Does gabapentin provide benefit for patients with knee OA? A benefit-harm and cost-effectiveness analysis

OBJECTIVE

Gabapentin can treat neuropathic pain syndromes and has increasingly been prescribed to treat nociplastic pain. Some patients with knee osteoarthritis (OA) suffer from both nociceptive and nociplastic pain. We examined the cost-effectiveness of adding gabapentin to knee OA care.

METHOD

We used the Osteoarthritis Policy Model, a validated Monte Carlo simulation of knee OA, to examine the value of gabapentin in treating knee OA by comparing three strategies: 1) usual care, gabapentin sparing (UC-GS); 2) targeted gabapentin (TG), which provides gabapentin plus usual care for those who screen positive for nociplastic pain on the modified PainDETECT questionnaire (mPD-Q) and usual care only for those who screen negative; and 3) universal gabapentin plus usual care (UG). Outcomes included cumulative quality-adjusted life years (QALYs), lifetime direct medical costs, and incremental cost-effectiveness ratios (ICERs), discounted at 3% annually. We derived model inputs from published literature and national databases and varied key input parameters in sensitivity analyses.

RESULTS

UC-GS dominated both gabapentin-containing strategies, as it led to lower costs and more QALYs. TG resulted in a cost increase of $689 and a cumulative QALY reduction of 0.012 QALYs. UG resulted in a further $1,868 cost increase and 0.036 QALY decrease. The results were robust to plausible changes in input parameters. The lowest TG strategy ICER of $53,000/QALY was reported when mPD-Q specificity was increased to 100% and AE rate was reduced to 0%.

CONCLUSION

Incorporating gabapentin into care for patients with knee OA does not appear to offer good value.

Exercise and education vs intra-articular saline for knee osteoarthritis: a 1-year follow-up of a randomized trial

OBJECTIVE

To assess the longer-term effect of the Good Life with osteoarthritis in Denmark (GLAD) exercise and education program relative to open-label placebo (OLP) on changes from baseline in core outcomes in individuals with knee osteoarthritis (OA).

METHODS

In this 1-year follow-up of an open-label, randomized trial, patients with symptomatic and radiographically confirmed knee OA were monitored after being randomized to either the 8-week GLAD program or OLP given as 4 intra-articular saline injections over 8 weeks. The primary outcome was the change from baseline in the Knee injury and Osteoarthritis Outcome Score questionnaire (KOOS) pain subscale after 1 year in the intention-to-treat population. Key secondary outcomes were the KOOS function and quality of life subscales, and Patients' Global Assessment of disease impact.

RESULTS

206 adults were randomly assigned: 102 to GLAD and 104 to OLP, of which only 137 (63/74 GLAD/OLP) provided data at 1 year. At one year the mean changes in KOOS pain were 8.4 for GLAD and 7.0 for OLP (Difference: 1.5 points; 95% CI -2.6 to 5.5). There were no between-group differences in any of the secondary outcomes.

CONCLUSIONS

In this 1-year follow-up of individuals with knee OA, the 8-week GLAD program and OLP both provided minor longer-term benefits with no group difference. These results require confirmation given the significant loss to follow-up.

TRIAL REGISTRATION NUMBER

NCT03843931.

Osteoarthritis Bone Marrow Lesions

Assessment and treatment of Bone Marrow Lesions (BMLs) could ultimately make step changes to the lives of people with osteoarthritis (OA). We here review the imaging and pathological characteristics of OA-BMLs, their differential diagnosis and measurement, and cross-sectional and longitudinal associations with pain and OA structural progression. We discuss how biomechanical and cellular factors may contribute to BML pathogenesis, and how pharmacological and non-pharmacological interventions that target BMLs might reduce pain and OA structural progression. We critically appraise semiquantitative and quantitative methods for assessing BMLs, and their potential utilities for identifying people at risk of symptomatic and structural OA progression, and evaluating treatment responses. New interventions that target OA-BMLs should both confirm their importance, and reduce the unacceptable burden of OA.

Who are likely to benefit from the Good Life with osteoArthritis in Denmark (GLAD) exercise and education program? An effect modifier analysis of a randomised controlled trial

OBJECTIVE

To identify contextual factors that modify the treatment effect of the 'Good Life with osteoArthritis in Denmark' (GLAD) exercise and education programme compared to open-label placebo (OLP) on knee pain in individuals with knee osteoarthritis (OA).

METHODS

Secondary effect modifier analysis of a randomised controlled trial. 206 participants with symptomatic and radiographic knee OA were randomised to either the 8-week GLAD programme (n = 102) or OLP given as 4 intra-articular saline injections over 8 weeks (n = 104). The primary outcome was change from baseline to week 9 in the Knee injury and Osteoarthritis Outcome Score questionnaire (KOOS) pain subscale (range 0 (worst) to 100 (best)). Subgroups were created based on baseline information: BMI, swollen study knee, bilateral radiographic knee OA, sports participation as a young adult, sex, median age, a priori treatment preference, regular use of analgesics (NSAIDs or paracetamol), radiographic disease severity, and presence of constant or intermittent pain.

RESULTS

Participants who reported use of analgesics at baseline seem to benefit from the GLAD programme over OLP (subgroup contrast: 10.3 KOOS pain points (95% CI 3.0 to 17.6)). Participants with constant pain at baseline also seem to benefit from GLAD over OLP (subgroup contrast: 10.0 points (95% CI 2.8 to 17.2)).

CONCLUSIONS

These results imply that patients who take analgesics or report constant knee pain, GLAD seems to yield clinically relevant benefits on knee pain when compared to OLP. The results support a stratified recommendation of GLAD as management of knee OA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03843931. EudraCT number 2019-000809-71.

Effectiveness of vitamin D supplementation on knee osteoarthritis - A target trial emulation study using data from the Osteoarthritis Initiative cohort

OBJECTIVE

To assess the real-world effectiveness of vitamin D supplementation in patients with knee osteoarthritis (KOA) by replicating a randomized controlled trial (RCT) design in an observational study.

METHOD

This study emulated a target trial using data from the Osteoarthritis Initiative (OAI). Eligible participants were ≥45 years, had symptomatic KOA and did not take vitamin D supplements in the past 30 days. A participant can enter the trial more than once. Participants were included in vitamin D group if they took ≥1,000 IU/day for ≥4 days/week in the past 30 days at the first follow-up visit after baseline. The control group did not use vitamin D in the past 30 days. Optimal propensity score matching at 1:1 ratio was performed. The primary outcome was change in knee pain 2 years after baseline measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes included WOMAC physical function and quantitative joint space width (JSW). Standardized mean difference (SMD) was used to compare the findings with previous RCTs.

RESULTS

A total of 236 person-trials in the vitamin D group were pair-matched with a control. Compared to the control group, vitamin D supplementation did not reach significant changes in WOMAC pain (SMD = -0.04, 95%CI [-0.21, 0.13]), physical function and radiographic JSW over 2 years. The SMDs were consistent with the effect sizes reported in previous RCTs.

CONCLUSION

Target trial emulation in the OAI cohort demonstrated findings close to published RCTs. This supports the future use of target trial emulation in evaluating other systemic therapies for KOA.

Synovitis mediates the association between bone marrow lesions and knee pain in osteoarthritis: data from the Foundation for the National Institute of Health (FNIH) Osteoarthritis Biomarkers Consortium

OBJECTIVES

Although subchondral bone marrow lesions (BMLs) and synovitis have been well acknowledged as important sources of pain in knee osteoarthritis (KOA), it is unclear if synovitis plays the mediating role in the relationship between BMLs and knee pain.

METHODS

We analyzed 600 subjects with magnetic resonance imaging (MRI) in the Foundation for National Institutes of Health Osteoarthritis Biomarkers Consortium (FNIH) cohort at baseline and 24-month. BMLs and synovitis were measured according to the MRI Osteoarthritis Knee Score (MOAKS) scoring system. BMLs were scored in five subregions. A summary synovitis score of effusion and Hoffa-synovitis was calculated. Knee pain was evaluated using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Linear regression models were applied to analyze the natural direct effect (NDE) of BMLs and synovitis with knee pain, respectively, and natural indirect effect (NIE) mediated by synovitis.

RESULTS

590 participants (58.8% females, with a mean age of 61.5) were included in the present analyses. For NDE, knee pain was cross-sectionally associated with medial femorotibial BMLs (β = 0.23, 95% CI: 0.09, 0.38) and synovitis (β = 0.40, 95% CI: 0.20, 0.60). Longitudinal associations retained significant [medial femorotibial BMLs (β = 0.37, 95% CI: 0.21, 0.53); synovitis (β = 0.72, 95% CI: 0.45, 0.99)]. In the NIE analyses, synovitis mediated the association between medial femorotibial BML and knee pain at baseline (β = 0.051, 95% CI: 0.01, 0.09) and over 24 months (β = 0.079, 95% CI: 0.023, 0.15), with the mediating proportion of 17.8% and 22.4%, respectively.

