Intralesional Ethibloc injections in primary aneurysmal bone cysts: an efficient and safe treatment

Pathological Fractures in Aneurysmal Bone Cysts: A Systematic Review

Background: Aneurysmal bone cysts (ABCs) are osteolytic, non-malignant, vascular lesions of the bone. Pathological fractures can be a manifestation of the ABCs, which occur in about 8% of ABCs. Different treatments have been described in the literature, but, nowadays, an optimal management of the pathological fractures in patients with ABCs is still a matter of debate and there are no standard guidelines for treatment nor any shared indication about the best surgical intervention. The aim of our study is to review the current literature available on this matter exploring and confronting different surgical treatments for pathological fractures in ABC in order to clarify the surgical approach to these patients. Methods: A systematic review of the literature indexed in PubMed, MEDLINE, and Cochrane Library databases was carried out. The Preferred Reporting Items for Systematically Reviews and Meta-Analyses (PRISMA) were followed. Results: A total of 37 articles were relevant and were finally included in the study. In total, we reached a population of 140 patients. Of the 140 patients included in the review, 124 patients (88.6%) underwent curettage surgery, 15 patients (10.7%) underwent en bloc resection surgery. A total of 47% of patients (70) underwent synthesis surgery with a plate, screw, nail, or external fixator. Adjuvant treatments were used in 8.6% of patients (12). Complications involved 20.7% of the patients (29). Conclusions: In conclusion, the treatment of pathological fractures in aneurysmal bone cysts requires careful patient assessment, considering factors such as age, the presence of open growth plates, the location of the lesion, and the surgeon's expertise.

Single dose intralesional doxycycline foam infusion promotes bone growth and resolution of an odontoid aneurysmal bone cyst

Background

Aneurysmal bone cysts (ABCs) are locally invasive bone tumors that most commonly arise in long bone metaphyses, the vertebral column, and pelvis, often presenting in the second decade of life. ABCs can be treated with resection, radiation, arterial embolization, and intralesional curettage. More recently intralesional doxycycline foam injections, which appear to act through the inhibition of matrix metalloproteinases and angiogenesis, have been used successfully, although multiple treatments are often required with this approach.

Case Description

A 13-year-old male with an incidentally discovered ABC filling much of the odontoid process but not violating the native odontoid cortex was treated with a single intralesional doxycycline foam injection delivered through a transoral approach with an excellent radiographic result. After placing a Crowe-Davis retractor, a transoral exposure of the odontoid process was performed with neuronavigation guidance. A fluoroscopy-guided Jamshidi needle biopsy was performed and via the needle doxycycline foam (2 mL 50 mg/mL doxycycline, 2 mL 25% albumin, and 1 mL Isovue 370 mixed with 5 mL of air) was infused, filling the cystic cavities of the odontoid process. The patient tolerated the operation well. Two months postoperatively, a computed tomography (CT) scan demonstrated a decrease in the size of the lesion with substantial new bone formation. Repeat CT at 6 months showed no residual cystic lucency, formation of dense new bone, and only minimal irregularity of the cortex at the prior needle biopsy site.

Conclusion

This case illustrates that the use of doxycycline foam can be an excellent option when managing ABCs that cannot be resected without incurring significant morbidity.

Treatment of an aneurysmal bone cyst in a young dog: A case report

Background

An aneurysmal bone cyst (ABC) is a rare benign lytic lesion affecting the medullary canal of long bones. It has been widely reported in human medicine, but rarely described in domestic animals.

Objective

To report the surgical treatment and long term follow‐up of a dog affected by ABC.

Methods

An 8‐month‐old, intact female Weimaraner was presented with lameness affecting the left front limb and progressive swelling of the mid‐distal radius. Survey radiographs revealed a mid‐distal diaphyseal radial lesion. Fine needle aspirates, biopsy, CT scan and histopathology results supported the diagnosis of ABC. Treatment consisted of partial corticotomy of the affected radius, filling of the cystic cavity with demineralised bone matrix and autologous bone graft and stabilisation using lag screws and a neutralisation plate.

Results

The long‐term follow‐up, at 36 post‐operative months, showed no recurrence of the cyst and bone modelling. Comparing preoperative radiographs with those at 36 months, bone modelling reduced the radial area by 23.3% in the craniocaudal radiographic view and 30% in the mediolateral projection.

Conclusions

This treatment was sucessful in the case here described, with a 3 years follow‐up.

Current strategies for the treatment of solitary and aneurysmal bone cysts: A review of the literature

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SBCs can mostly be treated conservatively.

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In ABCs a biopsy is compulsory.

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ABCs can be treated by polidocanol instillations adequately.

This review of the literature aims to compare the etiology, the pathogenesis, the clinical diagnostics and the relevant treatment options of two different types of cystic bone lesions: the solitary bone cyst (SBC) and the aneurysmal bone cyst (ABC). Whereas the clinical symptoms and the radiographic appearance can be similar, the diagnostic pathway and the treatment options are clearly different.

The solitary bone cyst (SBC) represents a tumor-like bone lesion, occurring most frequently in the humerus and femur in children and adolescents. Pain caused by intercurrent pathological fractures is often the first symptom, and up to 87% of the cysts are associated with pathological fractures. In the majority of cases SBCs can be treated conservatively, especially in the upper extremity. However, if a fracture is completely dislocated, joint affecting, unstable or open, surgical treatment is necessary. Pain under weight bearing or regaining the ability to mobilize after fracture timely can necessitate surgical treatment in SBCs affecting the lower extremity. Spontaneous resolution can be seen in rare cases.

The aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor that occurs in childhood and early adulthood. It usually affects the metaphysis of long bones but can also occur in the spine or the pelvis. ABC can be primary but also secondary to other bone pathologies. The diagnosis has to be confirmed by biopsy and histopathological examinations. With cytogenetic studies and the detection of specific translocations of the ubiquitin-specific protease (USP) 6 gene primary ABCs can be differentiated from secondary ABCs and other bone lesions. Among various modalities of treatment i.e. en bloc resection, intralesional curettage with adjuvants, embolization or the systemic application of denosumab, intralesional sclerotherapy using polidocanol is an effective and minimally invasive treatment of primary ABCs.

A Rare Case of Aneurysmal Bone Cyst - Navicular Bone Treated by Intralesional Sclerotherapy Agent Polidocanol

Introduction:

Aneurysmal bone cyst (ABC) is an intraosseous arteriovenous malformation, usually treated by surgical excision but with higher recurrence rates. The occurrence of this lesion in navicular bone is a rare entity. Repetitive sclerotherapy using 3% polidocanol is a minimally invasive, safer method of treatment for ABCs.

Methods:

A patient of ABC of the navicular bone precisely diagnosed through X-ray, MRI, and biopsy was given periodic injections of 4 ml of 3% polidocanol under aseptic precautions from April 2018 to July 2018. A total of four injections given at an interval of 1 month.

Results:

Regular follow-up done for 1 year. At the end of all the four injections, the lesion healed completely with a relief in presenting symptoms. No complications were reported. At 3 months post-therapy, the patient was able to walk without pain. After 1 year of follow-up, the patient was symptom-free with no signs of recurrence.

