"You don't put it down to arthritis": A qualitative study of the first symptoms recalled by individuals with knee osteoarthritis

Objective

As part of the first phase of the OARSI Early-stage Symptomatic Knee Osteoarthritis (EsSKOA) initiative, we explored the first symptoms and experiences recalled by individuals with knee osteoarthritis (OA).

Design

This qualitative study, informed by qualitative description, was a secondary analysis of focus groups (n ​= ​17 groups) and one-on-one interviews (n ​= ​3) conducted in 91 individuals living with knee OA as part of an international study to better understand the OA pain experience. In each focus group or interview, participants were asked to describe their first symptoms of knee OA. We inductively coded these transcripts and conducted thematic analysis.

Results

Mean age of participants was 70 years (range 47-92) and 68 ​% were female. We developed four overarching themes: Insidious and Episodic Onset, Diverse Early Symptoms, Must be Something Else, and Adjustments. Participants described the gradual and intermittent way in which symptoms of knee OA developed over many years; many could not identify a specific starting point. Participants described diverse initial knee symptoms, including activity-exacerbated joint pain, stiffness and crepitus. Most participants dismissed early symptoms or rationalized their presence, employing various strategies to enable continued participation in recreational and daily activities. Few sought medical attention until physical functioning was demonstrably impacted.

Conclusions

The earliest symptoms of knee OA are frequently insidious in onset, episodic and present long before individuals present to health professionals. These results highlight challenges to identifying people with knee OA early and support the development of specific classification criteria for EsSKOA to capture individuals at an early stage.

3D analysis and grading of calcifications from ex vivo human meniscus

OBJECTIVE

Meniscal calcifications are associated with the pathogenesis of knee osteoarthritis (OA). We propose a micro-computed tomography (μCT) based 3D analysis of meniscal calcifications ex vivo, including a new grading system.

METHOD

Human medial and lateral menisci were obtained from 10 patients having total knee replacement for medial compartment OA and 10 deceased donors without knee OA (healthy references). The samples were fixed; one subsection was imaged with μCT, and the adjacent tissue was processed for histological evaluation. Calcifications were examined from the reconstructed 3D μCT images, and a new grading system was developed. To validate the grading system, meniscal calcification volumes (CV_M) were quantitatively analyzed and compared between the calcification grades. Furthermore, we estimated the relationship between histopathological degeneration and the calcification severity.

RESULTS

3D μCT images depict calcifications in every sample, including diminutive calcifications that are not visible in histology. In the new grading system, starting from grade 2, each grade results in a CV_M that is 20.3 times higher (95% CI 13.3-30.5) than in the previous grade. However, there was no apparent difference in CV_M between grades 1 and 2. The calcification grades appear to increase with the increasing histopathological degeneration, although histopathological degeneration is also observed with small calcification grades.

CONCLUSIONS

3D μCT grading of meniscal calcifications is feasible. Interestingly, it seems that there are two patterns of degeneration in the menisci of our sample set: 1) with diminutive calcifications (calcification grades 1-2), and 2) with large to widespread calcifications (calcification grades 3-5).

Occurrence of comorbidity following osteoarthritis diagnosis: a cohort study in the Netherlands

OBJECTIVE

To determine the risk of comorbidity following diagnosis of knee or hip osteoarthritis (OA).

DESIGN

A cohort study was conducted using the Integrated Primary Care Information database, containing electronic health records of 2.5 million patients from the Netherlands. Adults at risk for OA were included. Diagnosis of knee or hip OA (=exposure) and 58 long-term comorbidities (=outcome) were defined by diagnostic codes following the International Classification of Primary Care coding system. Time between the start of follow-up and incident diagnosis of OA was defined as unexposed, and between diagnosis of OA and the end of follow-up as exposed. Age and sex adjusted hazard ratios (HRs) comparing comorbidity rates in exposed and unexposed patient time were estimated with 99.9% confidence intervals (CI).

RESULTS

The study population consisted of 1,890,712 patients. For 30 of the 58 studied comorbidities, exposure to knee OA showed a HR larger than 1. Largest positive associations (HR with (99.9% CIs)) were found for obesity 2.55 (2.29-2.84) and fibromyalgia 2.06 (1.53-2.77). For two conditions a HR < 1 was found, other comorbidities showed no association with exposure to knee OA. For 26 comorbidities, exposure to hip OA showed a HR larger than 1. The largest were found for polymyalgia rheumatica 1.81 (1.41-2.32) and fibromyalgia 1.70 (1.10-2.63). All other comorbidities showed no associations with hip OA.

CONCLUSION

This study showed that many comorbidities were diagnosed more often in patients with knee or hip OA. This suggests that the management of OA should consider the risk of other long-term-conditions.

Changes to consultations and diagnosis of osteoarthritis in primary care during the COVID-19 pandemic

OBJECTIVE

General practitioners (GP) are often the first medical professionals to treat musculoskeletal complaints. Yet the impact of COVID-19 on primary care utilisation for musculoskeletal complaints is largely unknown. This study quantifies the impact of the pandemic on primary care utilisation for musculoskeletal complaints and specifically osteoarthritis (OA) in the Netherlands.

DESIGN

We extracted data on GP consultations in 2015-2020 from 118,756 patients over 45 years of age and estimated reductions in consultations in 2020 as compared to 5-year average. Outcomes were GP consultations for: any musculoskeletal complaints, knee and hip OA and complaints, newly diagnosed knee and hip OA/complaints.

RESULTS

The relative reductions in consultations ranged from 46.7% (95% CI: 43.9-49.3%) (all musculoskeletal consultations) to 61.6% (95% CI: 44.7-73.3%) (hip complaints) at the peak of the first wave, and from 9.3% (95% CI: 5.7-12.7%) (all musculoskeletal consultations) to 26.6% (95% CI: 11.5-39.1%) (knee OA) at the peak of the second wave. The reductions for new diagnoses were 87.0% (95% CI: 71.5-94.1%) for knee OA/complaints, and 70.5% (95% CI: 37.7-86.0%) for hip OA/complaints at the peak of the first wave, and not statistically significant at the peak of the second wave.

CONCLUSION

We observed 47% reduction in GP consultations for musculoskeletal disorders during the first wave and 9.3% during the second wave. For hip and knee OA/complaints, the reductions were over 50% during the first, and 10% during the second wave. This disruption may lead to accumulation of patients with severe OA symptoms and more requests for arthroplasty surgery.

Arthroscopic partial meniscectomy vs non-surgical or sham treatment in patients with MRI-confirmed degenerative meniscus tears: a systematic review and meta-analysis with individual participant data from 605 randomised patients

OBJECTIVE

To identify subgroups of patients with magnetic resonance imaging (MRI)-confirmed degenerative meniscus tears who may benefit from arthroscopic partial meniscectomy (APM) in comparison with non-surgical or sham treatment.

METHODS

Individual participant data (IPD) from four RCTs were pooled (605 patients, mean age: 55 (SD: 7.5), 52.4% female) as to investigate the effectiveness of APM in patients with MRI-confirmed degenerative meniscus tears compared to non-surgical or sham treatment. Primary outcomes were knee pain, overall knee function, and health-related quality of life, at 24 months follow-up (0-100). The IPD were analysed in a one- and two-stage meta-analyses. Identification of potential subgroups was performed by testing interaction effects of predefined patient characteristics (e.g., age, gender, mechanical symptoms) and APM for each outcome. Additionally, generalized linear mixed-model trees were used for subgroup detection.

RESULTS

The APM group showed a small improvement over the non-surgical or sham group on knee pain at 24 months follow-up (2.5 points (95% CI: 0.8-4.2) and 2.2 points (95% CI: 0.9-3.6), one- and two-stage analysis, respectively). Overall knee function and health-related quality of life did not differ between the two groups. Across all outcomes, no relevant subgroup of patients who benefitted from APM was detected. The generalized linear mixed-model trees did also not identify a subgroup.

CONCLUSIONS

No relevant subgroup of patients was identified that benefitted from APM compared to non-surgical or sham treatment. Since we were not able to identify any subgroup that benefitted from APM, we recommend a restrained policy regarding meniscectomy in patients with degenerative meniscus tears.

Reduced risk of serious pneumococcal infections up to 10 years after a dose of pneumococcal conjugate vaccine in established arthritis

BACKGROUND

To examine rates of serious pneumococcal infections up to 10 years after vaccination with 7-valent conjugated pneumococcal vaccine (PCV7) in patients with arthritis compared to non-vaccinated arthritis patients.

METHODS

In total, 595 adult arthritis patients (rheumatoid arthritis; RA = 342, 80 % women and spondylarthropathy; SpA = 253, 45 % women) received one dose of PCV7. Mean age/disease duration were 62/16 and 51/14 years, respectively. For each patient, 4 matched reference subjects were identified. At vaccination, 420 patients received bDMARDs (anti-TNF = 330, tocilizumab = 15, abatacept = 18, anakinra = 1, rituximab = 56). Methotrexate was given as monotherapy (n = 86) or in combination with bDMARD (n = 220). 89 SpA patients received NSAIDs without DMARD. The Skåne Healthcare Register was searched for ICD-10 diagnostic codes for pneumococcal infections (pneumonia, lower respiratory tract infection, septicemia, meningitis, septic arthritis) between January 2000 and December 2018. Frequency of infections after vs before vaccination were calculated (relative risks). Relative risk ratio (RRR) and relative risk reduction (1-RRR) were calculated comparing patients vs non-vaccinated references. Kaplan-Meier and Cox regression were used to investigate time to first event and predictors of infections.

RESULTS

Among vaccinated RA and SpA patients, there was a significant relative risk reduction of pneumonia and all serious infections; 53% and 46%, respectively. There was no significant difference in time to first pneumonia or all serious infections after vaccination between patients and references. Higher age, RA diagnosis and concomitant prednisolone were associated with infections.

CONCLUSION

One dose of pneumococcal conjugate vaccine may decrease risk of serious pneumococcal infection up to 10 years in patients with arthritis receiving immunomodulating treatment.

Chronic opioid use before and after exercise therapy and patient education among patients with knee or hip osteoarthritis

OBJECTIVE

To investigate changes in opioid use after supervised exercise therapy and patient education among knee or hip osteoarthritis patients with chronic opioid use.

METHOD

In this cohort study, we linked data from the Good Life with osteoArthritis in Denmark register (GLA:D®; standardised treatment program for osteoarthritis; January 2013 to November 2018) with national health registries. Among 35,549 patients, 1,262 were classified as chronic opioid users based on amount and temporal distribution of dispensed opioids the year before the intervention. We investigated changes in opioid use, measured as mg oral morphine equivalents (OMEQs), from the year before the intervention to the year after using generalized estimating equations.

RESULTS

We found a 10% decrease in mg OMEQs from the year before to the year after the intervention (incidence rate ratio [IRR]: 0.90, 95% confidence interval [CI]: 0.86, 0.94). Additional analyses suggested this decrease to be mainly attributable to regulatory actions targeting opioid prescribing during the study period (IRR among patients participating in the intervention before: 0.98 [95% CI: 0.89, 1.07] vs after: 0.83 [0.74, 0.93] regulatory actions). In a random general population sample of matched chronic opioid users, a similar opioid use pattern was observed over time, further supporting the impact of regulatory actions on the opioid use in the study population.

CONCLUSION

Among patients with knee or hip osteoarthritis and chronic opioid use, a standardised treatment program did not change opioid use when regulatory changes in opioid prescribing were taken into account.

Phase-contrast enhanced synchrotron micro-tomography of human meniscus tissue

OBJECTIVE

To investigate the feasibility of synchrotron radiation-based phase contrast enhanced micro-computed tomography (SR-PhC-μCT) for imaging of human meniscus. Quantitative parameters related to fiber orientation and crimping were evaluated as potential markers of tissue degeneration.

