Radiofrequency ablation in the treatment of osteoid osteoma-5-year experience

Image-guided Ablative Procedures

Various image-guided ablative procedures include chemical and thermal ablation techniques and irreversible electroporation. These have been used for curative intent for small tumours and palliative intent for debulking, immunogenicity and pain control. Understanding these techniques is critical to avoiding complications and achieving superior clinical outcomes. Additionally, combination with immunotherapy and chemotherapies is rapidly evolving. There are numerous opportunities in interventional radiology to advance ablation techniques and seamlessly integrate into current treatment regimens for both benign and malignant tumours.

Radiofrequency ablation of osteoid osteoma at the base of the coracoid process: Report of two cases

If you encounter an unexplained case of bone marrow edema in a young patient, consider the possibility of osteoid osteoma (OO). Even in the presence of a nidus near vital structures, RFA can safely be used to treat OO.

High-intensity focused ultrasound-a needleless management for osteoid osteoma: a systematic review

Osteoid osteoma is one of the most frequent benign musculoskeletal neoplasm. Radiofrequency ablation is the method of choice for non-conservative treatment of osteoid osteoma. Recently, high-intensity focused ultrasound (HIFU) has been proposed as a safer option. The objective of this study is to review the efficacy and side effects of HIFU in the management of osteoid osteoma. A comprehensive search was conducted in PubMed, Science Direct, and Clinical Key until June 30, 2022. Demographic data, baseline characteristics, success rates, pre- and post-procedure pain scores, recurrences, and complications were recorded. Eleven studies were included in this systematic review. Pooled analysis that involved 186 subjects resulted in an overall success rate of 91.94%. Recurrence was reported in two studies, in which it occurred in 4/177 (2.26%) subjects. Skin burn was found in 1 (0.54%) patients. No major or other complications were reported. Three studies compared the success rate of HIFU and RFA. Success rate was slightly higher in the RFA group with insignificant difference (p = 0.15). High-intensity focused ultrasound showed promising results. It offers a safer treatment approach for osteoid osteoma, especially in children, and can be considered for recalcitrant cases after RFA. Nonetheless, more studies are expected in the future.

Is Intraoperative CT Navigation feasible for excision of osteoid osteoma in the appendicular skeleton? - Retrospective analysis of 58 cases

Background

The use of intraoperative CT navigation to manage osteoid osteoma is not common. We report our experience managing osteoid osteoma in the appendicular skeleton using an intraoperative AIRO CT navigation system.

Materials & methods

Between May 2013 and December 2022, 59 patients underwent Navigation-assisted excision of osteoid osteoma in the appendicular skeleton. Our primary study outcome was to assess for recurrence of the tumour with recurrence of symptoms. For our secondary outcomes, we evaluated the complications associated with the procedure and evaluated the histological slides of all patients to see for the presence of nidus.

Results

Of the 58 patients available for review, no patient had a lesion recurrence, and all were symptom-free at an average follow-up of 45.6 months (6-100). Two patients (3.5%) had a superficial infection managed conservatively, and 43 patients (74.1%) had the presence of nidus in curetted samples. No patient developed a pathological fracture after the procedure.

Conclusion

Using intraoperative CT navigation to manage osteoid osteoma in the appendicular skeleton is safe, minimally invasive, and effective in completely removing the nidus with a negligible complication rate. The absence of nidus on histology should not be a concern to clinicians once thorough burring and verification of excision of nidus has been confirmed intra-operatively.

Study design

Retrospective Case Series.

Level of evidence

Level IV.

Intraoperative cone-beam computed tomography-guided curettage for osteoid osteoma

Recently, cone-beam computed tomography (CBCT)-guided surgeries have been developed for bone and soft tissue tumors. The present study aimed to evaluate the efficacy of CBCT-guided curettage for osteoid osteoma. Our study population included 13 patients who underwent primary curettage for osteoid osteoma using intraoperative CBCT in a hybrid operating room between April 2019 and November 2022. We collected the following data: sex, age, follow-up period, symptom onset to time of surgery, tumor size and location, length of skin incision, operating time, radiation dose, recurrence, postoperative complications, and visual analog scale for pain during the last follow-up. There were 10 male and 3 female patients, and the mean age was 25.0 years (range, 9-49 years). The mean follow-up period was 10.6 months (range, 0.4-24.0 months). The locations of the tumors were the proximal femur in 6 patients, the acetabular region in 2 patients, and the ilium, tibial shaft, calcaneus, cuboid, and talus in 1 patient each. The mean time of symptoms onset to surgery was 18.7 months (range, 2.3-69.9 months). The mean maximum diameter of the tumor was 5.9 mm (range, 3.5-10.0 mm). The mean length of the skin incision was 2.2 cm (range, 1.5-3.5 cm). The mean operating time was 96.9 minutes (range, 64-157 minutes). The mean dose of radiation was 193.2 mGy (range, 16.3-484.0 mGy). No recurrences, postoperative complications, and reoperation were observed in this study. All the patients reported 0 mm on the visual analogue scale for pain on the last follow-up. CBCT-guided curettage for osteoid osteoma was minimally invasive and reliable. This procedure can be effective for the treatment of lesions found in deep locations such as the pelvic bone and proximal femur or an invisible lesion that cannot be detected by regular fluoroscopy.

Efficacy and safety of magnetic resonance-guided focused ultrasound for the treatment of osteoid osteoma: A systematic review and meta-analysis

OBJECTIVE

Magnetic resonance-guided focused ultrasound (MRgFUS) is a novel noninvasive interventional technique for osteoid osteoma (OO). The purpose of this study was to evaluate the efficacy and safety of MRgFUS in the treatment of OO through a systematic review and meta-analysis of pain scores and post-treatment adverse events before and after MRgFUS treatment.

MATERIALS AND METHODS

A comprehensive literature search of PubMed, Embase, Web of science, and Cochrane Library databases was conducted to screen the study literature based on inclusion and exclusion criteria to extract and analyze pre- and post-treatment pain score data, success rates (complete pain relief with no recurrence until the last follow-up), recurrence rates, secondary intervention rates, and complications to evaluate the efficacy and/or safety of MRgFUS for OO.

RESULTS

A total of 113 studies published between 2012 and 2022were collected, resulting in a total sample size of 353 patients. The majority of the studies were prospective and had a follow-up period of 4 weeks or more, and overall, the quality of evidence ranged from low to high. Pain scores at 1 week and 1 month after the merger were 0.62 (9.5% CI:0.28-0.96) and 0.37 (9.5% CI:0.07-0.68), respectively. The success rate of the combination was 92.8% (95% CI: 89.8%-95.7%), the incidence of minor complications (thermal injury at the ablation site) was 0.85%, and no major complications were recorded in any of the included literature.

CONCLUSION

MRgFUS is an effective procedure that is able to treat pain for patients with OO with satisfying efficacy and safety.

PROSPERO

No.CRD42023415573.