CONCLUSION

Synovitis partially mediates the association between medial femorotibial BMLs and knee pain.

Development and validation of the Flare-OA questionnaire for measuring flare in knee and hip osteoarthritis

OBJECTIVE

Ability to assess flares in osteoarthritis (OA) of the knee and hip (KHOA) is important in clinical care and research. Using mixed methods, we developed a self-reported instrument measuring flare and assessed its psychometric properties.

METHODS

We constructed questionnaire items from semi-structured interviews and a focus group (patients, clinicians) by using a dual-language (English-French) approach. A Delphi consensus method was used to select the most relevant items. Patients with OA from Australia, France and the United States completed the preliminary Flare-OA, HOOS, KOOS and Mini-OAKHQOL questionnaires online. We used a factor analysis and content approach to reduce items and determine structural validity. We tested the resulting questionnaire (score 0-100) for internal consistency, convergent and known-groups validity.

RESULTS

Initially, 180 statements were generated and reduced to 33 items in five domains (response 0 = not at all, to 10 = absolutely) by Delphi consensus (50 patients, 116 professionals) and an expert meeting. After 398 patients (mean [SD] age 64 [8.5] years, 70.4% female, 86.7% knee OA) completed the questionnaire, it was reduced to 19 items by factor analysis and a content approach (RMSEA = 0.06; CFI = 0.96; TLI = 0.94). The Cronbach's alpha was >0.9 for the five domains and the whole questionnaire. Correlation coefficients between Flare-OA and other instrument scores were as predicted, supporting construct validity. The difference in Flare-OA score between patients with and without flare (31.8) largely exceeded 2 SEM (10.2).

CONCLUSION

Flare-OA is a valid and reliable patient-reported instrument for assessing the occurrence and severity of flare in patients with KHOA in clinical research.

Greater efficacy of a combination of conservative therapies for thumb base OA in individuals with lower radial subluxation - a pre-planned subgroup analysis of the COMBO trial

OBJECTIVE

To investigate heterogeneous effects of a combination of conservative therapies compared with an education comparator for thumb base (TB) osteoarthritis (OA) according to clinically relevant characteristics.

METHODS

Pre-planned subgroup analysis of the COMBO trial (n = 204) which compared a combination of education on self-management and ergonomic principles, a prefabricated neoprene splint, hand exercises, and diclofenac sodium gel, with education alone for radiographic and symptomatic TB OA. Primary outcomes were change in pain (visual analogue scale [VAS], 0-100 mm) and hand function (Functional Index for Hand Osteoarthritis questionnaire, 0-30) from baseline to week-6. Other outcomes were grip and tip-pinch strength and patient's global assessment (PGA) (VAS, 0-100 mm). Possible treatment effect modifiers were the presence of interphalangeal joint pain, erosive hand OA, radiographic thumb carpometacarpal joint subluxation (higher vs equal or lower than the sample mean), and baseline radiographic OA severity (Kellgren Lawrence grade). Linear regression models were fitted, adding interaction terms for each subgroup of interest.

RESULTS

The treatment effects of the combined intervention at 6 weeks were greater in participants with lower joint subluxation compared with those with greater subluxation (pain -11.6 [95%CI -22.2, -9.9] and 2.6 [-5.5, 10.7], respectively, difference between the subluxation groups 14.2 units (95% CI 2.3, 26.1), p-value 0.02; and PGA -14.0 [-22.4, -5.5] and 1.5 [-6.2, 9.3), respectively, difference between the subluxation groups 15.5 units (95% CI 4.2, 26.8), p-value 0.03). There was no statistically significant heterogeneity for the other subgroups.

CONCLUSION

A combination of conservative therapies may provide greater benefits over 6 weeks in individuals with lower joint subluxation, although the clinical relevance is uncertain given the wide confidence intervals. Treatment strategies may need to be customized for those with greater joint subluxation.

TRIAL REGISTRATION NUMBER

ACTRN 12616000353493.

The art and science of priority-setting: assessing the value of Public Health England's Prioritization Framework

BACKGROUND

Findings are presented from the evaluation of Public Health England's (PHE) Prioritization Framework (PF) aimed to assist local authority commissioners with their public health investment and disinvestment decisions. The study explored the take up of the PF in three early adopter local authority settings.

METHODS

Semi-structured interviews (n = 30) across three local authorities supplemented by participant observation of workshops.

RESULTS

Participants acknowledged that the PF provided a systematic means of guiding priority-setting and one that encouraged transparency over investment and disinvestment decisions. The role performed by PHE and its regional teams in facilitating the process was especially welcomed and considered critical to the adoption process. However, uptake of the PF required a significant investment of time and commitment from public health teams at a time when resources were stretched. The impact of the political environment in the local government was a major factor determining the likely uptake of the PF. Ensuring committed leadership and engagement from senior politicians and officers was regarded as critical to success.

CONCLUSIONS

The study assessed the value and impact of PHE's PF tool in three early adopter local authorities. Further research could explore the value of the tool in aiding investment and disinvestment decisions and its impact on spending.

Efficacy and safety of a supplement combination on hand pain among people with symptomatic hand osteoarthritis an internet-based, randomised clinical trial the RADIANT study

OBJECTIVE

The RADIANT study aimed to investigate the efficacy and safety of a complementary medicine supplement combination in people with hand osteoarthritis (HOA).

METHOD

This was an internet-based, double-blind, randomised, placebo-controlled trial. Participants aged over 40 years with symptomatic HOA with radiographic confirmation (Kellgren Lawrence grade ≥ 2) throughout Australia were recruited and randomly assigned (1:1) to receive either a supplement combination composed of Boswellia serrata extract 250 mg/day, pine bark extract 100 mg/day, methylsulfonylmethane 1,500 mg/day and curcumin 168 mg/day or placebo for 12 weeks. The primary outcome was change in hand pain assessed using a visual analogue scale (VAS 0-100) from baseline to week 12. A range of secondary outcomes and additional measures were recorded. Adverse events were monitored weekly.

RESULTS

One hundred and six participants were included with mean age 65.6 years and 81% were women. 45% of the participants were graded as KLG 4, 40% KLG three and 39 (37%) had erosive OA. There was no significant difference in pain VAS reduction between groups. The adjusted between group difference in means (95%CI) was 5.34 (-2.39 to 13.07). Five participants (10%) in the supplement combination group discontinued study treatment due to AE vs four participants (7%) in the placebo group.

CONCLUSION

There were no significant differences in symptomatic relief between the two groups over 12 weeks. These findings do not support the use of the supplement combination for treating hand pain in people with HOA.

REGISTRATION

Prospectively registered (Australian New Zealand Clinical Trials Registry ACTRN12619000835145, 31/05/2019).

Can pain flares in knee osteoarthritis be predicted?

Objectives: This study examined whether risk factors for knee osteoarthritis (KOA) pain such as age, gender, body mass index (BMI), baseline pain, and other putative risk factors for knee osteoarthritis pain flares (KOAF) (e.g. knee buckling, injury, mood/stress/social support scores, and footwear) could predict KOAF.Method: People with KOA and previous history of KOAF were selected from a 3 month web-based longitudinal study. KOAF was defined as an increase of ≥ 2 points on a numeric rating scale (compared with background pain) which resolved within 20 days. Predictors assessed at baseline were gender, age, duration of KOA, BMI, pain, knee injury (7 days before), knee buckling (2 days before), Lubben Social Support, Knee Injury and Osteoarthritis Outcome Score, Intermittent and Constant Osteoarthritis Pain score (ICOAP), Positive/Negative Affect Score, and footwear stability/heel height. Outcome was occurrence of any KOAF during the ensuing 30 days. The combined ability of the above variables to predict occurrence of any KOAF was evaluated by multiple logistic regression with a 10-fold cross-validation method to build and internally validate the model. Variables that assessed similar domains were eliminated using receiver operating characteristics curve assessment for best fit.Results: Complete data were available for 313 people (66.6% female, mean ± sd age 62.3 ± 8.2 years, BMI 29.7 ± 6.5 kg/m²). Increasing age, years of osteoarthritis, BMI, background/worst levels of pain, knee injury, knee buckling, ICOAP, and footwear category/heel height significantly predicted the occurrence of KOAF during the following 30 days, with an area under the curve of 0.73 (95% confidence interval 0.67-0.80).Conclusion: A combination of risk factors assessed at baseline, including exposures with potential to vary, successfully predicts the KOAF in the ensuing 30 days.

Cost-effectiveness of duloxetine for knee OA subjects: the role of pain severity

OBJECTIVE

Establish the impact of pain severity on the cost-effectiveness of generic duloxetine for knee osteoarthritis (OA) in the United States.