Conclusion:

Surgical resection/curettage has higher chances of recurrence; therefore, usage of intralesional sclerotherapy agent polidocanol should be considered the treatment of choice in the lesions smaller than 5 cm.

Musculoskeletal Interventional Radiology in the Pediatric Population: State of the Art

Interventional radiology procedures have been proven to be as effective as traditional surgery but usually are characterized by lower morbidity rates. In this article, the most diffuse IR treatments for pediatric lesions are reviewed with the aim of describing main advantages and drawbacks. Ablation procedures (in particular RFA and MRgFUS) are widely used for the management of osteoid osteoma and osteoblastoma whereas intracystic injection of methylprednisolone acetate is performed for simple bone cysts. Sclerosing agents and where possible, selective arterial embolization are used for treatment of aneurysmal bone cysts and other vascular malformations. In the management of malignant muscoloskeletal tumors, the role interventional radiology is mainly represented by percutaneous biopsies, and by adiuvant selective embolizations in presence of hypervascular lesions to be submitted to surgery.

Primary Aneurysmal Bone Cyst and Its Recent Treatment Options: A Comparative Review of 74 Cases

(1) Background: An aneurysmal bone cyst (ABC) is a benign, locally aggressive tumor. Different treatment modalities are described in the literature i.e., en bloc resection, intralesional curettage and percutaneous sclerotherapy. (2) Methods: This single-center study is a review of 74 patients with primary ABCs who underwent a surgical treatment or polidocanol instillation. Cyst volume measurements using MRI and conventional radiographs are compared. (3) Results: The mean pre-interventional MRI-based cyst volume was 44.07 cm³ and the mean radiographic volume was 27.27 cm³. The recurrence rate after intralesional curettage with the need for further treatment was 38.2% (13/34). The instillation of polidocanol showed a significant reduction of the initial cyst volume (p < 0.001) but a persistent disease occurred in 29/32 cases (90.6%). In 10 of these 29 cases (34.5%) further treatment was necessary. After en bloc resection (eight cases) a local recurrence occurred in two cases (25%), in one case with the need for further treatment. (4) Conclusions: MRI scans are superior to biplanar radiographs in the examination of ABCs. Sequential percutaneous instillations of polidocanol are equally effective in the therapy of primary ABCs compared to intralesional curettage. However, several instillations have to be expected. In a considerable number of cases, a conversion to intralesional curettage or en bloc resection may be necessary.

Efficacy of treatment interventions for primary aneurysmal bone cysts: a systematic review

AIMS

Aneurysmal bone cysts (ABCs) are locally aggressive lesions typically found in the long bones of children and adolescents. A variety of management strategies have been reported to be effective in the treatment of these lesions. The purpose of this review was to assess the effectiveness of current strategies for the management of primary ABCs of the long bones.

METHODS

A systematic review of the published literature was performed to identify all articles relating to the management of primary ABCs. Studies required a minimum 12-month follow-up and case series reporting on under ten participants were not included.

RESULTS

A total of 28 articles meeting the eligibility criteria were included in this review, and all but one were retrospective in design. Due to heterogeneity in study design, treatment, and outcome reporting, data synthesis and group comparison was not possible. The most common treatment option reported on was surgical curettage with or without a form of adjuvant therapy, followed by injection-based therapies. Of the 594 patients treated with curettage across 17 studies, 86 (14.4%) failed to heal or experienced a recurrence. Similar outcomes were reported for 57 (14.70%) of the 387 patients treated with injection therapy across 12 studies. Only one study directly compared curettage with injection therapy (polidocanol), randomizing 94 patients into both treatment groups. This study was at risk of bias and provided low-quality evidence of a lack of difference between the two interventions, reporting success rates of 93.3% and 84.8% for injection and surgical treatment groups, respectively.

CONCLUSION

While both surgery and sclerotherapy are widely implemented for treatment of ABCs, there is currently no good quality evidence to support the use of one option over the other. There is a need for prospective multicentre randomized controlled trials (RCTs) on interventions for the treatment of ABCs. Cite this article: Bone Jt Open 2021;2(2):125-133.

Percutaneous alcohol-based sclerotherapy in aneurysmal bone cyst in children and adolescents

INTRODUCTION

Aneurysmal bone cyst (ABC) is a benign bone lesion of childhood and adolescence. It can be locally aggressive, with risk of fracture. Management is controversial. The aim of the present study was to assess the efficacy, simplicity and tolerance of percutaneous alcohol-bases sclerotherapy in ABC.

HYPOTHESIS

Alcohol-based sclerotherapy for ABC under radiographic control is safe and effective.

MATERIAL AND METHODS

A single-center retrospective study for the period 2008-2016 included all of the 55 ABCs, in 54 patients, confirmed on pathology and treated by alcohol-based sclerotherapy under radiographic control. Mean age at diagnosis was 9.6 years. ABC involved the humerus in 30 cases (54%), tibia in 7 (13%) and femur in 5 (9%). Mean follow-up was 50.9 months (range, 16-117 months). Mean number of applications was 1.7 (range, 1-4). Results were assessed clinically (pain, return to sport, limb length and alignment, revision surgery) and radiologically. The main endpoint was lesion volume reduction. The secondary endpoint was failure, defined by open revision surgery or pain preventing return to a sports activity.

RESULTS

Clinical progression was favorable in 36 patients (67%), and radiological progression in 45 (85%). Only 1 cyst required secondary resection. One patient experienced spontaneously resolving intraoperative bradycardia. Male gender and young age emerged as factors for poorer response.

DISCUSSION

ABC management in children can be made difficult by lesion size, aggressiveness, location, proximity to the growth plate and small bone stock. Alcohol-based sclerotherapy is simple, reliable and effective in childhood ABC, and may be a first-line attitude, avoiding recourse to invasive surgery.

LEVEL OF EVIDENCE

IV, retrospective study.

Validating the management paradigm for pediatric spinal aneurysmal bone cysts to optimize long-term outcomes: an institutional experience

BACKGROUND

The optimal clinical management and outcomes of rare pediatric spinal aneurysmal bone cysts (spABC) is largely anecdotal. Current practice is based on bigger adult series, although given the disparities in spine growth of adults versus children, what impact this difference may have on long-term outcomes has yet to be substantiated. Correspondingly, the aim of this study was to describe the clinical course of all pediatric spABC cases managed at our institution to better understand this.

METHODS

A retrospective cohort study of all pediatric spABC cases presenting to our institution between 1993 and 2017 was performed using a predetermined set of selection criteria. Primary outcomes of interest were treatment modalities and their outcomes, recurrence status, and functional status.

RESULTS

A total of 24 pediatric spABC cases satisfied all criteria. Median age of diagnosis was 13.5 years, with 15 females and 9 males. Radicular pain was the presenting symptom in 21 (88%) cases. Diagnostic biopsy was pursued in 9 (38%) cases, pre-operative embolization in 8 (33%) cases, surgical intervention in 23 (96%) cases, and sclerotherapy in 2 (8%) cases. In terms of surgery, there were no intraoperative complications, and gross total resection (GTR) was achieved in 14 of the 23 (61%) cases. Overall, there were 5 (21%) cases which experienced recurrence by a median time of 8 months after initial surgery, all of which had initial subtotal resection. Median follow-up was 5 years, by which all patients demonstrated excellent functional status.