DESIGN

Human meniscus specimens from 10 deceased donors were prepared using different preparation schemes: fresh frozen and thawed before imaging or fixed and paraffin-embedded. The samples were imaged using SR-PhC-μCT with an isotropic voxel size of 1.625 μm. Image quality was evaluated by visual inspection and spatial resolution. Fiber voxels were defined using a grey level threshold and a structure tensor analysis was applied to estimate collagen fiber orientation. The area at half maximum (FAHM) was calculated from angle histograms to quantify orientation distribution. Crimping period was calculated from the power spectrum of image profiles of crimped fibers. Parameters were compared to degenerative stage as evaluated by Pauli histopathological scoring.

RESULTS

Image quality was similar between frozen and embedded samples and spatial resolutions ranged from 5.1 to 5.8 μm. Fiber structure, including crimping, was clearly visible in the images. Fibers appeared to be less organized closer to the tip of the meniscus. Fiber density might decrease slightly with degeneration. FAHM and crimping period did not show any clear association with histopathological scoring.

CONCLUSION

SR-PhC-μCT is a feasible technique for high-resolution 3D imaging of fresh frozen meniscus tissue. Further work is needed to establish quantitative parameters that relate to tissue degeneration, but this imaging technique is promising for future studies of meniscus structure and biomechanical response.

POS1524-HPR HPR 2020 GRANT. AWARENESS OF NON-PHARMACOLOGICAL AND NON-SURGICAL TREATMENTS FOR OSTEOARTHRITIS: A SURVEY OF PEOPLE WITH OSTEOARTHRITIS IN SWEDEN

Background

International clinical practice guidelines for the management of osteoarthritis (OA)1 2 recommend exercise, education and diet as first-line interventions since they are safe, low cost and reported to be effective, in reducing OA pain and disability, regardless of the severity of the disease. However, these treatments require high levels of adherence, which may be difficult to achieve. One of the possible reasons that can jeopardise patients’ adherence with first-line interventions for OA is the lack of awareness of the role that these treatments play in their care.

Objectives

To investigate the level of awareness of non-pharmacological and non-surgical treatments for hip and knee OA in a cohort of people with this disease in Sweden.

Methods

A cross-sectional, online survey-based study was conducted in Sweden. People with diagnosed knee or hip OA were recruited through social media outlets and patients’ associations. The survey was divided into two sections: (i) participants’ demographic and clinical characteristics (e.g. gender, age, income, work, height, weight, level of physical activity, previous surgeries, pain, level of disability) and (ii) a set of items with 22 treatments (e.g., weight advice, physical activity, drugs, supplements etc) where participants were asked to report whether each treatment was ‘recommended’, ‘optional’, ‘not recommended’, or ‘I don’t know’ - for the management of knee or hip OA. In the analyses, we grouped the 22 proposed treatments into ‘recommended’, ‘optional’, and ‘not recommended’ according to existing international guidelines.1 2 Based on the responses, participants were categorised as “aware” if they correctly identified all the treatments, “partially aware” if they correctly identified at least one treatment, and “not aware” if they did not correctly identify any of the treatments.

Results

Participants comprised 123 people with OA of the knee, hip or both (N=65, 22%; N=27, 22% and N= 33, 26% respectively). Their mean (SD) age was 60.3 (8.8) and 108 (88%) were women. Forty-eight (39%) were “aware” of the recommended treatments, 63 (50%) “partially aware” and 14 (11%) were “not aware”. Regarding the optional treatments, 2 (2%) were “aware”, 103 (82%) “partially aware” and 20 (16%) were “not aware”. For the treatments that were not-recommended, none was “aware”, while 69 (55%) and 56 (45%) were considered “partially aware” and “not aware”, respectively. Figure 1 summarises the responses of the participants to each treatment item.

Figure 1.

Participants’ responses to each treatment

Conclusion

Survey participants seem to be more aware of the recommended treatments than the optional and not-recommended ones. A more holistic approach in the education of people with OA should be pursued, providing them with a complete overview of the possible OA treatments. This would help patients identify the most appropriate treatment option for their OA and facilitate a shared decision-making with their health professionals.

References

[1]Bannuru RR, Osani MC, Vaysbrot EE, et al. OARSI guidelines for the non-surgical management of knee, hip, and polyarticular osteoarthritis. Osteoarthr Cartil. 2019;27:1578–89.

[2]Fernandes L, Hagen KB, Bijlsma JWJ, et al. EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis. Ann Rheum Dis. 2013;72:1125–35.

Acknowledgements

This work is part of the project funded by EULAR (European Alliance of Associations for Rheumatology) “HPR: The EULAR health professionals research grant 2020.”

Disclosure of Interests

None declared

OP0228 USE OF NON-STEROIDAL ANTI-INFLAMMATORY DRUGS AND RISK OF COMORBIDITIES IN PEOPLE WITH AND WITHOUT OSTEOARTHRITIS - A UK PRIMARY CARE DATABASE COHORT STUDY

Background

People with osteoarthritis (OA) are at higher risk of developing a wide array of comorbidities. Whether the use of non-steroidal anti-inflammatory drugs (NSAIDs) contributes to the increased risk of some incident comorbidities remains unknown.

Objectives

To examine the contribution of NSAIDs in the development of a wide range of comorbidities in people with and without OA.

Methods

This observational cohort study used the UK primary care Clinical Practice Research Datalink (CPRD) GOLD containing data on 20+ million people covering 937 practices. We identified 259,000 people with incident OA and 259,000 age (±2 years), sex, and practice matched controls at 1:1 ratio. Controls were assigned the same index date (the date of first diagnosis of OA) as cases for the start of follow-up. Both cases and controls were further divided into two groups according to NSAID prescriptions at any time after the index date. This allowed us to examine both the main effect of each exposure and interaction between OA and NSAID exposure after the index date. People with an NSAID prescription before the index date were excluded from the study. NSAID exposure was defined as at least two prescriptions within 90 days. Exposure status of each participant was assessed every six months as yes/no until the end of the study/outcome of interests/death/last data available, whichever came first. Comorbidities were grouped into 9 categories as cancer, cardiovascular disease (CVD), endocrine, psychological, renal, gastrointestinal (GI), genitourinary, hepatic, and neurological conditions. Propensity scores for the prescription of NSAIDs were calculated using a logistic regression model including age, sex, body mass index (BMI), musculoskeletal and pain related conditions covariates. The propensity score adjusted time varying exposure analysis was undertaken using a multivariate COX model and hazard ratio (HR) and 95% confidence intervals were calculated. Proportional hazard assumption was tested using Schoenfeld test. Smoking, alcohol, ever prescription of proton pump inhibitors (PPIs) and other comorbidities were included in the adjusted model. The additional contribution of NSAIDs and OA towards the incident comorbidity was estimated using addictive interaction methods. We also investigated the individual risk across non-selective, and COX-2 selective NSAIDs.

Results

The mean age was 59.4±12.8 years in people with OA and 60.2±12.8 years for controls with 57.7% being female. Nearly two thirds of people with OA were prescribed NSAIDs as defined, compared to one third in the control population. People with OA and exposed to NSAIDs had highest risk of developing psychological (1.51; 1.43,1.60), CVD (1.38; 1.33,1.43), cancer (1.34; 1.25,1.44), GI (1.25; 1.16,1.34) and renal (1.17; 1.11,1.24) comorbidities after adjusting for all the covariates and PPI drugs, compared to the non-OA and non-NSAID group. (Figure 1) Interaction between OA and NSAID was significant for cancer, GI, renal, hepatic, and neurological outcomes. Within people with OA, non-selective NSAIDs increased the risk of CVD (1.25; 1.20,1.30), cancer (1.11; 1.04,1.19), endocrine (1.15; 1.10,1.19), renal (1.19; 1.13,1.26) and psychological (1.21; 1.15,1.28) comorbidities, whereas COX-2 selective NSAIDs increased risk of incident CVD (1.34; 1.25,1.44), endocrine (1.13; 1.04,1.21), renal (1.25; 1.14,1.37), and psychological (1.21; 1.09,1.34) comorbidities.

Figure 1.

Hazard ratio of developing different comorbidities (reference group: no OA and no NSAIDs) OA- Osteoarthritis; NSAIDS- Non-steroidal anti-inflammatory drugs.

Conclusion

Use of NSAIDs among people with OA is associated with increased risk of a wide variety of comorbidities. Non-selective and COX-2 selective NSAIDs are both associated with increased risk of cardiovascular, renal, and psychological comorbidities.

Acknowledgements

We thank the Patient Research Participants (PRP) members Jenny Cockshull, Stevie Vanhegan, and Irene Pitsillidou for their involvement since the beginning of the project. We would like to thank the FOREUM for financially supporting the research.

Disclosure of Interests

Subhashisa Swain: None declared, Anne Kamps: None declared, Jos Runhaar: None declared, Andrea Dell’Isola: None declared, Aleksandra Turkiewicz: None declared, Danielle E Robinson: None declared, Victoria Y Strauss: None declared, Christian Mallen: None declared, Chang-Fu Kuo: None declared, Carol Coupland: None declared, Michael Doherty Consultant of: Consultant of: Advisory borads on gout for Grunenthal and Mallinckrodt, Grant/research support from: Michael Doherty Grant/research support from: AstraZeneca funded the Nottingham Sons of Gout study, Aliya Sarmanova: None declared, Daniel Prieto-Alhambra Speakers bureau: paid speaker services from Amgen and UCB Biopharma., Consultant of: His department has received advisory or consultancy fees from Amgen, Astellas, AstraZeneca, Johnson, and Johnson, and UCB Biopharma, Grant/research support from: Prof. Prieto-Alhambra’s research group has received grant support from Amgen, Chesi-Taylor, Novartis, and UCB Biopharma., Martin Englund: None declared, S.M.A. Bierma-Zeinstra: None declared, Weiya Zhang Speakers bureau: Speakers bureau: Bioiberica as an invited speaker for EULAR 2016 satellite symposium, Consultant of: Consultant of: Grunenthal for advice on gout management,

POS1132 PATTERNS OF JOINT SURGERY IN THE TEN YEARS PRIOR TO PRIMARY KNEE REPLACEMENT IN ENGLAND AND SWEDEN – A POPULATION-BASED CASE-CONTROL STUDY

Background

Primary knee replacement (KR) is an effective intervention for end-stage knee osteoarthritis (OA). However, there are no definitive recommendations for the timing at which patients should receive this surgery, potentially resulting in differences in referral patterns depending on geographical area or the clinicians‘ preferences.

Objectives

To investigate the prevalence of meniscus, knee ligament and knee synovial surgeries as well as knee osteotomy and hip replacement (HR) across the ten years preceding a KR in cases and controls in England and Sweden.

Methods

This was a multi-national, population-based, case-control study within England and Sweden. Cases underwent primary TKR and controls, matched using risk-set sampling by age, sex and practice/region, did not. Electronic healthcare databases were used; the Clinical Practice Research Datalink (CPRD) in England, and the Health Register of Skåne (Sweden’s southernmost region) in Sweden.

ICD-10 codes and KVÅ codes in Sweden and Medcodes (SNOMED CT (UK edition) and Read codes) in England were used to identify subjects aged ≥45 years who underwent primary KR between 1st January 2015 and 31st December 2019. Eligible cases had to be registered for ≥10 years prior to the primary KR (index date), and have no record of prior KR in that period.

Office of Population Censuses and Surveys (OPCS) codes in England and ICD-10 codes in Sweden were used to identify selected orthopaedic surgeries.

