Frequent Knee Pain Research Articles

Changes in thigh muscle strength prior to and concurrent with incident knee pain – data from the osteoarthritis initiative

Changes in thigh muscle strength prior to and concurrent with incident knee pain – data from the osteoarthritis initiative

Relationship Between Knee Pain and Infrapatellar Fat Pad Morphology: A Within- and Between-Person Analysis From the Osteoarthritis Initiative.

Inflammation is known to be strongly associated with knee pain in osteoarthritis. The infrapatellar fat pad represents a potential source of proinflammatory cytokines. Yet the relationship between infrapatellar fat pad morphology and osteoarthritis symptoms is unclear. Here we investigate quantitative imaging parameters of infrapatellar fat pad morphology between painful versus contralateral pain-free legs of subjects with unilateral knee pain and patients with chronic knee pain versus those of matched pain-free control subjects. A total of 46 subjects with strictly unilateral frequent knee pain and bilateral radiographic osteoarthritis (Kellgren/Lawrence grade 2/3) were drawn from the Osteoarthritis Initiative. Further, 43 subjects with chronic knee pain over 4 years and 43 matched pain-free controls without pain over this period were studied. Infrapatellar fat pad morphology (volume, surface area, and depth) was determined by manual segmentation of sagittal magnetic resonance images. No significant differences in infrapatellar fat pad morphology were observed between painful versus painless knees of persons with strictly unilateral knee pain (mean difference -0.7% (95% confidence interval [95% CI] -0.6, 0.9; P = 0.64) or between chronically painful knees versus matched painless controls (-2.1% [95% CI -2.2, 1.1]; P = 0.51). Independent of the ambiguous role of the infrapatellar fat pad in knee osteoarthritis (a potential source of proinflammatory cytokines or a mechanical shock absorber), the size of the infrapatellar fat pad does not appear to be related to knee pain.

Radiographic Knee Osteoarthritis and Knee Pain: Cross-sectional study from Five Different Racial/Ethnic Populations

The weak correlation between pain and structural changes in knee osteoarthritis is widely reported. In a previous within-person, knee-matched case-control study among Caucasians, the severity of radiographic osteoarthritis (ROA) was strongly associated with both the presence of frequent knee pain and pain severity. We studied the association between ROA and knee pain in five racial/ethnic populations by using the same method. Subjects were selected from China; Japan; Korea and the United States. Among subjects with knees discordant for either frequent knee pain or pain severity, we examined the relationship between ROA and the presence of frequent knee pain using conditional logistic regression, and between ROA and pain severity using a stratified proportional odds model with an amalgamating conditional likelihood. In total, 252 urban Chinese, 221 rural Chinese, 297 Japanese, 122 Korean, 1,735 Caucasian, and 394 African-American patients were included. There was a strong dose-response relationship between the severity of ROA and the prevalence of frequent knee pain in all five racial/ethnic populations. Even mild ROA was significantly associated with frequent knee pain. In addition, ROA was also strongly associated with the severity of knee pain. These results show that structural pathology is associated with knee pain in different ethnic populations.

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

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. 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. 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. 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.

Middle-aged patients with an MRI-verified medial meniscal tear report symptoms commonly associated with knee osteoarthritis

Background and purpose — No consensus exists on when to perform arthroscopic partial meniscectomy in patients with a degenerative meniscal tear. Since MRI and clinical tests are not accurate in detecting a symptomatic meniscal lesion, the patient’s symptoms often play a large role when deciding when to perform surgery. We determined the prevalence and severity of self-reported knee symptoms in patients eligible for arthroscopic partial meniscectomy due to a degenerative meniscal tear. We investigated whether symptoms commonly considered to be related to meniscus injury were associated with early radiographic signs of knee osteoarthritis.Patients and methods — We included individual baseline items from the Knee injury and Osteoarthritis Outcome Score collected in 2 randomized controlled trials evaluating treatment for an MRI-verified degenerative medial meniscal tears in 199 patients aged 35–65 years. Each item was scored as no, mild, moderate, severe, extreme, and at least “mild” considering the symptoms present. Early radiographic signs of osteoarthritis, defined as a Kellgren and Lawrence grade of at least 1, were seen in 70 patients.Results — At least monthly knee pain, pain during stair walking and when twisting on the knee, and lack of confidence in knee was present in at least 80% of the patients. Median severity was at least moderate for knee pain, pain when twisting on the knee, pain walking on stairs, lack of confidence in knee, and clicking. Mechanical symptoms such as catching were rare. Early radiographic signs of osteoarthritis were associated with an increased risk of self-reported swelling, catching, and stiffness later in the day; the odds ratio was 2.4 (95% CI 1.2–4.9), 2.3 (1.2–4.3), and 2.3 (1.1–5.0), respectively.Interpretation — Middle-aged patients with a degenerative medial meniscus tear reported symptoms commonly associated with knee osteoarthritis. Frequent knee pain, presence of lack of confidence in the knee, and clicking did not distinguish those with a meniscal tear alone from those with early radiographic knee OA. Our findings support the notion that symptoms reported by those with a degenerative meniscal tear represent early signs of knee osteoarthritis.

