[Osteoid osteoma. CT guided drilling and radiofrequency ablation]

[Diagnostics and treatment of osteoid osteoma]

BACKGROUND

Osteoid osteoma is the third most common benign bone tumor and typically induces pain that is worse at night.

OBJECTIVE

To identify the epidemiological, pathogenetic, histological and radiological characteristics of osteoid osteoma and to present the broad variety of treatment options.

MATERIAL AND METHODS

This review article summarizes relevant clinical studies and meta-analyses on this topic.

RESULTS

Osteoid osteoma is characterized by a central nidus smaller than 1.5 cm in diameter with surrounding bone sclerosis. In the majority of cases, the tumor occurs in the long bones of the lower extremities and is predominantly manifested in patients aged between 5 and 25 years. Pain is mediated by prostaglandins, which stimulate afferent peripheral nerve fibers. Besides plain radiographs, thin-section computed tomography represents the gold standard of diagnostics but should be complemented by magnetic resonance or nuclear medicine imaging modalities. The conservative treatment consists of long-term therapy with non-steroidal anti-inflammatory drugs. Minimally invasive radiofrequency ablation of the nidus is the current operative treatment of choice.

CONCLUSION

Success rates of radiofrequency ablation and other minimally invasive procedures are high while treatment costs and length of hospital stay are low. Thus, open surgical curettage is reserved for rare indications and en bloc excision of the nidus should only be performed in cases of recurrent lesions.

Percutaneous radiofrequency ablation for osteoid osteoma under guidance of threedimensional fluoroscopy

PURPOSE

To evaluate the outcome of percutaneous radiofrequency ablation under guidance of 3-dimensional fluoroscopy in 17 patients with osteoid osteoma.

METHODS

Records of 11 male and 6 female consecutive patients aged 4 to 28 (mean, 13.8) years who underwent radiofrequency ablation under guidance of 3-dimensional fluoroscopy for osteoid osteoma and were followed up for a mean of 15.8 (range, 12-28) months were reviewed. All patients had been treated with analgesics but failed to achieve lasting pain relief. Visual analogue score (VAS) for pain was assessed pre- and post-operatively. Absence of pain was considered recovery.

RESULTS

The mean operating time was 55 (range, 20-95) minutes, and the mean length of hospital stay was 2.8 (range, 2-7) days. The mean amount of radiation was 390.2 (range, 330.5-423.6) mGy/cm. Relief of pain occurred within the first 24 hours in 11 patients and by the end of the first week in 3 patients. Pain persisted in 3 patients at one month; they underwent revision surgery and achieved complete recovery. The mean VAS for pain was 7.2 (range, 6-9) in 17 patients preoperatively and decreased to 0.64 (range, 0-2) in the 14 patients with pain relief and 0.66 (range, 0-1) in the 3 patients after revision surgery. Two patients had severe discharge from the wound secondary to fat necrosis, which resolved within a week with antibiotics and local dressings. No patient had cellulitis, vasomotor instability, neurovascular injury, fracture, or deep infection.

CONCLUSION

Percutaneous radiofrequency ablation under guidance of 3-dimensional fluoroscopy is a viable treatment option for osteoid osteoma.

Evaluation of minimally invasive laser ablation in children with osteoid osteoma

The effects between minimally invasive percutaneous laser ablation and open surgery in the treatment of children with osteoid osteoma were compared in the present study. A total of 72 cases of children with osteoid osteoma were divided into control and observational groups, containing 36 cases in each group. The control group underwent conventional open surgery while the observational group underwent minimally invasive CT guided percutaneous laser ablation. Effects of both operations were compared. The operation duration, blood loss and plaster fixation duration of the observational group were significantly less than those of the control group. The postoperative pain score (VAS) at 1 day and 7 days were significantly lower than that of the control group, the differences were statistically significant (P<0.05). The lesion resection rate, effective rate of bone hyperplasia, effective rate of swelling and effusion and total effective rate of the observational group were significantly higher than those of the control group, the differences were statistically significant (P<0.05). Incidence of adverse reactions of observational group was significantly lower (P<0.05) than that of the control group. However, the difference was not significant when comparing 1-year recurrence rate for the two groups. The minimally invasive percutaneous laser ablation has better surgery effects compared with open surgery in the treatment of children with osteoid osteoma.

