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

Modern treatment of unicameral and aneurysmatic bone cysts

The best treatment of unicameral bone cyst and aneurismatic bone cyst (ABC) is debated in the literature. For simple bone cysts, multiple treatments were proposed from observation only to open curettage. The historical treatment with intraosseous injection of methylprednisolone acetate into the bone cysts nowadays is reduced due to the morbidity of multiple injections and the risk of multiple pathologic fractures until the healing. Different types of treatments for ABC are reported, including surgery, percutaneous treatments, and medical treatments; however, there is currently no consensus on the best approach. The association of curettage, bone graft, and elastic stable intramedullary nail (ESIN) had a success rate of over 85%. Decompressing the cyst wall is more critical for increasing the healing rate than the type of graft used to fill the cavity. In ABC, sclerotherapy offers the advantages of lower invasiveness and morbidity, associated with better functional scores and faster return to full weight-bearing. Moreover, they can be used in challenging locations. Selective arterial embolization is a complex procedure and often requires association with other treatments. Further studies are needed to confirm the effectiveness of denosumab and its side effects on skeletally immature patients. Curettage with adjuvants and autogenous bone grafting still shows promising results and can be used in larger, aggressive defects or superficial lesions. For simple bone cysts, the combination of curettage, bone graft, and ESIN showed the best results. Sclerotherapy for ABC also shows promising results.

The Role of En Bloc Resection in the Modern Era for Primary Spine Tumors

STUDY DESIGN

A literature review.

OBJECTIVE

The aim of this review is to provide an overview of benign and malignant primary spine tumors and a balanced analysis of the benefits and limitations of (and alternatives to) surgical treatment with en bloc resection.

SUMMARY OF BACKGROUND DATA

Primary spine tumors are rare but have the potential to cause severe morbidity, either from the disease itself or as a result of treatment. The prognosis, goals, and treatment options vary significantly with the specific disease entity. Appropriate initial management is critical; inappropriate surgery before definitive treatment can lead to recurrence and may render the patient incurable, as salvage options are often inferior.

METHODS

We performed a comprehensive search of the PubMed database for articles relevant to primary spine neoplasms and en bloc spine surgery. Institutional review board approval was not needed.

RESULTS

Although Enneking-appropriate en bloc surgery can be highly morbid, it often provides the greatest chance for local control and/or patient survival. However, there is growing data to support modern radiotherapy as a feasible and less morbid approach to certain primary neoplasms that historically were considered radioresistant.

CONCLUSIONS

Choosing the optimal approach to primary spine tumors is complex. A comprehensive and up-to-date assessment of the evidence is required to guide patient care and to balance the often-competing goals of prolonging life and preserving quality of life.

Aneurysmal bone cyst: Is selective arterial embolization effective as curettage and bone grafting?

INTRODUCTION

Aneurysmal bone cyst (ABC) is a lytic benign bone lesion representing about 1% of all primary bone tumors. Method to treat ABC's have developed over time. The standard of care cure for ABC has been curettage with or without bone grafting of the defect but is burdened by recurrence rates of approximately 25%-31%. Based on the assumption that ABCs usually supplied by one or more pathological feeding arteries, selective arterial embolization has been described as an adjuvant preoperative procedure to reduce intra-operative hemorrhage, and as primary treatment for lesions in difficult surgical access. In the current study, we therefore asked whether (1) a single or a repeat selective arterial embolization (SAE) for treating ABCs would produce comparable healing rates compared with curettage and bone grafting; (2) evaluated the relationship of recurrence in relation to the site of the cyst, the age, and gender of the patients; and (3) the two techniques differ in term of long-term complication.

MATERIAL AND METHODS

We retrospectively reviewed 265 patients who underwent curettage and bone grafting or SAE performed at our institute from 1994 to 2018. The diagnosis of ABC was always established with percutaneous CT-guided biopsy or open biopsy. Patients were followed clinically with plain radiographs or CT scan at 3, 6, 9, and 12 months then annually in the absence of symptoms. Treatment success was determined evaluating pre- and postprocedural imaging according to Chang classification.

RESULTS

Two hundred and nineteen were treated with curettage and bone grafting (curettage group), and 46 with SAE Group. Of the 219 patients treated with Curettage and bone grafting (curettage group), 165 out of 219 (75.3%) experienced bone healing, while local recurrence was observed in 54 cases (24.7%) after 12 months on average (range: 3-120 months) from surgery. After the first SAE, bone ossification was seen in 27 (58.7%), without needing any further treatment. Eleven recurred patients were treated with SAE (four patients need two while seven need three SAE to heal), and eight patients with curettage and bone grafting. Thirty-eight out of 46 (82%) patients experienced bone ossification regardless the number of SAE. The overall rate of local recurrence for all patients was 26.7%. SAE group presented a lower complication rate (6%) where two patients experienced skin necrosis, and one limb-length discrepancies (2% of all cohort).