Knee Pain and Structural Damage as Risk Factors for Incident Widespread Pain: Data From the Multicenter Osteoarthritis Study.

To examine the longitudinal relationship of knee pain, radiographic osteoarthritis (OA), symptomatic knee OA, and knee pain severity to incident widespread pain. The Multicenter Osteoarthritis Study is a longitudinal cohort of persons with or at risk of knee OA. Participants were characterized as having consistent frequent knee pain, radiographic OA (Kellgren/Lawrence scale grade ≥2), symptomatic OA, and knee pain severity at the 60-month visit (baseline). Widespread pain was categorized as pain above and below the waist, on both sides of the body and axially, using a standard homunculus, excluding knee pain. Incident widespread pain was defined as the presence of widespread pain at 84 months in those who were free of widespread pain at baseline. We assessed the relationship of baseline radiographic OA, symptomatic OA, consistent frequent knee pain, and knee pain severity, respectively, with incident widespread pain using logistic regression, adjusting for potential confounders, including models with and without pain severity. At baseline, 1,129 subjects were eligible for analysis (mean ± SD age 66.7 ± 7.8 years; mean ± SD body mass index 30.1 ± 5.8 kg/m2 ; 52% women). Radiographic OA in either knee (adjusted odds ratio [ORadj ] 0.90 [95% confidence interval (95% CI) 0.63-1.30]; P = 0.587) was not associated with incident widespread pain. Baseline bilateral consistent frequent knee pain (ORadj 2.35 [95% CI 1.37-4.03]), bilateral symptomatic OA (ORadj 2.11 [95% CI 1.04-4.24]), and knee pain severity (worst knee) (ORadj 1.11 [95% CI 1.05-1.17]; P < 0.001) were significantly associated with incident widespread pain. Consistent frequent knee pain, symptomatic OA, and knee pain severity increased the risk of developing widespread pain, independently of structural pathology. These results suggest that knee pain, and not structural pathology, contributes to the onset of widespread pain.

Incident Frequent Knee Pain is Associated With Incident and Increased Severity of Mri-Detected Structural Pathology in Knee Osteoarthritis

Incident Frequent Knee Pain is Associated With Incident and Increased Severity of Mri-Detected Structural Pathology in Knee Osteoarthritis

Is There an Association Between a History of Running and Symptomatic Knee Osteoarthritis? A Cross-Sectional Study From the Osteoarthritis Initiative.

Regular physical activity, including running, is recommended based on known cardiovascular and mortality benefits. However, controversy exists regarding whether running can be harmful to knees. The purpose of this study is to evaluate the relationship of running with knee pain, radiographic osteoarthritis (OA), and symptomatic OA. This was a retrospective cross-sectional study of Osteoarthritis Initiative participants (2004-2014) with knee radiograph readings, symptom assessments, and completed lifetime physical activity surveys. Using logistic regression, we evaluated the association of history of leisure running with the outcomes of frequent knee pain, radiographic OA, and symptomatic OA. Symptomatic OA required at least 1 knee with both radiographic OA and pain. Of 2,637 participants, 55.8% were female, the mean ± SD age was 64.3 ± 8.9 years, and the mean ± SD body mass index was 28.5 ± 4.9 kg/m2 ; 29.5% of these participants ran at some time in their lives. Unadjusted odds ratios of pain, radiographic OA, and symptomatic OA for those prior runners and current runners compared to those who never ran were 0.83 and 0.71 (P for trend = 0.002), 0.83 and 0.78 (P for trend = 0.01), and 0.81 and 0.64 (P for trend = 0.0006), respectively. Adjusted models were similar, except radiographic OA results were attenuated. There is no increased risk of symptomatic knee OA among self-selected runners compared with nonrunners in a cohort recruited from the community. In those without OA, running does not appear to be detrimental to the knees.

