Osteoid osteomas in common and in technically challenging locations treated with computed tomography-guided percutaneous radiofrequency ablation

Intraoperative Identification and Mosaicplasty in a Case of Femur Subchondral Osteoid Osteoma

Osteoid osteomas (OOs) are non-malignant primary bone abnormalities marked by a central nidus surrounded by reactive sclerosis. They typically manifest as aggravated nocturnal pain that responds to non-steroidal anti-inflammatory drugs (NSAIDs). These growths are most frequently found within the intracortical bone and the diaphysis of elongated bones. Within the realm of uncommon conditions, intra-articular OOs (IAOOs) exhibit distinctive presentations, often leading to postponed or inaccurate diagnoses. We present a patient with OO at the distal femur, accessible through the knee joint, which was intraoperatively identified and localized using a needle pricking technique and treated by arthrotomy and mosaicplasty.

CT-guided radiofrequency ablation of painful intra-articular osteoid osteoma in children: Is there a concern for cartilage damage?

OBJECTIVE

To evaluate the safety and efficacy of computed tomography-guided percutaneous radiofrequency ablation (PRFA) in the management of uncommon and technically challenging intra-articular osteoid osteoma in children.

MATERIAL AND METHODS

From December 2018 to September 2022, 16 children with intra-articular osteoid osteoma, including ten boys and six girls, were treated at two tertiary centers with percutaneous CT-guided RF ablation using a straight monopolar electrode. The procedures were carried out under general anesthesia. Post-procedural clinical outcomes and adverse events were assessed through clinical follow-up.

RESULTS

Technical success was achieved in all of the participating patients. Clinical success with relief of symptomatology throughout the period of follow-up was achieved in 100% of the patients. No persistence or recurrence of pain occurred during the follow-up period. No immediate or delayed adverse effects were observed.

CONCLUSION

PRFA is shown to be technically feasible. Clinical improvement can be achieved with a high rate of success in the treatment of children with difficult-to-treat intra-articular osteoid osteomas.

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.

Comparison of arthroscopy versus percutaneous radiofrequency thermal ablation for the management of intra- and juxta-articular elbow osteoid osteoma: case series and a literature review

BACKGROUND

Today, intra-articular and juxta-articular osteoid osteomas are treated with arthroscopy and radiofrequency thermal ablation. However, for the case of an elbow joint, arguments are made for the use of a minimally invasive technique to be the optimal choice. This study aims to analyse our experiences of arthroscopically treated elbow osteoid osteomas and to compare it with the published results of both techniques.

METHODS

The retrospective study analyses the patients who underwent elbow arthroscopy ablation of an elbow osteoid osteoma at a single institution from January 2014 until March 2020. Clinical and diagnostic features, success and treatment failure rates, complications and tumour recurrence rates were all compared to 13 studies of intra-articular elbow osteoid osteoma arthroscopic ablation and 15 studies involving radiofrequency thermal ablation of intra-articular osteoid osteoma within different joints.

RESULTS

Four males and two females, with a mean age of 19.3 years, were encompassed. All the patients had immediate postoperative pain relief and improved range of motion. No tumour recurrences were observed during a median of 21.7 months. The literature review yielded 86.4% success rate, 68.2% successful biopsies, one minor complication and no recurrences following the arthroscopic ablation of an elbow osteoid osteoma; while radiofrequency thermal ablation of an intra-articular elbow osteoid osteoma yielded 96.3% success rate, 33.3% successful biopsies, no complications and 3.7% recurrence rate.

CONCLUSIONS

Our results are consistent with the published literature proving that arthroscopic ablation is an efficient method with low treatment failure rates and no recurrences in treating intra- and juxta-articular elbow osteoid osteomas. Advantages of arthroscopic ablation stem from the ability to visualise and safely deal with the lesion and the joint's reactive changes resulting in high biopsy rates, no recurrences and better postoperative elbow's range of motion. Still, the technique selection should be personalised considering the medical expertise of every institution.

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.

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.

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.