DESIGN

We used a validated computer simulation of knee OA to compare usual care (UC) - intra-articular injections, opioids, and total knee replacement (TKR) - to UC preceded by duloxetine in those no longer achieving pain relief from non-steroidal anti-inflammatory drugs (NSAIDs). Outcomes included quality-adjusted life years (QALYs), lifetime medical costs, and incremental cost-effectiveness ratios (ICERs). We considered cohorts with mean ages 57-75 years and Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain 25-55 (0-100, 100-worst). We derived inputs from published data. We discounted costs and benefits 3% annually. We conducted sensitivity analyses of duloxetine efficacy, duration of pain relief, toxicity, and costs.

RESULTS

Among younger subjects with severe pain (WOMAC pain = 55), duloxetine led to an additional 9.6 QALYs per 1,000 subjects (ICER = $88,500/QALY). The likelihood of duloxetine being cost-effective at willingness-to-pay (WTP) thresholds of $50,000/QALY and $100,000/QALY was 40% and 54%. Offering duloxetine to older patients with severe pain led to ICERs >$150,000/QALY. Offering duloxetine to subjects with moderate pain (pain = 25) led to ICERs <$50,000/QALY, regardless of age. Among knee OA subjects with severe pain (pain = 55) who are unwilling or unable to undergo TKR, ICERs were <$50,600/QALY, regardless of age.

CONCLUSIONS

Duloxetine is a cost-effective addition to knee OA UC for subjects with moderate pain or those with severe pain unable or unwilling to undergo TKR. Among younger subjects with severe pain, duloxetine is cost-effective at WTP thresholds >$88,500/QALY.

Association of weather factors with the risk of pain exacerbations in people with hip osteoarthritis

Objectives: Our objective was to evaluate the association of weather factors with the risk of pain exacerbations in people with symptomatic hip osteoarthritis (OA). Method: Eligible participants with symptomatic hip OA were instructed to log on to the study website and complete questionnaires every 10 days and additionally whenever they considered they were experiencing a pain exacerbation (case period) during the 90 day follow-up. Pain exacerbation was defined as an increase of two points in pain intensity on an 11-point numeric rating scale (0-10) during the follow-up compared with baseline. Each case period was anchored to four control periods within a 35 day interval using a time-stratified approach. Weather data were obtained for both periods from the publicly available meteorological database of the Australian Bureau of Meteorology. We examined the association of weather factors across 72 h before the index date with the risk of pain exacerbation, using conditional logistic regression. Results: Among 252 participants recruited, 129 participants had at least one episode of pain exacerbation and were included in the analysis. A significant dose-response relationship was found between average daily temperature variation in the prior 72 h and risk of pain exacerbations (p = 0.04 for linear trend). There was no significant association between maximum daily temperature, minimum daily temperature, relative humidity, precipitation, or barometric pressure and hip pain exacerbations. Conclusion: The overall results suggest that only daily temperature variation among different weather factors was associated with hip pain exacerbations in people with symptomatic hip OA.

Association of baseline and change in tibial and femoral cartilage thickness and development of widespread full-thickness cartilage loss in knee osteoarthritis - data from the Osteoarthritis Initiative

OBJECTIVE

To investigate whether baseline cartilage thickness and its longitudinal change are associated with incident widespread full-thickness cartilage loss (wsFTCL) in knee osteoarthritis, and whether there are optimal cut-off values for predicting wsFTCL.

METHODS

Central medial tibial (cMT) and femoral (cMF) cartilage were assessed using quantitative magnetic resonance imaging data from the Osteoarthritis Initiative cohort (N = 600 knees). Cartilage thickness was measured at baseline and 12 months. wsFTCL was defined semi-quantitatively (scores 2 and 3 from the MRI Osteoarthritis Knee Score) and its incidence at 24 months recorded. Logistic regression was used to determine the odds of developing wsFTCL for baseline and for each 0.1 mm decrease in cartilage thickness. Cut-off values were investigated using the minimal-p method and area under the Receiver Operating Characteristic curves (AUC).

RESULTS

Incident wsFTCL was observed in 66 (12%) and 73 (14%) knees in cMT and cMF, respectively. Lower baseline cMT and cMF cartilage thickness values were associated with wsFTCL (OR = 1.20; 95% CI: 1.11, 1.28 and OR = 1.15; 95% CI: 1.06 to 1.24, respectively). Optimal cut-off AUCs for the tibia and femur were 0.64 (0.57-0.70) and 0.63 (0.57-0.69), respectively. Longitudinal decrease in femoral, but not tibial, cartilage thickness was associated with incident wsFTCL (OR = 1.77; 95% CI: 1.30 to 2.40); optimal cut-off AUC 0.65 (95% CI: 0.58-0.72).

CONCLUSION

Lower baseline cMT and baseline/change (decrease) over 12 months in cMF cartilage thickness were associated with incident, location-specific, wsFTCL at 24 months. Optimal cut-off values were relatively low and of uncertain utility for predicting incident wsFTCL.

Long-term clinical and economic outcomes of a short-term physical activity program in knee osteoarthritis patients

OBJECTIVE

Physical activity (PA) in the US knee osteoarthritis (OA) population is low, despite well-established health benefits. PA program implementation is often stymied by sustainability concerns. We sought to establish parameters that would make a short-term (3-year efficacy) PA program a cost-effective component of long-term OA care.

METHOD

Using a validated computer microsimulation (Osteoarthritis Policy Model), we examined the long-term clinical (e.g., comorbidities averted), quality of life (QoL), and economic impacts of a 3-year PA program, based upon the SPARKS (Studying Physical Activity Rewards after Knee Surgery) Trial, for inactive knee OA patients. We determined the cost, efficacy, and impact of PA on QoL and medical costs that would make a PA program a cost-effective addition to OA care.

RESULTS

Among the 14 million with knee OA in the US, >4 million are inactive. Participation of 10% in the modeled PA program could save 200 cases of cardiovascular disease, 400 cases of diabetes, and 6,800 quality-adjusted life-years (QALYs). The program had an incremental cost-effectiveness ratio (ICER) of $16,100/QALY. Tripling PA program cost ($860/year) raised the ICER to $108,300/QALY; varying QoL benefits from PA yielded ICERs of $8,800/QALY-$99,900/QALY; varying background cost savings from PA did not qualitatively impact ICERs. Offering the PA program to any adults with knee OA (not only inactive) yielded $31,000/QALY.

CONCLUSION

A PA program with 3-year efficacy in the knee OA population carried favorable long-term clinical and economic benefits. These results offer justification for policymakers and payers considering a PA intervention incorporated into knee OA care.

Is the Patient Activation Measure a valid measure of osteoarthritis self-management attitudes and capabilities? Results of a Rasch analysis

BACKGROUND

The Patient Activation Measure (PAM-13) was developed using Rasch analysis to assess knowledge, skills and confidence in the management of one's health. Previous studies report positive relationships between PAM-13 scores, self-management behaviours and longitudinal health outcomes in adults with chronic disease. There is little extant measurement property evidence for the use of PAM-13 in specific osteoarthritis (OA) populations. This study tested measurement properties of the PAM-13 in people living with hip and knee OA.

METHODS

Item response frequency analysis was conducted. Rasch analysis evaluated the fit of the PAM-13 data to the Rasch model. Model-data fit was evaluated using infit and outfit statistics; person/item reliability and person separation indices were computed. Unidimensionality was evaluated using Principal Components Analysis of Rasch residuals and the data were assessed for item redundancy. Differential Item Functioning (DIF) examined bias in respondent subgroups and correlations tested relationships between PAM-13 and other patient-reported outcomes.

RESULTS

Two-hundred-and-seventeen PAM-13 surveys were completed; there were no missing responses, floor or ceiling effects. Person and item reliability were acceptable (0.98 and 0.87 respectively) with good separation (person separation index 2.58). Unidimensionality was evaluated, with 49.4% of the variance explained by the first eigenvector. There was evidence of potential local response-dependence. The Rasch fit statistics were acceptable (except for item-2). There were some issues identified with targeting of the PAM-13 items to people with higher ability and the item difficulty order was different to that proposed in original cohorts. Significant DIF was identified for sex and educational level for a small number of items. PAM-13 scores were moderately correlated with depressive symptoms on the Depression Anxiety Stress Scale and Assessment of Quality of Life-6D. There were small correlations between PAM-13 and Knee injury and Osteoarthritis Outcome Score pain and activities of daily living scores.

CONCLUSIONS

This study provides some evidence of adequate person and item reliability, unidimensionality, and construct validity to support the use of PAM-13 to measure patient activation in people living with hip and knee OA. Possible limitations regarding targeting, different item difficulty order, DIF and local response dependence should be investigated in future research.

The effect of weight loss on the progression of meniscal extrusion and size in knee osteoarthritis: a post-hoc analysis of the Intensive Diet and Exercise for Arthritis (IDEA) trial

OBJECTIVE

Weight loss has beneficial effects on clinical outcomes in knee osteoarthritis (OA), but the mechanism is still unclear. Since meniscus extrusion is associated with knee pain, this study assessed whether weight loss by diet and/or exercise is associated with less progression in meniscus extrusion measures over time.

