CT-guided radiofrequency ablation of osteoid osteoma: long-term results

Remodeling of Lumbar Spinal Osteoid Osteoma Resected With Microscopic Surgery in a 15-Year-Old Basketball Player: A Case Report

This case report focuses on a 15-year-old competitive-level high school basketball player who experienced chronic low back pain. Diagnostic imaging revealed osteoid osteoma in the L5 posterior element, causing osteosclerotic deformity of the left lamina and more inferior facet. To return him to the condition of sports activity, less invasive surgery of microscopic tumor resection with autologous bone grafting was planned instead of CT-guided ablation, which can cause thermal injury to nearby tissues. This procedure could preserve spinal structures, including the facet, pedicle, and paravertebral muscles. The day after surgery, the patient experienced a complete resolution of lower back pain. He gradually resumed light exercise two months postoperatively. Three-month follow-up CT imaging revealed bone remodeling at the resection site, to return to complete basketball activities. Over five years, no tumor recurrence or symptoms were observed, and he maintained his competitive activity level.

Osteoid Osteoma of the Proximal Femur: Pitfalls in Diagnosis and Performance of Open Surgical Resection

Aims

Proximal femoral osteoid osteoma (OO) is extremely easy to be misdiagnosed or missed. The purpose of this study was to retrospectively analyze the clinical data of patients with proximal femoral OO in order to determine the clinical manifestation and imaging characteristics of the disease, so as to provide help for the preoperative diagnosis and clinical treatment of proximal femoral OO.

Methods

This was a retrospective study involving 35 patients with proximal femoral OO admitted into our hospital from January 2015 to January 2021. The baseline characteristics of the participants included; 24 males and 11 females, aged between 13 and 25 (mean 16.2) years old, and the course of the disease was 1 to 14 (mean 6.3) months. We used previous medical experience records of the patients to analyze for the causes of misdiagnosis. Moreover, we compared the difference between preoperative and postoperative treatment practices in alleviating pain in OO patients and restoring hip function. Follow-ups were carried out regularly, and patients advised to avoid strenuous exercises for 3 months.

Results

We followed up 35 patients (25 intercortical, 4 sub-periosteal, and 6 medullary) for an average of 41.4 months. We found that 15 patients (42.9%) had been misdiagnosed of synovitis, perthes disease, osteomyelitis, intra-articular infection, joint tuberculosis and hip impingement syndrome, whose average time from symptoms to diagnosis were 6.3 months. Postoperative pain score and joint function score improved significantly compared with preoperative, and complications were rare.

Conclusion

Open surgical resection constitutes an effective treatment for proximal femoral OO by accurately and completely removing the nidus. Wrong choice of examination, and the complexity and diversity of clinical manifestations constitutes the main reasons for the misdiagnosis of proximal femoral OO.

Computed tomography guided radiofrequency ablation of osteoid osteoma in children: a single center's experience

OBJECTIVE

To report a single center's experience evaluating the efficacy and safety of computed tomography-guided radiofrequency ablation for the treatment of osteoid osteoma in children.

MATERIALS AND METHODS

Institutional database research identified 33 symptomatic patients (≤ 18 years of age; male/female ratio: 21/12, mean age 13.09 ± 3.66) with osteoid osteoma who were treated by CT-guided RFA. Technical and clinical success as well as complication rates were recorded. The duration of the procedure, the number of computed tomography scans and the results of the biopsy were assessed. Pain, prior, the following morning and 1 week, 1/6/12 months after the procedure were compared by means of a numeric visual scale (NVS) questionnaire.

RESULTS

Mean lesion size was 8.28 ± 4.24 mm. Mean follow-up was 23.33 ± 17.61 months (range 12-62). Mean pain score prior to radiofrequency ablation was 9.06 ± 0.80 NVS units. On week 1 and 1/6/12 months, all patients were pain-free reporting 0 NVS units (p < 0.05). The mean procedure time was 54 min (range 51-59) and a mean of 7 CT scans were performed during the ablation session. RF electrode was successfully placed in the center of the nidus in all cases. In our study, none of our patient experienced recurrence of the pain, nor complications.

CONCLUSION

The present study demonstrates that percutaneous CT-guided radiofrequency ablation constitutes a safe and effective technique for osteoid osteoma treatment in children.

A Missed Case of Osteoid Osteoma of the Acetabulum Treated with a Novel Computed Tomography-Guided Technique - A Case Report

Introduction:

Osteoid osteoma is a benign osteoblastic bone tumor that mostly arises from the long bones. The acetabulum is a rare site for osteoid osteoma. Moreover, juxta-articular location of the lesion can be associated with delayed diagnosis. We present a case of a juxta-articular osteoid osteoma of the acetabulum that was missed earlier. We also present a novel, easy, and cost-effective way to accurately localize and excise such a lesion, thereby avoiding failure and recurrence.

