Association of radiographic features of osteoarthritis of the knee with knee pain: data from the Baltimore Longitudinal Study of Aging

The spectrum of anguish from osteoarthritis sparks physiological or psychological needs in the young-old and the old-old determined by gender

Knee osteoarthritis (KOA) inducing physiological pain and psychological health which is a public health issue in the older adults. However, research about the gender-specific effects on young-old and old-old is still scarce. The aim was to explore the vulnerability of physiology and psychology to KOA among the young-old and the old-old by gender. This case-control study recruited participants from health examinations at the Tri-Service General Hospital between March 2015 and October 2019. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the 12-item short-form survey (SF-12) were used to evaluate the health status and quality of life (QoL) of subjects. Kellgren-Lawrence grading system (KL) was adopted to assess knee radiographs of subjects, KL grade ≥ 2 as KOA patients (KL grade ≥ 3 as severe KOA patients) and KL grade < 2 as controls. Student t-test and χ2 test were used to compare the distribution differences between KOA patients and controls, including demographic data, health statuses and QoL. The association of KOA and QoL was determined using multiple regression analysis. There were 772 subjects (young-old, n = 543; old-old, n = 229) in this study, 406 KOA patients (including 85 severe KOA patients) and 366 healthy individuals. In the young-old, KOA may play a least role in health status and QoL. However, in the old-old, males with severe KOA would cause a decrease in SF-12 mental component summary score (MCS) (β= -13.75, 95% CI: -23.90 to -3.61); however, females with severe KOA would cause a decrease in SF-12 physical functioning domain (β = -19.44; 95% CI: -35.32 to -3.56). The spectrum of anguish from KOA leads to differential reduction of QoL determined by age and gender. This study provides a glimpse on physiological and psychological need among the young-old and the old-old with KOA by gender.

A novel classifier of radiographic knee osteoarthritis for use on knee DXA images is predictive of joint replacement in UK Biobank

Objectives

DXA scans may offer a novel means of evaluating radiographic knee OA (rKOA) in large population studies and through opportunistic screening. We aimed to develop and apply a semi-automated method for assessing rKOA using ≈20 000 knee DXA images from UK Biobank (UKB) and assess its face validity by checking for expected relationships with clinical outcomes.

Methods

Right knee DXA scans were manually annotated for osteophytes to derive corresponding grades. Joint space narrowing (JSN) grades in the medial joint compartment were determined from automatically measured minimum joint space width. Overall rKOA grade (0-4) was determined by combining osteophyte and JSN grades. Logistic regression was employed to investigate the associations of osteophyte, JSN and rKOA grades with knee pain and hospital-diagnosed KOA. Cox proportional hazards modelling was used to examine the associations of these variables with risk of subsequent total knee replacement (TKR).

Results

Of the 19 595 participants included (mean age 63.7 years), 19.5% had rKOA grade ≥1 (26.1% female, 12.5% male). Grade ≥1 osteophytes and grade ≥1 JSN were associated with knee pain, hospital-diagnosed KOA and TKR. Higher rKOA grades were linked to stronger associations with these clinical outcomes, with the most pronounced effects observed for TKR. Hazard ratios for the association of rKOA grades with TKR were 3.28, 8.75 and 28.63 for grades 1, 2 and 3-4, respectively.

Conclusions

Our DXA-derived measure of rKOA demonstrated a progressive relationship with clinical outcomes. These findings support the use of DXA for classifying rKOA in large epidemiological studies and in future population-based screening.

Multi-centre modified Delphi exercise to identify candidate items for classifying early-stage symptomatic knee osteoarthritis

OBJECTIVE

To generate a list of candidate items potentially useful for discriminating individuals with Early-stage Symptomatic Knee Osteoarthritis (EsSKOA) from those with other conditions and from established osteoarthritis (OA), and to reduce this list based on expert consensus.

DESIGN

We conducted a three-round online international modified Delphi exercise with OA clinicians and researchers ("OA experts"). In Round 1, participants reviewed 84 candidate items and nominated additional item(s) potentially useful for EsSKOA classification; those nominated by ≥3 participants were added. In Round 2, participants rated perceived usefulness of 108 items (1 [not at all useful] to 9 [extremely useful]). In Round 3, participants could revise their ratings after reviewing Round 2 group median and quartiles. Following Round 3, we retained items with a median usefulness score >5 and ≥33.3% of participants categorised the item as useful (7 to 9), overall and in subgroup analysis by clinician field.

RESULTS

There were 128 participants in Round 1 and 113 (88%) completed all rounds. We retained 77 items that spanned multiple domains (demographics, symptoms, physical exam, performance-based measures, imaging, laboratory investigations, and gross inspection/arthroscopy). Highly rated items included (median usefulness score): prior knee joint injury (8), diagnosis of OA in a different joint (7), and activity-related knee pain (7). The interquartile range was most often 3.

CONCLUSION

We identified 77 items that OA experts consider potentially useful for EsSKOA classification. The results highlight experts' uncertainty around item usefulness. Next, candidate items will be further assessed and reduced using data-driven and multicriteria decision analysis methods.

Patellar malalignment correlates with increased pain and increased synovial stress hormone levels-A cross-sectional study

PURPOSE

Risk factors for the development of pain in the context of knee osteoarthritis (KOA) remain unclear. Radiological findings often do not correlate with clinical findings, so other pathomechanisms in the development and perception of pain must play a role. The purpose of this study is to investigate the correlation of increased sympathetic nervous system (SNS) activity (measured by subjective and objective chronic stress parameters) with KOA severity, patellofemoral malalignment, and pain.

METHODS

47 patients with KOA were assessed. Radiological measurements of tibiofemoral and patellofemoral parameters (Kellgren-Lawrence-score, patellar tilt (PT), Caton-Deschamps-Index and Hepp´s classification) were performed and correlated with knee-specific questionnaires (WOMAC®, KSS©) and chronic stress questionnaires (PSQ-20). Additionally, parameters associated with chronic stress were quantified in synovial fluid and serum samples from patients.

RESULTS

PT correlated significantly with Caton-Deschamps-Index (r = 0.394,p = 0.006) and with medial patellofemoral joint space (r = 0.516,p<0.001). In addition, asymmetric trochlear groove (Hepp's classification > II) was associated with significantly higher PT values (p = 0.014). A negative correlation between PT and KSS©-symptoms subgroup was found (r = -0.340,p = 0.024). Patients with PT<5° had significantly higher scores in the Knee Society Score©-symptoms subgroup (p = 0.038). A positive and significant correlation between synovial aldosterone levels and PT was observed (r = 0.548,p = 0.042).

CONCLUSION

The results of this study indicate that patellar malalignment might correlate with increased pain. The previous specification of standard PT values must be reconsidered as even low PT values seem to play a role in the occurrence of patellofemoral osteoarthritis symptoms. Lower PT values might lead to aggravated symptoms in patients with KOA due to a narrow medial patellofemoral joint space. In addition, PT might induce the release of synovial stress biomarkers and thus contribute to the progression of KOA.

Pain Empathy and Its Association with the Clinical Pain in Knee Osteoarthritis Patients

Objective

Knee osteoarthritis (KOA) is a painful chronic disorder. Evidence has shown that a history of chronic pain plays an important role in shaping empathy. Empathy, a valuable indicator of social functioning that refers to an individual's ability to share the experiences of others, however, has been overlooked in KOA patients. This study aimed to investigate empathy and its association with clinical pain in KOA patients.

Methods

KOA patients (n=47) and healthy controls (HCs, n=44) completed two empathy-for-pain tasks: a pain judgment task in which participants judged whether a person in an image felt pain or not, and a pain rating task in which they estimated pain intensity for themselves and others. The Interpersonal Reactivity Index was used to measure participants' trait empathy, and clinical severity and psychological factors were assessed using relevant instruments.

Results

Compared to HCs, KOA patients showed higher accuracy when judging pain and non-pain images and reported overall higher pain intensity when rating for themselves and others. KOA patients also showed greater personal distress than HCs in terms of their self-reported empathy. Moreover, pain catastrophizing particularly mediated the relationship between pain severity and pain ratings for others, and depression, anxiety, and pain catastrophizing all mediated the association between pain severity and empathy-induced personal distress.

Conclusion

These findings suggest that patients with KOA have increased empathy, demonstrated by elevated sensitivity to pain-related scenes and intense emotional responses.