Radiofrequency Ablation of Osteoid Osteoma with Use of Intraoperative Three-Dimensional Imaging and Surgical Navigation

Introduction

During the performance of radiofrequency ablation of osteoid osteomas, the use of intraoperative cone-beam computed tomography (CT) imaging with surgical navigation lowers radiation exposure while allowing real-time targeting of the nidus.

Step 1 Preoperative Planning

Review all images to confirm a high level of confidence in the radiographic diagnosis.

Step 2 Patient Positioning and Setup

Be sure to position and set up properly.

Step 3 Placement of Tracking Optical Array

Attach the optical array to the target bone.

Step 4 O-Arm Setup Initial CT Imaging for Surgical Navigation and Remote Mouse Registration

Set up the intraoperative CT (O-Arm) machine and acquire the initial images for surgical navigation.

Step 5 CT Data Interpretation and Approach Planning

Analyze the initial images, rotated or positioned as necessary, to allow you to proceed with the planned direction and angle of approach to the nidus.

Step 6 Surgical Navigation Setup

Register the surgical instruments with the surgical navigation unit.

Step 7 Nidus Localization and Kirschner Wire Insertion

Target the nidus and then insert the Kirschner wire into its center.

Step 8 Exchanging Kirschner Wire for a Radiofrequency Probe

Once the accuracy of the Kirschner wire placement is confirmed, exchange it for the radiofrequency probe and perform a CT scan to confirm proper probe placement.

Step 9 Confirmation of RFA Probe Placement

Perform a CT scan to confirm proper placement of the probe within the center of the nidus.

Step 10 Activation of the Radiofrequency Probe and Closure

Perform the radiofrequency treatment to ablate the cells within the nidus.

Results

We conducted a study of three different techniques of radiofrequency ablation.IndicationsContraindicationsPitfalls & Challenges.

[Osteoid osteoma. X-ray-controlled resection and histologic verification using a minimally invasive diamond bone-cutting system]

BACKGROUND

In recent years, osteoid osteomas have been treated more frequently by means of percutaneous procedures. The main disadvantage in patients with suspected osteoid osteoma is the lack of histological verification. Our study presents the results that we obtained using a minimally invasive diamond bone-cutting system allowing histologic verification.

MATERIALS AND METHODS

Six patients (age 10-20 years) with osteoid osteoma in the lower extremities were subjected to resection of the nidus using a minimally invasive water-cooled diamond bone-cutting system. All specimens were histologically processed and diagnosed.

RESULTS

In all patients the nidus was resected successfully, and the diagnosis was histologically confirmed. The mean operating time was 22.8 min. All patients were allowed full weight-bearing immediately, and hospitalization was a maximum of 2 days. All patients were free of pain and relapse-free during the entire 2-year postoperative follow-up.

CONCLUSION

In selected localizations with a clearly visible nidus, the minimally invasive diamond bone-cutting system presented here offers an alternative to the established surgical and percutaneous procedures for treating osteoid osteomas. This procedure combines the advantages of a minimally invasive technique with the option of histological verification of the diagnosis and correct nidus ablation.

Computed tomography-guided radiofrequency ablation of osteoid osteomas

PURPOSE

To report on 14 patients with osteoid osteomas treated by computed tomography-guided radiofrequency ablation.

METHODS

Nine males and 5 females aged 13 to 45 (mean, 25) years with osteoid osteomas were included. The proximal tibia was the commonest site involved. A bipolar 18-gauge radiofrequency probe with a 9- mm active tip was used. A 4.5-mm hollow drill was introduced into the nidus. Energy application was started at 2 W and increased to a maximum of 5 W. Heat was applied for 4 to 6 minutes at 90 degrees Celsius.

RESULTS

12 (86%) of the 14 patients had prompt pain relief; the remaining 2 underwent a repeat ablation. After a mean follow-up period of 19 (range, 9-25) months, no patient had pain recurrence.

CONCLUSION

Radiofrequency ablation is a minimally invasive and cost-effective treatment for osteoid osteomas.