Elevated KAM and reduced/asymmetrical KFM observed in meniscectomy patients may contribute to the increased risk of knee OA. Rehabilitation should focus on movement education to restore between-limb KFM symmetry and reduce KAM bilaterally post-meniscectomy.

Association Between Patient and Facility Characteristics and Rehabilitation Outcomes After Joint Replacement Surgery in Different Rehabilitation Settings for Older Adults: A Systematic Review

BACKGROUND AND PURPOSE

In the United States, an exponential increase in total hip arthroplasty (THA) and total knee arthroplasty (TKA) demand has occurred over the last 2 decades. Evidence suggesting patients receiving inpatient rehabilitation following a TKA or THA experience similar outcomes as those with rehabilitation in other settings led to dramatic shifts in postsurgical care settings owing to Centers for Medicare & Medicaid Services (CMS) payment reforms. A contemporary synthesis of evidence about the association between patient and facility factors and outcomes from older adults undergoing THA or TKA in the United States is needed.

METHODS

To identify eligible studies, we searched PubMed, Scopus, and CINAHL. We followed PRISMA guidelines to identify articles evaluating either patient or facility factors associated with outcomes after THA or TKA for older adults who may have been cared for in inpatient settings (ie, inpatient rehabilitation or skilled nursing facility [SNF]). Eligible articles were conducted in the United States and were published between January 1, 2000, and December 31, 2021.

RESULTS

We included 8 articles focused on patient factors and 9 focused on facility factors. Most included older adults and the majority were White (in those reporting race/ethnicity). Most studies evaluated outcomes at discharge and showed that patients admitted to inpatient rehabilitation facilities had either similar or better functional outcomes (mobility, self-care, and functional independence measure (FIM) score) and lower length of stay compared with those in SNFs. Few studies focused on home health care.

CONCLUSIONS

The systematic review focused on older adults showed that findings in these patients are consistent with previous research. Older adults undergoing THA/TKA had acceptable outcomes regardless of postsurgical, inpatient setting of care. Research conducted after CMS payment reforms, in home health care settings, and in more diverse samples is needed. Given the known racial/ethnic disparities in THA/TKA and the shifts to postsurgical home health care with little regulatory oversight of care quality, contemporary research on outcomes of postsurgical THA/TKA outcomes is warranted.

Arthroscopic Procedures Are Performed in 5% of Patients With Knee Osteoarthritis 1 Year Preceding Total Knee Arthroplasty and Are Associated With Increased Stiffness and Increased Costs

Purpose

To describe the different types of arthroscopic procedures that patients undergo in the year prior to total knee arthroplasty (TKA), reveal the cost associated with these procedures, and understand the relationship between preoperative arthroscopy and clinical outcomes after TKA.

Methods

An observational cohort study was conducted using the IBM Watson Health MarketScan databases. Patients with knee osteoarthritis who underwent unilateral isolated primary TKA between January 1, 2018, and September 30, 2019, were included. Knee arthroscopic procedures performed in the 1-year period before a primary TKA was identified. The primary outcomes of interest were cost of these procedures and the risk of 90-day postoperative complications.

Results

In total, 2,904 patients, representing 5.2% of the analyzed cohort, underwent arthroscopic procedures in the year prior to TKA. The most common procedure and diagnosis were meniscectomy and meniscal tear, respectively, with procedures performed an average of 7.2 ± 3.0 months before TKA. Average per patient costs were $9,716 ± $5,500 in the highest payment quartile vs $1,789 ± 636 in the lowest payment quartile. Patients with a history of arthroscopy were more likely to develop postoperative stiffness (P = .001), while no difference was found in the risk of 90-day periprosthetic joint infection (PJI).

Conclusions

Of the patients, 5.2% underwent knee arthroscopy in the year prior to TKA. While no association was seen with PJI risk, the costs associated with these procedures are high and may increase the overall cost of management of knee osteoarthritis.

Level of Evidence

Level III, retrospective comparative study.

Trends and risk factors for readmissions following press-fit total knee arthroplasty for the treatment of end-stage osteoarthritis of the knee: a five-year analysis

INTRODUCTION

The development of new prostheses with improved osseointegration, bone preservation, and reduced cost has renewed interest in uncemented total knee arthroplasty (UCTKA). In the current study, we aimed to: (1) assess demographic data of patients who were and were not readmitted and (2) identify patient-specific risk factors associated with readmission.

METHODS

A retrospective query from the PearlDiver database was performed from January 1, 2015, to October 31, 2020. International Classification of Disease, Ninth Revision (ICD-9), ICD-10, or Current Procedural Terminology (CPT) coding was used to distinguish cohorts of patients who had osteoarthritis of the knee and underwent UCTKA. Patients readmitted within 90 days were classified as the study population, while those who were not readmitted were classified as control. A linear regression model was utilized to analyze readmission risk factors.

RESULTS

The query yielded 14,575 patients, with 986 (6.8%) being readmitted. Patient demographics such as age (P < 0.0001), sex (P < 0.009), and comorbidity (P < 0.0001) were associated with annual 90-day readmission. Patient-specific risk factors associated with 90-day readmission following press-fit total knee arthroplasty were: arrhythmia (OR: 1.29, 95% CI: 1.11-1.49, P < 0.0005), coagulopathy (OR: 1.36, 95% CI: 1.13-1.63, P < 0.0007), fluid and electrolyte abnormalities (OR: 1.59, 95% CI: 1.38-1.84, P < 0.0001), iron deficiency anemia (OR: 1.49, 95% CI: 1.27-1.73, P < 0.0001), and obesity (OR: 1.37, 95% CI: 1.18-1.60, P < 0.0001).

DISCUSSION

This study demonstrates that patients with comorbidities, such as fluid and electrolyte problems, iron deficiency anemia, and obesity, were at an increased risk of readmission after having an uncemented total knee replacement. The risks of readmission following an uncemented total knee arthroplasty can be discussed with patients who have certain comorbidities by arthroplasty surgeons.