Deep learning approach to predict pain progression in knee osteoarthritis

OBJECTIVE

To develop and evaluate deep learning (DL) risk assessment models for predicting pain progression in subjects with or at risk of knee osteoarthritis (OA).

MATERIALS AND METHODS

The incidence and progression cohorts of the Osteoarthritis Initiative, a multi-center longitudinal study involving 9348 knees in 4674 subjects with or at risk of knee OA that began in 2004 and is ongoing, were used to conduct this retrospective analysis. A subset of knees without and with pain progression (defined as a 9-point or greater increase in pain score between baseline and two or more follow-up time points over the first 48 months) was randomly stratified into training (4200 knees with a mean age of 61.0 years and 60% female) and hold-out testing (500 knees with a mean age of 60.8 years and 60% female) datasets. A DL model was developed to predict pain progression using baseline knee radiographs. An artificial neural network was used to develop a traditional risk assessment model to predict pain progression using demographic, clinical, and radiographic risk factors. A combined model was developed to combine demographic, clinical, and radiographic risk factors with DL analysis of baseline knee radiographs. Area under the curve (AUC) analysis was performed using the hold-out testing dataset to evaluate model performance.

RESULTS

The traditional model had an AUC of 0.692 (66.9% sensitivity and 64.1% specificity). The DL model had an AUC of 0.770 (76.7% sensitivity and 70.5% specificity), which was significantly higher (p < 0.001) than the traditional model. The combined model had an AUC of 0.807 (72.3% sensitivity and 80.9% specificity), which was significantly higher (p < 0.05) than the traditional and DL models.

CONCLUSIONS

DL models using baseline knee radiographs had higher diagnostic performance for predicting pain progression than traditional models using demographic, clinical, and radiographic risk factors.

RADIOLOGICAL ASSESSMENT OF KNEE JOINT WIDTH DIFFERENCES IN OLDER ADULTS WITH SYMPTOMATIC MEDIAL KNEE OSTEOARTHRITIS

Knee osteoarthritis (OA) is a degenerative articular disease. The knee joint space width (JSW) is used for grading the severity of knee OA. However, there is a lack of research on differences in the widths of knee joints between both lower limbs in unilateral OA. The purpose of this research was to examine the radiological difference in the affected knee joint and contralateral knee joint by analyzing unilateral older adults with medial knee OA using both knees’ JSW differences. Twenty-five subjects with unilateral medial knee OA participated. X-ray radiographs were used to assess knee JSW, and the paired [Formula: see text]-test was performed to assess the knee joint gap width between the affected side and the unaffected side in the respective medial and lateral sides. The independent [Formula: see text]-test compared the differences between the lateral and medial knee JSWs on the affected side and unaffected side. The paired [Formula: see text]-test did not show a significant difference in the medial and lateral knee JSW on the affected side compared to the unaffected side ([Formula: see text]; 0.11). Meanwhile, the independent [Formula: see text]-test revealed a significant difference between the affected and unaffected sides ([Formula: see text]). This study showed no significant changes in affected knee JSWs compared to unaffected sides, but the difference between the lateral and medial JSWs was significant between the knees affected and unaffected by OA in the older adults with medial knee OA.

Low Rates of Radiographic Knee Osteoarthritis 5 Years After ACL Reconstruction or Rehabilitation Alone: The Delaware-Oslo ACL Cohort Study

BACKGROUND

Patients and clinicians often struggle to choose the optimal management strategy for posttraumatic knee osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury. An evaluation of radiographic outcomes after a decision-making and treatment algorithm applicable in clinical practice can help to inform future recommendations and treatment choices.

PURPOSE

To describe and compare 5-year radiographic outcomes and knee pain in individuals who had gone through our decision-making and treatment algorithm and chosen (1) early (<6 months) ACL reconstruction (ACLR) with pre- and postoperative rehabilitation, (2) delayed (>6 months) ACLR with pre- and postoperative rehabilitation, or (3) progressive rehabilitation alone.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

We included 276 patients with unilateral ACL injury from a prospective cohort study. Patients chose management using a shared decision-making process and treatment algorithm, and 5-year postoperative radiographs of the index and contralateral knees were assessed using the Kellgren and Lawrence (K&L) classification and minimum joint space width measurements. We defined radiographic tibiofemoral OA as K&L grade ≥2 and knee pain as a Knee injury and Osteoarthritis Outcome Score for Pain ≤72. To further explore early radiographic changes, we included alternative cutoffs for radiographic knee OA using K&L grade ≥2/osteophyte (definite osteophyte without joint space narrowing) and K&L grade ≥1.

RESULTS

At 5 years, 64% had undergone early ACLR; 11%, delayed ACLR; and 25%, progressive rehabilitation alone. Radiographic examination was attended by 187 patients (68%). Six percent of the cohort had radiographic tibiofemoral OA (K&L grade ≥2) in the index knee; 4%, in the contralateral knee. Using the alternative cutoffs at K&L grade ≥2/osteophyte and K&L grade ≥1, the corresponding numbers were 20% and 33% in the index knee and 18% and 29% in the contralateral knee. Six percent had a painful index knee. There were no statistically significant differences in any radiographic outcomes or knee pain among the 3 management groups.

CONCLUSION

There were no statistically significant differences in any 5-year radiographic outcomes or knee pain among the 3 management groups. Very few of the patients who participated in our decision-making and treatment algorithm had knee OA or knee pain at 5 years.

Absence of pain in subjects with advanced radiographic knee osteoarthritis

Background

To investigate the frequency of pain among subjects with advanced radiographic knee osteoarthritis (OA) defined as Kellgren–Lawrence (KL) grade 4 and clinical features associated with pain.

Methods

Subjects from the Hallym Aging Study (HAS), the Korean National Health and Nutrition Examination Survey (KNHANES), and the Osteoarthritis Initiative (OAI) were included. Participants were asked knee-specific questions regarding the presence of knee pain. Clinical characteristics associated with the presence of pain were evaluated with multivariable logistic regression analysis.

Results

The study population consisted of 504, 10,152 and 4796 subjects from HAS, KNHANES, and OAI, respectively. KL grade 4 OA was identified in 9.3, 7.6, and 11.5% of subjects, while pain was absent in 23.5, 31.2, and 5.9% of subjects in KL grade 4 knee OA, respectively. After multivariable analysis, female gender showed a significant association with pain in the KNHANES group, while in the OAI group, younger age did. Advanced knee OA patients without pain did not differ from non-OA subjects in most items of SF-12 in both Korean and OAI subjects. Total WOMAC score was not significantly different between non-OA and advanced knee OA subjects without pain in the OAI.

Conclusions

Our study showed that a considerable number of subjects with KL grade 4 OA did not report pain. In patients whose pain arises from causes other than structural damage of the joint, therapeutic decision based on knee X-ray would lead to suboptimal result. In addition, treatment options focusing solely on cartilage engineering, should be viewed with caution.

Relationship between radiological severity and physical and mental health in elderly individuals with knee osteoarthritis

Background

This study aimed to investigate the relationship between radiological severity, as assessed by the individual grades and grouped grades (grades “0 and 1” and “2 to 4”) of the Kellgren-Lawrence scale (K&Ls), and depression symptoms, cognitive loss, risk of falls, and quality of life in relation to knee osteoarthritis, as assessed by other instruments.

Methods

Data recorded between 2013 and 2014 in Amparo (São Paulo, Brazil) were retrieved for analysis. A total of 181 elderly patients who had knee osteoarthritis and underwent a radiologic exam were evaluated for depressive symptoms, cognitive loss, quality of life, and risk of falls by the Geriatric Depression Scale (GDS), Mini-Mental State Examination (MMSE), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), timed up and go test (TUG), and Berg balance scale (BBS). For statistical analyses, Fisher’s exact test, Mann-Whitney test, Kruskal-Wallis test, and Spearman’s coefficient analysis were used.

Results

There was no significant relationship between the scores of the instruments investigated and the individual K&Ls grades. However, when the K&Ls scores were assessed by groups, grades “2 to 4” were associated with the worst WOMAC score and the highest frequency and risk of falls according to the BBS but not according to TUG. For the GDS and MMSE, no significant relationships with the K&Ls grades were found. In addition, the K&Ls grade was correlated with the WOMAC score, regardless of the domain.

