Childhood bone fractures are common and often cause concern for patients, parents, and clinicians. This concern is especially true when a child has had more than 1 fracture.
Peter J. Tebben, M.D., of the Division of Endocrinology, Diabetes, Metabolism, and Nutrition and the Division of Endocrinology in the Department of Pediatrics at Mayo Clinic, outlines: "Approximately one-third of children will have sustained a fracture by age 18 years. Most of these children do not have an underlying metabolic bone disorder that requires evaluation and treatment. It is often hard to know when to worry about fractures in children and decide who needs further evaluation for potential underlying disease.
"Understanding the typical timing and types of fractures is helpful. The rate of fractures increases substantially during puberty for both boys and girls but to a greater degree for boys. The peak incidence of fractures in girls occurs around 10 to 12 years of age and in boys around 13 to 15 years of age.
"Forearm fractures are by far the most common type of fracture during childhood. However, vertebral compression fractures are distinctly uncommon in children and should always be a cause for concern and additional evaluation."
Children with 1 or 2 traumatic fractures are unlikely to have an identifiable disorder and do not routinely require further evaluation. Dr. Tebben notes: "Obtaining a detailed history about the circumstances surrounding a fracture is important in determining the level of concern. Multiple fractures, atypical fractures (such as vertebral compression fractures), low-trauma fractures, and a family history of metabolic bone disease are all red flags that should prompt further investigation.
"Children with inflammatory bowel disease, celiac disease, chronic glucocorticoid exposure, neuromuscular disorders, and others warrant special attention to optimize bone health, since they are at increased risk for low bone density. A family history of frequent fractures should prompt consideration of inherited conditions, such as osteogenesis imperfecta."
Amy L. McIntosh, M.D., of the Division of Pediatric Orthopedics in the Department of Orthopedic Surgery at Mayo Clinic, says: "Unexplained fractures, especially in infants, mandate consideration of nonaccidental trauma if an underlying bone disorder is not clearly identified.
"Poor fracture healing also should raise suspicion of an underlying bone disease. Most fractures in children show radiographic evidence of callus formation by 3 to 6 weeks. By 8 to 12 weeks, most fractures are united radiographically and no longer require any form of external immobilization."
A basic laboratory evaluation includes such tests as:
Dr. Tebben explains: "The serum concentration of 25-hydroxyvitamin D is the best test to determine whether adequate vitamin D stores are present. The serum concentration of the active metabolite of vitamin D (1,25-dihydroxyvitamin D) can be variable in children with nutritional vitamin D deficiency (low concentration of 25-hydroxyvitamin D) and is usually not helpful in determining vitamin D status.
"Serum alkaline phosphatase values are helpful but can be difficult to interpret in children. Growing children have a markedly greater serum alkaline phosphatase concentration than adults and an appropriate reference range for age and sex should be used. Alkaline phosphatase level will usually be elevated in the context of a recently sustained, healing fracture. Clinical findings supporting a secondary cause of poor bone health should also guide the evaluation."
Dual-energy x-ray absorptiometry (DXA) is a widely available technique for determining bone density. Children with frequent, low-trauma, or atypical fractures are good candidates for bone density measurement.
Dr. Tebben says: "Children with disorders associated with low bone density, such as inflammatory bowel disease, may also benefit from bone density determination. DXA measurements in children should be performed in centers with experience obtaining and interpreting the scan.
"An appropriate normative database is needed for interpretation of the result. The Z-score compares an individual's bone density to an age- and sex-matched normal population and is the appropriate measure to use when interpreting bone density in children. T-scores should never be used in children because they will lead to unnecessary concern and unneeded evaluation."
Adequate intake of calcium and vitamin D is the foundation of any treatment program to promote bone health. The American Academy of Pediatrics currently recommends that all children receive 400 IU of vitamin D daily, which can be obtained through the diet (mainly milk) or through supplementation, or both. The optimal amount of vitamin D intake or serum vitamin D concentration for children has not yet been clearly defined. Avoiding excessive caffeine and soda intake should also be advised.
Dr. Tebben notes: "Bisphosphonates may be beneficial in select children with low bone density and fractures and should be given under the supervision of a clinician experienced with their use in children. Bisphosphonates are not approved by the US Food and Drug Administration for use in children, and only minimal data exist regarding fracture prevention in children."