Osteogenesis Imperfecta, Emergency Medicine

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Osteogenesis Imperfecta, Emergency Medicine

Basics

Description

Personnel should obtain information about mechanism or social factors that point toward pathologic fracture vs. nonaccidental trauma. ‚

756.51 Osteogenesis imperfecta ‚

• Inherited abnormality ofprocollagen amino acid sequence
• Bone hypomineralization and incomplete ossification result in brittle bones.
• Abnormal collagen affects all connective tissue to varying degrees.
• Time course is variable:Most cases involve fractures during childhood followed by quiescence during adolescence and early adulthood.

• Most cases involve fractures during childhood followed by quiescence during adolescence and early adulthood.

Etiology

• Procollagen defects result in abnormalities of bone and connective tissue matrix.
• Defects in different sites on procollagen protein chain result in more severe forms.
• Defects are inherited, either autosomal recessive (generally milder) or autosomal dominant (more severe).
• Lethal cases involve sporadic or new mutations.
• Ehlers " “Danlos syndrome involves mutations of the same procollagen protein in different locations.

• Most cases involve pathologic fractures during childhood.
• Multiple fractures often initiate evaluation for abuse, but the possibility of pathologic fractures also should be considered.

Diagnosis

Signs and Symptoms

• Multiple heritable defects that lead to brittle bones:Often associated with other connective tissue abnormalities
• A suspected fracture with a relatively minor mechanism or a history of multiple fractures in a child suggests the diagnosis.
• Careful social history with consideration for the possibility of nonaccidental trauma
• Bones:Multiple recurrent fractures (especially in long bones) are the hallmark of this disease.Fractures may be present at birth or may recur in the elderly.Shortened or bowed limbs, pectus excavatum, curving of long bones, vertebral compression fractures, scoliosis, kyphosis, and abnormal skull shapeAll bones are affected to some extent (see Imaging/Special Tests).
• Eyes:Blue sclerae are another hallmark of this disease.No visual changes are reported.
• Ears:Hearing loss usually begins in adolescence; >90% of patients have some deficit by age 30 yr.Hearing loss is generally sensorineural, although some middle ear abnormalities have been demonstrated.Academic difficulties should raise suspicion of possible hearing deficits.
• Other:Discolored, fragile, and abnormal shape of teethShares several features with Ehlers " “Danlos syndrome:Loose jointsValve problemsVascular abnormalities
• Thyroid abnormalities may be seen.
• Extreme cases may result in perinatal death.

• Often associated with other connective tissue abnormalities

• Multiple recurrent fractures (especially in long bones) are the hallmark of this disease.
• Fractures may be present at birth or may recur in the elderly.
• Shortened or bowed limbs, pectus excavatum, curving of long bones, vertebral compression fractures, scoliosis, kyphosis, and abnormal skull shape
• All bones are affected to some extent (see Imaging/Special Tests).

• Blue sclerae are another hallmark of this disease.
• No visual changes are reported.

• Hearing loss usually begins in adolescence; >90% of patients have some deficit by age 30 yr.
• Hearing loss is generally sensorineural, although some middle ear abnormalities have been demonstrated.
• Academic difficulties should raise suspicion of possible hearing deficits.

• Discolored, fragile, and abnormal shape of teeth
• Shares several features with Ehlers " “Danlos syndrome:Loose jointsValve problemsVascular abnormalities

• Loose joints
• Valve problems
• Vascular abnormalities

Essential Workup

• Diagnosis is usually made as combination of clinical and radiographic findings.
• History of repeated fractures or fractures with unimpressive mechanism
• Thorough search for other tender areas and evaluation of eyes, teeth, and joints is important for diagnosis.
• Careful exam of neurovascular status distal to fracture

Diagnosis Tests & Interpretation

• Evaluate for metabolic derangements such as hyperparathyroidism, vitamin C or D deficiencies, and calcium/phosphate abnormalities.
• DNA studies may be indicated for familial analysis, prenatal testing, and genetic counseling.
• Tissue biopsy is controversial but may help differentiate from tumors.

• Radiographs of fracture sites:May reveal osteopenia (usually mild)Crumpled long bones ( "accordion femora " ť)Incomplete ossification at physes
• Skeletal survey is mandatory, especially in children.
• Skull films may show wormian appearance of irregular ossification.
• Popcorn-like deposits on long-bone ends are poor prognostic finding.
• Formal audiologic testing as outpatient is required in older patients.

• May reveal osteopenia (usually mild)
• Crumpled long bones ( "accordion femora " ť)
• Incomplete ossification at physes

Differential Diagnosis

• Nonaccidental trauma in children
• Ehlers " “Danlos syndrome
• Hypophosphatasia
• Achondroplasia
• Scurvy
• Congenital syphilis
• Celiac disease

Treatment

Pre-Hospital

Initial Stabilization/Therapy

• Airway management and resuscitation as indicated
• Fracture immobilization/splinting

Ed Treatment/Procedures

• Specific fracture management dictated by type and location of injury
• Orthopedic consultation regarding need for traction or operative fixation
• No specific treatment for osteogenesis imperfecta exists at present.

Medication

• Pain medications as indicated
• Elderly women may benefit from calcium (1 " “1.5 g/d) and estrogen replacement (0.625 mg/d).

Follow-Up

Disposition

• Admission is determined by multiple trauma or operative needs for fracture repair.
• Pediatric patients may need admission to investigate possibility of nonaccidental trauma.

• Patients may be considered for outpatient management if isolated fracture is present and appropriate home resources are available.
• Most patients should be discharged with orthopedic and primary physician follow-up.

• Orthopedic referral is driven by the acute injury.
• The presence of fractures in multiple locations or at different times also suggests nonaccidental trauma, which should prompt acute consultation and/or referral per local protocol.

Follow-Up Recommendations

• Follow-up is generally driven by the acute injuries.
• Follow-up with the primary physician should be instituted to encourage treatment and monitoring of the disease.

Pearls and Pitfalls

• The most challenging aspect of caring for these patients is differentiating between pathologic fractures associated with osteogenesis imperfecta and nonaccidental trauma. With any questions, acute consultation and/or referral should be initiated per local protocol.
• It is a myth that children with osteogenesis imperfecta feel less pain than other patients.
• Predisposition to respiratory infections

Additional Reading

• Bishop ‚ N. Osteogenesis imperfecta. Medicine. 2005;33(12):67 " “69.
• Prockop ‚ DJ. Heritable disorders of connective tissue. In: Wilson ‚ JD, et al., eds. Harrisons Principles of Internal Medicine. 12th ed. New York, NY: McGraw-Hill; 1991:1860.
• Rauch ‚ F, Glorieux ‚ FH. Osteogenesis imperfecta. Lancet. 2004;363(9418):1377 " “1385.
• Shapiro ‚ JR, Sponsellor ‚ PD. Osteogenesis imperfecta: Questions and answers. Curr Opin Pediatr. 2009;21(6):709 " “716. www.oif.org

See Also (Topic, Algorithm, Electronic Media Element)

Codes

ICD9

ICD10

SNOMED

• 78314001 Osteogenesis imperfecta (disorder)
• 385482004 osteogenesis imperfecta type I (disorder)