Case Report:

A 15-year-old female presented with a history of insidious onset pain in the right hip for 18 months. Pain was diffuse over the hip. She had undergone a failed biopsy in another hospital. She visited us 1 month later with persistent pain. Examination revealed tenderness over the right anterior hip joint line with painful terminal hip flexion. Computed tomography (CT) suggested an osteoid osteoma of the superolateral acetabular rim. The patient was planned for CT-guided mini-open excision biopsy of the lesion. CT-guided localization of the lesion was performed under local anesthesia in the CT room, followed by open excision of the nidus in the operating room. Histopathology confirmed the diagnosis and a complete excision. At last follow-up at 1 year, the patient was asymptomatic and returned to normal function.

Conclusion:

Osteoid osteoma of the acetabulum is uncommon and the diagnosis is usually delayed. A high index of suspicion is needed to avoid a missed diagnosis and CT-guided approach can help in accurate excision. Our technique to localize and completely excise the lesion is novel, simple, and cost effective and can be easily replicated.

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.

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.

The safety and the efficacy of computed tomography guided percutaneous radiofrequency ablation of osteoid osteoma

Objective

The aim of this study was to investigate the efficacy and safety of Computed Tomography (CT) guided percutaneous Radiofrequency Ablation (RFA) in the treatment of osteoid osteoma (OO).

Methods

A total of 116 patients (82 male and 34 female patients; mean age of 17.7 years; age range 13-months-42 years) who had 118 CT guided RFA treatment between June 2015 and November 2018 (42 moths) with the diagnosis of OO were included in this study. All the patients had pre-procedural CT examinations. The clinical and technical success and the safety of the treatment were evaluated by assessing the clinical pain symptoms, complication rates and recovery of posture and gait.

Results

All the patients had a favorable immediate relief of the known pain caused by osteoid osteoma in 24 h after the procedure. Only in two patients (15-years-old boy with OO in right femoral neck and a 12 years old boy with OO in femur diaphysis) pain relapse was occurred in 3 months and 12 months after RFA and a second RFA was performed. During follow-up they had no pain. The technical success and efficacy-rates of the procedure were recorded as 100% and 98% respectively in this study. No significant complication was observed during treatment or recovery period. Seven minor complications were noted which were successfully treated.

Conclusion

The rapid relief of pain symptoms, low relapse rate and low complication rates demonstrate the efficacy and safety of RFA therapy. RFA is an out-patient procedure that patients can be mobilized immediately after the procedure. RFA can be safely used as a first choice of treatment method in OO therapy.

Level of evidence

Level IV, therapeutic study.

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.

C-arm cone-beam computed tomography-guided minimally invasive open excision of an osteoid osteoma undetectable on fluoroscopy: A case report

•

A robotic C-arm cone-beam computed tomography (CBCT) system provides a clear intraoperative visualization of the osteoid osteoma.

•

C-arm CBCT allowed precise access to the tumor, accurate tumor resection, and minimal sacrifice of the normal bone in osteoid osteoma surgery.

•

Repurpose use of the dilator, retractor, and wider trephine tips achieved more conservative results with a smaller skin incision.

Introduction

The small size of a nidus and the extensive sclerosis around it often make it difficult to identify tumors from the surrounding normal bone by fluoroscopy, and a large amount of bone resection might be required to secure complete removal during osteoid osteoma surgery. In this report, we present the first case of radiographically invisible osteoid osteoma that was successfully resected under a robotic C-arm cone-beam computed tomography (CBCT) imaging system.

Presentation of case

A 14-year-old boy presented with persistent pain around the left knee joint was diagnosed with osteoid osteoma of the left distal femur. Since the tumor was not detectable by intraoperative fluoroscopy, a CBCT system was used for guidance during an open tumor resection. For a less invasive surgery, we repurposed the dilator and retractor of the microendoscopic discectomy (MED) system and resected the tumor using the wider trephine tips for bone biopsy. At the final follow-up one year later, the function of the afflicted limb was normal with no complaint of any symptoms. Plain radiograph at the final follow-up showed new bone formation completely filling the bone defect, without local recurrence.

Discussion

CBCT allowed for clear intraoperative visualization of the osteoid osteoma, thereby promising a secure resection and less invasive osteoid osteoma treatment. Furthermore, the repurposed use of the dilator and retractor of the MED system as well as the wider trephine tips for bone biopsy made the procedure less invasive.

Conclusion

CBCT-guided minimally invasive open excision surgery could be a useful option for the management of radiographically invisible osteoid osteoma.

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.

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.

Radiofrequency ablation for osteoid osteoma - Recurrence rates and predictive factors

BACKGROUND AND PURPOSE

Osteoid osteoma is an infrequent but debilitating benign bone lesion which can be successfully managed by percutaneous radiofrequency ablation (RFA). There are few studies investigating the efficacy and follow-up of this treatment. An arbitrary upper limit of 15 mm has been used to differentiate between osteoid osteoma and osteoblastoma with surgery used for lesions above this limit. We aimed to analyse the cases identified from our prospectively maintained database over a ten year period since adoption of this technique in our unit. The primary objectives were to investigate factors which influenced recurrence and the time period at which patients are at risk of this.

BASIC PROCEDURES

Consecutive patients with confirmed osteoid osteoma were included. Patient demographics, complications, and recurrence were recorded and multiple regression analysis was performed to investigate causation.