Conclusion

The radiological scores of the Kellgren-Lawrence (K&L) scale were associated with poorer WOMAC and BBS scores only when the K&Ls scores were evaluated in groups, and the WOMAC score was associated with an increase in the radiological grade.

Can We Predict Severity of Osteoarthritis of Knees and Compartmental Involvement Based on a Set of Predefined Clinical Questions in Patients of Knee Pain?

BACKGROUND

We investigated whether the severity of Osteoarthritis (OA) knees can be predicted based on a set of predefined clinical questions (PCQs) about activities of daily living (ADL). We studied the association of demographic factors and advanced radiographic OA (KL 3 and 4) and the relationship between various physical activities and radiographic involvement of knee joint compartments based on PCQs.

MATERIALS AND METHODS

Demographic data, radiographic grading of knee OA and PCQs score, were obtained prospectively. Patients' responses to PCQs were marked as scores-that were predefined and graded according to the severity of knee pain. Radiographic knee OA grades were dichotomized and patients were classified as either negative (KL grade 1, 2) or positive (KL grade 3, 4). Multivariate logistic regression was performed to obtain the adjusted odds for total PCQs score in relation with positive radiographic OA considering confounders like age, gender and BMI in the model. Log odds score (LOS) were obtained and ROC analysis was performed on scores to obtain the cut-off value for the screening of knee OA in patients of knee pain.

RESULTS

Age and BMI were significantly negatively correlated with PCQs score (r = - 0.473; P < 0.0001 and r = - 0.136; P = 0.046). PCQs scores were significantly lower in females (P = 0.031). Total PCQs score had corresponding OR of 0.901 (P = 0.002) towards knee OA after adjusting for age, gender and BMI. Multivariate model-based LOS resulted in a cut-off of 1.315, which had a sensitivity of 85.5%, specificity of 66.7% and PPV of 92.7%.

CONCLUSION

Severity of knee OA can be predicted based on PCQs. PCQs can predict severity of knee OA and patellofemoral or medial tibiofemoral compartment without radiographs. LOS based on demographics and total PCQs score can be developed as a screening tool for advanced knee OA.

Clinical characteristics and disability in patients with knee osteoarthritis: real world experience from Bulgaria

OBJECTIVES

Although knee osteoarthritis (KOA) is a leading cause of impaired functioning among older adults globally, little is still known about the complex mechanisms of disability accumulation in these patients. The aim of the study was to analyze the clinical parameters of patients with KOA in a Bulgarian population and to determine which of these clinical characteristics define disability to the greatest extent.

MATERIAL AND METHODS

Patients aged 40-80 years with symptomatic KOA were included. The assessment tools for pain, clinical disease severity, and disability were the pain visual analogue scale (VAS) and disease-specific questionnaires: Algofunctional Index of Lequesne, Western Ontario and McMaster Universities OA Index (WOMAC), and the Health Assessment Questionnaire-Disability Index (HAQ-DI), respectively. Radiographs of the knees were obtained and graded according to the Kellgren-Lawrence (KL) system.

RESULTS

One hundred and thirty-two patients (81% women) participated in the study. The median values of VAS (mm), WOMAC, Lequesne, and HAQ-DI scores were 52, 37.5, 11, 0.88, respectively. Men had milder disease, resulting in lower VAS, WOMAC, Lequesne, and HAQ-DI scores and less structural damage compared to women (p < 0.05). WOMAC index correlated positively with age of the patients but not with duration of the complaints. Patients with severe and very severe pain did not differ in their HAQ-DI, disease severity and KL grading. WOMAC physical function score and Lequesne index were independent predictors for the HAQ-DI in patients with KOA.

CONCLUSIONS

Bulgarian patients with KOA had moderate disability which showed a strong relationship with physical function of WOMAC and disease severity. Multiple layers of causality coexist to determine the knee pain in Bulgarian patients with KOA.

Modeling and predicting osteoarthritis progression: data from the osteoarthritis initiative

OBJECTIVE

The goal of this study was to model the longitudinal progression of knee osteoarthritis (OA) and build a prognostic tool that uses data collected in 1 year to predict disease progression over 8 years.

DESIGN

To model OA progression, we used a mixed-effects mixture model and 8-year data from the Osteoarthritis Initiative (OAI)-specifically, joint space width measurements from X-rays and pain scores from the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire. We included 1243 subjects who at enrollment were classified as being at high risk of developing OA based on age, body mass index (BMI), and medical and occupational histories. After clustering subjects based on radiographic and pain progression, we used clinical variables collected within the first year to build least absolute shrinkage and selection (LASSO) regression models for predicting the probabilities of belonging to each cluster. Areas under the receiver operating characteristic curve (AUC) represent predictive performance on held-out data.

RESULTS

Based on joint space narrowing, subjects clustered as progressing or non-progressing. Based on pain scores, they clustered as stable, improving, or worsening. Radiographic progression could be predicted with high accuracy (AUC = .86) using data from two visits spanning 1 year, whereas pain progression could be predicted with high accuracy (AUC = .95) using data from a single visit. Joint space narrowing and pain progression were not associated.

CONCLUSION

Statistical models for characterizing and predicting OA progression promise to improve clinical trial design and OA prevention efforts in the future.

What is the role of imaging in the clinical diagnosis of osteoarthritis and disease management?

While OA is predominantly diagnosed on the basis of clinical criteria, imaging may aid with differential diagnosis in clinically suspected cases. While plain radiographs are traditionally the first choice of imaging modality, MRI and US also have a valuable role in assessing multiple pathologic features of OA, although each has particular advantages and disadvantages. Although modern imaging modalities provide the capability to detect a wide range of osseous and soft tissue (cartilage, menisci, ligaments, synovitis, effusion) OA-related structural damage, this extra information has not yet favourably influenced the clinical decision-making and management process. Imaging is recommended if there are unexpected rapid changes in clinical outcomes to determine whether it relates to disease severity or an additional diagnosis. On developing specific treatments, imaging serves as a sensitive tool to measure treatment response. This narrative review aims to describe the role of imaging modalities to aid in OA diagnosis, disease progression and management. It also provides insight into the use of these modalities in finding targeted treatment strategies in clinical research.

Effect of a physiotherapy rehabilitation program on knee osteoarthritis in patients with different pain intensities

[Purpose] To examine the effect of physiotherapy rehabilitation program on moderate knee osteoarthritis in patients with different pain intensities. [Subjects and Methods] Sixty subjects (37 men and 23 women) with moderate knee osteoarthritis participated in the current study. Randomization software was used to select the participating subjects' numbers from the clinic records. They were classified into three groups according to pain intensity: mild, moderate, and severe pain groups. All groups underwent a standard set of pulsed electromagnetic field, ultrasound, stretching exercises, and strengthening exercises. Pain intensity, knee range of motion, knee function, and isometric quadriceps strength were evaluated using the visual analogue scale, universal goniometer, Western Ontario and McMaster Universities osteoarthritis index, and Jamar hydraulic dynamometer, respectively. The evaluation was performed before and after a 4-week rehabilitation program. [Results] All groups showed significant differences in pain intensity, knee range of motion, isometric quadriceps strength, and knee function. The score change in moderate pain group was significantly greater than those in mild and severe pain groups. [Conclusion] Pain intensity is one of the prominent factors that are responsible for the improvement of knee osteoarthritis. Consequently, pain intensity should be considered during rehabilitation of knee osteoarthritis.

Acupuncture for chronic pain and depression in primary care: a programme of research

Background

There has been an increase in the utilisation of acupuncture in recent years, yet the evidence base is insufficiently well established to be certain about its clinical effectiveness and cost-effectiveness. Addressing the questions related to the evidence base will reduce uncertainty and help policy- and decision-makers with regard to whether or not wider access is appropriate and provides value for money.

Aim

Our aim was to establish the most reliable evidence on the clinical effectiveness and cost-effectiveness of acupuncture for chronic pain by drawing on relevant evidence, including recent high-quality trials, and to develop fresh evidence on acupuncture for depression. To extend the evidence base we synthesised the results of published trials using robust systematic review methodology and conducted a randomised controlled trial (RCT) of acupuncture for depression.

