Risk Of Radiographic Osteoarthritis Research Articles

Bone shape mediates the relationship between sex and incident knee osteoarthritis

BackgroundKnee bone shape differs between men and women and the incidence of knee osteoarthritis (OA) is higher in women than in men. Therefore, the purpose of the present study was to determine whether the observed difference in the incidence of knee radiographic OA (ROA) between men and women is mediated by bone shape.MethodsWe randomly sampled 304 knees from the OAI with incident ROA (i.e., development of Kellgren/Lawrence grade ≥ 2 by month 48) and 304 knees without incident ROA. We characterized distal femur and proximal tibia shape on baseline radiographs using Statistical Shape Modeling. If a specific bone shape was associated with the risk of incident ROA, marginal structural models were generated to assess the mediation effect of that bone shape on the relation of sex and risk of incident knee ROA adjusting for baseline covariates.ResultsCase and control participants were similar by age, sex and race, but case knees were from higher body mass index (BMI) participants (29.4 vs. 27.0; p < 0.001). Women had 49% increased odds of incident knee ROA compared with men (adjusted odds ratio (OR) = 1.49, 95% Confidence Interval (C.I.): 1.04, 2.12). There was an inconsistent mediation effect for tibial mode 2 between sex and incident knee ROA, with an indirect effect OR of 0.96 (95% C.I.: 0.91–1.00) and a direct effect OR of 1.56 (95% C.I.: 1.08–2.27), suggesting a protective effect for this mode. Similar findings were also observed for the mediation effect of tibia mode 10 and femur mode 4. These shape modes primarily involved differences in the angular relation of the heads to the shafts of the femur and tibia.ConclusionsDistal femur and proximal tibia bone shapes partially and inconsistently mediated the relationship between sex and incident knee OA. Women had a higher risk of incident ROA, and specific bone shapes modestly protected them from even higher risk of ROA. The clinical significance of these findings warrant further investigation.

Increased risk for radiographic osteoarthritis features in young active athletes: a cross-sectional matched case–control study

Prevalence data on radiographic osteoarthritis (ROA) in young active athletes is sparse. Aim was to assess in a matched case-control design the frequency of ROA in an athlete population and whether athlete status, gender, previous anterior cruciate ligament (ACL) surgery and age increase the odds for ROA. 135 consecutive athletes (82% soccer players) 18-36 years old and 550 non-athletes aged-matched controls had knee radiography (Lyon-Schuss protocol) for assessment of subacute or chronic knee complaints. Patients with acute trauma or fractures were excluded. Radiographs were graded according to the Kellgren-Lawrence and OARSI grading schemes. In addition, medial and lateral intercondylar notch osteophytes were scored. We used logistic regression model to assess the association of ROA and specific radiographic OA features with athlete status, prior ACL surgery, gender and age, adjusting for each other. 19.4% of patients were 18-22 years old, 26.4% were 23-27, 22.6% were 28-32, and 31.5% were 33-36 years old. 18.7% were female and 8.8% had previous ACL surgery. 8.5% had ROA and 6.0% had evidence of JSN. The adjusted odds ratios (aOR) for ROA were 2.8 (95% confidence interval 1.4, 5.5) for athletes, 7.0 (3.5, 13.9) for previous ACL surgery and 3.3 (1.2, 9.0) for age range 32-36. Athlete status significantly increased odds for tibiofemoral osteophytes [aOR 2.9 (1.6, 5.4)] and comparably for notch osteophytes [aOR 2.3 (1.1, 4.7)]. Athlete status, higher age and previous ACL surgery increase the risk of ROA with surgery being the strongest risk factor.

OP0124 Mri-Based Long Term Predicition of Incident Radiographic Osteoarthritis

BackgroundPre-radiographic structural damage is likely to increase the risk of incident radiographic osteoarthritis (ROA). It is not known, however, which specific structural changes predict incident ROA over the long-term.ObjectivesThe aim...

Association analysis of BMD-associated SNPs with knee osteoarthritis.