Intra-Articular Corticosteroid Injections Into a Preexisting Total Knee Arthroplasty are Associated With Increased Risk of Periprosthetic Joint Infection and Revision

Background

This study aims to determine the risks of periprosthetic joint infection (PJI) and revision associated with injecting a preexisting total knee arthroplasty (TKA) with intra-articular corticosteroids (IACSs).

Methods

The PearlDiver database was used to identify patients who underwent elective, primary TKA between 2015 and 2019. Patients who received IACS injections into the ipsilateral knee within 1 year after their primary TKA were matched 2:1 on age, gender, and Charlson comorbidity index and compared to a no-injection control group. The incidence of PJI at 1 year postoperatively and revision at 2 years postoperatively were compared between groups.

Results

A total of 27,059 patients were in the injection cohort and 54,116 patients in the control cohort. The overall PJI rate was 1.3% in the injection cohort and 0.8% in the control cohort (P < .001). The rate of PJI increased with the number of post-TKA IACS injections received: 1 injection (1.3%), 2 injections (1.4%), and >3 injections (1.8%) (P < .001 for all, compared to controls). The revision rate was 3.1% in the injection cohort and 1.3% in the control cohort (P < .001). Revision rates increased with the number of post-TKA IACS injections received: 1 injection (2.5%), 2 injections (4.2%), and >3 injections (7.3%) (P < .001 for all, compared to controls).

Conclusions

IACS injections into a preexisting TKA are associated with an incremental increased risk of prosthetic joint infection and revision. Considering the potential deleterious impact of PJI and complexity of revision procedures, IACS injections into a preexisting TKA should be strongly discouraged.

Nutritional Avocado Intervention Improves Physical Activity Measures in Hispanic/Latino Families: A Cluster RCT

Introduction

Nutrition and physical activity are key components for the prevention of cardiovascular disease. There remains a paucity of trial data on the effect of specific nutritional interventions on physical activity and sedentary time. One question is how a common nutrient-dense food such as avocado may impact physical activity and sedentary time in Hispanic/Latino families, a group that reports the lowest levels of physical activity.

Design

This is a 6-month clustered RCT.

Setting/participants

Seventy-two families (235 individuals) who identified as Hispanic/Latino were enrolled through the San Ysidro Health Center (San Diego, CA) between April 2017 and June 2018.

Intervention

After a 2-week run-in period, 35 families were randomized to the intervention arm (14 avocados/family/week), and 37 families were assigned to the control arm (3 avocados/family/week).

Main outcome measures

Linear mixed-effects models were used to assess changes in physical activity (MET minutes per week) between the groups during the 6-month trial. Secondary outcomes included sedentary time (minutes/week), BMI, and systolic and diastolic blood pressures.

Results

An adherence goal of >80% was achieved for both arms. Total mean physical activity increased by 2,197 MET minutes per week more in the intervention group (p<0.01) than in the control group, driven by between-group differences in moderate (p<0.01) versus vigorous (p=0.06) physical activity. After accounting for longitudinal repeated measures per participant and nested family effects, total adult physical activity remained significantly higher in the intervention than in the control group (+1,163 MET minutes per week on average per participant), with a significant intervention interaction term (p<0.01). There were no significant changes in sedentary time, BMI, or blood pressure.

Conclusions

Higher allocation of avocados was associated with significantly higher physical activity and no adverse changes in BMI or blood pressure, suggesting that this nutritional intervention may have beneficial pleiotropic effects.Trial registration: This study is registered at www.clinicaltrials.gov as NCT02903433.

Image-Guided Radiofrequency Ablation for Joint and Back Pain: Rationales, Techniques, and Results

Image-guided minimally invasive radiofrequency ablation (RFA) of sensory nerves has emerged as a treatment option for pain and swelling associated with advanced symptomatic joint and spine degeneration to bridge the gap between optimal medical therapy and surgical treatments. RFA of articular sensory nerves and the basivertebral nerve use image-guided percutaneous approaches resulting in faster recovery time and minimal risks. The current published evidence indicates clinical effectiveness; however, further research must be performed comparing other conservative treatments with RFA to understand further its role in different clinical settings, such as osteonecrosis. This review article discusses and illustrates the applications of RFA for treating symptomatic joint and spine degeneration.

The influence of meniscal pathology in the incidence of knee osteoarthritis: a review

IMPORTANCE

Knee osteoarthritis (OA) is a common cause of pain and disability in older persons, affecting approximately 14 million individuals in the USA. Meniscal damage is also common in this age group with a prevalence of 35% in a middle-aged and older community sample and 82% in persons with evidence of radiographic knee osteoarthritis. This paper systematically reviews evidence on the association of meniscal pathology and incident radiographic knee OA.

OBSERVATIONS

We included 15 articles, published between 2013 and 2021, assessing the relationship between meniscal pathology and OA incidence (Fig. 1). The menisci are crucial load-bearing structures, and the resulting increase in biomechanical stress due to meniscal damage increases the risk for OA development. While some discrepancies are present in the literature, a clinically meaningful association has been generally established between the presence of a meniscal tear or meniscal extrusion and subsequent development of incident OA. Of note, larger radial tears as well as complex and more severe tears exhibit the strongest association with the development of incident OA. The relationship between other features of meniscal morphology-such as meniscal volume and meniscal coverage-and incident OA is less clearly documented.

CONCLUSIONS AND RELEVANCE

The early detection of meniscal pathology can be used to trigger preventative and therapeutic strategies designed to avert or delay knee OA in this at-risk population.

