What are the Demographics and Epidemiology of Legg-Calvé-Perthes Disease in a Large Southern California Integrated Health System?

BACKGROUND: Although many authors have reported the incidence of Legg-Calvé-Perthes disease (LCPD), there have been few incidence studies in the United States on large, self-contained populations such as those within an integrated health system. Understanding the epidemiology and demographics of LCPD in this setting may help clinicians identify patients at the greatest risk and aid in diagnosis and subsequent treatment. QUESTIONS/PURPOSES: In this study we sought (1) to determine the incidence and demographics of LCPD in a large cohort of children and adolescents in a Southern California integrated healthcare system, and (2) to identify any demographic or clinical factors (such as age, sex, race/ethnicity, or BMI) that are independently associated with LCPD. METHODS: A retrospective chart analysis was done on patients diagnosed with LCPD within our integrated healthcare system in patients aged 2 to 12 years over a 3-year period between 2010-2012. There were nearly 800,000 children in this cohort. Patient demographics were recorded; the incidence of LCPD was determined for the entire group and by sex, age, and race/ethnicity. Odds ratios for an association with LCPD based on age, sex, BMI and race/ethnicity were determined using logistic regression models. RESULTS: The LCPD incidence per 100,000 for all children was 2.84, with the highest incidence in 2- to 5-year-old children (3.05; 95% CI, 1.51-4.59) and the lowest in 9- to 12-year-old children (1.06; 95% CI, 0.21-1.91). Incidence varied markedly among ethnicities, with the highest incidence in whites (5.69; 95% CI, 3.13-8.24) and the lowest in Asians (0.78; 95% CI, 0.00-2.32). Data analysis revealed a 3.13-times increased odds ratio (OR) of LCPD in 2- to 5-year-old patients versus 9- to 12-year-olds (p = 0.011), and boys had a 12.44 times greater OR of LCPD than girls (p < 0.001). Data analysis showed an increased OR for LCPD (3.41; 95% CI, 1.28-9.09) in patients with extreme obesity (BMI-for-age ≥ 1.2 × 95th percentile or a BMI ≥ 35 kg/m) compared with patients with a normal BMI. CONCLUSIONS: Our study of a large integrated healthcare system in Southern California revealed an increased association of male sex and young age (2 to 5 years old) with LCPD. The overall incidence was lower overall than previously reported, although the incidence seen in white patients was similar to that in prior studies. The finding that patients with extreme obesity may have an increased association with LCPD merits further study. These findings may increase providers' awareness of the risk of the disease in younger patients and in extremely obese patients, and it also merits further future investigation as to whether there is a cause or effect relationship between extreme obesity and LCPD. LEVEL OF EVIDENCE: Level IV, prognostic study.

Childhood Obesity is Associated With Osteochondritis Dissecans of the Knee, Ankle, and Elbow in Children and Adolescents.

BACKGROUND: Osteochondritis dissecans (OCD) is a joint disorder of the subchondral bone and articular cartilage whose association with obesity in children is not clearly known. The purpose of this study was to assess the magnitude of the association between childhood obesity and the occurrence of OCD of the knee, ankle, and elbow in children. METHODS: A retrospective chart review of an integrated health system was performed on OCD patients aged 2 to 19 from 2007 to 2011, with over 1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. The body mass index (BMI) for each patient in the cohort was used to stratify patients into 5 weight classes (underweight, normal weight, overweight, moderately obese, and extremely obese) based on BMI-for-age. The associations between the 5 weight classes and OCD of the ankle, knee, and elbow were assessed using multiple logistic regression models to estimate odds ratios (OR) and 95% confidence intervals using multivariate analysis to adjust for patient demographic variables. RESULTS: In total, 269 patients fit the inclusion criteria. Mean BMI, both absolute and percentile, was significantly higher for patients with OCD of the knee, elbow, and ankle than patients without OCD. In the multivariate analysis, extremely obese patients were found to have an increased OR of OCD for all patients, with an 86% increased risk of any OCD compared with normal weight patients. In addition, assessment by different types of OCD revealed that extremely obese patients had an increased OR of OCD of the elbow and ankle individually, with a 3.1 times increased OCD elbow risk and 3.0 times increased risk of ankle OCD in extremely obese patients. Although extremely obese patients did not have a statistically significant increased risk of knee OCD, moderately obese patients did have a 1.8 times increased risk of knee OCD as compared with normal weight children. There were no significantly different risks of any type of OCD seen in overweight or underweight patients as compared with normal weight patients. CONCLUSIONS: In this population-based cohort study, extreme obesity is strongly associated with an increased risk of OCD overall and OCD of the elbow and ankle specifically. In addition, moderate obesity is associated with an increased risk of knee OCD. All types of OCD were also found to have a significantly greater average BMI when compared with patients without OCD. LEVEL OF EVIDENCE: Level IV-descriptive epidemiology study.

Incidence of Osteochondritis Dissecans in Adults.