DESIGN

The Intensive Diet and Exercise for Arthritis trial (IDEA) was a prospective, single-blind, randomized-controlled trial including overweight and obese older adults with knee pain and radiographic OA. Participants were randomized to 18-month interventions: exercise only, diet only or diet + exercise. In a random subsample of 105 participants, MRIs were obtained at baseline and follow-up. The medial and lateral menisci were segmented and quantitative position and size measures were obtained, along with semiquantitative extrusion measures. Linear and log-binomial regression were used to examine the association between change in weight and change in meniscus measures. Between-group differences were analyzed using an analysis of covariance.

RESULTS

Weight loss was associated with less progression over time of medial meniscus extrusion as measured by the maximum (β: -24.59 μm, 95%CI: -41.86, -7.33) and mean (β: -19.08 μm, 95%CI: -36.47, -1.70) extrusion distances. No relationships with weight loss were observed for lateral meniscus position, medial or lateral meniscus size or semiquantitative measures. Change in meniscus position and size did not differ significantly between groups.

CONCLUSIONS

Weight loss was associated with beneficial modifications of medial meniscus extrusion over 18 months. This may be one of the mechanisms by which weight loss translates into a clinical benefit.

CLINICAL TRIAL REGISTRATION

NCT00381290.

Qualitative and quantitative measures of prefemoral and quadriceps fat pads are associated with incident radiographic osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

To determine if qualitative and quantitative measures of prefemoral fat pad (PFP) and quadriceps fat pad (QFP) are associated with incident radiographic osteoarthritis (iROA) over 4 years in the Osteoarthritis Initiative (OAI) study.

DESIGN

Participants in this nested case-control study were selected from the OAI study with knees that had Kellgren Lawrence grades (KLG) of 0 or 1 at baseline. Case knees were defined by iROA (KLG≥ 2) over 4 years. Control knees without iROA were matched 1:1 with case knees. Magnetic resonance images (MRIs) were read at P0 (time of onset of iROA), P-1 (1 year prior to P0) and baseline, and used to assess PFP (i.e., prefemoral hyperintensity alteration, patellofemoral hyperintensity alteration, maximum axial area) and QFP (i.e., hyperintensity alteration, mass effect, maximum axial area). Conditional logistic regression analyses were performed to study the associations between PFP/QFP measures and iROA, after adjustment for covariates.

RESULTS

354 case knees with iROA were matched to 354 control knees. 66.9% of the participants were female, with an average age of 60.1 years. PFP prefemoral hyperintensity alteration measured at three time points (OR [95%CI]: 1.46 [1.18-1.82], 1.50 [1.20-1.88], 1.52 [1.22-1.89] respectively), PFP maximum axial area (OR [95%CI]: 1.07 [1.01-1.14], 1.08 [1.01-1.15], 1.08 [1.02-1.15] respectively) and QFP hyperintensity alteration (OR [95%CI]: 1.59 [1.27-2.00], 1.44 [1.13-1.82], 1.38 [1.09-1.73] respectively) were significantly associated with iROA in multivariable conditional logistic analyses. QFP mass effect measured at BL and P-1 (OR [95%CI]: 1.42 [1.11-1.82], 1.33 [1.01-1.73] respectively) were significantly associated with iROA.

CONCLUSIONS

Qualitative and quantitative measures of PFP and QFP are associated with increased iROA over 4 years.

The morphology of proximal tibiofibular joint (PTFJ) predicts incident radiographic osteoarthritis: data from Osteoarthritis Initiative

OBJECTIVE

To determine whether the morphology of proximal tibiofibular joint (PTFJ) is associated with increased risk of incident radiographic osteoarthritis (iROA) over 4 years in the OA Initiative (OAI) study.

METHODS

A nested matched case-control study design was used to select participants from OAI study. Case knees were defined as those with iROA. Control knees were matched one-to-one by sex, age and radiographic status with case knees. T2-weighted MR images were assessed at P0 (the visit when incident ROA was found on radiograph), P1 (1 year prior to P0) and at OAI baseline. The contacting area of PTFJ (S) and its projection areas onto the horizontal (load-bearing area, Sτ), sagittal (lateral stress-bolstering area, Sφ) and coronal plane (posterior stress-bolstering area, Sυ) were assessed, respectively.

RESULTS

354 case knees and 354 matched control knees were included, with a mean age of 60 and a mean body mass index (BMI) of 28 kg/m². Baseline PTFJ morphological parameters (S, Sτ and Sυ) were significantly associated with iROA over 4 years, and these associations remained unchanged after adjustment for BMI, number of knee bending activities, self-reported knee injury and surgery. S, Sτ and Sυ were also significantly associated with iROA at P1 and P0. In subgroup analysed, S, Sτ and Sυ were associated with risks of incident joint space narrowing in the medial, but not the lateral tibiofemoral compartment.

CONCLUSION

Greater contacting area, load-bearing area and posterior stress-bolstering area of PTFJ were associated with increased risks of iROA, largely in the medial tibiofemoral compartment.

Shifting the Gravity of Spending: Assessing the impact of PHE’s Prioritisation Framework

Background

Findings are presented from the evaluation of Public Health England’s (PHE) new Prioritisation Framework (PF) conducted between September 2017 and December 2018 aimed to help local authority commissioners with their public health investment and disinvestment decisions. The study explored the take up of the PF in three early adopter local authority settings.

Methods

Data collection was based on semi-structured interviews (n = 30) across three local authorities supplemented by participant observation of workshops and data concerning the implementation process as well as spend and outcomes both before and, where possible, after using the PF.

Results

Participants acknowledged that the PF provided a systematic way to guide prioritisation decisions and one that encouraged transparency over investment and disinvestment decisions. The role performed by PHE and its regional teams in facilitating the process was especially welcomed and considered to be critical to the adoption process. However, uptake of the PF required a significant investment of time and commitment from public health teams at a time when resources were stretched. The impact of the political environment in local government was a major factor determining the likely uptake of the PF. Ensuring committed leadership and engagement from senior politicians and officers was regarded as critical to success.

Conclusions

The study assessed the value of the PF and the processes surrounding its implementation and use. Further research could further explore the value of the tool in aiding investment and disinvestment decisions and its impact on spending.

Key messages

The PF provides a platform for engaged and informed deliberation about priorities and does so in an open, structured and transparent manner. Organisational and political context in which prioritisation occur shape the adoption of the PF tool.

Effect of cane use on bone marrow lesion volume in people with medial tibiofemoral knee osteoarthritis: randomized clinical trial

OBJECTIVE

To evaluate effects of daily cane use for 3 months on medial tibiofemoral bone marrow lesion (BML) volumes in people with medial tibiofemoral osteoarthritis (OA).

DESIGN

In this randomized controlled trial (RCT), 79 participants with medial tibiofemoral OA were randomized to either a cane group (using a cane whenever walking) or control group (not using any gait aid) for 3 months. The cane group received a single training session by a physiotherapist, using a biofeedback cane to teach optimal technique and body weight support and motor learning principles to facilitate retention of learning. The primary outcome was change in total medial tibiofemoral BML volume (per unit bone volume) measured from magnetic resonance imaging (MRI) at 3 months. Secondary outcomes were BML volumes (per unit bone volume) of the medial tibia and femur, and patient-reported outcomes of overall knee pain, knee pain on walking, physical function, perceived global symptom changes and health-related quality of life. MRI analyses were performed by a blinded assessor.

RESULTS

Seventy-eight participants (99%) completed the primary outcome. Mean (standard deviation) daily cane use was 2.3 (1.7) hours over 3 months. No evidence of between-group differences was found for change in total medial tibiofemoral BML volume (mean difference: -0.0010 (95% confidence intervals: -0.0022, 0.0003)). Most secondary outcomes showed minimal differences between groups.

CONCLUSION

Daily use of a cane during walking for 3 months aiming to reduce knee joint loading did not change medial tibiofemoral BML volumes compared to no use of gait aids.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry (ACTRN12614000909628).

Intra-articular corticosteroids and the risk of knee osteoarthritis progression: results from the Osteoarthritis Initiative

OBJECTIVE

A recent randomized clinical trial reported that repeated intra-articular corticosteroids (IACs) were associated with a greater cartilage loss. This study aimed to examine the relation of IACs to knee radiographic osteoarthritis (ROA) progression in a real-world setting.

DESIGN

A cohort that initiated IACs and a comparison cohort without IACs from participants with mild to moderate knee ROA in the Osteoarthritis Initiative (OAI) were assembled (from 0-month to 48-month). Two measures of knee ROA progression were assessed during the follow-up period: (1) an increase in Kellgren and Lawrence (KL) grade by ≥1 grade or having a knee replacement (i.e., KL grade worsening); and (2) a decrease in joint space width (JSW) by ≥0.7 mm or having a knee replacement (i.e., JSW worsening). The associations of IACs initiation using a propensity-score matched cohort study and continuous IACs using marginal structural models with the risk of knee ROA progression were examined.

