Comparison of fixed-flexion positioning with fluoroscopic semi-flexed positioning for quantifying radiographic joint-space width in the knee: test-retest reproducibility

Comparing Five Major Knee Osteoarthritis Cohort Studies: Similarities, Differences, and Unique Aspects of CHECK, OAI, FNIH, IMI-APPROACH, and MOST

ObjectiveTo analyze and synthesize the information available from five pivotal, large-scale, multicenter, observational studies (CHECK, OAI, FNIH Biomarkers Consortium, IMI-APPROACH, and MOST) focusing on knee osteoarthritis (OA), which can be used to elucidate disease progression, risk factors, and the effectiveness of potential interventions.DesignFor this narrative review, a comprehensive literature search and data extraction from official web pages and scientific databases were conducted to compare methodologies, in- and exclusion criteria, outcomes, and cohort characteristics across the studies. Thematic, comparative, and qualitative analyses were employed to identify trends, commonalities, and disparities among the findings.ResultsThe studies collectively enhanced understanding of the onset and progression of knee OA, and in several of the studies, hip OA, emphasizing the importance of both systemic and local risk factors. Advanced imaging and biomarkers are important components in all the cohorts, with the goal of aiding early diagnosis and tracking disease progression. All cohorts evaluated unique markers generally not available in the other cohorts, while other factors overlap, suggesting possibilities for combining or cross-validating between cohorts.ConclusionsThe collaborative efforts of major OA research significantly advance our understanding of knee OA. These studies highlight the importance of a multifaceted approach, integrating advanced imaging, biomarkers, and longitudinal data to tackle the complexities of OA. By synthesizing findings and addressing knowledge gaps such as heterogeneity of patients and used measurements, and use of novel pain measures, future research can develop more effective diagnostic tools and treatments, ultimately enhancing the quality of life for OA patients.

Does MRI alter management in patients 60 years and older with chronic knee pain: correlation with radiographs and clinical parameters

OBJECTIVE

To determine if MRI altered management in patients ≥ 60 years old with chronic knee pain.

MATERIALS AND METHODS

Consecutive patients ≥ 60 years old with knee MRI and radiographs within 90 days were included. Exclusion criteria included mass/malignancy, recent trauma, and infection. Standing AP and PA flexion views were evaluated using Kellgren-Lawrence (KL) and International Knee Documentation Committee (IKDC) scales. Pertinent clinical history was recorded. MRIs were considered to alter management if subchondral fracture was identified or subsequent arthroscopy was performed due to an MRI finding.

RESULTS

Eighty-five knee MRI/radiograph exams were reviewed; mean 68.2 years (60-88), 47:38 F:M. Twenty knee MRIs (24%) had either a subchondral fracture (n = 9) or meniscal tear (n = 11) prompting arthroscopy. On PA flexion view, 0/20 of these studies had KL grade 4 and 70% (14/20) had KL grade 0-1 compared to the remaining MRIs having 15.4% (10/65) KL grade 4 and 38.5% (25/65) KL grade 0-1 (p = 0.03). A 10-pack-year tobacco history, 38% vs 18%, was associated with a subchondral fracture or arthroscopy (p = 0.06). Subchondral fractures were more prevalent in older patients (mean 72.4 vs 67.7 years; p = 0.03).

CONCLUSION

In patients ≥ 60 years old with chronic knee pain, MRI altered management in ~ 24% of cases; 70% in patients with KL grade 0-1, and none in patients with KL grade 4. MRI may benefit older patients with minimal osteoarthritis but not those with end-stage disease. Patients with ≥ 10 pack years of smoking may also benefit from MRI.

Femorotibial angle scan-rescan reproducibility: A high-precision calculation on a large cohort

PURPOSE

Femorotibial angle (FTA) is a convenient measure of coronal knee alignment that can be extracted from a short knee radiograph, avoiding the additional radiation exposure and specialist equipment required for full-leg radiographs. While intra- and inter-reader reproducibility from the same image has been reported, the full scan-rescan reproducibility across images, as calculated in this study, has not.

METHODS

In this study, 4589 FTA measurement pairs from 2586 subjects acquired a year apart were used to estimate FTA scan-rescan reproducibility using data from the Osteoarthritis Initiative. Subjects with radiographic progression of osteoarthritis or other conditions that may cause a change in coronal knee alignment were excluded. Measurement pairs were analysed using paired-samples t tests to detect differences and compared to symptomatic changes in Western Ontario and McMaster Universities Arthritis Index scores for joint pain, stiffness and physical function to detect correlations.

RESULTS

The 95% limit of agreement and the paired-samples correlation were calculated with high precision to be [-1.76°, +1.78°] and 0.938, considerably worse than the corresponding figures for intra- and inter-reader reproducibility, without relation to symptomatic or radiographic changes in knee condition. This error will weakly attenuateR 2 andr values from their true values in correlative studies involving FTA. The realistic maximum value forR 2 is 87% and for Pearson'sr is 93%.

CONCLUSION

The scan-rescan reproducibility in FTA is almost double the intra- and inter-reader reliability from a single scan. At almost ±2° accuracy, FTA is inappropriate for surgical use, but it is sufficiently reproducible to produce good correlations in studies predicting disease incidence and progression.

LEVEL OF EVIDENCE

Level II, retrospective study.

Sexual dimorphism in articular tissue anatomy - Key to understanding sex differences in osteoarthritis?

OBJECTIVE

Osteoarthritis (OA) prevalence and incidence varies between women and men, but it is unknown whether this follows sex-specific differences in systemic factors (e.g. hormones) and/or differences in pre-morbid joint anatomy. We recognize that classifications of sex within humans cannot be reduced to female/male, but given the lack of literature on non-binary individuals, this review is limited to the sexual dimorphism of articular morphotypes.

METHODS

Based on a Pubmed search using relevant terms, and input from experts, we selected articles based on the authors' judgment of their relevance, interest, originality, and scientific quality; no "hard" bibliometric measures were used to evaluate their quality or importance. Focus was on clinical rather than pre-clinical studies, with most (imaging) data being available for the knee joint.

RESULTS

After introducing "sexual dimorphism", the specific literature on articular morphotypes is reviewed, structured by: radiographic joint space width (JSW), meniscus, ligaments, articular cartilage morphology, articular cartilage composition and deformation, and articular tissue response to treatment.

CONCLUSIONS

Sex-specific differences were clearly observed for JSW, meniscus damage, ligament size, and cartilage morphometry (volume, thickness, and surface areas) but not for cartilage composition. Ligament and cartilage measures were smaller in women even after matching for confounders. Taken together, the findings indicate that female (knee) joints may be structurally more vulnerable and at greater risk of OA. The "one size/sex fits all" approach must be abandoned in OA research, and all observational and interventional studies should report their results for sex-specific strata, at least in pre-specified secondary or post-hoc analyses.

Accurate tibial tunnel position in transtibial pullout repair for medial meniscus posterior root tears delays the progression of medial joint space narrowing

PURPOSE

This study aimed to evaluate the association between the progression of medial joint space (MJS) narrowing, medial meniscus extrusion (MME) and clinical scores and the tibial tunnel position in pullout repairs for medial meniscus posterior root tears (MMPRTs).

METHODS

This retrospective study examined 54 patients. Changes in MJS (ΔMJS), MME (ΔMME) and clinical scores and their relationship with the tibial tunnel position were evaluated using correlation coefficients. The distance from the anatomical to technical attachment position in the tibial tunnel position was measured in the anterior and medial directions, and the direct distance was measured using the Pythagorean theorem.

RESULTS

The mean ΔMJS and ΔMME were 0.6 ± 0.8 and 1.3 ± 1.3 mm, respectively, and the mean anterior, medial and direct distances were 1.4 ± 2.3, 2.2 ± 1.7 and 3.4 ± 1.7 mm, respectively. ΔMJS had a significant positive correlation with the medial (r = 0.580, p < 0.001) and direct (r = 0.559, p < 0.001) distances, while ΔMME had a significant positive correlation with direct distance (r = 0.295, p = 0.030). Several clinical scores were significantly negatively correlated with these distances.

CONCLUSION

In transtibial pullout repair for MMPRTs, accurate tibial tunnel position delayed the progression of MJS narrowing and MME, leading to improved clinical outcomes. The progression of MJS narrowing was associated with the mediolateral direction of the tibial tunnel position, while the clinical scores were associated with the anteroposterior direction of the tibial tunnel position. These findings indicate the need to orient the tip of the guide in a more posterolateral direction when creating the tibial tunnel.

LEVEL OF EVIDENCE

Level IV.

Evaluation of the effect of low-intensity pulsed ultrasound in pain and dysfunction for knee osteoarthritis: a double-blind, randomised controlled trial protocol

INTRODUCTION

Osteoarthritis (OA) is the most common joint disorder among musculoskeletal conditions. Non-surgical treatment is the standard therapy for knee OA (KOA). Ultrasound therapy is recommended for alleviating pain and dysfunction from OA, but high-quality scientific evidence for its effectiveness in OA treatment is still lacking.Therefore, we want to analyse whether combining conventional physical therapy with low-intensity pulsed ultrasound (LIPUS) can enhance the efficacy of conventional therapy, thus improving symptoms in patients with KOA.

METHODS AND ANALYSIS

This randomised controlled trial aims to recruit 200 patients diagnosed with KOA, aged 38 years or above, who meet the clinical diagnostic criteria for KOA. Patients will be randomly assigned in a 1:1 ratio to either a LIPUS treatment group or a sham ultrasound treatment control group. The 2-week treatment will consist of five sessions per week and evaluations will take place at baseline, on the day of the last intervention and 1 month post intervention. The main outcome measures will be the Western Ontario and McMaster Universities' scores. Secondary outcome indicators will be the Numerical Pain Rating Scale, the Lequesne scale, the time up and go test and the range of motion of the knee. An intention-to-treat analysis will be performed for dropouts and missing data.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of Shengjing Hospital of China Medical University (2023PS592K). Findings will be disseminated to participants and made available to peer-reviewed journals.

