Kellgren & Lawrence grading in cohort studies: methodological update and implications illustrated using data from the CHECK cohort

Pincer Morphology Is Not Associated With Hip Osteoarthritis Unless Hip Pain Is Present: Follow-Up Data From a Prospective Cohort Study

OBJECTIVE

The objective of this study was to assess the relationship between pincer morphology and radiographic hip osteoarthritis (RHOA) over 2, 5, 8, and 10 years' follow-up and to study the interaction between pincer morphology and pain.

METHODS

Individuals from the prospective Cohort Hip and Cohort Knee study were drawn. Anteroposterior pelvic and false profile radiographs were obtained. Hips free of definite RHOA (Kellgren and Lawrence [KL] grade 0 or 1) at baseline were included. Pincer morphology was defined as a lateral or anterior center edge angle or both ≥40° at baseline. Incident RHOA was defined as KL ≥ 2 or total hip replacement at follow-up. Multivariable logistic regression with generalized estimating equations estimated the associations at follow-up. Associations were expressed as unadjusted odds ratios (ORs) and adjusted ORs with 95% confidence intervals (CIs). An interaction term was added to investigate whether pincer morphology had a different effect on symptomatic hips.

RESULTS

Incident RHOA developed in 69 hips (5%) at 2 years' follow-up, in 178 hips (14%) at 5 years' follow-up, in 279 hips (24%) at 8 years' follow-up, and in 495 hips (42%) at 10 years' follow-up. No significant associations were found between pincer morphology and incident RHOA (adjusted OR 0.35 [95% CI 0.06-2.15]; adjusted OR 1.50 [95% CI 0.94-2.38]). Significant interactions between pain and anterior pincer morphology in predicting incident RHOA were found at 5, 8, and 10 years' follow-up (OR 1.97 [95% CI 1.03-3.78]; OR 3.41 [95% CI 1.35-8.61]).

CONCLUSION

No associations were found between radiographic pincer morphology and incident RHOA at any follow-up moment. Anteriorly located pincer morphology with hip pain, however, was significantly associated with incident RHOA. This highlights the importance of studying symptoms and hip morphology simultaneously.

Cohort profile: Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) - an international consortium of prospective cohort studies with individual participant data on hip osteoarthritis

PURPOSE

Hip osteoarthritis (OA) is a major cause of pain and disability worldwide. Lack of effective therapies may reflect poor knowledge on its aetiology and risk factors, and result in the management of end-stage hip OA with costly joint replacement. The Worldwide Collaboration on OsteoArthritis prediCtion for the Hip (World COACH) consortium was established to pool and harmonise individual participant data from prospective cohort studies. The consortium aims to better understand determinants and risk factors for the development and progression of hip OA, to optimise and automate methods for (imaging) analysis, and to develop a personalised prediction model for hip OA.

PARTICIPANTS

World COACH aimed to include participants of prospective cohort studies with ≥200 participants, that have hip imaging data available from at least 2 time points at least 4 years apart. All individual participant data, including clinical data, imaging (data), biochemical markers, questionnaires and genetic data, were collected and pooled into a single, individual-level database.

FINDINGS TO DATE

World COACH currently consists of 9 cohorts, with 38 021 participants aged 18-80 years at baseline. Overall, 71% of the participants were women and mean baseline age was 65.3±8.6 years. Over 34 000 participants had baseline pelvic radiographs available, and over 22 000 had an additional pelvic radiograph after 8-12 years of follow-up. Even longer radiographic follow-up (15-25 years) is available for over 6000 of these participants.

FUTURE PLANS

The World COACH consortium offers unique opportunities for studies on the relationship between determinants/risk factors and the development or progression of hip OA, by using harmonised data on clinical findings, imaging, biomarkers, genetics and lifestyle. This provides a unique opportunity to develop a personalised hip OA risk prediction model and to optimise methods for imaging analysis of the hip.