CONCLUSIONS

There are a number of feasible therapeutic modalities and combinations that can be utilized to maximize control of pediatric spABCs and optimize long-term function similar to that of adults, irrespective of developing versus developed spines. The incidence of recurrence is not negligible, and therefore, rigorous long-term surveillance is highly encouraged, particularly within the first post-operative year following mono-modal non-GTR treatment.

French Multidisciplinary Approach for the Treatment of MSK Tumors

Several interventional treatments have recently been integrated into the therapeutic armamentarium available for the treatment of bone tumors. In some scenarios (e.g., osteoid osteoma), interventional treatments represent the sole and definitive applied treatment. Due to the absence of widely shared protocols and the complex multivariate scenarios underlying the clinical presentation of the remaining bone tumors including metastases, therapeutic strategies derived from a multidisciplinary tumor board are essential to provide effective treatments tailored to each patient. In the present review, we present the multidisciplinary therapeutic strategies commonly adopted for the most frequent bone tumors.

Bone Marrow Concentrate in the Treatment of Aneurysmal Bone Cysts: A Case Series Study

Introduction

A recent attractive option regarding mesenchymal stem cells (MSC) application is the treatment of bone cystic lesions and in particular aneurysmal bone cysts (ABC), in order to stimulate intrinsic healing. We performed a retrospective evaluation of the results obtained at our institution.

Methods

The study group consisted of 46 cases with an average follow-up of 33 months. Forty-two patients underwent percutaneous treatment as the first approach; four patients had curettage as first treatment. In all cases, autologous bone marrow concentrate (BMC) was associated too. The healing status was followed up through a plain radiograph 45 days and 2 months after the procedure. Results and Conclusions. At the final follow-up, thirty-six patients healed with a Neer type II aspect, nine healed with a type I aspect, and one patient was not classified having total hip arthroplasty. Bone marrow concentrate is easy to obtain and to manipulate and can be immediately available in a clinical setting. We can assert that the use of BMC must be encouraged being harmless and having an unquestionable high osteogenic and healing potential in bone defects.

Percutaneous Treatments of Benign Bone Tumors

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

Sclerotherapy using Surgiflo and alcohol: a new alternative for the treatment of aneurysmal bone cysts

PURPOSE

This study aims to review the results of sclerotherapy using Surgiflo in addition to alcohol in primary aneurysmal bone cysts (ABC).

METHODS

A total of 16 consecutive patients with histologically confirmed diagnosis of primary ABC were treated by percutaneous Surgiflo and alcohol injection at our institution. Clinical follow-up included the assessment of pain, swelling, limping and functional impairment. Radiological parameters included tumour volume, physis-cyst distance, thickness of cyst cortex, and presence of intracystic septations. Mean follow-up was 35,6 months (24-71 months). Treatment was considered successful when the cyst volume decreased by a minimum of 10%, the bone cortex became thicker, and the distance to physis increased.

RESULTS

Mean age at presentation was 9.5 years (5.16-13.84 years). All ABC's were primary and all patients underwent a single Surgiflo and alcohol session except for two (12.5%) who required a second session. All patients had a good clinical result at final follow-up. Satisfactory cyst healing was achieved in 11 cases according to radiological parameters. Tumour volume decreased from a mean of 122 cm³ (111 to 133) before injection to 86 cm³ (76 to 96) at last follow-up (p < 0.01). Physis-cyst distance increased from a mean of 1 cm (0.1 to 2) to 2.1 cm (0.5 to 4) at last follow-up (p < 0.01). Cortical thickness improved from 1 mm (0.5 to 1.5) to 2 mm (1 to 3.5) at last follow-up (p < 0.01).There were no treatment related complications. Surgery was performed in one patient having a C3 vertebra ABC after developing quadriparesis due to tumour progression.

CONCLUSION

Sclerotherapy using Surgiflo and alcohol may be used as an efficient, safe and minimally invasive alternative for the treatment of primary ABCs.

Treatment of Aneurysmal Bone Cysts with Bioactive Glass in Children

Background and Aims:

Aneurysmal bone cysts represent about 1% of primary bone tumors. The standard treatment is curettage, followed by local adjuvant treatments and bone grafting. The problem is the high recurrence rate. The purpose of this study was to evaluate retrospectively the use of bioactive glass as a filling material in the treatment of aneurysmatic bone cysts in children.

Material and Methods:

A total of 18 consecutive children (mean 11.3 years at surgery; 10 males; 11 lower, 6 upper limb, 1 pelvis; 15 with primary surgery) with histologically proven primary aneurysmal bone cysts operated with curettage and bioactive glass filling between 2008 and 2013 were evaluated after a mean follow-up of 2.0 years (range, 0.7–5.1 years).

Results:

Two (11%) patients showed evidence of aneurysmal bone cyst recurrence and both have been re-operated for recurrence. Bone remodeling was noted in all patients with remaining growth and no growth plate disturbances were recorded. Two patients needed allogeneic blood transfusion. No intraoperative or postoperative complications were recorded.

Conclusion:

We conclude that bioactive glass is a suitable filling material for children with primary aneurysmal bone cyst. Bioactive glass did not affect bone growth and no side effects were reported.

Efficacy and Safety of Selective Arterial Embolization in the Treatment of Aneurysmal Bone Cyst of the Mobile Spine: A Retrospective Observational Study

STUDY DESIGN

A retrospective observational study.

OBJECTIVE

Our aim is to define the efficacy and safety of serial selective arterial embolization (SAE) in the treatment of aneurysmal bone cysts (ABCs), to explore potential treatment alternatives, and to define a therapeutic algorithm.

SUMMARY OF BACKGROUND DATA

ABC is a benign lesion with an unpredictable behavior. Its treatment is challenging especially in poorly accessible surgical areas, such as spine and pelvis. Currently, the first-line treatment of ABC is repeated SAE until healing. Other options have been used with variable success rates.

METHODS

From January 2004 to September 2015, 23 patients affected by ABC of the mobile spine have been treated with SAE and prospectively followed up by computed tomographic scan and magnetic resonance imaging. Signs of neurological deficit, complications, healing of the lesion, and clinical outcomes were registered.Signs of healing are defined as peripheral sclerotic bone rim formation, decrease of the ABC mass, disappearance of the double content image, and bone formation inside the ABC mass, associated with remission of pain.

RESULTS

Twenty-three patients underwent SAE according to the protocol. Seventeen patients have healed. The number of procedures necessary to obtain healing (clinical and radiographic) varied from 1 to 10. No complication occurred during the procedure. Follow-up time ranged from 5 to 120 months after the last angiographic procedure. All 17 patients had complete relief of pain symptoms. Six patients did not respond to SAE, presenting a progressive clinical and radiographic worsening, and underwent other medical or minimally invasive treatments.

CONCLUSION

Our study confirms the safety of SAE. The efficacy of the treatment was however lower than expected. SAE is indicated when pathological fracture or signs of cord damage are not detected. Infiltration with autologous bone marrow concentrate or administration of Denosumab is under investigation as alternative choices of treatment.