TRIAL REGISTRATION NUMBER

The trial was registered on the Chinese Clinical Trial Registry platform (chictr.org.cn) on 22 March 2023, with the registration ID ChiCTR2300069643.

Autologous Chondrocyte Implantation Is Not Better Than Arthroscopic Debridement for the Treatment of Symptomatic Cartilage Lesions of the Knee: Two-Year Results From a Randomized-Controlled Trial

Purpose

To compare the functional and patient-reported outcome measures after autologous chondrocyte implantation (ACI) and arthroscopic debridement (AD) in symptomatic, isolated cartilage injuries larger than 2 cm2 in patients aged 18 to 50 years.

Methods

Twenty-eight patients were included and randomized to ACI (n = 15) or AD (n = 13) and followed for 2 years. The primary outcome was the change in the Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscale.

Results

The mean age at inclusion was 34.1 (standard deviation [SD] 8.5) years. There were 19 (68%) male patients. The mean size of the lesion was 4.2 (SD 1.7) cm2. There was a statistically significant and clinically meaningful improvement in patient-reported outcome measures from baseline to 2 years in both groups. The improvement from baseline to final follow-up for the primary endpoint (the KOOS QoL subscale) was larger for the AD group (39.8, SD 9.4) compared with the ACI group (23.8, SD 6.7), but this difference was not statistically significant (P = .17). However, according to a mixed linear model there were statistically significantly greater scores in the AD group for several KOOS subscales at several time points, including KOOS QoL, KOOS pain, and KOOS sport and recreation at 2 years.

Conclusions

This study indicates that AD followed by supervised physiotherapy is equal to or better than ACI followed by supervised physiotherapy in patients with isolated cartilage lesions of the knee larger than 2 cm2. The improvement in KOOS QoL score from baseline to 2 years was clinically meaningful for both groups (23.8 points for ACI and 39.8 points AD), and larger for the AD group by 16 points.

Level of Evidence

Level I, prospective randomized controlled trial.

Imaging Biomarkers of Osteoarthritis

Currently no disease-modifying osteoarthritis drug has been approved for the treatment of osteoarthritis (OA) that can reverse, hold, or slow the progression of structural damage of OA-affected joints. The reasons for failure are manifold and include the heterogeneity of structural disease of the OA joint at trial inclusion, and the sensitivity of biomarkers used to measure a potential treatment effect.This article discusses the role and potential of different imaging biomarkers in OA research. We review the current role of radiography, as well as advances in quantitative three-dimensional morphological cartilage assessment and semiquantitative whole-organ assessment of OA. Although magnetic resonance imaging has evolved as the leading imaging method in OA research, recent developments in computed tomography are also discussed briefly. Finally, we address the experience from the Foundation for the National Institutes of Health Biomarker Consortium biomarker qualification study and the future role of artificial intelligence.

Medial joint space narrowing progresses after pullout repair of medial meniscus posterior root tear

PURPOSE

The extent to which arthropathic changes progress after medial meniscus posterior root tear (MMPRT) repair remains controversial. This retrospective study assessed medial joint space (MJS) narrowing progression after pullout repair for MMPRT and identified the correlating factors.

METHODS

We included 56 patients who underwent pullout repair for MMPRT. The MJS of the bilateral knees was assessed with radiography using the fixed-flexion view. A second-look arthroscopy was performed one year post-operatively for all patients. The baseline characteristics, clinical scores, Kellgren-Lawrence (KL) grade, and medial meniscus extrusion (MME) were identified. Statistical comparisons and correlation analyses were conducted.

RESULTS

The MJS narrowing width was significantly larger in MMPRT knees than in contralateral knees (0.51 ± 0.85 mm vs. 0.09 ± 0.49 mm, p < 0.001). KL grade progression was observed in 23.2% (13/56) of patients. There was a significant difference between pre- and post-operative MME values, indicating MME progression (p < 0.001). Each clinical score showed significant improvement one year post-operatively (p < 0.001). Positive correlations were found between MJS narrowing and pre-operative MJS (coefficient = 0.510, p < 0.001), rate of change in MJS (coefficient = 0.929, p < 0.001), and increase in MME (ΔMME) (coefficient = 0.506, p < 0.001).

CONCLUSION

Knees that underwent pullout repair for MMPRT showed progression of MJS narrowing by 0.51 mm at one year post-operatively, although clinical scores markedly improved. Correlating factors for MJS narrowing were pre-operative MJS, rate of change in MJS, and ΔMME. Preventing MME progression is essential for preventing arthropathic changes.

Development of a nomogram prediction model for gait speed trajectories in persons with knee osteoarthritis

To examine heterogeneous trajectories of 8-year gait speed among patients with symptomatic knee osteoarthritis (KOA) and to develop a nomogram prediction model. We analyzed data from the Osteoarthritis Initiative (OAI) assessed at baseline and follow-up over 8 years (n = 1289). Gait speed was measured by the 20-m walk test. The gait speed trajectories among patients with KOA were explored by latent class growth analysis. A nomogram prediction model was created based on multivariable logistic regression. Three gait speed trajectories were identified: the fast gait speed group (30.4%), moderate gait speed group (50.5%) and slow gait speed group (19.1%). Age ≥ 60 years, female, non-white, nonmarried, annual income < $50,000, obesity, depressive symptoms, comorbidity and WOMAC pain score ≥ 5 were risk factors for the slow gait trajectory. The area under the ROC curve of the prediction model was 0.775 (95% CI 0.742-0.808). In the external validation cohort, the AUC was 0.773 (95% CI 0.697-0.848). Heterogeneous trajectories existed in the gait speed of patients with KOA and could be predicted by multiple factors. Risk factors should be earlier identified, and targeted intervention should be carried out to improve physical function of KOA patients.

Improved responsiveness to change in joint space width over 24-month follow-up: comparison of 3D JSW on weight-bearing CT vs 2D JSW on radiographs in the MOST study

OBJECTIVE

Radiographic joint space width (JSW) has been a standard for measuring knee osteoarthritis (OA) structural change. Limitations in the responsiveness of this approach might be overcome by instead measuring 3D JSW on weight-bearing CT (WBCT). This study compared the responsiveness of 3D JSW measurements using WBCT with the responsiveness of radiographic 2D JSW.

DESIGN

Standing, fixed-flexion knee radiographs (XR) and WBCT were acquired ancillary to the 144- and 168-month Multicenter Osteoarthritis Study visits. Tibiofemoral JSW was measured on both XR and WBCT. Responsiveness to change was defined by the standardized response mean (SRM) for change in JSW (1) at predetermined mediolateral locations (JSWx) on both modalities and (2) in the following subregions measured on WBCT images: central medial and lateral femur (CMF/CLF) and tibia (CMT/CLT), and anterior and posterior tibia (AMT/ALT, PMT/MLT).

RESULTS

Baseline and 24-month follow-up JSWx measurements were completed for 265 participants (58.1% women). Responsiveness of 3D JSWx for medial tibiofemoral compartment on coronal WBCT (SRM range: -0.18, -0.24) exceeded that for 2D JSWx (-0.10, -0.16). Responsiveness of 3D JSW subregional mean (-0.06, -0.36) and maximal (-1.14, -1.75) CMF and CMT and maximal CLF/CLT 3D JSW changes were statistically significantly greater in comparison with respective medial and lateral 2D JSWx (P ≤ 0.002).

CONCLUSIONS

Subregional 3D JSW on WBCT is substantially more responsive to 24-month changes in tibiofemoral joint structure compared to radiographic measurements. Use of subregional 3D JSW on WBCT could enable improved detection of OA structural progression over a 24-month duration in comparison with measurements made on XR.

Artificial intelligence-based computer-aided system for knee osteoarthritis assessment increases experienced orthopaedic surgeons' agreement rate and accuracy

PURPOSE

The aims of this study were to (1) analyze the impact of an artificial intelligence (AI)-based computer system on the accuracy and agreement rate of board-certified orthopaedic surgeons (= senior readers) to detect X-ray features indicative of knee OA in comparison to unaided assessment and (2) compare the results to those of senior residents (= junior readers).

METHODS

One hundred and twenty-four unilateral knee X-rays from the OAI study were analyzed regarding Kellgren-Lawrence grade, joint space narrowing (JSN), sclerosis and osteophyte OARSI grade by computerized methods. Images were rated for these parameters by three senior readers using two modalities: plain X-ray (unaided) and X-ray presented alongside reports from a computer-assisted detection system (aided). After exclusion of nine images with incomplete annotation, intraclass correlations between readers were calculated for both modalities among 115 images, and reader performance was compared to ground truth (OAI consensus). Accuracy, sensitivity and specificity were also calculated and the results were compared to those from a previous study on junior readers.

RESULTS

With the aided modality, senior reader agreement rates for KL grade (2.0-fold), sclerosis (1.42-fold), JSN (1.37-fold) and osteophyte OARSI grades (3.33-fold) improved significantly. Reader specificity and accuracy increased significantly for all features when using the aided modality compared to the gold standard. On the other hand, sensitivity only increased for OA diagnosis, whereas it decreased (without statistical significance) for all other features. With aided analysis, senior readers reached similar agreement and accuracy rates as junior readers, with both surpassing AI performance.

CONCLUSION

The introduction of AI-based computer-aided assessment systems can increase the agreement rate and overall accuracy for knee OA diagnosis among board-certified orthopaedic surgeons. Thus, use of this software may improve the standard of care for knee OA detection and diagnosis in the future.

LEVEL OF EVIDENCE

Level II.

Changes in joint space width over time and risk factors for deterioration of joint space width after medial opening-wedge high tibial osteotomy

PURPOSE

The purpose of this study was to evaluate the changes in joint space width (JSW) over time after medial opening-wedge high tibial osteotomy (MOWHTO) and identify risk factors for deterioration of JSW using anteroposterior (AP) and Rosenberg views.