Osteoarthritis (OA) risk is widely recognized to be heritable but few loci have been identified. Observational studies have identified higher systemic bone mineral density (BMD) to be associated with an increased risk of radiographic knee osteoarthritis. With this in mind, we sought to evaluate whether well-established genetic loci for variance in BMD are associated with risk for radiographic OA in the Osteoarthritis Initiative (OAI) and the Johnston County Osteoarthritis (JoCo) Project. Cases had at least one knee with definite radiographic OA, defined as the presence of definite osteophytes with or without joint space narrowing (Kellgren-Lawrence [KL] grade ≥ 2) and controls were absent for definite radiographic OA in both knees (KL grade ≤ 1 bilaterally). There were 2014 and 658 Caucasian cases, respectively, in the OAI and JoCo Studies, and 953 and 823 controls. Single nucleotide polymorphisms (SNPs) were identified for association analysis from the literature. Genotyping was carried out on Illumina 2.5M and 1M arrays in Genetic Components of Knee OA (GeCKO) and JoCo, respectively and imputation was done. Association analyses were carried out separately in each cohort with adjustments for age, body mass index (BMI), and sex, and then parameter estimates were combined across the two cohorts by meta-analysis. We identified four SNPs significantly associated with prevalent radiographic knee OA. The strongest signal (p = 0.0009; OR = 1.22; 95% CI, 1.08-1.37) maps to 12q3, which contains a gene coding for SP7. Additional loci map to 7p14.1 (TXNDC3), 11q13.2 (LRP5), and 11p14.1 (LIN7C). For all four loci the allele associated with higher BMD was associated with higher odds of OA. A BMD risk allele score was not significantly associated with OA risk. This meta-analysis demonstrates that several genomewide association studies (GWAS)-identified BMD SNPs are nominally associated with prevalent radiographic knee OA and further supports the hypothesis that BMD, or its determinants, may be a risk factor contributing to OA development. © 2014 American Society for Bone and Mineral Research.

OP0153 Subchondral Bone Marrow Lesions Predict Incident Radiographic Osteoarthritis

BackgroundRadiography is only able to depict structural joint damage at advanced stages of knee osteoarthritis. Pre-radiographic structural damage is likely to increase the risk of incident radiographic OA (ROA). Subchondral...

SAT0493 Medial Meniscal Damage and Extrusion Increase Risk of Incident Radiographic Osteoarthritis

BackgroundRadiography is only able to depict structural joint damage at advanced stages of knee osteoarthritis (OA). Pre-radiographic structural damage to the joint is likely to increase the risk of incident...

Methodologic challenges in studying risk factors for progression of knee osteoarthritis

Knee osteoarthritis (OA) is the most common joint disorder among adults in the US and severity of knee radiographic OA (ROA) is strongly associated with knee pain1. Pain from knee OA accounts for a large proportion of limitations with common activities of daily living2, and it is also the main reason for total knee replacement3. Because of the impact of symptoms from knee OA, people with symptomatic knee OA may be more motivated to take steps to prevent disease progression than those without ROA. Thus, investigators and persons with knee OA are particularly interested in risk factors that are associated with ROA progression because such knowledge will provide insightful guidance for secondary prevention4. Over the past few decades, many observational studies have examined risk factors for the occurrence (i.e., incident) and worsening (i.e., progressive) of knee OA. Several risk factors (i.e., female gender, obesity, high bone mineral density (BMD), joint injury, repetitive occupational stress on joints, and certain sports) have been found to be strongly associated with an increased risk for incident knee ROA5, 6. In contrast, findings on risk factors for ROA progression have been inconclusive. Except for the level of serum hyaluronic acid and generalized OA, no other risk factor has been consistently associated with the risk of ROA progression7. Interestingly, some risk factors (e.g., high BMD, low vitamin C) increase the risk of incident knee ROA but are not associated with, or even decrease, the risk of ROA progression8-11. This paradoxical phenomenon is not limited to studies of ROA. Many studies have shown that overweight and obesity increase the risk of cardiovascular disease; however, a number of studies have also reported that among subjects with preexisting cardiovascular disease, those who are overweight or moderately obese have an improved survival and lower risk of major cardiovascular events compared with subjects with normal weight12. These findings have been termed the “obesity paradox”. Similarly, while low body mass index (BMI) is associated with increased incident chronic obstructive pulmonary disease13, it does not, however, increase the risk of recurrent exacerbations of the disease14. While the risk factors for incident events may be biologically different from those for secondary events, there are also compelling methodological explanations behind such discrepancies. In this paper, we provide several explanations that may underlie the discrepancy between findings for knee ROA progression and those for knee ROA incidence. To be consistent with most studies, we consider knees eligible for studies of ROA progression being those that have preexisting mild (K/L=2) or moderate (K/L=3) ROA at baseline. We discuss how study design, study implementation, and outcome measures in studies of ROA progression can potentially bias the effect estimates of risk factors of interest using causal diagrams15. We also present findings from several large prospective studies of ROA progression to facilitate our explanations wherever applicable.