Valgus Slipped Capital Femoral Epiphysis Associated With Osteosclerotic Dysplasia Due to Hyperphosphatemic Tumoral Calcinosis

CASE: A 13-year-old boy presented with a painful limp for 2 weeks without trauma and guarded (L) hip movements with spasm. Radiographs revealed a valgus slipped capital femoral epiphysis (SCFE) of the left hip with generalized osteosclerosis. Elevated serum calcium, phosphate, and parathyroid hormone levels were noted. Whole-exome sequencing identified a homozygous FGF23 variant, confirming hyperphosphatemic tumoral calcinosis. He was managed with phosphate binders, dietary restriction, and in situ fixation of both hips. At the 2-year follow-up, alignment and function were normal. CONCLUSION: Association of valgus SCFE with metabolic or sclerosing bone dysplasia requires careful assessment to achieve favorable outcomes.