METHODS

We retrospectively analyzed changes in JSW of 104 MOWHTO patients whose preoperative osteoarthritis (OA) grade was K-L grade 3 or less on AP and Rosenberg views. Serial changes in JSW were assessed from preoperatively to at least 3 years postoperatively. Patients were divided into two groups according to JSW change patterns on each of AP and Rosenberg views: non-deterioration group had either unchanged or increased JSW, and deterioration group had decreased JSW. Clinical outcomes were compared using Western Ontario and McMaster Universities OA Index (WOMAC) score between groups. Multivariate logistic regression analysis was performed to identify risk factors for deterioration of JSW.

RESULTS

JSW on average for all patients increased 0.5 mm and 0.8 mm on AP and Rosenberg views, respectively (p < 0.05). Non-deterioration group showed significant improvement based on patient-reported outcomes (WOMAC) than deterioration group (all p < 0.05). Undercorrection was an independent risk factor for failure to achieve maintained or increased JSW on both AP (OR 6.885, 95% CI 1.976-23.986, p = 0.002) and Rosenberg (OR 12.756, 95% CI 2.952-55.129, p = 0.001) views.

CONCLUSION

JSW increased gradually and continuously on standing AP and Rosenberg views until postoperative 3 years after MOWHTO. Deterioration of JSW following MOWHTO was closely related to the undercorrection and affected clinical outcomes.

LEVEL OF EVIDENCE

Level III, case control study.

Orang Asli Health and Lifeways Project (OA HeLP): a cross-sectional cohort study protocol

INTRODUCTION

Non-communicable disease (NCD) risk is influenced by environmental factors that are highly variable worldwide, yet prior research has focused mainly on high-income countries where most people are exposed to relatively homogeneous and static environments. Understanding the scope and complexity of environmental influences on NCD risk around the globe requires more data from people living in diverse and changing environments. Our project will investigate the prevalence and environmental causes of NCDs among the indigenous peoples of Peninsular Malaysia, known collectively as the Orang Asli, who are currently undergoing varying degrees of lifestyle and sociocultural changes that are predicted to increase vulnerability to NCDs, particularly metabolic disorders and musculoskeletal degenerative diseases.

METHODS AND ANALYSIS

Biospecimen sampling and screening for a suite of NCDs (eg, cardiovascular disease, type II diabetes, osteoarthritis and osteoporosis), combined with detailed ethnographic work to assess key lifestyle and sociocultural variables (eg, diet, physical activity and wealth), will take place in Orang Asli communities spanning a gradient from remote, traditional villages to acculturated, market-integrated urban areas. Analyses will first test for relationships between environmental variables, NCD risk factors and NCD occurrence to investigate how environmental changes are affecting NCD susceptibility among the Orang Asli. Second, we will examine potential molecular and physiological mechanisms (eg, epigenetics and systemic inflammation) that mediate environmental effects on health. Third, we will identify intrinsic (eg, age and sex) and extrinsic (eg, early-life experiences) factors that predispose certain people to NCDs in the face of environmental change to better understand which Orang Asli are at greatest risk of NCDs.

ETHICS AND DISSEMINATION

Approval was obtained from multiple ethical review boards including the Malaysian Ministry of Health. This study follows established principles for ethical biomedical research among vulnerable indigenous communities, including fostering collaboration, building cultural competency, enhancing transparency, supporting capacity building and disseminating research findings.

Increased risk of incident knee osteoarthritis in those with greater work-related physical activity

OBJECTIVE

Occupations involving greater physical activity may increase risk for knee osteoarthritis (OA). Existing studies have not evaluated work-related physical activity before OA onset. Hence, we aimed to evaluate the association between work-related physical activity and knee OA incidence.

METHODS

We performed a person-based longitudinal study using Osteoarthritis Initiative (OAI) data among people who volunteered or worked for pay without baseline radiographic knee OA or knee pain. Bilateral knee radiographs were obtained at baseline and annual follow-ups. We defined radiographic OA as Kellgren-Lawrence grade ≥2. Questions from the Physical Activity Scale for the Elderly at baseline and annual OAI visits provided information about work-related physical activity level and hours. We performed logistic regression with work-related physical activity level ( mainly sitting , standing and some walking , walking while handling some materials ) and hours as predictors. The outcome was incident person-based radiographic OA within the ensuing 12 months, over 48 months.

RESULTS

Among 951 participants (2819 observations), higher work-related physical activity levels had greater adjusted ORs for incident radiographic OA (people with jobs with standing and some walking : 1.11 (0.60-2.08), and walking while handling some materials : 1.90 (1.03-3.52), when compared with those with mainly sitting work-related activity ). There was no association between number of hours worked and incident radiographic OA.

CONCLUSIONS

People performing work that require walking while handling some materials have greater odds of incident knee OA than those with jobs mostly involving sitting. Strategies are needed to mitigate risk factors predisposing them to radiographic OA.

Irregular types of proximal tibiofibular joint increase the risk of total knee replacement: Data from the osteoarthritis initiative

The study aimed to determine the associations between the morphological types of proximal tibiofibular joint (PTFJ) and the risk of total knee replacement (TKR) in a cohort of participants with progressive osteoarthritis. A nested case-control design was performed in Osteoarthritis Initiative study. The case knees were those with TKR at 24-60 months follow up (cases), and were 1:1 matched with control knees by age, sex, and Kellgren-Lawrence grade at baseline. The morphological type of each PTFJ was identified according to the coronal and sagittal MR images. Conditional logistic regression models were used to examine the association of the PTFJ types with the risk of TKR at baseline and the time point before TKR (T₀ ). A total of 193 case knees at baseline and 148 case knees at T₀ time point had matched controls between 12 and 60 M. Seven types of the PTFJ were identified and classified into three categories: plane, trochoid, and irregular types. The prevalence of the irregular type was higher in case knees than in controls both at baseline (cases vs. controls, 35.8% vs. 26.9%) and at T₀ time point (cases vs. controls, 33.1% vs. 27.0%). The irregular type of the PTFJ at baseline (odds ratio: 1.62, 95% confidence interval: 1.01-2.59) rather than at T₀ time point was significantly associated with increased odds of TKR. The irregular types of the PTFJ at baseline are associated with increased risk of TKR, suggesting PTFJ may play a role in knee osteoarthritis.

Imaging in Osteoarthritis

Osteoarthritis (OA) is the most frequent form of arthritis with major implications on both individual and public health care levels. The field of joint imaging, and particularly magnetic resonance imaging (MRI), has evolved rapidly due to the application of technical advances to the field of clinical research. This narrative review will provide an introduction to the different aspects of OA imaging aimed at an audience of scientists, clinicians, students, industry employees, and others who are interested in OA but who do not necessarily focus on OA. The current role of radiography and recent advances in measuring joint space width will be discussed. The status of cartilage morphology assessment and evaluation of cartilage biochemical composition will be presented. Advances in quantitative three-dimensional morphologic cartilage assessment and semi-quantitative whole-organ assessment of OA will be reviewed. Although MRI has evolved as the most important imaging method used in OA research, other modalities such as ultrasound, computed tomography, and metabolic imaging play a complementary role and will also be discussed.

Heterogeneity of cartilage damage in Kellgren and Lawrence grade 2 and 3 knees: the MOST study

OBJECTIVE

Eligibility for clinical trials in osteoarthritis (OA) is usually limited to Kellgren-Lawrence (KL) grades 2 and 3 knees. Our aim was to describe the prevalence and severity of cartilage damage in KL 2 and 3 knees by compartment and articular subregion.

DESIGN

The Multicenter Osteoarthritis (MOST) study is a cohort study of individuals with or at risk for knee OA. All baseline MRIs with radiographic disease severity KL2 and 3 were included. Knee MRIs were read for cartilage damage in 14 subregions. We determined the frequencies of no, any and widespread full-thickness cartilage damage by knee compartment, and the prevalence of any cartilage damage in 14 articular subregions.

RESULTS

665 knees from 665 participants were included (mean age 63.8 ± 7.9 years, 66.5% women). 372 knees were KL2 and 293 knees were KL3. There was no cartilage damage in 78 (21.0%) medial tibio-femoral joint (TFJ), 157 (42.2%) lateral TFJ and 62 (16.7%) patello-femoral joint (PFJ) compartments of KL2 knees, and 17 (5.8%), 115 (39.3%) and 35 (12.0%) compartments, respectively, of KL3 knees. There was widespread full-thickness damage in 94 (25.3%) medial TFJ, 36 (9.7%) lateral TFJ and 176 (47.3%) PFJ compartments of KL2 knees, and 217 (74.1%), 70 (23.9%) and 104 (35.5%) compartments, respectively, of KL3 knees. The subregions most likely to have any damage were central medial femur (80.5%), medial patella (69.8%) and central medial tibia (69.9).

CONCLUSIONS

KL2 and KL3 knees vary greatly in cartilage morphology. Heterogeneity in the prevalence, severity and location of cartilage damage in in KL2 and 3 knees should be considered when planning disease modifying trials for knee OA.

SPHARM-PDM based image preprocessing pipeline for quantitative morphometric analysis (QMA) for in situ joint assessment in rabbit and rat models

The accessibility of quantitative measurements of joint morphometry depends on appropriate tibial alignment and volume of interest (VOI) selection of joint compartments; often a challenging and time-consuming manual task. In this work, we developed a novel automatic, efficient, and model-invariant image preprocessing pipeline that allows for highly reproducible 3D quantitative morphometric analysis (QMA) of the joint. The pipeline addresses the problem by deploying two modules: an alignment module and a subdivision module. Alignment is achieved by representing the tibia in its basic form using lower degree spherical harmonic basis functions and aligning using principal component analysis. The second module subdivides the joint into lateral and medial VOIs via a watershedding approach based on persistence homology. Multiple repeated micro-computed tomography scans of small (rat) and medium (rabbit) animal knees were processed using the pipeline to demonstrate model invariance. Existing QMA was performed to evaluate the pipeline’s ability to generate reproducible measurements. Intraclass correlation coefficient and mean-normalised root-mean-squared error of more than 0.75 and lower than 9.5%, respectively, were achieved for joint centre of mass, joint contact area under virtual loading, joint space width, and joint space volume. Processing time and technical requirements were reduced compared to manual processing in previous studies.

