Vitamin D Deficiency in Slipped Upper Femoral Epiphysis: Time to Physeal Fusion.

BACKGROUND: Slipped upper femoral epiphysis (SUFE) has an incidence of 1 to 7 per 100,000 adolescents in the United Kingdom and its link with obesity is well established. With an increasing number of pediatric orthopaedic patients presenting with vitamin D deficiency, the aim of our study was to establish the prevalence of vitamin D deficiency in SUFE patients presenting to an orthopaedic department in the United Kingdom and whether a low vitamin D level increases the time to proximal femoral physeal fusion after surgical fixation.

METHODS: A total of 27 pediatric patients, with a female to male ratio of 17:10 and a mean age of 11.5 years (SD=1.99), range 8 to 16 years, presented with a SUFE and their vitamin D level was assessed during the study period, June 2007 to July 2012 (inclusive). The majority of these patients (85.2%) were assessed as vitamin D deficient, with a serum 25-(OH)D<52 nmol/L. The time taken for >50% physeal fusion on anteroposterior radiography after surgical fixation reported in the literature is 9.6 months, with no reported vitamin D deficiency or insufficiency.

RESULTS: In our study, the median time to physeal fusion in the vitamin D-deficient and vitamin D-insufficient patients was 25 months (interquartile range, 17 to 43 mo; mean of 29 mo, SD=16.8). A negative correlation was also observed between vitamin D level and the time taken for physeal fusion after surgical fixation.

CONCLUSIONS: We conclude that a high prevalence of vitamin D deficiency has been observed in our SUFE patients. Comparing the time taken for physeal closure of 9.6 months in the literature with vitamin D-deficient patients, this is prolonged. Indeed, a negative correlation has been shown between vitamin D level and time to physeal fusion. This study highlights the need for regular vitamin D status assessment in SUFE patients to allow early implementation of treatment with vitamin D supplementation. The impact of vitamin D screening and supplementation on SUFE outcomes should be investigated further.