Osteoid Osteoma, a Diagnostic Problem: A Series of Atypical and Mimicking Presentations and Review of the Recent Literature

Osteoid osteoma (OO) is a common benign bone tumour, usually affecting young people. Typically, it is localised to the diaphyses or metaphyses of long bones. The classical manifestation includes distinctive night pain, almost always present, responding well to non-steroidal anti-inflammatory drugs, sometimes accompanied by complaints due to physical activity, and a typical picture on additional tests. A characteristic of osteoid osteoma is the presence of a nidus, usually visible on imaging tests. The nidus generally presents as a single, round lytic lesion up to 1 cm in diameter, surrounded by an area of reactive ossification. However, OO is a multifaceted neoplasm, and its diagnosis can cause numerous difficulties. OO can mimic multiple diseases and vice versa, which often leads to a prolonged diagnostic and therapeutic path and associated complications. There are few literature reviews about the differentiation and diagnostic difficulties of osteoid osteoma. Very effective therapies for this tumour are known, such as ablation and resection. Enhanced detection of osteoid osteoma could result in faster diagnosis and less suffering for the patient, avoidance of complications, and reduced costs of incorrect and prolonged treatment.

Radiofrequency ablation is as safe and effective as surgical excision for spinal osteoid osteoma: a systematic review and meta-analysis

BACKGROUND

Osteoid osteoma (OO) is a primary benign tumor that affects mainly young patients. Ten percent of all OO are located in the vertebral column. Treatment of spinal OO is challenging and there is no consensus in the literature on the best operative approach.

PURPOSE

The aim of this systematic review and meta-analysis was to determine safety and efficacy of radiofrequency ablation (RFA) versus surgical excision for the treatment of spinal OO.

METHODS

A literature search was performed on PubMed, Web of Science, and Embase from inception up to 22 March 2022. Studies addressing surgical excision or RFA for the treatment of spinal OO were included. The main outcomes evaluated were pain before and after intervention, the treatments success rate, defined as complete pain relief with no recurrence until the last follow-up, and the number and type of complications.

RESULTS

Thirty-one studies (749 patients) were included. For patients who underwent surgical excision, 19 studies reported a mean treatment success rate of 85.6%, while in the RFA treatment group, 18 studies reported a mean success rate of 88.6%. At last follow-up, the pooled mean difference in pain scores from baseline on a 0-10 scale was 5.8 points in the surgical excision group and 6.7 points in the RFA group. Recurrences were observed in 5.6% of the patients who underwent surgical excision and in 6.7% of the patients treated with RFA. The complication rate was 7.8% in the surgical excision group and 4.4% in the RFA group.

CONCLUSIONS

This meta-analysis found high global success rates for both surgical and RFA treatments. Both treatments were efficient in pain relief and presented a low rate of recurrences. The complication rate was low for both treatments. Compared to surgical excision, RFA is a less invasive procedure which proved to be a safe and as effective option for the treatment of spinal OO.

The surgical management of osteoid osteoma: A systematic review

Background

Osteoid osteoma (OO) comprises approximately 11%-14% of benign bone tumors. The main symptom of OO is localized pain accompanied by nighttime aggravation. Surgical treatment is frequently used in clinic, including open surgery and percutaneous ablation, the latter including radiofrequency ablation, cryoablation, and microwave ablation, but there is no consensus on when and how to choose the best treatment for OO.

Purpose

We did a systematic review of the literature on existing surgical treatments of OO to assess the safety and efficacy of surgical treatments of OO and to evaluate the surgical options for different locations of OO.

Methods

The inclusion criteria in the literature are 1. Patients diagnosed with osteoid osteoma and treated surgically; 2. Include at least five patients; 3. Perioperative visual analogue scale (VAS), postoperative complications, and recurrence were recorded; 4. Literature available in PubMed from January 2014 to December 2021.

Results

In the cohort, 1565 patients (mainly adolescents) with OO received 1615 treatments. And there are 70 patients with postoperative recurrence and 93 patients with postoperative complications (minor: major=84:9). The results of Kruskal-Wallis examination of each experimental index in this experiment were clinical success rate H=14.818, p=0.002, postoperative short-term VAS score H=212.858, p<0.001, postoperative long-term VAS score H=122.290, p<0.001, complication rate H=102.799, p<0.001, recurrence rate H=17.655, p<0.001, the technical success rate was H=45.708, p<0.001, according to the test criteria of α=0.05, H0 was rejected. The overall means of the outcome index in each group were not completely equal.

Conclusion

Percutaneous ablation and open surgery are safe and reliable for OOs, and the technical success rate of percutaneous ablation is higher than that of open surgery. Open surgery and cryoablation can be selected for OOs close to the nerve and atypical sites, while radiofrequency ablation and microwave ablation can be selected for OOs in most other sites.

Intra- and juxta-articular osteoid osteoma in children and adolescents

BACKGROUND

Osteoid osteoma (OO) is a common benign tumor in children and adolescents, but intra-and juxta-articular OO is rare and difficult to diagnose. The purpose of this study is to investigate the distinctions between intra- and juxta-articular OO, trying to avoid delaying diagnosis and optimize treatment strategies.

METHODS

Thirty patients diagnosed with OO in the intra- and juxta joint at our institution who underwent surgical resection were included. Clinical and epidemiological factors, preoperative radiograph parameters, including computed tomography (CT), magnetic resonance imaging (MRI), and bone scan, were documented. The outcomes of the involved extremity were evaluated at the final follow-up.

RESULTS

Mean age at diagnosis, interval time, and follow-up time was 8.37±3.79 years old, 4.67±5.88 months, 3.57±2.18 years, respectively. Factors identified to be significantly associated with intra- and juxta-articular OO including pain with activity (P=0.004) and abnormal range of motion (P=0.00). The factor of abnormal range of motion (P=0.03) also influenced the existence of complications. Six children had a secondary operation to cure the recurrence.

CONCLUSIONS

It is essential for clinicians and radiologists to be aware of the atypical clinical and radiographic features of intra- and juxta-articular OO, as the delayed diagnosis can lead to unnecessary pain and further complications after surgeries. The pain with activity and abnormal range of motion is helpful to identify the location of OO. The persistently abnormal range of motion also significantly leads to complications. The open surgeries to resect the nidus in juxta-articular OO were effective.

Post-Procedural Follow-Up of the Interventional Radiology’s Management of Osteoid Osteomas and Osteoblastomas

The family of painful osteocytic tumors includes osteoblastomas and osteoid osteomas—these lesions are considered benign, but they could produce a significant painful symptomatology. Usually, people affected are between 20 s and 30 s. When symptomatic, an effective treatment is mandatory for the management of these lesions to allow for a ful quality of life. The possibilities of treatment range from chirurgical en-block resection (procedure of surgical oncology aiming to remove a tumoral mass in its entirety, completely surrounded by a continuous layer of healthy tissue) to interventional approaches that, nowadays, are considered the most affordable and sustainable in terms of effectiveness, recovery after procedure, and for bone structure sparing. The main techniques used for osteoid osteomas and osteoblastomas are radio frequency ablation (RFA) and magnetic resonance-guided focused ultrasound (MRgFUS): the most important difference between these approaches is the needleless approach of MRgFUS, which further reduces the minimal invasiveness of RFA (and the related consequences) and the absence of exposure to ionizing radiation. Despite their high efficacy, a recurrence of pathology may occur due to a failure in therapy. In light of this, describing the various possibilities of follow up protocols and the imaging aspects of recurrence or incomplete treatment is mandatory. In the scenario given in the literature, many authors have tried to asses an organized follow up protocol of these patients, but many of them did not undergo periodical magnetic resonance (MR) or computerized tomography (CT) because of the lack of symptomatology. However, even if it seems that clinical evolution is central, different papers describe the protocol useful to detect eventual relapse. The aim of our manuscript is to review the various possibilities of follow-up of these patients and to bring together the most salient aspects found during the management of these osteocytic bone lesions.