Sleep Disturbance Trajectories in Osteoarthritis

BACKGROUND/OBJECTIVE

Sleep disturbance is common among adults with osteoarthritis (OA), but little is known about patterns over time. In this cohort study, we identified restless sleep trajectories and associated factors in adults with or at high risk for knee OA.

METHODS

Longitudinal (2004-2014) restless sleep (≥3 nights/week) annual reports over 8 years from 4359 Osteoarthritis Initiative participants were analyzed. Group-based trajectory modeling identified heterogeneous temporal patterns. Logistic regression identified baseline health and behavioral predictors of trajectory membership.

RESULTS

Four restless sleep trajectory groups were identified: good (69.7%, persistently low restless sleep probabilities), worsening (9.1%), improving (11.7%), and poor (9.5%, persistently high). Among 2 groups initially having low restless sleep prevalence, the worsening trajectory group had an increased likelihood of baseline cardiovascular disease (odds ratio [OR], 1.53; 95% confidence interval [CI], 1.01-2.33), pulmonary disease (OR, 1.48; 95% CI, 1.07-2.05), lower physical activity (OR, 1.29; 95% CI, 1.03-1.61), knee pain (OR, 1.04; 95% CI, 1.00-1.07), depressive symptoms (OR, 1.03; 95% CI, 1.01-1.06), and a decreased likelihood of better mental health (OR, 0.97; 95% CI, 0.95-0.98) at baseline. Among 2 groups initially having high restless sleep prevalence, the poor group had an increased likelihood of baseline depressive symptoms (OR, 1.03; 95% CI, 1.00-1.05).

CONCLUSIONS

Four trajectories of restless sleep over 8 years were identified using data collected from over 4000 older adults aged 45 to 79 years with or at higher risk for knee OA. The presence of depressive symptoms, less physical activity, knee pain, poor mental health, cardiovascular disease, or pulmonary disease was each associated with unfavorable trajectories.

Association between Patellofemoral and medial Tibiofemoral compartment osteoarthritis progression: exploring the effect of body weight using longitudinal data from osteoarthritis initiative (OAI)

OBJECTIVES

To investigate the associations of medial and lateral patellofemoral osteoarthritis (PF-OA) at baseline with symptomatic and radiographic OA outcomes in the medial tibiofemoral compartment (MTFC) over 4 years, according to baseline overweight status.

METHODS

Data and MRI images of 600 subjects in the FNIH-OA biomarkers consortium were used. Symptomatic worsening and radiographic progression of MTFC-OA were defined using Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain scores and MTFC joint space narrowing (JSN) from baseline to 4-year follow-up. Baseline MRIs were read to establish PF-OA diagnosis. The association between baseline regional PF-OA pattern and odds for MTFC-OA progression was evaluated using regression models (adjusted for relevant confounding covariates including body mass index (BMI), age, sex, PF alignment measurements, KL grade, and knee alignment). To evaluate the effect modifying role for overweight status, stratification analysis was performed (BMI ≥ 25 vs. < 25 kg/m²).

RESULTS

At baseline, 340 (56.7%), 255 (42.5%), and 199 (33.2%) subjects had OA in the medial, lateral, and both PF compartments. Baseline medial PF-OA was associated with WOMAC pain score and MTFC JSN progression at 4 years (Adjusted OR:1.56[95%CI:1.09-2.23] and 1.59[1.11-2.28], respectively) but not lateral PF-OA. In stratification analysis, overweight status was found to be an effect modifier for medial PF-OA and WOMAC pain (OR in overweight vs. non-overweight subjects:1.65[1.13-2.42] vs. 0.50[0.12-1.82]) as well as MTFC-JSN progression (1.63[1.12-2.4] vs. 0.75[0.19-2.81]).

CONCLUSIONS

In addition to the known confounding effect of BMI for PF-OA and MTFC-OA, the overweight status may also play an effect modifier role in the association between baseline medial PF-OA and MTFC-OA progression, which is amenable to secondary prevention.

Characterization of the mid-coronal plane method for measurement of radiographic change in knee joint space width across different levels of image parallax

OBJECTIVE

Radiographic measurement of the change in knee joint space width (ΔJSW) is often affected by image parallax, which causes an apparent exaggeration of JSW due to projectional differences. This issue with parallax (quantified by intermargin distance) can in part be addressed with a novel mid-coronal plane (MCP) measurement method. The objectives of the study were to determine 1) accuracy and 2) reproducibility of the MCP method, and 3) compare the MCP method to that used in the Osteoarthritis Initiative (OAI) for different categories of parallax.

METHODS

Posteroanterior radiographs (n = 70) with known JSW were digitally reconstructed from CT images of cadaver knees and used to determine the accuracy of ΔJSW using the MCP method for parallax categories of None, Mild/Moderate, and Severe. Reproducibility was determined from pairs of clinical radiographs selected from the OAI (n = 170). The MCP method was also compared to the OAI methodology. Both reproducibility and agreement were characterized by Bland-Altman analysis and intraclass correlation coefficients (ICC).

RESULTS

The MCP method was accurate to 0.11 mm in cases with no parallax, and 0.18 mm across all categories of parallax for medial and lateral compartments. Reproducibility of the MCP method was graded "excellent" (ICC 0.98, 95% CI [0.98, 0.99]). The MCP results agreed very well with the OAI (ICC 0.92, 95% CI [0.89, 0.94]), with mean absolute differences between methods increasing with increasing parallax.

CONCLUSION

The MCP method is an accurate, reproducible alternative to the OAI method for multi-center clinical trials where subject and X-ray beam positioning may be variable.

Severity of valgus knee osteoarthritis has no effect on clinical outcomes after total knee arthroplasty

INTRODUCTION

Advanced valgus osteoarthritis (OA) is one of the most challenging indications for total knee arthroplasty (TKA). There is no information in the literature about the optimal timing of surgery. The current study investigates the impact of the preoperative deformity and degree of arthritis on postoperative outcome after TKA.

MATERIAL AND METHODS

The study evaluated 133 knees in 107 patients with valgus OA that failed nonoperative treatment with a minimum 2-year follow-up. Mechanical alignment, Kellgren and Lawrence (K/L) score, and minimal joint space width (minJSW) were measured on AP- and hip-to-ankle radiographs. All knees had advanced OA (i.e., K/L grades 3 or 4 and less than 50% minJSW). Pre- and postoperative WOMAC, VR-12, UCLA, VAS, ROM were recorded.

RESULTS

There was no difference in clinical outcome (WOMAC, UCLA, VR-12, VAS or ROM) between patients with different degrees of valgus deformities (< 5.0 deg., 5.0-9.9 deg., 10.0-14.9 deg., ≥ 15.0 deg.). There was also no correlation between K/L score or minimal joint space width and any of the outcome parameters.

CONCLUSIONS

The degree of valgus deformity and the grade of osteoarthritis do not predict the outcome of TKA in patients with valgus OA. Since the risk of complication and the need for implant constraint increases with increasing deformity and instability of the knee, surgery appears to be justified in patients with advanced OA that failed nonoperative treatment, regardless of the degree of deformity.

Predictive value of the morphology of proximal tibiofibular joint for total knee replacement in patients with knee osteoarthritis

The association between proximal tibiofibular joint (PTFJ) and knee osteoarthritis (OA) has been understudied. The objective of this study was to determine whether the morphology of PTFJ has predictive value for the risk of total knee replacement (TKR). Case knees from Osteoarthritis Initiative participants with TKR at 24-60 months follow up (cases) were 1:1 matched with control knees (no TKR throughout 60 months) by baseline age, sex, and Kellgren-Lawrence grade. PTFJ morphological parameters, including coronal inclination angle (angle α), sagittal inclination angle (angle β), fibular contacting area (S), load-bearing area (Sτ), lateral stress-bolstering area (Sφ), and posterior stress-bolstering area (Sυ) were assessed using coronal and sagittal magnetic resonance imaging (MRI), respectively. Associations of the morphological measures at baseline and the time point before TKR (T0 ) and their changes with TKR risks were examined using conditional logistic regression analyses. Two hundred and twenty-three knees of 193 participants received TKR between 12 and 60 months and therefore were matched with 223 control knees. Of these, 173 paired knees had MRI readings available both at baseline and T0 time point. While baseline angle α was positively associated with TKR risk, other measures at baseline and all measures at T0 were not significantly associated with TKR risk. Changes in S, Sτ, and Sυ were significantly and negatively associated with the risk of TKR (ΔS, odds ratio [OR] = 0.38, 95% confidence interval [CI]: 0.19-0.76; ΔSτ, OR = 0.37, 95% CI: 0.16-0.87; ΔSυ, OR = 0.22, 95% CI: 0.08-0.62, respectively). This data shows that morphological changes of PTFJ predict the risk of TKR, suggesting PTFJ may play a role in knee OA.

Validation of joint space narrowing on plain radiographs and its relevance to partial knee arthroplasty

AIMS

To explore the clinical relevance of joint space width (JSW) narrowing on standardized-flexion (SF) radiographs in the assessment of cartilage degeneration in specific subregions seen on MRI sequences in knee osteoarthritis (OA) with neutral, valgus, and varus alignments, and potential planning of partial knee arthroplasty.

METHODS

We retrospectively reviewed 639 subjects, aged 45 to 79 years, in the Osteoarthritis Initiative (OAI) study, who had symptomatic knees with Kellgren and Lawrence grade 2 to 4. Knees were categorized as neutral, valgus, and varus knees by measuring hip-knee-angles on hip-knee-ankle radiographs. Femorotibial JSW was measured on posteroanterior SF radiographs using a special software. The femorotibial compartment was divided into 16 subregions, and MR-tomographic measurements of cartilage volume, thickness, and subchondral bone area were documented. Linear regression with adjustment for age, sex, body mass index, and Kellgren and Lawrence grade was used.