Meniscal (e.g. excision, resection, repair) and ligament surgery (e.g. ligament reconstruction, replacement, suture) were included, as well as osteotomy (e.g. angle, rotational or displacement osteotomy of the knee or lower leg). Hip replacement (HR) (any primary HR) was also included, to evaluate the rate at which patients undergoing KR also undergo further major arthroplasty in the years preceding this – The annual prevalence of having at least one recorded surgery for each type in each of the 10 years preceding KR was estimated using Poisson regression models and expressed per 1,000 people.

Results

We identified 6,337 and 47,010 subjects who underwent a knee replacement between 2015 and 2019 in southern Sweden and England, respectively (Table 1). Overall, the prevalence of all analysed surgeries was consistently lower in the controls with minimal trends detectable throughout follow-up in both England and Sweden (Figure 1).

Table 1.

demographic

SwedenEnglandCases(n=6,337)Controls(n=6,337)Cases(n=47,010)Controls(n=47,010)Age, mean (SD)69.0 (8.9)68.9 (9.1)69.6 (9.6)69.6 (9.6)Female Sex, n (%)3,585 (56.6%)3,585 (56.6%)26,154 (55.6%)26,154 (55.6%)Surgeries, n Hip replacement5623243,9331,889 Meniscus384448,659833 Ligaments1659011 Synovial1641536930 Osteotomy9831075

On the other hand, an increasing trend among the cases, signifying a higher prevalence of surgeries when nearing KR, was observed for HR and meniscal surgeries in both nations. The prevalence of HR was similar in England and southern Sweden at all-time points showing an increase most noticeable in the 3 years before KR. The prevalence of meniscus surgery in England was higher than the one observed in Sweden throughout the follow-up. Prevalence in England increased most noticeably in the four years prior to KR reaching 33.2 (95%CI 31.6, 34.9) surgeries per 1,000 people in the year preceding KR. In Sweden, the prevalence of meniscus surgery remained between four and eight surgeries per 1,000 people until the last year prior to KR when the prevalence increased to 13.8 (95%CI 11.9, 16.2) surgeries per 1,000 people.

Conclusion

HR and meniscal surgeries are common procedures that a person is likely to have experienced in the ten years prior to a KR. Comparing England and southern Sweden, we noticed similar prevalence and trends for what concerns HR suggesting similar practice in the two healthcare systems. Meniscus surgeries were more frequently utilised in England. Nevertheless, in both countries, a marked increase in the prevalence of this surgery was observed in the last years prior to the KR.

Disclosure of Interests

None declared

Opioid use prior to total knee replacement: comparative analysis of trends in England and Sweden

OBJECTIVES

To describe and compare trends in the frequency of opioid prescribing/dispensing in English and Swedish patients with osteoarthritis prior to total knee replacement (TKR).

METHODS

49,043 patients from an English national database (Clinical Practice Research Datalink) and 5,955 patients from the Swedish Skåne Healthcare register undergoing TKR between 2015 and 2019 were included, alongside 1:1 age-, sex-, and practice (residential area) matched controls. Annual prevalence and prevalence rates ratio (PRR) of opioid prescribing/dispensing (any, by strength) in the 10 years prior to TKR (or matched index date for controls) were estimated using Poisson regression.

RESULTS

In England and Sweden, the prevalence of patients with osteoarthritis receiving any opioid prior to TKR increased towards the date of surgery from 24% to 44% in England and from 16% to 33% in Sweden. Prescribing in controls was stable, resulting in an increasing PRR (1.6-2.7) between 10 and 1 years prior to index date in both countries. No relevant cohort or period effect was observed in either country. Prevalence of opioid prescribing was higher in English cases and controls; weaker opioids were more commonly prescribed in England, stronger opioids in Sweden.

CONCLUSIONS

Temporal prevalence patterns of opioid prescribing between cases and controls are similar in England and Sweden. Opioids are still commonly used in TKR cases in both countries highlighting the lack of valid alternatives for OA pain management.

POS1124 EVALUATION OF COMORBIDITY PATTERNS AND IDENTIFICATION OF SUB-GROUPS IN PATIENTS DIAGNOSED WITH HIP OSTEOARTHRITIS IN 94,720 PATIENTS FROM SPAIN

Background

Osteoarthritis (OA) patients are more likely to have other comorbidities (Swain, Sarmanova et al. 2020). Improving the understanding of comorbidity profiles of OA patients may lead to improvement in their clinical care.

Objectives

To identify sub-groups in patients diagnosed with hip OA using patterns of comorbidity.

Methods

Routinely-collected data of individuals ≥18 years with an incident diagnosis of hip OA (baseline/time of diagnosis), with at least 1 year of follow-up in SIDIAP (Information System for Research in Primary Care, a primary case database from Spain) were collected from January 1st 2006 to June 31st 2020. Those with soft-tissue disorders or other bone/cartilage diseases at the same joint in the year prior/after baseline were excluded. Comorbidities associated with OA in the literature and present in ≥1% of the study population were included. Clusters of comorbidities were identified at baseline using latent class analysis (LCA), a soft clustering method that classifies individuals according to the distribution of their measured items. The number of clusters or sub-groups within the study population was decided by comparing goodness of fit parameters (CAIC, BIC, ABIC) and log-likelihood changes of models from 2 to 8 clusters. The selected model was externally evaluated by a survival analysis assessing 10 years mortality within each cluster, where the weight of the posterior probability was used as a probability of sampling weight.

Results

We identified 94,720 individuals with an incident diagnosis of hip OA, 56.3% women and 43.7% men, with a mean age (SD) of 67.2 (13.1) years. We selected the LCA model with 5 clusters that could be described as: healthier (lower prevalence of all comorbidities than average in the cohort), multimorbidity (higher prevalence of all comorbidities, multiple comorbidities), back/neck pain plus mental health (B/N-mental), cardiovascular disease (CVD), and metabolic syndrome (MetS) (Figure 1). Cox regression (HR [95CI%]) showed higher mortality risk for multimorbidity (3.76 [3.70-3.83]), CVD (1.56 [1.53-1.59]) and MetS (4.56 [4.35-4.78]), compared to healthy. No difference was observed for B/N-mental cluster.

Figure 1.

Distribution of comorbidities within each cluster using latent class analysis. Clusters were described as Healthier, Multimorbidity, B/N-mental, CVD and MetS. Black horizontal lines represent the prevalence of the comorbidity before the clusterization. Abbreviations: Healthier, lower prevalence of all comorbidities; Multimorbidity, higher prevalence of all comorbidities; B/N-mental, back/neck pain plus mental health disorders; CVD, cardiovascular disease; Met, metabolic syndrome; Bhp, benign prostate hypertrophy; Chd, chronic heart disease; Chf, chronic heart failure; Ckd, chronic kidney disease; Copd, chronic obstructive pulmonary disease; Gbs, gall bladder stone; Gerd, gastroesophageal reflux disease; Ibd, inflammatory bowel disease; Ovd, other vessel diseases; Substance, substance abuse.

Conclusion

Clustering of co-morbidities in hip OA patients at the time of diagnosis has the potential to detect sub-groups of hip OA patients who might require additional care.

References

[1]Swain, S., A. Sarmanova, C. Coupland, M. Doherty and W. Zhang (2020). “Comorbidities in Osteoarthritis: A Systematic Review and Meta-Analysis of Observational Studies.” Arthritis Care Res (Hoboken) 72(7): 991-1000.

Acknowledgements

We thank the Patient Research Participants (PRP) members Jenny Cockshull, Stevie Vanhegan, and Irene Pitsillidou for their involvement since the beginning of the project. We would like to thank the FOREUM for financially supporting the research.

Disclosure of Interests

None declared

OP0225 RISK OF COMORBIDITY FOLLOWING OSTEOARTHRITIS DIAGNOSIS: A COHORT STUDY IN THE NETHERLANDS FROM THE FOREUM* INITIATIVE

Background

Osteoarthritis (OA) is a common and disabling disease that places a significant burden on both patients and health care systems. Previous studies have already shown that patients with OA have a higher risk of developing comorbidities. However, many focused on one or a few conditions only, or did not consider the chronology of the disease onset relative to OA.

Objectives

To determine the risk of physician-diagnosed comorbidity following the diagnosis of knee or hip OA, using electronic health records in the Netherlands.

Methods

A cohort study was conducted using the Integrated Primary Care Information (IPCI) database, an electronic health record database with medical records of 2.5 million patients from Dutch general practice. The study population consisted of patients aged 18 years or older, that were at risk for incident OA and comorbidity. Diagnosis of knee or hip OA (i.e. exposure) was defined as the first registration of the corresponding diagnostic code from the International Classification of Primary Care (ICPC) coding system in the medical record. Fifty-eight long-term comorbidities (i.e. outcome) were selected and defined by their corresponding ICPC codes.

Patients’ follow-up started after registration in the database, and ended at the diagnosis date of the comorbidity (i.e. event), or at deregistration, death or at December 31st, 2019 (i.e. censoring), whichever came first. Exposure to knee or hip OA was a time-varying exposure: time between the start of follow-up and diagnosis of OA was defined as unexposed time, and between diagnosis of OA and the end of follow-up as exposed time. Patients’ age was used as time axis to correct for age non-linearly. Sex-adjusted hazard ratios (HRs) comparing exposed and unexposed patient status were estimated with 99.9% confidence intervals (CI).

Results

The study population consisted of 1,890,712 patients. For 11 of the 58 studied comorbidities exposure to knee OA showed a statistically significant HR larger than 1, indicating an increased risk of being diagnosed with these comorbidities after a diagnosis of knee OA. For none of the comorbidities there was a statistically significant negative association (HR<1) with exposure to knee OA. For 7 comorbidities exposure to hip OA showed a statistically significant HR larger than 1. Again, for all other comorbidities the HR of hip OA was non-significant. For an overview of the statistically significant positive associations see Table 1.

Table 1.

Comorbidities with significant HRs of exposure to knee or hip OA

Knee OAHip OAComorbidityHR99.9% CIComorbidityHR99.9% CIAnemia1.331.091.64Anemia1.291.021.63Back pain1.281.041.57Atrial fibrillation1.461.141.88Cataract1.271.021.59Fibromyalgia6.091.2529.53Chronic kidney disease1.301.061.59Peripheral vascular disease1.641.092.49Coronary heart disease1.341.031.75Sleeping disorder1.441.101.87Gout1.431.012.03Solid malignancy1.321.111.55Hearing loss1.341.001.79Spinal disc herniation2.031.462.83Neck pain1.581.162.16Obesity2.021.063.83Sleeping disorder1.331.041.69Thromboembolic disease1.401.011.94

Conclusion

This study showed that certain comorbidities were diagnosed more often in patients exposed to knee or hip OA, and none were less frequently diagnosed in patients exposed OA. This suggests that the management of OA should consider the risk of other long-term-conditions and that further research on causality between OA and comorbidity is needed.

References

[1]*https://www.foreum.org/projects.cfm?projectid=159

Acknowledgements

We thank the Patient Research Participants members Jenny Cockshull, Stevie Vanhegan, and Irene Pitsillidou for their involvement in the project. We would like to thank the FOREUM for financially supporting the research.

Disclosure of Interests

None declared

Are structural abnormalities on knee MRI associated with osteophyte development? Data from the Osteoarthritis Initiative

OBJECTIVE

To assess which structural abnormalities on knee MRI are associated with development of osteophytes in middle-aged subjects without radiographic knee osteoarthritis.

DESIGN

We included subjects from the Osteoarthritis Initiative, aged 40-55 years, Kellgren & Lawrence grade 0 in both knees, and knee MRIs from both knees available at baseline, 24, 48 and 72 months. Structural exposures on MRI assessed using MOAKS included cartilage damage, bone marrow lesions, meniscal tear, meniscal extrusion, and Hoffa/effusion synovitis. We assessed whether each structural exposure was associated with the development of osteophytes on MRI in the medial and lateral tibiofemoral, and patellofemoral compartment. We estimated hazard ratios (HR) including 95% confidence intervals (CI) for osteophyte development using a mixed complementary log-log regression model adjusted for age, sex, and body mass index.