Effect of a Decision Aid on Access to Total Knee Replacement for Black Patients With Osteoarthritis of the Knee

Black patients with advanced osteoarthritis (OA) of the knee are significantly less likely than white patients to undergo surgery. No strategies have been proved to improve access to surgery for black patients with end-stage OA of the knee. To assess whether a decision aid improves access to total knee replacement (TKR) surgery for black patients with OA of the knee. In a randomized clinical trial, 336 eligible participants who self-identified as black and 50 years or older with chronic and frequent knee pain, a Western Ontario McMaster Universities Osteoarthritis Index score of at least 39, and radiographic evidence of OA of the knee were recruited from December 1, 2010, to May 31, 2014, at 3 medical centers. Exclusion criteria were history of major joint replacement, terminal illness, inflammatory arthritis, prosthetic leg, cognitive impairment, lack of a telephone, or contraindications to elective replacement surgery. Data were analyzed on a per-protocol and intention-to-treat (ITT) basis. Access to a decision aid for OA of the knee, a 40-minute video that describes the risks and benefits of TKR surgery. Receipt of TKR surgery within 12 months and/or a recommendation for TKR surgery from an orthopedic surgeon within 6 months after the intervention. Among 336 patients (101 men [30.1%]; 235 women [69.9%]; mean [SD] age, 59.1 [7.2] years) randomized to the intervention or control group, 13 of 168 controls (7.7%) and 25 of 168 intervention patients (14.9%) underwent TKR within 12 months (P = .04). These changes represent a 70% increase in the TKR rate, which increased by 86% (11 of 154 [7.1%] vs 23 of 150 [15.3%]; P = .02) in the per-protocol sample. Twenty-six controls (15.5%) and 34 intervention patients (20.2%) in the ITT analysis received a recommendation for surgery within 6 months (P = .25). The difference in the surgery recommendation rate between the controls (24 of 154 [15.6%]) and the intervention group (31 of 150 [20.7%]) in the per-protocol analysis also was not statistically significant (P = .25). Adjustment for study site yielded similar results: for receipt of TKR at 12 months, adjusted ORs were 2.10 (95% CI, 1.04-4.27) for the ITT analysis and 2.39 (95% CI, 1.12-5.10) for the per-protocol analysis; for recommendation of TKR at 6 months, 1.39 (95% CI, 0.79-2.44) and 1.41 (95% CI, 0.78-2.55). A decision aid increased rates of TKR among black patients. However, rates of recommendation for surgery did not differ significantly. A patient-centered counseling and educational intervention may help to address racial variations in the use of TKR for the management of end-stage OA of the knee. clinicaltrials.gov Identifer: NCT01851785.

Signs of knee osteoarthritis common in 620 patients undergoing arthroscopic surgery for meniscal tear

Background and purpose — Recent evidence has questioned the effect of arthroscopic knee surgery for middle-aged and older patients with degenerative meniscal tears with or without concomitant radiographic knee osteoarthritis (OA). We investigated the prevalence of early or more established knee OA and patients’ characteristics in a cohort of patients undergoing arthroscopic surgery for a meniscal tear.Patients and methods — 641 patients assigned for arthroscopy on suspicion of meniscus tear were consecutively recruited from February 2013 through January 2015. Of these, 620 patients (mean age 49 (18–77) years, 57% men) with full datasets available were included in the present study. Prior to surgery, patients completed questionnaires regarding onset of symptoms, duration of symptoms, and mechanical symptoms along with the knee injury and osteoarthritis outcome score (KOOS). At arthroscopy, the operating surgeon recorded information about meniscal pathology and cartilage damage. Early or more established knee OA was defined as the combination of self-reported frequent knee pain, cartilage damage, and the presence of degenerative meniscal tissue.Results — 43% of patients (269 of 620) had early or more established knee OA. Of these, a large proportion had severe cartilage lesions with almost half having a severe cartilage lesion in at least 1 knee compartment.Interpretation — Based on a definition including frequent knee pain, cartilage damage, and degenerative meniscal tissue, early or more established knee OA was present in 43% of patients undergoing knee arthroscopy for meniscal tear.

Assessing the external validity of algorithms to estimate EQ-5D-3L from the WOMAC.