Radiofrequency ablation vs microwave ablation for osteoid osteomas: long-term results

OBJECTIVE

Osteoid osteomas are benign bone tumors commonly treated using thermal ablation. We compare the technical success, complication rates, and long-term efficacy of the two most common ablation types: radiofrequency and microwave.

MATERIALS AND METHODS

A retrospective study was performed of all osteoid osteoma ablation procedures between 2007 and 2017. A ten-point numerical pain scale was used to quantify symptoms before and after the procedures with > 12-month follow-up. Complications were reported using the Society of Interventional Radiology Adverse Events reporting criteria.

RESULTS

Twenty-nine patients successfully underwent 15 radiofrequency ablations and 15 microwave ablations with a technical success rate of 83% for radiofrequency and 100% for microwave (p = 0.23). Long-term recurrence rates (p = 1.0) and complication rates (p = 0.60) were not significantly different for the groups. One patient developed a skin burn following microwave ablation and another developed 12 months of sciatic neuropathy following radiofrequency ablation.

CONCLUSION

Microwave and radiofrequency ablation are safe and effective methods for treating osteoid osteomas with similar long-term efficacies. Although radiofrequency ablation is more commonly reported to result in skin burns, this complication can arise during microwave ablation.

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.

Arthroscopic Management of Osteoid Osteoma of the Ankle Joint: A Systematic Review of the Literature

Osteoid osteomas (OOs) are rare benign bone tumors that may occur in various joints including the ankle. These tumors are generally removed via open surgical excision or radiofrequency ablation. However, when they occur intra-articularly, these treatments are more difficult to perform because of more difficult access and the increased risk of damaging articular cartilage. Therefore, some have advocated for the use of arthroscopy to treat these cases. This systematic review aims to investigate the safety and efficacy of arthroscopic treatment for intra-articular OO of the ankle. Using Medline and Embase, we systematically reviewed the literature as of May 31, 2017. All articles published on and before that date were reviewed by 2 independent reviewers. Seventeen articles containing a total of 27 cases were included in the review. Most reported cases were in the talar neck, followed by the distal tibia. Of all the cases, only 2 recurrences were reported (in the same patient), and no complications were reported. Therefore, these cases demonstrate arthroscopic excision of intra-articular OO of the ankle as a safe and effective alternative to open surgical excision and radiofrequency ablation, with a success rate of 96%. However, all articles found were case studies or small case series owing to the rarity of this disease. In the future, analyses of case series with larger case collections should be performed.

Intra-articular Osteoid Osteoma of the Distal Femur Treated with Osteochondral Grafting: A Report of 2 Cases

CASE

Intra-articular osteoid osteoma (IAOO) is a relatively rare entity and can pose a therapeutic challenge due to proximity to the cartilage surface. We present 2 cases of subchondral osteoid osteomata within the distal femur treated with excision and osteochondral grafting of the resultant defect.

CONCLUSIONS

Subchondral IAOO can pose a therapeutic challenge. Our patients had an effective pain relief and return to activities with this treatment strategy.

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.

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.

Percutaneous radiofrequency ablation in osteoid osteoma: Tips and tricks in special scenarios

OBJECTIVES

To define specific characteristics of osteoid osteomas treated with radiofrequency ablation, that may benefit from special technical recommendations.

METHODS

Retrospective analysis of all radiofrequency ablations performed by our group from January 2001 to March 2015. A descriptive study was conducted. We compared our results with the available literature to determine the most frequent special scenarios.

RESULTS

207 radiofrequency ablations were performed in 200 patients. We defined the following scenarios: osteoid osteomas located in the spine, close to neurovacular structures, osteoid osteomas in small bones (hands and feet), intra-articular, deeply located or superficial and lesions with extensive periosteal reaction.

CONCLUSIONS

The scenarios defined required special considerations and technical variations. Implementing the different tips and tricks shown in the article, the most complex osteoid osteomas could be successfully ablated.