Validation of a Low-Cost Portable Device for Inducing Noninvasive Anterior Cruciate Ligament Injury in Mice

Noninvasive compression-induced anterior cruciate ligament rupture (ACL-R) is an easy and reproducible model for studying post-traumatic osteoarthritis (PTOA) in mice. However, equipment typically used for ACL-R is expensive, immobile, and not available to all researchers. In this study, we compared PTOA progression in mice injured with a low-cost custom ACL-rupture device (CARD) to mice injured with a standard system (ElectroForce 3200). We quantified anterior-posterior (AP) joint laxity immediately following injury, epiphyseal trabecular bone microstructure, and osteophyte volume at 2 and 6 weeks post injury using micro-computed tomography, and osteoarthritis progression and synovitis at 2 and 6 weeks post injury using whole-joint histology. We observed no significant differences in outcomes in mice injured with the CARD system compared to mice injured with the Electroforce (ELF) system. However, AP joint laxity data and week 2 micro-CT and histology outcomes suggested that injuries may have been slightly more severe and PTOA progressed slightly faster in mice injured with the CARD system compared to the ELF system. Altogether, these data confirm that ACL-R can be successfully and reproducibly performed with the CARD system and that osteoarthritis (OA) progression is mostly comparable to that of mice injured with the ELF system, though potentially slightly faster. The CARD system is low cost and portable, and we are making the plans and instructions freely available to all interested investigators in the hopes that they will find this system useful for their studies of OA in mice.

Muti-factor analysis of sport activity level after high tibial osteotomy

BACKGROUND

Although many studies have shown that high tibial osteotomy is appropriate for active patients, there are limited multifactorial studies on patients' sport activity level after HTO in general population.

METHODS

158 patients who underwent HTO for knee osteoarthritis between January 2016 and December 2019 are included, with a 36-month follow-up. Information was collected from X-rays and questionnaire. The independent variables were age, sex, breadwinner (provide more than 50% income), sport activity level when the knee was pain-free before and after surgery, concomitant meniscal treatment history, Lysholm knee score, desire level for returning to sports. The 158 cases are divided into three groups according to their sports participation before and after operation, Chi-square tests and ANOVA analysis were adopted to identify the effect of these variables on sport activity level after HTO, and factors with statistical differences and clinical relevancies, or provided by previous research were assessed with the ordinal logistic regression analysis.

RESULTS

According to sport activity level analysis, 28(17.7%) patients were categorized into the sport level-reduced group, 97(61.4%) patients into the sport level-unchanged group, and 33(20.9%) patients into the sport level-improved group. Upon ordinal logistic regression analysis, postoperative MA%, age, BMI, and preoperative Lysholm knee score were statistically significant.

CONCLUSIONS

Higher postoperative MA%, younger age, lower BMI, and lower Lysholm score are associate with improvement on activity level after HTO. This finding provides valuable references in operation option and rehabilitation planning.

Group physical therapy for knee osteoarthritis: protocol for a hybrid type III effectiveness-implementation trial

BACKGROUND

Knee osteoarthritis (OA) is a leading cause of chronic pain and disability and one of the most common conditions treated in outpatient physical therapy (PT). Because of the high and growing prevalence of knee OA, there is a need for efficient approaches for delivering exercise-based PT to patients with knee OA. A prior randomized controlled trial (RCT) showed that a 6-session Group Physical Therapy Program for Knee OA (Group PT) yields equivalent or greater improvements in pain and functional outcomes compared with traditional individual PT, while requiring fewer clinician hours per patient to deliver. This manuscript describes the protocol for a hybrid type III effectiveness-implementation trial comparing two implementation packages to support delivery of Group PT.

METHODS

In this 12-month embedded trial, a minimum of 16 Veterans Affairs Medical Centers (VAMCs) will be randomized to receive one of two implementation support packages for their Group PT programs: a standard, low-touch support based on Replicating Effective Programs (REP) versus enhanced REP (enREP), which adds tailored, high-touch support if sites do not meet Group PT adoption and sustainment benchmarks at 6 and 9 months following launch. Implementation outcomes, including penetration (primary), adoption, and fidelity, will be assessed at 6 and 12 months (primary assessment time point). Additional analyses will include patient-level effectiveness outcomes (pain, function, satisfaction) and staffing and labor costs. A robust qualitative evaluation of site implementation context and experience, as well as site-led adaptations to the Group PT program, will be conducted.

DISCUSSION

To our knowledge, this study is the first to evaluate the impact of tailored, high-touch implementation support on implementation outcomes when compared to standardized, low-touch support for delivering a PT-based intervention. The Group PT program has strong potential to become a standard offering for PT, improving function and pain-related outcomes for patients with knee OA. Results will provide information regarding the effectiveness and value of this implementation approach and a deeper understanding of how healthcare systems can support wide-scale adoption of Group PT.

TRIAL REGISTRATION

This study was registered on March 7, 2022 at ClinicalTrials.gov (identifier NCT05282927 ).

Longitudinal Invariance Testing Of The Knee Injury Osteoarthritis Outcome Score For Joint Replacement Scale (KOOS-JR)

Background

The Knee Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) is a seven-item patient reported outcome measure used to assess perceived knee health. Though commonly used, the longitudinal psychometric properties of the KOOS-JR have not been established and further characterization of its structural validity and multi-group invariance properties is warranted.

Purpose

The purpose of this study was to evaluate psychometric properties of the KOOS-JR in a large sample of patients who received care for knee pathology.

Study Design

Original research.

Methods

Longitudinal data extracted from the Surgical Outcome System (SOS) database of 13,470 knee pathology patients who completed the KOOS-JR at baseline, three-months, six- months, and one-year. Scale structure was assessed with confirmatory factor analysis (CFA), while multi-group and longitudinal invariance properties were assessed with CFA-based procedures. Latent group means were compared with statistical significance set at α ≤ .05 and Cohen's d effect size as d = 0.2 (small), d = 0.5 (medium), and d = 0.8 (large).

Results

CFA results exceeded goodness-of-fit indices at all timepoints. Multi-group invariance properties passed test requirements. Longitudinal analysis identified a biased item resulting in removal of item #1; the retained six-item model (KOOS-JR-6) passed longitudinal invariance requirements. KOOS-JR-6 scores significantly changed over time (p ≤ .001, Mdiff = 1.08, Cohen's d = 0.57): the highest scores were at baseline examination and the lowest at 12-month assessment.

Conclusions

The KOOS-JR can be used to assess baseline differences between males and females, middle and older aged adults, and patients receiving total knee arthroplasty or non-operative care. Caution is warranted if the KOOS-JR is used longitudinally due to potential measurement error associated with item #1. The KOOS-JR-6 may be a more viable option to assess change over time; however, more research is warranted.

Level of Evidence

3© The Author(s).

