The seasonality of slipped upper femoral epiphysis - meta-analysis: a possible association with vitamin D.
Hip Int. 2015 May 29:0. doi: 10.5301/hipint.5000203. [Epub ahead of print]
Farrier AJ 1, Ihediwa U, Khan S, Kumar A, Gulati V, Uzoigwe CE, Choudhury MZ.
1University Hospitals of North Tees, Stockton-on-Tees - UK
We performed a meta-analysis of studies evaluating the seasonality of slipped upper femoral epiphysis (SUFE). In addition we compared the monthly incidences of SUFE at latitudes greater than 40° with the established serum 25-hydroxyvitamin levels for children resident at a comparative latitude. In total 11 relevant studies were identified, involving 7451 cases of SUFE. There was significant variation in the month of onset of SUFE. The degree of variability increased with increasing latitude. The modal month of symptomatic onset was dependent upon latitude. At latitudes greater than 40°, the most common month of onset was August. At latitudes between 20° and 40°, this was earlier in the calendar year, around April. The seasonal variability was statistically significant (p<0.0001 and p<0.005 for latitudes >40° and 20°-40° respectively).The pattern of monthly fluctuation in onset of SUFE very closely mirrored the monthly pattern of variation for serum 25-hydroxyvitamin D3. There was a very strong positive correlation (Spearman rank rho = + 0.8, p = 0.001).There is a monthly variation in incidence of SUFE. The degree of variability increases with increasing latitude. There may be an association with vitamin D. We hypothesise that elevated serum 25-hydroxyvitamin D3 accelerates growth thus rendering the growth plate vulnerable to slippage in analogous manner to the pubertal growth spurt.
Slipped capital femoral epiphysis does not appear to be subclinical Rickets in obese children - June 2015
Can Subclinical Rickets Cause SCFE? A Prospective, Pilot Study
J Pediatr Orthop. 2015 Jun 5. [Epub ahead of print]
Arkader A1, Woon RP, Gilsanz V.
1*Children's Orthopaedic Center †Department of Radiology, Children's Hospital Los Angeles, Los Angeles, CA.
Slipped capital femoral epiphysis (SCFE) is a common disorder of the growing hip; however, its etiology remains unknown. Vitamin D (25-OH) is a major regulator of bone homeostasis and calcium metabolism. Vitamin D deficiency is one of the major causes of rickets, and rickets has been associated with SCFE. Increased body mass index (BMI) has been linked to SCFE and obese children are known to have lower vitamin D levels. Therefore, we hypothesize that children who develop SCFE may have subclinical rickets predisposing them to the development of physeal disease.
This was a pilot, prospective study designed to determine the relationship between vitamin D, bone, muscle, and fat in patients with SCFE. We enrolled 20 consecutive patients with idiopathic SCFE aged 9 to 14 years. Upon diagnosis, vitamin D, PTH, T4, and thyroid-stimulating hormone blood levels were obtained. A single-slice computed tomography was used to measure cortical bone density (CBD) of the femur. Demographics, BMI, and the results obtained were compared to generate a relationship between vitamin D levels and SCFE.
Twenty patients were enrolled, 13 males and 7 females, at an average age of 12 years (range, 9 to 14 y), and mean BMI% was 93.9 (range, 81.3 to 99.5). There were 15 stable and 5 unstable SCFE. Overall, mean and SD values for vitamin D, 25-OH were within the normal range (43.9±13.5).
We found no difference in values in vitamin D between nonobese (BMI<95%) and obese (BMI≥95%) subjects (34.8±16.8 vs. 51.6±22.4, P=0.144).
Moreover, we found no difference in CBD between these 2 groups (1126±33.1 vs. 1147±41.2, P=0.333). There was no relation between blood values of vitamin D and measures of CBD.
Although obese children are known to have lower levels of vitamin D and a higher prevalence of SCFE, we found no correlation between low vitamin D and the development of SCFE in this subset of patients.
LEVEL OF EVIDENCE: Level II.