Treatments

Osteoid Osteoma Radiofrequency / Microwave Ablation

Posted on by Prof. Dr. Özgür KILIÇKESMEZ

Osteoid osteoma is a benign bone tumor commonly seen in young adults. This tumor often causes pain that worsens at night, reducing patients’ quality of life. While surgical resection was the only treatment for many years, radiofrequency ablation has recently emerged as an effective alternative. This method is less invasive and accelerates patients’ recovery. Therefore, it reduces both cost and hospital stay duration.

What Is Radiofrequency Ablation for Osteoid Osteoma?

Radiofrequency ablation for osteoid osteoma is an effective treatment method. Offering a modern alternative to surgery for this tumor of unknown etiology, advanced techniques use radiofrequency energy to target tumor tissue. During this procedure:

  • Radiofrequency waves are applied directly to the tumor.
  • High-frequency currents heat and destroy tumor tissue.

Patients experience less pain and faster recovery, with significantly shorter hospital stays, reducing overall treatment cost. Radiofrequency ablation is especially preferred in young adults, improving quality of life and function, making it a valuable option for osteoid osteoma patients.

Where Does Osteoid Osteoma Occur in the Body?

Osteoid osteoma can develop in various skeletal regions, with location directly affecting clinical presentation. Most commonly, these tumors occur in long bones of the lower extremities, particularly:

  • Femur (thigh bone)
  • Tibia (shin bone)

They are usually localized in the diaphysis or metaphysis of these bones. However, osteoid osteoma can also appear in:

  • Small bones of the hands and feet
  • Spine, especially lumbar vertebrae

In the spine, tumors often reside posteriorly, causing painful spinal curvature. Periarticular tumors can lead to joint effusion and inflammatory arthritis–like symptoms. Thus, osteoid osteoma’s clinical features vary by location, guiding treatment decisions.

What Happens After Osteoid Osteoma Formation?

Osteoid osteoma is a small benign lesion seen in children and young adults, characterized by a central nidus of 1.5–2 cm diameter. The nidus contains varying degrees of bone mineralization, surrounded by reactive sclerotic bone. Osteoid osteoma is classified into three main types:

  • Cortical osteoid osteoma: the most common form.
  • Medullary osteoid osteoma: often in femoral neck and small bones.
  • Subperiosteal osteoid osteoma: may occur on joint surfaces.

Cortical lesions display a classic nidus with surrounding sclerosis. Medullary and subperiosteal types have less sclerosis, sometimes complicating diagnosis. Each type requires specific diagnostic and therapeutic approaches based on its bone location.

Which Imaging Methods Are Used?

Accurate diagnosis of osteoid osteoma relies on imaging. Initial plain radiographs may reveal a small round or oval nidus with surrounding sclerosis but can miss less sclerotic lesions. Computed tomography (CT) is the most effective:

  • Clearly shows the nidus and surrounding sclerosis.
  • Detects small or minimally sclerotic lesions.
  • Details vascularity and surrounding structures.

Magnetic resonance imaging (MRI) is sensitive for marrow and soft‑tissue inflammation; the nidus often appears low‑to‑intermediate signal but must be correlated with CT to avoid misdiagnosis. Bone scintigraphy can identify larger lesions by showing intense radiotracer uptake with a “double density” sign.

How Is Radiofrequency Ablation Performed?

Image of osteoid osteoma ablation procedure

Radiofrequency ablation is a minimally invasive technique offering comfort and rapid recovery. Patients typically return to normal activities quickly. The procedure is performed under sterile conditions with CT guidance and an RF generator. Steps include:

Patient Preparation:

  • Position the patient prone, supine, or lateral as needed.
  • Place two grounding pads on the skin and connect to the RF generator.

Local Anesthesia:

  • Local anesthetic is usually sufficient for pain control.
  • Type of anesthesia chosen based on patient’s condition and cooperation.

Lesion Localization and Access:

  • Use CT to pinpoint the nidus.
  • Perform multiplanar reconstructions to plan the safest trajectory.
  • Avoid vessels and nerves.

Cannula Placement:

  • Advance a coaxial introducer cannula to the nidus.
  • Confirm position with repeat CT scans.

Bone Penetration and Electrode Insertion:

  • Insert a Kirschner wire through the cannula into the bone.
  • Measure distance to the nidus precisely.
  • Exchange wire for the RF electrode and reconfirm placement.

Ablation:

  • Connect the electrode to the RF generator and begin ablation.
  • Heat the nidus to the target temperature for the prescribed duration.
  • Maintain optimal temperature and time for complete ablation.

Post‑Procedure Care:

  • Obtain a final CT to check for soft‑tissue injury.
  • Remove the electrode and cannula, apply local anesthetic.
  • Cover the entry site with a sterile dressing.

Discharge and Follow‑Up:

  • Patients are usually discharged the same day.
  • Schedule a follow‑up MRI or CT at 30 days.

What Is the Post‑Ablation Recovery Process?

After RF ablation, patients are monitored in recovery for about four hours. Most are discharged the same day. Pain peaks within the first 72 hours and is managed with analgesics. Recovery guidelines:

  • Return to daily activities by the end of week one.
  • Avoid heavy physical exertion for three months.
  • Night pain relief observed within days.

Recurrence occurs in about 10 % of cases, potentially requiring a second ablation. Patient health and recovery remain top priority throughout.

What Are the Advantages of RF Ablation?

Radiofrequency ablation (RFA) for osteoid osteoma offers low recurrence rates and high pain relief efficacy. In non‑spinal lesions, recurrence rates drop to around 2 %. Studies report 95 % of patients achieving significant or complete pain relief. RFA also has minimal complication risk, with most patients feeling relief within days.

High Success Rate:

  • Recurrence rates of 10–16 %.
  • 95 % pain relief success.

Minimal Complications:

  • Transient post‑procedure pain manageable with medications.

Bone Preservation:

  • Maintains bone integrity.
  • Minimizes collateral tissue damage.

Cost‑Effectiveness:

  • Lower cost compared to surgical resection.

Additional Resources and Documents

https://ozgurkilickesmez.com/wp-content/uploads/2024/07/Computed-tomography-guided-radio-frequency-ablation-of-osteoid-osteomas-in-atypical-locations.pdf

https://ozgurkilickesmez.com/wp-content/uploads/2024/07/Percutaneous-image-guided-ablation-of-bone-and-soft-tissue-tumours.pdf

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