Analysis of the Level of Adiponectin and Selected Cytokines in Patients with Knee Osteoarthritis

Background and Objectives: Knee osteoarthritis (KOA) is a degenerative disease that is continuously targeting people of different ages, but especially the elderly population, the number of which tends to increase continuously at the global level. Apart from age, excess weight can influence the evolution of the disease, with obesity being associated with a weak inflammation stage and an imbalance between pro-inflammatory and anti-inflammatory cytokines. The present work aimed to analyze specific biomarkers, namely ACRP-30, IL-10, TNF-α, and IL-6, in knee synovial fluid, and correlate them with KOA patients' clinical data, radiographic changes, and functional and pain scores. Materials and Methods: 24 subjects with KOA and over 50 years of age participate in the present study. Synovial fluid was harvested using ultrasound guidance from the target knees of the enrolled KOA patients, and the levels of ACRP-30, IL-10, TNF-α, and IL-6 were measured using enzyme-linked immunosorbent assays (ELISA). All patients underwent a supine X-ray at the target knee and were classified using Kellgren-Lawrence (K-L) grading. The Western Ontario and McMaster University Osteoarthritis Index (WOMAC) was used to assess self-reported physical function, pain, and stiffness. Results: The obtained results highlighted a significant correlation between age and adiponectin level (p = 0.0451, r = -0.412). Also, the IL-10 values are lower in cases where the intensity of the pain is more pronounced (p = 0.0405, r = -0.421). In addition, analyzing the data by gender, it was observed that in the case of males, stiffness is more related to age (p = 0.0079, r = 0.7993), compared to women (p = 0.0203, r = 0.6223). In the case of women, the progression of the disease tends to increase more intensively the WOMAC score's total values (p = 0.00031, r = 0.8342), compared with men (p = 0.0289, r = 7013). Regarding interleukins and BMI, significant correlations were observed only in the case of men. Conclusions: A significant correlation between age and adiponectin, and adiponectin and IL-6, suggests that advanced age may contribute to adiponectin reduction. Comparing men with women, it was observed that men's age is more related to rigidity, and IL-6 and IL-10 are directly correlated to BMI; in addition, women seem to be more sensitive to pain and stiffness.

Assessment of Generalized Joint Hypermobility and Its Association With Osteoarthritis, BMI, and Age: A Study in Southern Lahore

BACKGROUND AND OBJECTIVE

Joint hypermobility is a physiological variation in the joint range of motion that allows individuals to move their joints beyond the normal limit. Generalized joint hypermobility (GJH) refers to an increased flexibility observed throughout various joints in the body. In younger individuals, joint hypermobility is often more pronounced, serving as a double-edged sword by providing enhanced flexibility for certain activities while simultaneously increasing the susceptibility to musculoskeletal issues. Weight gain and overactivity of joints (joint hypermobility) are associated with the onset of osteoarthritis (OA), and data for the local populace is lacking. This study aims to assess GJH and OA in young and middle-aged women in southern Lahore.

METHODOLOGY

A cross-sectional study recruited 116 diagnosed OA patients through a random convenient sampling method. These patients were assessed for GJH using the Beighton criterion. For the assessment of GJH, the Beighton criterion was used, and for OA, radiographs of knee joints were taken. The Beighton criterion consists of nine movements, and each maneuver is assigned a score of either 0 or 1, resulting in a range from 0 to 9. A chi-square test was used for the group comparison of study variables.

RESULTS

A total of 116 adult females participated, with a mean age of 38.34 ± 9.761 and an age range of 20 to 55 years. GJH was assessed and correlated with age using the chi-square correlation and test. Results indicated that 78 (67.24%) exhibited hypermobility at various joint levels, with a likelihood ratio of 43.336 and a P-value of <0.001. GJH and BMI were correlated by employing Pearson chi-square correlation, with Pearson chi-square of 2.51 and P-value of 0.112 suggestive of no significant association between BMI and GJH.