LEVEL OF EVIDENCE

4.

Current management of aneurysmal bone cysts

Aneurysmal bone cysts (ABCs) are benign bone lesions arising predominantly in the pediatric population that can cause local pain, swelling, and pathologic fracture. Primary lesions, which constitute roughly two thirds of all ABCs, are thought to be neoplastic in nature, with one third of ABCs arising secondary to other tumors. Diagnosis is made with various imaging modalities, which exhibit characteristic features such as "fluid-fluid levels," although biopsy is critical, as telangiectatic osteosarcoma cannot be excluded based on imaging alone. Currently, the standard of care and most widely employed treatment is intralesional curettage. However, tumor recurrence with curettage alone is common and has driven some to propose a multitude of adjuvants with varying efficacy and risk profiles. Historically, therapies such as en bloc resection or radiation therapy were utilized as an alternative to decrease the recurrence rate, but these therapies imposed high morbidity. As a result, modern techniques now seek to simultaneously reduce morbidity and recurrence, the pursuit of which has produced preliminary study into minimally invasive percutaneous treatments and medical management.

Pediatric aneurysmal bone cyst in the ischial region

Aneurysmal bone cyst (ABC) is an expanding osteolytic lesion. ABC represents 1% of all primary benign bone tumors, whereby 4-12% occur in the pelvis. The etiology of this disease remains vague. Aneurysmal bone cyst can exist either as primary bone lesion (70%) or as secondary lesion arising from another bone disorder (30%). Moreover, pelvic ABCs are characterized by their large size and high vascularity. We present a rare pediatric case with ABC involving the ischial region. A 5-year-old girl presented with left pelvic pain and limping for the past 6 months. Initial imaging showed an expansile lesion in the left ischium, and computed tomography guided biopsy showed giant cells in histopathology study with no evidence of metastasis. The patient underwent intraoperative frozen section followed by extensive intra-lesional bone excision. Bone curettage was pursued along with bone grafting. The case was successfully managed without postoperative complications after the 6-month follow-up period.

Aneurysmal bone cyst: A 19-case series managed by percutaneous sclerotherapy

INTRODUCTION

Sclerotherapy offers an alternative to surgery for the treatment of aneurysmal bone cyst (ABC). The main objective of the present study was to assess the radiological efficacy of sclerotherapy in terms of ossification on MRI. Secondary objectives were to assess clinical efficacy on pain evaluation and to analyze recurrence and complications according to type of sclerosing agent and intraoperative imaging technique.

MATERIALS AND METHODS

Between 2006 and 2014, 19 patients (7 females, 12 males, aged 3 to 17 years) with ABC treated by sclerotherapy were included. Six received Ethibloc(®), 9 Aetoxisclerol(®), 2 liquid absolute alcohol, and 2 absolute alcohol gel. Assessment used fluoroscopy in 17 cases and CT in 2. Ossification was assessed on MRI and pain on a visual analog scale and HEDEN score.

RESULTS

Ossification was complete in 11 cases (84.6%) and partial in 2 (15.4%). Eighteen patients (94.7%) were pain-free at 3 months. There was no recurrence, at a minimum 2 years' follow-up. One case of skin necrosis was observed, associated with use of liquid absolute alcohol; there was 1 case of arterial reflux of Ethibloc(®) under CT control.

DISCUSSION

Sclerotherapy enables minimally invasive treatment of lesions that are deep, difficult of access to surgery and potentially damaging. Use of absolute alcohol gel and fluoroscopic control seems to improve the risk/benefit ratio, limiting complications by vascular extravasation of the sclerosing agent, thanks to real-time visualization of diffusion. Its clinical and radiological efficacy makes sclerotherapy and alternative primary treatment choice in ABC.

LEVEL OF EVIDENCE

IV, retrospective study.

Percutaneous Doxycycline Treatment of Juxtaphyseal Aneurysmal Bone Cysts

BACKGROUND

A recurrence rate of 19% to 23% has been reported in juxtaphyseal aneurysmal bone cysts (ABC) without en bloc resection or amputation. No percutaneous surgical techniques or drug treatments have demonstrated consistent bone healing with normal physeal growth and a recurrence rate of <19%. Doxycycline has properties that may make it an appropriate agent for percutaneous treatment of juxtaphyseal ABC in skeletally immature patients.

METHODS

We retrospectively reviewed 16 patients who underwent percutaneous treatment of ABCs with doxycycline from 2006 to 2011. The mean age was 7.1 years (range, 2 to 15 y). There were 16 treatment locations: humerus (9), tibia (3), fibula (2), femur (1), and ulna (1). Sixteen patients completed treatment involving 102 treatment sessions (2 to 14 sessions per patient). Treatment response was evaluated radiographically by measuring the lytic component, thickness of involved cortex, and signs of bony remodeling, and evidence of physeal growth arrest. Recurrence was indicated by new areas of lytic destruction after completion of treatment. The minimum follow-up was 18 months (mean, 39 mo).

RESULTS

All 16 patients demonstrated reduction in lytic destruction, bony healing, and bony remodeling. One patient demonstrated recurrent minimal lytic destruction after 20 months of observation. Seven patients (7/16, 44%) demonstrated physeal ABC involvement; 5 of 7 patients healed with a physeal bone bridge, all ≤15% of the physeal surface area, 1 with mild central physeal deformity. All patients with focal transphyseal ABC involvement (4/4, 100%) demonstrated focal bone bridge after treatment. No patient had diffuse physeal growth arrest; only patients with intraphyseal or transphyseal ABC involvement had focal physeal growth arrest.

CONCLUSIONS

In this series, patients undergoing percutaneous doxycycline treatment of juxtaphyseal ABCs demonstrated ABC healing and a recurrence rate of 6% at >18 months. Patients without physeal ABC involvement demonstrated no evidence of physeal growth arrest.

Imaging of presacral masses--a multidisciplinary approach

Our objective is to describe an approach for retrorectal/presacral mass evaluation on imaging with attention to imaging features, allowing for refinement of the differential diagnosis of these masses. Elaborate on clinically relevant features that may affect biopsy or surgical approach, of which the radiologist should be aware. A review of current literature regarding the diagnosis and treatment of retrorectal/presacral masses was performed with attention to specific findings, which may lend refinement to the differential diagnosis of these masses. Cases were obtained by searching through a radiology database at a single institution after Institutional Review Board approval. Recent advances in imaging and treatment methods have led to the increased role of radiology in both imaging and tissue diagnosis of retrorectal masses. Surgical philosophies surrounding the treatment of these masses have not significantly changed in recent years, but there are a few key factors of which the radiologist must be aware. The radiologist can offer refinement of the differential diagnosis of retrorectal masses and can elaborate on salient findings which could alter the need for neoadjuvant chemoradiation therapy, pre-surgical tissue diagnosis and surgical approach. This article presents an imaging approach to retrorectal/presacral masses with emphasis on findings which can dictate the ultimate need for neoadjuvant therapy and pre-surgical tissue diagnosis and alter the preferred surgical approach. This article consolidates key findings, so radiologists can become more clinically relevant in the evaluation of these masses.