RESULTS

We included 680 knees from 340 subjects with a mean (SD) age of 50 years (3.0), and 51% men. In the medial tibiofemoral compartment, the absolute risk of osteophyte development in the first 24-month period was 4% in knees without, and 15% in knees with medial meniscal tear. Corresponding adjusted HR was 6.6 (95%CI = 3.4-12.9). In the lateral tibiofemoral compartment, the adjusted HR for developing osteophytes having a lateral meniscal tear was 3.3 (95%CI = 1.3-8.4). In the patellofemoral compartment, patellofemoral cartilage damage was most clearly associated with developing osteophytes (HR = 2.6, 95%CI = 1.8-3.7).

CONCLUSIONS

Meniscal tear seem to be the strongest structural risk factor for the development of tibiofemoral osteophytes, and patellofemoral cartilage damage for the development of patellofemoral osteophytes, respectively. Local biomechanical factors are important in early osteophyte development.

Variability in end-of-life healthcare use in patients with osteoarthritis: a population-based matched cohort study

PURPOSE

To investigate the patterns of healthcare use (HCU) at the last year of life in persons with osteoarthritis (OA).

METHODS

Using linked registers, we identified persons aged≥ 65 years who died during 2003-2014 and were resided in the Skåne region during 5-year prior to death. Among these, we randomly matched decedents with a principal OA diagnosis prior to the last year of life (OA cohort, n = 17,993) with up to 4 comparators without OA by sex, age at death, and year of death (n = 59,945). We measured monthly HCU for each decedent during last year of life and applied two-part regression models to estimate HCU attributable to OA. Group-based trajectory modelling (GBTM) was used to detect distinct trajectories of HCU within the OA cohort.

RESULTS

During last 12-month of life, each person with OA had, on average, 2.5 (95% CI 2.2, 2.7) excess healthcare consultations and 1.8 (95% CI 1.3, 2.2) more inpatient days than those without OA. While both cohorts observed increasing trends in HCU towards death, excess healthcare consultations attributable to OA declined and inpatient days increased as death approached. For both healthcare consultations and inpatient days, GBTM identified four distinct trajectory classes. While underlying cause of death and age were the most important predictors of class membership, the overall predictive accuracy was poor.

CONCLUSION

OA was associated with excess HCU especially hospital-based care during the last year of life. However, there seem to be distinct trajectory classes within the OA patient population.

Importance of patellofemoral and tibiofemoral cartilage lesions on trajectory of self-reported outcomes in patients at high risk of knee OA: 4-6 years follow-up of patients undergoing meniscal surgery

OBJECTIVE

We evaluated whether patient-reported outcome trajectories (i.e., changes over time) differed by intraoperative compartmental cartilage lesion pattern over 4-6 years following arthroscopic meniscal surgery.

METHODS

In this ancillary study of the Knee Arthroscopy Cohort Southern Denmark cohort, we intraoperatively categorized cartilage lesions as isolated patellofemoral, isolated tibiofemoral, or combined patellofemoral/tibiofemoral. Participants completed the Knee injury and Osteoarthritis Outcome Score (KOOS) pre-operatively, at 3 and 12 months, and at 4-6 years post-operatively and reported overall satisfaction at final follow-up. Our main outcome was KOOS₄ (grand mean of four subscale means). We evaluated whether KOOS₄ scores changed over time according to cartilage lesion patterns using adjusted mixed linear regression. We also estimated probability of treatment satisfaction using logistic regression.

RESULTS

Of 630 participants with complete cartilage scores, 280 (44%) were women, mean (standard deviation) age was 49 (13) years, and BMI was 27.3 (4.4) kg/m². KOOS₄ scores at baseline were slightly lower in all lesion groups compared to the no lesion group, yet only the combined group was statistically significantly lower. KOOS₄ trajectories were similar across cartilage lesion patterns, but by final follow-up, adjusted mean KOOS₄ scores were 6.8 (95% CI 2.2, 11.4) to 9.8 (1.1, 18.5) points lower in groups with cartilage lesions compared to the no lesion group. Probability of patient-reported satisfaction did not differ statistically by group.

CONCLUSIONS

Though KOOS₄ scores were slightly lower in groups with arthroscopically assessed cartilage lesions compared to the no lesion group, trajectories were similar across all groups.

The heritability of doctor-diagnosed traumatic and degenerative meniscus tears

OBJECTIVE

To estimate the genetic contribution to traumatic and degenerative meniscus tears for men and women across the lifespan.

METHODS

We linked the Swedish Twin Register with individual-level national healthcare data to form a 30-year, population-wide, longitudinal twin cohort. To study genetic contribution to meniscus tears, we estimated the heritability and familial risk using incident traumatic and degenerative tear diagnostic codes in a cohort of 88,414 monozygotic and dizygotic twin-pairs, aged ≥17 years.

RESULTS

During follow-up, 3,372 (3.8%) of 88,414 twins were diagnosed with a traumatic or degenerative meniscus tear. The heritability was 0.39 (95% CI = 0.32-0.47) for men and 0.43 (95% CI = 0.36-0.50) for women, and did not vary by age. Environmental factors that were unique to each twin in a pair explained a greater proportion of the variance than genetic factors, both for men (0.61, 95% CI = 0.53-0.68) and women (0.57, 95% CI = 0.50-0.64). Separate analyses of traumatic vs degenerative meniscus tears yielded similar results.

CONCLUSION

For the first time, we have estimated the genetic contribution to doctor-diagnosed meniscus tears using a twin study design. We found a relatively low to modest heritability for meniscus tears (∼40%). The heritability was also fairly stable over the lifespan, and equal in both men and women. Our findings suggest that environmental risk factors are a more important contributor to both traumatic and degenerative doctor-diagnosed meniscus tears than genetic factors.

POS0160-HPR THE CARE PROCESS OF HIP AND KNEE OSTEOARTHRITIS: GIVING AN ACCOUNT OF PATIENTS’ EXPERIENCE

Background:

The care process is often a complex and intimate process experienced by patients. Osteoarthritis (OA) care is usually characterised by multimodal interventions that consider the broader array of symptoms and functional limitations and often require a high level of patients’ compliance. Despite efforts to improve the quality of care of patients suffering from OA, and the publication of state-of-the-art clinical practice guidelines [1], the quality of the care process, as experienced by patients, seems to be suboptimal [2]. Hence, it is essential to investigate how patients experience this process to highlight potential elements that can enhance or spoil it to optimise the care quality.

Objectives:

To explore the patients’ experience of the received OA care process.

Methods:

Qualitative study, 10 semi-structured interviews were performed. The interview guide was created by a pool of healthcare professionals (physiotherapists, psychologists, nurses) and expert patients. It investigated the emotional experience, beliefs, expectations, perceived barriers and facilitators towards conservative treatments perceived by patients suffering from OA. The interviews lasted approximately one hour, were transcribed verbatim and analysed independently by two authors, who labelled their core parts to find categories and subcategories. A theme-based analysis was performed following an ecological paradigm, naturalistic epistemology, philosophy of phenomenological research.

Results:

Our analysis revealed 7 main categories with several subcategories (Fig. 1). 1) Uncertainty as some patients perceived treatment choice not to be based on medical evidence “there is an almost religious way of thinking on how to deal with the pathology. It is not an exact science when you choose the physicians you choose the treatment”. 2) Relationship with the self and the others as some patients did not feel understood or even shameful and hopeless about their condition. 3) Patients’ and Health Professionals’ beliefs about the pathology management where common thoughts were the perceived (ab)use of passive therapies, the movement as something dangerous and that OA is “something that you try to resist to, but (surgery) is your destiny”. 4) facilitators and 5) barriers of the adherence to therapeutic exercise that revolve around the cost of the therapy, the time needed and the willingness to change life habits. 6) Patients’ attitudes towards pathology in which the oldest patients perceive OA as “something I have to accept since I am getting old” and the youngest as “Something I have to fight”. 7) Relationship with food in which diet is seen as something that “you force yourself to follow” which is useful only to lose weight and not to preserve a high health status and where overeating is used “to eat your feelings”.

Figure 1.

Categories and Subcategories stemmed from the analysis of the patients’ interviews

Conclusion:

Patients suffering from hip and knee OA seem to experience an uncertain care process. The lack of clear explanations and the attitude towards conservative treatment, which is considered as “a pastime while waiting for surgery,” fosters the importance of providing patients with adequate information about the treatment, to shift their beliefs and improve their awareness. This will enhance a patient-centred and shared decision-making treatments.

References:

[1]Fernandes L, Hagen KB, Bijlsma JWJ, et al. EULAR recommendations for the non-pharmacological core management of hip and knee osteoarthritis. Ann. Rheum. Dis. 2013;72:1125–35.

[2]Basedow M, Esterman A. Assessing appropriateness of osteoarthritis care using quality indicators: a systematic review. J Eval Clin Pract 2015;21:782–9.

Acknowledgements:

This work is part of the project funded by EULAR Health Professionals Research Grant 2020.

Disclosure of Interests:

None declared

AB0678 RATES OF SURGICAL PROCEDURES OF THE KNEE AND HIP DURING THE “FIRST WAVE” OF COVID 19 IN SWEDEN

Background:

Many countries imposed lockdowns in March 2020, in anticipation of the “first wave” of COVID-19 and the massive healthcare resources required to meet its acute medical needs. Sweden adopted a different strategy to contain the epidemic, opting for non-binding recommendations. Nonetheless, elective and acute surgical procedures in health care may have been affected.

Objectives:

To investigate the effect of the “first-wave” of COVID-19 and the government’s response in Sweden on the rates of total joint replacements (TJR), arthroscopies, and fracture surgeries of the knee and hip.

Methods:

We used register data for the entire population of Skåne, the southernmost region in Sweden with 1.3 million inhabitants (13% of the total Swedish population). We identified all residents aged ≥18 years who between 1st January 2015 and 31st November 2020 underwent any of the following surgical procedures of the knee or hip: TJR (TJR due to fracture excluded), arthroscopy, and surgery due to fracture (including TJR). To demarcate pre-event and post-event periods, we established a differentiation point corresponding to mid-March 2020, the timepoint at which the the Swedish Public Health Agency began recommending social distancing, working from home, distance learning for secondary schools and universities,. At the aggregate level, we modelled the number of surgeries per 10,000 adults from January 2015 up to September 2020. We did an interrupted time-series (ITSA) analysis using segmented ordinary least-squares regression to estimate changes in the levels and trends of surgical procedures compared to pre-COVID-19 levels, adjusting for seasonal variations. The month of March was treated as a “phase-in” period to give time for the new recommendations to be implemented. In addition, we estimated the absolute and relative difference (with its 95% confidence interval [CI]) between the predicted and the counterfactual scenario in the monthly number of surgeries from April 2020, where the counterfactual is the rate of surgery that would have been expected if COVID-19 had not happened. To account for the possibility that other co-occurring events may be responsible for the observed changes, we assessed changes in the number of surgeries due to fractures, which are normally treated as emergencies that cannot be cancelled or rescheduled, and thus should be less affected, at least by policies at the hospital level.