DISCUSSION

The use of SAE is an attractive option to treat ABC as it combines on one hand a lower complication rate than curettage and bone grafting, on the other it can be carried out in case of nonresectable ABCs, significantly reducing the size of viable ABC lesions, fostering bone remodeling and mineralization, and most importantly, significantly improving the patient's quality of life.

The New Ice Age of Musculoskeletal Intervention: Role of Percutaneous Cryoablation in Bone and Soft Tissue Tumors

In the rapidly evolving field of interventional oncology, minimally invasive methods, including CT-guided cryoablation, play an increasingly important role in tumor treatment, notably in bone and soft tissue cancers. Cryoablation works using compressed gas-filled probes to freeze tumor cells to temperatures below -20 °C, exploiting the Joule-Thompson effect. This cooling causes cell destruction by forming intracellular ice crystals and disrupting blood flow through endothelial cell damage, leading to local ischemia and devascularization. Coupling this with CT technology enables precise tumor targeting, preserving healthy surrounding tissues and decreasing postoperative complications. This review reports the most important literature on CT-guided cryoablation's application in musculoskeletal oncology, including sarcoma, bone metastases, and bone and soft tissue benign primary tumors, reporting on the success rate, recurrence rate, complications, and technical aspects to maximize success for cryoablation in the musculoskeletal system.

Primary Benign Neoplasms of the Spine

Benign tumours comprise the majority of primary vertebral tumours, and these are often found incidentally on imaging. Nonetheless, accurate diagnosis of these benign lesions is crucial, in order to avoid misdiagnosis as more ominous malignant lesions or infection. Furthermore, some of these tumours, despite their benign nature, can have localised effects on the spine including neural compromise, or can be locally aggressive, thus necessitating active management. Haemangiomas and osteomas (enostosis) are the commonest benign tumours encountered. Others include osteoid osteoma, osteoblastoma, fibrous dysplasia, osteochondroma, chondroblastoma, haemangioma, simple bone cysts, aneurysmal bone cysts, giant cell tumours, eosinophilic granuloma and notochordal rests. The majority of lesions are asymptomatic; however, locally aggressive lesions (such as aneurysmal bone cysts or giant cell tumours) can present with nonspecific symptoms, such as back pain, neurological deficits and spinal instability, which may be indistinguishable from more commonly encountered mechanical back pain or malignant lesions including metastases. Hence, imaging, including radiography, computed tomography (CT) and magnetic resonance imaging (MRI), plays a critical role in diagnosis. Generally, most incidental or asymptomatic regions are conservatively managed or may not require any follow-up, while symptomatic or locally aggressive lesions warrant active interventions, which include surgical resection or percutaneous treatment techniques. Due to advances in interventional radiology techniques in recent years, percutaneous minimally invasive techniques such as radiofrequency ablation, sclerotherapy and cryoablation have played an increasing role in the management of these tumours with favourable outcomes. The different types of primary benign vertebral tumours will be discussed in this article with an emphasis on pertinent imaging features.

The Efficacy of Denosumab in Treating Spinal Aneurysmal Bone Cyst: A Case Report

The optimal treatment for aneurysmal bone cysts (ABCs) of the spine remains controversial. No treatment guidelines exist for the use of denosumab in aneurysmal bone cysts. In this report, we describe the results from a representative case and compare our experience with those of previously published reports. A 38-year-old male was referred for pain in the lower back and left leg. Radiographs and a needle biopsy specimen revealed a lumbar aneurysmal bone cyst, which was treated with denosumab chemotherapy. The pain in the lower back and left leg gradually improved, and at 16 weeks, the symptoms had resolved. Once a satisfactory local effect was achieved, denosumab therapy was discontinued. However, the erosive lesion subsequently expanded. After re-initiation of treatment, there was no subsequent evidence of recurrence. Single-therapy denosumab is an option for aneurysmal bone cysts. However, recurrences have been documented after denosumab termination, and the timing for cessation of denosumab is controversial.

