Vitamin D Status in Blount Disease

Area of Science:

• Orthopedics
• Pediatrics
• Endocrinology

Background:

• Blount disease is idiopathic proximal tibial vara, with obesity as a known causative factor.
• Etiologies for Blount disease, including mechanical factors, have been proposed.
• This study aimed to explore a potential association between vitamin D deficiency and Blount disease.

Purpose of the Study:

• To assess the prevalence of vitamin D deficiency in children diagnosed with Blount disease.
• To determine if vitamin D deficiency plays a role in the etiology of Blount disease.

Main Methods:

• Retrospective analysis of 50 patients with Blount disease undergoing preoperative and postoperative screening.
• Exclusion of patients with genu varum secondary to rickets or confirmed vitamin D deficiency.
• Measurement of serum calcium, phosphate, alkaline phosphatase, parathyroid hormone, and 25-hydroxyvitamin D (25(OH)D) levels.

Main Results:

• The study included 50 patients with a mean age of 10.4 years and a mean BMI of 28.7 kg/m².
• Vitamin D deficiency (25(OH)D <50 nmol/L) was identified in 16% of patients.
• The prevalence of vitamin D deficiency in Blount disease patients was comparable to healthy children in the same region.

Conclusions:

• The prevalence of vitamin D deficiency in children with Blount disease is similar to that of the general pediatric population in Johannesburg.
• This study found no evidence to support vitamin D deficiency as a causative factor in Blount disease.