Methods and results

We synthesised the evidence from high-quality trials of acupuncture for chronic pain, consisting of musculoskeletal pain related to the neck and low back, osteoarthritis of the knee, and headache and migraine, involving nearly 18,000 patients. In an individual patient data (IPD) pairwise meta-analysis, acupuncture was significantly better than both sham acupuncture (p < 0.001) and usual care (p < 0.001) for all conditions. Using network meta-analyses, we compared acupuncture with other physical therapies for osteoarthritis of the knee. In both an analysis of all available evidence and an analysis of a subset of better-quality trials, using aggregate-level data, we found acupuncture to be one of the more effective therapies. We developed new Bayesian methods for analysing multiple individual patient-level data sets to evaluate heterogeneous continuous outcomes. An accompanying cost-effectiveness analysis found transcutaneous electrical nerve stimulation (TENS) to be cost-effective for osteoarthritis at a threshold of £20,000 per quality-adjusted life-year when all trials were synthesised. When the analysis was restricted to trials of higher quality with adequate allocation concealment, acupuncture was cost-effective. In a RCT of acupuncture or counselling compared with usual care for depression, in which half the patients were also experiencing comorbid pain, we found acupuncture and counselling to be clinically effective and acupuncture to be cost-effective. For patients in whom acupuncture is inappropriate or unavailable, counselling is cost-effective.

Conclusion

We have provided the most robust evidence from high-quality trials on acupuncture for chronic pain. The synthesis of high-quality IPD found that acupuncture was more effective than both usual care and sham acupuncture. Acupuncture is one of the more clinically effective physical therapies for osteoarthritis and is also cost-effective if only high-quality trials are analysed. When all trials are analysed, TENS is cost-effective. Promising clinical and economic evidence on acupuncture for depression needs to be extended to other contexts and settings. For the conditions we have investigated, the drawing together of evidence on acupuncture from this programme of research has substantially reduced levels of uncertainty. We have identified directions for further research. Our research also provides a valuable basis for considering the potential role of acupuncture as a referral option in health care and enabling providers and policy-makers to make decisions based on robust sources of evidence.

Trial registration

Current Controlled Trials ISRCTN63787732.

Funding

The National Institute for Health Research Programme Grants for Applied Research programme.

Managing knee osteoarthritis with yoga or aerobic/strengthening exercise programs in older adults: a pilot randomized controlled trial

Although exercise is often recommended for managing osteoarthritis (OA), limited evidence-based exercise options are available for older adults with OA. This study compared the effects of Hatha yoga (HY) and aerobic/strengthening exercises (ASE) on knee OA. Randomized controlled trial with three arms design was used: HY, ASE, and education control. Both HY and ASE groups involved 8 weekly 45-min group classes with 2-4 days/week home practice sessions. Control group received OA education brochures and weekly phone calls from study staff. Standardized instruments were used to measure OA symptoms, physical function, mood, spiritual health, fear of falling, and quality of life at baseline, 4 and 8 weeks. HY/ASE adherences were assessed weekly using class attendance records and home practice video recordings. Primary analysis of the difference in the change from baseline was based on intent-to-treat and adjusted for baseline values. Eight-three adults with symptomatic knee OA completed the study (84% female; mean age 71.6 ± 8.0 years; mean BMI 29.0 ± 7.0 kg/m²). Retention rate was 82%. Compared to the ASE group at 8 weeks, participants in the HY group had a significant improvement from baseline in perception of OA symptoms (-9.6 [95% CI -15.3, -4]; p = .001), anxiety (-1.4 [95% CI -2.7, -0]; p = .04), and fear of falling (-4.6 [-7.5, -1.7]; p = .002). There were no differences in class/home practice adherence between HY and ASE. Three non-serious adverse events were reported from the ASE group. Both HY and ASE improved symptoms and function but HY may have superior benefits for older adults with knee OA. Trial registration The full trial protocol is available at clinicaltrials.gov (NCT02525341).

Radiographic assessment of leg alignment and grading of knee osteoarthritis: A critical review

Knee osteoarthritis (OA) is a progressive joint disease hallmarked by cartilage and bone breakdown and associated with changes to all of the tissues in the joint, ultimately causing pain, stiffness, deformity and disability in many people. Radiographs are commonly used for the clinical assessment of knee OA incidence and progression, and to assess for risk factors. One risk factor for the incidence and progression of knee OA is malalignment of the lower extremities (LE). The hip-knee-ankle (HKA) angle, assessed from a full-length LE radiograph, is ideally used to assess LE alignment. Careful attention to LE positioning is necessary to obtain the most accurate measurement of the HKA angle. Since full-length LE radiographs are not always available, the femoral shaft - tibial shaft (FS-TS) angle may be calculated from a knee radiograph instead. However, the FS-TS angle is more variable than the HKA angle and it should be used with caution. Knee radiographs are used to assess the severity of knee OA and its progression. There are three types of ordinal grading scales for knee OA: global, composite and individual feature scales. Each grade on a global scale describes one or more features of knee OA. The entire description must be met for a specific grade to be assigned. The Kellgren-Lawrence scale is the most commonly-used global scale. Composite scales grade several features of knee OA individually and sum the grades to create a total score. One example is the compartmental grading scale for knee OA. Composite scales can respond to change in a variety of presentations of knee OA. Individual feature scales assess one or more OA features individually and do not calculate a total score. They are most often used to monitor change in one OA feature, commonly joint space narrowing. The most commonly-used individual feature scale is the OA Research Society International atlas. Each type of scale has its advantages; however, composite scales may offer greater content validity. Responsiveness to change is unknown for most scales and deserves further evaluation.

Synovial chemokine expression and relationship with knee symptoms in patients with meniscal tears

OBJECTIVE

In patients with knee OA, synovitis is associated with knee pain and symptoms. We previously identified synovial mRNA expression of a set of chemokines (CCL19, IL-8, CCL5, XCL-1, CCR7) associated with synovitis in patients with meniscal tears but without radiographic OA. CCL19 and CCR7 were also associated with knee symptoms. This study sought to validate expression of these chemokines and association with knee symptoms in more typical patients presenting for meniscal arthroscopy, many who have pre-existing OA.

DESIGN

Synovial fluid (SF) and biopsies were collected from patients undergoing meniscal arthroscopy. Synovial mRNA expression was measured using quantitative RT-PCR. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was administered preoperatively. Regression analyses determined if associations between chemokine mRNA levels and KOOS scores were independent of other factors including radiographic OA. CCL19 in SF was measured by ELISA, and compared to patients with advanced knee OA and asymptomatic organ donors.

RESULTS

90% of patients had intra-operative evidence of early cartilage degeneration. CCL19, IL-8, CCL5, XCL1, CCR7 transcripts were detected in all patients. Synovial CCL19 mRNA levels independently correlated with KOOS Activities of Daily Living (ADL) scores (95% CI [-8.071, -0.331], P = 0.036), indicating higher expression was associated with more knee-related dysfunction. SF CCL19 was detected in 7 of 10 patients, compared to 4 of 10 asymptomatic donors.

CONCLUSION

In typical patients presenting for meniscal arthroscopy, synovial CCL19 mRNA expression was associated with knee-related difficulty with ADL, independent of other factors including presence of radiographic knee OA.

Sensitivity and sensitisation in relation to pain severity in knee osteoarthritis: trait or state?

OBJECTIVES

It is not clear whether heightened pain sensitivity in knee osteoarthritis (OA) is related to sensitisation induced by nociceptive input from OA pathology ('state') versus other confounding factors. Conversely, some individuals may be predisposed to sensitisation irrespective of OA ('trait').

METHODS

The Multicenter Osteoarthritis Study is a longitudinal cohort of persons with or at risk of knee OA. We obtained knee X-rays, pain questionnaires and comprehensive assessment of factors that can influence pain sensitivity. We examined the relation of sensitisation and sensitivity assessed by mechanical temporal summation (TS) and pressure pain thresholds (PPTs) to knee OA and knee pain severity. To test whether sensitisation and sensitivity is a 'state' induced by OA pathology, we examined the relation of PPT and TS to knee OA duration and severity.

RESULTS

In 2126 subjects (mean age 68, mean body mass index (BMI) 31, 61% female), PPT and TS were not associated with radiographic OA (ORs 0.9-1.0 for PPT and TS; p>0.05). However, PPT and TS were associated with pain severity (ORs: 1.7-2.0 for PPT; 1.3-1.6 for TS; p<0.05). Knee OA duration and radiographic severity were not associated with PPT or TS.