Current Strategies for the Treatment of Aneurysmal Bone Cysts

Aneurysmal bone cysts are benign bone tumors that usually present in childhood and early adulthood. They usually manifest as expansile osteolytic lesions with a varying potential to be locally aggressive. Since their first description in 1942, a variety of treatment methods has been proposed. Traditionally, these tumors were treated with open surgery. Either intralesional surgical procedures or en bloc excisions have been described. Furthermore, a variety of chemical or physical adjuvants has been utilized in order to reduce the risk for local recurrence after excision. Currently, there is a shift to more minimally invasive procedures in order to avoid the complications of open surgical excision. Good results have been reported during percutaneous surgery, or the use of embolization. Recently, sclerotherapy has emerged as a promising treatment, showing effective consolidation of the lesions and functional results that appear to be superior to the ones of open surgery. Lastly, non-invasive treatment, such as pharmaceutical intervention with denosumab or bisphosphonates has been reported to be effective in the management of the disease. Radiotherapy has also been shown to confer good local control, either alone or in conjunction to other treatment modalities, but is associated with serious adverse effects. Here, we review the current literature on the methods of treatment of aneurysmal bone cysts. The indication for each type of treatment along reported outcome of the intervention, as well as potential complications are systematically presented. Our review aims to increase awareness of the different treatment modalities and facilitate decision-making regarding each individual patient.

Paediatric musculoskeletal interventional radiology

Interventional radiology technique is now well established and widely used in the adult population. Through minimally invasive procedures, it increasingly replaces surgical interventions that involve higher percentages of invasiveness and, consequently, of morbidity and mortality. For these advantageous reasons, interventional radiology in recent years has spread to the paediatric age as well. The aim of this study was to review the literature on the development, use and perspectives of these procedures in the paediatric musculoskeletal field. Several topics are covered: osteomuscle neoplastic malignant and benign pathologies treated with invasive diagnostic and/or therapeutic procedures such as radiofrequency ablation in the osteoid osteoma; invasive and non-invasive procedures in vascular malformations; treatment of aneurysmal bone cysts; and role of interventional radiology in paediatric inflammatory and rheumatic inflammations. The positive results that have been generated with interventional radiology procedures in the paediatric field highly encourage both the development of new ad hoc materials, obviously adapted to young patients, as well as the improvement of such techniques, in consideration of the fact that childrens' pathologies do not always correspond to those of adults. In conclusion, as these interventional procedures have proven to be less invasive, with lower morbidity and mortality rates as well, they are becoming a viable and valid alternative to surgery in the paediatric population.

Phytantriol based liquid crystal provide sustained release of anticancer drug as a novel embolic agent

Phytantriol has received increasing amount of attention in drug delivery system, however, the ability of the phytantriol based liquid crystal as a novel embolic agent to provide a sustained release delivery system is yet to be comprehensively demonstrated. The purpose of this study was to prepare a phytantriol-based cubic phase precursor solution loaded with anticancer drug hydroxycamptothecine (HCPT) and evaluate its embolization properties, in vitro drug release and cytotoxicity. Phase behavior of the phytantriol-solvent-water system was investigated by visual inspection and polarized light microscopy, and no phase transition was observed in the presence of HCPT within the studied dose range. Water uptake by the phytantriol matrices was determined gravimetrically, suggesting that the swelling complied with the second order kinetics. In vitro evaluation of embolic efficacy indicated that the isotropic solution displayed a satisfactory embolization effect. In vitro drug release results showed a sustained-release up to 30 days and the release behavior was affected by the initial composition and drug loading. Moreover, the in vitro cytotoxicity and anticancer activity were evaluated by MTT assay. No appreciable mortality was observed for NIH 3T3 cells after 48 h exposure to blank formulations, and the anticancer activity of HCPT-loaded formulations to HepG2 and SMMC7721 cells was strongly dependent on the drug loading and treatment time. Taken together, these results indicate that phytantriol-based cubic phase embolic gelling solution is a promising potential carrier for HCPT delivery to achieve a sustained drug release by vascular embolization, and this technology may be potential for clinical applications.

Percutaneous sclerotherapy with absolute alcohol to treat aneurysmal bone cyst of the frontal bone

Aneurysmal bone cysts (ABCs) rarely occur in the cranial bone. Surgical resection can lead to bone defects, deformities, functional abnormalities, and so on. This article describes a frontal ABC in a 73-year-old man who has a rapidly increasing swelling in the frontal bone preceded by an accidental trauma. In this case, we use percutaneous sclerotherapy with absolute alcohol under the guidance of fluoroscopy to treat the ABC instead of traditional surgical resection. When analyzed the follow-up imaging, bone reconstruction happened after using absolute alcohol. It is a feasible alternative treatment for ABC arising from the cranial bone.

Bone cysts: unicameral and aneurysmal bone cyst

Simple and aneurysmal bone cysts are benign lytic bone lesions, usually encountered in children and adolescents. Simple bone cyst is a cystic, fluid-filled lesion, which may be unicameral (UBC) or partially separated. UBC can involve all bones, but usually the long bone metaphysis and otherwise primarily the proximal humerus and proximal femur. The classic aneurysmal bone cyst (ABC) is an expansive and hemorrhagic tumor, usually showing characteristic translocation. About 30% of ABCs are secondary, without translocation; they occur in reaction to another, usually benign, bone lesion. ABCs are metaphyseal, excentric, bulging, fluid-filled and multicameral, and may develop in all bones of the skeleton. On MRI, the fluid level is evocative. It is mandatory to distinguish ABC from UBC, as prognosis and treatment are different. UBCs resolve spontaneously between adolescence and adulthood; the main concern is the risk of pathologic fracture. Treatment in non-threatening forms consists in intracystic injection of methylprednisolone. When there is a risk of fracture, especially of the femoral neck, surgery with curettage, filling with bone substitute or graft and osteosynthesis may be required. ABCs are potentially more aggressive, with a risk of bone destruction. Diagnosis must systematically be confirmed by biopsy, identifying soft-tissue parts, as telangiectatic sarcoma can mimic ABC. Intra-lesional sclerotherapy with alcohol is an effective treatment. In spinal ABC and in aggressive lesions with a risk of fracture, surgical treatment should be preferred, possibly after preoperative embolization. The risk of malignant transformation is very low, except in case of radiation therapy.

Treatment of a spinal aneurysmal bone cyst using combined image-guided cryoablation and cementoplasty

The authors describe the case of a 6.6-cm symptomatic spinal aneurysmal bone cyst (ABC) in a 17-year-old athlete treated percutaneously. Surgical treatment was not considered as the first option owing to its invasiveness and associated morbidity. CT-guided cryoablation of the expansile part of the ABC was performed for tumour shrinkage and nerve decompression. Thermal insulation, temperature monitoring and functional control/electrostimulation of the neural structures at risk were applied. Finally, the bony defect was cemented. No complications occurred during the procedure. Complete resolution of the ABC on imaging and clinical improvement were achieved. Percutaneous cryoablation should be considered as an alternative treatment option, especially when tumour size reduction is desired.