MAIN FINDINGS

Within a minimum follow up of 21 months (mean 72), a recurrence rate of 16.3% was noted, higher than the published literature. Cox regression analysis to predict chance of recurrence revealed a relationship between larger lucent diameter and recurrence (p = 0.049, CI 95%, hazard ratio 1.33).

CONCLUSIONS

The traditional cut off between osteoid osteoma and osteoblastoma appears less rigidly defined than previously thought and probably represents a progressive scale with larger lesions responding less well to RFA. This study indicates that each millimetre increase represents a ×1.33 chance of recurrence. Clinicians should counsel patients accordingly with lesions approaching the larger limits of this diagnosis.

Laser Guidance in C-Arm Cone-Beam CT-Guided Radiofrequency Ablation of Osteoid Osteoma Reduces Fluoroscopy Time

Purpose

To assess whether laser guidance can reduce fluoroscopy and procedure time of cone-beam computed tomography (CBCT)-guided radiofrequency (RF) ablations of osteoid osteoma compared to freehand CBCT guidance.

Materials and Methods

32 RF ablations were retrospectively analyzed, 17 laser-guided and 15 procedures using the freehand technique. Subgroup selection of 18 ablations in the hip–pelvic region with a similar degree of difficulty was used for a direct comparison. Data are presented as median (ranges).

Results

Comparison of all 32 ablations resulted in fluoroscopy times of 365 s (193–878 s) for freehand and 186 s (75–587 s) for laser-guided procedures (p = 0.004). Corresponding procedure times were 56 min (35–97 min) and 52 min (30–85 min) (p = 0.355). The subgroup showed comparable target sizes, needle path lengths, and number of scans between groups. Fluoroscopy times were lower for laser-guided procedures, 215 s (75–413 s), compared to 384 s (193–878 s) for freehand (p = 0.012). Procedure times were comparable between groups, 51 min (30–72 min) for laser guidance and 58 min (35–79 min) for freehand (p = 0.172).

Conclusion

Adding laser guidance to CBCT-guided osteoid osteoma RF ablations significantly reduced fluoroscopy time without increasing procedure time.

Level of Evidence

Level 4, case series.

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.

Osteoid osteoma mimicking monoarticular juvenile idiopathic arthritis in a girl

Osteoid osteoma (OO) is a benign osteogenic neoplasm, usually affecting children and young adults, that is typically characterized by nocturnal pain and response to non-steroidal anti-inflammatory drugs. OO is frequently misdiagnosed because it mimics juvenile idiopathic arthritis (JIA), bone infection or malignancy. Herein we report the case of a girl who presented with chronic monoarthritis of the knee mimicking JIA. After 1 year, OO of the femoral distal metaphysis was diagnosed. OO was treated with computed tomography-guided radiofrequency ablation with disappearance of the symptoms and resolution of the neoplasm. No recurrences have been observed 3 years after the treatment. This case highlights that intra-articular or juxta-articular OO should be suspected in the case of misleading symptoms and signs, such as swelling, lack of typical pain and synovial thickening on ultrasound; needle biopsy of the lesion is necessary in the case of confusing imaging.

Microendoscopic Excision of Osteoid Osteoma in the Pedicle of the Third Lumbar Vertebra

We present a rare case of a patient who underwent complete microendoscopic excision of an osteoid osteoma, which induced radiculopathy without nerve root compression. A 20-year-old man presented severe right groin pain that was temporarily relieved by nonsteroidal anti-inflammatory drugs. A computed tomography (CT) scan showed typical features of a nidus located in the inferior cortex of the right L3 pedicle. We performed surgery using a posterior microendoscopic approach. We drilled vertically along the line of the cortex of the caudal pedicle using a high-speed drill. After identifying the tumor, en bloc resection of the nidus was achieved. Immediately after surgery, pain in the right groin disappeared. A CT scan showed that most of the right L3 pedicle remained. This minimally invasive technique preserves spinal structures, including the facet and pedicle, and is a viable option for the treatment of spinal osteoid osteomas located close to vital structures.

Radiofrequency ablation under 3D intraoperative Iso-C C-arm navigation for the treatment of osteoid osteomas

OBJECTIVE

To evaluate the efficacy of intraoperative three-dimensional (3D) Iso-C C-arm-navigated percutaneous radiofrequency ablation (RFA) of osteoid osteomas.

METHODS

35 patients (20 males and 15 females) with osteoid osteomas underwent treatment with intraoperative 3D Iso-C C-arm navigation-guided RFA. The tumour was first biopsied for pathological examination, the core needle was removed and the RFA needle was inserted into the nidus. Post-operative X-rays and CT scans were performed to evaluate the degree of ablation and to assess for recurrence at 3-month follow-up. Patients also completed a visual analogue scale (VAS) both pre-operatively and 3 days post-operatively to subjectively assess pain.

RESULTS

Pathological diagnosis confirmed osteoid osteoma in 19 cases. The other 16 cases were not pathologically diagnosed owing to inadequate biopsy specimens. In all cases, localized pain was immediately relieved following RFA. Patients reported significantly decreased pain, with mean pre-operative VAS scores of 3.4 reducing to 0.80 at 3 days post-operatively and further to 0.06 at 3-month follow-up (p < 0.05). The mean follow-up time was 15.5 months (range: 3-38 months).

