Q78.6 Multiple congenital exostoses

Name of the Condition

• Multiple congenital exostoses

Summary

Multiple congenital exostoses is a genetic disorder characterized by the development of multiple benign bone growths (exostoses) that protrude from the surface of bones. These growths, also known as osteochondromas, typically occur near the growth plates and can affect bone development, leading to skeletal deformities and potential complications.

Causes

This condition is primarily caused by mutations in the EXT1 or EXT2 genes, which are involved in the regulation of bone growth. Most cases are inherited in an autosomal dominant pattern, meaning a single copy of the mutated gene from one parent is sufficient to cause the disorder. Spontaneous mutations can also occur.

Risk Factors

• Family history of multiple congenital exostoses
• Inheritance of mutated EXT1 or EXT2 genes
• Parental consanguinity (increased risk for recessive forms, though rare)

Symptoms

• Multiple painless bony lumps near joints
• Limited joint mobility or stiffness
• Skeletal deformities (e.g., bowing of long bones)
• Short stature or disproportionate limb lengths
• Nerve compression symptoms (e.g., numbness, weakness) if growths press on nerves

Diagnosis

Diagnosis involves clinical evaluation of physical symptoms and family history, often supported by imaging (e.g., X-rays, MRI) to visualize bone growths and assess their impact on surrounding structures. Genetic testing may confirm mutations in the EXT1 or EXT2 genes.

Treatment Options

• Surgical removal of symptomatic exostoses
• Orthopedic interventions to correct deformities
• Physical therapy to improve mobility and strength
• Monitoring for potential complications (e.g., malignant transformation)

Prognosis and Follow-Up

Most individuals with multiple congenital exostoses have a normal life expectancy, but regular monitoring is essential to detect complications such as nerve compression or malignant changes. Follow-up may include periodic imaging and clinical assessments, especially during growth periods.

Complications

• Malignant transformation of exostoses (rare)
• Nerve or blood vessel compression
• Skeletal deformities affecting mobility
• Growth disturbances leading to limb length discrepancies

Lifestyle & Prevention

• Avoid activities that may traumatize exostoses to reduce fracture risk
• Maintain regular physical activity to preserve joint function
• Use protective gear during sports or physical activities
• Follow up with orthopedic specialists for ongoing care

When to Seek Professional Help

Seek medical attention if you experience:

• Sudden increase in size or pain of a bony lump
• New or worsening nerve compression symptoms (e.g., numbness, weakness)
• Difficulty with movement or joint function
• Signs of infection or inflammation around a growth

Tips for Medical Coders

Document the presence of multiple exostoses, their location, and any associated complications (e.g., deformities, nerve compression) to support accurate coding. Ensure clinical notes specify whether the condition is hereditary or sporadic, as this may impact documentation requirements.