Neurophysiological Monitoring in Radiofrequency Ablation of Spinal Osteoid Osteoma With a Progressive Time and Temperature Protocol in Children

STUDY DESIGN

Retrospective. Level IV Evidence.

OBJECTIVE

To assess the utility of intraoperative neurophysiological monitoring (IONM) to detect and eventually prevent impending neurovascular damage during computed tomography (CT)-guided radiofrequency ablation (RFA) of spinal osteoid osteoma (OO) in children.

SUMMARY AND BACKGROUND DATA

To our knowledge, this is the first case series of spinal OO in pediatric patients treated at a single center employing IONM during RFA.

METHODS

This is a retrospective study of seven consecutive patients (3 girls and 4 boys, mean age: 9 years 4 months) with imaging and clinical signs compatible with spinal OO who underwent CT-guided RFA, under general anesthesia, and IONM in a single center between 2011 and 2015. Before the RFA procedure, a CT-guided percutaneous biopsy of the nidus was performed in the same setting. RFA was divided into four cycles of increasing time and temperature and performed under IONM in every patient.

RESULTS

Two patients had lesions located in the thoracic spine and five patients had lumbar involvement. The RFA technical and clinical success was 85.7%. Six patients presented with reversible neurophysiological changes either during biopsy needle positioning or RFA cycles. In the remaining case, as IONM changes did not improve after several minutes of neuroprotective hypertension, the procedure was interrupted. Neither neurologic nor vascular complications were observed after RFA treatment. In only one biopsy sample, OO was confirmed by histopathologic studies.

CONCLUSION

CT-guided RFA is an accepted minimally invasive technique for the treatment of spinal OO in children. IONM may be a helpful tool that requires minimal additional time and provides feedback on the state of the spinal cord and nerves at risk during the procedure. We promote the use of IONM during these procedures to detect and possibly prevent impending neurologic damage.

LEVEL OF EVIDENCE

Level IV.

Osteoid osteoma of the acetabulum successfully treated with computed tomography-guided resection and ablation using a standard electrosurgical generator: a case report

Background

Osteoid osteoma accounts for approximately 10% of all benign bone tumors. The most common sites of osteoid osteoma are the subcortical shaft and metaphyses of long bones, but any other skeletal bone site can be involved. The acetabulum is a rare site according to past reports. This site presents challenges to optimal management because it is anatomically difficult to approach, and because its rarity leads to limited experience with therapeutic procedures. Here, we report for the first time a rare case of osteoid osteoma in the acetabulum that was successfully treated via resection of the nidus and ablation using a standard electrosurgical generator under computed tomographic guidance.

Case presentation

A 9-year-old Japanese girl presented at a clinic with left hip pain without apparent cause for 1 month. She was diagnosed as having coxitis simplex. However, her pain did not change for 1 year and she was admitted to another hospital where osteoid osteoma in her left acetabulum was suspected. She was then referred to our hospital approximately 1 year after first symptom presentation, where she presented with severe left hip pain and was completely unable to walk. Computed tomography examinations revealed a well-demarcated 5 mm mass with bone sclerosis in her left acetabulum. The mass was characterized by low intensity on T1 and high intensity on T2 magnetic resonance images. These findings were consistent with osteoid osteoma of left acetabulum. She underwent computed tomography-guided resection of nidus and ablation using a standard electrosurgical generator. A histological examination confirmed acetabular osteoid osteoma. Complete pain relief was achieved after the procedure and she experienced no complications. She could walk without any pain at the final follow-up 1 year post-treatment and no local recurrence was observed.

Conclusions

We successfully treated acetabulum osteoid osteoma without any symptom recurrence by computed tomography-guided resection and ablation using a standard electrosurgical generator. In addition, we preserved our patient’s sciatic nerve and triradiate cartilage. Our report provides evidence that a computed tomography-guided procedure should be considered the treatment of choice for osteoid osteoma of the acetabulum because it is a less invasive alternative to en bloc resection.