CONCLUSION

3D Iso-C C-arm navigation-guided RFA is a safe and effective option for the treatment of osteoid osteomas and may be considered in place of intraoperative CT-guided and open resection.

ADVANCES IN KNOWLEDGE

C-arm image-guided percutaneous RFA mitigates the need for pre-operative CT as well as intraoperative scintigraphy, provides real-time imaging of the anatomy, facilitates accurate resection of the tumour and enables immediate confirmation of excision.

Interventional MSK procedures: the hip

Percutaneous musculoskeletal procedures are widely accepted as low invasive, highly effective, efficient and safe methods in a vast amount of hip pathologies either in diagnostic or in therapeutic management. Hip intra-articular injections are used for the symptomatic treatment of osteoarthritis. Peritendinous or intrabursal corticosteroid injections can be used for the symptomatic treatment of greater trochanteric pain syndrome and anterior iliopsoas impingement. In past decades, the role of interventional radiology has rapidly increased in metastatic disease, thanks to the development of many ablative techniques. Image-guided percutaneous ablation of skeletal metastases provides a minimally invasive treatment option that appears to be a safe and effective palliative treatment for localized painful lytic lesion. Methods of tumour destruction based on temperature, such as radiofrequency ablation (RFA) and cryotherapy, are performed for the management of musculoskeletal metastases. MR-guided focused ultrasound surgery provides a non-invasive alternative to these ablative methods. Cementoplasty is now widely used for pain management and consolidation of acetabular metastases and can be combined with RFA. RFA is also used to treat benign tumours, namely osteoid osteomas. New interventional procedures such as percutaneous screw fixation are also proposed to treat non-displaced or minimally displaced acetabular roof fractures.

Osteoid osteoma as an unusual cause of wrist pain - A case report and review of literature

INTRODUCTION

Wrist pain is very common and there are several causes for this condition. It is extremely important to establish an accurate diagnosis so that appropriate treatment can be directed at the cause.

PRESENTATION OF CASE

We describe a case of a young man who presented to us with wrist pain of insidious onset. He had previous (ganglion) excision from the same wrist. Clinically there was tenderness in the base of second metacarpal with no swelling. The radiograph and MRI scan were suggestive of Brodie's abscess. But surgical exploration and subsequent histopathology showed evidence of osteoid osteoma. The patient had full resolution of symptoms after 3 months of surgery.

DISCUSSION

Osteoid osteoma of the wrist bones is rare. They usually present with atypical pain. The diagnosis of osteoid osteoma is challenging and often missed. A high index of suspicion and appropriate investigations are essential in the diagnosis.

CONCLUSION

We conclude that the diagnosis of osteoid osteoma should be considered in case of wrist pain of unknown aetiology with cystic lesions in the carpal or metacarpal bones.

Osteoid osteoma of distal phalanx of toe: a rare cause of foot pain

Osteoid osteoma is an uncommon benign tumor and causes severe pain, being worse at night, that responds dramatically to nonsteroidal anti-inflammatory medications. An osteoid osteoma of the toe is very rare and arising in a pedal phalanx may be difficult to diagnose. A 34-year-old male has local swelling and tenderness but there were no hyperemia, temperature increase, or clubbing. There was a 2-month history of antibiotic treatment with suspicion of soft tissue infection in another clinic. The osteoid osteoma was completely excised by curettage and nidus removal with open surgical technique. The patient was followed up for 63 months with annual clinical and radiographic evaluations. There was no relapse of the pain and no residual recurrent tumour. Osteoid osteoma may be difficult to distinguish from chronic infection or myxedema. The patients may be taken for unnecessary treatment. The aim of the treatment for osteoid osteoma is to remove entire nidus by open surgical excision or by percutaneous procedures such as percutaneous radiofrequency and laser ablation. Osteoid osteomas having radiologic and clinical features other than classical presentation of osteoid osteoma are called atypical osteoid osteomas. Atypical localized osteoid osteomas can be easily misdiagnosed and treatment is often complicated.

Thermal epiphysiodesis performed with radio frequency in a porcine model

BACKGROUND AND PURPOSE

Current techniques for epiphysiodesis involve opening of cortical windows; use of staples, screws, and tension devices; and fusion with curettes or drills. Complications may have serious consequences. There is a need for a more reliable, precise, and less traumatic procedure that overcomes the known complications from existing techniques. We analyzed a new epiphysiodesis technique using radio-frequency ablation (RFA) in a porcine model.

METHODS

Six 35-kg and two 25-kg immature pigs were used. 1 hind leg of each animal was randomly selected and the proximal tibia growth plate was ablated laterally and medially. The contralateral leg was used as a control. MR images were obtained immediately after the ablation and 12 weeks later for 6 animals, and 24 weeks later for the other 2 animals. CT was done for the 2 animals that were followed for 24 weeks for proof of bone bridges.