CONCLUSIONS

PPT and TS were associated with OA-related pain, but not radiographic OA after accounting for pertinent confounders in this large cohort. Lack of association with disease duration suggests at least some sensitisation and pain sensitivity may be a trait rather than state. Understanding the relationship between pathological pain and pain sensitivity/sensitisation offers insight into OA pain risk factors and pain management opportunities.

Knee osteoarthritis, body mass index and pain: data from the Osteoarthritis Initiative

OBJECTIVE

This study aimed to determine whether BMI increases knee pain as measured from self-reported surveys even when controlling for OA severity as measured by osteophytes and joint space narrowing visible on X-rays.

METHODS

Data available through the Osteoarthritis Initiative (OAI) were analysed, which included a sample of 4769 individuals, to answer the above question regarding OA, excess weight and pain. OA severity was assessed through baseline X-rays on right knees that were scored on a composite quasi-Kellgren and Lawrence grade. Weight was assessed through BMI. Pain was assessed through self-reports of the WOMAC pain subset as well as a 30-day pain severity question based on a 0-10 scale. Data were analysed using SPSS and analyses of covariance (ANCOVAs) were run to examine models adjusted for age, smoking, prior injury, pain medication and Heberden's nodes. Critical alpha levels were set at 0.05.

RESULTS

The results reported here confirm that knee pain does increase with OA severity. However, ANCOVA multiple regressions with controls reveal that even when taking into account OA severity, individuals with higher BMIs experience greater pain than individuals with lower BMIs.

CONCLUSION

Weight loss may reduce knee OA pain even if the osteological symptoms are not treated.

Patellar resurfacing in posterior cruciate ligament retaining total knee arthroplasty (PATRES): design of a randomized controlled clinical trial

BACKGROUND

Anterior knee pain may occur after total knee arthroplasty (TKA). Patellar resurfacing, which is considered to lower the incidence of anterior knee pain after TKA, remains controversial. In the present study clinical and radiological outcomes after TKA performed on patients with clinical and radiological signs of femorotibial and patellofemoral osteoarthritis (OA) with and without patellar resurfacing will be compared.

METHODS/DESIGN

Fifty patients will be included in a randomized controlled trial. Patients scheduled for TKA with clinical and radiological signs of femorotibial and patellofemoral OA will be included. Arthritis of the patellofemoral joint was determined based on the preoperative Baldini and Merchant X-ray views, which is assessed by the orthopaedic surgeon who treats the patient. Exclusion criteria are rheumatoid arthritis, history of patellar fracture, tuberosity transposition, high tibial osteotomy (HTO), hip arthroplasty and posterior cruciate ligament insufficiency. Patients will be randomized to undergo TKA either with or without patellar resurfacing. Outcomes will be assessed preoperatively, at 6 weeks and at 6, 12, 18 and 24 months postoperatively. Primary outcome measure is the patellofemoral scoring system according to Baldini. Secondary outcome measures are the Knee Society clinical rating system (KSS) and the Knee Osteoarthritis Outcome Scale (KOOS) scores. Conventional weight-bearing radiographs, and views according to Baldini will be used to asses component loosening, wear, and patellofemoral problems including fracture or loosening of resurfaced patellae, subluxation and wear of non-resurfaced patellae.

DISCUSSION

There is no consensus regarding patellar resurfacing during primary TKA. Current prospective studies fail to determine any differences in clinical outcome among patients after TKA with or without patellar resurfacing. This randomized controlled trial has been designed to determine the effectiveness of patellar resurfacing during TKA in patients undergoing TKA who have clinical and radiological signs of tibiofemoral and patellofemoral OA, using a specific patellofemoral outcome measurement.

TRIAL REGISTRATION

Netherlands Trial Registry NTR3108.

Levels of neuropeptide Y in synovial fluid relate to pain in patients with knee osteoarthritis

Background

The precise etiology of knee osteoarthritis (KOA) pain remains highly controversial and there is no known effective treatment. Due to the known and suggested effects of neuropeptide Y (NPY) on pain, we have sought to investigate the relationship between the concentration of NPY in synovial fluid of knee, pain of KOA, and structural severity of KOA.

Methods

One hundred KOA patients and twenty healthy participants (control group) were recruited. The pain and the radiographic grade of KOA were assessed separately by Hideo Watanabe’s pain score and Tomihisa Koshino’s scoring system. Synovial fluid of knee from all participants was collected with arthrocentesis. Radioimmunoassay was used to examine the concentration of NPY in synovial fluid of knee.

Results

Concentrations of NPY in synovial fluid were significantly higher in KOA patients (124.7 ± 33.4 pg/mL) compared with controls (64.8 ± 26.3 pg/mL) (p = 0.0297). According to Hideo Watanabe’s pain score, 100 KOA patients were divided into 5 subgroups: no pain (n = 12), mild pain (n = 25), moderate pain (n = 37), strong pain (n = 19) and severe pain (n = 7). Within the KOA group, significantly higher concentrations of NPY were found in each subgroup as pain intensified (no pain 81.4 ± 11.7 pg/mL, mild pain 99.1 ± 23.2 pg/mL, moderate pain 119.9 ± 31.5 pg/mL, strong pain 171.2 ± 37.3 pg/mL and severe pain 197.3 ± 41.9 pg/mL). Meanwhile, according to Tomihisa Koshino’s scoring system, 100 KOA patients were divided into 3 subgroups: early stage (n = 30), middle stage (n = 53), advanced stage (n = 17). Concentrations of NPY in middle and advanced stage groups of KOA patients were significant higher than early stage group of KOA patients (early stage 96.4 ± 27.1 pg/mL, middle stage 153.3 ± 16.9 pg/mL, advanced stage 149.5 ± 36.7 pg/mL) (p = 0.0163, p = 0.0352). Concentrations of NPY in advanced stage group of KOA patients has no significant difference compare with middle stage group of KOA patients (p = 0. 2175).

Conclusions

This study demonstrated the presence and variation of concentrations of NPY in the KOA joint fluid, suggesting a role for NPY as a putative regulator of pain transmission and perception in KOA pain.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2474-15-319) contains supplementary material, which is available to authorized users.

Anterior cruciate ligament injury and radiologic progression of knee osteoarthritis: a systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis after anterior cruciate ligament (ACL) injury has previously been reported. However, there has been no meta-analysis reporting the development and progression of osteoarthritis.

PURPOSE

We present the first meta-analysis reporting on the development and progression of osteoarthritis after ACL injury at a minimum mean follow-up of 10 years, using a single and widely accepted radiologic classification, the Kellgren & Lawrence classification.

STUDY DESIGN

Meta-analysis.

METHOD

Articles were included for systematic review if they reported radiologic findings of ACL-injured knees and controls using the Kellgren & Lawrence classification at a minimum mean follow-up period of 10 years. Appropriate studies were then included for meta-analysis.

RESULTS

Nine studies were included for systematic review, of which 6 studies were further included for meta-analysis. One hundred twenty-one of 596 (20.3%) ACL-injured knees had moderate or severe radiologic changes (Kellgren & Lawrence grade III or IV) compared with 23 of 465 (4.9%) uninjured ACL-intact contralateral knees. After ACL injury, irrespective of whether the patients were treated operatively or nonoperatively, the relative risk (RR) of developing even minimal osteoarthritis was 3.89 (P < .00001), while the RR of developing moderate to severe osteoarthritis (grade III and IV) was 3.84 (P < .0004). Nonoperatively treated ACL-injured knees had significantly higher RR (RR, 4.98; P < .00001) of developing any grade of osteoarthritis compared with those treated with reconstructive surgery (RR, 3.62; P < .00001). Investigation of progression to moderate or severe osteoarthritis (grade III or IV only) after 10 years showed that ACL-reconstructed knees had a significantly higher RR (RR, 4.71; P < .00001) compared with nonoperative management (RR, 2.41; P = .54). It was not possible to stratify for return to sports among the patients undergoing ACL reconstruction.

CONCLUSION

Results support the proposition that ACL injury predisposes knees to osteoarthritis, while ACL reconstruction surgery has a role in reducing the risk of developing degenerative changes at 10 years. However, returning to sports activities after ligament reconstruction may exacerbate the development of arthritis.