CONCLUSIONS

The dynamic nature of joint hypermobility emphasizes the need to consider age-related changes when assessing its impact on musculoskeletal health. Assessment and management of hypermobility in patients of OA, especially in females, should be made part of routine practices.

Cam morphology is strongly and consistently associated with development of radiographic hip osteoarthritis throughout 4 follow-up visits within 10 years

OBJECTIVE

To determine the association between cam morphology and the development of radiographic hip osteoarthritis (RHOA) at four time points within 10-year follow-up.

DESIGN

The nationwide prospective Cohort Hip and Cohort Knee study includes 1002 participants aged 45-65 years with 2-, 5-, 8-, and 10-year follow-ups. The associations of cam morphology (alpha angle >60°) and large cam morphology (alpha angle >78°) in hips free of osteoarthritis at baseline (Kellgren & Lawrence (KL) grade <2) with the development of both incident RHOA (KL grade≥2) and end-stage RHOA (KL grade≥3) were estimated using logistic regression with generalized estimating equation at each follow-up and using Cox regression over 10 years, adjusted for age, sex, and body mass index.

RESULTS

Both cam morphology and large cam morphology were associated with the development of incident RHOA at all follow-ups with adjusted Odd Ratios (aORs) ranging from 2.7 (95% Confidence interval 1.8-4.1) to 2.9 (95% CI 2.0-4.4) for cam morphology and ranging from 2.5 (95% CI 1.5-4.3) to 4.2 (95% CI 2.2-8.3) for large cam morphology. For end-stage RHOA, cam morphology resulted in aORs ranging from 4.9 (95% CI 1.8-13.2) to 8.5 (95% CI 1.1-64.4), and aORs for large cam morphology ranged from 6.7 (95% CI 3.1-14.7) to 12.7 (95% CI 1.9-84.4).

CONCLUSIONS

Cam morphology poses the hip at 2-13 times increased odds for developing RHOA within a 10-year follow-up. The association was particularly strong for large cam morphology and end-stage RHOA, while the strength of association was consistent over time.

Osteoarthritis of the hip: is radiography still needed?

Diagnosis of hip osteoarthritis (OA) is based on clinical arguments, and medical imaging is obtained to confirm the diagnosis and rule out other possible sources of pain. Conventional radiographs are recommended as the first line imaging modality to investigate chronic hip pain. They should be obtained in a rigorous technique that includes an antero-posterior (AP) radiograph of the pelvis. The choice of the appropriate lateral view depends on the clinical indication, Lequesne's false profile being valuable in the assessment of OA. Magnetic resonance imaging (MRI) is more sensitive to detect joint effusion/synovitis, cartilage, labral, and bone marrow lesions. However, structural joint changes are frequent in asymptomatic population and neither radiographs nor MRI have shown a good correlation with pain and functional impairment. MRI seems to be more suitable than radiographs as a biomarker for clinical trials addressing early OA. The absence of a validated MR biomarker of early OA, together with issues related to machine availability and MRI protocol repeatability, prevent the widespread use of MRI in clinical trials.

Nocturnal pain and fatigue in middle-aged persons with hip symptoms suspected to be osteoarthritis, is there a link in 10-year follow-up of the CHECK study?

Objective

To explore the prevalence of nocturnal pain and fatigue in participants with hip symptoms suspected to be early osteoarthritis (OA) and to test the mediating effect of nocturnal pain on the association between hip OA pain and fatigue.

Methods

We included participants with hip pain but no knee pain at baseline, from the Cohort Hip and Cohort Knee (CHECK)-study. Severity of hip OA pain was determined using the Numeric-Rating-Scale-pain-score last week. Fatigue was assessed using the SF-36 Fatigue subscale. Nocturnal pain was determined using the WOMAC-question: "How much pain have you experienced in the last 48 ​h at night while in bed?". Hip OA pain, nocturnal pain and fatigue were measured repeatedly during 10-year follow-up. Path analysis were used per time point to determine the direct effect of OA pain on fatigue and the indirect effect through nocturnal pain.

