Very Large Sizes in Adolescents : Tibial and Femoral EPIphysiodesis
Very Large Sizes in Adolescents : Tibial and Femoral EPIphysiodesis
The very large sizes can be very disabling and at the origin of a difficult psychological
 experience. Some families are in demand for a growth-curbing treatment. Currently, only
 hormonal treatments are offered in France but they are at the origin of many side effects.
 Northern European countries applied a surgical technique, deviated from the one used for a
 long time in leg asymmetries, to sterilize the proximal tibial and distal femoral growth
 cartilage, with most of the growth taking place at this level. The goal of this project is to
 be able to offer this technique to families in demand.
By "very large size" we mean a size greater than +3 SD (standard deviation) on the updated
 French reference curves. Most of the very large sizes are constitutional.

 The first step in the management of the paediatrician endocrinologist with very large body
 height is to collect the auxological parameters (family height, not just parental height,
 birth height, weight, height, head circumference, body mass index, height, sitting height)
 and plot the corresponding adolescent growth curves. The clinical stage (interview, clinical
 examination) will attempt to rule out a diagnosis other than a very large constitutional
 size: a recent statural acceleration related to a hormonal cause with specific medical
 treatment (hyperthyroidism or hyper androgeny or early puberty or acromegaly or more rarely
 estrogen deficiency by mutation of the CYP19A1 aromatase gene or by mutation of the ERα
 receptor) and will seek a syndrome in which the very large size is a sign among others.

 Among the main syndromes are Klinefelter's syndrome (prevalence 1 person/1,200 or 1/600 boy
 births), Marfan's syndrome (about 1/6,000 births, prevalence 1 to 5 persons/ 10000), triple X
 syndrome (1 to 5 persons/10,000).

 Additional examinations will be guided by diagnostic hypotheses; the very large
 constitutional diagnosis remains a diagnosis of elimination.

 The very large constitutional size is defined as family, i.e. related to the size of at least
 1 of the 2 parents or close family members of the parents.

 The target size can be calculated as an indication:

 -  Target size =[father size (cm) + mother size (cm) +13] /2 for boys

 -  Target size =[father size (cm) + mother size (cm) -13] /2 for girls However, experience
 shows that the target size is a poor prognostic tool in very large constitutional sizes:
 growth is always above it.

 Very large constitutional size remains the most frequent diagnosis among etiological
 diagnoses of very large sizes.

 The therapeutic question follows the diagnostic stage. Only very large sizes secondary to a
 hormonal cause can benefit from specific medical treatment.

 Outside these situations, a therapeutic discussion will be proposed based on the size
 prognosis estimated by the pediatrician endocrinologist. In the event of a predicted very
 large size and if this represents an inconvenience for the adolescent, the paediatrician
 endocrinologist may propose a growth-blocking treatment.

 Very large sizes can be disabling and cause a difficult psychological experience, so some
 families are in need of growth-restricting treatment, especially girls who consult more often
 and earlier than boys.

 The estimation of adult prognosis by the pediatrician endocrinologist, formerly based on
 Bayley and Pinneau's tables, has been replaced by more modern software integrating Greulich
 and Pyle's tables, Tanner Whitehouse 2 and 3, and taking into account parental sizes and
 ethnic origin. This automated reading of bone maturation makes it possible to be more
 accurate in predicting final size, an essential step before any therapeutic discussion.

 In the international literature (mainly the United States, Northern Europe and Australia) it
 is relatively consensual to consider a growth-blocking treatment for a prognosis ≥185 cm for
 girls and ≥ 200 cm for boys. For our study, we will use a prognosis ≥ 184 cm for girls and ≥
 198 cm for boys, which corresponds to a size of +3 SD on the updated French curves.

 Currently in France, the therapeutic possibilities to slow down growth and thus reduce the
 final adult size are:

 -  Either medical treatments: excluding MA and causing many side effects;

 -  Or surgical treatments: performed anecdotally in France and based on publications from
 Northern Europe.
Inclusion Criteria:

 -  Adolescent (e) consultant for very large size with a demand for growth inhibition

 -  Very large idiopathic or secondary height without any other etiological treatment
 possible

 -  Tanner score ≥ 3 for boys and ≥ 2 for girls

 -  A0 ≤ 14 years for boys and ≤ 12.5 years for girls

 -  A chronological age of 10 to 16 for boys and 8 to 14 for girls

 -  Actual size from minimum 167.5 cm to 10 years old to at least 180 cm to 16 years old
 for boys and from minimum 160 cm to 8 years old to at least 174 cm to 14 years old for
 girls

 -  Predicted height ≥ 198 cm for boys and ≥ ≥ 184 cm for girls (refer to chapter 6.6)

 -  Radiological persistence of tibial and femoral tibial cartilage estimated residual
 growth ≥ 8 cm

 -  Absence of psychological contraindication to a curbing treatment of growth

 -  Agreement of the holders of the parental authority and the teenager for a surgery of
 epiphysiodesis type

 -  Agreement of the holders of the parental authority and the teenager to take part in
 the study

 -  Affiliated to a social security scheme

 Exclusion Criteria:

 -  Very large size related to a medically curable etiology (hypersecretion of growth
 hormone called acromegaly)

 -  Refusal of the holders of the parental authority or the teenager for a surgery of the
 epiphysiodesis type

 -  Refusal of the holders of the parental authority or the teenager to take part in the
 study

 -  Medical or psychological contraindication to surgery.