Corticosteroid Injections for Symptomatic Treatment of Osteoarthritis of the Knee: A Pilot Blinded Randomized Trial

OBJECTIVE

To quantify the effect of corticosteroids compared to lidocaine-only injections over 12 weeks among patients with knee osteoarthritis (KOA).

METHODS

Participants with KOA were randomized to receive a knee injection of methylprednisolone acetate 1 mL (40 mg) plus 2 mL lidocaine (1%) or 1 mL saline and 2 mL lidocaine. Participants and providers were blinded to treatment allocation using an opacified syringe. The outcome was the average change from baseline of the total Knee Injury and Osteoarthritis Outcome Score (KOOS) (range 0-100) assessed at 2-week intervals over 12 weeks. Participants received KOOS questionnaires on their smartphones through a web-based platform. We used linear mixed-effects regressions with robust variance estimators to evaluate the association between the intervention and change in KOOS total and subscales (ClinicalTrials.gov identifier NCT03835910; registered 2019-02-11).

RESULTS

Of the 33 randomized participants, 31 were included in the final analysis. The predicted mean (SE) change in total KOOS over the 12-week follow-up was 9.4 (3.2) in the corticosteroids arm versus -1.3 (1.4) in the control arm (P = 0.003). Of participants, 47% achieved change as large as the minimal clinically important difference (16 units) in the intervention arm compared to 6% of participants in the lidocaine arm. Further, there were greater improvements in the intervention arm for KOOS subscales and for Patient Reported Outcomes Measurement Information System (PROMIS) assessments of pain intensity, behavior, and interference.

CONCLUSION

Corticosteroid injections demonstrated clinically meaningful improvements in KOA symptoms over 12 weeks of follow-up. These data support larger studies to better quantify short-term benefits.

Non-Invasive Compression-Induced Anterior Cruciate Ligament (ACL) Injury and In Vivo Imaging of Protease Activity in Mice

Traumatic joint injuries such as anterior cruciate ligament (ACL) rupture or meniscus tears commonly lead to post-traumatic osteoarthritis (PTOA) within 10-20 years following injury. Understanding the early biological processes initiated by joint injuries (e.g., inflammation, matrix metalloproteinases (MMPs), cathepsin proteases, bone resorption) is crucial for understanding the etiology of PTOA. However, there are few options for in vivo measurement of these biological processes, and the early biological responses may be confounded if invasive surgical techniques or injections are used to initiate OA. In our studies of PTOA, we have used commercially available near-infrared protease activatable probes combined with fluorescence reflectance imaging (FRI) to quantify protease activity in vivo following non-invasive compression-induced ACL injury in mice. This non-invasive ACL injury method closely recapitulates clinically relevant injury conditions and is completely aseptic since it does not involve disrupting the skin or the joint capsule. The combination of these injury and imaging methods allows us to study the time course of protease activity at multiple time points following a traumatic joint injury.

Leptin and interleukin-1β levels associated with osteoarthritis in Vietnamese patients: a cross-sectional analysis

Leptin and interleukin-1 beta (IL-1β) are two extensively studied biomarkers associated with metabolic syndrome (MetS) and osteoarthritis (OA). Previous studies have mostly focused on either MetS or OA alone, with no available data on Vietnamese patients. This study aimed to investigate the levels of leptin and IL-1β in this patient population and explore their association with clinical parameters of MetS and OA. The study included 164 patients with primary knee OA, who were classified into two categories based on the presence of MetS, and 78 healthy controls. The plasma leptin and IL-1β levels were quantified by ELISA and correlated with clinical parameters. Leptin levels were higher in patients with OA (11.50±10.04 ng/mL) than in healthy controls (0.54±0.37 ng/mL) and increased in patients with MetS compared to those without MetS. IL-1β levels were also significantly higher in OA patients (14.63±15.87 pg/mL) than in controls (7.79±5.11 pg/mL), but were not significantly different between the MetS and non-MetS groups. Leptin levels were positively correlated with body mass index, waist-to-hip ratio, visual analogue scale scores, HbA1c and insulin levels, and HOMA-IR index, whereas IL-1β levels were only correlated with insulin levels and HOMA-IR index. ROC curve analysis revealed that leptin and IL-1β levels could distinguish individuals with and without OA (AUC=0.96; 0.88, respectively), and individuals with and without MetS (AUC=0.82; 0.71, respectively). Our findings suggested that both leptin and IL-1β levels were associated with both MetS and OA and may play a critical role in the pathogenesis of MetS-related OA.

Comparison of evaluation metrics of deep learning for imbalanced imaging data in osteoarthritis studies

PURPOSE

To compare the evaluation metrics for deep learning methods that were developed using imbalanced imaging data in osteoarthritis studies.

MATERIALS AND METHODS

This retrospective study utilized 2996 sagittal intermediate-weighted fat-suppressed knee MRIs with MRI Osteoarthritis Knee Score readings from 2467 participants in the Osteoarthritis Initiative study. We obtained probabilities of the presence of bone marrow lesions (BMLs) from MRIs in the testing dataset at the sub-region (15 sub-regions), compartment, and whole-knee levels based on the trained deep learning models. We compared different evaluation metrics (e.g., receiver operating characteristic (ROC) and precision-recall (PR) curves) in the testing dataset with various class ratios (presence of BMLs vs. absence of BMLs) at these three data levels to assess the model's performance.

RESULTS

In a subregion with an extremely high imbalance ratio, the model achieved a ROC-AUC of 0.84, a PR-AUC of 0.10, a sensitivity of 0, and a specificity of 1.

CONCLUSION

The commonly used ROC curve is not sufficiently informative, especially in the case of imbalanced data. We provide the following practical suggestions based on our data analysis: 1) ROC-AUC is recommended for balanced data, 2) PR-AUC should be used for moderately imbalanced data (i.e., when the proportion of the minor class is above 5% and less than 50%), and 3) for severely imbalanced data (i.e., when the proportion of the minor class is below 5%), it is not practical to apply a deep learning model, even with the application of techniques addressing imbalanced data issues.

