What is the treatment approach for osteochondroma?

Management of Osteochondroma

Surgical excision is the treatment of choice for osteochondromas that are symptomatic, rapidly growing, or show concerning features for malignant transformation, while asymptomatic lesions can be managed with observation and regular follow-up. 1

Risk Stratification and Diagnostic Approach

Risk stratification is essential for determining the appropriate management approach:

• Low risk: Asymptomatic, stable size, no concerning features
• Intermediate risk: Mild symptoms, growing proportionally with skeletal growth
• High risk: Rapid growth, pain, neurovascular compromise, or concerning radiographic features 1

Diagnostic workup should include:

• Plain radiographs in two planes
• MRI to assess cartilage cap thickness (>2 cm suggests malignant transformation)
• CT scan for complex anatomical locations 1

Management Algorithm

1. Observation (for low-risk lesions)

• Recommended for asymptomatic osteochondromas, especially in skeletally immature patients
• Annual radiographic follow-up until skeletal maturity
• Physical examination to assess for changes in size or symptoms
• Patient education regarding potential for spontaneous regression 1

2. Close Monitoring (for intermediate-risk lesions)

• More frequent imaging (every 6 months)
• Consider MRI if any concerning changes develop
• Follow-up until skeletal maturity, then annually for at least 2 years 1

3. Surgical Intervention (for high-risk lesions)

• Indications for surgery:

  • Rapid growth
  • Pain or functional limitation
  • Neurovascular compromise
  • Cartilage cap >2 cm on MRI
  • Growth after skeletal maturity
  • Erosion or destruction of adjacent bones 1, 2

• Surgical approach:

  • Complete resection with a covering of normal tissue
  • Wide surgical margins if malignant transformation is suspected
  • Histopathological examination of the specimen is mandatory 2, 1

Special Considerations

Multiple Osteochondromas

• Patients with multiple osteochondromas (hereditary multiple osteochondromas) require more vigilant surveillance due to higher risk of malignant transformation 2
• These patients should be counseled and followed up appropriately 2

Malignant Transformation

• Risk factors include:
  • Cartilage cap thickness >2 cm on MRI
  • Erosion or destruction of adjacent bones
  • Growth after skeletal maturity 1
• Malignant transformation to chondrosarcoma requires wide surgical excision with negative margins 2

Anatomical Considerations

• Osteochondromas in complex locations (e.g., spine, pelvis) may require specialized surgical approaches
• For example, osteochondromas of the upper cervical spine may be approached via high cervical extrapharyngeal approach 3
• Pelvic or axial skeleton osteochondromas that undergo malignant transformation should be surgically removed with wide margins 2

Follow-up Protocol

• Low-risk lesions: Annual follow-up until skeletal maturity, then as clinically indicated
• Intermediate-risk lesions: Every 6-12 months until skeletal maturity, then annually for at least 2 years
• High-risk or surgically treated lesions: Every 6 months for 2 years, then annually 1

Pitfalls and Caveats

• Incomplete excision may lead to recurrence, particularly in skeletally immature patients 4
• Delaying surgery until skeletal maturity is ideal when possible to reduce recurrence risk and avoid growth disturbances 4
• Osteochondromas in the distal tibia or fibula may cause plastic deformation and pronation deformity of the ankle if left untreated in skeletally immature patients 4
• Always consider the possibility of malignant transformation in adults with growing osteochondromas 5, 6