RESULTS

Both tibias were equal in length initially. At the 12-week follow-up, there was an average leg length discrepancy of 3.9 mm (95% CI: 3.0-4.8), and at 24 weeks the difference was 8.4 mm and 7.5 mm. No damage to the adjacent tissue was found. Bone bridges and physeal closure were found after 24 weeks. The pigs showed no discomfort after the intervention.

INTERPRETATION

We found RFA to be feasible for epiphysiodesis in a pig model. The method is minimally invasive and recovery may be quick compared to conventional methods. We recommend that the method should be tested in larger-scale safety studies before clinical application.

CT-guided percutaneous cryoablation for osteoid osteoma: initial experience in adults

OBJECTIVE

The purpose of this study was to investigate the safety and efficacy of CT-guided percutaneous cryoablation for the treatment of osteoid osteoma in adults.

MATERIALS AND METHODS

A retrospective case series over a 30-month period involved 10 consecutive adult patients (nine male and one female patients; mean age, 27.9 years; age range, 16-49 years) who underwent CT-guided percutaneous cryoablation for management of osteoid osteoma. Clinical and technical success was evaluated with postprocedure MRI at 4-5 weeks and with digital numeric pain scores taken before and immediately after the procedure, as well as at primary follow-up (4-10 weeks; average, 5 weeks) and secondary follow-up (23-29 weeks; average, 24 weeks).

RESULTS

Clinical and technical success rates were 100%. Average digital numeric pain scores were 7.4 before the procedure, 1.5 after procedure, 0.5 at the primary follow-up, and 0.3 at secondary follow-up. No minor or major complications were noted during the procedure, recovery period, primary follow-up, or secondary follow-up.

CONCLUSION

CT-guided percutaneous cryoablation is safe and effective in the treatment of osteoid osteoma in adults.

Osteoid osteoma treated by percutaneous thermal ablation: when do we fail? A systematic review and guidelines for future reporting

PURPOSE

Osteoid osteoma (OO) is a painful benign bone tumor of the young that is widely treated by percutaneous thermal ablation (PTA) with success rates close to 100%. Nevertheless, some patients have recurrences. We reviewed the literature to understand whether these are true recurrences or incomplete treatments; to analyze safety and efficacy during long-term follow-up in a extremely large cohort of patients; to detail best-practice suggestions from the largest clinical trials as well as report their complications; and to recommend standards for future reporting.

MATERIALS AND METHODS

This study followed the Cochrane's guidelines for Systematic Reviews of Interventions. Inclusion criteria were as follows: (1) prospective or retrospective cohort study for PTA of OO under computed tomography (CT) guidance; (2) CT or magnetic resonance diagnosis; (3) radiofrequency ablation or interstitial laser ablation technique; (4) English language; (5) population <10 patients; (6) follow-up ≥12 months; and (7) original research. Risk of bias was assessed with a modified Newcastle-Ottawa Scale.

RESULTS

Two hundred fourteen articles were initially found. After applying the criteria mentioned previously, 27 PTA articles concerning 1,772 patients were chosen for inclusion. No exclusions were made due to risk of bias.

CONCLUSION

The investigators proved the long-term efficacy and superiority of PTA for OO compared with other techniques. In 5% of patients, however, the technique failed, and the researchers did not offer detailed exhaustive explanations. Future clinical trials for OO ablation should consider reporting essential procedure details and follow-up findings to allow for a meta-analysis. We provide both recommended standards for future reporting and suggestions for the prevention of recurrence.

Gamma probe guided surgery for osteoid osteoma: is there any additive value of quantitative bone scintigraphy?

OBJECTIVE

The aim of this study is to evaluate the efficiency of gamma probe guided osteoid osteoma surgery and the applicability of quantitative analyses obtained from preoperative bone scan images.

MATERIAL AND METHODS

This study involved 12 osteoid osteoma patients who were treated with gamma probe guided surgery after preoperative bone scan. The calculated contrast ratios between nidus and adjacent healthy bone from preoperative bone scan and the calculated percentages of count reduction after resection of nidus during intraoperative gamma probe application were compared. Patients were followed up for any recurrence or complications.

RESULTS

The mean contrast ratio between nidus and adjacent healthy bone calculated from preoperative bone scan was 43.6% (range 33-53%). Following the nidus excision, an average of 55.8% (range 28-73%) count reduction was estimated with gamma probe in the tumor area. There was no correlation between preoperative scintigraphic contrast ratio and intraoperative gamma probe count reduction ratio (r = 0.46, p = 0.13). Complete cure was achieved in 11 (92%) patients with single operation, during the postoperative follow up period. None of the patients had any major or minor complications during or after the surgery.

CONCLUSIONS

Due to high clinical success and low complication rate in osteoid osteoma surgery, gamma probe application is an effective and safe method that should be used more extensively in daily practice.

Contrast media-doped hydrodissection during thermal ablation: optimizing contrast media concentration for improved visibility on CT images

OBJECTIVE

The purpose of this study is to determine a concentration of iodinated contrast media in saline and 5% dextrose in water (D5W) for organ hydrodissection, a technique used to physically separate and protect tissues adjacent to thermal ablations.