Needleless Ablation of Osteoid Osteoma and Osteoblastoma: The Emergent Role of MRgFUS

Osteoblastoma (OB) and osteoid osteoma (OO) are benign bone-forming tumors, with nearly identical basic microscopic features. The main difference is dimension (OO has usually a nidus measuring <2 cm in diameter). In addition, OB is biologically more active than OO, with a tendency to grow in size. Historically, treatments have included surgical resection and analgesics, although invasiveness and poor tolerance have led to the current standard of care moving toward interventional radiology, where radiofrequency ablation (RFA) represents the most diffuse technique. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) has recently emerged as another innovative alternative treatment, providing tumor ablation through a needleless and ionizing radiation-free modality. In addition, this technique has the ability to guarantee a very precise and controlled increase in temperature, delivering small amounts of energy that can accurately destroy only the lesion, avoiding healthy surrounding tissues. The present review focuses on MRgFUS as the less invasive, safe, effective, and durable treatment option for the management of osteoid osteoma and osteoblastoma, including a description of technical details, indications and outcomes.

A Rare Presentation of Osteoid Osteoma in a 77-Year-Old Patient, Treated with Computer Tomography-Guided Percutaneous Radiofrequency Ablation

Osteoid osteoma (OO) is a benign bone forming tumor characterized by small size and a disproportionate amount of pain. They are most commonly seen between the ages of 5 and 30 years; however, they can be seen in the older patient albeit infrequently. The hands and feet are the least common site of OO among the extremity bones. We present a case of an OO in the hand of a 77-year-old man who underwent successful treatment with computed tomography–guided percutaneous radiofrequency ablation. We believe this is the oldest recorded patient in the medical literature with a histologically confirmed OO. The condition should therefore be considered in the differential diagnosis of a painful sclerotic bone lesion in this age group to avoid a delay in diagnosis and subsequent treatment.

Femur Neck Osteoid Osteoma Managed with Radiofrequency Ablation - A Case Report

Introduction

Osteoid osteoma is a benign tumor of bones involving mainly the tubular bones and rarely axial skeletons. The patient mainly complains of night pain in the affected region or the joint nearby. Pain always subsides with analgesics and gradually increased over the period of time. It is mostly missed on the plain radiograph so magnetic resonance imaging or computed tomography (CT) scan are preferred for accurate and early diagnosis of the tumor.

Case Report

A 20-year-old male presented with pain in the left hip region which was gradually increased over the period of 6 months and was experiencing pain more in the night, used to relieve on medications. CT scan of the left hip showed the presence of osteoid osteoma of 0.5 cm diameter, which was managed with radiofrequency ablation. Moreover, the patient had pain relief immediately after the procedure. At present 1-year follow-up, the patient is symptomless with no recurrence.

Conclusion

The neck of femur osteoid osteomas is best managed with radiofrequency ablation as it causes less morbidity to the patient and helps in early return to normal activities with fewer complications as compared to open procedures.

Effects of control temperature, ablation time, and background tissue in radiofrequency ablation of osteoid osteoma: A computer modeling study

To study the effects of the control temperature, ablation time, and the background tissue surrounding the tumor on the size of the ablation zone on radiofrequency ablation (RFA) of osteoid osteoma (OO). Finite element models of non-cooled temperature-controlled RFA of typical OOs were developed to determine the resulting ablation radius at control temperatures of 70, 80, and 90°C. Three different geometries were used, mimicking common cases of OO. The ablation radius was obtained by using the Arrhenius equation to determine cell viability. Ablation radii were larger for higher temperatures and also increased with time. All geometries and control temperatures tested had ablation radii larger than the tumor. The ablation radius developed rapidly in the first few minutes for all geometries and control temperatures tested, developing slowly towards the end of the ablation. Resistive heating and the temperature distribution showed differences depending on background tissue properties, resulting in differences in the ablation radius on each geometry. The ablation radius has a clear dependency not only on the properties of the tumor but also on the background tissue. Lower background tissue's electrical conductivity and blood perfusion rates seem to result in larger ablation zones. The differences observed between the different geometries suggest the need for patient-specific planning, as the anatomical variations could cause significantly different outcomes where models like the one here presented could help to guarantee safe and successful tumor ablations.

CT-guided percutaneous radiofrequency ablation of osteoid osteoma: Our experience in 87 patients

Purpose:

To evaluate the technical and clinical success of radiofrequency ablation of osteoid osteoma and analyze the factors responsible for clinical success. We also tried to investigate the role of follow-up computed tomography (CT) imaging.

Materials and Methods:

This is a prospective study approved by the institute's ethics committee involving 87 patients with appendicular osteoid osteoma. CT-guided radio frequency ablation was performed using a bipolar ablation system. Patients were followed up over 15.4 (4–24) months for pain, and clinical success/failure was determined using established criteria. Patients with clinical failure were taken for repeat ablation. Follow-up CT was obtained at 6 months and correlated with clinical success. Procedural scans were later reviewed for technical success in a blinded manner and correlated with clinical success along with other imaging and patient characteristics.

Results:

Mean pre-procedure visual analog scale (VAS) score was 7.0 ± 0.8. Primary success rate after single session was 86.2%(75/87 patients), and overall success rate after one/two sessions was 96.6%(84/87). No major complications were noted. Technical success rate was 89.7%(78/87). All 9 patients who had a suboptimal needle positioning had recurrence where as three patients had recurrence despite technical success. None of the imaging characteristics or history of prior intervention was significantly associated with clinical success. Follow-up CT showed advanced bone healing in 48 lesions, and was confined to the treatment success group. Alternately, minimal/absent bone healing was seen in all (12) patients of primary treatment failure and 27 patients with treatment success.

Conclusions:

CT-guided percutaneous radio frequency ablation is a safe and highly effective treatment for osteoid osteomas even in recurrent and residual cases. Technical success is the most important parameter affecting the outcome. Post radio frequency ablation CT findings have a good positive but a poor negative predictive value in prognostication.

Hip arthroscopy has good clinical outcomes in the treatment of osteoid osteoma of the acetabulum

BACKGROUND

Osteoid osteoma (OO) of the acetabulum is a relatively rare disease. However, the the clinical outcomes of hip arthroscopy for treatment of OO of the acetabulum are still uncertain.

METHODS

We evaluated consecutive patients who were diagnosed with OO of the acetabulum and who underwent hip arthroscopy at our hospital between January 2013 and March 2020. All patients underwent a preoperative physical examination. Preoperative supine anteroposterior hip radiography, cross-table lateral radiographs, computed tomography (CT), and magnetic resonance imaging were performed in all patients. The alpha angle and lateral center-edge angle were measured before surgery. Supine anteroposterior hip radiography and CT were performed in all patients postoperatively. Preoperative patient-reported outcomes (PROs), including Visual Analog Scale (VAS), the International Hip Outcome Tool-12 (iHOT-12) and modified Harris Hip Score (mHHS), and PROs at final follow-up were evaluated.

RESULTS

A total of 6 patients (mean age, 18.7 years; age range, 6-31 years; 5 males and 1 females) were included in this study. The average follow-up period after surgery was 28.3 months (range, 6-90 months). Before surgery, the mean mHHS was 45.2 ± 10.5 (range, 33-56), the mean iHOT-12 was 33.3 ± 14.5 (range, 13-49), and mean VAS was 8.2 ± 1.0 (range, 7-9). At one month after surgery, mean mHHS was 78.7 ± 1.9 (range, 77-81), iHOT-12 was 71.0 ± 4.5 (range, 68-80), and mean VAS was 0. At the final post-operative follow-up, mean mHHS was 89.2 ± 2.1 (range, 86-91), iHOT-12 was 93.5 ± 5.0 (range, 88-98), and mean VAS was 0. All results, except VAS between one month after surgery and at final follow-up, demonstrated statistically significant improvement (P < 0.05). One patient underwent revision surgery.