BackgroundThe use of mapping algorithms have been suggested as a solution to predict health utilities when no preference-based measure is included in the study. However, validity and predictive performance of these algorithms are highly variable and hence assessing the accuracy and validity of algorithms before use them in a new setting is of importance. The aim of the current study was to assess the predictive accuracy of three mapping algorithms to estimate the EQ-5D-3L from the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) among Swedish people with knee disorders. Two of these algorithms developed using ordinary least squares (OLS) models and one developed using mixture model.MethodsThe data from 1078 subjects mean (SD) age 69.4 (7.2) years with frequent knee pain and/or knee osteoarthritis from the Malmö Osteoarthritis study in Sweden were used. The algorithms’ performance was assessed using mean error, mean absolute error, and root mean squared error. Two types of prediction were estimated for mixture model: weighted average (WA), and conditional on estimated component (CEC).ResultsThe overall mean was overpredicted by an OLS model and underpredicted by two other algorithms (P < 0.001). All predictions but the CEC predictions of mixture model had a narrower range than the observed scores (22 to 90 %). All algorithms suffered from overprediction for severe health states and underprediction for mild health states with lesser extent for mixture model. While the mixture model outperformed OLS models at the extremes of the EQ-5D-3D distribution, it underperformed around the center of the distribution.ConclusionsWhile algorithm based on mixture model reflected the distribution of EQ-5D-3L data more accurately compared with OLS models, all algorithms suffered from systematic bias. This calls for caution in applying these mapping algorithms in a new setting particularly in samples with milder knee problems than original sample. Assessing the impact of the choice of these algorithms on cost-effectiveness studies through sensitivity analysis is recommended.Electronic supplementary materialThe online version of this article (doi:10.1186/s12955-016-0547-y) contains supplementary material, which is available to authorized users.

Socioeconomic inequalities in knee pain, knee osteoarthritis, and health-related quality of life: a population-based cohort study in southern Sweden

Objectives: To determine socioeconomic inequalities in frequent knee pain (FKP), knee osteoarthritis (OA), and associated health-related quality of life (HRQoL) in Sweden.Method: In 2007 a postal questionnaire about knee pain was sent to a random sample of 10 000 residents of Malmö, Sweden (7402 individuals responded). Subjects reporting pain with duration ≥ 4 weeks in one or both knees in the past 12 months were classified as having FKP. A random sample of 1527 subjects with and without FKP attended a clinical and radiographic knee examination and responded to generic and disease-specific HRQoL questionnaires. We used the individuals’ level of education and occupation as socioeconomic status (SES) measures, and we calculated the relative index of inequality (RII) using Poisson regression with robust standard errors adjusted for age and gender. We applied weighting to account for a possible selection bias that might arise from non-responses in the study.Results: With education, the RIIs for FKP and knee OA were 0.71 [95% confidence interval (CI) 0.61–0.84] and 0.56 (95% CI 0.34–0.93), respectively. With occupation, the corresponding figures were 0.70 (95% CI 0.60–0.82) and 0.59 (95% CI 0.37–0.94), respectively. There were socioeconomic gradients in HRQoL in favour of people with better SES. RIIs for FKP and HRQoL but not knee OA were essentially similar after additional adjustment for mediators.Conclusions: In Sweden there are socioeconomic gradients related to both FKP and knee OA as well as HRQoL in favour of people with better SES. SES should be taken into account in health resource allocation pertaining to knee-related disorders.

The relation of patellofemoral joint alignment and trochlear morphology to superolateral Hoffa’s fat pad edema: the most study