Background acetabular aneurysmal bone cyst in a 7 year-old: Presentation of a case

The bone cyst is a rare benign tumor that usually develops in childhood. There are several treatment options, however when it is located within the pelvis treatment is complex. A 7 year-old patient who presented with 3 months of right hip pain and limping. The initial radiograph showed a discrete periostic reaction and acetabulum effacement. The MRI and CT scans suggested the diagnosis of aneurysmal bone cyst and was confirmed by open biopsy. Two serial embolizations were performed with good results, the patient was asymptomatic one year after.

Functional outcomes and quality of life following surgical treatment of aneurysmal bone cysts of the pelvis in children

BACKGROUND

Aneurysmal bone cysts (ABCs) are a benign aggressive tumor that occurs rarely in the pelvis in the pediatric population. Pelvic ABCs may involve the triradiate cartilage and/or the acetabulum, which increases the technical difficulty of surgical treatment and has potential implications on the growth and development of the hip joint. This study examines the clinical presentation, rate of surgical complications, and recurrence rate, as well as, long-term clinical and functional outcomes of children with pelvic ABCs treated at a single institution by a single treatment modality.

METHODS

Between 1988 and 2008, 142 children with histologically confirmed ABCs were treated at our institution. Seventeen (12 %) tumors were located in the pelvis. A total of 13 pelvic ABCs (5 ilium-periacetabular, 4 pubic, 3 ilium-iliac wing, and 1 ischium) were included in this study. There were eight male and five female patients with a mean age of 12.9 years (range 4.1-17.5 years) at the time of surgery. The Toronto Extremity Salvage Score (TESS), the Musculoskeletal Tumor Society 1993 (MSTS'93) score, and the Short Form Health Survey Sf-36 were obtained at a minimum 5-year follow-up in all patients (mean follow-up 11.5 years, range 5.5-19.8 years). The mean age at follow-up was 24.3 years (range 14.6-32.6 years).

RESULTS

All patients were treated surgically with intralesional curettage extended with a high-speed burr and bone grafting. Eight patients received adjunctive therapy with phenol. Five patients had preoperative selective arterial embolization. Of the 13 patients, 1 had a local recurrence diagnosed at 6 months after surgery. The only complication in the cohort was a superficial wound infection. At the latest follow-up, all patients were free of disease. The mean TESS score was 95 and the mean MSTS'93 score was 93 %. The mean self-rated general health score, according to the SF-36 was 87 % of total points possible.

CONCLUSIONS

Extended curettage and bone grafting of pelvic ABCs in the pediatric population can yield high clinical and functional scores at an average of 11 years follow-up with a low rate of complications and recurrence.

LEVEL OF EVIDENCE

IV, case series.

Sclerotherapy with polidocanol for treatment of aneurysmal bone cysts

BACKGROUND AND PURPOSE

Recent data suggest that percutaneous sclerotherapy is a safe alternative to surgery for treatment of aneurysmal bone cysts (ABCs). We present our experience of this method.

METHODS

We retrospectively analyzed data from 38 consecutive patients treated with repeated injections of polidocanol. Each injection consisted of 2-4 mg polidocanol per kg body weight. Radiological and clinical assessments were performed until healing.

RESULTS

All cycts except 1 healed after a median of 4 (1-11) injections. A lesion failed to heal in 1 patient, who was operated. 3 patients experienced minor local inflammatory reactions.

INTERPRETATION

Our results show that percutaneus sclerotherapy with polidocanol has high efficacy in the treatment of ABCs, with a low frequency of side effects. Our findings corroborate data presented in previous publications. We believe that the method will be especially valuable in ABCs of the pelvis and sacrum, where surgery is associated with considerable morbidity.

Percutaneous doxycycline treatment of aneurysmal bone cysts with low recurrence rate: a preliminary report

BACKGROUND

Aneurysmal bone cyst (ABC) has a recurrence rate of between 12% and 71% without en bloc resection or amputation. There is no percutaneous ABC treatment drug regimen demonstrating consistent evidence of bone healing with recurrence of < 12%. Doxycycline has properties that may make it appropriate for percutaneous treatment.

QUESTIONS/PURPOSES

We therefore asked: (1) Is there reduction in ABC lytic cyst volume with injectable doxycycline? (2) Is it associated with thickening of involved bony cortex? (3) Is the recurrence rate after percutaneous treatment < 12%?

METHODS

We retrospectively reviewed 20 patients who underwent percutaneous treatment of ABCs with doxycycline from 2006 to 2010. The mean age was 10 years (range, 3-18 years). There were 21 treatment locations: humerus (six), spine (five), clavicle (two), fibula (one), femur (two), ulna (two), tibia (two), and scapula (one). Twenty patients completed treatment involving 118 treatment sessions (two to 14 sessions per patient). Treatment response was evaluated radiographically by measuring the lytic component and thickness of involved cortex. Recurrence was indicated by new areas of lytic destruction after completion of treatment. The minimum followup was 24 months (mean, 38 months).

RESULTS

Twenty of 20 patients demonstrated reduction in lytic destruction and bony healing. All patients demonstrated cortical thickening. One patient demonstrated recurrent minimal lytic destruction after 20 months of observation.

CONCLUSIONS

In this series, patients undergoing percutaneous doxycycline treatment of ABCs demonstrated a healing response and a recurrence rate of 5% at more than 24 months.

Aneurysmal bone cyst of the mobile spine: the therapeutic role of embolization

PURPOSE

Our aim is to define the role of embolization in the treatment of aneurysmal bone cyst of the spine in order to include this option in the decision making process.

METHODS

From April 2004 to November 2009, seven patients with primary aneurysmal bone cyst of the mobile spine treated by embolization have been prospectively followed-up. All clinical presentations and imagings were recorded. There are many options of embolic agent and techniques used, but all aim to devascularize the tumor. The therapeutic protocol includes: embolization repeated every 8 weeks until the appearance of radiographic signs of healing. Complications, rate of healing and clinical outcome were analyzed.

RESULTS

The number of embolizations varied from one to a maximum of seven without related intra- or post-operative complications. One patient, after four selective arterial embolizations, underwent direct percutaneous injection of embolic agents into the cyst. A clinical and radiographical response was achieved in all patients who were found alive and completely free of disease at mean follow-up of 46 months after last treatment and nobody crossed to surgical option.

CONCLUSION

Embolization seems to be the first option for spinal aneurysmal bone cyst treatment because of the best cost-to-benefit ratio. It is indicated in intact aneurysmal bone cyst, when diagnosis is certain, when technically feasible and safe and when no pathologic fracture or neurologic involvements are found. If embolization fails, other options for treatment would still be available.

Primary aneurysmal bone cysts in children: percutaneous sclerotherapy with absolute alcohol and proposal of a vascular classification

BACKGROUND

Percutaneous sclerotherapy is an effective treatment for aneurysmal bone cysts (ABCs).

OBJECTIVE

The purpose of this study was to demonstrate the safety and efficacy of sclerotherapy with absolute alcohol and to propose a vascular classification of ABCs based on a retrospective review.

MATERIALS AND METHODS

This was a review of children treated with absolute alcohol sclerotherapy for ABC at a single institution from January 1995 until November 2009. Treatment response was evaluated radiographically and clinically. Cyst fluid was classified as clear, partially bloody, or bloody. Presence of any venous drainage of the cyst was assessed by injection of contrast medium into the cyst cavity.