CONCLUSIONS

Hip arthroscopy has good clinical outcomes in the treatment of OO of the acetabulum. Further study on the mechanism of secondary femoroacetabular impingement (FAI) caused by OO of the acetabulum is needed. More cases of arthroscopic excision and longer follow-up are also needed to better prove the clinical outcomes of hip arthroscopy for OO of the acetabulum.

Osteoid osteoma: which is the best mininvasive treatment option?

Osteoid osteoma is the third most common benign bone tumor, with well-known clinical presentation and radiological features. Although surgical excision has been the only therapeutic option for a long time, to date it has been replaced by minimally invasive techniques, which proved satisfactory success rates and low complication occurrence. Therefore, the purpose of this literature review was to describe the main updates of these recent procedures in the field of interventional radiology, with particular attention paid to the results of the leading studies relating to the efficacy, complications, and recurrence rate. Nevertheless, this study aimed to analyze the peculiarities of each reported technique, with specific focus on the possible improvements and pitfalls. Results proved that all mininvasive procedures boast a high success rate with slight number of complications and a low recurrence rate. Radiofrequency ablation is still considered the gold standard procedure for percutaneous treatment of osteoid osteoma, and it has the possibility to combine treatment with a biopsy. Interstitial laser ablation's advantages are the simplicity of use and a lower cost of the electrodes, while cryoablation allows real-time visualization of the ablated zone, increasing the treatment safety. Magnetic resonance-guided focused ultrasound surgery is the most innovative non-invasive procedure, with the unquestionable advantage to be radiation free.

Computed tomography-guided percutaneous radiofrequency and laser ablation for the treatment of osteoid osteoma - long-term follow-up from 5 to 10 years

Purpose

The impact of computed tomography (CT)-guided, percutaneous radiofrequency ablation and interstitial laser ablation (ILA) on the management of patients with osteoid osteoma was studied. This was carried out by assessing immediate and long-term clinical outcomes, the complication rate, and repeat therapy effectiveness in recurrent patients who have already experienced percutaneous ablation.

Material and methods

Consecutive patients with osteoid osteoma were assessed before the interventional treatment in a single centre from 2010 to 2015. Patient demographics, complications, and recurrence were recorded. The pain was evaluated with Visual Analogue Scale (VAS). Percutaneous procedures were performed by means of radiofrequency thermoablation or ILA. Epidural or regional anaesthesia in the CT suite was applied in all procedures. Success, whether primary or secondary, was measured as complete pain relief without evidence of recurrence after the first or second procedure, respectively. Osteoid osteoma characteristics, procedure overview, and technical success were looked for in pre-procedural and procedural scans.

Results

Eighty-three per cent of osteoid osteomas were located in lower extremities, 56% of tumours were intracortical, and 83% of osteoid osteomas were extra-articular. The mean pre-procedure VAS score was 8.5 ± 0.8, while the overall primary success rate of radiofrequency thermoablation and ILA was 87.5%. No major complications were noted. The mean follow-up period for patients in was 7.5 years (5.0-10.2 years).

Conclusions

Percutaneous, CT-guided thermoablation proved to be effective and should become the method of choice in osteoid osteoma treatment because of its minimal invasiveness. Our results show that there is no risk of very late recurrence after achieving primary and secondary treatment success.

Osteoid osteoma: the great mimicker

Osteoid osteoma is a painful, benign and common bone tumor that is prevalent in young adults. The typical clinical presentation consists of pain that becomes worse at night and is relieved by nonsteroidal anti-inflammatory drugs. The most common imaging finding is a lytic lesion, known as a nidus, with variable intralesional mineralization, accompanied by bone sclerosis, cortical thickening and surrounding bone marrow edema, as well as marked enhancement with intravenous contrast injection. When the lesion is located in typical locations (intracortical bone and the diaphyses of long bones), both characteristic clinical and radiological features are diagnostic. However, osteoid osteoma is a multifaceted pathology that can have unusual presentations, such as intraarticular osteoid osteoma, epiphyseal location, lesions at the extremities and multicentric nidi, and frequently present atypical clinical and radiological manifestations. In addition, many conditions may mimic osteoid osteoma and vice versa, leading to misdiagnosis. Therefore, it is essential to understand these musculoskeletal diseases and their imaging findings to increase diagnostic accuracy, enable early treatment and prevent poor prognosis.

Effectiveness and reliability of traditional open surgery in atypical localizations of osteoid osteoma

Objectives

This study aims to evaluate traditional open surgery results of osteoid osteomas (OOs) in atypical localizations and explore whether open surgery can be a safe alternative in localizations where radiofrequency ablation (RFA) may not be suitable.

Patients and methods

A total of 26 patients (20 males, 6 females; mean age 23.3±14.2 years; range, 4 to 65 years) having OO in atypical localizations between January 2008 and January 2017 were retrospectively evaluated. All patients underwent traditional open surgery under anesthesia. All patients were followed-up, and their clinical success and complications were evaluated. The pain intensity was assessed using the visual analog scale (VAS).

Results

The postoperative first year VAS score was 0.2±0.5 (range, 0-2) (p<0.005). None of the patients showed any complications. No recurrences were reported at the end of the first year. All patients were relieved from pain due to OO in atypical localizations.

Conclusion

Although RFA has been accepted as the preferred treatment for OO, traditional open surgery may still be used for OO in atypical localizations yielding perfect clinical results with fewer complications. It is a safe alternative for localizations such as carpal bones, distal ulna, hand and foot where RFA complications can be seen more frequently. In these localizations, traditional open surgery can be recommended as the first treatment choice.

Computed Tomography-Guided Radiofrequency Ablation of Osteoid Osteoma in Atypical Sites: Efficacy and Safety in a Large Case Series

RATIONALE AND OBJECTIVES

Although computed tomography (CT) guided radiofrequency ablation (RFA) is accepted as the gold standard treatment for osteoid osteoma (OO) in extremities, most researchers have omitted OO in critical sites. We aimed to evaluate the efficacy and safety of CT-guided RFA in the management of OO in atypical sites.

MATERIALS AND METHODS

A prospective interventional study conducted on 34 patients (12 women and 22 men; mean age, 22.3 ± 3.5 years; range, 12-48 years) with OO in atypical sites. All patients were treated with CT-guided RFA. All procedures were performed under general anesthesia using a single straight, rigid RF electrode for 6 minutes at 90°C. All patients were followed up; technical and clinical successes of treatment were evaluated. The severity of pain was assessed on a visual analogue scale (VAS).

RESULTS

CT-guided RFA was performed in all patients with 100% technical success and 100% primary clinical success. All patients had complete pain relief and returned to their quality of life without further analgesics within 1 month after the procedure. All procedures were successfully completed without any major complications. The mean preprocedure VAS score dropped to zero by the end of the first week with a highly statistically significant difference (p < 0.001).

CONCLUSION

CT-guided RFA is a safe and effective procedure in the management of OO in atypical sites with 100% primary success rate, 0% long-term recurrence rate, and very low complication rate.