Autologous micro-fragmented adipose tissue in the treatment of atherosclerosis patients with knee osteoarthritis in geriatric population: A systematic review and meta-analysis

BACKGROUND

Atherosclerosis and osteoarthritis are closely related. However, no high-quality studies have investigated the potential of micro-fragmented adipose tissue to treat patients with atherosclerosis accompanied by osteoarthritis.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Infrastructure, WANFANG DATA, and CQVIP were searched for potentially eligible studies published before October 13, 2022. Due to the statistical limitations of the existing relevant literature, it is not possible to make direct statistics on the patients with osteoarthritis accompanied by atherosclerosis treated by micro-fragmented adipose tissue. The primary outcome consisted of two parts: 1) Correlation between atherosclerosis and osteoarthritis; 2) Scores of the Knee injury and Osteoarthritis Outcome Score (KOOS). And secondary outcomes were pain assessed by visual analog scale (VAS) or numeric rating scale (NRS), quality of life (QoL) (assessed using tools apart from the KOOS), and adverse events (AEs). Random meta-analysis was conducted using STATA 14.0.

RESULTS

Nineteen studies were included. The metaanalysis evidenced a positive association between atherosclerosis and osteoarthritis (OR 1.17, CI 1.01-1.36). The mean absolute difference in KOOS subscale scores between pre- and post-treatment (mean with 95% confidence interval [CI]) was 19.65 (13.66, 25.63), 14.20 (4.64, 23.76), 19.95 (13.02, 26.89), 25.23 (14.80, 35.66), and 26.01 (13.68, 38.35) for pain, symptoms, activities of daily living (ADL), sports/recreation, and quality-of-life (QOL), respectively. The mean differences in VAS, resting VAS, activity VAS, and NRS between pre- and post-treatment was -8.24 (-10.66, -5.82), -3.61 (-4.49, -2.72), -4.17 (-4.89, -3.44), and -2.17 (-4.06, and -0.28), respectively. The mean difference in score of Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EQ-5D, and University of California in Los Angeles (UCLA) between pre- and post-treatment was -24.81 (-40.80, -8.82), 0.07 (0.02, 0.12), and 0.30 (-0.42, 1.02), respectively. The mean difference in Tegner score and the International Knee Documentation Committee (IKDC) score between pre- and post-treatment was 0.67 (-0.62, 1.97) and 13.70 (6.35, 21.04), respectively. The use of micro-fragmented adipose tissue was associated with risk of bruising, bleeding, hematoma, drainage, infection, soreness, swelling, pain, and stiffness in harvest and injection sites.

CONCLUSION

Atherosclerosis and osteoarthritis share common risk factors and comorbidity. And the use of micro-fragmented adipose tissue may benefit for improving symptoms of knee osteoarthritis accompanied by atherosclerosis although may lead to some mild adverse events. Randomized controlled trials with long-term follow-up are necessary for further evaluation because many limitations of this meta-analysis cannot be ignored.

A comparison of jade moxibustion and traditional moxibustion in the treatment of knee osteoarthritis: A randomized clinical trial

BACKGROUND

This study was developed to compare the relative clinical efficacy of traditional moxibustion and Jade moxibustion in an effort to define the most effective approaches to treating knee osteoarthritis.

METHODS

In total, 94 patients were randomly assigned at a 1:1 ratio to the traditional moxibustion (TM) and Jade moxibustion (JM) groups. For JM, a jade kneepad was preheated for 3 minutes via electrification, with the jade in the kneepad being pressed onto acupoints when reaching an initial temperature of 46°C. For patients in the TM group, moxa cones were applied to acupoints for treatment. In total, 12 treatments were performed for patients in each group, with treatment being conducted 3 times per week. Study outcomes included 36-item short-form health survey and Western Ontario and McMaster Universities Osteoarthritis Index knee stiffness scores. In addition, serum levels of osteoarthritis-related cytokines were measured.

RESULTS

Overall, 89/94 patients completed this study, including 44 and 45 in the TM and JM groups, respectively. The 36-item short-form health survey physical functioning at weeks 12 and 24 (P = .033, 0.001), role-physical at weeks 4 and 24 (P = .030, 0.014), and role-emotional at week 4 (P = .045) were the only scores to differ significantly between the TM and JM groups. Western Ontario and McMaster Universities Osteoarthritis Index stiffness scores in the JM groups improved significantly relative to baseline at weeks 4, 8, 12, and 24 (all P < .01). The scores in the TM group differed significantly at all time points relative to baseline (all P < .01), with no differences between groups (all P > .05). Serum Interleukin-2 levels were lower in both groups (all P < .01). Cartilage oligomeric matrix protein and monocyte chemotactic protein-1 only differed significantly for patients treated via JM (P < .05, P < .01), with the same also being true for Interleukin-1β and Interleukin-8 in the TM group (all P < .01). No significant differences in other cytokines were observed, nor did they differ significantly between groups (all P > .05).

CONCLUSION

These results suggest that JM treatment can improve knee osteoarthritis patient quality of life, alleviating joint stiffness and restoring joint function with a level of efficacy comparable to TM.

Review of genicular artery embolization, radiofrequency ablation, and cryoneurolysis in the management of osteoarthritis-related knee pain

Osteoarthritis (OA) of the knee represents one of the most common diseases in the world, affecting an estimated 14 million people in the United States alone. Exercise therapy and oral pain medication are first-line treatments but have limited efficacy. Next-line treatments such as intra-articular injections are limited in durability. Moreover, total knee replacements, although effective, require surgical intervention, which has considerable variability in patient satisfaction. Novel minimally invasive image-guided interventions are becoming more widespread for treating OA-related knee pain. Recent studies of these interventions have revealed promising results, minor complications, and reasonable patient satisfaction. In this study, published manuscripts were reviewed in the field of minimally invasive, image-guided interventions for OA-related knee pain, with a focus on genicular artery embolization, radiofrequency ablation, and cryoneurolysis. Recent studies have demonstrated a significant decrease in pain-related symptoms following these interventions. Reported complications were mild in the reviewed studies. Image-guided interventions for OA-related knee pain exist as valuable options for patients who fail other therapies, may not be good surgical candidates, or wish to avoid surgical intervention. Further studies with randomization and an increased length of follow-up are needed to better characterize outcomes following these minimally invasive therapies.

