What is the best management approach for aneurysmal bone cysts?

Management of Aneurysmal Bone Cysts

Surgical excision with complete curettage is the optimal treatment for aneurysmal bone cysts to minimize recurrence risk and improve quality of life outcomes. 1, 2

Clinical Overview

Aneurysmal bone cysts (ABCs) are benign but locally aggressive lesions that most commonly affect children and young adults. They present as expansile osteolytic lesions with varying potential for local aggressiveness. Despite being benign, they can cause significant morbidity through bone destruction, pain, and potential neurological compromise if located in the spine.

Diagnostic Approach

• Imaging studies: Initial evaluation should include plain radiographs followed by MRI and/or CT to assess:

  • Extent of bone destruction
  • Soft tissue involvement
  • Presence of fluid-fluid levels (characteristic of ABCs)
  • Relationship to adjacent neurovascular structures

• Biopsy: Often necessary to confirm diagnosis and rule out other conditions that may mimic ABCs (e.g., telangiectatic osteosarcoma, giant cell tumor)

Treatment Algorithm

1. Standard Treatment: Curettage with Adjuvants

• Primary approach: Thorough curettage (manual + high-speed burr) with local adjuvants and bone grafting 1, 3

  • Provides direct access to remove all pathological tissue
  • Allows for definitive histological diagnosis
  • Recurrence rate: 9-27% depending on thoroughness of curettage 3

• Adjuvant options:

  • Phenolization (chemical cauterization)
  • Cryotherapy
  • Argon beam coagulation
  • Bone cement

2. Spine-Specific Management

For ABCs located in the spine, treatment should be particularly aggressive due to higher risks:

• Complete excision should be the goal to minimize recurrence (1/13 with total excision vs. 4/5 with subtotal excision) 4
• Surgical approach depends on location:
  • Posterior approach for posterior element involvement
  • Combined anterior-posterior approach for lesions involving the vertebral body 4, 5
• Spinal stabilization may be required if the lesion has caused significant bone destruction or instability

3. Alternative Approaches for Difficult Locations

For lesions in surgically challenging locations or patients who are poor surgical candidates:

• Selective arterial embolization (SAE):

  • Useful as pre-operative procedure to reduce intraoperative bleeding
  • Primary treatment for spinal lesions that are difficult to access surgically 1

• Sclerotherapy:

  • Injection of sclerosing agents (e.g., Polidocanol)
  • May require multiple sessions
  • Can achieve stable disease in some patients 3

• Minimally invasive options:

  • "Curopsy" (combined curettage and biopsy)
  • Radiofrequency thermal ablation (RFTA)
  • Percutaneous demineralized bone matrix (DBM) grafting 1

4. Medical Management

• Denosumab (RANKL inhibitor):

  • Particularly useful for surgically challenging locations (spine, sacrum)
  • Can stabilize disease and potentially avoid more invasive procedures 3

• Bisphosphonates:

  • May help stabilize lesions
  • Often used as adjunctive therapy

Monitoring and Follow-up

• Regular radiographic follow-up is essential:

  • Every 3 months for the first year
  • Every 6 months for the second year
  • Annually thereafter for at least 5 years

• MRI should be performed if there is clinical suspicion of recurrence

Key Considerations for Optimal Outcomes

• Location matters: Spinal ABCs require more aggressive management due to potential neurological complications and higher recurrence rates 4, 5

• Complete excision: Total removal significantly reduces recurrence rates compared to subtotal resection (7.7% vs 80%) 4

• Adjuvant therapy: While phenolization has been traditionally used, evidence suggests it may not significantly affect recurrence rates (9% with phenol vs 27% without) 3

• Multidisciplinary approach: Complex cases benefit from collaboration between orthopedic surgeons, neurosurgeons, interventional radiologists, and oncologists

Common Pitfalls to Avoid

1. Inadequate curettage: Failing to remove all pathological tissue is the most common cause of recurrence

2. Misdiagnosis: ABCs can be confused with other bone lesions; definitive histological diagnosis is crucial

3. Neglecting structural integrity: Extensive curettage without appropriate reconstruction can lead to pathological fractures

4. Underestimating blood loss: ABCs are highly vascular lesions; preoperative embolization should be considered for large lesions

5. Insufficient follow-up: Regular monitoring is essential to detect recurrence early

By following this management approach, patients with aneurysmal bone cysts can achieve excellent outcomes with minimal morbidity and low recurrence rates.