CT-guided radiofrequency ablation for osteoid osteomas: a systematic review

OBJECTIVES

CT-guided radiofrequency ablation (CT-RFA) is considered to be the gold standard for treatment of osteoid osteoma (OO) yet treatment failures (TFs) continue to be reported. This systematic review was conducted to evaluate factors associated with TF, such as ablation time, lesion location, and patient age as well as evaluating how TF has trended over time.

METHODS

Original studies reporting on patients undergoing CT-RFA of OO published between 2002 and 2019 were identified. TF was defined as patients with (1) recurrent or persistent pain +/- (2) imaging evidence of persistent OO. TFs were subdivided into those occurring after the index procedure (primary TF) or those occurring after repeat RFA (secondary TF). Subgroup analysis was performed for TF based on the study date (2002-2010 or 2010-2019), time duration of ablation at 90 °C (6 min or > 6 min), patient age, and tumor location (spinal vs. appendicular).

RESULTS

Sixty-nine studies were included for a total of 3023 patients. The global primary TF rate was 8.3% whereas the secondary TF rate was 3.1%. The TF rate reported in studies published after 2011(7%) was about half that during the earlier time period 2002-2010 (14%). There was no statistical difference in TF corrected for age, OO location, or duration of ablation (respectively p = 0.39, 0.13, and 0.23). The global complication rate was 3%, the most frequent being skin burns (n = 24; 0.7%).

CONCLUSIONS

A decrease in TF observed between 2011-2019 compared to 2002-2010 may reflect improvements in operator technique or advancements in equipment. Duration of ablation, patient age, or location of OO failed to significantly correlate with TF.

KEY POINTS

• CT-guided radiofrequency ablation of osteoid osteomas is a safe technique with a low rate of treatment failure (8.3% failure rate after the primary radiofrequency reducing to 3.1% following a secondary treatment). • The treatment failure rate has decreased over time, possibly due to an improved understanding of the disease process, better technique, and advances in equipment. • Duration of ablation, patient age, or lesion location did not significantly correlate with treatment failure.

Percutaneous thermal ablation for treatment of osteoid osteoma: a systematic review and analysis

OBJECTIVE

Although radiofrequency ablation is well validated for treatment of osteoid osteoma, newer technologies, namely cryoablation, have been less thoroughly studied. The purpose is to perform a systematic review and pooled analysis of percutaneous ablation technologies for treatment of osteoid osteoma with subset analysis of intra-articular and spinal tumors.

MATERIAL AND METHODS

A total of 36 of 79 identified manuscripts met inclusion criteria, comprising 1863 ablations in 1798 patients. Inclusion criteria were (1) retrospective or prospective analysis of thermal ablation of osteoid osteomas in any location, (2) at least 6 months of clinical follow-up, (3) 10 or more patients, (4) patients not included in a second study included in this review, and (5) English language or English translation available. Success rate was defined as all ablations minus technical failures, clinical failures, and recurrences. Subset analysis of intra-articular and spinal tumors was performed.

RESULTS

Overall success rate was 91.9% (95% CI 91-93%). Technical failure, clinical failure, and recurrence rates were 0.3%, 2.1%, and 5.6% respectively. Complications were seen in 2.5% (95% CI 1.9-3.3%) patients. There was no significant difference when comparing radiofrequency ablation and cryoablation (p = 0.92). Success rates for intra-articular (radiofrequency ablation) and spinal tumors (radiofrequency and cryoablation) were 97% and 91.6% respectively.

CONCLUSION

Percutaneous ablation of osteoid osteomas was highly successful with low complication rates. Efficacy of radiofrequency ablation and cryoablation is similar, which is consequential because cryoablation is associated with decreased pain, predictable nerve regeneration, and theoretical immunotherapy benefits. Treatment of more challenging intra-articular and spinal lesions demonstrated similarly high success and low complication rates.

A case report of an unrecognized osteoid osteoma of the proximal femur

We present the case of a 59-year-old male patient with unrecognized osteoid osteoma in radiography as well as in magnetic resonance imaging. Computed tomography revealed osteoid osteoma that was successfully treated with percutaneous computed tomography guided radiofrequency ablation. The osseous pathology was underestimated on magnetic resonance imaging in the presented case and bone marrow edema led to incorrect diagnosis. The particular case emphasizes the value of computed tomography scans diagnosing an osteoid osteoma.

Evolution of the imaging features of osteoid osteoma treated with RFA or MRgFUS during a long-term follow-up: a pictorial review with clinical correlations

Interventional radiology is today considered the first-line treatment for osteoid osteoma both in the form of needle-guided technique of ablation (Radiofrequency) and of needleless technique (magnetic resonance-guided focused ultrasound surgery). The follow-up study of the procedures is mainly clinical, since the disappearance of pain is consistent with the success of the procedure. However, due to the minimally invasive and innovative nature of the approach, interpretation of the follow-up imaging could be ambiguous and misleading. Aim of our review was to define the main findings on the imaging that can best describe the regular evolution of these types of treatment. In particular, four findings were considered: (1) bone marrow oedema; (2) reactive phenomena (perilesional inflammatory reaction for extra-articular lesions or synovial reaction for intra-articular lesions); (3) bone remodelling (disappearance of the nidus and bone healing); (4) ring sign (considered as the granulation tissue around the nidus treated). These findings were evaluated using MRI and CT with a follow-up study that lasted up to 24 months.

Emerging hyperthermia applications for pediatric oncology

Local application of hyperthermia has a myriad of effects on the tumor microenvironment as well as the host's immune system. Ablative hyperthermia (typically > 55 °C) has been used both as monotherapy and adjuvant therapy, while mild hyperthermia treatment (39-45 °C) demonstrated efficacy as an adjuvant therapy through enhancement of both chemotherapy and radiation therapy. Clinical integration of hyperthermia has especially great potential in pediatric oncology, where current chemotherapy regimens have reached maximum tolerability and the young age of patients implies significant risks of late effects related to therapy. Furthermore, activation of both local and systemic immune response by hyperthermia suggests that hyperthermia treatments could be used to enhance the anticancer effects of immunotherapy. This review summarizes the state of current applications of hyperthermia in pediatric oncology and discusses the use of hyperthermia in the context of other available treatments and promising pre-clinical research.

Treatment-related alterations of imaging findings in osteoid osteoma after percutaneous radiofrequency ablation

OBJECTIVES

We aimed to report the long-term outcomes of osteoid osteoma patients and to determine CT and dynamic contrast-enhanced MR imaging characteristics of radiofrequency ablation (RFA) treatment related changes of osteoid osteoma between follow-up periods.

MATERIALS AND METHODS

Thirty patients (seven female, 23 male) who underwent CT-guided RFA of osteoid osteoma were included. Follow-up imaging examinations were divided into two subgroups; first (1-3 months) and second (> 6 months) periods. Nidus size, calcification, cortical thickening, maximum signal intensity (SImax), time of SImax (Tmax), slope of signal intensity-time (SIT) curves were noted. CT and dynamic MR imaging findings were compared between follow-up periods.

RESULTS

Clinical success rate was 100%. The mean of OO nidi size was 5.85 ± 1.98 mm before treatment. There was a significant difference for OO nidi sizes between pretreatment and second follow-up period examinations (p = 0.002). SImax and slope of SIT curves of all patients (100%) showed decrease on follow-up MRIs. There was a significant decrease for SImax values between pretreatment and second follow-up period. There was a significant decrease for slope of SIT curves between pretreatment and both follow-up periods.