Exercise and osteoarthritis: cause and effects

Osteoarthritis (OA) is a common chronic joint condition predominantly affecting the knee, hip, and hand joints. Exercise plays a role in the development and treatment of OA but most of the literature in this area relates to knee OA. While studies indicate that exercise and physical activity have a generally positive effect on healthy cartilage metrics, depending upon the type of the activity and its intensity, the risk of OA development does appear to be moderately increased with sporting participation. In particular, joint injury associated with sports participation may be largely responsible for this increased risk of OA with sport. Various repetitive occupational tasks are also linked to greater likelihood of OA development. There are a number of physical impairments associated with OA including pain, muscle weakness and altered muscle function, reduced proprioception and postural control, joint instability, restricted range of motion, and lower aerobic fitness. These can result directly from the OA pathological process and/or indirectly as a result of factors such as pain, effusion, and reduced activity levels. These impairments and their underlying physiology are often targeted by exercise interventions and evidence generally shows that many of these can be modified by specific exercise. There is currently little clinical trial evidence to show that exercise can alter mechanical load and structural disease progression in those with established OA, although a number of impairments, that are amenable to change with exercise, appears to be associated with increased mechanical load and/or disease progression in longitudinal studies.

Presence and extent of severe facet joint osteoarthritis are associated with back pain in older adults

OBJECTIVE

To determine whether the presence and extent of severe lumbar facet joint osteoarthritis (OA) are associated with back pain in older adults, accounting for disc height narrowing and other covariates.

DESIGN

Two hundred and fifty-two older adults from the Framingham Offspring Cohort (mean age 67 years) were studied. Participants received standardized computed tomography (CT) assessments of lumbar facet joint OA and disc height narrowing at the L2-S1 interspaces using four-grade semi-quantitative scales. Severe facet joint OA was defined according to the presence and/or degree of joint space narrowing, osteophytosis, articular process hypertrophy, articular erosions, subchondral cysts, and intraarticular vacuum phenomenon. Severe disc height narrowing was defined as marked narrowing with endplates almost in contact. Back pain was defined as participant report of pain on most days or all days in the past 12 months. We used multivariable logistic regression to examine associations between severe facet joint OA and back pain, adjusting for key covariates including disc height narrowing, sociodemographics, anthropometrics, and health factors.

RESULTS

Severe facet joint OA was more common in participants with back pain than those without (63.2% vs 46.7%; P = 0.03). In multivariable analyses, presence of any severe facet joint OA remained significantly associated with back pain (odds ratio (OR) 2.15 [95% confidence interval (CI) 1.13-4.08]). Each additional joint with severe OA conferred greater odds of back pain [OR per joint 1.20 (95% CI 1.02-1.41)].

CONCLUSIONS

The presence and extent of severe facet joint OA on CT imaging are associated with back pain in community-based older adults, independent of sociodemographics, health factors, and disc height narrowing.

The epidemiology and impact of pain in osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis and a leading cause of disability worldwide, largely due to pain, the primary symptom of the disease. The pain experience in knee OA in particular is well-recognized as typically transitioning from intermittent weight-bearing pain to a more persistent, chronic pain. Methods to validly assess pain in OA studies have been developed to address the complex nature of the pain experience. The etiology of pain in OA is recognized to be multifactorial, with both intra-articular and extra-articular risk factors. Nonetheless, greater insights are needed into pain mechanisms in OA to enable rational mechanism-based management of pain. Consequences of pain related to OA contribute to a substantial socioeconomic burden.

Genomics of pain in osteoarthritis

Osteoarthritis (OA) accounts for the majority of the disease burden for musculoskeletal disorders and is one of the leading causes of disability worldwide. This disability is the result not of the cartilage loss that defines OA radiographically, but of the chronic pain whose presence defines symptomatic OA. It is becoming clear that many genes, each with a small effect size, contribute to the risk of developing OA. However, the genetics of OA pain are only just starting to be explored. This review will describe the first genes to have been identified in genomic studies of OA pain, as well as the possible dual roles of genes previously identified in genomic studies of OA in the context of pain. Difficulties associated with attempting to characterise the genetics of OA pain will be discussed and promising future avenues of research into genetic and epigenetic factors affecting OA pain described.

The effect of healing touch on the pain and mobility of persons with osteoarthritis: a feasibility study

The aims of this pilot study were to investigate the effects of Healing Touch (HT) on the pain level, joint function, mobility, and depression in persons with osteoarthritis (OA) of the knee joint(s). A randomized controlled trial using a repeated measures design was used. Cognitively intact persons (institutionalized and community) with a diagnosis of OA of the knee joint(s) received either HT sessions three times per week for 6 weeks (n = 12) or weekly friendly visits (FV) (n = 7). The HT sessions were delivered by a team of two nurses certified as HT practitioners and the FV was conducted by a nurse. All subjects continued to receive their standard care including the methods they had been using to relieve their joint pain. The two groups were similar regarding demographic variables, number of knees affected, co-morbidities, pain medications used and outcome variables at baseline. Two pain outcome measures (intensity and life interference) produced significant interaction effects. Two joint outcome measures (extension and extensor lag) also produced significant interaction effects. Furthermore, the HT group demonstrated significant improvements in 9 of the 12 outcome variables (75%) while no significant improvements occurred in the FV group. The HT group exhibited sustained effects (3 weeks post treatments) in three outcome variables. The reduction in joint pain and improvement in joint function suggest that biofield therapies could be effective non-pharmacological adjuncts to treatment of OA.

A comparative study of meniscectomy and nonoperative treatment for degenerative horizontal tears of the medial meniscus

BACKGROUND

It is still debated whether a degenerative horizontal tear of the medial meniscus should be treated with surgery.

HYPOTHESIS

The clinical outcomes of arthroscopic meniscectomy will be better than those of nonoperative treatment for a degenerative horizontal tear of the medial meniscus.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 102 patients with knee pain and a degenerative horizontal tear of the posterior horn of the medial meniscus on magnetic resonance imaging were included in this study between January 2007 and July 2009. The study included 81 female and 21 male patients with an average age of 53.8 years (range, 43-62 years). Fifty patients underwent arthroscopic meniscectomy (meniscectomy group), and 52 patients underwent nonoperative treatment with strengthening exercises (nonoperative group). Functional outcomes were compared using a visual analog scale (VAS) for pain, Lysholm knee score, Tegner activity scale, and patient subjective knee pain and satisfaction. Radiological evaluations were performed using the Kellgren-Lawrence classification to evaluate osteoarthritic changes.

RESULTS

In terms of clinical outcomes, meniscectomy did not provide better functional improvement than nonoperative treatment. At the final follow-up, the average VAS scores were 1.8 (range, 1-5) in the meniscectomy group and 1.7 (range, 1-4) in the nonoperative group (P = .675). The average Lysholm knee scores at 2-year follow-up were 83.2 (range, 52-100) and 84.3 (range, 58-100) in the meniscectomy and nonoperative groups, respectively (P = .237). In addition, the average Tegner activity scale and subjective satisfaction scores were not significantly different between the 2 groups. Although most patients initially had intense knee pain with mechanical symptoms, both groups reported a relief in knee pain, improved knee function, and a high level of satisfaction with treatment (P < .05 for all values). Two patients in the meniscectomy group and 3 in the nonoperative group with Kellgren-Lawrence grade 1 progressed to grade 2 at the 2-year follow-up.

CONCLUSION

There were no significant differences between arthroscopic meniscectomy and nonoperative management with strengthening exercises in terms of relief in knee pain, improved knee function, or increased satisfaction in patients after 2 years of follow-up.

Association of severity of coexisting patellofemoral disease with increased impairments and functional limitations in patients with knee osteoarthritis

OBJECTIVE

To evaluate the association between severity of coexisting patellofemoral (PF) disease with lower extremity impairments and functional limitations in patients with tibiofemoral (TF) osteoarthritis (OA).

METHODS

Radiographic views of the TF and PF compartments, knee extension strength, and knee range of motion were obtained for 167 patients with knee OA. Additionally, knee-specific symptoms and functional limitations were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Activities of Daily Living Scale (ADLS).