Results:

We identified a total of 20,831 TJRs, 12,156 arthroscopies and 15,041 fracture surgeries of the knee or hip over the study period. The monthly rate of surgeries and ITSAs are presented in Figure 1, with the pre-COVID period starting from February 2019 for readability (Figure 1). The results suggest that in April 2020, there was a decrease of 2.08 (95%CI 1.81; 2.35) TJRs per 10,000 adults which corresponds to a decrease of 74% (95%CI 65%; 85%) when compared to the counterfactual scenario. This was followed by a positive trend signifying a monthly increase of 0.36 (95%CI 0.31; 0.40) TJRs per 10,000 adults. The rate of arthroscopies followed a similar pattern with a decrease of 0.55 (95%CI 0.39; 0.71) arthroscopies per 10,000 adults in April, which corresponds to a 49% decrease (95%CI 28%; 63%) followed by a positive trend signifying a monthly increase of 0.11 (95%CI 0.07; 0.15) arthroscopies per 10,000 adults. The rate of surgery due to knee or hip fractures showed no decrease in April and was followed by a negative trend signifying a monthly decrease of 0.03 (95%CI 0.002; 0.04) surgeries per 10,000 adults.

Conclusion:

In Sweden, we observed a marked decrease in the number of typical elective knee and hip surgeries such as TJRs and arthroscopies, following the government’s response to Covid-19. We then observed a slow but steady recovery that brought the rates of procedures towards expected levels by Fall 2020, before the “second wave” hit the country. The number of acute fracture surgeries showed no sharp drop, instead showing a steady and slow decline potentially due to reduction in commuting and in physical activities linked to recommendations of social

Disclosure of Interests:

None declared

Is meniscal status in the anterior cruciate ligament injured knee associated with change in bone surface area? An exploratory analysis of the KANON trial

OBJECTIVES

To study bone shape changes as a potential early feature of post-traumatic structural knee OA development, we estimated the association between meniscal status in the anterior cruciate ligament (ACL) injured knee and longitudinal condyle changes in bone surface area.

DESIGN

We used data from the KANON trial, including 121 young ACL-injured adults. We obtained baseline and 2-year follow-up knee MRIs. Our outcome was change in the bone surface areas (mean mm2, log-transformed) in 4 locations (femur, tibia, patella, and trochlea femur) in the medial and lateral compartment from baseline to 2 years. Meniscal pathology was defined as both present at baseline and newly developed (i.e., incident or progressed) using ACLOAS. We used multilevel linear regression adjusted for baseline bone area, age, sex, body mass index, treatment arm (i.e., early or optional delayed ACL reconstruction), and location. We analyzed medial and lateral compartment separately. We present results as percentage (%) bone area change difference with 95% confidence intervals (CI).

RESULTS

We analyzed 109 subjects (median 27 (18-36) years, 83% men) due to missing MRI information. The bone surface area increased on average by ∼2% over 2 years. The differences between knees with and without baseline meniscal pathology were 1.1% (95%CI 0.0-2.3%) and 1.4% (95%CI 0.6-2.2%) in the medial and lateral compartment, respectively, and 1.2% (95%CI 0.3-2.0%) and 1.3% (95%CI 0.6-2.0%) for medial and lateral newly developed pathology, respectively.

CONCLUSION

Our finding of ∼1% increase bone area in compartment with meniscal pathology suggests a potentially important association between meniscal integrity and early bone surface area changes after ACL injury. Trial registration number ISRCTN 84752559.

Quantitative three-dimensional collagen orientation analysis of human meniscus posterior horn in health and osteoarthritis using micro-computed tomography

OBJECTIVE

Knee osteoarthritis (OA) is associated with meniscal degeneration that may involve disorganization of the meniscal collagen fiber network. Our aims were to quantitatively analyze the microstructural organization of human meniscus samples in 3D using micro-computed tomography (μCT), and to compare the local microstructural organization between OA and donor samples.

METHOD

We collected posterior horns of both medial and lateral human menisci from 10 end-stage medial compartment knee OA patients undergoing total knee replacement (medial & lateral OA) and 10 deceased donors without knee OA (medial & lateral donor). Posterior horns were dissected and fixed in formalin, dehydrated in ascending ethanol concentrations, treated with hexamethyldisilazane (HMDS), and imaged with μCT. We performed local orientation analysis of collagenous microstructure in 3D by calculating structure tensors from greyscale gradients within selected integration window to determine the polar angle for each voxel.

RESULTS

In donor samples, meniscus bundles were aligned circumferentially around the inner border of meniscus. In medial OA menisci, the organized structure of collagen network was lost, and main orientation was shifted away from the circumferential alignment. Quantitatively, medial OA menisci had the lowest mean orientation angle compared to all groups, -24° (95%CI -31 to -18) vs medial donor and -25° (95%CI -34 to -15) vs lateral OA.

CONCLUSIONS

HMDS-based μCT imaging enabled quantitative analysis of meniscal collagen fiber bundles and their orientations in 3D. In human medial OA menisci, the collagen disorganization was profound with overall lower orientation angles, suggesting collagenous microstructure disorganization as an important part of meniscus degradation.

Trajectory of excess healthcare consultations, medication use, and work disability in newly diagnosed knee osteoarthritis: a matched longitudinal register-based study

PURPOSE

To estimate the excess healthcare use and work disability attributable to knee osteoarthritis (OA) in the first 5 years following diagnosis.

METHODS

Among individual aged 40-80 years who resided in Skåne on 31^st December 2008, we identified those with a main diagnosis of knee OA during 2009-2014 and no previous diagnosis of any OA from 1998 (n = 16,888). We created a comparison cohort matched (1:1) by sex, age, and municipality from individuals with no OA diagnosis (at any site) during 1998-2016. We compared healthcare use and net disability days for 60 months following diagnosis between the two groups. We applied a survival-adjusted regression technique controlling for sociodemographic characteristics as well as pre-diagnosis outcome and comorbidity.

RESULTS

The estimated 5-year incremental effects of knee OA per-patient were 16.8 (95% CI: 15.8, 17.7) healthcare consultations, 0.7 (0.4, 1.1) inpatient days, 420 (372, 490) defined daily dose of prescribed medications, and 21.8 (15.2, 30.0) net disability days. Primary care consultations constituted about 73% of the excess healthcare consultations. Most of these incremental effects occurred in the first year after diagnosis. Better survival in the knee OA group accounted for 0.7 (95% CI: 0.5, 0.8) and 1.4 (0.7, 2.6) of the excess healthcare consultations and net disability days, respectively. Both estimated total and incremental resources use were generally greater for women than men with knee OA.

CONCLUSION

Knee OA was associated with considerable excess healthcare use and work disability independent of pre-diagnosis resources use, comorbidity, and sociodemographic characteristics.

Proteomic comparison of osteoarthritic and reference human menisci using data-independent acquisition mass spectrometry

OBJECTIVE

Recent research in knee osteoarthritis (OA) highlights the role of the meniscus in OA pathology. Our aim was to compare the proteomes of medial and lateral menisci from end-stage medial compartment knee OA patients, with reference menisci from knee-healthy deceased donors, using mass spectrometry.

DESIGN

Tissue plugs of Ø3 mm were obtained from the posterior horns of the lateral and medial menisci from one knee of 10 knee-healthy deceased donors and 10 patients undergoing knee replacement. Proteins were extracted and prepared for mass spectrometric analysis. Statistical analysis was conducted on abundance data that was log₂-transformed, using a linear mixed effects model and evaluated using pathway analysis.

RESULTS

We identified a total of 835 proteins in all samples, of which 331 were included in the statistical analysis. The largest differences could be seen between the medial menisci from OA patients and references, with most proteins showing higher intensities in the medial menisci from OA patients. Several matrix proteins, e.g., matrix metalloproteinase 3 (MMP3) (4.3 times higher values [95%CI 1.8, 10.6]), TIMP1 (3.5 [1.4, 8.5]), asporin (4.1 [1.7, 10.0]) and versican (4.4 [1.8, 10.9]), all showed higher abundance in medial menisci from OA patients compared to medial reference menisci. OA medial menisci also showed increased activation of several pathways involved in inflammation.

CONCLUSION

An increase in protein abundance for proteins such as MMP and TIMP1 in the medial menisci from OA patients suggests simultaneous activation of both catabolic and anabolic processes that warrants further attention.

Development of osteoarthritis in patients with degenerative meniscal tears treated with exercise therapy or surgery: a randomized controlled trial

OBJECTIVE

To evaluate progression of individual radiographic features 5 years following exercise therapy or arthroscopic partial meniscectomy as treatment for degenerative meniscal tear.

DESIGN

Randomized controlled trial including 140 adults, aged 35-60 years, with a magnetic resonance image verified degenerative meniscal tear, and 96% without definite radiographic knee osteoarthritis. Participants were randomized to either 12-weeks of supervised exercise therapy or arthroscopic partial meniscectomy. The primary outcome was between-group difference in progression of tibiofemoral joint space narrowing and marginal osteophytes at 5 years, assessed semi-quantitatively by the OARSI atlas. Secondary outcomes included incidence of radiographic knee osteoarthritis and symptomatic knee osteoarthritis, medial tibiofemoral fixed joint space width (quantitatively assessed), and patient-reported outcome measures. Statistical analyses were performed using a full analysis set. Per protocol and as treated analysis were also performed.

RESULTS

The risk ratios (95% CI) for progression of semi-quantitatively assessed joint space narrowing and medial and lateral osteophytes for the surgery group were 0.89 (0.55-1.44), 1.15 (0.79-1.68) and 0.77 (0.42-1.42), respectively, compared to the exercise therapy group. In secondary outcomes (full-set analysis) no statistically significant between-group differences were found.

CONCLUSION

The study was inconclusive with respect to potential differences in progression of individual radiographic features after surgical and non-surgical treatment for degenerative meniscal tear. Further, we found no strong evidence in support of differences in development of incident radiographic knee osteoarthritis or patient-reported outcomes between exercise therapy and arthroscopic partial meniscectomy.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT01002794).

OP0280 TEMPORAL TRENDS OF OPIOID USE AMONG INCIDENT OSTEOARTHRITIS PATIENTS IN CATALONIA, 2007-2016: A POPULATION-BASED COHORT STUDY

Background:

Opioids are not recommended as first-line treatments for chronic pain management in osteoarthritis (OA), but recent data suggest they are commonly used in routine practice in North America and northern Europe.

Objectives:

To characterise the secular trends of opioid and strong opioids use in patients with incident OA from 2007 to 2016, and to explore the impact of patient characteristics on the use of opioid/s for OA.

Methods:

Data was obtained from the SIDIAP (The System for the Development of Research in Primary Care) database, which contains primary care records and pharmacy dispensing data for 80 % of the population in Catalonia (~ 6 million people). All persons aged 18 or older at the beginning of each calendar year with an incident OA diagnosis (including both peripheral and central joints) in the study period were included. Index date was the date of first OA diagnosis, and the observation period of opioid use was 1-year after index date. Opioids considered included codeine, tramadol, fentanyl, and morphine, with the latter three classified as strong opioids. The period prevalence of any opioid use was estimated in whole and sub-population stratified by sex, age, socio-economic status (U1 – U5, higher values of the indicator equivalent to deprivation) and residence area (rural/urban).

Results:

The 1-year prevalence of any opioid use among incident OA patients was around 15% from 2007 to 2012. After that, this figure grew by 10% approaching 25% in 2016. However, strong opioid use increased continuously to nearly triple, from 8% in 2007 to 20% in 2016. The different subgroups followed similar trends over time, with women 4% higher than men, oldest 10% higher than youngest, most deprived 6% higher than least deprived, and rural 1% higher than urban.

Conclusion:

The use of opioids (and especially strong opioids) has substantially increased in recent years among newly diagnosed OA patients in Catalonia. Our findings call for urgent action for safe opioid prescribing to avoid opioid abuse in OA patients especially amongst older women living in deprived areas.

Figure 1.

Trends of 1-year prevalence of opioid/s use among incident OA patients, whole and subgroup population.

