When should a patient with an enchondroma be referred to orthopedics?

Management of Enchondromas: When to Refer to Orthopedics

Patients with enchondromas should be referred to orthopedics if the lesion is >5-6 cm, located in high-risk areas (pelvis, scapula, femur, tibia, humerus), shows signs of aggressive behavior, is painful without other explanation, or occurs in patients with enchondromatosis syndromes. 1

Indications for Orthopedic Referral

Size and Location

• Size >5-6 cm: Larger enchondromas have higher risk of malignant transformation 1
• High-risk locations:
  • Axial skeleton (pelvis, ribs)
  • Long bones (particularly femur, tibia, humerus)
  • Scapula
  • These locations have higher rates of malignant transformation 1

Concerning Clinical Features

• Pain at the lesion site: Pain without other explanation may indicate malignant transformation 1
• Rapid growth: Any enchondroma showing growth on serial imaging
• Pathologic fracture: Requires orthopedic evaluation and potential surgical intervention 2

Radiographic Features Requiring Referral

• Endosteal scalloping: Erosion of the inner cortex >2/3 of cortical thickness
• Cortical breakthrough/destruction
• Soft tissue extension
• Periosteal reaction
• Lytic areas within the lesion 1, 3

Special Patient Populations

• All patients with enchondromatosis (Ollier disease, Maffucci syndrome):
  • 30% risk of malignant transformation
  • Require orthopedic specialist involvement in their care 1
• Patients with multiple enchondromas: Higher risk of malignant transformation

Initial Diagnostic Workup Before Referral

1. Plain radiographs in two planes as first-line imaging 1
2. MRI of the entire compartment with adjacent joints if:
   • Lesion >5-6 cm
   • Located in high-risk areas
   • Symptomatic without other explanation
   • Shows aggressive features on radiographs 1

Management Algorithm

1. Asymptomatic, small (<5 cm), typical enchondromas in low-risk locations:

   • Regular radiological follow-up is appropriate
   • Physical examination every 6-12 months
   • Plain radiographs every 2-3 years 1, 4

2. Symptomatic enchondromas OR those with concerning features:

   • Immediate referral to orthopedic specialist at a bone sarcoma center 1
   • Biopsy should be performed at a bone sarcoma reference center by the surgeon who will carry out any potential definitive tumor resection 1

3. Patients with enchondromatosis (Ollier disease, Maffucci syndrome):

   • Referral to orthopedic specialist with expertise in bone tumors
   • Whole-body MRI at diagnosis and periodically after age 20 1
   • More intensive surveillance due to higher risk of malignant transformation

Pitfalls to Avoid

1. Attributing pain solely to enchondroma: 65% of patients with enchondromas have adjacent joint problems that are the actual source of symptoms 3

2. Unnecessary biopsy/surgery: The complication rate of enchondroma curettage is considerable (23%), making observation preferable for asymptomatic, typical lesions 4

3. Inadequate imaging: Failure to obtain appropriate imaging can lead to missed diagnosis of aggressive features

4. Overdiagnosis of malignancy: Small, well-defined lesions are often confused with sarcomas due to lack of familiarity with bone tumors 3

5. Inadequate follow-up: Patients with multiple enchondromas or enchondromatosis require lifelong surveillance due to continued risk of malignant transformation 1

By following these guidelines, primary care providers can appropriately identify which patients with enchondromas require orthopedic referral, potentially improving outcomes while avoiding unnecessary procedures for patients with benign, stable lesions.