CONCLUSIONS

RFA is an effective and safe treatment choice for osteoid osteomas. On follow-up imaging, slope of SIT curve and Tmax have the most important positive predictive value for long-term outcomes and single dynamic contrast-enhanced MRI within first 3 months after treatment may be sufficient for symptom-free patients.

[Analysis of the quality of life of patients with osteoid osteoma before and after radiofrequency ablation treatment]

BACKGROUND

The aim of this study was to investigate the effectiveness of the treatment of osteoid osteomas (OO) by radiofrequency ablation (RFA). In particular, the recurrence rate and the improvement in the quality of life as assessed by the reduction of pain intensity were evaluated.

METHODS

Retrospective analysis of 26 patients after RFA of an OO and prospective analysis of 14 patients using a self-developed quality of life questionnaire. The questionnaire, the electronic patient file and the histopathological findings were processed.

RESULTS

An average of 22 months passed between the first onset of complaints and the causative treatment by RFA. After RFA, there was a significant reduction in pain symptoms and thus an increase in the quality of life. These results confirm that RFA from OO is a safe and efficient treatment procedure.

DISCUSSION

In order to avoid long-term conservative treatment attempts and to reduce effects on the musculoskeletal system, a timely RFA of OO should be performed after diagnosis.

Safe and Effective Treatment Choice for Osteoid Osteoma: Computed Tomography-guided Percutaneous Radiofrequency Ablation

Introduction

Osteoid osteoma (OO) is a painful, benign, bone-forming tumor characterized by a small central nidus surrounded by sclerotic tissue. The aim of the present study was to evaluate the clinical outcome after computed tomography (CT)-guided radiofrequency ablation (RFA) in patients with OO performed from January 2012 to June 2018 and to confirm the safety and efficacy of CT-guided RFA.

Methods

Between January 2012 and June 2018, a total of 63 patients were treated with CT-guided RFA. Pre- and post-treatment pain, further treatment after the RFA procedure, observed complications, and satisfaction with the treatment were recorded for an assessment of clinical effects in all patients. The patients were evaluated with the visual analog scale (VAS) pre-procedure and at three months post-procedure.

Results

Of the patients, 39 were males and 24 were females with a mean age of 21 ± 9.7 (range, 9 to 41) years. The mean follow-up was 16 ± 2.1 (range, 12 to 19) months. The mean duration of the procedure was 34 ± 11.4 (range, 22 to 47) min. All of the patients were diagnosed with OO pathologically. A statistically significant difference was found between the pre-procedural and post-procedural VAS scores (p<0.001). Complications were observed in six patients including one peroneal nerve lesion, three minor skin burns, and two minor skin infections.

Conclusion

This study shows that CT-guided RFA is a safe and effective treatment for OO. It is thought that RFA could be the primary treatment choice for most OO with typical symptoms and radiological findings.

Osteoid Osteoma About the Hip in Children and Adolescents

BACKGROUND

The etiology of hip pain in pediatric and adolescent patients can be unclear. Osteoid osteoma (OO) about the hip in children has only been described in case reports or small studies. The present study assessed the clinical presentation and diagnostic course, imaging, and treatment approaches in a large cohort of pediatric cases of OO about the hip.

METHODS

Medical record and imaging results were reviewed for all cases of OO identified within or around the hip joint in patients <20 years old between January 1, 2003, and December 31, 2015, at a tertiary-care pediatric center. Demographic, clinical, and radiographic data were analyzed.

RESULTS

Fifty children and adolescents (52% female; mean age, 12.4 years; age range, 3 to 19 years) were identified. Night pain (90%) and symptom relief with nonsteroidal anti-inflammatory drugs (NSAIDs) (88%) were common clinical findings. Sclerosis/cortical thickening was visible in 58% of radiographs, although a radiolucent nidus was visible in only 42%. Diagnostic imaging findings included perilesional edema and a radiolucent nidus on 100% of available magnetic resonance imaging (MRI) and computed tomography (CT) scans, respectively. Initial alternative diagnoses were given in 23 cases (46%), the most common of which was femoroacetabular impingement (FAI). Delay in diagnosis of >6 months occurred in 43% of patients. Three patients underwent operative procedures for other hip diagnoses, but all had persistent postoperative pain until the OO was treated. Of the 41 patients (82%) who ultimately underwent radiofrequency ablation (RFA), 38 (93%) achieved complete post-RFA symptom resolution.

CONCLUSIONS

Initial misdiagnosis, the most common of which was FAI, and delayed correct diagnosis are common in pediatric OO about the hip. Presenting complaints were variable and nonspecific MRI findings were frequent. Night pain and relief with NSAIDs were present in the vast majority of cases. CT scans provided definitive diagnosis in all patients who received them. As increasing numbers of young, active patients are being evaluated for various causes of hip pain, such as FAI, OO should not be overlooked in the differential diagnosis.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mini-open excision of osteoid osteoma using intraoperative O-arm/Stealth navigation

BACKGROUND

Although osteoid osteomas have traditionally been treated by surgical excision, radiofrequency ablation (RFA) has gained favor as a less invasive procedure. However, RFA is contraindicated for osteoid osteomas close to the skin or crucial neurovascular structures, and is not covered by national health insurance in Japan. The aim of the present study was to evaluate the efficacy of surgical excision of osteoid osteomas using intraoperative navigation.

METHODS

We performed a retrospective review of five patients with osteoid osteoma who underwent a mini-open excision using O-arm/Stealth navigation at our institution. The osteoid osteomas were excised using a cannulated cutter or curetted out with the assistance of navigation.

RESULTS

Complete excision was achieved in all patients, which was confirmed by pathological examination. The mean skin incision was 2.1 cm (range, 1.5 to 3.0 cm) and the mean duration required for setup three-dimensional image was 15 min (range, 12 to 20 min). Although the mean visual analog scale score was 7 (range, 4 to 8) before surgery, all patients experienced relief from their characteristic pain immediately after surgery, with the mean scores of 2.2 (range, 1 to 3) and 0 at 2 days and 4 weeks after surgery, respectively. There was no intra-operative complication related to the navigation and no recurrence was observed during the mean follow-up period of 25 months (range, 13 to 33 months).

CONCLUSIONS

Mini-open excision using intraoperative O-arm/Stealth navigation is a safe and accurate procedure for patients with osteoid osteoma, which could cover the limitation of RFA.

Percutaneous Treatments of Benign Bone Tumors

Benign bone tumors consist of a wide variety of neoplasms that do not metastasize but can still cause local complications. Historical management of these tumors has included surgical treatment for lesion resection and possible mechanical stabilization. Initial percutaneous ablation techniques were described for osteoid osteoma management. The successful experience from these resulted in further percutaneous image-guided techniques being attempted, and in other benign bone tumor types. In this article, we present the most common benign bone tumors and describe the available results for the percutaneous treatment of these lesions.

Osteoid osteoma: Contemporary management

Osteoid osteoma is a benign bone-forming tumor with hallmark of tumor cells directly forming mature bone. Osteoid osteoma accounts for around 5% of all bone tumors and 11% of benign bone tumors with a male predilection. It occurs predominantly in long bones of the appendicular skeleton. According to Musculoskeletal Tumor Society staging system for benign tumors, osteoid osteoma is a stage-2 lesion. It is classified based on location as cortical, cancellous, or subperiosteal. Nocturnal pain is the most common symptom that usually responds to salicyclates and non-steroidal anti-inflammatory medications. CT is the modality of choice not only for diagnosis but also for specifying location of the lesion, i.e. cortical vs sub periosteal or medullary. Non-operative treatment can be considered as an option since the natural history of osteoid osteoma is that of spontaneous healing. Surgical treatment is an option for patients with severe pain and those not responding to NSAIDs. Available surgical procedures include radiofrequency (RF) ablation, CT-guided percutaneous excision and en bloc resection.