RESULTS

Among 684 propensity-score matched participants at baseline (148 IACs initiators, 536 comparators), 65 knees (21.7/100 person-years) in the IACs initiation cohort and 90 knees (7.1/100 person-years) in the comparison cohort experienced KL worsening. The hazard ratios (HRs) of KL worsening from IACs initiation and continuous IACs were 3.02 (95% confidence interval [CI], 2.19-4.16) and 4.67 (95% CI, 2.92-7.47), respectively. The corresponding HRs of JSW worsening were 2.93 (95% CI, 2.13-4.02) and 3.26 (95% CI, 1.78-5.96), respectively. All HRs for continuous use of IACs were further away from the null.

CONCLUSIONS

IACs, especially continuous IACs, may be associated with an increased risk of knee ROA progression.

Trajectories of femorotibial cartilage thickness among persons with or at risk of knee osteoarthritis: development of a prediction model to identify progressors

OBJECTIVE

There is significant variability in the trajectory of structural progression across people with knee osteoarthritis (OA). We aimed to identify distinct trajectories of femorotibial cartilage thickness over 2 years and develop a prediction model to identify individuals experiencing progressive cartilage loss.

METHODS

We analysed data from the Osteoarthritis Initiative (OAI) (n = 1,014). Latent class growth analysis (LCGA) was used to identify trajectories of medial femorotibial cartilage thickness assessed on magnetic resonance imaging (MRI) at baseline, 1 and 2 years. Baseline characteristics were compared between trajectory-based subgroups and a prediction model was developed including those with frequent knee symptoms at baseline (n = 686). To examine clinical relevance of the trajectories, we assessed their association with concurrent changes in knee pain and incidence of total knee replacement (TKR) over 4 years.

RESULTS

The optimal model identified three distinct trajectories: (1) stable (87.7% of the population, mean change -0.08 mm, SD 0.19); (2) moderate cartilage loss (10.0%, -0.75 mm, SD 0.16) and (3) substantial cartilage loss (2.2%, -1.38 mm, SD 0.23). Higher Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) pain scores, family history of TKR, obesity, radiographic medial joint space narrowing (JSN) ≥1 and pain duration ≤1 year were predictive of belonging to either the moderate or substantial cartilage loss trajectory [area under the curve (AUC) 0.79, 95% confidence interval (CI) 0.74, 0.84]. The two progression trajectories combined were associated with pain progression (OR 1.99, 95% CI 1.34, 2.97) and incidence of TKR (OR 4.34, 1.62, 11.62).

CONCLUSIONS

A minority of individuals follow a progressive cartilage loss trajectory which was strongly associated with poorer clinical outcomes. If externally validated, the prediction model may help to select individuals who may benefit from cartilage-targeted therapies.

Diagnostic performance of knee physical exam and participant-reported symptoms for MRI-detected effusion-synovitis among participants with early or late stage knee osteoarthritis: data from the Osteoarthritis Initiative

OBJECTIVE

Evaluate the diagnostic performance of knee physical exam findings and participant-reported symptoms for MRI-detected effusion-synovitis (ES) among knees with early and late-stage osteoarthritis (OA).

DESIGN

The Osteoarthritis Initiative (OAI) is a longitudinal study of participants with or at risk for knee OA. Two samples with MRI readings were available: 344 knees with early OA (312 participants) and 216 with late-stage OA (186 participants). Trained examiners performed bulge sign (BS) and patellar tap (PT) exams, and participants reported on knee swelling and pain with leg straightening. Effusion-synovitis on 3T non-contrast MRI was scored using the MRI Osteoarthritis Knee Score (MOAKS). Diagnostic performance of physical exam findings and symptoms was estimated with bootstrapped confidence intervals.

RESULTS

For the early OA sample, the highest sensitivity for medium/large effusion-synovitis was achieved with a positive finding for any of the physical exam maneuvers and/or participant-reported symptoms (81.0 [95% CI: 70.0, 91.3]). Both knee symptoms in combination had a prevalence of 11.7% and yielded the highest estimated positive predictive value (PPV) (50.0 [95% CI: 34.2, 66.7]) and likelihood ratio positive (LR+) (5.2 [95% CI: 2.9, 9.7]). In late-stage OA knees, exam findings and symptoms provided minimal information beyond the prevalence.

CONCLUSION

Patient report of both symptoms, or at least one positive exam finding and at least one symptom, could be used to identify knees at increased risk of effusion-synovitis in knees with early stage OA, either for screening purposes in clinical evaluation, or for study sample enrichment with an inflammatory phenotype; diagnostic performance was not sufficiently high for clinical diagnostic purposes.

Poor replicability of recommended exercise interventions for knee osteoarthritis: a descriptive analysis of evidence informing current guidelines and recommendations

OBJECTIVE

To examine the reporting completeness of exercise-based interventions for knee osteoarthritis (OA) in studies that form the basis of current clinical guidelines, and examine if the clinical benefit (pain and disability) from exercise is associated with the intervention reporting completeness.

DESIGN

Review of clinical OA guidelines METHODS: We searched MEDLINE and EMBASE for guidelines published between 2006 and 2016 including recommendations about exercise for knee OA. The studies used to inform a recommendation were reviewed for exercise reporting completeness. Reporting completeness was evaluated using a 12-item checklist; a combination of the Template for Intervention Description and Replication (TIDieR) and Consensus on Exercise Reporting Template (CERT). Each item was scored 'YES' or 'NO' and summarized as a proportion of interventions with complete descriptions and each intervention's completeness was summarized as the percentage of completely described items. The association between intervention description completeness score and clinical benefits was analyzed with a multilevel meta-regression.

RESULTS

From 10 clinical guidelines, we identified 103 original studies of which 100 were retrievable (including 133 interventions with 6,926 patients). No interventions were completely described on all 12 items (median 33% of items complete; range 17-75%). The meta-regression analysis indicated that poorer reporting was associated with greater effects on pain and no association with effects on disability.

CONCLUSION

The inadequate description of recommended interventions for knee OA is a serious problem that precludes replication of effective interventions in clinical practice. By consequence, the relevance and usability of clinical guideline documents and original study reports are diminished.

PROSPERO

CRD42016039742.

Correction to: Effectiveness of a new model of primary care management on knee pain and function in patients with knee osteoarthritis: Protocol for THE PARTNER STUDY

After the publication of this protocol [1], our collaborator Prima Health solutions advised us of their intent to withdraw from the study.

Mitochondrial DNA haplogroups associated with MRI-detected structural damage in early knee osteoarthritis

OBJECTIVE

Magnetic resonance imaging (MRI)-detected structural features are associated with increased risk of radiographic osteoarthritis (ROA). Specific mitochondrial DNA (mtDNA) haplogroups have been associated with incident ROA. Our objective was to compare the presence of MRI-detected structural features across mtDNA haplogroups among knees that developed incident ROA.

DESIGN

Knees from the Osteoarthritis Initiative (OAI) that developed incident ROA during 48 months follow-up were identified from Caucasian participants. mtDNA haplogroups were assigned based on a single base extension assay. MRIs were obtained annually between baseline and 4-year follow-up and scored using the MRI Osteoarthritis Knee Score (MOAKS). The association between mtDNA haplogroups and MRI-detected structural features was estimated using log-binomial regression. Participants who carried haplogroup H served as the reference group.

RESULTS

The sample included 255 participants contributing 277 knees that developed ROA. Haplogroups included H (116, 45%), J (17, 7%), T (26, 10%), Uk (61, 24%), and the remaining less common haplogroups ("others") (35, 14%). Knees of participants with haplogroup J had significantly lower risk of medium/large bone marrow lesions (BMLs) in the medial compartment [3.2%, relative risks (RR) = 0.17; 95%CI: 0.05, 0.64; P = 0.009] compared to knees of participants who carried haplogroup H [16.3%], as did knees from participants within the "others" group [2.8%, RR = 0.20; 95%CI: 0.08, 0.55; P = 0.002], over the 4 year follow-up period.

CONCLUSIONS

mtDNA haplogroup J was associated with lower risk of BMLs in the medial compartment among knees that developed ROA. Our results offer a potential hypothesis to explain the mechanism underlying the previously reported protective association between haplogroup J and ROA.

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Capacity for evidence-informed policymaking across Europe: development and piloting of a multistakeholder survey

OBJECTIVES

Evidence-informed policymaking (EIP) is increasingly viewed as a complex endeavour that requires integration of research evidence with available resources and the preferences of those affected by the policy. The first technical expert meeting to enhance EIP in the World Health Organization (WHO) European Region identified the scope to develop and conduct a survey to gather insights into the generation, translation and application of research evidence across the region. This article describes the process of developing and piloting a multistakeholder survey (promoted and technically supported by WHO/Europe) on the topic of capacity for EIP.

