Risk Factors for Developing Perthes Disease: A Comprehensive National Analysis Spanning 2 Decades.

Abstract

Background: Perthes disease is an uncommon pediatric condition affecting the hip joint, causing varying degrees of femoral head necrosis. The underlying cause of Perthes remains unknown, thus it is crucial to identify risk factors associated with its development to aid in early diagnosis and intervention. This study aimed to analyze risk factors associated with Perthes in a large cohort.

Methods: A case-control study was conducted using data from a U.S. national database from 2003 to 2023. Patients diagnosed with Perthes were compared with those without the disease. Variables potentially associated with Perthes were analyzed using multivariable logit models, and adjusted odds ratios (AOR) with 95% CI were calculated. Statistical significance was determined, and a P-value <0.05 was considered significant.

Results: The study included 4034 patients with Perthes and 3,483,745 age-matched controls. The mean age of patients with Perthes was 8.38 years, compared with 8.35 years in the control group (P=0.27). Significant risk factors identified included male sex (AOR: 3.14, P<0.001), white race (AOR: 2.16, P<0.001), and obesity (AOR: 2.21, P<0.001). Conversely, Black (AOR: 0.26, P<0.001), Hispanic (AOR: 0.53, P<0.001), and Asian (AOR: 0.55, P<0.001) races were associated with lower odds of developing Perthes. Additional significant risk factors included tobacco exposure (AOR: 1.25, P=0.02), hypertension (AOR: 1.64, P<0.001), and thrombophilia (AOR: 9.17, P<0.001).

Conclusions: This study is the largest study on Perthes disease in literature, identifying several independent risk factors, including male sex, white race, obesity, tobacco exposure, hypertension, obesity, and thrombophilia. Among children with Perthes, thrombophilia exhibited the highest adjusted odds ratio, despite its rarity. These findings offer valuable insights for further research aimed at elucidating the underlying etiology of Perthes disease, particularly with regards to the roles of vascular and metabolic pathways.

Level of evidence: Level III-prognostic case-control study.