Purpose: The infrapatellar or Hoffa’s fat pad (HFP) is an intracapsular but extrasynovial fat tissue in the knee joint located inferior to the patella and posterior to the patellar tendon. It is highly innervated and may be a source of knee pain. Impingement of HFP between the lateral femoral condyle and the patellar tendon is hypothesized to cause inflammation/edema in the superolateral region of HFP. This impingement may be a result of patellofemoral joint (PFJ) alignment and abnormal trochlear morphology. Previous studies in young individuals have demonstrated conflicting results as to which measures of PFJ alignment and trochlear morphology are related to superolateral HFP edema. More generalized inflammation/edema in HFP is present in older individuals with knee osteoarthritis (OA). The aim of the current study was to assess whether measures of PFJ alignment and trochlear morphology are related to superolateral HFP edema and if superolateral HFP edema is related to knee pain in older individuals with or at risk for knee OA. Methods: The Multicenter Osteoarthritis (MOST) study is a NIH-funded longitudinal cohort study of older individuals with or at risk for knee OA. For the current cross-sectional study we used data from the 60-month study visit where all eligible subjects had their knee MRI assessed for other structural features of knee OA. Signal changes in three areas (superolateral, infrapatellar and intercondylar) of HFP were assessed on sagittal proton density-weighted fat-suppressed MRI images from 0 to 3 (0 = normal, 1 = mild, 2 = moderate, 3 = severe) by two musculoskeletal radiologists and dichotomized into presence (>1) and absence (=0). PFJ alignment (bisect offset and patellar tilt angle) and trochlear morphology (lateral trochlear inclination, sulcus angle and trochlear angle) were assessed on axial MRI images and divided into quintiles. Subjects were also queried about the presence of frequent knee pain (FKP) defined as pain on most days of the last month. We determined the relation of measures of PFJ alignment and trochlear morphology to the presence of superolateral HFP edema using logistic regression, adjusting for age, sex and body mass index. We additionally determined the relation of superolateral HFD edema to FKP using logistic regression, adjusting for age, sex, body mass index, depressive symptoms, catastrophizing and presence of signal changes in the infrapatellar/intercondylar HFP. Results: To date, 433 knees have been assessed for PFJ alignment, trochlear morphology and superolateral HFP edema. Superolateral HFP edema was present in 63 (17.7%) of knees. Compared with knees in the lowest quartile of bisect offset, those in the highest had 6.4 (2.6, 15.7) times the odds of having superolateral HFP edema. Compared with knees in the lowest quartile of trochlear angle, those in the highest had 2.7 (1.2, 6.3) times the odds of having superolateral HFP edema. There was no relation of other PFJ alignment/trochlear morphology measures to superolateral HFP edema. There was also no relation of superolateral HFP edema to FKP. Conclusions: Knees with the greatest lateral displacement of the patella had the greatest odds of superolateral HFP edema. Treatments that attempt to normalize PFJ alignment may help to reduce the prevalence of superolateral HFP edema.Tabled 1Table. Relation of PFJ alignment and trochlear morphology to superolateral HFP edema% Patella lateral to midline (Bisect Offset)Quartile 1Quartile 2Quartile 3Quartile 4Range33.91–52.5952.6–58.1658.17–64.664.61–92.79# of knees108109109108Superolateral HFP edema%≥16.511.113.828.7Adjusted OR* (95% CI)1.0 (reference)1.9 (0.70, 5.0)2.5 (0.95, 6.4)6.4 (2.6, 15.7)Trochlear Morpholgy (Trochlear Angle)Quartile 1Quartile 2Quartile 3Quartile 4 (flat trochlea)Range−5.32–0.940.95–3.553.56–5.835.84–26.57# of knees108109109108Superolateral HFP edema%≥18.313.814.724.3Adjusted OR* (95% CI)1.0 (reference)1.6 (0.65, 3.8)1.6 (0.67, 3.9)2.7 (1.2, 6.3)∗Adjusted for age, sex and BMI Open table in a new tab ∗Adjusted for age, sex and BMI

Weighted cumulative exposure models helped identify an association between early knee-pain consultations and future knee OA diagnosis

ObjectiveTo establish the association between prior knee-pain consultations and early diagnosis of knee osteoarthritis (OA) by weighted cumulative exposure (WCE) models. Study Design and SettingData were from an electronic health care record (EHR) database (Consultations in Primary Care Archive). WCE functions for modeling the cumulative effect of time-varying knee-pain consultations weighted by recency were derived as a predictive tool in a population-based case-control sample and validated in a prospective cohort sample. Two WCE functions ([i] weighting of the importance of past consultations determined a priori; [ii] flexible spline-based estimation) were comprehensively compared with two simpler models ([iii] time since most recent consultation; total number of past consultations) on model goodness of fit, discrimination, and calibration both in derivation and validation phases. ResultsPeople with the most recent and most frequent knee-pain consultations were more likely to have high WCE scores that were associated with increased risk of knee OA diagnosis both in derivation and validation phases. Better model goodness of fit, discrimination, and calibration were observed for flexible spline-based WCE models. ConclusionWCE functions can be used to model prediagnostic symptoms within routine EHR data and provide novel low-cost predictive tools contributing to early diagnosis.

Relationship between frequent knee pain, obesity, and gait speed in older adults: data from the Osteoarthritis Initiative.