RESULTS

Moderate/severe PFOA was associated with lower knee extension strength (mean ± SD 1.4 ± 0.5 Nm/body weight [BW]) compared to no PFOA (mean ± SD 1.8 ± 0.5 Nm/BW). Additionally, total knee range of motion was significantly lower for patients with moderate/severe PFOA (mean ± SD 120.8° ± 14.4°) compared to no PFOA (mean ± SD 133.5° ± 10.7°) and mild PFOA (mean ± SD 125.8° ± 13.0°). Moderate/severe PFOA and mild PFOA were also associated with less pain while standing (odds ratio [OR] 0.2, 95% confidence interval [95% CI] 0.1-0.7 and OR 0.2, 95% CI 0.1-0.6, respectively) on the WOMAC, and moderate/severe PFOA was associated with greater difficulty with going downstairs (OR 2.9, 95% CI 1.0-8.1) on the ADLS.

CONCLUSION

It appears that knees with more severe coexisting PF disease demonstrate features distinct from those observed in TFOA in isolation or in combination with mild PF disease. Treatment strategies targeting the PF joint may be warranted to mitigate the specific lower extremity impairments and functional problems present in this patient population.

Identifying phenotypes of knee osteoarthritis by separate quantitative radiographic features may improve patient selection for more targeted treatment

OBJECTIVE

Expression of osteoarthritis (OA) varies significantly between individuals, and over time, suggesting the existence of different phenotypes, possibly with specific etiology and targets for treatment. Our objective was to identify phenotypes of progression of radiographic knee OA using separate quantitative features.

METHODS

Separate radiographic features of OA were measured by Knee Images Digital Analysis (KIDA) in individuals with early knee OA (the CHECK cohort: Cohort Hip & Cohort Knee), at baseline and at 2-year and 5-year followup. Hierarchical clustering was performed to identify phenotypes of radiographic knee OA progression. The phenotypes identified were compared for changes in joint space width (JSW), varus angle, osteophyte area, eminence height, bone density, for Kellgren-Lawrence (K-L) grade, and for clinical characteristics. Logistic regression analysis evaluated whether baseline radiographic features and demographic/clinical characteristics were associated with each of the specific phenotypes.

RESULTS

The 5 clusters identified were interpreted as "Severe" or "No," "Early" or "Late" progression of the radiographic features, or specific involvement of "Bone density." Medial JSW, varus angle, osteophyte area, eminence height, and bone density at baseline were associated with the Severe and Bone density phenotypes. Lesser eminence height and bone density were associated with Early and Late progression. Larger varus angle and smaller osteophyte area were associated with No progression.

CONCLUSION

Five phenotypes of radiographic progression of early knee OA were identified using separate quantitative features, which were associated with baseline radiographic features. Such phenotypes might require specific treatment and represent relevant subgroups for clinical trials.

Neurophysiology of arthritis pain

Arthritis pain is a complex phenomenon involving intricate neurophysiological processing at all levels of the pain pathway. The treatment options available to alleviate joint pain are fairly limited and most arthritis patients report only modest pain relief with current treatments. A better understanding of the neural mechanisms responsible for musculoskeletal pain and the identification of new targets will help in the development of future pharmacological therapies. This article reviews some of the latest research into factors which contribute to joint pain and covers areas such as cannabinoids, proteinase activated receptors, sodium channels, cytokines and transient receptor potential channels. The emerging hypothesis that osteoarthritis may have a neuropathic component is also discussed.

Neural and psychosocial contributions to sex differences in knee osteoarthritic pain

People with osteoarthritis (OA) can have significant pain that interferes with function and quality of life. Women with knee OA have greater pain and greater reductions in function and quality of life than men. In many cases, OA pain is directly related to sensitization and activation of nociceptors in the injured joint and correlates with the degree of joint effusion and synovial thickening. In some patients, however, the pain does not match the degree of injury and continues after removal of the nociceptors with a total joint replacement. Growth of new nociceptors, activation of nociceptors in the subchondral bone exposed after cartilage degradation, and nociceptors innervating synovium sensitized by inflammatory mediators could all augment the peripheral input to the central nervous system and result in pain. Enhanced central excitability and reduced central inhibition could lead to prolonged and enhanced pain that does not directly match the degree of injury. Psychosocial variables can influence pain and contribute to pain variability. This review explores the neural and psychosocial factors that contribute to knee OA pain with an emphasis on differences between the sexes and gaps in knowledge.

Pain in patients with equal radiographic grades of osteoarthritis in both knees: the value of gray scale ultrasound

OBJECTIVES

To investigate the association of ultrasound (US) features with pain and the functional scores in patients with equal radiographic grades of osteoarthritis (OA) in both knees.

METHODS

Fifty-six consecutive patients with knee OA: 85 symptomatic knees (81 knees with medial pain) and 27 asymptomatic knees, and 10 healthy patients without knee OA as a control were enrolled. US was done by two ultrasonographers blinded to patient diagnoses. US features were semiquantitatively scored (0-3) when appropriate.

RESULTS

In the OA group, common US findings were marginal osteophyte, suprapatellar synovitis, suprapatellar effusion (SPE), medial meniscus protrusion, medial compartment synovitis (MCS), lateral compartment synovitis, and Baker's cyst. Only SPE and MCS were significantly associated with knee pain. Visual analog pain scale (VAS) scores on motion were positively linearly associated with SPE and MCS (P < 0.01). Only MCS was degree-dependently associated with VAS scores at rest, the Western Ontario and McMaster Universities pain subscale, and the presence of medial knee pain (P < 0.01) after adjustments for age, gender, body mass index (BMI), radiographic grade, and other US features. In the control group, no US features were associated with knee pain.

CONCLUSIONS

US inflammation features, including SPE and MCS, were positively linearly associated with knee pain in motion. MCS was also degree-dependently associated with pain at rest and the presence of medial knee pain. These findings show that synovitis was one important predictive factor of pain. Further studies to confirm the association of US features and pain are warranted.

Relationships between Pain, Function and Radiographic Findings in Osteoarthritis of the Knee: A Cross-Sectional Study

Objectives. The aim of this study was to investigate the relationships between pain, disability, and radiographic findings in patients with knee osteoarthritis (OA). Patients and Methods. A total of 114 patients with knee OA who attended the physical medicine and rehabilitation outpatient clinic were included in this study. The diagnosis was based on the American College of Rheumatology (ACR) criteria for knee OA. Age, duration of disease, and body mass index (BMI) of the patients were recorded. Radiographic features on the two-sided knee radiography were assessed with the Kellgren-Lawrence scale. The severity of knee pain, stiffness, and disability were measured using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Results. The mean age of the patients was 56.98 (±8.28) years and the mean disease duration was 4.14 (±4.15) years. Kellgren-Lawrence grading scale and age or disease duration were positively and significantly associated, whereas none of the WOMAC subscores were found to be related with Kellgren-Lawrence grading scale (P > 0.05). On the other hand, WOMAC disability scores were significantly associated with WOMAC pain and WOMAC stiffness (P < 0.01). Conclusions. Knee pain, stiffness, and duration of disease may affect the level of disability in the patients with knee OA. Therefore treatment of knee OA could be planned according to the clinical features and functional status instead of radiological findings.

Quantitative sensory testing in painful osteoarthritis: a systematic review and meta-analysis

OBJECTIVE

To systematically review the use of quantitative sensory testing (QST) in pain characterisation (phenotyping) in osteoarthritis (OA).

METHODS

Six bibliographic databases (Medline, Embase, Amed, Cinahl, PubMed, Web of Science) were searched to identify studies published before May 2011. Data were extracted based on the primary site of OA, QST modalities, outcome measures and test sites. Standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated if possible. Publication bias was determined using funnel plot and Egger's test. Heterogeneity was examined using Cochran Q test and I2 statistic. Random effects model was used to pool the results.

RESULTS

Of 41 studies (2281 participants) included, 23 were case control studies, 15 case only studies, two randomised controlled trials, and one uncontrolled trial. The majority of studies examined pressure pain with smaller numbers using electrical and/or thermal stimuli. QST was more often applied to the affected joint than distal and remote sites. Of 20 studies comparing people with OA and healthy controls, seven provided sufficient information for meta-analysis. Compared with controls, people with OA had lower pressure pain thresholds (PPTs) both at the affected joint (SMD = -1.24, 95% CI -1.54, -0.93) and at remote sites (SMD = -0.88, 95% CI -1.11, -0.65).