Disclosure of Interests:

Junqing Xie: None declared, Aleksandra Turkiewicz: None declared, Gary Collins: None declared, Martin Englund Consultant of: Advisory Board 1 day (2019) Pfizer (Tanezumab)., Victoria Y Strauss: None declared, Carlen Reyes: None declared, Daniel Prieto-Alhambra Grant/research support from: Professor Prieto-Alhambra has received research Grants from AMGEN, UCB Biopharma and Les Laboratoires Servier, Consultant of: DPA’s department has received fees for consultancy services from UCB Biopharma, Speakers bureau: DPA’s department has received fees for speaker and advisory board membership services from Amgen

Molecular and imaging biomarkers of local inflammation at 2 years after anterior cruciate ligament injury do not associate with patient reported outcomes at 5 years

OBJECTIVE

To estimate the association between molecular or imaging inflammatory biomarkers at 2 years after anterior cruciate ligament (ACL) injury and patient-reported outcomes at 5 years.

METHODS

For 116 ACL-injured patients, molecular biomarkers of inflammation (synovial fluid and serum cytokines) and Hoffa- and effusion-synovitis as visualized on magnetic resonance imaging (MRI) were assessed 2 years post-injury. Knee injury and Osteoarthritis Outcome Score (KOOS) and SF-36 were assessed at 2 and 5 years. We used multiple imputation to handle biomarker values that were below the level of detection or missing, and linear regression for statistical analyses.

RESULTS

None of the synovial fluid cytokines or imaging biomarkers of inflammation at 2 years were associated with any of the patient-reported outcomes at 5 years. With each log10 unit higher of serum tumor necrosis factor concentration the knee-related quality of life of KOOS was increased (i.e., better outcome) by 35 (95% confidence interval 7 to 63) points. No other serum biomarker measured at 2 years was associated with patient-reported outcome at 5 years.

CONCLUSION

Local joint inflammation assessed by biomarkers in synovial fluid and Hoffa- and effusion-synovitis on MRI at 2 years after an ACL injury did not associate with patient-reported outcomes at 5 years. Thus, chronic inflammation in the ACL-injured knee, as reflected by the biomarkers studied here, seems not to be a key determinant for the long-term patient-reported outcomes.

Inappropriate opioid dispensing in patients with knee and hip osteoarthritis: a population-based cohort study

OBJECTIVE

To estimate inappropriate opioid dispensing in patients with knee or hip osteoarthritis (OA) defined as (1) dispensing of opioids within the first year of diagnosis or (2) long-term opioid use.

DESIGN

Data from Skåne Healthcare Register was linked with the Swedish Prescribed Drug Register. Incidence proportion of dispensed opioids within first year of incident knee or hip OA diagnosis was determined in knee (n = 399,670) and hip (413,216) OA cohorts without a history of OA. The 1-year period prevalence of long-term opioid dispensing was determined in a prevalence cohort (n = 48,574 with knee and/or hip OA and n = 457,587 without OA). The proportion of OA patients with excess opioid dispensing attributable to OA was estimated using inverse probability weighted regression adjustment.

RESULTS

In the incident cohorts, 5866 and 2359 developed knee and hip OA, respectively. Within the first year after OA diagnosis 14.7% patients with knee OA and 20.7% with hip OA had an opioid dispensed. The estimated inappropriate dispensing attributable to OA was 7.4% (95% CI 6.5-8.4) for knee OA and 12.8% (95% CI 11.1-14.4) for hip OA. Among persons with prevalent knee, hip or knee and hip OA inappropriate, long-term opioid use attributable to OA was 1.3%, 2.0% and 2.4% of, respectively.

CONCLUSIONS

More than half the incident opioid dispensations to patients within their first year after knee or hip OA diagnosis are inappropriate according to current treatment guidelines. Furthermore, 2% of patients with prevalent knee or hip OA have inappropriate long-term dispensing of opioids.

The effects of weight loss on imaging outcomes in osteoarthritis of the hip or knee in people who are overweight or obese: a systematic review

OBJECTIVE

To evaluate the structural effects of weight loss on hip or knee osteoarthritis (OA) and to summarize which structural joint pathologies have been examined and the evidence for the outcome measurement instruments applied.

DESIGN

Based on a pre-specified protocol (available: PROSPERO CRD42017065263), we conducted a systematic search of the bibliographic databases, Medline, Embase and Web of Science identifying longitudinal articles reporting the effects of weight loss on structural imaging outcomes in OA of the hip or knee in people who are overweight or obese.

RESULTS

From 1625 potentially eligible records, 14 articles (from 6 cohorts) were included. 2 cohorts were derived from RCTs. Evaluated pathologies were: articular cartilage (n = 7), joint space width (n = 3), bone marrow lesions (n = 5), synovitis (n = 2), effusion (n = 1), meniscus (n = 3), bone marrow density (n = 1) and infrapatellar fat pad (IPFP; n = 2). Cartilage showed conflicting results when evaluating cartilage thickness by direct thickness measurements. Compositional dGEMRIC and T2 mapping measures in early knee OA showed trends towards reduced cartilage degeneration. Joint space width on conventional radiographs showed no change. Weight loss reduced the size of the IPFP. Synovitis and effusion were not affected. Following weight loss DXA showed bone loss at the hip.

CONCLUSION

We did not find consistent evidence of the effects of weight loss on OA structural pathology in people who are overweight or obese. There is a need to achieve consensus on which structural pathologies and measurements to apply in weight loss and OA research.

Opioid use in knee or hip osteoarthritis: a region-wide population-based cohort study

OBJECTIVE

To quantify opioid use in knee and hip osteoarthritis (OA) patients, and to estimate the proportion of opioids in the population attributable to OA patients.

DESIGN

Population-based cohort study.

METHODS

We included 751,579 residents in southern Sweden, aged ≥35 years in 2015. Doctor-diagnosed knee or hip OA between 1998 and 2015 was the exposure. Dispensed weak and strong opioids were identified between November 2013 and October 2015 from the Swedish Prescribed Drug Register (SPDR). We determined age- and sex-standardized 12-month period prevalence of opioid use from November 2014 until October 2015 and calculated prevalence ratios and incidence rate ratios adjusted for age, sex, and other socio-demographic variables. We estimated the population attributable fraction (PAF) of incident opioid use attributable to OA patients.

RESULTS

The 12-month prevalence of opioid use among OA patients was 23.7% [95% confidence intervals (CI) 23.3-24.2], which was two-fold higher compared to individuals without knee or hip OA: prevalence ratio: 2.1 [95% CI 2.1-2.1]. Similarly, OA patients were more likely to have an incident opioid dispensation, especially for strong opioids (incidence rate ratio: 2.6 [95% CI 2.5-2.7]). Population attributable tractions (PAF) of incident opioid use attributable to OA patients was 12%, 9% for weak and 17% for strong opioids.

CONCLUSIONS

Every fourth patient with knee or hip OA has opioids dispensed over a 1-year period, and 12% of incident opioid dispensations are attributable to OA and/or its related comorbidities. These results highlight that patients with knee and hip OA constitute a group of patients with an alarmingly high use of opioids.

Cause-specific mortality in osteoarthritis of peripheral joints

PURPOSE

To estimate cause-specific mortality in osteoarthritis patients compared to the general population.

METHODS

We identified all residents in southern Sweden aged 45-84 years in 2003. Through the Skåne Healthcare Register (SHR) we identified those diagnosed with osteoarthritis in peripheral joints between 1998 and 2003. We followed all residents from 2004 until relocation outside of the region, death, or end of 2014. We classified the underlying cause of death from death certificates into: cardiovascular and neoplasms, diabetes, infections, dementia, diseases of digestive system, or other causes. For estimation, we used multi-state adjusted Cox proportional hazards models.

RESULTS

We identified 15,901 patients (mean age [SD] 67 years [10], 41% men) with prevalent doctor-diagnosed osteoarthritis in knee, 9347 in hip, 4004 in hand and 5447 in other peripheral joints among 469,177 residents. For most causes of death in osteoarthritis patients, we found no increased mortality, with hazard ratios (HRs) close to 1, similar for men and women. However, for knee and hip osteoarthritis and cardiovascular death, HRs were non proportional and increased to 1.19 (95%CI 1.10, 1.28) and 1.13 (1.03, 1.24) during 9-11 years of follow-up, mostly due to excess mortality from chronic ischemic heart diseases and heart failure.

CONCLUSIONS

The risk of cardiovascular excess deaths increases with duration of knee and hip osteoarthritis. The major contributors are chronic ischemic heart diseases and heart failure. Our results call for improved implementation of osteoarthritis treatment guidelines, with major focus on interventions to address mobility limitations and maintaining or increase physical activity level.

Scrutinizing the cut-off for "pathological" meniscal body extrusion on knee MRI

OBJECTIVES

Medial meniscal body extrusion ≥ 3 mm on MRI is often considered "pathologic." The aims of this study were to (1) assess the adequacy of 3 mm as cut-off for "pathological" extrusion and (2) find an optimal cut-off for meniscal extrusion cross-sectionally associated with radiographic knee osteoarthritis, bone marrow lesions (BMLs), and cartilage damage.

METHODS

Nine hundred fifty-eight persons, aged 50-90 years from Framingham, MA, USA, had readable 1.5 T MRI scans of the right knee for meniscal body extrusion (measured in mm). BMLs and cartilage damage were read using the whole organ magnetic resonance imaging score (WORMS). Knee X-rays were read according to the Kellgren and Lawrence (KL) scale. We evaluated the performance of the 3-mm cut-off with respect to the three outcomes and estimated a new cut-off maximizing the sum of sensitivity and specificity.

RESULTS

The study persons had mean age of 62.2 years, 57.0% were women and the mean body mass index was 28.5 kg/m2. Knees with radiographic osteoarthritis, BMLs, and cartilage damage had overall more meniscal extrusion than knees without. The 3-mm cut-off had moderate sensitivity and low specificity for all three outcomes (sensitivity between 0.68 [95% CI 0.63-0.73] and 0.81 [0.73-0.87], specificity between 0.49 [0.45-0.52] and 0.54 [0.49-0.58]). Using 4 mm maximized the sum of sensitivity and specificity and improved the percentage of correctly classified subjects (from between 54 and 61% to between 64 and 79%).

CONCLUSIONS

The 4-mm cut-off may be used as an alternative cut-off for denoting pathological meniscal extrusion.

KEY POINTS

• Medial meniscal body extrusion is strongly associated with osteoarthritis. • The 3-mm cut-off for medial meniscal body extrusion has high sensitivity but low specificity with respect to bone marrow lesions, cartilage damage, and radiographic osteoarthritis. • The 4-mm cut-off maximizes the sensitivity and specificity with respect to all three osteoarthritis features.

Nature vs nurture in knee osteoarthritis - the importance of age, sex and body mass index

OBJECTIVE

(1) To estimate the life-time genetic contribution for knee osteoarthritis (OA) surgery and (2) to explore any differences in the genetic contribution across age, sex and body mass index (BMI).

METHODS

We studied the sex-specific genetic contribution to knee OA surgery in a prospective cohort study of 62,490 twins aged 35 years or older with a follow-up period of up to 47 years (10,092 identical and 21,153 non-identical twin pairs, 54% women). To study interactions with age, we graphed the heritabilities over the lifespan for men and women. We also studied the sex-specific heritability across strata of the median BMI to explore any interactions with BMI.

RESULTS

The overall heritability of knee OA surgery was 0.53 (95% confidence intervals [CI] = 0.31-0.75), with higher heritability among women (H² = 0.80 (95% CI = 0.73-0.87)) than men (H² = 0.39 (95% CI = 0.10-0.69)). For men, the heritability started to rise after age 68. The genetic contribution was particularly low in men above median BMI (H²_{≥23.7 kg/m2} = 0.08, 95% CI = -0.32-0.48). For women, the heritability was consistently high from age 50 to death, independently of BMI (H²_{≥22.5 kg/m2} = 0.77, 95% CI = 0.66-0.87).