The molecular link between obstructive sleep apnea and osteoarthritis: based on bioinformatics analysis and experimental validation

BACKGROUND

Obstructive sleep apnea (OSA) and osteoarthritis (OA) are highly prevalent and seriously affect the patient's quality of life. Patients with OSA have a high incidence of OA, however, the underlying mechanism remains unclear. Here, we investigated the molecular link between OSA and OA via bioinformatics analysis and experimental validation.

METHODS

We downloaded a peripheral blood monocyte microarray profile (GSE75097) for patients with OSA and two synovial microarray profiles (GSE55235 and GSE55457) for patients with OA from the Gene Expression Omnibus database. We identified OSA-associated differentially expressed genes (OSA-DEGs) in patients with OA. Additionally, we constructed protein-protein interaction networks to identify the key genes involved in OA. Immunohistochemistry was performed to verify the expression of key genes in OA rat models. RNA interference assay was performed to validate the effects of key genes on synovial cells. Gene-miRNA, gene-transcription factor, and gene-drug networks were constructed to predict the regulatory molecules and drugs for OA.

RESULTS

Fifteen OSA-DEGs screened using the threshold criteria were enriched in the tumor necrosis factor (TNF) pathway. Combining the 12 algorithms of CytoHubba, we identified JUNB, JUN, dual specificity phosphatase 1 (DUSP1), and TNF-alpha-induced protein 3 (TNFAIP3) as the key OSA-DEGs involved in OA development. Immunohistochemistry and quantitative polymerase chain reaction revealed that these key genes were downregulated in the OA synovium, promoting TNF-α expression. Therefore, OSA-DEGs, JUN, JUNB, DUSP1, and TNFAIP3 function in OA by increasing TNF-α expression. Our findings provide insights on the mechanisms underlying the effects of OSA on OA.

Adaptation of the WOMAC for Use in a Patient Preference Study

OBJECTIVES

To adapt a patient-reported outcome (PRO) measure, the Western Ontario McMaster Universities Osteoarthritis Index (WOMAC), into efficacy attributes for a discrete choice experiment (DCE) survey designed to quantify the relative importance of endpoints commonly used in knee osteoarthritis (KOA) trials.

METHODS

The adaptation comprised four steps: (1) selecting domains of interest; (2) determining presentation and framing of selected attributes; (3) determining attribute levels; and (4) developing choice tasks. This process involved input from multiple stakeholders, including regulators, health preference researchers, and patients. Pretesting was conducted to evaluate if patients comprehended the adapted survey attributes and could make trade-offs among them.

RESULTS

The WOMAC pain and function domains were selected for adaption to two efficacy attributes. Two versions of the discrete choice experiment (DCE) instrument were created to compare efficacy using (1) total domain scores and (2) item scores for "walking on a flat surface." Both attributes were presented as improvement from baseline scores by levels of 0%, 30%, 50%, and 100%. Twenty-six participants were interviewed in a pretest of the instrument (average age 60 years; 58% female; 62% had KOA for ≥ 5 years). The participants found both versions of attributes meaningful and relevant for treatment decision-making. They demonstrated willingness and ability to tradeoff improvements in pain and function separately, though many perceived them as inter-related.

CONCLUSIONS

This study adds to the growing literature regarding adapting PRO measures for patient preference studies. Such adaptation is important for designing a preference study that can incorporate a clinical trial's outcomes with PRO endpoints.

Effects of Leptin and Body Weight on Inflammation and Knee Osteoarthritis Phenotypes in Female Rats

Leptin is a proinflammatory adipokine that contributes to obesity-associated osteoarthritis (OA), especially in women. However, the extent to which leptin causes knee OA separate from the effect of increased body weight is not clear. We hypothesized that leptin is necessary to induce knee OA in obese female rats but not sufficient to induce knee OA in lean rats lacking systemic metabolic inflammation. The effect of obesity without leptin signaling was modeled by comparing female lean Zucker rats to pair fed obese Zucker rats, which possess mutant fa alleles of the leptin receptor gene. The effect of leptin without obesity was modeled in female F344BN F1 hybrid rats by systemically administering recombinant rat leptin versus saline for 23 weeks via osmotic pumps. Primary OA outcomes included cartilage histopathology and subchondral bone micro-computed tomography. Secondary outcomes included targeted cartilage proteomics, serum inflammation, and synovial fluid inflammation following an acute intra-articular challenge with interleukin-1β (IL-1β). Compared to lean Zucker rats, obese Zucker rats developed more severe tibial osteophytes and focal cartilage lesions in the medial tibial plateau, with modest changes in proximal tibial epiphysis trabecular bone structure. In contrast, exogenous leptin treatment, which increased plasma leptin sixfold without altering body weight, caused mild generalized cartilage fibrillation and reduced Safranin O staining compared to vehicle-treated animals. Leptin also significantly increased subchondral and trabecular bone volume and bone mineral density in the proximal tibia. Cartilage metabolic and antioxidant enzyme protein levels were substantially elevated with leptin deficiency and minimally suppressed with leptin treatment. In contrast, leptin treatment induced greater changes in systemic and local inflammatory mediators compared to leptin receptor deficiency, including reduced serum IL-6 and increased synovial fluid IL-1β. In conclusion, rat models that separately elevate leptin or body weight develop distinct OA-associated phenotypes, revealing how obesity increases OA pathology through both leptin-dependent and independent pathways. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Improved genetic prediction of the risk of knee osteoarthritis using the risk factor-based polygenic score

BACKGROUND

Polygenic risk score (PRS) analysis is used to predict disease risk. Although PRS has been shown to have great potential in improving clinical care, PRS accuracy assessment has been mainly focused on European ancestry. This study aimed to develop an accurate genetic risk score for knee osteoarthritis (OA) using a multi-population PRS and leveraging a multi-trait PRS in the Japanese population.

