Introduction
Bone maturation measures the recognizable and reproducible sequence of changes noted in the appearance of the skeleton during childhood. Healthcare professionals assess bone maturation by estimating bone age with the help of radiographs of certain bones. A delay in skeletal development can occur associated with various disorders and other factors. This article will discuss the delay in bone maturation in detail.
What Is Bone Age?
A study of bone age is essential to diagnose a delay in the rate of bone maturation in children. Determining bone age helps assess the physiological maturity of an individual's skeleton. It helps diagnose the underlying cause of the retardation, such as an endocrine disorder, growth abnormalities, or other conditions. Generally, bone age refers to the measure of the development of a person's skeletal system. Bone age is different from a person's biological age (an accurate measure of lifespan by assessing the changes in the genetic material) or chronological age (the number of years passed from the time of birth).
What Happens During Delayed Bone Maturation?
A delay in bone maturation can affect the physiological growth of the individual. When there is retardation or delay in bone maturation, the person's bones mature slower than their age, resulting in growth delay. These individuals reach puberty later than other persons of the same chronological age. They might also indicate an underlying health condition or a disorder. Early diagnosis of the causative factor for the delay in bone maturation can help initiate treatment in the early stages.
What Are the Common Causes of Delayed Bone Maturation?
A delay in the pace of skeletal maturation can be associated with various causes, such as endocrine disorders, chronic non-endocrine disorders, nutritional causes, syndromes, and idiopathic causes. Typical conditions are mentioned below.
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Endocrine Disorders: Endocrine disorders occur when there is an improper functioning of the endocrine gland (an organ that releases hormones and controls the growth and development of an individual). These disorders can alter the bone age of an individual.
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Hypothyroidism: A condition in which the thyroid gland produces insufficient thyroid hormone production. Congenital conditions (present at birth) of hypothyroidism can arrest growth and cause a delay in bone age and short stature during birth. Histomorphologic studies of the thigh bone, an upper arm bone, and a navicular bone show defects in the ossification center (the primary and the secondary point involved in the formation of bone).
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Hypopituitarism With Growth Hormone Deficiency: A condition with a deficiency of growth hormone released by the pituitary gland. Patients with untreated growth hormone deficiency disorder show delayed bone maturation.
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Hypogonadism: A condition in which there is insufficient production of sex hormones by the body's sex glands (gonads). Patients with this condition, especially during the pubertal period, show a lack of circulating sex hormones and other pubertal hormones, another primary factor for the delay in bone maturation.
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Cushing's Disease: A condition that occurs due to excessive production of cortisol hormone by the pituitary gland.
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Juvenile Diabetes: Diabetic condition diagnosed in children and young people.
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Adrenal Insufficiency: Occurs in Addison's disease.
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Hypoparathyroidism: Insufficient production of parathyroid hormones by the parathyroid gland.
What Are the Non-Endocrine Causes of Delayed Bone Maturation?
1. Systemic Condition: Children with chronic heart disease, liver and kidney diseases are associated with delayed bone maturation. Other systemic conditions associated with malnourishment such as intestinal inflammatory diseases, Crohn's disease (an inflammatory bowel disease), celiac disease (a chronic inflammatory digestive disorder), and cystic fibrosis (a condition affecting the lungs, digestive system, and other organs) may show delayed bone age. Patients with conditions like anorexia (an eating disorder) and under a state of abuse or stress show the presence of delayed bone maturation.
2. Syndromes:
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Turner's Syndrome: A genetic condition that usually affects females. Even though there is sufficient production of growth hormones in patients affected with this condition, there is an impairment in using these hormones.
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Down's Syndrome: A genetic condition that shows delayed bone maturation.
3. Family History: A familial history of retarded growth maturation may be another factor.
4. Pre-Mature Babies - Babies born before the gestation of 37 weeks.
5. Teratogenecity - Infant of a pregnant mother who ingested certain drugs during pregnancy.
How Is Delayed Bone Maturation Diagnosed?
The interaction and activation of an intricate series of physiological mechanisms achieve bone maturity. Bone maturation begins in the primary ossification center and later with subsequent various remodeling stages and finally reaches the final shape. Bone maturation is assessed by evaluating the centers of maturation. For example, in long bones, the center of maturation is the epiphysis (round portions of the long bones). For many years, the gold standard method of assessing bone maturation has been through radiographic assessment of wrist and knee regions. They are compared with radiographic images in the standard atlas of bone development. This standard atlas of bone development is created based on the data of many children with the same chronological age.
The healthcare professionals will perform various tests like blood tests to assess the levels of certain hormones, the presence of chromosomal abnormalities, and the patient's overall health. The doctor may perform radiographic investigations like X-rays to visualize the skeletal development of the patient. X-rays of the patient's hands or wrist may be carried out to estimate bone age and determine bone maturation. Generally, bones have various growth plates at the ends that increase the length and width of the bone. These areas are usually visible in the radiographic examination.
Conclusion
A delay or retardation in bone maturity results in the growth delay of the affected individual. Bone maturation is affected by various factors like endocrine disorders, systemic conditions, or other factors. It can be assessed by determining the bone age of the patient. Bone age is assessed by radiographic interpretation of the child's wrist or hand. Treatment for delayed bone maturation is wholly based on the underlying cause of it. Delayed bone maturation because of hormonal changes may be treated with supplemental hormone therapy when diagnosed early. Children suspected of growth retardation should consult a healthcare professional to determine its etiology.