Quiste óseo aneurismático vertebral agresivo: presentación de un caso y revisión bibliográfica

Introducción: El quiste óseo aneurismático es una lesión seudotumoral lítica, expansiva, compuesta por espacios llenos de sangre separados por tabiques. Representa el 15% de los tumores primarios en la columna, y su presentación de comportamiento agresivo es aún más infrecuente. Se han descrito diferentes opciones terapéuticas en función de su estadio y tasa de recurrencia. Presentamos a un paciente con compromiso neurológico secundario a un quiste óseo aneurismático en la columna torácica, decomportamiento agresivo, que requirió resolución quirúrgica. Conclusión: Las opciones de tratamiento del quiste óseo aneurismático se deben adecuar a cada caso en particular, según sus características. Nivel de Evidencia: IV

Giant aneurysmal bone cyst of the scapula: A case report

Aneurysmal bone cyst (ABC) is a benign bone tumor affecting mainly children and young adults. It occurs in the metaphysis of the long bones. The scapula is a very rare location. Imaging may be highly suggestive of ABC in cases of an osteolytic, expansive, and hemorrhagic lesion with fluid-fluid levels and thin septa. The diagnosis must systematically be confirmed by performing a biopsy, in order to adopt the best therapeutic strategy. There are several therapeutic means, but wide resection remains the gold standard. The evolution is very variable and can go from spontaneous healing to recurrence with the destruction of the bone. We report a rare case of aneurysmal bone cyst of the scapula in a young patient.

Treatment of Aneurysmal Bone Cysts by Minimally Invasive Curettage and Allogenic Bone Impaction Grafting: Mid-to Long-term Results

OBJECTIVE

Recurrence is the main hinderance in treatment of aneurysmal bone cysts (ABCs). Therefore, several treatment modalities and adjuvant therapies have been proposed. In this study, we aim to evaluate the long-term effectiveness of percutaneous curettage and allogenic bone grafting as a new, minimally invasive modality in treating ABCs.

METHODS

We performed a retrospective review of the medical records of patients diagnosed with primary ABCs at a university hospital over a 10-year period (2000-2010). We selected all patients who were diagnosed with primary ABC in the extremities and pelvis, treated with the same surgical procedure, and were followed for at least 2 years postoperatively. All patients underwent the same procedure of percutaneous curettage and impaction of allogenic pulverized fine bone fragments (harvested from locally stored femoral heads) mixed with autologous bone marrow aspirate from the iliac bone. We reported patient's characteristics (age and gender), site and size of the lesion, presenting symptoms, Capanna classification, follow-up duration, and post-operative complications. Assessment of cyst healing was based on the appearance on radiographs according to the modified Neer classification.

RESULTS

Nineteen patients were included in this study; 10 patients were males and nine were females. The mean age was 9.6 years (range 3-15). The location of the lesions was as follows: femur (eight), tibia (four), pelvis (four), proximal humerus (one), distal radius (one), and calcaneus (one). The most common presenting symptom was pain in the involved area. Pathological fracture was the presenting feature in two patients. The mean follow-up duration was 6.4 years (range 2-18). The earliest radiological sign of incorporation of the allograft was seen at 3 months after surgery. All patients showed bone remodeling and radiographic resolution (classified as either A or B on the modified Neer classification) of their cystic lesions within 6 months. No local recurrence, infection, or pathological fractures occurred during the follow-up period.

CONCLUSION

Percutaneous curettage and impaction of allogenic bone graft mixed with autogenic bone marrow aspirate is an efficient, minimally invasive, reproducible, and affordable procedure for the treatment of primary ABCs.

Aneurysmal Bone Cyst (ABC) of the C2 Vertebra

An aneurysmal bone cyst (ABC) is a benign bone lesion commonly found in the younger age group. The principal aim of complete surgical excision to prevent recurrence in an ABC of the C2 vertebra presents a surgical challenge. We report a case of a 13-year-old with an ABC of the C2 vertebra and the strategies in its management surgically and pharmacologically.

Minimally invasive treatment of aneurysmal bone cysts: Systematic literature review

INTRODUCTION

The optimal treatment of aneurysmal bone cysts (ABC) remains controversial. Surgery has long been considered as the treatment that yields the best outcomes. Some authors now prefer using less invasive options as the primary treatment. The primary objective of this systematic literature review was to determine if treatments that are less invasive than surgery are also effective in curing the ABC. The secondary objective was to determine the respective role of each treatment in the therapeutic arsenal.

HYPOTHESIS

Less invasive treatments can replace surgery as the base treatment for ABC.