Phase I clinical trial of percutaneous cryoablation for osteoid osteoma

PURPOSE

This prospective phase I trial was conducted to evaluate the safety of percutaneous cryoablation for osteoid osteoma (OO).

MATERIALS AND METHODS

Nine patients with OO (mean tumor size: 5.9 mm; tibia, n = 5; femur, n = 2; lumbar spine, n = 2) were enrolled and treated with percutaneous cryoablation. The primary endpoint was the evaluation of the treatment safety as determined using step-by-step registration. The secondary endpoints were the incidence and grade of adverse events by CTCAE version 4.0, and the short-term efficacy of this treatment. Based on a decrease in the numerical rating scale (NRS) score, efficacy was classified as significantly effective (SE ≥ 5 or reached 0-2), moderately effective (ME 2-4), or not effective (NE < 2 or increase).

RESULTS

Cryoablation procedures were completed in all patients. Major adverse events (≥ grade 3) related to the procedure were not observed. Minor adverse events (≤ grade2) were observed in 22-67%. The mean NRS score was 7 before treatment, 0.6 at 4-week, 0.1 at 6-month, and 0 at 1-year post-treatment. All procedures were classified as SE.

CONCLUSION

Percutaneous cryoablation is a safe treatment for OO. Future phase II trials with large patient cohorts are warranted.

Radiofrequency ablation of osteoid osteoma in the atlas: A case report

Osteoid osteoma of the atlas has previously been reported very rarely in the published literature. The traditional standard treatment has been a surgical resection of the nidus. Recently, computed tomography (CT)-guided radiofrequency ablation (RFA) has gained favor as a more precise alternative treatment. Here, we present a case of osteoid osteoma of the C1 lateral mass treated successfully using CT-guided RFA. A 30-year-old woman who presented with a four-month history of occipital and suboccipital pain was treated by CT-guided RFA. The visual analog scale (VAS) assessed the pain before and after RFA. The patient reported significant pain relief and normal activities. The VAS score reduced from 8/7 to 1/0 after the procedure. Therefore CT-guided percutaneous RFA of C1 vertebral osteoid osteoma is a safe and effective method. The technique might be contraindicated when the nidus is less than 2 mm away from the neural structures.

Spinal osteoid osteoma: efficacy and safety of radiofrequency ablation

OBJECTIVE

The aim of this study was to evaluate the efficacy and complications of CT-guided radiofrequency ablation (RFA) of spinal osteoid osteoma (OO).

MATERIALS AND METHODS

Between 2002 and 2012, a total of 61 patients (46 male and 15 female, mean age 26.4 ± 12.7 years) were subjected to RFA for spinal OO. The diagnosis of OO was made after a period of pain and symptoms of 20.6 ± 14.4 months. RFA was performed under conscious sedation and local analgesia. Clinical symptoms were evaluated at 3, 6, and12 months, and at the end of the time of the present investigation. Mean follow-up was 41.5 ± 7.1 months.

RESULTS

The primary efficacy of RFA, complete regression of symptoms, was obtained in 57 out of 61 patients (93.4%). Four out of 61 (6.5%) patients showed a relapse of OO (after 3 months); 2 out of 4 were subjected to a second RFA, the remaining ones were subjected to surgery. There was one complication (case of lower limb paresthesia for 30 days after the ablation) and one possible complication (a disc herniation).

CONCLUSION

CT-guided RFA is an excellent treatment for spinal OO. Our data suggest that this procedure should be considered for the first stage of therapy for this disease.

Surgical resection of osteoid osteoma and osteoblastoma of the spine

Intraoperative radiographic guidance has traditionally been utilized in orthopedic surgery through 2-D navigation with the C-arm and recently with 3-D navigation with the O-arm. The aim of this study was to describe the outcome of surgical treatment of spinal osteoblastoma and osteoid osteoma with the utilization of the O-arm and conventional C-arm guidance. This is a retrospective cohort study of patients with spinal osteoid osteoma and or osteoblastoma who were treated at our institution between 2002 and 2011. Seventeen patients were examined in this study including seven with spinal osteoblastoma and 10 with spinal osteoid osteoma. The mean age of the patients at surgery was 11.5±3.9 years. The O-arm was used in seven patients and the C-arm in 10 patients. The C-arm failed to identify the tumor in one case and needed transport to perform a computed tomographic-scan. The length of surgery was shorter when the O-arm was used, especially in the osteoblastoma group. Thirteen patients were pain free at the last follow-up visit and two patients developed recurrence. Radiographs at the last follow-up did not show signs of vertebral instability following tumor resection. Safe and effective localization of spine tumors and confirmation of tumor removal during surgery was achieved by intraoperative radiographic guidance specifically with the O-arm 3-D navigation system.

LEVEL OF EVIDENCE

III.

Therapeutic outcome of CT-guided radiofrequency ablation in patients with osteoid osteoma

OBJECTIVE

To assess the long-term outcome of computed tomography-guided radiofrequency ablation (CT-guided RFA) in patients with suspected osteoid osteoma (OO).

MATERIALS AND METHODS

Single-center retrospective study. Patients with clinical suspicion and imaging diagnosis of osteoid osteoma were treated by CT-guided RFA using the same device with either a 7- or 10-mm active tip electrode. Specific precautions were applied in case of articular or spinal OO. Patients were contacted by phone to evaluate the long-term outcome in terms of pain, ability to perform daily activities (including sports), and long-term complications. Success was defined as the absence of residual pain and ability to perform daily activities normally.

RESULTS

From 2008 to 2015, 126 patients were treated by CT-guided RFA for OO in our institution. Mean patient age was 26.1 years (SD = 11, range 1-53); mean delay to diagnosis was 16.9 months (SD = 15.2, range 1-120). Among patients who answered the follow-up call (n = 88), the overall success rate was 94.3%: 79/88 (89.8%) had primary success of the procedure, and 4/88 (4.5%) had a secondary success (repeat-RFA after pain recurrence). Mean follow-up time was 34.6 months (SD = 24.7, range 3-90). Few complications occurred: two mild reversible peripheral nerve injuries, one brachial plexus neuropathy, one broken electrode tip fragment, and one muscular hematoma.

CONCLUSION

Osteoid osteoma can be effectively and safely treated by CT-guided RFA using the presented ablation protocol. Beneficial effects of the treatment persist at long-term follow-up.

Anterior Impingement Syndrome of the Ankle Caused by Osteoid Osteoma in the Talar Neck Treated with Arthroscopy and 3D C-Arm-Based Imaging

Osteoid osteoma in periarticular lesions tends to have an unusual presentation that likely leads to a delayed or missed diagnosis compared with a typical osteoid osteoma in the metaphysis or diaphysis of the long bone. In cases that are unresponsive to conservative treatment, surgical interventions including en bloc resection, computed tomography-guided percutaneous treatment, and arthroscopic resection have been performed; however, these methods frequently result in inadequate tumor resection and recurrence. Here we present a case of a 16-year-old girl with osteoid osteoma in the talar neck presenting as anterior impingement syndrome due to marked synovitis in the ankle joint which was successfully treated without complications by arthroscopic synovectomy and tumor resection followed by intraoperative 3D C-arm-based imaging confirming complete tumor lesion removal. Her pain was relieved immediately after the surgery, and there was no recurrence at 12 months of follow-up. This is the first case report of the surgical treatment of the osteoid osteoma in the talar neck with the combination methods of arthroscopy and 3D C-arm-based imaging.