BACKGROUND: Osteochondritis dissecans (OCD) has frequently been described in children and adolescents, but cases of OCD in adults are certainly encountered. Little has been published on the epidemiology of OCD in adult patients. PURPOSE: To assess the frequency of OCD lesions in adults and assess the risk by age, sex, and ethnicity. STUDY DESIGN: Descriptive epidemiology study. METHODS: The authors assessed all patients aged 20 to 45 years from the entire database of patients enrolled as members of Kaiser Permanente Southern California from January 2011 until December 2013. Kaiser Southern California is an integrated health care system serving a racially, ethnically, and socioeconomically diverse population of >3.5 million patients. A retrospective chart review was done on OCD during this period. Inclusion criteria included OCD of any joint. Exclusion criteria included traumatic osteochondral fractures and coexistence of intra-articular lesions other than OCD. Joint involvement/location, laterality, and all patient demographics were recorded. RESULTS: Among 122 patients, a total of 124 OCD lesions were found. The majority of lesions were in the ankle (n = 76) and knee (n = 43), with 3 foot lesions and 2 elbow lesions identified. OCD lesions were identified in 75 men (62%) and 47 women (38%). Overall incidence rates per 100,000 person-years were 3.42 for all OCD, 2.08 for ankle OCD, and 1.21 for knee OCD. The relative risk of adult OCD for men was twice that of women. The relative risk of adult OCD for white patients was 2.3 that of Asians and 1.7 that of Hispanics. Risk of knee OCD was 3.6 times higher for men than women. As compared with women, men had a higher risk for lateral femoral condyle OCD lesions versus the medial femoral condyle ( P = .05; odds ratio [OR], 5.19). CONCLUSION: This large cohort study of Southern California adults with OCD demonstrated an increased OR for men (vs women) of OCD in all joints. The majority of symptomatic lesions were present in the ankle rather than the knee, as previously found in children. White and black patients had the highest OR of OCD; men had a significantly greater OR of lateral femoral condyle knee lesions as compared with women.

Demographics and Epidemiology of Osteochondritis Dissecans of the Elbow Among Children and Adolescents.

BACKGROUND: Osteochondritis dissecans (OCD) of the elbow is a disorder of subchondral bone and articular cartilage, of which the incidence among children is not clearly known. PURPOSE: To assess the demographics and epidemiology of OCD of the elbow among children. STUDY DESIGN: Cross-sectional study; Level of evidence, 3. METHODS: A retrospective chart review of an integrated health system for the years 2007 through 2011 was performed for patients with elbow OCD aged 2 to 19 years. Lesion location, laterality, and all patient demographics were recorded. OCD incidence was determined for the group as a whole as well as by sex and age group (2-5, 6-11, 12-19 years). Patient differences based on age, sex, and ethnicity were analyzed, and multivariable logistic regression models were used to assess the risk of elbow OCD by group. RESULTS: A total of 37 patients with 40 OCD lesions fit the inclusion criteria. No lesion was found among 2- to 5-year-olds. A majority of lesions (n = 39, 97.5%) were in the capitellum, and 1 (2.5%) was in the trochlea. Twenty-five patients (67.6%) had right-sided lesions; 9 (24.3%), left-sided; and 3 (8.1%), bilateral. The incidence of elbow OCD for patients aged 6 to 19 years was 2.2 per 100,000 overall and 3.8 and 0.6 per 100,000 for males and females, respectively. The majority of OCD cases were seen in those aged 12 to 19 years, with an incidence of 3.4 per 100,000 versus 0.38 among 6- to 11-year-olds. Multivariable logistic regression analysis revealed a 21.7-times increased odds ratio of elbow OCD among patients aged 12 to 19 years versus 6 to 11 years, and males had a 6.8-times greater odds ratio of elbow OCD than females (P < .0001 for both). Based on race and ethnicity, non-Hispanic whites had the highest incidence of elbow OCD as compared with all other ethnic groups. CONCLUSION: In this population-based cohort study of pediatric elbow OCD, males had almost 7 times the risk of elbow OCD as compared with females, and 12- to 19-year-olds had nearly 22 times the risk of elbow OCD versus 6- to 11-year-olds. In keeping with many prior studies, the majority of patients had right-sided lesions.

Osteochondritis dissecans of the ankle in children and adolescents: demographics and epidemiology.