MATERIALS AND METHODS

A total of 28 samples were prepared from 1:1000-1:1 iohexol or iothalamate meglumine contrast media in either normal saline or D5W. Samples alone or juxtaposed with a homogeneous liver-mimicking phantom were imaged by CT using 80-120 kVp and 10-300 mAs. Mean CT numbers and noise were measured from the fluid, background air, phantom adjacent to the fluid, and phantom distant from the fluid. Visibility was determined from the contrast-to-noise ratio between the fluid and phantom, whereas streaking artifact was quantified by relative noise in the phantom. Measures were individually fit using multiple linear regression to determine an optimal contrast-to-fluid ratio for increased visualization without streaking. Contrast media- and blood-doped saline and D5W were also tested to determine whether such doping altered their electrical conductivity.

RESULTS

Iohexol concentration most influenced CT number; volumetric ratios of 1:1000-1:1 produced 20 HU to over 3000 HU. CT numbers were weakly dependent on x-ray tube voltage, whereas contrast-to-noise ratio and streaking artifacts were somewhat dependent on tube output. An optimal ratio of iohexol in fluid was determined to be 1:50. There was no significant difference between the electrical impedances of doped and pure saline or D5W (p > 0.5, all cases).

CONCLUSION

A 1:50 ratio of iohexol in saline or D5W provides an optimal combination of increased visibility on CT without streaking artifacts.

OSTEOID OSTEOMA IN THE ILIAC BONE: REPORT ON TWO CASES

Osteoid osteoma is a benign bone tumor that generally presents with nighttime pain among young adults and is relieved by rest and salicylates. It can affect any bone, but occurrences in the iliac are unusual. The authors describe two cases of intramedullary osteoid osteoma next to the sacroiliac joint, with symptoms that simulated sciatic pain. The cases were diagnosed late, although the initial radiographs showed sclerotic lesions in both cases. The diagnosis was confirmed by means of CT scan and the nidus was excised surgically through en bloc resection. The definitive diagnosis was given by means of histopathological examination. Over long-term follow-up, both cases remained asymptomatic and complete bone remodeling at the surgical site was observed. The authors highlight the typical characteristics of the tumor, the unusual location, the differential diagnosis and the treatment.

Particular imaging features and customized thermal ablation treatment for intramedullary osteoid osteoma in pediatric patients

OBJECTIVE

To report on the particular imaging features and high success rate of cold mode radio-frequency thermal ablation (RFTA) as the treatment of choice for intramedullary osteoid osteoma.

MATERIALS AND METHODS

The study population consisted of 51 patients (39 males, 12 females; mean age 7.2 years; 11 patients under 6 years of age, including 7 males and 4 females) who underwent RFTA for osteoid osteoma and were retrospectively observed. The affected sites were the tibia (n = 22, 43%), femur (n = 13, 25%), pelvis (n = 5, 10%), anklebone (n = 3, 6%), humerus (n = 2, 4%), sacrum (n = 2, 4%), heel, radium, patella ,and rib (n = 1, 2%), respectively. Three patients had tibial intramedullary osteoid osteoma (14% of the tibial lesions, 6% of all cases). Cold mode RFTA was performed for these three patients to obtain a large ablation area without positioning two probes. The noncooled mode was used to treat cortical and subperiosteal lesions.

RESULTS

Following RFTA, all patients were pain-free and in good clinical condition. In the intramedullary osteoid osteoma group, no recurrences were observed during the 24-month follow-up period, but one patient, who was affected by cortical osteoid osteoma, required two RFTA treatments to heal completely.

CONCLUSION

Children less than 6 years of age with recurrent nocturnal pain and limb swelling should be investigated for intramedullary osteoid osteoma. Once confirmed, CT-guided RFTA should be the first treatment for intramedullary osteoid osteomas because of the high success rate and reduced invasivity, especially with cold mode RFTA. The outcome is related to the disappearance of pain, and the efficacy may be checked shortly after treatment with MR imaging to evaluate the absence of lesion in the ablation area.

CT-guided percutaneous cryoablation of osteoid osteoma in children: an initial study

OBJECTIVE

The purpose of this study was to evaluate the safety and efficacy of CT-guided percutaneous cryoablation for osteoid osteoma in children.

MATERIALS AND METHODS

This study was approved by the institutional ethics committee. From January 2007 to July 2008, six children (four boys, two girls, mean age 12.6 years old) with osteoid osteoma were treated with CT-guided percutaneous cryoablation. The procedures were carried out under conscious sedation and local anesthesia. CT guidance was used for procedural planning, instrument guidance, and monitoring. An argon-based cryoablation system was used. Each cryoablation included two freezing-thawing cycles. Follow-up was performed to assess technical and clinical outcome for a minimum of 12 months. A visual analog scale (VAS) was used to assess severity of pain pre- and post-procedure, and mean VAS for the group was compared pre- and post-procedure with a t-test. The mean clinical follow-up period was 28.7 months (ranging from 18 to 36 months).

RESULTS

Cryoablation was technically and clinically successful for all patients. No major immediate or delayed complications were observed. Significant pain relief (P <0.05) was observed in all patients after operation. Mean VAS were 6.57 ± 0.55 pre-procedure and 0.57 ± 0.10 1 month post-procedure. Patients were allowed to fully bear their weight and function without limitation within 3 days after the procedure. Pain recurrence was not observed in any patient.