STUDY DESIGN

Rapid review and pilot cross-sectional survey.

METHODS

A survey instrument was developed based on findings from the published literature and refined with input from EIP experts/champions. The online survey was then piloted using various recruitment strategies designed to maximise its reach among the key target groups (senior researchers, knowledge brokers and members of civil society).

RESULTS

The rapid review revealed a clear gap in the evidence base in relation to broader surveys of capacity for EIP, as opposed to evidence-based practice at an individual level. Thirteen responses to the pilot survey were received from individuals in 10 European countries. Reported barriers to EIP included a lack of understanding among policymakers and a lack of interaction with researchers. There were examples of efforts to enhance capacity for EIP, both at region or country level and through membership of international networks and collaborations. However, few examples were given of the application and impact of research evidence on the policymaking process.

CONCLUSION

This research has demonstrated the feasibility of developing and piloting a multicountry, multistakeholder survey to generate better understanding of evidence use in health policymaking. Next steps include incorporating the lessons learned into a revised version of the survey to be implemented with all 53 WHO/Europe Member States.

Clinimetrics of ultrasound pathologies in osteoarthritis: systematic literature review and meta-analysis

OBJECTIVE

The aims of this study were to systematically review clinimetrics of commonly assessed ultrasound pathologies in knee, hip and hand osteoarthritis (OA), and to conduct a meta-analysis for each clinimetric.

METHODS

Medline, Embase, and Cochrane Library databases were searched from their inceptions to September 2016. According to the Outcome Measures in Rheumatology (OMERACT) Instrument Selection Algorithm, data extraction focused on ultrasound technical features and performance metrics. Methodological quality was assessed with modified 19-item Downs and Black score and 11-item Quality Appraisal of Diagnostic Reliability (QAREL) score. Separate meta-analyses were performed for clinimetrics: (1) inter-rater/intra-rater reliability; (2) construct validity; (3) criteria validity; and (4) internal/external responsiveness. Statistical Package for the Social Sciences (SPSS), Excel and Comprehensive Meta-analysis were used.

RESULT

Our search identified 1126 records; of these, 100 were eligible, including a total of 8542 patients and 32,373 joints. The average Downs and Black score was 13.01, and average QAREL was 5.93. The stratified meta-analysis was performed only for knee OA, which demonstrated moderate to substantial reliability [minimum kappa > 0.44(0.15,0.74), minimum intraclass correlation coefficient (ICC) > 0.82(0.73-0.89)], weak construct validity against pain (r = 0.12 to 0.27), function (r = 0.15 to 0.23), and blood biomarkers (r = 0.01 to 0.21), but weak to strong correlation with plain radiography (r = 0.13 to 0.60), strong association with Magnetic Resonance Imaging (MRI) [minimum r = 0.60(0.52,0.67)] and strong discrimination against symptomatic patients (OR = 3.08 to 7.46). There was strong criterion validity against cartilage histology [r = 0.66(-0.05,0.93)], and small to moderate internal [standardized mean difference(SMD) = 0.20 to 0.58] and external (r = 0.35 to 0.43) responsiveness to interventions.

CONCLUSION

Ultrasound demonstrated strong criterion validity with cartilage histology, poor to strong correlation with patient findings and MRI, moderate reliability, and low responsiveness to interventions.

PROSPERO REGISTRATION NO

CRD42016039954.

The importance of synovial inflammation in osteoarthritis: current evidence from imaging assessments and clinical trials

Synovial abnormalities have been observed at multiple stages of osteoarthritis (OA). Increasing evidence suggests that it may play an important role in the OA pathological process. Many assessment systems using magnetic resonance imaging (MRI) and ultrasound have been established to detect synovial inflammation in OA. These have been used to inform the current investigation of OA disease phenotypes and progression and can be utilised in the future for clinical trials developing potential treatments. This narrative review aims to illustrate the importance of synovial tissue in OA and provide an overview of imaging assessments and possible therapies targeting synovial abnormalities.

Moderators and mediators of effects of unloading shoes on knee pain in people with knee osteoarthritis: an exploratory analysis of the SHARK randomised controlled trial

OBJECTIVE

To investigate moderators and biomechanical mediators of effects of unloading shoes on knee pain in people with knee osteoarthritis (OA).

METHODS

Exploratory analysis from 164 participants in a clinical trial comparing unloading (ASICS GEL-Melbourne OA) to conventional walking shoes. The primary outcome was 6-month change in knee pain (11-point numerical rating scale (NRS)). Moderators included baseline peak knee adduction moment (KAM), radiographic severity (Kellgren & Lawrence (KL) scale), body mass, foot posture, neuropathic pain and diffuse knee pain. Mediators included change in peak KAM and KAM impulse.

RESULTS

Radiographic severity was the only moderator to interact with footwear group (P = 0.02). Participants with KL = 2 experienced greater pain reductions with conventional compared to unloading shoes (mean difference in change in pain -1.64 units, 95% CI -3.07, -0.21), while unloading shoes tended to result in greater pain reductions than conventional shoes in KL = 3 (0.98, 95% CI -0.44, 2.39) and KL = 4 (0.64, 95% CI -0.64, 1.93). No variable showed any significant mediating effect in the entire cohort. However, there was some evidence that unloading shoes may reduce pain through reductions in peak KAM (indirect effect -0.31, 95% CIs -0.65, 0.03; P = 0.07) in people with KL ≥ 3, compared to conventional shoes.

CONCLUSION

Unloading shoes conferred additional symptomatic benefits over conventional shoes in people with moderate to severe knee OA. There was some evidence effects may be mediated by a reduction in peak KAM. However, we were underpowered for subgroup analyses. These patients may represent a subgroup to which biomechanical interventions designed to reduce the KAM may be more effectively targeted.

Predictive and concurrent validity of cartilage thickness change as a marker of knee osteoarthritis progression: data from the Osteoarthritis Initiative

OBJECTIVE

To investigate the predictive and concurrent validity of magnetic resonance imaging (MRI)-based cartilage thickness change between baseline (BL) and year-two (Y2) follow-up (predictive validity) and between Y2 and Y4 follow-up (concurrent validity) for symptomatic and radiographic knee osteoarthritis (OA) progression during Y2→Y4.

METHODS

777 knees from 777 Osteoarthritis Initiative (OAI) participants (age: 61.3 ± 9.0 years, BMI: 30.1 ± 4.8 kg/m²) with Kellgren Lawrence (KL) grade 1-3 at Y2 (visit before progression interval) had cartilage thickness measurements from 3T MRI at BL, Y2 (n = 777), and Y4 (n = 708). Analysis of covariance and logistic regression were used to assess the association of pain progression (≥9 WOMAC units [scale 0-100], n = 205/572 with/without progression) and radiographic progression (≥0.7 mm minimum joint space width (mJSW) loss, n = 166/611 with/without progression) between Y2 and Y4 with preceding (BL→Y2) and concurrent (Y2→Y4) change in central medial femorotibial (cMFTC) compartment cartilage thickness.

RESULTS

Symptomatic progression was associated with concurrent (Y2→Y4: -305 ± 470 μm vs -155 ± 346 μm, Odds ratios (OR) = 1.5 [1.2, 1.7]) but not with preceding cartilage thickness loss in cMFTC (-150 ± 276 μm vs -151 ± 299 μm, OR = 0.9 95% CI: [0.8, 1.1]). Radiographic progression, in contrast, was significantly associated with both concurrent (-542 ± 550 μm vs -98 ± 255 μm, OR = 3.4 [2.6, 4.3]) and preceding cMFTC thickness loss (-229 ± 355 μm vs -130 ± 270 μm, OR = 1.3 [1.1, 1.5]).

CONCLUSIONS

These results extend previous reports that did not discern predictive vs concurrent associations of cartilage thickness loss with OA progression. The observed predictive and concurrent validity of cartilage thickness loss for radiographic progression and observed concurrent validity for symptomatic progression provide an important step in qualifying cartilage thickness loss as a biomarker of knee OA progression. CLINICALTRIALS.

GOV IDENTIFICATION

NCT00080171.

Is synovitis detected on non-contrast-enhanced magnetic resonance imaging associated with serum biomarkers and clinical signs of effusion? Data from the Osteoarthritis Initiative

OBJECTIVES

To determine the relationship between synovitis detected on non-contrast-enhanced (non-CE) magnetic resonance imaging (MRI), biochemical markers of inflammation, and clinical assessment of effusion in people with knee osteoarthritis (OA).