CONCLUSION

QST of PPTs demonstrated good ability to differentiate between people with OA and healthy controls. Lower PPTs in people with OA in affected sites may suggest peripheral, and in remote sites central, sensitisation. PPT measurement merits further evaluation as a tool for phenotyping OA pain.

The value of preoperative grade of radiographic and histological changes in predicting pain relief after total knee arthroplasty for osteoarthritis

PURPOSE

Many attempts with contradictory results have been made to correlate different features of OA with pain. One reason may be that pain at rest and pain with movement are seldom considered separately although the mechanisms may be quite different. Furthermore, pain ratings are subject to individual interpretation making an inter-individual comparison questionable. By instead calculating the absolute and relative changes in pain on an intra-individual level after total knee arthroplasty (TKA), we aimed at exploring a relationship between pain and radiological and histological changes.

METHODS

In 69 patients undergoing TKA, preoperative radiographs and perioperative histological samples of the synovial membrane were graded for severity of osteoarthritic and inflammatory changes. The findings were related to the intensity of pain at rest and with movement both preoperatively and 18 months postoperatively according to the visual analogue scale (VAS).

RESULTS

The radiographic and histological findings showed no significant correlation with the mean pre- or postoperative pain scores. Instead, change in pain with movement from pre- to postoperative was significantly related to the grade of radiographic osteoarthritis. Best pain relief by TKA was achieved in patients with severe radiographic changes. This, however, only applied to pain with movement.

CONCLUSIONS

Pain at rest and pain with movement may have different mechanisms. We believe that assessing the intensity of pain at rest and pain with movement separately and considering changes in pain on an individual level will be helpful strategies in future follow-up studies and efforts aimed at explaining the mechanisms of pain in OA.

COMPARING QUALITY OF LIFE AMONG PEOPLE WITH DIFFERENT PATTERNS AND SEVERITIES OF KNEE OSTEOARTHRITIS

Objective: To identify what extent different patterns and severities of involvement affect quality of life of people suffering knee osteoarthritis.

Methods: This population-based survey involved 288 women and 288 men aged 40 years or older from Songkhla province, southern Thailand. Quality of life was measured using the Medical Outcome Study Short Form Health sutvery (SF-36) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic investigation included antero-posterior and skyline view of both knees. Osteoarthritis was categorized into 3 patterns; isolated patellofemoral, isolated tibiofemoral and combined with diagnosis based on Kellgren & Lawrence grade 2 or higher.

Results: Quality of life as measured by SF-36 and WOMAC showed poorer score in moderate or severe grade than in mild grade of severity. Isolated patellofemoral and combined patterns demonstrated showed poorer scores on both WOMAC and SF-36 than isolated tibiofemoral pattern. Body mass index, income level and pattern of involvement could independently predict total scores of WOMAC, while age, marital status and pattern of involvement affected total score of SF-36.

Conclusion: Pattern of involvement is a better predictor of quality of life than disease severity in patients with knee osteoarthritis.

OARSI/OMERACT initiative to define states of severity and indication for joint replacement in hip and knee osteoarthritis. An OMERACT 10 Special Interest Group

OBJECTIVE

To define pain and physical function cutpoints that would, coupled with structural severity, define a surrogate measure of "need for joint replacement surgery," for use as an outcome measure for potential structure-modifying interventions for osteoarthritis (OA).

METHODS

New scores were developed for pain and physical function in knee and hip OA. A cross-sectional international study in 1909 patients was conducted to define data-driven cutpoints corresponding to the orthopedic surgeons' indication for joint replacement. A post hoc analysis of 8 randomized clinical trials (1379 patients) evaluated the prevalence and validity of cutpoints, among patients with symptomatic hip/knee OA.

RESULTS

In the international cross-sectional study, there was substantial overlap in symptom levels between patients with and patients without indication for joint replacement; indeed, it was not possible to determine cutpoints for pain and function defining this indication. The post hoc analysis of trial data showed that the prevalence of cases that combined radiological progression, high level of pain, and high degree of function impairment was low (2%-12%). The most discriminatory cutpoint to define an indication for joint replacement was found to be [pain (0-100) + physical function (0-100) > 80].

CONCLUSION

These results do not support a specific level of pain or function that defines an indication for joint replacement. However, a tentative cutpoint for pain and physical function levels is proposed for further evaluation. Potentially, this symptom level, coupled with radiographic progression, could be used to define "nonresponders" to disease-modifying drugs in OA clinical trials.

Does diabetes hide osteoarthritis pain?

Clinical practice and research efforts related to the highly prevalent and disabling disease, osteoarthritis (OA), have long been hampered by an inadequate case definition. Much of the difficulty is due to a lack of agreement between X-rays evidence of OA and a patient's report of pain at that site. Such discordance between reported pain and radiographic evidence of OA has been attributed to several factors. This paper proposes another possible explanation, for at least a portion of such patients. It is hypothesized that an insidiously increasing diabetic neuropathy, particularly in the lower extremity, while first causing some pain, may gradually inhibit the ability to feel pain which might have otherwise been reported by those patients without neuropathy. Many of these patients with early stage glucose dysmetabolism will proceed to develop overt type 2 diabetes; however, the pain-inhibiting neuropathy caused by glucose metabolism dysfunction may manifest long before such a diagnosis. The high prevalence of diabetes and pre-diabetic conditions, especially among the aged population, could mean that a substantial number of individuals with osteoarthritis will have both diseases to varying degrees over time. Validating and quantifying this hypothesized association would be useful to millions of persons and would significantly impact both research and clinical practice dealing with these major diseases of older persons.

Association between pain, radiographic severity, and centrally-mediated symptoms in women with knee osteoarthritis

OBJECTIVE

To examine the relationship between pain, radiographic severity, and a common set of co-occurring centrally-mediated symptoms (fatigue, sleep quality, and depression) in women with knee osteoarthritis.

METHODS

Participants underwent knee radiographs, and had repeated assessments of pain severity and other centrally-mediated symptoms during a 5-day home monitoring period. To examine associations between pain severity (the average of pain over the home monitoring period), measures of osteoarthritis radiographic severity (Kellgren/Lawrence grade, minimum joint space width), centrally-mediated symptoms, and demographics (age) were used. Symptoms of fatigue, sleep efficiency, and depression were used in a composite measure representing centrally-mediated symptoms.

RESULTS

Using a series of linear regression models in which each variable was entered hierarchically (n = 54), the final model showed that 27% of the variance in pain severity was explained by age, radiographic severity, and centrally-mediated symptoms. Centrally-mediated symptoms explained an additional 10% of the variance in pain severity after the other 2 variables were entered.

CONCLUSION

Both radiographic severity and centrally-mediated symptoms were independently and significantly associated with pain severity in women with knee osteoarthritis. In addition to more severe radiographic features, women with higher centrally-mediated symptoms had greater pain severity. Treatments for women with symptomatic knee osteoarthritis may be optimized by addressing both peripheral and central sources of pain.

The radiographic predictors of symptom severity in advanced knee osteoarthritis with varus deformity

Information concerning the abilities of radiographic parameters to predict the symptoms of advanced osteoarthritis (OA) of the knee would be valuable, because plain knee radiographs are used as one of the primary tools for the selection of treatment modalities. We aimed to identify the radiographic predictors of symptom severity in patients with varus knee OA advanced enough to warrant total knee arthroplasty (TKA). In 341 knees with primary varus OA warranting TKA, pertinent radiographic features of the medial and lateral tibiofemoral joint (TFJ), and the patellofemoral joint (PFJ) were assessed separately and scored. In addition, TF alignment was assessed on standing full-limb radiographs. Symptoms and functions were evaluated using WOMAC pain and function scores. In the univariate analyses with generalized estimating equations (GEE), multiple radiographic features (subluxation of the TFJ, overall severity of the medial TFJ, and degree of TF varus alignment) were associated with poorer WOMAC function scores, whereas only the degree of TF varus alignment was associated with poorer WOMAC pain scores. None of radiographic parameters in the PFJ or lateral TFJ (except TFJ subluxation) was associated with WOMAC scores. Multivariate analyses revealed that the degree of TF varus alignment was the strongest predictor of poorer WOMAC pain and function scores. We propose that extent of TF varus malalignment should be considered as the primary indicator of objective disease severity when selecting treatment options for patients with advanced knee OA.