BackgroundKnee pain (KP) causes gait difficulties in older adults and is associated with slow gait speed (GS). Obesity has negative effects on health. GS is an important indicator of health, well-being, and mean life span in older adults and is a strong predictor of future disability and mortality. The relationship between frequent KP, obesity, and GS in older adults remains unclear. Therefore, the present study aimed at examining the relationship between baseline frequent KP and obesity status on GS over time. We hypothesized that frequent KP, obesity, or both would be associated with decreased GS over time.MethodsThe data from the Osteoarthritis Initiative were used for this 6-year longitudinal cohort study. We studied 3,118 adults aged between 45 years and 79 years. We grouped the participants into the following four categories according to KP frequency and obesity status at baseline: 1) no KP and nonobese, 2) frequent KP and nonobese, 3) no KP and obese, and 4) frequent KP and obese. GS measurements were based on a 20 m walking test timed using a stopwatch; testing was performed at baseline and over a 6-year follow-up period. Walk pace (m/sec) was calculated as the average pace over two trials conducted at clinic visits. General linear mixed models were used to examine the relationships between frequent KP, obesity, and GS.ResultsAfter adjusting for all covariates, at baseline, all the nonobese group with frequent KP (β=−0.06, 95% confidence interval [CI]: −0.07 to −0.04), the obese group with no KP (β=−0.07, 95% CI: −0.1 to −0.04), and the obese group with frequent KP (β=−0.08, 95% CI: −0.1 to −0.05) exhibited decreased GS compared with the nonobese and no KP group. However, the associations between frequent KP, obesity, and GS over time were not statistically significant.ConclusionFrequent KP alone, obesity alone, and the combination of frequent KP and obesity were all associated with decreased GS in older adults. These associations did not change in any of the groups longitudinally; as such, the slopes corresponding to the data remained unchanged.

Relationship Between Medial Meniscal Extrusion and Cartilage Loss in Specific Femorotibial Subregions: Data From the Osteoarthritis Initiative.

Medial meniscal extrusion is known to be related to structural progression of knee osteoarthritis. However, it is unclear whether medial meniscal extrusion is more strongly associated with cartilage loss in certain medial femorotibial subregions than in others. Segmentation of the medial tibial and femoral cartilage (baseline; 1-year followup) and the medial meniscus (baseline) was performed in 60 participants with frequent knee pain (mean ± SD ages 61.3 ± 9.2 years, body mass index 31.3 ± 3.9 kg/m(2) ) and with unilateral medial radiographic joint space narrowing (JSN) grades 1-3, using double-echo steady-state magnetic resonance images. Medial meniscal extrusion distance and extrusion area (percentage) between the external meniscal and tibial margin at baseline, and longitudinal medial cartilage loss in 8 anatomic subregions were determined. A significant association (Pearson's correlation coefficient) was seen between medial meniscal extrusion area in JSN knees and cartilage loss over 1 year throughout the entire medial femorotibial compartment. The strongest correlation was with cartilage loss in the external medial tibia (r =-0.34, P < 0.01 in JSN; r =-0.30, P = 0.02 in knees without JSN). Medial meniscal extrusion was associated with subsequent medial cartilage loss. The external medial tibial cartilage may be particularly vulnerable to thinning once the meniscus extrudes and its surface is exposed to direct, nonphysiological, cartilage-to-cartilage contact.

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis.

IntroductionBone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA.MethodsA search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring.ResultsIn total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively.ConclusionSubchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target.Systematic reviewPROSPERO registration number: CRD 42013005009Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-015-0735-x) contains supplementary material, which is available to authorized users.

Longitudinal impact of frequent knee and back pain on health-related quality of life: data from the osteoarthritis initiative

Longitudinal impact of frequent knee and back pain on health-related quality of life: data from the osteoarthritis initiative