Percutaneous Biopsy and Radiofrequency Ablation of Osteoid Osteoma with Excess Reactive New Bone Formation and Cortical Thickening Using a Battery-Powered Drill for Access: A Technical Note

PURPOSE

To report our experience with the use of a battery-powered drill in biopsy and radiofrequency ablation of osteoid osteoma with excess reactive new bone formation. The battery-powered drill enables obtaining the sample while drilling.

MATERIALS AND METHODS

During the last 18 months, 14 patients suffering from painful osteoid osteoma with excess reactive new bone formation underwent CT-guided biopsy and radiofrequency ablation. In order to assess and sample the nidus of the osteoid osteoma, a battery-powered drill was used. Biopsy was performed in all cases. Then, coaxially, a radiofrequency electrode was inserted and ablation was performed with osteoid osteoma protocol. Procedure time (i.e., drilling including local anesthesia), amount of scans, technical and clinical success, and the results of biopsy are reported.

RESULTS

Access to the nidus through the excess reactive new bone formation was feasible in all cases. Median procedure time was 50.5 min. Histologic verification of osteoid osteoma was performed in all cases. Radiofrequency electrode was coaxially inserted within the nidus and ablation was successfully performed in all lesions. Median amount CT scans, performed to control correct positioning of the drill and precise electrode placement within the nidus was 11. There were no complications or material failure reported in our study.

CONCLUSIONS

The use of battery-powered drill facilitates access to the osteoid osteoma nidus in cases where excess reactive new bone formation is present. Biopsy needle can be used for channel creation during the access offering at the same time the possibility to extract bone samples.

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.

Percutaneous bone lesion ablation

Benign tumors and metastatic bone lesions can be treated by ablation techniques performed either alone or in combination with other percutaneous techniques. Ablation techniques include ethanol or acetic acid injection and thermal ablation by means of energy deposition [including laser, radiofrequency, microwave, cryoablation, radiofrequency ionization and magnetic resonance (MR)-guided high-intensity focused ultrasound (HIFU)]. Goal definition of the therapy is crucial: ablation techniques can be proposed as curative treatments in benign bone tumors or oligometastatic disease (<3 lesions). Alternatively, these techniques can be proposed as palliative treatments aiming at reduction of pain, local control of the disease and tumor decompression. Depending on the lesion's location ablation can be combined with cementation with or without further metallic augmentation; local tumor control can be enhanced by combining ablation with transarterial bland embolization or chemoembolization. Thermal ablation of bone and soft tissues is characterized by high success and relatively low rates of potential complications, mainly iatrogenic thermal damage of surrounding sensitive structures. Successful thermal ablation requires a sufficient ablation volume and thermal protection of the surrounding vulnerable structures. This article will describe the general principles governing ablation and the mechanism of action for each technique and in addition will review the literature about safety and effectiveness of percutaneous imaging-guided ablation for benign and malignant (primary and metastatic) lesions.

Percutaneous image-guided ablation of bone and soft tissue tumours: a review of available techniques and protective measures

Background

Primary or metastatic osseous and soft tissue lesions can be treated by ablation techniques.

Methods

These techniques are classified into chemical ablation (including ethanol or acetic acid injection) and thermal ablation (including laser, radiofrequency, microwave, cryoablation, radiofrequency ionisation and MR-guided HIFU). Ablation can be performed either alone or in combination with surgical or other percutaneous techniques.

Results

In most cases, ablation provides curative treatment for benign lesions and malignant lesions up to 3 cm. Furthermore, it can be a palliative treatment providing pain reduction and local control of the disease, diminishing the tumour burden and mass effect on organs. Ablation may result in bone weakening; therefore, whenever stabilisation is undermined, bone augmentation should follow ablation depending on the lesion size and location.

Conclusion

Thermal ablation of bone and soft tissues demonstrates high success and relatively low complication rates. However, the most common complication is the iatrogenic thermal damage of surrounding sensitive structures. Nervous structures are very sensitive to extremely high and low temperatures with resultant transient or permanent neurological damage. Thermal damage can cause normal bone osteonecrosis in the lesion’s periphery, surrounding muscular atrophy and scarring, and skin burns. Successful thermal ablation requires a sufficient ablation volume and thermal protection of the surrounding vulnerable structures.

