title: Comorbidities in Perthes' disease: a case control study using the General Practice Research database.
abstract: Perthes' disease is an osteonecrosis of the juvenile   hip, the aetiology of which is unknown. A number of comorbid associations   have been suggested that may offer insights into aetiology, yet   the strength and validity of these are unclear. This study explored   such associations through a case control study using the United   Kingdom General Practice Research database. Associations investigated   were those previously suggested within the literature. A   total of 619 cases of Perthes' disease were included, as were 2544   controls. The risk of Perthes' disease was significantly increased   with the presence of congenital anomalies of the genitourinary and   inguinal region, such as hypospadias (odds ratio (OR) 4.04 (95%   confidence interval (CI) 1.41 to 11.58)), undescended testis (OR   1.83 (95% CI 1.12 to 3.00)) and inguinal herniae (OR 1.79 (95% CI   1.02 to 3.16)). Attention deficit hyperactivity disorder was not   associated with Perthes' disease (OR 1.01 (95% CI 0.48 to 2.12)),   although a generalised behavioural disorder was (OR 1.55 (95% CI 1.10   to 2.17)). Asthma significantly increased the risk of Perthes' disease   (OR 1.44 (95% CI 1.17 to 1.76)), which remained after adjusting   for oral/parenteral steroid use. Perthes' disease has a significant association with congenital   genitourinary and inguinal anomalies, suggesting that intra-uterine   factors may be critical to causation. Other comorbid associations   may offer insight to support or refute theories of pathogenesis.
authors.affiliation: Alder Hey Children's Hospital, Orthopaedic Department, Eaton Road, Liverpool L12 2AP, UK. danperry@doctors.org.uk
authors.forename: D C
authors.initials: DC
authors.lastname: Perry
authors.forename: C E
authors.initials: CE
authors.lastname: Bruce
authors.forename: D
authors.initials: D
authors.lastname: Pope
authors.forename: P
authors.initials: P
authors.lastname: Dangerfield
authors.forename: M J
authors.initials: MJ
authors.lastname: Platt
authors.forename: A J
authors.initials: AJ
authors.lastname: Hall
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D005260:Female; D058006:General Practice; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007873:Legg-Calve-Perthes Disease / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D018570:Risk Assessment; D012307:Risk Factors; D006113:United Kingdom