Infra-patellar fat pad morphology and MRI signal distribution in advanced radiographic knee OA – Data from the OAI

s / Osteoarthritis and Cartilage 23 (2015) A82eA416 A219 349 INFRA-PATELLAR FAT PAD MORPHOLOGY AND MRI SIGNAL DISTRIBUTION IN ADVANCED RADIOGRAPHIC KNEE OA e DATA FROM THE OAI F. Eckstein yz, J. Diepold y, A. Ruhdorfer y, T. Dannhauer yz, W. Wirth yz, A. Guermazi xk. y Paracelsus Med. Univ., Salzburg & Nuremberg, Austria; zChondrometrics GmbH, Ainring, Germany; xBoston Univ. Sch. of Med., Boston, MA, USA; kBoston Imaging Core Lab, Boston, MA, USA Purpose: Recent studies suggest that obesity-related risk of knee OA is not fully explained by mechanical challenge, i.e. increased body weight. Yet, adipokines (e.g. leptin) secreted from fat tissue appear to cause lowgrade inflammation, and to contribute to the release of metallo-proteinases and growth factors, which are known to promote cartilage loss and osteophyte formation. The infra-patellar fat pad (IPFP) is unique in representing intra-articular adipose tissue, and is a source of intraarticular leptin. Only few studies, however, have studied the role of the IPFP in human knee OA. Here we explore whether quantitative imaging measures of IPFP size and MRI signal differ between painful knees with and without advanced radiographic knee OA in the same person, and between OA and healthy reference knees. Methods: The sample was drawn from the Osteoarthritis Initiative (OAI) cohort and fulfilled the following criteria: OARSI medial JSN in one knee, no-JSN in the contra-lateral knee, BMI>25, frequent knee pain in both knees. The 28 participants who displayed OARSI JSN grades 2 or 3 in one (and grade 0 in the other) knee were matched 1:1 with subjects from the OAI healthy reference cohort without knee pain radiographic signs, or risk factors of incident knee OA, based on the same sex and similar body height. A sagittal fat-suppressed IM-weighted TSE sequence was used for segmentation of the entire IPFP (J.D.), volumetric 3D analysis of its morphology and signal, and for semi-quantitative evaluation of MOAKS synovitis scores (A.G.). Paired t-tests were used to compare JSN with contra-lateral non-JSN knees, and with matched reference knees. Results: The 28 JSN participants (21 medial JSN grade 2 and 7 grade 3; 21 women, 7 men) were 165±11 cm tall (age 61±10y; weight 87±14 kg, BMI 32.2±4.4). The matched healthy reference subjects were of similar height (165±10cm), but younger (54±6y) and less heavy (70±13 kg; BMI 26±2.7). No significant differences in IPFP volume, surface areas, or thickness were observed between JSN and no-JSN knees. Compared with healthy reference knees, JSN knees displayed a 10% larger IPFP anterior surface area (p<0.01), but a slightly lower thickness, and no significant difference in IPFP volume (Table 1). JSN knees displayed a significantly greater mean MRI signal intensity (SI) and greater MRI SI heterogeneity (i.e. standard deviation [SD]) than the no-JSN knees; further JSN knees displayed a substantially and significantly greater SD SI than healthy reference knees (Table 1: (b) 1⁄4 p<0.01; (c) 1⁄4 p<0.001)).

Quantitative relationship of thigh adipose tissue with pain, radiographic status, and progression of knee osteoarthritis: longitudinal findings from the osteoarthritis initiative.

The aim of this study was to explore the relationship of thigh subcutaneous fat (SCF) and intermuscular fat (IMF) content with knee osteoarthritis (KOA) cross-sectionally and longitudinally, using quantitative magnetic resonance imaging. Specifically, we examined relationships with frequent knee pain, various radiographic strata, and structural progression status of KOA. Subjects who showed between-knee discordance of frequent versus no pain (n = 48), osteophyte versus no radiographic KOA (n = 55), and radiographic joint space narrowing versus no joint space narrowing (n = 44) were selected from the Osteoarthritis Initiative. Knees with structural progression of KOA (n = 23) were compared with knees without progression. Axial thigh magnetic resonance images were used to determine IMF and SCF. Differences between knees and between baseline and 2-year follow-up were examined using paired t tests. Women displayed similar amounts of IMF, but twice the SCF of men. Limbs of women with frequently painful knees had statistically significant greater IMF areas (+4.2%; P = 0.05) than contralateral pain-free limbs did. No significant cross-sectional differences were observed between other strata. Men with structural progression appeared to have a greater longitudinal increase in SCF (+13.2%; P < 0.05) than did men without progression (-1.9%), and women with progression appeared to have a greater increase in IMF (+11.6%) than did those without progression (+1.5%). In women, painful knees display greater IMF content than do contralateral pain-free knees. Other between-knee comparisons did not reveal a regional association between radiographic KOA and thigh adipose tissue status. Structural progression of KOA may be associated with greater longitudinal increases in SCF in men and greater increases of IMF in women, compared with nonprogressive controls.