METHOD

We examined data from the OA Biomarkers Consortium within the Osteoarthritis Initiative (n = 600). Non-CE MRIs were semi-quantitatively scored (grades 0-3) for severity of Hoffa synovitis and effusion synovitis. Serum (s) matrix metalloproteinase-3 (sMMP-3), hyaluronic acid (sHA), and nitrated epitope of the α-helical region of type II collagen (sColl2-1NO2) were quantified. The bulge and patellar tap clinical tests were performed at baseline and performance characteristics were assessed for the detection of effusion synovitis on MRI. Multinomial logistic regression adjusted for covariates was used to assess the association between biochemical and imaging markers at baseline and over 12 and 24 months.

RESULTS

At baseline, sHA and sMMP-3 were associated with moderate to large (score ≥ 2, n = 117) effusion synovitis, with odds ratio = 1.35 and 1.30 per 1 standard deviation in biochemical markers (95% confidence intervals 1.07, 1.71 and 1.00, 1.69), c-statistics 0.640 and 0.626, respectively. The c-statistics for the presence of Hoffa synovitis (score ≥ 2) were 0.693, 0.694, and 0.694 for sHA, sMMP-3, and sColl2-1NO2, respectively. There was no significant association between biochemical markers (baseline and 12 and 24 month time-integrated concentrations) and changes in MRI markers. The bulge and patellar tap signs were 22.0% and 4.3% sensitive and 88.8% and 94.8% specific, respectively, for detecting effusion synovitis (score ≥ 1) on MRI.

CONCLUSIONS

sHA and sMMP-3 were modestly associated with effusion synovitis at baseline. Clinical signs of effusion are insensitive but highly specific for the presence of any effusion synovitis on non-CE MRI.

Instruments assessing attitudes toward or capability regarding self-management of osteoarthritis: a systematic review of measurement properties

OBJECTIVE

To make a recommendation on the "best" instrument to assess attitudes toward and/or capabilities regarding self-management of osteoarthritis (OA) based on available measurement property evidence.

METHODS

Electronic searches were performed in MEDLINE, EMBASE, CINAHL and PsychINFO (inception to 27 December 2016). Two reviewers independently rated measurement properties using the Consensus-based Standards for the selection of Health Measurement Instruments (COSMIN) 4-point scale. Best evidence synthesis was determined by considering COSMIN ratings for measurement property results and the level of evidence available for each measurement property of each instrument.

RESULTS

Eight studies out of 5653 publications met the inclusion criteria, with eight instruments identified for evaluation: Multidimensional Health Locus of Control (MHLC), Perceived Behavioural Control (PBC), Patient Activation Measure (PAM), Educational Needs Assessment (ENAT), Stages of Change Questionnaire in Osteoarthritis (SCQOA), Effective Consumer Scale (EC-17) and Perceived Efficacy in Patient-Physician Interactions five item (PEPPI-5) and ten item scales. Measurement properties assessed for these instruments included internal consistency (k = 8), structural validity (k = 8), test-retest reliability (k = 2), measurement error (k = 1), hypothesis testing (k = 3) and cross-cultural validity (k = 3). No information was available for content validity, responsiveness or minimal important change (MIC)/minimal important difference (MID). The Dutch PEPPI-5 demonstrated the best measurement property evidence; strong evidence for internal consistency and structural validity but limited evidence for reliability and construct validity.

CONCLUSION

Although PEPPI-5 was identified as having the best measurement properties, overall there is a poor level of evidence currently available concerning measurement properties of instruments to assess attitudes toward and/or capabilities regarding osteoarthritis self-management. Further well-designed studies investigating measurement properties of existing instruments are required.

The relationship between foot and ankle symptoms and risk of developing knee osteoarthritis: data from the osteoarthritis initiative

OBJECTIVE

To investigate whether foot and/or ankle symptoms increase the risk of developing (1) knee symptoms and (2) symptomatic radiographic knee osteoarthritis (OA).

DESIGN

1020 Osteoarthritis Initiative (OAI) participants who were at-risk of knee OA, but were without knee symptoms or radiographic knee OA, were investigated. Participants indicated the presence and laterality of foot/ankle symptoms at baseline. The main outcome was development of knee symptoms (pain, aching or stiffness in and around the knee on most days of the month for at least 1 month in the past year). A secondary outcome was development of symptomatic radiographic knee OA (symptoms plus Kellgren and Lawrence [KL] grade ≥2), over the subsequent 4 years. Associations between foot/ankle symptoms and study outcomes were assessed by logistic regression models.

RESULTS

Foot/ankle symptoms in either or both feet significantly increased the odds of developing knee symptoms (adjusted odds ratio (OR) 1.55, 95% confidence interval (CI) 1.10 to 2.19), and developing symptomatic radiographic knee OA (adjusted OR 3.28, 95% CI 1.69 to 6.37). Based on laterality, contralateral foot/ankle symptoms were associated with developing both knee symptoms (adjusted OR 1.68, 95% CI 1.05 to 2.68) and symptomatic radiographic knee OA (adjusted OR 3.08, 95% CI 1.06 to 8.98), whilst bilateral foot/ankle symptoms were associated with developing symptomatic radiographic knee OA (adjusted OR 4.02, 95% CI 1.76 to 9.17).

CONCLUSION

In individuals at-risk of knee OA, the presence of contralateral foot/ankle symptoms in particular increases risk of developing both knee symptoms and symptomatic radiographic knee OA.

The knee adduction moment and knee osteoarthritis symptoms: relationships according to radiographic disease severity

OBJECTIVE

To investigate relationships between external knee adduction moment parameters (KAM) and osteoarthritis (OA) symptoms according to disease severity.

DESIGN

164 participants with symptomatic medial knee OA were included. Radiographic severity was graded by (1) Kellgren & Lawrence (KL) scale (Grade 2, n = 49; Grade, n = 52; Grade 4, n = 63) and; (2) medial tibiofemoral joint space narrowing (JSN) (Grade 1, n = 47; Grade 2, n = 50; Grade 3, n = 67). KAM-related parameters (peak KAM, KAM impulse and cumulative load) were determined from three-dimensional gait analysis and pedometry. Cumulative load was determined by multiplying KAM impulse by the average number of steps/day recorded over at least 5 days. Symptoms were assessed via numeric rating scale ((NRS), pain) and Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index (pain and physical function). Relationships between KAM parameters (independent variables) and symptoms (dependent variables) were evaluated by radiographic severity using linear models, adjusting for covariates.

RESULTS

In mild disease (either KL Grade 2 or JSN Grade 1), there were no associations between KAM and symptoms. In moderate disease of KL Grade 3, higher KAM impulse was associated with greater WOMAC pain. In severe disease (KL Grade 4), higher KAM impulse was associated with less WOMAC pain (KL Grade 4), while higher peak KAM was associated with better function (KL Grade 4). Higher cumulative knee adduction load was associated with less pain on both NRS and WOMAC (JSN Grade 3) as well as better function (both JSN Grade 3 and KL Grade 4).

CONCLUSIONS

Relationships between KAM-related parameters and symptoms differ according to underlying radiographic OA severity.

The influence of weather on the risk of pain exacerbation in patients with knee osteoarthritis - a case-crossover study

OBJECTIVE

To quantify the risk of knee pain exacerbation associated with temperature, relative humidity, air pressure and precipitation in persons with knee osteoarthritis.

METHOD

A web-based case-crossover study was conducted. Participants with a diagnosis of symptomatic, radiographic knee osteoarthritis were measured at baseline and followed for 3 months. Participants were instructed to log on to the study website if they perceived experiencing knee pain exacerbation (hazard period). Pain exacerbation was defined as an increase of ≥2 on a 0-10 numeric rating scale (NRS) from the participant's mildest pain reported at baseline. A time-stratified case-crossover study was conducted to anchor the corresponding hazard date to four control periods within a particular 35-day interval. Data on maximum and minimum temperature (°C), relative humidity (%), barometric pressure (hPa) and precipitation (mm) were obtained for the hazard and control periods from the publicly available meteorological database of the Australian Bureau of Meteorology. The associations were assessed using conditional logistic regression.

RESULTS

Of the 345 participants recruited, 171 participants (women: 64%, mean age: 62 years, mean BMI: 30.2 kg/m²) experienced at least one episode of pain exacerbation, yielding 1,425 observations included in the analyses. There was no apparent association between temperature, relative humidity, air pressure or precipitation and risk of knee pain exacerbation.

CONCLUSION

Despite anecdotal reports from patients, change in weather factors does not appear to influence the risk of pain exacerbation in persons with knee osteoarthritis. Additional studies should quantify the association of weather and risk of pain exacerbation in regions with more extreme weather conditions.

Axin2-expressing cells execute regeneration after skeletal injury

The mammalian skeleton performs a diverse range of vital functions, requiring mechanisms of regeneration that restore functional skeletal cell populations after injury. We hypothesized that the Wnt pathway specifies distinct functional subsets of skeletal cell types, and that lineage tracing of Wnt-responding cells (WRCs) using the Axin2 gene in mice identifies a population of long-lived skeletal cells on the periosteum of long bone. Ablation of these WRCs disrupts healing after injury, and three-dimensional finite element modeling of the regenerate delineates their essential role in functional bone regeneration. These progenitor cells in the periosteum are activated upon injury and give rise to both cartilage and bone. Indeed, our findings suggest that WRCs may serve as a therapeutic target in the setting of impaired skeletal regeneration.