CONCLUSION

Percutaneous cryoablation is safe and effective for the treatment of osteoid osteomas in children. Notably, this procedure can be accomplished without general anesthesia.

Osteoid osteoma of the great toe

Osteoid osteoma is a relatively common osteoblastic lesion of benign skeletal neoplasms and occurs most commonly in the cortex of long bones, especially the femur and the tibia. Radiological characteristics are a nidus that appears as a small, relatively radiolucent zone within an area of extensive reactive sclerosis. Clinically, the lesion presents with increasing pain, is worse at night, and is relived by nonsteroidal anti-inflammatory drugs (NSAIDs). Osteoid osteomas involving the phalanges of the toes are uncommon, and its accurate preoperative diagnosis is difficult due to the unique clinical and radiological features. The features in the phalanx of the toe are soft tissue swelling and a nidus frequently located in the cancellous without osteosclerosis. This article presents a case of a 22-year-old man with osteoid osteoma in his distal phalanx of the hallux. A needle biopsy of his great toe revealed a small number of bacteria, so he was initially treated for osteomyelitis but with unsatisfactory results. The particular characteristics of clinical and imaging findings supported a diagnosis of osteoid osteoma in the distal phalanx of the hallux. After surgical removal of the tumor, his symptoms resolved. The pathological examination confirmed the suspected diagnosis. In a patient with chronic foot pain that changes to become nocturnal and disappears with NSAID administration, it is important to include osteoid osteoma as a differential diagnosis. A detailed assessment of both clinical and radiological features can lead to the correct diagnosis, which must be confirmed with histopathological examination to ensure adequate excision.

Percutaneous radiofrequency ablation of osteoid osteoma using cool-tip electrodes without the cooling system

PURPOSE

The aim of this study was to evaluate the efficacy of percutaneous radiofrequency ablation (RFA) for osteoid osteoma (OO) using cool-tip electrodes without the cooling system.

MATERIALS AND METHODS

A total of 17 patients (13 males, 4 females; mean age 19.1 years; range 7-49 years) with OO (tibia, n = 7; femur, n = 5; acetabulum, n = 2; radius, n = 1; talus, n = 1; lumbar spine, n = 1) underwent RFA. Using a cool-tip electrode without the cooling system, the lesion was heated to 90°C for 4 or 5 min. Procedures were considered technically successful if the electrode was placed into the nidus and the target temperature was reached and maintained for at least 4 min. Clinical success of the treatment was defined as complete or partial pain relief after RFA.

RESULTS

All procedures were considered technically successful, although two patients encountered complications (pes equinus contracture, skin burn). Altogether, 16 of the 17 patients (94.1%) achieved complete or partial pain relief after primary RFA. Two patients had pain recurrence, with one of them treated successfully with a second RFA. The overall clinical success rate was 88.2%. Histological findings confirmed the presence of OO in 13 patients (76.5%).

CONCLUSION

Percutaneous RFA of OO using cool-tip electrodes without the cooling system is a safe, effective procedure.

Radiofrequency ablation of osteoid osteoma in atypical locations: a case series

BACKGROUND

Osteoid osteoma has a nidus surrounded by sclerotic bone with a size usually less than 20 mm. Its diagnosis is made on typical presentation of nocturnal pain and imaging findings. Excision of the niduses, which are often small and difficult to precisely identify, sometimes may result in resection of surrounding normal bone. Minimally invasive percutaneous treatments have been used to try to minimize resection of normal bone. Although minimally invasive radiofrequency ablation generally relieves pain, its ability to relieve pain is less well known in locations other than lower extremity long bones.

QUESTIONS/PURPOSES

We determined the pain relief and complication rates after radiofrequency ablation of osteoid osteomas presenting in atypical locations and followed patients to assess possible recurrence or late complications.

PATIENTS AND METHODS

We retrospectively reviewed 21 patients with osteoid osteomas in unusual locations (eg, hip, radioulnar joint, and proximal phalanx) in whom we used radiofrequency ablation. Postoperative activities were not restricted for any of the patients. We assessed the time for patients to become symptom free, their activity status, and possible recurrence or complications. The minimum clinical followup was 12 months (mean, 27.8 months; range, 12-37 months).

RESULTS

All patients became symptom free within 24 hours to 1 week. During followup, none of the patients experienced recurrence or any major complications.

CONCLUSIONS

Radiofrequency ablation for osteoid osteomas in unusual locations reliably relieves pain with few complications and recurrences at short-term followup.

LEVEL OF EVIDENCE

Level IV, case series. See Guidelines for Authors for a complete description of level of evidence.

Histological evaluation of drill fragments obtained during osteoid osteoma radiofrequency ablation

OBJECTIVE

Osteoid osteoma (OO) is a benign bone tumor diagnosed mainly on the basis of the patient's history and radiological data. Histological evaluation may not be available before treatment. The aim of this study was to assess the diagnostic value of a histological evaluation of the bone fragments obtained during radiofrequency ablation (RFA).