Teaching points

• Percutaneous ablations constitute a safe and efficacious therapy for treatment of osteoid osteoma.

• Ablation techniques can treat painful malignant MSK lesions and provide local tumour control.

• Thermal ablation of bone and soft tissues demonstrates high success and low complication rates.

• Nerves, cartilage and skin are sensitive to extremely high and low temperatures.

• Successful thermal ablation occasionally requires thermal protection of the surrounding structures.

Osteoid osteoma

Osteoid osteomas consist of a nidus with surrounding sclerotic bone. The differential diagnosis covers a wide range of conditions due to the variable presentation of osteoid osteoma. The natural history is for regression to occur within 6 to 15 years with no treatment; however, this can be reduced to 2 to 3 years with the use of aspirin and non-steroidal anti-inflammatory drugs. Computed tomography-guided percutaneous techniques, including trephine excision, cryoablation, radiofrequency ablation, and laser thermocoagulation, are described.

Percutaneous navigation surgery of osteoid osteoma of the femur neck

Surgery on benign bone tumors such as osteoid osteoma does not necessarily require bone exposure through a surgical incision. In most reported cases of the osteoid osteoma resection through computer-assisted surgery, registration and surgery were performed by exposing the bone. We have succeeded in performing percutaneous registration and navigated burr excision of the osteoid osteoma using computer-assisted navigation.

Case report: Osteoid osteoma of the acetabulum treated with arthroscopy-assisted radiofrequency ablation

BACKGROUND

Osteoid osteomas consist of a nidus surrounded by reactive sclerotic bone. The diagnosis typically is based on imaging and clinical presentation involving nocturnal pain. Removal of the lesion is essential and currently is performed mainly with image-guided, minimally invasive techniques. We describe a case involving an osteoid osteoma of the acetabular fossa, treated with arthroscopy-assisted radiofrequency ablation.

CASE DESCRIPTION

A 47-year-old woman presented with a 9-month history of right groin pain and limited motion. The CT and MR images showed synovitis around the ligamentum teres and a nidus of the acetabular fossa, surrounded by sclerotic bone and protruding from the inner part of the lamina quadrilateral. Synovectomy and debridement of the ligamentum teres were performed, followed by radiofrequency ablation of the osteoid osteoma under direct arthroscopic observation of the hip, avoiding resection of the normal bone around the nidus and preserving the integrity of the quadrilateral lamina and cartilage. The patient had complete pain relief the next day with minimal morbidity and rapid functional restoration. At the 22-month clinical followup, the patient was asymptomatic, and the CT and MR images obtained 1 year after surgery showed no pathologic signs or synovitis.

LITERATURE REVIEW

Our case was the fifth such case to be treated with hip arthroscopy and the first of these to our knowledge to be treated with the arthroscopy-assisted radiofrequency ablation technique.

PURPOSES AND CLINICAL RELEVANCE

Arthroscopy-assisted radiofrequency ablation is a combined treatment technique that may be used for intraarticular lesions of the hip that otherwise would require a difficult approach and jeopardize damage to cartilage and bone and also treat concomitant synovitis.

CT-guided percutaneous drilling is a safe and reliable method of treating osteoid osteomas

Computed tomography (CT)-guided percutaneous drilling is an alternative for osteoid osteoma treatment. This study aims to evaluate the remodeling of the drill orifice. The success rate and complications were also recorded and compared with other treatment methods. Fifteen patients with an average age of fourteen years (ranging from 4 to 25) submitted to CT-guided percutaneous drilling between 2003 and 2009 were retrospectively analyzed according to clinical and radiological criteria. Fourteen cases showed complete alleviation of pain one week after surgery. No relapse was detected even in the subject who continued complaining of pain. All patients were treated with a day-hospital regimen and were discharged with partial weight bearing. Total weight bearing was allowed after one month, and sports were allowed after consolidation, which occurred in all but one case after the third month. One patient, who did not follow our medical advice, returned to sports activities after two weeks and experienced a fracture as a result. Atrophy of the vastus lateralis muscle developed after the procedure in another patient. Our case series suggests that this method is reliable and safe. The level of complexity is comparable with other minimally invasive percutaneous procedures. The cost is low because there is no need to buy probes or other equipment. The negative points include weakening of the bone and the logistical problem of assembling the orthopedic surgeon, radiologist, and anesthesiologist in the tomography room.