RESULTS

We studied 345 neutral, 87 valgus, and 207 varus knees. Radiological JSW narrowing was significantly (p < 0.01) associated with cartilage volume and thickness in medial femorotibial compartment in neutral (r = 0.78, odds ratio (OR) 2.33) and varus knees (r = 0.86, OR 1.92), and in lateral tibial subregions in valgus knees (r = 0.87, OR 3.71). A significant negative correlation was found between JSW narrowing and area of subchondral bone in external lateral tibial subregion in valgus knees (r = -0.65, p < 0.01) and in external medial tibial subregion in varus knees (r = -0.77, p < 0.01). No statistically significant correlation was found in anterior and posterior subregions.

CONCLUSION

SF radiographs can be potentially used for initial detection of cartilage degeneration as assessed by MRI in medial and lateral but not in anterior or posterior subregions. Cite this article: Bone Joint Res 2021;10(3):173-187.

Scoping Review of Pain and Patient Characteristics and Physical Function Associated with Intermittent and Constant Pain in People with Knee Osteoarthritis

Purpose: We identified the pain and patient characteristics and physical function associated with intermittent and constant pain in people with knee osteoarthritis (OA). Method: The search strategy was conducted in MEDLINE, CINAHL, Embase, SPORTDiscus, Cochrane, and the Physiotherapy Evidence Database for articles published up to October 2018. We included observational studies, randomized controlled trials, reviews, qualitative studies, and case reports in English and French of adults with knee OA. Articles were screened by two independent reviewers, and disagreements were resolved by a third researcher. Results: Our search yielded 1,232 articles, and 4 articles were included in the review. Constant pain was related to limitations in daily activities, a higher Kellgren and Lawrence grade, a higher prevalence of comorbidities, and symptomatic knee OA and depressive symptoms. Intermittent pain was associated with limitations in high-impact activities, but greater time spent in moderate activities was reported. The evidence is contradictory as to whether intermittent or constant pain has a greater average severity. Conclusions: There was limited evidence available to determine the association of pain and patient characteristics and physical function with constant and intermittent pain in people with knee OA. Future research will help improve our understanding of these two pain patterns by examining their associations across a variety of pain and functional outcomes in people with knee OA.

Progression of acromegalic arthropathy in long-term controlled acromegaly patients: 9 years of longitudinal follow-up

CONTEXT

Joint complaints in patients with acromegaly are common, although the long-term disease course is largely unknown.

OBJECTIVE

This study aims to evaluate the long-term course of acromegalic arthropathy.

DESIGN AND SETTING

A prospective longitudinal cohort study was conducted in controlled acromegaly patients followed at a tertial referral center, with 3 study visits: at baseline and after a median of 2.6 and 9.1 years.

PATIENTS

We included 31 patients with biochemically controlled acromegaly for 2 or more years (49% female; median age, 60 years) at baseline.

MAIN OUTCOME MEASURES

Radiographic arthropathy of the knee, hip, hand, and cervical and lumbar spine were evaluated using Kellgren and Lawrence (KL) scores, developed for assessment of primary osteoarthritis (OA). Radiographic progression was defined as a KL increase above the smallest detectable change. Joint symptoms were assessed using self-reported questionnaires. Progression was defined using existing clinically important cutoff values. Risk factors for progression were investigated using a multivariable model.

RESULTS

All patients had definite radiographic OA at 1 or more joints at baseline. Radiographic progression was observed in 29%, 48%, 84%, and 94% of patients in the knees, hips, hands, and axial joints, respectively. Deterioration in hand-related pain and function was observed in 10 (32.3%) and 11 patients (35.5%), respectively. Solely baseline KL scores of the hip were associated with hip OA progression (OR 1.88; 95% CI, 1.09-3.16).

CONCLUSIONS

Acromegalic arthropathy showed significant radiographic progression over 9.1 years of follow-up in patients in remission, whereas clinical progression was observed less frequently. Future studies should focus on adequate prevention and treatment strategies of acromegalic arthropathy.

Determining individual trajectories of joint space loss: improved statistical methods for monitoring knee osteoarthritis disease progression

OBJECTIVES

Knee osteoarthritis (KOA) progression is frequently monitored by calculating the change in knee joint space width (JSW) measurements. Such differences are small and sensitive to measurement error. We aimed to assess the utility of two alternative statistical modelling methods for monitoring KOA.

MATERIAL AND METHODS

We used JSW on radiographs from both the control arm of the Strontium Ranelate Efficacy in Knee Osteoarthritis trial (SEKOIA), a 3-year multicentre, double-blind, placebo-controlled phase three trial, and the Osteoarthritis Initiative (OAI), an open-access longitudinal dataset from the USA comprising participants followed over 8 years. Individual estimates of annualised change obtained from frequentist linear mixed effect (LME) and Bayesian hierarchical modelling, were compared with annualised crude change, and the association of these parameters with change in WOMAC pain was examined.

RESULTS

Mean annualised JSW changes were comparable for all estimates, a reduction of around 0.14 mm/y in SEKOIA and 0.08 mm/y in OAI. The standard deviation (SD) of change estimates was lower with LME and Bayesian modelling than crude change (SEKOIA SD = 0.12, 0.12 and 0.21 respectively; OAI SD = 0.08, 0.08 and 0.11 respectively). Estimates from LME and Bayesian modelling were statistically significant predictors of change in pain in SEKOIA (LME P-value = 0.04, Bayes P-value = 0.04), while crude change did not predict change in pain (P-value = 0.10).

CONCLUSIONS

Implementation of LME or Bayesian modelling in clinical trials and epidemiological studies, would reduce sample sizes by enabling all study participants to be included in analysis regardless of incomplete follow up, and precision of change estimates would improve. They provide increased power to detect associations with other measures.

Predicting knee replacement in participants eligible for disease-modifying osteoarthritis drug treatment with structural endpoints

OBJECTIVE

Evaluate associations between 2-year change in radiographic or quantitative magnetic resonance imaging (qMRI) structural measures, and knee replacement (KR), within a subsequent 7-year follow-up period.

METHOD

Participants from the Osteoarthritis Initiative were selected based on potential eligibility criteria for a disease-modifying osteoarthritis (OA) drug trial: Kellgren-Lawrence grade 2 or 3; medial minimum joint space width (mJSW) ≥2.5 mm; knee pain at worst 4-9 in the past 30 days on an 11-point scale, or 0-3 if medication was taken for joint pain; and availability of structural measures over 2 years. Mean 2-year change in structural measures was estimated and compared with two-sample independent t-tests for KR and no KR. Area under the receiver operating characteristic curve (AUC) was estimated using 2-year change in structural measures for prediction of future KR outcomes.

RESULTS

Among 627 participants, 107 knees underwent KR during a median follow-up of 6.7 years after the 2-year imaging period. Knees that received KR during follow-up had a greater mean loss of cartilage thickness in the total femorotibial joint and medial femorotibial compartment on qMRI, as well as decline in medial fixed joint space width on radiographs, compared with knees that did not receive KR. These imaging measures had similar, although modest discrimination for future KR (AUC 0.62, 0.60, and 0.61, respectively).

CONCLUSIONS

2-year changes in qMRI femorotibial cartilage thickness and radiographic JSW measures had similar ability to discriminate future KR in participants with knee OA, suggesting that these measures are comparable biomarkers/surrogate endpoints of structural progression.

Association of circulating microRNAs with prevalent and incident knee osteoarthritis in women: the OFELY study

Objectives

In the context of the scarcity of biomarkers for knee osteoarthritis (OA), we examined the associations of prevalent and incident OA with the expression levels of serum miRNAs in subjects with and without OA.

Methods

With a next-generation sequencing approach, we compared the miRome expression of 10 women with knee OA and 10 age-matched healthy subjects. By real-time qPCR, we analyzed the expression levels of 19 miRNAs at baseline selecting 43 women with prevalent knee OA (Kellgren Lawrence score of 2/3), 23 women with incident knee OA over a 4-year follow-up and 67 healthy subjects without prevalent or incident OA matched for age and body mass index.

Results

Serum miR-146a-5p was significantly increased in the group of prevalent knee OA compared with controls (relative quantification (RQ); median [Interquartile range] 1.12 [0.73; 1.46] vs 0.85 [0.62; 1.03], p = 0.015). The likelihood of prevalent knee OA was significantly increased (odds ratio [95% confidence interval (CI)] 1.83 [1.21–2.77], p = 0.004) for each quartile increase in serum miR-146a-5p. The women with miR-146a-5p levels above the median (0.851) had a higher risk of prevalent knee OA compared to those below the median [95% CI] 4.62 [1.85–11.5], p = 0.001. Moreover, we found a significant association between the baseline level of serum miR-186-5p and the risk of incident knee OA (Q4 vs Q1–3; odds ratio [95% CI] 6.13 [1.14–32.9], p = 0.034).

Conclusion

We showed for the first time that miR-146a-5p and miR-186-5p are significantly associated with prevalent and incident knee OA, respectively.

The posterior-anterior-flexed view is essential for the evaluation of valgus osteoarthritis. A prospective study on 134 valgus knees

Background

Radiographic imaging is an important tool to assess osteoarthritis (OA). Lateral compartment osteoarthritis (valgus OA) usually starts with cartilage degeneration along the posterior aspect of the lateral femoral condyle. There is evidence that the posterior-anterior (PA)-flexed view is more sensitive when diagnosing early stages of valgus OA compared to the anterior-posterior (AP) view. The current paper analyzes the value of the PA-flexed view for patients scheduled for total knee arthroplasty (TKA).

Methods

Radiographs of 134 valgus knees were assessed prior to TKA. The minimal joint space width (minJSW) was measured on AP and PA-flexed views. The extent of mechanical deformity was measured on hip to ankle standing films.

Results

49 (36.6%) AP views showed Kellgren and Lawrence (K/L)-grade 4 osteoarthritis in the lateral compartment, 82 (63.4%) showed grade 3 or less. The PA-flexed view resulted in an increased K/L-grading to grade 4 for 53 knees (62.4%) that were considered grade 3 or less on standard AP-radiographs. There was a significant differences between lateral minJSW on AP and PA-flexed view for patients with up to 10 degrees of mechanical valgus deformity (p < 0.001), as well as 11 to 15 degrees of mechanical deformity (p = 0.021). Only knees with severe deformity of more than 15 degrees did not show a difference in minJSW between PA-flexed view and AP view (p = 0.345).