MATERIALS AND METHODS

During a 2-year period, 39 patients diagnosed clinically with OO were entered into this study. The procedure was performed under computed tomography (CT) guidance. An 11-gauge needle was initially placed as a coaxial guide. After drill removal, RFA was performed. Bone fragments collected from the drill were examined by two experienced pathologists, independently.

RESULTS

There was strong association between pathologists' reports (P <0.001). In 27 cases (69.2%) this diagnosis was confirmed pathologically. No significant relationship was found between nidus diameter and positive histological findings (P = 0.35).

CONCLUSION

Histological confirmation of OO based on drill fragments is similarly frequent as previously reported for standard bone biopsy.

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

OBJECTIVE

To evaluate the efficacy of computed tomography (CT)-guided radiofrequency (RF) ablation for the treatment of osteoid osteomas in common and in technically challenging locations.

MATERIALS AND METHODS

Twenty-three patients with osteoid osteomas in common (nine cases) and technically challenging [14 cases: intra-articular (n = 7), spinal (n = 5), metaphyseal (n = 2)] positions were treated with CT-guided RF ablation. Therapy was performed under conscious sedation with a seven-array expandable RF electrode for 8-10 min at 80-110 degrees C and power of 90-110 W. The patients went home under instruction. A brief pain inventory (BPI) score was calculated before and after (1 day, 4 weeks, 6 months and 1 year) treatment.

RESULTS

All procedures were technically successful. Primary clinical success was 91.3% (21 of total 23 patients), despite the lesions' locations. BPI score was dramatically reduced after the procedure, and the decrease in BPI score was significant (P < 0.001, paired t-test; n-1 = 22) for all periods during follow up. Two patients had persistent pain after 1 month and were treated successfully with a second procedure (secondary success rate 100%). No immediate or delayed complications were observed.

CONCLUSION

CT-guided RF ablation is safe and highly effective for treatment of osteoid osteomas, even in technically difficult positions.

IR challenges in the MSK system

As the capability of medical imaging equipment improves, and relatively new modalities such as cone beam CT with guidance becomes more widely available, the range and complexity of image guided orthopedic procedures continues to expand. Challenges include the predictable technical and anatomic issues, as well as the complex operational and political issues associated with moving and integrating an interventional radiology service into the traditional operating room environment.

Osteoid osteoma of the femur in a 7-month-old infant treated with radiofrequency ablation

Osteoid osteoma occurs most commonly in children, adolescents, and young adults between the ages of 5 and 30 years. In the preschool age group, it is quite uncommon, accounting for only 3-8% of all osteoid osteoma cases. We report a case of osteoid osteoma in a 7-month-old infant, who presented with decreased use of the right lower extremity due to pain. Magnetic resonance imaging (MRI) showed an atypical appearance. A biopsy of the lesion, with histopathological examination, confirmed the diagnosis of osteoid osteoma. Radiofrequency ablation (RFA) of the nidus under computed tomography (CT) guidance was performed. The patient developed a recurrence after 3 months, which was treated with a second RFA. On subsequent follow-up, the infant did not show signs of pain after 1 month. In summary, this case report shows that osteoid osteoma can present in early infancy and can be successfully treated with RFA at this age, however, recurrence after the procedure can occur and close follow-up is recommended.

Hip fracture after radiofrequency ablation therapy for bone tumors: two case reports

Radiofrequency ablation (RFA) has become a valuable therapeutic modality in cancer treatment over the last decade. In orthopedic surgery, RFA is used for the treatment of benign bone tumors and bone metastases. Complications are rare and, to our knowledge, bone fracture as a complication due solely to RFA has not been reported to date. In this report we describe two patients with a fracture in the calcar region of the femur as a complication of RFA treatment for bone malignancies. Since RFA is applied increasingly often, it is important to report this risk of fracture as a complication of treatment of lesions in the femoral calcar.

The use of radiofrequency ablation in the treatment of musculoskeletal tumors

Musculoskeletal tumors, both primary neoplasms and metastatic lesions, present a therapeutic challenge for the physician who wishes to provide palliative pain relief using the least invasive approach. The increasing sophistication of imaging modalities such as CT in precisely localizing neoplasm, coupled with the widespread use of radiofrequency ablation (RFA) for treatment of other types of tumor, has generated interest in using RFA to treat musculoskeletal tumors. Primary bone tumors (eg, osteoid osteoma) and metastatic bone tumors have been successfully treated with RFA. Success rates with RFA are equal to those with standard surgical curettage, but RFA has the advantage of decreased surgical morbidity. The procedure is relatively safe, is well-tolerated by the patient, and typically can be performed on an outpatient basis. The most common serious complication reported is localized skin necrosis, which occurs rarely. RFA appears to be a viable minimally invasive approach for palliative treatment of selected bone tumors.

Subchondral osteoid osteoma of the glenoid

Osteoid osteoma of the scapula is a rare benign lesion. This is a case report of a subchondral osteoid osteoma that involved the anterior rim of glenoid. Surgical approach in this atypical area may seem difficult. The excision of the lesion and grafting was performed by a deltopectoral approach. One year after the surgery, the patient remains pain free and has full range of motion with no recurrence of the tumour.