Phase I/II Multi-Institutional Study of Percutaneous Radiofrequency Ablation for Painful Osteoid Osteoma (JIVROSG-0704)

PURPOSE

This multicenter prospective study was conducted to evaluate the safety and efficacy of percutaneous radiofrequency ablation (RFA) for painful osteoid osteoma (OO).

MATERIALS AND METHODS

Patients with OO (femur: n = 17, tibia: n = 2, humerus: n = 1, rib: n = 1) were enrolled and treated with RFA. In phase I, nine patients were evaluated for safety. In phase II, 12 patients were accrued, and an intent-to-treat analysis was performed on all patients. The primary endpoint was to evaluate the treatment safety. The secondary endpoint was to evaluate the efficacy for pain relief by the visual analogue scale (VAS) at 4 weeks after RFA. Treatment efficacy was classified as significantly effective (SE) when VAS score decreased by ≥5 or score was <2, moderately effective when VAS score decreased by <5-≥2 and score was ≥2, and not effective (NE) when VAS score decreased by <2 or score was increased. Cases where the need for analgesics increased after treatment were also NE.

RESULTS

RFA procedures were completed in all patients. Minor adverse effects (AEs) were observed as 4.8-14.3 % in 12 patients, and no major AEs were observed. Mean VAS score was 7.1 before treatment, 1.6 at 1 week, 0.3 at 4 weeks, and 0.2 at 3 months. All procedures were classified as SE. Pain recurrence was not noted in any patient during follow-up (mean: 15.1 months).

CONCLUSION

RFA is a safe, highly effective, and fast-acting treatment for painful extraspinal OO. Future studies with a greater number of patients are needed.

Effectiveness of Computed Tomography Guided Percutaneous Radiofrequency Ablation Therapy for Osteoid Osteoma: Initial Results and Review of the Literature

Background

The aim of this retrospective study is to determine our experience of technique success rate, complications and clinical results in long term follow up for computed tomography (CT)-guided radiofrequency ablation [RA] therapy for osteoid osteoma (OO).

Material/Methods

We performed RA therapy to 18 patients with OO referred to interventional radiology from other clinics primarily from orthopedics; between January 2011 to May 2014. Daytime and nighttime pain intensity of 18 patients was noted according to visual analog scale (VAS). After procedure pain intensity was compared with before one. We also discussed other factors can affect it.

Results

All procedures were completed technically successful for all patients [100%]. We did not experience any major complication or mortality. However we had 3 minor complications. Pain came back in 1 patient after 5 months from procedure and it was considered as recurrence. Dramatic pain intensity fall was seen in patients after procedure, both daytime and nighttime. However we did not find and statistically significant change in comparison of pain intensity reduce and time needed to return back to routine life when using patients demographic data and lesion size.

Conclusions

CT guided RA therapy of OO is minimally invasive, effective and secure procedure.

Treatment of focal benign lesions of the bone: MRgFUS and RFA

The objective of this study was to evaluate the role of MR-guided focused ultrasound surgery and radiofrequency ablation in the management of bone and soft-tissue lesions. Musculoskeletal interventional radiology represents an interesting option for the treatment of benign bone and soft-tissue lesions to avoid the invasiveness of surgery and related risks. The imaging techniques now available, besides representing an optimal guide, allow control of the temperature reached in the region of interest, avoiding or minimizing damage to the sensitive structures surrounding the lesion.

Establishing a clinical service for the treatment of osteoid osteoma using magnetic resonance-guided focused ultrasound: overview and guidelines

Recent studies have demonstrated the effectiveness of magnetic resonance-guided focused ultrasound (MRgFUS) in the treatment of osteoid osteoma (OO), a painful, benign bone tumor. As MRgFUS is a noninvasive and radiation-free treatment, it stands to replace the current standard of care, percutaneous radiofrequency, or laser thermal ablation. Within an institution, creation of a clinical OO MRgFUS treatment program would not only provide cutting edge medical treatment at the current time but would also establish the foundation for an MRgFUS clinical service to introduce treatments currently under development into clinical practice in the future. The purpose of this document is to provide information to facilitate creation of a clinical service for MRgFUS treatment of OO by providing (1) recommendations for the multi-disciplinary management of patients and (2) guidelines regarding current best practices for MRgFUS treatment. This paper will discuss establishment of a multi-disciplinary clinic, patient accrual, inclusion/exclusion criteria, diagnosis, preoperative imaging, patient preparation, anesthesia, treatment planning, targeting and treatment execution, complication avoidance, and patient follow-up to assure safety and effectiveness.

Osteoid osteoma of the foot and ankle--A systematic review

BACKGROUND

Osteoid osteomas are responsible for 10% of benign bone tumours. Treatment typically involves surgical excision or radio frequency ablation. The aim of this systematic review is to evaluate reported cases of foot and ankle osteoid osteomas.

METHODS

We conducted a systematic review of the literature using the online databases Medline and EMBASE. We included studies reporting osteoid osteoma diagnosed either radiologically or histologically.

RESULTS

94 studies were included reporting 223 cases; 70.5% were male, mean age was 23 years, 69% reported night pain and 72% responded to NSAIDs. The commonest affected bone was the talus. CT scan was the most useful radiological investigation and MRI missed the diagnosis in 34% of cases. The majority of patients underwent surgical excision but an increasing trend of ablation therapy was demonstrated.

CONCLUSIONS

A high index of suspicion based on salient history and appropriate imaging are essential for timely identification and treatment.

Hip arthroscopy for the management of osteoid osteoma of the acetabulum: a systematic review of the literature and case report

Background

Intra-articular osteoid osteoma (OO) causes irreversible joint damage. Its treatment of choice is radiofrequency ablation (RFA); however, some areas of the acetabulum are hard to access. Therefore, hip arthroscopy was used to treat this tumor. We aim to systematically review the literature with regards to arthroscopic management of acetabular OO, and to report a further case in which hip arthroscopy was used for treatment.

Methods

PubMed and EMBASE were searched for articles relevant to the arthroscopic management of acetabular OO on December 2, 2014. All articles published on and before that date were reviewed, and studies which met our pre-determined inclusion criteria were included. Articles screening and data abstraction were done by two reviewers independently. We also presented a 31-year-old man with acetabular OO who underwent hip arthroscopy for the management of his tumor after failing to respond to medications and computed tomography scan (CT)-guided RFA.

Results

The initial search revealed 14 studies, of which ten met our inclusion criteria. A total of ten patients underwent hip arthroscopy for the management of acetabular OO. Only two patients were females, and the patients' age ranged from 7 to 47 years. Two patients underwent arthroscopic guided-RFA of the lesion, while the rest underwent excision. The follow-up period ranged from 6 months to 2 years. Success rate was 100 %, and no recurrence was reported. Minor complications (transient impotence and perineal numbness) developed in one patient (10 %). Arthroscopic-guided RFA failed to eliminate the tumor in our additional case. A second trial of CT-guided RFA was successful in treating the patient's condition.

Conclusions

Hip arthroscopy is an effective and safe option for the management of acetabular OO, with success rate exceeding 90 %. Studies of higher level of evidence are required.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-015-0779-8) contains supplementary material, which is available to authorized users.