Results

In 170 participants (female: 76%; mean age: 55.7 years; mean BMI: 25.5 ​kg/m²) the prevalence of nocturnal pain varied between 22 and 35% and the prevalence of fatigue ranged between 14 and 18%. Hip OA pain was associated with nocturnal pain and fatigue. The direct effect of hip OA pain on fatigue was significant at all-time points. No significant mediating effect of nocturnal pain was found.

Conclusion

In this cohort of participants suspected to have early hip OA, the prevalence of fatigue remained stable and the prevalence of nocturnal pain decreased slightly over 10-year follow-up. We did not find a mediating effect of nocturnal pain in the pathway between hip OA pain and fatigue.

A machine learning approach reveals features related to clinicians' diagnosis of clinically relevant knee osteoarthritis

OBJECTIVES

To identify highly ranked features related to clinicians' diagnosis of clinically relevant knee OA.

METHODS

General practitioners (GPs) and secondary care physicians (SPs) were recruited to evaluate 5-10 years follow-up clinical and radiographic data of knees from the CHECK cohort for the presence of clinically relevant OA. GPs and SPs were gathered in pairs; each pair consisted of one GP and one SP, and the paired clinicians independently evaluated the same subset of knees. A diagnosis was made for each knee by the GP and SP before and after viewing radiographic data. Nested 5-fold cross-validation enhanced random forest models were built to identify the top 10 features related to the diagnosis.

RESULTS

Seventeen clinician pairs evaluated 1106 knees with 139 clinical and 36 radiographic features. GPs diagnosed clinically relevant OA in 42% and 43% knees, before and after viewing radiographic data, respectively. SPs diagnosed in 43% and 51% knees, respectively. Models containing top 10 features had good performance for explaining clinicians' diagnosis with area under the curve ranging from 0.76-0.83. Before viewing radiographic data, quantitative symptomatic features (i.e. WOMAC scores) were the most important ones related to the diagnosis of both GPs and SPs; after viewing radiographic data, radiographic features appeared in the top lists for both, but seemed to be more important for SPs than GPs.

CONCLUSIONS

Random forest models presented good performance in explaining clinicians' diagnosis, which helped to reveal typical features of patients recognized as clinically relevant knee OA by clinicians from two different care settings.

Associations between biomarkers of matrix metabolism and inflammation with pain and fatigue in participants suspected of early hip and or knee osteoarthritis: data from the CHECK study

OBJECTIVES

To assess the associations of biomarkers in serum [highsensitivity C-reactive protein (hs-CRP), serum cartilage oligomeric protein (sCOMP), serum propeptide of type I procollagen (sPINP) and serum osteocalcin (sOC)] and urine [urinary type II collagen telopeptide (uCTX-2)] with the extent and progression of nocturnal pain, pain while walking, and fatigue in participants with hip and/or knee pain suspected to be early stage osteoarthritis (OA).

METHODS

hs-CRP, uCTX-2, sCOMP, sPINP and sOC were measured at baseline in 1,002 participants of the Cohort Hip and Cohort Knee (CHECK). Nocturnal pain, pain while walking and fatigue were assessed by self-reported questionnaires at baseline and 2-year follow-up. Associations between these biomarkers and symptoms were examined using logistic and linear regression analyses.

RESULTS

hs-CRP was significantly associated with mild nocturnal pain (OR 1.18 95% CI 1.01-1.37), with mild and moderate pain while walking (OR 1.17 95% CI 1.01-1.35 and OR 1.56 95% CI 1.29-1.90, respectively) and with progression of nocturnal pain (OR 1.25 95% CI 1.07-1.46). uCTX-2 was associated with mild nocturnal pain (OR 1.40 95% CI 1.05-1.85) and with mild and severe-extreme pain while walking (OR 1.35 95% CI 1.04-1.75 and OR 2.55 95% CI 1.03-6.34, respectively). sPINP was associated with severe-extreme nocturnal pain (OR 0.45 95% CI 0.25-0.82). No significant associations were found for sCOMP and sOC, nor for any of the biomarkers and fatigue.