RESULTS

Twenty-nine children with ages ranging from 2 to 16 years were included. Treatment response was good in 17 (59%), partial in 9 (31%), and poor in 3 (10%) children. Venous drainage was absent in six out of seven clear-fluid cysts, which we classified as lymphatic. Drainage was present in all seven bloody-fluid cysts, which we classified as venous. In seven partially bloody-fluid cysts, venous drainage was seen in three.

CONCLUSION

Sclerotherapy with absolute alcohol is a safe and effective treatment of ABC. We propose classifying ABC as lymphatic or venous and suggest considering ABC intraosseous slow-flow vascular malformations.

Aneurysmal bone cyst

Aneurysmal bone cysts are rare skeletal tumors that most commonly occur in the first two decades of life. They primarily develop about the knee but may arise in any portion of the axial or appendicular skeleton. Pathogenesis of these tumors remains controversial and may be vascular, traumatic, or genetic. Radiographic features include a dilated, radiolucent lesion typically located within the metaphyseal portion of the bone, with fluid-fluid levels visible on MRI. Histologic features include blood-filled lakes interposed between fibrous stromata. Differential diagnosis includes conditions such as telangiectatic osteosarcoma and giant cell tumor. The mainstay of treatment is curettage and bone graft, with or without adjuvant treatment. Other management options include cryotherapy, sclerotherapy, radionuclide ablation, and en bloc resection. The recurrence rate is low after appropriate treatment; however, more than one procedure may be required to completely eradicate the lesion.

Factors associated with recurrence of primary aneurysmal bone cysts: is argon beam coagulation an effective adjuvant treatment?

BACKGROUND

Our goal was to assess the effectiveness and safety of argon beam coagulation as an adjuvant treatment for primary aneurysmal bone cysts, to reevaluate the adjuvant effectiveness of the use of a high-speed burr alone, and, secondarily, to identify predictors of aneurysmal bone cyst recurrence.

METHODS

We retrospectively reviewed the records of ninety-six patients with primary aneurysmal bone cysts who were managed at our institution from January 1, 1983, to December 31, 2008. Forty patients were managed with curettage, a high-speed burr, and argon beam coagulation; thirty-four were managed with curettage and a high-speed burr without argon beam coagulation; and the remaining twenty-two were managed with curettage with argon beam coagulation alone, curettage with no adjuvant treatment, or resection of the entire lesion. Demographic, clinical, and radiographic data were viewed comparatively for possible predictors of recurrence. Kaplan-Meier survival analysis with a log-rank test was performed to measure association and effectiveness.

RESULTS

The median age at the time of diagnosis was fifteen years (range, one to sixty-two years). The median duration of follow-up was 29.5 months (range, zero to 300 months). The overall rate of recurrence of aneurysmal bone cyst after surgical treatment was 11.5%. The rate of recurrence was 20.6% after curettage and high-speed-burr treatment alone and 7.5% after curettage and high-speed-burr treatment plus argon beam coagulation. The five-year Kaplan-Meier survival estimate was 92% for patients managed with curettage and adjuvant treatment with a high-speed burr and argon beam coagulation, compared with 73% for patients managed with curettage and a high-speed burr only (p = 0.060).

CONCLUSIONS

Surgical treatment of aneurysmal bone cyst with curettage and adjuvant argon beam coagulation is effective. Postoperative fracture appears to be a common complication of this treatment and needs to be studied further. Treatment with curettage and high-speed burr alone may not reduce recurrence.

Advance in the treatment of aneurysmal bone cyst of the sacrum

OBJECTIVE

The objective of this study was the review of 11 patients with two different treatment methods used historically for aneurysmal bone cyst in the sacrum. The outcome of both procedures is reported. In addition, the treatment technique of CT-guided percutaneous injections of demineralized bone matrix mixed with bone marrow concentrate is described.

MATERIALS AND METHODS

From 1997 to 2008, 11 patients with sacral aneurysmal bone cyst were treated at the Rizzoli Institute, Bologna, Italy. The first seven patients had surgical curettage without bone grafting, chemical adjuvants, or arterial embolization. The last four patients had arterial embolization. The last patient did not respond to arterial embolization and was treated by CT-guided injection of demineralized bone matrix mixed with bone marrow concentrate.

RESULTS

Curettage was successful in five out of seven patients. Two patients suffered complications, and two cases had recurrence. Arterial embolization was successful in three of four patients. The patient treated with injection had a good clinical and radiographic result.

CONCLUSION

Both surgical and arterial embolization are effective for aneurysmal bone cyst in the sacrum. However, these treatments may lead to complications and recurrence. The use of CT-guided injections of demineralized bone matrix mixed with bone marrow concentrate may be a safe and effective alternative for treatment of these destructive and problematic lesions.

Selective arterial embolisation for bone tumours: experience of 454 cases

PURPOSE

The authors present the experience of a single institution with selective arterial embolisation for primary and metastatic bone tumours.

MATERIALS AND METHODS

A total of 365 patients were treated with 454 embolisation procedures from December 2002 to April 2010. Embolisation was the primary treatment for benign bone tumours, adjuvant treatment to surgery for benign and malignant bone tumours and palliative treatment for bone sarcomas and metastases. Indications for repeat embolisation included pain or imaging evidence of progressive disease: 105 patients had repeat embolisation at the same location at an interval of 1-3 months; 260 patients had one embolisation, 78 had two and 29 had three or more. In all patients, N-2-butyl cyanoacrylate (NBCA) in 33% lipiodol was the embolic agent used.

RESULTS

A total of 419 of the 454 embolisations (93%) were technically successful. In 35 cases, embolisation was not feasible because of poor lesion vascularisation (21 patients with bone metastases and two with aneurysmal bone cysts), origin of the Adamkiewicz artery in the embolisation field (four patients with bone metastases and one with aneurysmal bone cyst), atheromatosis and arteriosclerosis (five patients with bone metastases) and anatomical and technical problems such as small-calibre vessels, many branches and acute vessel angles (two patients with bone metastases). A clinical response was achieved in 406 of the 419 procedures (97%), and no response in 13 procedures in patients with pelvis and sacrum tumours. Complications included postembolisation syndrome in 81 patients (22%), transient paraesthesias in 41 (11%), skin breakdown and subcutaneous necrosis at the shoulder and pelvis in five (1.4%) and paresis of the sciatic nerve in one (0.3%).

CONCLUSIONS

We recommend embolisation as primary or palliative treatment or an adjunct to surgery for tumours of variable histology. Strict adherence to the principles of transcatheter embolisation is important. Arteries feeding the tumour and collaterals must be evaluated carefully and catheterised superselectively to protect the normal tissues. NBCA is considered the most appropriate embolic agent for small-vessel occlusion without major complications.

Is sclerotherapy better than intralesional excision for treating aneurysmal bone cysts?

BACKGROUND

Minimally invasive approaches such as sclerotherapy have been introduced to treat aneurysmal bone cysts. Sclerotherapy has been associated with reasonable healing rates during the past two decades. However, it is unclear whether sclerotherapy compares with the more traditional extended curettage and bone grafting.