CONCLUSION

There is a higher and more consistent genetic contribution for knee OA surgery in women than men. In men the genetic contribution was relatively low and varied with age and BMI.

Ultra-high field magnetic resonance imaging parameter mapping in the posterior horn of ex vivo human menisci

OBJECTIVE

To investigate the relationship between meniscus magnetic resonance (MR) relaxation parameters and meniscus degradation through quantitative imaging of ex vivo posterior horns of menisci from subjects with and without knee osteoarthritis (OA).

DESIGN

We sampled medial and lateral menisci from ten medial compartment knee OA patients (mean age 63 years) undergoing total knee replacement and from ten deceased donors (references, mean age 51 years). MR relaxation parameters T2*, T2 and T1 of the posterior horn were measured at a 9.4 T scanner. Comparisons were made between OA patients and references (with adjustment for age) as well as between medial and lateral menisci from the same knees.

RESULTS

Mean values (standard deviation) of mean T2* were 13 (3.8), 6.9 (2.3), 7.2 (1.9) and 7.2 (1.7) ms for the medial and lateral patient menisci and the medial and lateral reference menisci, respectively. Corresponding values were 17 (3.7), 9.0 (2.2), 12 (4) and 9.0 (1.3) ms for T2 and 1810 (150), 1630 (30), 1580 (90) and 1560 (50) ms for T1. All three relaxation times were significantly longer in medial OA menisci compared to the other groups. Among medial reference menisci, relaxation times (mainly T1) tended to increase with age.

CONCLUSIONS

MR relaxation times T2*, T2 and T1 in the posterior horn are longer in the medial menisci of patients with end-stage medial compartment knee OA compared to the corresponding lateral menisci and to reference menisci. The meniscus seems to undergo intrasubstance alterations related to both OA and ageing.

Towards prevention of post-traumatic osteoarthritis: report from an international expert working group on considerations for the design and conduct of interventional studies following acute knee injury

OBJECTIVE

There are few guidelines for clinical trials of interventions for prevention of post-traumatic osteoarthritis (PTOA), reflecting challenges in this area. An international multi-disciplinary expert group including patients was convened to generate points to consider for the design and conduct of interventional studies following acute knee injury.

DESIGN

An evidence review on acute knee injury interventional studies to prevent PTOA was presented to the group, alongside overviews of challenges in this area, including potential targets, biomarkers and imaging. Working groups considered pre-identified key areas: eligibility criteria and outcomes, biomarkers, injury definition and intervention timing including multi-modality interventions. Consensus agreement within the group on points to consider was generated and is reported here after iterative review by all contributors.

RESULTS

The evidence review identified 37 studies. Study duration and outcomes varied widely and 70% examined surgical interventions. Considerations were grouped into three areas: justification of inclusion criteria including the classification of injury and participant age (as people over 35 may have pre-existing OA); careful consideration in the selection and timing of outcomes or biomarkers; definition of the intervention(s)/comparator(s) and the appropriate time-window for intervention (considerations may be particular to intervention type). Areas for further research included demonstrating the utility of patient-reported outcomes, biomarkers and imaging outcomes from ancillary/cohort studies in this area, and development of surrogate clinical trial endpoints that shorten the duration of clinical trials and are acceptable to regulatory agencies.

CONCLUSIONS

These considerations represent the first international consensus on the conduct of interventional studies following acute knee joint trauma.

A naturally aging knee, or development of early knee osteoarthritis?

AIM

To study the development of early knee osteoarthritis (OA) in subjects with and without risk factors for knee OA.

METHODS

We studied 340 subjects from the Osteoarthritis Initiative (OAI), aged 45-55 years (51% women), free of radiographic knee OA at baseline (n = 294 with and n = 46 without knee pain and other OA risk factors). At baseline, 24, 48, 72 and 96 months we compared the two groups for prevalence and overlap of knee OA as defined by magnetic resonance imaging (MRI-based OA), x-rays (Kellgren-Lawrence grade [KLG] ≥ 1), and pain, using a logistic mixed model. We studied the group differences (%) over time by subtracting the OA prevalence of those without risk factors from the group with risk factors.

RESULTS

The group with OA risk factors had higher proportions of MRI-based OA than the group without OA risk factors at all visits, but the difference diminished at 72 months (72 months difference = 11.9%, 95% confidence intervals [CI] = -2.3-26.1). Further, at 72 months, the presence of KLG ≥ 1 were similar in the two groups (-3.5%, 95% CI = -15.2-8.2). The proportion fulfilling all three OA definitions was 1.7% at 24 months and 4.8% at 72 months of those with OA risk factors and 0% and 2.2%, respectively, in those without.

CONCLUSION

Structural changes of the knee are common irrespective of the presence of pain or other OA risk factors. Such structural changes in absence of knee symptoms should probably be considered as risk factors for early OA rather than disease.

Change in patient-reported outcomes in patients with and without mechanical symptoms undergoing arthroscopic meniscal surgery: A prospective cohort study

OBJECTIVE

Patients with degenerative or traumatic meniscal tears are at high risk of developing knee osteoarthritis. We investigated if younger (≤40 years) and older (>40 years) patients with preoperative mechanical symptoms (MS) improved more in patient-reported outcomes after meniscal surgery than those without MS.

DESIGN

Patients from Knee Arthroscopy Cohort Southern Denmark (KACS) undergoing arthroscopic surgery for a meniscal tear completed online questionnaires before surgery, and at 12 and 52 weeks follow-up. Questionnaires included self-reported presence of MS (i.e., sensation of catching and/or locking) and the Knee injury and Osteoarthritis Outcome Score (KOOS). We analyzed between-group differences in change in KOOS₄ from baseline to 52 weeks, using an adjusted mixed linear model.

RESULTS

150 younger patients (mean age 31 (SD 7), 67% men) and 491 older patients (mean age 54 (SD 9), 53% men) constituted the baseline cohorts. Patients with MS generally had worse self-reported outcomes before surgery. At 52 weeks follow-up, younger patients with preoperative MS had improved more in KOOS₄ scores than younger patients without preoperative MS (adjusted mean difference 10.5, 95% CI: 4.3, 16.6), but did not exceed the absolute postoperative KOOS₄ scores observed for those without MS. No difference in improvement was observed between older patients with or without MS (adjusted mean difference 0.7, 95% CI: -2.6, 3.9).

CONCLUSIONS

Younger patients (≤40 years) with preoperative MS experienced greater improvements after arthroscopic surgery compared to younger patients without MS. Our observational study result needs to be confirmed in randomized trials.

Trabecular bone texture detected by plain radiography is associated with MRI-defined osteophytes in finger joints of women without radiographic osteoarthritis

OBJECTIVE

To examine associations between trabecular bone (TB) texture and magnetic resonance imaging (MRI)-defined osteophytes in finger joints without radiographic osteoarthritis (OA) using an augmented variance orientation transform (AVOT) method.

DESIGN

In a cross-sectional study, associations of the TB texture and osteophytes were examined in 21 women with mean (standard deviation) age of 69.9 (5.3) from the Oslo Hand OA cohort. The AVOT was applied to distal and proximal TB regions selected on hand radiographs of the subjects. The regions were adjacent to 57 finger joints (24 distal and 33 proximal interphalangeal) without radiographic OA (Kellgren-Lawrence [KL] grade 0), without MRI-defined joint space narrowing (JSN), bone marrow lesions (BMLs), attrition, erosion, cysts, sclerosis, malalignment (all MRI grades 0) and without or only with mild synovitis (MRI grade 0 or 1). Bone texture parameters were calculated: mean fractal dimension (FD_MEAN), FDs in the horizontal (FD_H) and vertical (FD_V) directions, and along the roughest part (FD_Sta). Associations between the parameters categorized into groups using tertiles and osteophytes were evaluated using logistic regression adjusted for age.

RESULTS

Lower FD_Sta and FD_V in the distal TB regions were associated with increased odds of MRI-defined osteophytes (P < 0.037 for linear trend). No statistically significant associations were found for the proximal regions.

CONCLUSIONS

Lower mean roughness and lower roughness in vertical and roughest directions of the proximal TB texture are associated with MRI-defined osteophytes in finger joints without radiographic OA. These findings suggest that TB texture may be a useful marker for detecting early hand OA.

Epidemiology of primary systemic vasculitis in children: a population-based study from southern Sweden

OBJECTIVES

To estimate the annual incidence rate of paediatric primary systemic vasculitis (PSV) in a defined geographical area in southern Sweden.

METHODS

Potential cases of PSV [IgA vasculitis (IgAV, Henoch-Schönlein purpura), Kawasaki disease (KD), granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), eosinophilic granulomatosis with polyangiitis (EGPA), polyarteritis nodosa (PAN), and Takayasu's arteritis (TAK)] were identified in a comprehensive regional healthcare register. The study area is Skåne, the southernmost county of Sweden (population 1.29 million; 21.4% aged <18 years). Case records for children (0-17 years) assigned a diagnosis code between M300 and M319 and/or D690 were reviewed to ascertain diagnosis. Only patients diagnosed between 2004 and 2014 were included.

RESULTS

In total, 556 patients with PSV were identified. The annual incidence rate per million children (95% confidence interval) was estimated to be 200 (183-217) for all PSV, 175.5 for IgAV (160-191), 20.1 for KD (14.9-25.4), 1.4 (0-2.8) for each of GPA and MPA, 0.7 (0-1.7) for PAN, and 0.4 (0-1.1) for each of EGPA and TAK. Among children aged <10 years, 99.5% of cases were either IgAV or KD, both exhibiting a seasonal pattern paralleling infections. There were no deaths, but three cases of end-stage renal disease were noted, all in MPA.

CONCLUSIONS

Vasculitis is relatively common during childhood. Mild cases associated with the infection season are most common in the youngest age groups, while during adolescence a substantial proportion has more severe forms of vasculitis.

The risk of symptomatic knee osteoarthritis after arthroscopic meniscus repair vs partial meniscectomy vs the general population

OBJECTIVE

To compare consultation rate for knee osteoarthritis (OA) after meniscus repair, arthroscopic partial meniscectomy (APM), and in general population, respectively.

METHOD

We identified patients aged 16-45 years having had meniscus surgery due to traumatic meniscus tear in 1998-2010 in southern Sweden by a healthcare register. Patients were followed from surgery until a diagnosis of knee OA, relocation, death, or December 31st, 2015. We studied the consultation rate for knee OA compared to the general population.

RESULTS

We identified 2,487 patients diagnosed with traumatic meniscus tear (mean [SD] age 30.5 [8.6] years); 229 (9.2%) of them had had meniscus repair. The absolute risk of having consulted for knee OA during the study was 17% after APM, 10.0% after meniscus repair, and 2.3% in the general population. Hazard ratio (HR) (95% confidence interval (CI)) for knee OA after repair vs APM was: 0.74 (0.48, 1.15). Excluding cases with OA within 2 years post-surgery, yielded the HR of 0.51 (0.27, 0.96). The consultation rate for knee OA standardized to the general population was then 42 per 10,000 person-years (95% CI 12, 71) in the meniscus repair group, 118 per 10,000 person-years (95% CI 101, 135) after APM, and 20 per 10,000 person-years (95% CI 19.9, 20.1) in the general population.

CONCLUSION

The point estimates suggests about 25-50% lower risk of consultation for knee OA after meniscus repair as compared to APM. However, the consultation rate for knee OA after repair was still at least two times higher as compared to the general population.

