The Seasonality of Slipped Upper Femoral Epiphysis - Meta-Analysis: A Possible Association with Vitamin D

Abstract

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.

Seasonal Variation in Slipped Capital Femoral Epiphysis: New Findings Using a National Children’s Hospital Database

“…There are many potential explanations for these findings. An intriguing one is that SCFE may represent a rachitic state, which has been postulated by several authors (3,5,6). Such seasonal variation could be explained by differences in vitamin D production and levels at different times of the year.…”

“…Many questions have arisen from these studies, especially differences between varying degrees of latitude (3,5) how can that be explained? Does such variation represent temperature differences, sunlight exposure with different amounts vitamin D production (6), or other even more esoteric climactic variables? With the advent of large national data bases, seasonal variation in SCFE, if it does exist, can be more fully explored.…”

A New Look on the Epidemiology of Slipped Capital Femoral Epiphysis: A Topic Revisited

“…Seasonal variation, position in the country (latitude), and vitamin D metabolism have been suggested to have possible clinical links to developing SCFEs. [27][28][29][30][31][32][33] These likely are multifactorial and include activity outdoors, seasonal sports, skin color, and UV light exposure. The majority of human vitamin D3 is obtained through the interaction between sunlight (UVB) and 7-dehydrocholestol.…”