Clinical Assessment Stature

Assessment of stature starts with regular height measurement (Box 1). This requires consistent and correct technique for reliable data. It is helpful, if

Box 1 Assessment of Stature

■ Accurate height measurement

■ Calculation of height velocity

■ Comparison with appropriate growth charts and standards

■ Calculation of mid-parental height range

■ Correct interpretation of data possible, for young people to be measured by the same person at each visit, especially when the young person has significant joint deformities or treatment decisions are being considered, to minimize interobserver error.

Measuring Technique

A correctly installed stadiometer should be used, which is checked regularly for accuracy. The young person should be positioned in bare feet, with their heels, buttocks, and shoulder blades against the back wall/plate. The head should be held so that the Frankfurt plane (the imaginary line from the center of the ear hole to the lower border of the eye socket) is horizontal. The head board should exert a gentle downward pressure to allow good contact with the head. The height should be read at maximum stretch, but without having caused lifting or overextension (2).

When there are significant joint deformities, particularly of the spine and lower limbs, an accurate description of this should be noted, as changing joint deformity (with changing disease activity) can affect the ability to position a young person correctly for measurement and can therefore affect the measurement obtained.

Height measurements should be plotted on an appropriate growth reference chart for sex and age. By definition, short stature is when a person's height is below the 2nd percentile (more than two SD below the mean). Despite this, the person's height may be normal for their genetic potential (compare height percentile to that of the mid-parental height range) or pubertal stage. Pathological short stature is indicated by a poor growth velocity.

Calculation of Height Velocity

Height velocity should be calculated with a minimum of six months between height measurements, as growth does not occur in a smooth linear fashion and often has a seasonal influence. A 1-year interval overcomes the seasonal effect on growth, but may not allow timely recognition of growth slowing.

Height velocity (cm per year)

Current height — Previous height Months between measures

These calculations can then be plotted against recognized standards for sex, age, and pubertal stage (Figs. 3 and 4). Early growth failure can be recognized when height velocities are consistently below the 25th percentile.

The differential diagnosis of short stature and an approach to clinical evaluation and investigation (1) is outlined in Table 2. First an assessment is made between normal variant short stature and pathologic short stature. If pathologic, body proportions are measured to distinguish proportionate from disproportionate. Thirdly, for those with proportionate short stature, timing of onset (pre- or postnatal) is determined to further narrow the likely

Table 2 Differential Diagnosis of Short Stature

Condition

Features/investigations

Normal variants

Familial short stature

Constitutional delay of growth and development

Pathologic

Proportionate

Postnatal: Birth growth parameters appropriate for gestational age Chronic illness and/or malnutrition Endocrine disorders Hypopituitarism Growth hormone deficiency Hypothyroidism Cushing syndrome Psychosocial deprivation

Prenatal: Small at birth for gestational age

IUGR

Chromosomal disorders (including Turner syndrome) Dysmorphic syndromes

Predicted final height within MPHR (albeit short)

Bone age normal for chronological age Normal history and examination Normal height velocity (growth parallel to 3rd percentile for average pubertal development) Bone age delayed by more than 2 SD Delayed puberty and growth spurt (otherwise normal history and examination) Height velocity normal for bone age (growth parallel to 3rd percentile for late pubertal development) Family history delayed puberty Normal final height

Normal US:LS ratio for age (mean 1.0 after 7 yrs)

Normal arm span-height for age (0 cm 8-12 yrs; + 1 cm for females and + 4 cm for males at 14 yrs)

History/examination/screening and confirmatory tests History/examination/ Respective hormone profiles

Social and dietary history/developmental examination

Antenatal/maternal history/examination/

TORCH screen Dysmorphic/congenital anomalies/karyotype

Dysmorphic/congenital anomalies/radiology

(Continued)

Table 2 Differential Diagnosis of Short Stature (Continued)

Condition

Features/investigations

Disproportionate

Abnormal US:LS ratio for age

Abnormal arm span-height for age

Skeletal dysplasias

Skeletal radiology

Rickets

History/examination/calcium/phosphate/

alkaline phosphatase/radiology

Abbreviations: MPHR, mid-parental height range; TORCH, toxoplasmosis, other, rubella, cytomegalovirus, herpes; US:LS, upper body segment height:lower body segment height.

Abbreviations: MPHR, mid-parental height range; TORCH, toxoplasmosis, other, rubella, cytomegalovirus, herpes; US:LS, upper body segment height:lower body segment height.

diagnosis. It should also be noted that these diagnoses are not necessarily mutually exclusive, with some young people having a combination of factors contributing to their short stature. For example, a young person may have familial short stature exacerbated by chronic rheumatic disease and delayed puberty.

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