A novel method for assessing signal intensity within infrapatellar fat pad on MR images in patients with knee osteoarthritis

PURPOSE

To assess reliability and validity of a semi-automated quantitative method to measure infrapatellar fat pad (IPFP) signal intensity in patients with knee osteoarthritis (OA).

METHODS

Hundred patients with knee OA were selected. Sagittal planes of fat-saturated T2-weighted images obtained on 1.5-T magnetic resonance imaging (MRI) were utilized to assess IPFP signal intensity using MATLAB. Knee structural abnormalities including cartilage defects, bone marrow lesions (BML) and radiographic OA (ROA) were evaluated. Clinical construct validity and concurrent validity were examined through describing associations of IPFP measurements with knee structural abnormalities and a semi-quantitative scoring method, respectively. The reliability was examined by calculating the intra- and inter-observer correlation coefficients.

RESULTS

Significantly positive associations were found between standard deviation of IPFP signal intensity [sDev (IPFP)], clustering factor (H) and all knee structural abnormalities. The volume of high signal intensity regions [Volume (H)] and the ratio of Volume (H) to volume of whole IPFP [Percentage (H)] were positively associated with cartilage defects and ROA, but not with BMLs. The median value [Median (H)] and upper quartile value [UQ (H)] of high signal intensity were only significantly associated with quartiles of cartilage defect score. Significant correlations were found between all quantitative measurements and semi-quantitative scores (All P < 0.001). Intraclass and interclass correlation coefficients for these quantitative measures were high (>0.90).

CONCLUSIONS

A novel and efficient method to segment IPFP and calculate its signal intensity on T2-weighted MRI images is documented. This method is reproducible, and has concurrent and clinical construct validity, but its predictive validity needs to be examined by future longitudinal studies.

Clinical algorithms to aid osteoarthritis guideline dissemination

BACKGROUND

Numerous scientific organisations have developed evidence-based recommendations aiming to optimise the management of osteoarthritis (OA). Uptake, however, has been suboptimal. The purpose of this exercise was to harmonize the recent recommendations and develop a user-friendly treatment algorithm to facilitate translation of evidence into practice.

METHODS

We updated a previous systematic review on clinical practice guidelines (CPGs) for OA management. The guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation for quality and the standards for developing trustworthy CPGs as established by the National Academy of Medicine (NAM). Four case scenarios and algorithms were developed by consensus of a multidisciplinary panel.

RESULTS

Sixteen guidelines were included in the systematic review. Most recommendations were directed toward physicians and allied health professionals, and most had multi-disciplinary input. Analysis for trustworthiness suggests that many guidelines still present a lack of transparency. A treatment algorithm was developed for each case scenario advised by recommendations from guidelines and based on panel consensus.

CONCLUSION

Strategies to facilitate the implementation of guidelines in clinical practice are necessary. The algorithms proposed are examples of how to apply recommendations in the clinical context, helping the clinician to visualise the patient flow and timing of different treatment modalities.

Location of knee pain in medial knee osteoarthritis: patterns and associations with self-reported clinical symptoms

OBJECTIVES

To (1) document pain location in medial tibiofemoral osteoarthritis (OA) using the patient-administered Photographic Knee Pain Map (PKPM); (2) compare pain severity, nature and likelihood of neuropathic-like symptoms, physical dysfunction and presence of symptoms at other sites across the most common pain patterns.

DESIGN

Baseline data were analysed from 164 participants with medial tibiofemoral OA (TFJOA) participating in a randomised controlled trial (RCT). Participants completed the PKPM indicating all relevant pain zones of their most painful knee. Pain zones were collapsed into regions to determine patterns of pain. Symptoms were quantified using numeric rating scales (NRSs) of pain severity, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Intermittent and Constant Osteoarthritis Pain (ICOAP) and painDETECT questionnaires. Symptoms at other joints were categorised as present/absent.

RESULTS

The medial joint line (n = 123, 75%), patellar tendon (n = 62, 38%) and posterior knee (n = 61, 37%) were the most frequently reported pain zones. The most frequent patterns were diffuse (41%), isolated medial (16%), anterior-medial (12%) and medial-posterior (11%) pain. WOMAC and ICOAP scores were higher in the diffuse compared to anterior-medial patterns. Mean PainDETECT scores were higher with both diffuse and medial-posterior pain relative to anterior-medial pain.

CONCLUSION

Only 16% of the cohort indicated isolated medial knee pain, whilst a diffuse pain pattern was most common. People with diffuse knee pain reported more severe pain and physical dysfunction than those with anterior-medial pain. Prevalence of possible/likely neuropathic-like symptoms tended to be more frequent in diffuse and posterior-medial patterns compared to anterior-medial pain.

Model-based evaluation of cost-effectiveness of nerve growth factor inhibitors in knee osteoarthritis: impact of drug cost, toxicity, and means of administration

OBJECTIVE

Studies suggest nerve growth factor inhibitors (NGFi) relieve pain but may accelerate disease progression in some patients with osteoarthritis (OA). We sought cost and toxicity thresholds that would make NGFi a cost-effective treatment for moderate-to-severe knee OA.

DESIGN

We used the Osteoarthritis Policy (OAPol) model to estimate the cost-effectiveness of NGFi compared to standard of care (SOC) in OA, using Tanezumab as an example. Efficacy and rates of accelerated OA progression were based on published studies. We varied the price/dose from $200 to $1000. We considered self-administered subcutaneous (SC) injections (no administration cost) vs provider-administered intravenous (IV) infusion ($69-$433/dose). Strategies were defined as cost-effective if their incremental cost-effectiveness ratio (ICER) was less than $100,000/quality-adjusted life year (QALY). In sensitivity analyses we varied efficacy, toxicity, and costs.

RESULTS

SOC in patients with high levels of pain led to an average discounted quality-adjusted life expectancy of 11.15 QALYs, a lifetime risk of total knee replacement surgery (TKR) of 74%, and cumulative discounted direct medical costs of $148,700. Adding Tanezumab increased QALYs to 11.42, reduced primary TKR utilization to 63%, and increased costs to between $155,400 and $199,500. In the base-case analysis, Tanezumab at $600/dose was cost-effective when delivered outside of a hospital. At $1000/dose, Tanezumab was not cost-effective in all but the most optimistic scenario. Only at rates of accelerated OA progression of 10% or more (10-fold higher than reported values) did Tanezumab decrease QALYs and fail to represent a viable option.

CONCLUSIONS

At $100,000/QALY, Tanezumab would be cost effective if priced ≤$400/dose in all settings except IV hospital delivery.

Brief Report: Cartilage Thickness Change as an Imaging Biomarker of Knee Osteoarthritis Progression: Data From the Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium

OBJECTIVE

To investigate the association of cartilage thickness change over 24 months, as determined by magnetic resonance imaging (MRI), with knee osteoarthritis (OA) progression at 24-48 months.

METHODS

This nested case-control study included 600 knees with a baseline Kellgren/Lawrence (K/L) grade of 1-3 from 600 Osteoarthritis Initiative (OAI) participants. Case knees (n = 194) had both medial tibiofemoral radiographic joint space loss (≥0.7 mm) and a persistent increase in the Western Ontario and McMaster Universities Osteoarthritis Index pain score (≥9 on a 0-100 scale) 24-48 months from baseline. Control knees (n = 406) included 200 with neither radiographic nor pain progression, 103 with radiographic progression only, and 103 with pain progression only. Medial and lateral femorotibial cartilage was segmented from sagittal 3T MRIs at baseline, 12 months, and 24 months. Logistic regression was used to assess the association of change in cartilage thickness, with a focus on the central medial femorotibial compartment, and OA progression.

RESULTS

Central medial femorotibial compartment thickness loss was significantly associated with case status, with an odds ratio (OR) of 1.9 (95% confidence interval [95% CI] 1.6-2.3) (P < 0.0001). Association with case status reached P < 0.05 for both the central femur (OR 1.8 [95% CI 1.5-2.2]) and the central tibia (OR 1.6 [95% CI 1.3-1.9]). Lateral femorotibial compartment cartilage thickness loss, in contrast, was not significantly associated with case status. A reduction in central medial femorotibial compartment cartilage thickness was strongly associated with radiographic progression (OR 4.0 [95% CI 2.9-5.3]; P < 0.0001) and only weakly associated with pain progression (OR 1.3 [95% CI 1.1-1.6]; P < 0.01).

CONCLUSION

Our findings indicate that loss of medial femorotibial cartilage thickness over 24 months is associated with the combination of radiographic and pain progression in the knee, with a stronger association for radiographic progression.