Burden of gout in the Nordic region, 1990-2015: findings from the Global Burden of Disease Study 2015

OBJECTIVE

To explore the burden of gout in the Nordic region, with a population around 27 million in 2015 distributed across six countries.

METHOD

We used the findings of the 2015 Global Burden of Diseases study to report prevalence and disability associated with gout in the Nordic region.

RESULTS

From 1990 to 2015, the number of prevalent gout cases rose by 30% to 252 967 [95% uncertainty interval (UI) 223 478‒287 288] in the Nordic region. In 2015, gout contributed to 7982 (95% UI 5431‒10 800) years lived with disability (YLDs) in the region, an increase of 29% (95% UI 24‒35%) from 1990. While the crude YLD rate of gout increased by 12.9% (95% UI 7.8‒18.1%) between 1990 and 2015, the age-standardized YLD rate remained stable. Gout was ranked as the 63rd leading cause of total YLDs in the region in 2015, with the highest rank in men aged 55-59 years (38th leading cause of YLDs). The corresponding rank at the global level was 94. Of 195 countries studied, four Nordic countries [Greenland (2nd), Iceland (12th), Finland (14th), and Sweden (15th)] were among the top 15 countries with the highest age-standardized YLD rate of gout.

CONCLUSION

The burden of gout is rising in the Nordic region. Gout's contribution to the total burden of diseases in the region is more significant than the global average. Expected increases in gout burden owing to population growth and ageing call for stronger preventive and therapeutic strategies for gout management in Nordic countries.

Association between statin use and consultation or surgery for osteoarthritis of the hip or knee: a pooled analysis of four cohort studies

OBJECTIVE

Experimental findings and previous observational data have suggested lower risk of osteoarthritis (OA) with statin use but results are inconsistent. Large-scale studies with a clinically important outcome are needed. Thus, we aimed to determine whether statin use is associated with a reduced risk of developing clinically-defined hip or knee OA.

DESIGN

Pooled analysis based on time-to-event analysis of four population-based large cohorts, encompassing in total 132,607 persons aged 57-91 years resident in southern and central Sweden. We studied the association between statin use and time to consultation or surgery for OA of the hip or knee by time-dependent exposure analysis and Cox regression.

RESULTS

During 7.5 years of follow-up, we identified 7468 out- or inpatient treated cases of hip or knee OA. Compared with never use, current use of statins conferred no overall reduction in the risk of OA with an adjusted pooled hazard ratio (HR) of 1.04 (95% confidence intervals [95% CI] 0.99-1.10). We found no dose-response relation between duration of current statin use and the risk of OA, with similar HRs among patients with less than 1 year of use (HR 1.09; 95% CI 0.92-1.32) as in patients with use for 3 years or more (HR 1.05; 0.93-1.16). Results were comparable in those with low, medium and high dose of current statin use, without indications of heterogeneity of study results.

CONCLUSION

Statin use is not associated with reduced risk of consultation or surgery for OA of the hip or knee.

Prevalence and incidence of doctor-diagnosed Dupuytren's disease: a population-based study

The prevalence and incidence of doctor-diagnosed Dupuytren's disease in the general population is unknown. From the healthcare register for Skåne region (population 1.3 million) in southern Sweden, we identified all residents aged ⩾20 years (on 31 December 2013), who 1998 to 2013 had consulted a doctor and received the diagnosis Dupuytren's disease (International Classification of Diseases 10th Revision code M720). During the 16 years, 7207 current residents (72% men) had been diagnosed with Dupuytren's disease; the prevalence among men was 1.35% and among women 0.5%. Of all people diagnosed, 56% had received treatment (87% fasciectomy). In 2013, the incidence of first-time doctor-diagnosed Dupuytren's disease among men was 14 and among women five per 10,000. The annual incidence among men aged ⩾50 years was 27 per 10,000. Clinically important Dupuytren's disease is common in the general population.

LEVEL OF EVIDENCE

III.

Surgical Management of Degenerative Meniscus Lesions: The 2016 ESSKA Meniscus Consensus

Purpose  A degenerative meniscus lesion is a slowly developing process typically involving a horizontal cleavage in a middle-aged or older person. When the knee is symptomatic, arthroscopic partial meniscectomy has been practised for a long time with many case series reporting improved patient outcomes. Since 2002, several randomised clinical trials demonstrated no additional benefit of arthroscopic partial meniscectomy compared to non-operative treatment, sham surgery or sham arthroscopic partial meniscectomy. These results introduced controversy in the medical community and made clinical decision-making challenging in the daily clinical practice. To facilitate the clinical decision-making process, a consensus was developed. This initiative was endorsed by ESSKA.

Methods  A degenerative meniscus lesion was defined as a lesion occurring without any history of significant acute trauma in a patient older than 35 years. Congenital lesions, traumatic meniscus tears and degenerative lesions occurring in young patients, especially in athletes, were excluded. The project followed the so-called formal consensus process, involving a steering group, a rating group and a peer-review group. A total of 84 surgeons and scientists from 22 European countries were included in the process. Twenty questions, their associated answers and an algorithm based on extensive literature review and clinical expertise, were proposed. Each question and answer set was graded according to the scientific level of the corresponding literature.

Results  The main finding was that arthroscopic partial meniscectomy should not be proposed as a first line of treatment for degenerative meniscus lesions. Arthroscopic partial meniscectomy should only be considered after a proper standardised clinical and radiological evaluation and when the response to non-operative management has not been satisfactory. Magnetic resonance imaging of the knee is typically not indicated in the first-line work-up, but knee radiography should be used as an imaging tool to support a diagnosis of osteoarthritis or to detect certain rare pathologies, such as tumours or fractures of the knee.

Discussion  The present work offers a clear framework for the management of degenerative meniscus lesions, with the aim to balance information extracted from the scientific evidence and clinical expertise. Because of biases and weaknesses of the current literature and lack of definition of important criteria such as mechanical symptoms, it cannot be considered as an exact treatment algorithm. It summarises the results of the “ESSKA Meniscus Consensus Project” ( http://www.esska.org/education/projects ) and is the first official European consensus on this topic. The consensus may be updated and refined as more high-quality evidence emerges.

Level of Evidence  I.

Concentrations of synovial fluid biomarkers and the prediction of knee osteoarthritis 16 years after anterior cruciate ligament injury

OBJECTIVE

To describe the longitudinal patterns of release, and investigate the association between a set of synovial fluid biomarkers at the acute and chronic stage and the development of radiographic knee osteoarthritis (OA) after an anterior cruciate ligament (ACL) injury.

DESIGN

Synovial fluid was aspirated from the acutely ACL-injured knee within the first 2weeks (acute samples), and yearly (chronic samples) up to 7.5 years after injury in 88 subjects (60% men). Non-injured subjects (n = 12) were used as reference group. Aggrecan, cartilage oligomeric matrix protein (COMP), matrix metalloproteinase (MMP)-3 and tissue inhibitor of metalloproteinase (TIMP)-1 in synovial fluid were quantified by immunoassays. The presence of radiographic tibiofemoral (TF) or patellofemoral (PF) OA [Kellgren and Lawrence (K&L) ≥2] was examined with weight-bearing knee radiography 16 years after the ACL injury.

RESULTS

The average acute and chronic SF concentrations of COMP and aggrecan were elevated in comparison with the reference group (P < 0.001). The levels of COMP and aggrecan clearly decreased approximately half a year after the ACL injury, and returned to reference values during the 7.5 years of follow-up. Using logistic regression analysis neither acute nor chronic concentrations of the four biomarkers were associated with the development of radiographic knee OA at the 16 year follow-up.

CONCLUSION

Increased synovial fluid concentrations of aggrecan and COMP was related to knee injury, but acute and chronic synovial fluid concentrations of aggrecan, COMP, MMP-3 and TIMP-1 failed to predict knee OA 16 years after ACL injury.

Predictors of work disability after start of anti-TNF therapy in a national cohort of Swedish patients with rheumatoid arthritis: does early anti-TNF therapy bring patients back to work?

OBJECTIVES

To examine predictors of work ability gain and loss after anti-tumour necrosis factor (TNF) start, respectively, in working-age patients with rheumatoid arthritis (RA) with a special focus on disease duration.

METHODS

Patients with RA, aged 19-62 years, starting their first TNF inhibitor 2006-2009 with full work ability (0 sick leave/disability pension days during 3 months before bio-start; n=1048) or no work ability (90 days; n=753) were identified in the Swedish biologics register (Anti-Rheumatic Treatment In Sweden, ARTIS) and sick leave/disability pension days retrieved from the Social Insurance Agency. Outcome was defined as work ability gain ≥50% for patients without work ability at bio-start and work ability loss ≥50% for patients with full work ability, and survival analyses conducted. Baseline predictors including disease duration, age, sex, education level, employment, Health Assessment Questionnaire, Disease Activity Score 28 and relevant comorbidities were estimated using Cox regression.

RESULTS

During 3 years after anti-TNF start, the probability of regaining work ability for totally work-disabled patients was 35% for those with disease duration <5 years and 14% for disease duration ≥5 years (adjusted HR 2.1 (95% CI 1.4 to 3.2)). For patients with full work ability at bio-start, disease duration did not predict work ability loss. Baseline disability pension was also a strong predictor of work ability gain after treatment start.

CONCLUSIONS

A substantial proportion of work-disabled patients with RA who start anti-TNF therapy regain work ability. Those initiating treatment within 5 years of symptom onset have a more than doubled 3-year probability of regaining work ability compared with later treatment starts. This effect seems largely due to the impact of disease duration on disability pension status.

Surgical management of degenerative meniscus lesions: the 2016 ESSKA meniscus consensus

PURPOSE

A degenerative meniscus lesion is a slowly developing process typically involving a horizontal cleavage in a middle-aged or older person. When the knee is symptomatic, arthroscopic partial meniscectomy has been practised for a long time with many case series reporting improved patient outcomes. Since 2002, several randomised clinical trials demonstrated no additional benefit of arthroscopic partial meniscectomy compared to non-operative treatment, sham surgery or sham arthroscopic partial meniscectomy. These results introduced controversy in the medical community and made clinical decision-making challenging in the daily clinical practice. To facilitate the clinical decision-making process, a consensus was developed. This initiative was endorsed by ESSKA.

METHODS

A degenerative meniscus lesion was defined as a lesion occurring without any history of significant acute trauma in a patient older than 35 years. Congenital lesions, traumatic meniscus tears and degenerative lesions occurring in young patients, especially in athletes, were excluded. The project followed the so-called formal consensus process, involving a steering group, a rating group and a peer-review group. A total of 84 surgeons and scientists from 22 European countries were included in the process. Twenty questions, their associated answers and an algorithm based on extensive literature review and clinical expertise, were proposed. Each question and answer set was graded according to the scientific level of the corresponding literature.

RESULTS

The main finding was that arthroscopic partial meniscectomy should not be proposed as a first line of treatment for degenerative meniscus lesions. Arthroscopic partial meniscectomy should only be considered after a proper standardised clinical and radiological evaluation and when the response to non-operative management has not been satisfactory. Magnetic resonance imaging of the knee is typically not indicated in the first-line work-up, but knee radiography should be used as an imaging tool to support a diagnosis of osteoarthritis or to detect certain rare pathologies, such as tumours or fractures of the knee.

DISCUSSION

The present work offers a clear framework for the management of degenerative meniscus lesions, with the aim to balance information extracted from the scientific evidence and clinical expertise. Because of biases and weaknesses of the current literature and lack of definition of important criteria such as mechanical symptoms, it cannot be considered as an exact treatment algorithm. It summarises the results of the "ESSKA Meniscus Consensus Project" ( http://www.esska.org/education/projects ) and is the first official European consensus on this topic. The consensus may be updated and refined as more high-quality evidence emerges.

LEVEL OF EVIDENCE

I.