BACKGROUND: Osteochondritis dissecans (OCD) of the ankle is a disorder of the talar or distal tibial subchondral bone and articular cartilage whose incidence in children is not clearly known. PURPOSE: To assess the demographics and epidemiology of OCD of the ankle in children. STUDY DESIGN: Descriptive epidemiologic study. METHODS: A retrospective chart review of an integrated health system was conducted on patients with ankle OCD aged 2 to 19 years from 2007 to 2011, with >1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. Ankle OCD incidence was determined for the group as a whole and by both sex and age group (divided into age groups of 2-5, 6-11, and 12-19 years). The risk for ankle OCD for age group, sex, and ethnicity was assessed using multivariate logistic regression models. RESULTS: A total of 85 patients fit the inclusion criteria, and 71.8% of lesions found were in the medial talus, 56.5% of lesions were right sided, and none were bilateral. No ankle OCD lesions were found in 2- to 5-year-olds. The incidence of ankle OCD in patients aged 6 to 19 years was 4.6 per 100,000 overall and 3.2 and 6.0 per 100,000 for male and female patients, respectively. Patients aged 12 to 19 years represented the vast majority of those with OCD, with an incidence of 6.8 per 100,000 compared with 1.1 per 100,000 in those 6 to 11 years of age. In those aged 6 to 11 and 12 to 19 years, female patients had a respective incidence of 1.5 and 8.9 per 100,000, whereas male patients had a respective incidence of 0.7 and 4.8 per 100,000. The overall female/male ratio of ankle OCD was 1.6:1. Multivariate logistic regression analysis revealed a 6.9 times increased risk for ankle OCD in patients aged 12 to 19 years compared with those aged 6 to 11 years (95% CI, 3.8-12.5; P < .0001), and female patients had a 1.5 times greater risk for ankle OCD than male patients (95% CI, 1.0-2.3; P = .06). On the basis of race and ethnicity, non-Hispanic whites had the highest relative risk for disease and African Americans the lowest risk. CONCLUSION: In this population-based cohort study of pediatric ankle OCD, female patients had a greater incidence of OCD and a 1.5 times greater risk for ankle OCD compared with male patients. Teenagers had nearly 7 times the risk for ankle OCD compared with children 6 to 11 years of age.

The demographics and epidemiology of osteochondritis dissecans of the knee in children and adolescents.

BACKGROUND: Osteochondritis dissecans (OCD) is a disorder of subchondral bone and articular cartilage whose incidence in children is not clearly known. PURPOSE: The purpose of this study was to assess the demographics and epidemiology of OCD of the knee in children. STUDY DESIGN: Descriptive epidemiology study. METHODS: A retrospective chart review of an integrated health system was performed on patients with OCD of the knee aged 2 to 19 years from 2007 to 2011, with over 1 million patients in this cohort. Lesion location, laterality, and all patient demographics were recorded. The incidence of OCD was determined for the group as a whole and by sex and age group (2-5 years, 6-11 years, and 12-19 years). Patient differences based on age, sex, and ethnicity were analyzed, and using multivariable logistic regression models, associations between age, sex, ethnicity, and diagnosis of OCD of the knee were evaluated. RESULTS: One hundred ninety-two patients with 206 OCD lesions of the knee fit the inclusion criteria. No OCD lesion of the knee was found in 2- to 5-year-old children. One hundred thirty-one (63.6%) lesions were in the medial femoral condyle, 67 (32.5%) were in the lateral femoral condyle, 96 (50.0%) lesions were right sided, 82 (42.7%) were left sided, and 14 (7.3%) were bilateral. The incidence of patients with OCD of the knee aged 6 to 19 years was 9.5 per 100,000 overall and 15.4 and 3.3 per 100,000 for male and female patients, respectively. Those aged 12 to 19 years represented the vast majority of OCD, with an incidence of 11.2 per 100,000 versus 6.8 per 100,000 for those aged 6 to 11 years. For those aged 6 to 11 and 12 to 19 years, female patients had an incidence of 2.3 and 3.9 per 100,000, respectively, while male patients had an incidence of 11.1 and 18.1 per 100,000, respectively. Multivariable logistic regression analysis revealed a 3.3-fold increased risk of OCD of the knee in patients aged 12 to 19 years compared with those aged 6 to 11 years (P < .001; 95% confidence interval [CI], 2.37-4.48), and male patients had 3.8 times a greater risk of OCD of the knee than female patients (P < .001; 95% CI, 2.71-5.41). Based on race and ethnicity, blacks had the highest odds ratio of OCD of the knee compared with all other ethnic groups. CONCLUSION: In this population-based cohort study of pediatric OCD of the knee, male patients had a much greater incidence of OCD and almost 4 times the risk of OCD compared with female patients. Also, patients aged 12 to 19 years had 3 times the risk of OCD of the knee as compared with 6- to 11-year-old children.

Associations between childhood obesity and upper and lower extremity injuries.

OBJECTIVES: To estimate the overall and age-specific associations between obesity and extremity musculoskeletal injuries and pain in children. METHODS: This cross-sectional study used information from electronic medical records of 913178 patients aged 2-19 years enrolled in an integrated health plan in the period 2007-2009. Children were classified as underweight, normal weight, overweight, or moderately/extremely obese and, using multivariable logistic regression methods, the associations between weight class and diagnosis of upper or lower extremity fractures, sprains, dislocations and pain were calculated. RESULTS: Overweight (OR 1.18, 95% CI 1.15 to 1.20), moderately obese (OR 1.24, 95% CI 1.20 to 1.27) and extremely obese (OR 1.34, 95% CI 1.30 to 1.39) children had statistically significantly higher odds of lower extremity injuries/pain compared to normal weight, adjusted for sex, age, race/ethnicity and insurance status. Age-stratified analyses yielded similar results. No consistent association was observed between body mass index and injuries/pain of the upper extremities. CONCLUSIONS: Greater body mass index is associated with increased odds of lower extremity injuries and pain issues. Because the benefits of physical activity may still outweigh the risk of injury, attention should be paid to injury prevention strategies for these children at greater risk for lower extremity injuries.