METHODS

We calculated PRS using PRS-CS-auto, derived from genome-wide association study (GWAS) summary statistics for knee OA in the Japanese population (same ancestry) and multi-population. We further identified risk factor traits for which PRS could predict knee OA and subsequently developed an integrated PRS based on multi-trait analysis of GWAS (MTAG), including genetically correlated risk traits. PRS performance was evaluated in participants of the Nagahama cohort study who underwent radiographic evaluation of the knees (n = 3,279). PRSs were incorporated into knee OA integrated risk models along with clinical risk factors.

RESULTS

A total of 2,852 genotyped individuals were included in the PRS analysis. The PRS based on Japanese knee OA GWAS was not associated with knee OA (p = 0.228). In contrast, PRS based on multi-population knee OA GWAS showed a significant association with knee OA (p = 6.7 × 10^-5, odds ratio (OR) per standard deviation = 1.19), whereas PRS based on MTAG of multi-population knee OA, along with risk factor traits such as body mass index GWAS, displayed an even stronger association with knee OA (p = 5.4 × 10^-7, OR = 1.24). Incorporating this PRS into traditional risk factors improved the predictive ability of knee OA (area under the curve, 74.4% to 74.7%; p = 0.029).

CONCLUSIONS

This study showed that multi-trait PRS based on MTAG, combined with traditional risk factors, and using large sample size multi-population GWAS, significantly improved predictive accuracy for knee OA in the Japanese population, even when the sample size of GWAS of the same ancestry was small. To the best of our knowledge, this is the first study to show a statistically significant association between the PRS and knee OA in a non-European population.

TRIAL REGISTRATION

No. C278.

Bibliometric Analysis of Publications in Clinical Trials on Knee Osteoarthritis Between 2001 and 2022

Purpose

Clinical treatment of knee osteoarthritis has gained great interest, and numerous clinical studies have been reported. Few studies have described the detailed characterizations of clinical trials on knee osteoarthritis. This study is to identify, visualize, and characterize the clinical trials in knee osteoarthritis research.

Design and Methods

Articles published in recent two decades were extracted from the Web of Science core collection database using a query based on MeSH terms and topics of knee osteoarthritis and clinical trial. Basic characteristics of publications were analyzed based on the publication year, authors, institutions, counties, and keywords covered in the article. CiteSpace and VOS viewer were used for data visualization. The data were retrieved on May 28, 2022.

Results

A total of 1972 trials on knee osteoarthritis were identified. The number of publications has experienced rapid growth in the past two decades. America, England, and China had strong contributions in publication. Osteoarthritis and Cartilage, Annals of the Rheumatic Diseases and American Journal of Sports Medicine were highly cited and bellwether journals. Clustering mapping of the collaborative network, co-citation, and co-occurrence analyses showed that the research hotspots are mainly focused on disease-modifying medications, intra-articular injections, physical therapy for symptom control, lifestyle intervention, Chinese medicine treatment, and knee replacement.

Conclusion

Clinical treatments of knee OA are evolving. Pharmacologic therapy, intra-articular therapy, nonpharmacologic therapy including exercise or diet, self-management programs, Chinese medicine treatment, and knee replacement were highly represented in clinical trials of knee OA. Adjustment of combination therapy may be the next study focus in the future.

Effects of platelet-rich plasma on subchondral bone marrow edema and biomarkers in synovial fluid of knee osteoarthritis

BACKGROUND

The aim of the study was to investigate the effect of platelet-rich plasma (PRP) on subchondral bone marrow edema (BME) and the level of biomarkers in synovial fluid of the knee osteoarthritis.

METHODS

Eighty-one patients with symptomatic knee osteoarthritis were randomly divided into two groups according to the number of inpatients. Forty-five cases were treated with intra-articular injection of PRP (PRP group), 36 cases were treated with sodium hyaluronate (SH group), and the clinical effects were evaluated using the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. The changes of subchondral BME were assessed by magnetic resonance imaging (MRI) before and after treatment. The levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in synovial fluid were also detected.

RESULTS

All the patients completed the corresponding treatment and were followed up for 12 months without serious complications. After the treatment, the VAS and WOMAC scores of the two groups were significantly decreased, and the difference was statistically significant at different time points (P < 0.05). The VAS and WOMAC scores of the PRP group were better than those of the SH group (P < 0.05). MRI showed that the subchondral bone edema of the two groups were reduced in varying degrees, and the reduction was more noticeable in the PRP group (P < 0.05). The levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in two groups were decreased, and the difference was statistically significant at different time points (P < 0.05). However, the levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in the PRP group were significantly lower than those in the SH group (P < 0.05).

CONCLUSIONS

Intra-articular injection of PRP can significantly reduce the subchondral BME and the level of biomarkers in synovial fluid of the symptomatic knee osteoarthritis.

Quantifying sustained pain worsening in knee osteoarthritis

OBJECTIVE

Recent work suggests that many persons with knee osteoarthritis (OA) experience stable symptoms over time. Whether patients experience periods of symptom exacerbation or flare which interrupt this stable course, and how long such periods last, has received little study. Our objective is to describe the frequency and duration of episodes of pain worsening in persons with knee OA.

METHODS

We selected participants from the Osteoarthritis Initiative with radiographic, symptomatic knee OA. We defined a clinically relevant increase in knee pain as an increase in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain of ≥9 points. We defined sustained worsening as maintaining at least 80% of the initial increase. We used Poisson regression to estimate the incidence rate (IR) of episodes of pain worsening.

RESULTS

1093 participants were included in the analysis. Eighty-eight percent had ≥1 increase in WOMAC pain ≥9 points (IR: 26.3 per 100 person years (95% CI: 25.2, 27.4)). Forty-eight percent had ≥1 episode of sustained worsening (IR: 9.7 per 100 person-years (95% CI: 8.9, 10.5)). Elevated pain was maintained an average of 2.4 years after the initial increase.

CONCLUSION

Most participants with knee OA reported at least one clinically relevant increase in WOMAC pain, but fewer than half experienced an episode of sustained pain worsening. These individual-level data portray a more nuanced and fluctuating course of OA pain than suggested by trajectory studies. These data could be useful in shared decision-making regarding prognosis and treatment choices in persons affected by symptomatic knee OA.