Conclusions

The PA-flexed view is superior to the standard AP view in quantifying the extent of valgus OA in patients with zero to fifteen degrees of valgus deformity. It is recommended for the initial assessment of patients with valgus osteoarthritis and better documents the extent of osteoarthritis prior to TKA.

The Relationship of Three-Dimensional Joint Space Width on Weight Bearing CT With Pain and Physical Function

Limitations of plain radiographs may contribute to poor sensitivity in the detection of knee osteoarthritis and poor correlation with pain and physical function. 3D joint space width, measured from weight bearing CT images, may yield a more accurate correlation with patients' symptoms. We assessed the cross-sectional association between 3D joint space width and self-reported pain and physical function. 528 knees (57% women) were analyzed from Multicenter Osteoarthritis Study participants. An upright weight bearing CT scanner was used to acquire bilateral, weight-bearing fixed-flexion images of the knees. A 3D dataset was reconstructed from cone beam projections and joint space width was calculated across the joint surface. The percentages of the apposed medial tibiofemoral joint surface with joint space width <2.0mm and <2.5mm respectively were calculated. Pain and physical function were measured using Western Ontario and McMaster Universities Osteoarthritis Index. Participants who reported greater pain severity tended to have a greater joint area with joint space width <2.0mm (p=.07 for the highest vs. the lowest tertile). Participants who reported greater functional limitations had a greater joint area with joint space width <2.0mm (p=.02 for the highest vs. the lowest tertile). There appears to be an association between the medial tibiofemoral area with joint space width <2.0mm and pain and physical function. This article is protected by copyright. All rights reserved.

Longitudinal MRI structural findings observed in accelerated knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

To analyze structural, longitudinal MRI findings during the development of accelerated knee osteoarthritis (AKOA) over 4 years.

MATERIALS AND METHODS

From the Osteoarthritis Initiative (OAI), knees with no radiographic osteoarthritis (KL 0/1) developing advanced-stage osteoarthritis (KL 3/4; AKOA) within a 4-year (y) timeframe were selected. MRIs were graded using the modified Whole-Organ Magnetic Resonance Imaging Score (WORMS) at the beginning of the 4-year timeframe (index visit), at 2-year, and 4-year follow-up. Morphological and clinical findings associated with KL 3/4 onset within 2 years compared to 4 years were assessed using generalized estimating equations.

RESULTS

AKOA was found in 162 knees of 149 subjects (age 63.25 ± 8.3; 103 females; BMI 29.4 ± 3.9). Moderate to severe meniscal lesions WORMS ≥ 3 were present in 25% (41/162) at the index visit, 64% (104/162) at 2-year and 93% (151/162) at 4-year follow-up. Meniscal extrusion was the most prevalent finding (ranging from 18% at the index visit, 45% at 2-year and 94% at 4-year follow-up) and root tears were the most common types of tears (9% at the index visit; 22% at 2 years and 38% at 4 years). Risk factors associated with KL 3/4 onset within 2 years included root tears at the index visit (adjusted OR, 2.82; 95% CI: 1.33, 6.00; p = 0.007) and incident knee injury (42%, 49/116 vs. 24%, 11/46, p = 0.032).

CONCLUSIONS

Meniscal abnormalities, in particular extrusion and root tears, were the most prevalent morphological features found in subjects with AKOA. These results suggest that meniscal abnormalities have a significant role in accelerated progression of OA.

Knee osteoarthritis risk in non-industrial societies undergoing an energy balance transition: evidence from the indigenous Tarahumara of Mexico

Non-industrial societies with low energy balance levels are expected to be less vulnerable than industrial societies to diseases associated with obesity including knee osteoarthritis. However, as non-industrial societies undergo rapid lifestyle changes that promote positive energy balance, individuals whose metabolisms are adapted to energetic scarcity are encountering greater energy abundance, increasing their propensity to accumulate abdominal adipose tissue and thus potentially their sensitivity to obesity-related diseases.

OBJECTIVES

Here, we propose that knee osteoarthritis is one such disease for which susceptibility is amplified by this energy balance transition.

METHODS

Support for our hypothesis comes from comparisons of knee radiographs, knee pain and anthropometry among men aged ≥40 years in two populations: Tarahumara subsistence farmers in Mexico undergoing the energy balance transition and urban Americans from Framingham, Massachusetts.

RESULTS

We show that despite having markedly lower obesity levels than the Americans, the Tarahumara appear predisposed to accrue greater abdominal adiposity (ie, larger abdomens) for a given body weight, and are more vulnerable to radiographic and symptomatic knee osteoarthritis at lower levels of body mass index. Also, proportionate increases in abdomen size in the two groups are associated with greater increases in radiographic knee osteoarthritis risk among the Tarahumara than the Americans, implying that the abdominal adipose tissue of the Tarahumara is a more potent stimulus for knee degeneration.

CONCLUSIONS

Heightened vulnerability to knee osteoarthritis among non-industrial societies experiencing rapid lifestyle changes is a concern that warrants further investigation since such groups represent a large but understudied fraction of the global population.

One Hour a Week: Moving to Prevent Disability in Adults With Lower Extremity Joint Symptoms

INTRODUCTION

Physical activity guidelines recommend minimum thresholds. This study sought to identify evidence-based thresholds to maintain disability-free status over 4years among adults with lower extremity joint symptoms.

METHODS

Prospective multisite Osteoarthritis Initiative accelerometer monitoring cohort data from September 2008 through December 2014 were analyzed. Adults (n=1,564) aged ≥49years at elevated disability risk because of lower extremity joint symptoms were analyzed for biennial assessments of disability-free status from gait speed ≥1meter/second (mobility disability-free) and self-report of no limitations in activities of daily living (activities of daily living disability-free). Classification tree analyses conducted in 2017-2018 identified optimal thresholds across candidate activity intensities (sedentary, light, moderate-vigorous, total light and moderate-vigorous activity, and moderate-vigorous accrued in bouts lasting ≥10 minutes).

RESULTS

Minimal thresholds of 56 and 55 moderate-vigorous minutes/week best predicted disability-free status over 4years from mobility and activities of daily living disabilities, respectively, across the candidate measures. Thresholds were consistent across sex, BMI, age, and knee osteoarthritis presence. Mobility disability onset was one eighth as frequent (3% vs 24%, RR=0.14, 95% CI=0.09, 0.20) and activities of daily living disability onset was almost half (12% vs 23%, RR=0.55, 95% CI=0.44, 0.70) among people above versus below the minimum threshold.

CONCLUSIONS

Attaining an evidence-based threshold of approximately 1-hour moderate-vigorous activity/week significantly increased the likelihood of maintaining disability-free status over 4years. This minimum threshold tied to maintaining independent living abilities has value as an intermediate goal to motivate adults to take action towards the many health benefits of a physically active lifestyle.

Validation of a new symptom outcome for knee osteoarthritis: the Ambulation Adjusted Score for Knee pain

OBJECTIVE

Validation of a symptom measure for early knee OA may help identify new treatments and modifiable risk factors. Symptom measures that consider pain in the context of activity level may provide better discrimination than pain alone. Therefore, we aimed to compare sensitivity to change for radiographic progression between Ambulation Adjusted Score for Knee pain (AASK), which accounts for self-reported ambulation, and Western Ontario McMaster Osteoarthritis (WOMAC) knee pain score.

DESIGN

Participants were assessed annually up to 48 months using WOMAC, Physical Activity Scale for the Elderly (PASE) ambulation, and knee radiographs. AASK was defined as ((WOMAC pain) + 1)/((average daily hours of walking) + 1). Radiographs were scored for Kellgren-Lawrence (KL) grade. Linear regression, stratified by OA status, evaluated relationships between changes in AASK and WOMAC pain and KL grade over time.

RESULTS

For 4191 people (8030 knees), the mean age was 61.2 (+ 9.2) years old and BMI was 28.6 (+ 4.8) kg/m2; 58% female. Over 40% of knees had WOMAC pain scores of 0; by design, no knees had AASK scores of 0. Annual changes in AASK were more sensitive to changes in KL than changes in WOMAC in those without baseline OA (0.20 and 0.16 change per unit KL change, p = 0.005 and 0.070 respectively), but performed similarly in knees with OA.

CONCLUSION

AASK is simple to assess using existing validated questionnaires. AASK performs well in individuals with and without OA and should be considered in clinical trials and observational studies of early knee OA.

Reallocating time spent in sleep, sedentary behavior and physical activity and its association with pain: a pilot sleep study from the Osteoarthritis Initiative

OBJECTIVE

Being physically active has broad health benefits for people with osteoarthritis (OA), including pain relief. Increasing physical activity (PA) requires reducing time in other behaviors within a fixed 24-h day. We examined the potential benefits in relation to pain from trading time in one type of wake or sleep behavior for another.

METHOD

In this cross-sectional study, we used isotemporal logistic regression models to examine the estimated effect on pain from replacing time in one behavior with equal time in another, controlling for sociodemographic and health factors. Stratified analysis was conducted by the report of restless sleep. Sleep and wake behaviors [sedentary behavior (SB), light PA, moderate PA] were monitored by accelerometer in a pilot study of 185 Osteoarthritis Initiative (OAI) participants. Outcomes were bodily pain interference and knee pain.

RESULTS

Moderate PA substituted for an equivalent time in sleep or other types of wake behaviors was most strongly associated with lower odds of pain (bodily pain interference odds reduced 21-25%, knee pain odds reduced 17-20% per 10-min exchange). These beneficial associations were particularly pronounced in individuals without restless sleep, but not in those with restless sleep, especially for bodily pain interference.

CONCLUSION

Interventions promoting moderate physical activities may be most beneficial to address pain among people with or at high risk for knee OA. In addition to encouraging moderate-intensity PA, pain management strategies may also include the identification and treatment of sleep problems.

Signal intensity alteration within infrapatellar fat pad predicts knee replacement within 5 years: data from the Osteoarthritis Initiative

OBJECTIVE

To investigate whether infrapatellar fat pad (IPFP) signal intensity (SI) alteration predicts the occurrence of knee replacement (KR) in knee osteoarthritis (OA) patients over 5 years.