QUESTIONS/PURPOSES

We therefore compared the healing rates and functional scores in patients having percutaneous repetitive sclerotherapy using polidocanol (Group 1) with those with intralesional excision (extended curettage with a high-speed burr) and bone grafting (Group 2) for treatment of aneurysmal bone cyst.

PATIENTS AND METHODS

We randomly divided 94 patients into two treatment groups. We assessed healing rates (primary outcome measure), pain relief, time to healing and recurrence, hospital stay, and the Enneking functional score. Forty-five patients from Group 1 and 46 from Group 2 were available for study. The minimum followup was 3.2 years (mean, 4.4 years; range, 3.2-6.1 years).

RESULTS

At last followup, 93.3% in Group 1 and 84.8% in Group 2 had achieved healing. Complications in Group 1 were minor and resolved. In Group 2, three patients had deep infections and five had superficial infections, and two had growth disturbances. Although the healing rates were similar, we found higher rates of clinically important complications, worse functional outcomes, and higher hospital burden associated with intralesional excision.

CONCLUSIONS

Repetitive sclerotherapy using polidocanol is a minimally invasive, safer method of treatment for aneurysmal bone cysts compared with intralesional excision and bone grafting. In this preliminary study, we found similar recurrence rates for the two treatment methods, however, this will require confirmation in larger studies.

LEVEL OF EVIDENCE

Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Combined Percutaneous and Endovascular Treatment of Symptomatic Aneurysmal Bone Cyst of the Spine: Clinical Six Months. Follow-up of Six Cases

We describe the usefulness of endovascular and direct percutaneous treatment as a therapy option for aneurysmal bone cysts (ABCs) of the spine. From January 2007 to December 2008, we treated six consecutive patients with symptomatic ABCs resistant to continuous medical management or with acute clinical onset of paraparesis at cervical, thoracic and lumbar spine level. Two patients were treated after emergency laminectomy. All patients were studied with an MRI protocol and multidetector CT with MPR reconstructions followed by angiographic control before treatment. The procedure was performed under general anaesthesia for all patients. Under CT or fluoroscopy guidance, percutaneous treatment was performed either by direct injection of Glubran(®) diluted at 30% with Lipiodol(®) only, or combined with endovascular treatment by Onyx® injection. Clinical and X-ray follow-up was performed at three and six months. Combined endovascular and percutaneous treatment for ABCs was successful and led to an excellent outcome in five out of six patients with clinical improvement. There were no periprocedural or subsequent clinical complications and the glue resulted in successful selective permanent occlusion with intralesional penetration. Direct sclerotherapy resulted in immediate thrombosis of the malformation with no progression of symptoms. Complete healing was observed in five out of six aggressive lesions. No major complications were noted. At six month follow-up the symptoms had completely resolved and X-ray control showed a partial or total sclerotic reaction of the lesion with stable clinical results (no partial or clinical abnormalities). One patient had a recurrence of the ABC with spinal cord cervical clinical symptomatology. Combined endovascular and percutaneous treatment or direct percutaneous sclerotherapy with glue alone are important, safe, effective therapy options for symptomatic aneurysmal bone cyst. Results are stable and confirmed by clinical and X-ray follow-up six months after treatment.

Selective arterial embolization of 36 aneurysmal bone cysts of the skeleton with N-2-butyl cyanoacrylate

BACKGROUND

Aneurysmal bone cyst (ABC) is a lytic benign bone lesion representing about 1% of all primary bone tumors. The lesion causes pain and swelling, which are generally present for less than 3 months.

METHODS

From April 2003 to April 2008 36 patients affected by aneurysmal bone cysts were treated by selective arterial embolization with N-2-butyl cyanoacrylate. The study population comprised 20 male and 16 female patients with an age range of 3.3-60.8 years. Nine lesions were localized in the appendicular skeleton (1 in the upper and 8 in the lower limb), 4 in the thoracic cage (1 rib lesion and 3 scapular lesions), 17 in the pelvis and 6 in the spine (1 thoracic and 5 sacral localizations).

RESULTS

A total of 55 embolizations were performed: in 22 cases (61%) only one embolization was needed, whilst two embolizations were necessary in 9 cases (25%) and 3 in the remaining 5 patients (14%). The treatment was effective in 32 patients (94% ): follow-up was 0.9-5 years. In one patient, previously surgically treated, only the cyanoacrylate embolization turned out to be useful for healing the lesion. Another 7 patients underwent surgery during the study period. In the 55 procedures we performed we had 3 complications (5%): 2 cases of skin necrosis and 1 of transient paresis.

CONCLUSIONS

Arterial embolization with cyanoacrylate may be the treatment of choice for aneurysmal bone cysts. Embolization is a less invasive, lower cost, simpler procedure than surgery and is easily repeatable.

Aneurysmal bone cyst: the role of cryosurgery as local adjuvant treatment

BACKGROUND

Aneurysmal bone cysts (ABCs) are most often treated with intralesional surgery (curettage) and additional bone grafting. There is debate on whether or not to use adjuvant therapy to decrease the local recurrence rate. This study is done to assess the outcome of curettage and cryosurgery as a treatment of ABC.

METHODS

We analyzed 80 consecutive cases of ABC treated with curettage and cryosurgery. Patients were followed minimal 24 months after surgery (average 55 months, range 24-122 months) with physical examination and radiographs. Functional outcome was evaluated using the musculoskeletal tumor society score (MSTS).

RESULTS

The 80 patients were all treated with curettage and cryosurgery. Additional bone grafting was used in 73 patients, osteosynthesis in 12 and spondylodesis in 1 patient. Four local recurrences were found in this study, a recurrence rate of 5%. All local recurrences were treated successfully with curettage and cryosurgery again 7-33 months after the initial surgery. Postoperative one fracture, one wound infection, and three transient nerve palsy occurred. The average MSTS score was 29.2 at follow-up.

CONCLUSIONS

The use of cryosurgery as adjuvant therapy results in a lower local recurrence rate when compared to other publications for the treatment of ABC and excellent functional results.

Long-term follow-up of Ethibloc injection in aneurysmal bone cysts

The aim of this study is to assess the long-term results of Ethibloc injection in aneurysmal bone cysts (ABC). Thirty-three patients with ABC were treated with computed tomography-guided percutaneous injection of Ethibloc into the cyst cavity. Twenty-two patients had Ethibloc injection as primary treatment and 11 patients had presented to us with recurrence after previous procedures including steroid injection, bone marrow injection, curettage bone grafting and various other surgical procedures. The mean follow-up was 54 (22-90) months. Symptoms were relieved in all patients. Two patients were lost to follow-up. Eighteen (58%) of the 31 patients followed, had complete resolution of the lesion, 11 (35.5%) patients had partial healing (asymptomatic residual nonprogressive lytic areas). Two (6.5%) patients showed recurrence in the proximal humerus during the follow-up. They are under follow-up but asymptomatic and another two patients encountered more significant complications after the procedure. Ethibloc injection is a relatively simple, minimally invasive alternative procedure for the treatment of ABC, and makes open operation unnecessary by stopping the expansion of the cyst and inducing endosteal new bone formation. This technique may be used as the primary management of ABC's excluding spinal lesions as shown by our largest and longest follow-up study.