Implantable Shock Absorber Provides Superior Pain Relief and Functional Improvement Compared With High Tibial Osteotomy in Patients with Mild-to-Moderate Medial Knee Osteoarthritis: A 2-Year Report

OBJECTIVE

Up to 10 million Americans below the age of 65 years have symptomatic knee osteoarthritis (OA) and may not yet be candidates for arthroplasty. In response, a subcutaneous implantable shock absorber (ISA) that unloads the knee has been developed. The safety and effectiveness of ISA treatment were compared against a surgical unloading control, high tibial osteotomy (HTO).

DESIGN

This was a prospective open-label cohort study with a historical control arm. Subjects underwent ISA placement or HTO. The primary endpoint was a composite variable combining pain, function, specific adverse events, integrity of implant or hardware, and conversion to subsequent surgery. Pain and function outcomes (Western Ontario and McMaster Universities Arthritis Index scores) were assessed through 24 months. Adverse events were tracked.

RESULTS

The primary endpoint demonstrated superiority of the ISA arm versus the HTO arm, with 85.6% of ISA subjects meeting all criteria compared with 65.5% of HTO subjects. In addition, all 5 secondary endpoints showed superiority of ISA over HTO. At 24 months, the proportions of subjects considered responders were 95.8% (ISA) versus 87.9% (HTO) for pain and 91.7% (ISA) versus 81.3% (HTO) for function. The ISA procedure was well tolerated, with 13.4 days to full weightbearing status versus 58.0 days for the HTO arm.

CONCLUSIONS

Treatment with an ISA demonstrated noninferiority and superiority versus treatment with HTO in subjects aged 25-65 years who had OA of the medial knee. Treatment with ISA has high clinical benefit and is durable through at least 24 months.

The interplay between symptoms of insomnia and pain in people with osteoarthritis: A narrative review of the current evidence

Osteoarthritis (OA) is a leading cause of disability worldwide and clinical pain is the major symptom of OA. This clinical OA-related pain is firmly associated with symptoms of insomnia, which are reported in up to 81% of people with OA. Since understanding the association between both symptoms is critical for their appropriate management, this narrative review synthesizes the existing evidence in people with OA on i) the mechanisms underlying the association between insomnia symptoms and clinical OA-related pain, and ii) the effectiveness of conservative non-pharmacological treatments on insomnia symptoms and clinical OA-related pain. The evidence available identifies depressive symptoms, pain catastrophizing and pain self-efficacy as mechanisms partially explaining the cross-sectional association between insomnia symptoms and pain in people with OA. Furthermore, in comparison to treatments without a specific insomnia intervention, the ones including an insomnia intervention appear more effective for improving insomnia symptoms, but not for reducing clinical OA-related pain. However, at a within-person level, treatment-related positive effects on insomnia symptoms are associated with a long-term pain reduction. Future longitudinal prospective studies offering fundamental insights into neurobiological and psychosocial mechanisms explaining the association between insomnia symptoms and clinical OA-related pain will enable the development of effective treatments targeting both symptoms.

Magnetic resonance imaging assessments for knee segmentation and their use in combination with machine/deep learning as predictors of early osteoarthritis diagnosis and prognosis

Knee osteoarthritis (OA) is a prevalent and disabling disease that can develop over decades. This disease is heterogeneous and involves structural changes in the whole joint, encompassing multiple tissue types. Detecting OA before the onset of irreversible changes is crucial for early management, and this could be achieved by allowing knee tissue visualization and quantifying their changes over time. Although some imaging modalities are available for knee structure assessment, magnetic resonance imaging (MRI) is preferred. This narrative review looks at existing literature, first on MRI-developed approaches for evaluating knee articular tissues, and second on prediction using machine/deep-learning-based methodologies and MRI as input or outcome for early OA diagnosis and prognosis. A substantial number of MRI methodologies have been developed to assess several knee tissues in a semi-quantitative and quantitative fashion using manual, semi-automated and fully automated systems. This dynamic field has grown substantially since the advent of machine/deep learning. Another active area is predictive modelling using machine/deep-learning methodologies enabling robust early OA diagnosis/prognosis. Moreover, incorporating MRI markers as input/outcome in such predictive models is important for a more accurate OA structural diagnosis/prognosis. The main limitation of their usage is the ability to move them in rheumatology practice. In conclusion, MRI knee tissue determination and quantification provide early indicators for individuals at high risk of developing this disease or for patient prognosis. Such assessment of knee tissues, combined with the development of models/tools from machine/deep learning using, in addition to other parameters, MRI markers for early diagnosis/prognosis, will maximize opportunities for individualized risk assessment for use in clinical practice permitting precision medicine. Future efforts should be made to integrate such prediction models into open access, allowing early disease management to prevent or delay the OA outcome.

The effect of oral administration of undenatured type II collagen on monosodium iodoacetate-induced osteoarthritis in young and old rats

We investigated whether different doses of undenatured type II collagen (undenatured collagen, UC-II) help improve monosodium iodoacetate (MIA)-induced (osteoarthritis) OA in young and old rats. A total of 70 rats were divided into five groups: (1) control; (2) MIA (a single intra-articular injection of MIA); (3)-(5) MIA+ Undenatured Collagen with various oral doses (0.66, 1.33, and 2 mg/kg). The results showed that all doses of undenatured collagen in both age groups reduced knee diameter, while the two higher doses (1.33 mg/kg and 2 mg/kg) reduced the Mankin score and increased most gait measurements as early as day 14 compared to the MIA rats. However, the 2 mg/kg dose showed the best efficacy in improving Mankin score and gait measurements by 28 days post-OA induction. In young but not old rats, all doses of undenatured collagen reduced the Kellgren-Lawrence score compared to the MIA group. Undenatured collagen reduced the levels of most inflammatory and cartilage breakdown markers in serum and knee joint cartilage in both age groups. In conclusion, this data suggests that while all doses of undenatured collagen supplementation may ameliorate MIA-induced OA symptoms, the higher doses showed faster improvement in gait measurements and were more efficacious for overall joint health in rats.