DESIGN

The subjects were selected from Osteoarthritis Initiative (OAI) study. Case knees (n = 127) were defined as those who received KR during 5 years follow-up visit. They were matched by gender, age and radiographic status with control knees (n = 127). We used T2-weighted MR images to measure IPFP SI alteration using a newly developed algorithm in MATLAB. The measurements were assessed at baseline (BL), T0 (the visit just before KR) and 1 year before T0 (T-1). Conditional logistic regression was used to analyse the associations between IPFP SI alterations and the risk of KR.

RESULTS

Participants were mostly female (57%), with an average age of 63.7 years old and a mean body mass index (BMI) of 29.5 kg/m2. In multivariable analysis, the standard deviation (SD) of IPFP SI [sDev (IPFP)] and the ratio of high SI region volume to whole IPFP volume [Percentage (H)] measured at BL were significantly associated with increased risks of KR after adjustment for covariates. IPFP SI alterations measured at T-1 including sDev (IPFP), Percentage (H) and clustering effect of high SI [Clustering factor (H)] were significantly associated with higher risks of KR. All measurements were significantly associated with higher risks of KR at T0.

CONCLUSIONS

IPFP SI is associated with the occurrence of KR suggesting it may play a role in end-stage knee OA.

Quantitative measurement of cartilage volume is possible using two-dimensional magnetic resonance imaging data sets

PURPOSE

3D Magnetic resonance imaging (MRI) scans are generally used for quantitative cartilage measurements in knee osteoarthritis. However, a great deal of MRI data is from 2D scans, often thought to be unsuitable for quantitative cartilage assessment. The goal of our study was to demonstrate that mLACS, a modified version of the Local Area Cartilage Segmentation (LACS) method, could be used to measure cartilage volume on 2D MRI images.

METHODS

We studied 301 randomly selected subjects from the OA Biomarkers Consortium FNIH Study, a nested case-control study within the Osteoarthritis Initiative (OAI). The study comprised four subgroups based on radiographic and pain progression. We compared mLACS applied to 2D TSE scans to LACS on 3D DESS data. The Pearson's correlation coefficient was used to establish agreement between LACS and mLACS, standardized response means (SRMs) for responsiveness, and intra-class correlation coefficients (ICCs) to measure reader precision. Logistic regression in a case/control analysis was used to compare the clinical validity between the two methods.

RESULTS

We found R² = 0.76 for the correlation between LACS and mLACs. For LACS, the responsiveness was SRM = 0.49 compared to 0.39 for mLACS. The odds ratios (OR) for the primary case/control analyses were 1.62 for LACS and 1.78 for mLACS. The intra and inter reader reproducibility values for mLACS were ICC = 0.90 and 0.86, respectively.

CONCLUSION

This study has demonstrated that a reproducible, responsive, and clinically valid quantitative measurement of cartilage volume can be made using 2D TSE scans with a modest loss of responsiveness compared to 3D scans.

Patients Less Likely to Lose Weight Following a Knee Replacement: Results From the Osteoarthritis Initiative

BACKGROUND

Knee replacement typically results in reduced pain and improved function, but it is unclear if these improvements lead to weight loss.

OBJECTIVE

The purpose of this study was to examine weight change patterns preoperatively and postoperatively among overweight/obese knee replacement patients.

METHODS

The study evaluated 210 overweight/obese patients from the Osteoarthritis Initiative who underwent a knee replacement during an 8-year longitudinal study. Average annual weight changes during 1- to 2-year intervals prior to, including, and subsequent to knee replacement were categorized as loss (≥-2.5%), maintain (>-2.5% to <2.5%), and gain (≥2.5%). Weight changes across time intervals were compared using logistic regression with generalized estimating equations, adjusting for demographic, health, and knee factors.

RESULTS

On average, patients lost -0.6 kg/y during the interval when the surgery was performed, but weight gain (0.9 kg/y) in the initial postoperative interval represented an overall net weight gain (0.3 kg/y) compared with presurgery. Continued weight gain (0.3 kg/y) was also seen among patients with additional follow-ups. Patients were significantly less likely to have a meaningful weight loss in the time interval immediately following the surgery compared with the interval in which the surgery took place (odds ratio, 0.37; 95% confidence interval, 0.18-0.79).

CONCLUSIONS

Overweight and obese patients initially lost weight during the interval including knee replacement; however, they were less likely to lose more than 2.5% of their weight in the 1 to 2 years immediately after the surgery. Knee replacement patients may benefit from weight management interventions both preoperatively and postoperatively.

The posterior-anterior flexed view is better than the anterior-posterior view for assessing osteoarthritis of the knee

OBJECTIVE

The aim of this study is to determine whether the posterior-anterior (PA)-flexed view improves the radiographic assessment of patients with knee pain compared with the standard standing anterior-posterior radiograph.

MATERIALS AND METHODS

Three hundred and sixty-five patients with knee pain underwent anterior-posterior (AP), PA flexed, lateral, and Merchant radiographs of the knee. Knees were grouped as mild (Kellgren and Lawrence [K-L] 1-2) or severe (K-L 3-4) osteoarthritis (OA) and either varus (medial compartment), valgus (lateral compartment), or patellofemoral OA.

RESULTS

In knees with mild valgus OA on AP view (K-L 1-2), the PA flexed view was more sensitive than the AP view. The measured lateral minimal joint space width (minJSW) decreased more than 2 mm in 68% of the patients, resulting in an increase in K-L grade (3 or 4). In patients with severe valgus OA and in all patients with varus and patellofemoral OA, there was no difference between AP and PA flexed view with regard to radiographic measurements or KL grade. Based on the Medicare reimbursement rate using the PA flexed view alone instead of both views reduced imaging costs by 47%.

CONCLUSION

The PA flexed view better classifies the severity of lateral compartment disease in patients with mild valgus OA and provides comparable diagnostic sensitivity for joint space narrowing in varus- and patellofemoral OA. Using the PA flexed view alone was more cost effective than using the combination of AP and PA flexed imaging.

Association of Mucoid Degeneration of the Anterior Cruciate Ligament at MR Imaging with Medial Tibiofemoral Osteoarthritis Progression at Radiography: Data from the Osteoarthritis Initiative

Purpose To determine whether anterior cruciate ligament (ACL) mucoid degeneration in participants with or at risk for osteoarthritis is associated with longitudinal risk of radiographic progression of medial tibiofemoral compartment joint space loss (JSL). Materials and Methods Baseline demographic, clinical, radiographic, and Magnetic Resonance (MR) Imaging Osteoarthritis Knee Score (MOAKS) data were evaluated in 600 participants from the Osteoarthritis Initiative database. Two blinded musculoskeletal radiologists independently evaluated baseline MR images for ACL mucoid degeneration. Multiple logistic regression was used to investigate the association between ACL mucoid degeneration at MR imaging and JSL progression at radiography, defined as a minimum joint space width decrease greater than 0.7 mm (48 months; cutoff according to mean and standard deviation of 1-year minimum joint space width changes in 90 knees of reference group). Stratified analysis was performed based on baseline cartilage surface damage. Results Knees with ACL mucoid degeneration showed a greater proportion of JSL progression compared with knees with a normal ACL (64% vs 47%; P = .004). After adjustment for all demographic, clinical, radiographic, and MOAKS variables, ACL mucoid degeneration was not statistically significantly associated with JSL progression in the entire cohort (adjusted odds ratio, 1.66; 95% confidence interval: 1.00, 2.77; P = .051). In subgroup analysis, ACL mucoid degeneration was statistically significantly associated with JSL progression in participants with less baseline cartilage surface damage (maximum cartilage surface loss of ≤75% in all subregions [P = .015] and ≤4 of involved subregions with cartilage surface loss [P = .028]). Conclusion ACL mucoid degeneration in participants with or at risk for osteoarthritis is associated with progression of medial tibiofemoral compartment JSL in knees with less baseline cartilage surface area damage. ^© RSNA, 2018 Online supplemental material is available for this article.

Predictive Validity of Radiographic Trabecular Bone Texture in Knee Osteoarthritis: The Osteoarthritis Research Society International/Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium

OBJECTIVE

To evaluate radiographic subchondral trabecular bone texture (TBT) as a predictor of clinically relevant osteoarthritis (OA) progression (combination of symptom and structural worsening).

METHODS

The Foundation for the National Institutes of Health (FNIH) OA Biomarkers Consortium undertook a study of progressive knee OA cases (n = 194 knees with both radiographic and pain progression over 24-48 months) and comparators (n = 406 OA knees not meeting the case definition). TBT parameters were extracted from a medial subchondral tibial region of interest by fractal signature analysis of radiographs using validated semiautomated software. Baseline TBT and time-integrated values over 12 and 24 months were evaluated for association with case status and separately with radiographic and pain progression status, adjusted for age, sex, body mass index, race, baseline Kellgren/Lawrence grade, baseline joint space width, Western Ontario and McMaster Universities Osteoarthritis Index pain score, and pain medication use. C statistics were generated from receiver operating characteristic curves.

RESULTS

Relative to comparators, cases were characterized by thinner vertical and thicker horizontal trabeculae. The summed composite of 3 TBT parameters at baseline and over 12 and 24 months best predicted case status (odds ratios 1.24-1.43). The C statistic for predicting case status using the TBT composite score (0.633-0.649) was improved modestly but statistically significantly over the use of covariates alone (0.608). One TBT parameter, reflecting thickened horizontal trabeculae in cases, at baseline and over 12 and 24 months, predicted risk of any progression (radiographic and/or pain progression).

CONCLUSION

Although associations are modest, TBT could be an attractive means of enriching OA trials for progressors since it can be generated from screening knee radiographs already standard in knee OA clinical trials.