CONCLUSION

This study of biomarkers in a large cohort of participants with hip and/or knee pain suspected to reflect early stage hip and/or knee OA suggests that inflammation and cartilage matrix degeneration play a role in pain, but not in fatigue.

Course of pain and fluctuations in pain related to suspected early hip osteoarthritis: the CHECK study

OBJECTIVES

To evaluate the prevalence during a 10-year follow-up of clinically relevant fluctuations in pain and the course of hip pain in participants with hip complaints suspected to be early stage hip osteoarthritis (OA). To distinguish between participants with relevant fluctuations in pain and those without based on baseline characteristics.

METHODS

Data were collected at baseline and after 2, 5, 8, and 10 years on 495 participants from the Cohort Hip and Cohort Knee Study (CHECK) with hip pain at baseline. Baseline demographic, anamnestic, and physical-examination characteristics were assessed. The primary outcome was levels of pain in the past week (scored using 0-10 Numeric Rating Scale) at follow-up assessments. Relevant fluctuation was defined as average absolute residuals greater than 1 after fitting a straight line to the participant's pain scores over time.

RESULTS

The majority of the participants (76%) had stable or decreasing pain. Relevant fluctuations were found in 37% of the participants. The following baseline variables were positively associated with the presence of relevant fluctuations: higher levels of pain in the past week, use of pain transformation as a coping style, higher number of comorbidities, use of pain medication, and higher levels of high-sensitivity C-reactive protein. No associations were found for baseline radiographic hip OA or clinical hip OA.

CONCLUSION

During a 10-year follow-up, the majority of participants had stable or decreasing pain levels. In those participants with relevant fluctuation (37%), a limited number of baseline variables were associated with increased odds of having relevant fluctuations in pain.

Association between hip pain and radiographic hip osteoarthritis in primary care: the CHECK cohort

BACKGROUND

The diagnosis of hip osteoarthritis (OA) is often based on clinical symptoms, such as pain and stiffness, and radiographic features. However, the association between hip pain and hip radiographic OA (ROA) remains uncertain.

AIM

To examine the association between hip pain and hip ROA.

DESIGN AND SETTING

Cross-sectional analysis of a Dutch cohort, the Cohort Hip and Cohort Knee (CHECK) study.

METHOD

The participants (aged 45-65 years) had all experienced hip and/or knee pain for which they had not had a prior consultation or were within 6 months of their first consultation with a GP. Using weight-bearing anteroposterior pelvis radiographs, definite and early-stage hip ROA were defined as Kellgren and Lawrence grade ≥2 and ≥1, respectively. Presence of ROA and pain was assessed in the hips of all participants. The association between hip pain and ROA was assessed using generalised estimating equations.

RESULTS

The prevalence of definite ROA was 11.0% (n = 218/1982 hips), with prevalence in painful and pain-free hips of 13.3% (n = 105/789) and 9.5% (n = 113/1193), respectively. Prevalence of early-stage hip ROA was 35.3% (n = 700/1982), with prevalence in painful and pain-free hips of 41.2% (n = 325/789) and 31.4% (n = 375/1193), respectively. Compared with pain-free hips, the odds ratio painful hips was 1.51 (95% confidence interval [CI] = 1.16 to 1.98) for definite ROA and 1.47 (95% CI = 1.24 to 1.75) for early-stage ROA.

CONCLUSION

Hip pain was associated with definite and early-stage hip ROA, yet the overall ROA prevalence was modest and the prevalence among pain-free hips was substantial. Therefore, radiographs provided little assistance with help to identify patients with hip OA among patients who recently presented with hip or knee complaints.