CT-guided radiofrequency ablation of osteoid osteoma in the long bones of the lower extremity

AIM: To present our initial experience with computed tomography guided radiofrequency ablation (RFA) of osteoid osteoma (OO) in our institution.

METHODS: RFA was performed on eight patients (5 males and 3 females) with clinically and radiologically diagnosed OO (femoral neck, n = 4; femoral diaphysis, n = 2; tibial diaphysis, n = 1; fibular diaphysis, n = 1). Ablation was performed using an electrode with a 10-mm exposed tip for a total of 4-6 min at a targeted temperature of 90 degrees Celsius. No cooling system was used. The intervention was accepted as technically successful if the tip of the electrode could be placed within the center of the nidus. We defined clinical success as a disappearance within 2 wk after treatment of symptoms that had manifested at presentation.

RESULTS: All procedures were technically successful. No major or immediate complications were observed. Clinical success was achieved in six of eight patients in the first procedure. A second procedure was performed for two patients who had recurrent or continued pain, and one of these cases was successfully treated. The overall rate of success was 87.5% (7/8). No complication was observed.

CONCLUSION: Our preliminary results indicate a favorable success rate and no complications and are compatible with the previous reports of RFA of OO.

Arthroscopic removal of an intra-articular osteoid osteoma of the radial styloid

We describe a case of intra-articular osteoid osteoma arising in the radial styloid of a 21-year-old man. Plain radiographs were not diagnostic, but computed tomography, gadolinium-enhanced magnetic resonance imaging, and bone scintigraphy suggested the possibility of an osteoid osteoma. We arthroscopically removed the lesion; histological examination confirmed the diagnosis. The patient's symptoms disappeared immediately after surgery.

Osteoid osteoma and osteoblastoma

Osteoid osteoma and osteoblastoma are commonly seen benign osteogenic bone neoplasms. Both tumors are typically seen in the second decade of life, with a notable predilection in males. Histologically, these tumors resemble each other, with characteristically increased osteoid tissue formation surrounded by vascular fibrous stroma and perilesional sclerosis. However, osteoblastomas are larger than osteoid osteomas, and they exhibit greater osteoid production and vascularity. Clinically, osteoid osteoma most commonly occurs in the long bones (eg, femur, tibia). The lesions cause night pain that is relieved with nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoblastoma is most frequently located in the axial skeleton, and the pain is usually not worse at night and is less likely to be relieved with NSAIDs. Osteoblastoma can be locally aggressive; osteoid osteoma lacks growth potential. Osteoid osteoma may be managed nonsurgically with NSAIDs. When surgery is required, minimally invasive methods (eg, CT-guided excision, radiofrequency ablation) are preferred. Osteoblastoma has a higher rate of recurrence than does osteoid osteoma, and patients must be treated surgically with intralesional curettage or en bloc resection.

Recurrent osteoid osteoma: interstitial laser ablation under magnetic resonance imaging guidance

Thermal ablation has become a therapy of choice in the treatment of osteoid osteomas. To date, computed tomography has been the standard imaging modality for minimally invasive treatment regimes. We report a case of a 46-year-old man with a recurrent osteoid osteoma in the right tibial head after CT-guided drill excision and repeat treatment with laser ablation under open high-field MRI guidance. We describe the steps of the interventional MRI procedure and discuss related innovative guidance and monitoring features, and potential benefits of MRI compared with CT-guided techniques. In conclusion, MR-guided laser ablation was proved to be safe and effective.