Subjective Crepitus as a Risk Factor for Incident Symptomatic Knee Osteoarthritis: Data From the Osteoarthritis Initiative

OBJECTIVE

Subjective crepitus is the reporting of hearing grating, cracking, or popping sounds in and/or around a joint. We aimed to evaluate whether there is an association between crepitus and incident symptomatic knee osteoarthritis (OA) in the Osteoarthritis Initiative (OAI), a multicenter longitudinal US cohort.

METHODS

Knees without baseline symptomatic OA were included. Crepitus frequency was assessed using a question from the Knee Injury and Osteoarthritis Outcome Score at baseline and at 12, 24, and 36 months. Frequent knee pain and radiographs were assessed at baseline and at annual visits up to 48 months. Radiographic OA was defined as a tibiofemoral Kellgren/Lawrence grade ≥2. Symptomatic OA was defined as a knee with both frequent symptoms and radiographic OA. We performed a repeated-measures analysis with a predictor of crepitus and outcome of incident symptomatic OA, adjusting for age, sex, and body mass index (BMI), with those never reporting crepitus as the referent group.

RESULTS

There were a total of 3,495 participants (42.2% male), with mean ± SD age of 61.1 ± 9.2 years and a mean ± SD BMI of 28.2 ± 4.7 kg/m². The odds of incident symptomatic OA were higher with greater frequency of crepitus (never, rarely, sometimes, often, and always, with adjusted odds ratios of (referent), 1.5, 1.8, 2.2, and 3.0, respectively; P < 0.0001 for trend). The group with radiographic OA at OAI baseline but without symptoms contributed 26% of the observations but more than 75% of the incident symptomatic OA cases.

CONCLUSION

In those without symptomatic OA, subjective knee crepitus predicts incident symptomatic OA longitudinally, with most cases occurring in those with preexisting tibiofemoral radiographic OA but without frequent knee pain. However, an important limitation is that patellofemoral OA was not systematically evaluated within the OAI. Subjective crepitus offers utility for the identification of at-risk individuals, predictive modeling, and future research.

Fixed-flexion view X-ray of the knee superior in detection and follow-up of knee osteoarthritis

A fixed flexion view (FFV) is useful for evaluating joint space when assessing the severity of osteoarthritis (OA) of the knee. We analyzed changes in joint space revealed by standing extended view (SEV) and FFV over a mean 4 years, to compare both views on their capacity to measure joint space width accurately at particular time points during follow-up.SEV and FFV images were acquired in patients with knee OA. The 81 patients (157 knees) followed up for ≥24 months were selected as study subjects. Medial joint space widths (MJSW), Kellgren-Lawrence (KL) grades, and reductions in MJSW on SEV (ΔSEV) and FFV (ΔFFV) were compared in knees evaluated by SEV and FFV.At both time-points, mean MJSW was significantly lower by FFV than by SEV. Mean MJSW was significantly lower at follow-up than at first examination by both SEV and FFV. At both time-points, the KL grade was higher by FFV than by SEV group. The ΔFFV was significantly greater than the ΔSEV. ΔSEV did not differ significantly among KL grades, but ΔFFV was significantly greater in patients with KL grade II than in patients with other KL grades.FFV is not only useful for evaluating joint space in knees with OA, but also for accurately evaluating the progression of OA. The risk of rapid progression of knee OA may be higher in patients with KL grade II, as determined by FFV. FFV may be superior to SEV in determining appropriate treatment strategies for knee OA.

Potential Functional Benefit From Light Intensity Physical Activity in Knee Osteoarthritis

INTRODUCTION

Knee pain may preclude participation in higher intensity physical activity in people with knee osteoarthritis and benefits of light activity are unclear. The effect of replacing sedentary time with light intensity activity on incident functional limitation 2 years later was investigated.

METHODS

Included were people with or at high risk of knee osteoarthritis without baseline functional limitation using data from the Osteoarthritis Initiative collected between August 2008 and July 2010. Data were analyzed between May 2016 and August 2016 for time in sedentary, light, and moderate to vigorous physical activity from accelerometer monitoring. Incident functional limitation was defined as (1) slow gait speed <1.0 meters/second during a 20-meter walk, (2) Western Ontario and McMasters University Osteoarthritis Index physical function ≥28, or (3) Short Form 12 Physical Component scale <40.

RESULTS

Inclusion criteria were met by 1,873 people (mean age=65.0 [SD=9.0] years, mean BMI=28.4 [SD=4.7] kg/m²). Replacing 60 minutes/day of sedentary time with 60 minutes/day of light activity was associated with a 17% reduced risk for incident slow gait speed 2 years later (Hazard Ratio=0.83, 95% CI=0.70, 0.99) after adjustment. Approximately 5 minutes/day of moderate to vigorous physical activity would be necessary to receive the equivalent benefit of 60 minutes/day of light activity. Effects in secondary patient-reported outcomes did not reach statistical significance.

CONCLUSIONS

Replacing sedentary time with light activity may reduce the risk of performance-based functional limitation. As expected, moderate to vigorous physical activity rather than light provided stronger risk reduction. When moderate to vigorous physical activity is not an option, pursuing light activity may be a beneficial alternative to being sedentary.

Relationship of knee pain to time in moderate and light physical activities: Data from Osteoarthritis Initiative

INTRODUCTION

While OA literature indicates greater pain is related to less time being physically active, it is not known if time curtailment occurs primarily for moderate intensity activities or for light activities or in both. We examine the cross-sectional association of knee pain with physical activity using data from 1874 Osteoarthritis Initiative participants.

METHODS

Knee pain characteristics of constant and intermittent pain were each scored by the Intermittent and Constant Osteoarthritis Pain instrument and categorized into four pain levels (no pain, intermittent pain below and above median level, and constant pain). The relationships between knee pain levels and objectively measured physical activity (average weekly moderate or light intensity minutes) were assessed by quantile regression adjusted for socio-demographics and health factors.

RESULTS

Knee pain levels had a strong negative relationship with moderate intensity physical activities (p-value for trend =0.029). Compared to the no pain group, persons with more severe knee pain, particularly those reporting higher intermittent or constant pain spent less time in moderate activity. In contrast, there was no notable trend related to pain with time spent in light intensity activity. These patterns remained when restricted to persons with clinical evidence (symptoms and/or radiographic) of knee OA and among persons not using medications for knee symptoms.

CONCLUSION

Greater knee pain levels were strongly related to less moderate intensity activity time, but not time spent in light intensity physical activity. This relationship suggests that light activity may be a more acceptable way to increase physical activity than moderate activity for people with symptomatic knee pain.

[Chondral and osteochondral defects : Representation by imaging methods]

Morphological imaging of cartilage at high resolution allows the differentiation of chondral and osteochondral lesions. Nowadays, magnetic resonance imaging is the principal diagnostic tool in the assessment of cartilage structure and composition. Conventional radiography, computed tomography, ultrasound or optical coherence tomography are adjunct diagnostic modalities in the assessment of cartilage pathologies. The present article discusses the up-to-date diagnostic practice of cartilage imaging in terms of its scientific basis and current clinical status, requirements, techniques and image interpretation. Innovations in the field such as functional MRI are discussed as well due to their mid- to long-term clinical perspective.

Race, sex, and risk factors in radiographic worsening of knee osteoarthritis

OBJECTIVES

Characterize radiographic worsening in knee osteoarthritis (KOA) by race and sex over 4 years and evaluate the role of established risk factors in observed race/sex differences.

METHODS

Whites (WHs) (694 males and 929 females) and African-Americans (AAs) (92 males and 167 females) at risk for radiographic KOA were eligible. Cox shared frailty models were used to estimate race and sex group differences in radiographic worsening, defined by Kellgren-Lawrence (K-L) and OARSI joint space narrowing (JSN). Mixed effect models for repeated measures were used to estimate race- and sex-specific mean medial and lateral fixed joint space width (fJSW) over 4 years of follow-up, as well as annual loss of fJSW.

RESULTS

Risk of OARSI medial JSN grade worsening was higher among AA males than WH females [HR = 2.28, (95% CI: 1.14-4.57)], though adjustment for KOA risk factors attenuated the association. Compared to WH females, WH males had lower risk of K-L grade worsening [adjusted HR = 0.75 (95% CI: 0.58-0.96)]. Mean baseline medial fJSW (mm) was 6.49 in WH and AA males, 5.42 in WH females, and 5.41 in AA females. Annual change in mean medial fJSW was greater in AA males (-0.19mm/year) than in other subgroups (-0.09 WH males, -0.07 WH females, -0.10 AA females, p < 0.0001). Compared to WHs, AAs had less lateral fJSW at baseline and throughout follow-up.

CONCLUSIONS

Compared to WHs and AA females, AA males experienced higher risk of medial joint space loss. Controlling for established risk factors attenuated associations between race/sex and disease worsening, suggesting that risk factors such as obesity, history of knee injury, and bony finger joint enlargements largely explain race/sex variations in rates of KOA development and progression.

Association of Slow Gait Speed With Trajectories of Worsening Depressive Symptoms in Knee Osteoarthritis: An Observational Study

OBJECTIVE

To investigate the association of slow gait speed, defined as walking slower than is necessary for the community, with trajectories of depressive symptoms over 7 years among people with or at high risk of knee OA.

METHODS

Using data from the Osteoarthritis Initiative, we described trajectories of depressive symptoms measured annually with the Center for Epidemiologic Studies Depression Scale. We categorized speed during a 20-meter walk of <1.2 meters/second as slow gait speed. We used a group-based method to agnostically identify homogeneous clusters of depressive symptom trajectories. We then examined the association of slow gait speed with depressive symptom trajectories, using multinomial logistic regression adjusted for potential confounders.

RESULTS

From the 3,939 participants included (mean ± SD age 61.4 ± 9.2 years, body mass index 28.4 ± 4.7, 58% women, and 63% with a college degree), we identified 5 trajectories. The first 3 were stable over time and included 74% of the sample. The remainder had worsening depressive symptoms over time. Slow gait speed was associated with 2.1 times the odds of having the worst depressive symptoms trajectory compared to those without slow gait speed.

CONCLUSION

Slow gait speed may represent an important risk factor for worsening depressive symptoms over time in people with or at high risk of knee OA, and may signal the need for rehabilitation.