Higher risk of knee arthroplasty during ten-year follow-up if baseline radiographic osteoarthritis involves the patellofemoral joint: a CHECK Cohort Study

Background

Patellofemoral OA is a strong risk factor for progression to generalized whole knee OA, but it is unknown whether involvement of the patellofemoral joint in early radiographic OA (ROA) is associated with risk of undergoing future knee arthroplasty. This is clinically relevant because patellofemoral OA likely requires a different treatment approach than tibiofemoral OA, and identifying prognostic factors for future arthroplasty might assist clinicians with prioritizing and guiding early interventions that could improve long-term outcomes. Therefore, we evaluated association of baseline patellofemoral or tibiofemoral ROA with undergoing knee arthroplasty over 10 years.

Methods

Using the multicenter Cohort Hip and Cohort Knee (CHECK) study, we acquired three views of radiographs in both knees of individuals aged 45–65 years with complaints of knee symptoms in at least one knee. From baseline radiographs, we categorized each knee as having one of four patterns of ROA: no ROA, isolated patellofemoral ROA, isolated tibiofemoral ROA, or combined ROA. We evaluated the 10-year relative hazard for undergoing going arthroplasty, based on baseline ROA pattern, using Cox proportional hazard models, adjusting for age, sex body mass index, and pain severity.

Result

Our sample (n = 842) included 671 (80%) women and had mean (SD) age 56 (5) years, and BMI 26.3 (4.0) kg/m². Arthroplasties were undertaken in 44/1678 knees. In comparison to having no ROA at baseline, adjusted hazard ratios (aHR) for arthroplasty were highest for combined ROA (aHR 14.2 [95% CI 5.8, 34.6]) and isolated patellofemoral ROA (aHR 12.7 [5.6, 29.0]). Isolated tibiofemoral ROA was not significantly associated with arthroplasty (aHR 2.9 [0.6, 13.6]).

Conclusions

In a sample of middle-aged individuals with complaints in one or both knees, the 10-year relative hazard for undergoing arthroplasty, compared to no ROA, was increased when OA involved the patellofemoral joint, regardless of whether it was isolated to the patellofemoral joint or occurred in combination with tibiofemoral OA. Further research is needed to confirm this association and to clarify the causal mechanism of this relationship. However, our results provide preliminary evidence that identifying patellofemoral ROA may be a clinically useful prognostic indicator in early knee OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05549-6.

Diagnostic criteria for early hip osteoarthritis: first steps, based on the CHECK study

Objectives

Although there is a general focus on early diagnosis and treatment of hip OA, there are no validated diagnostic criteria for early-stage hip OA. The current study aimed to take the first steps in developing diagnostic criteria for early-stage hip OA, using factors obtained through history taking, physical examination, radiography and blood testing at the first consultation in individuals presenting with hip pain, suspicious for hip OA, in primary care.

Methods

Data of the 543 individuals with 735 symptomatic hips at baseline who had any follow-up data available from the prospective CHECK cohort study were used. A group of 26 clinical experts [general practitioners (GPs), rheumatologists and orthopaedic surgeons] evaluated standardized clinical assessment forms of all subjects on the presence of clinically relevant hip OA 5–10 years after baseline. Using the expert-based diagnoses as reference standard, a backward selection method was used to create predictive models based on pre-defined baseline factors from history taking, physical examination, radiography and blood testing.

Results

Prevalence of clinically relevant hip OA during follow-up was 22%. Created models contained four to eight baseline factors (mainly WOMAC pain items, painful/restricted movements and radiographic features) and obtained area under the curve between 0.62 (0.002) and 0.71 (0.002).

Conclusion

Based on clinical and radiographic features of hip OA obtained at first consultation at a GP for pain/stiffness of the hip, the prediction of clinically relevant hip OA within 5–10 years was ‘poor’ to ‘fair’.