PATIENTS AND METHODS

A PubMed® search was carried out for this review. The inclusion criteria were ABC treatment without cyst removal, case series, clinical case reports, reviews, publication in French or English. Excluded were articles that described the results of surgical treatment only, cranial or maxillofacial cysts, secondary ABC, duplicates, no abstract available. Based on the first six items of the "MINOR criteria", we selected 42 studies. For each selected study, we analyzed the number of cases, clinical response to treatment, radiological healing, recurrence or failure rate, complications and side effects of the treatment.

RESULTS

This review found that less invasive treatments generate results that are at least as good as surgery, often with fewer complications. Thus, in certain cases, these treatments can be recommended as first-line therapy. This category includes selective arterial embolization, sclerotherapy (alcohol, polidocanol) and injection of demineralized bone matrix.

DISCUSSION

Selective arterial embolization yields good results. While this is a difficult, operator-dependent technique that is not suitable for all ABCs (no identifiable feeding vessel), we recommend it as the primary treatment for spinal ABCs. For ABCs in other locations, sclerotherapy can be used as the primary treatment. However, this treatment becomes inconvenient if the number of injections is too high. Radiation therapy is not a first-line treatment because of its side effects. Bisphosphonates and denosumab can be used when the other treatments are contraindicated.

Autologous mesenchymal stem cells in the treatment of spinal aneurysmal bone cyst

PURPOSE

We retrospectively analyzed a cohort of patients treated at our Centre with bone marrow concentrated (BMC) injection for aneurysmal bone cyst (ABC) of the spine, in order to propose this treatment as a valid alternative for the management of ABCs.

METHODS

Fourteen patients (6 male, 8 female) were treated between June 2014 to December 2019 with BMC injection for ABC of the spine. The mean age was 15.5 years. The mean follow up was 37.4 months (range 12-60 months). The dimension of the cyst and the degree of ossification were measured by Computed Tomography (CT) scans before the treatment and during follow-up visits.

RESULTS

Six patients received a single dose of BMC, five patients received two doses and in three patients three doses of BMC were administered. The mean ossification of the cyst (expressed in Hounsfield units) increased statistically from 43.48 ± 2.36 HU to 161.71 ± 23.48 HU during follow-up time and the ossification was associated to an improvement of the clinical outcomes. The mean ossification over time was significantly higher in patients treated with a single injection compared to patients treated with multiple injections. No significant difference in ossification was found between cervical and non-cervical localization of the cyst. Moreover, the initial size of the cyst was not statistically associated with the degree of ossification during follow-up CONCLUSIONS: Results of this paper reinforce our previous evidence on the use of BMC as a valid alternative for spinal ABC management when SAE treatment is contraindicated or ineffective.

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.

Endovascular approaches in pediatric interventional oncology

The demand for interventional oncological (IO) treatment of pediatric cancers is becoming increasingly common, at least at several tertiary care institutions. The data and techniques used in pediatric IO are largely extrapolated from experience in adult patients. The management of pediatric tumors differs from that in adults in several categories, such as, the curative intent of treatment, wide use of general anesthesia, aggressive pain management, potentially longer hospital stay, variation in chemotherapy dosing etc. Additionally, pediatric cancers are managed by protocols directed by national and international oncology groups such as the Children’s Oncology Group (COG). Consequently, the translation and adoption of these techniques is gradual, but there is a noticeable uptrend due to the growing need. This review will update the current endovascular IO treatments for common pediatric liver, renal, bone and soft tissue tumors.

Aneurysmal bone cyst of thoracic spine with neurological deficit and its recurrence treated with multimodal intervention - A case report

Background:

Aneurysmal bone cysts (ABCs) are rare, representing about 1% of primary bone tumors, and 15% of all primary spine/sacral tumors. Notably, when they are located in poorly accessible regions such as the spine and pelvis, their management may be challenging. Treatment options include selective arterial embolization (SAE), curettage, en bloc excision with reconstruction, and radiotherapy.

Case Description:

A 16-year-old male presented with 2 months of mid back pain, left-sided thoracic radiculopathy, and left lower limb weakness (MRC – 3/5). MR imaging revealed an expansile, lytic lesion involving the T9 vertebral body, and the left-sided posterior elements resulting in cord compression. He underwent SAE followed by intralesional excision, bone grafting, and a cage – instrumented fusion. ABC was diagnosed from the biopsy sample. Postoperatively, the pain was reduced, and he was neurologically intact. Five months later, he presented with a new lesion that was treated with repeated SAE and three doses of zoledronic acid. At the end of 2 years, the subsequent, MRI and CT studies documented new bone formation in the lytic areas, with healing of lesion; additionally, he clinically demonstrated sustained pain relief.

Conclusion:

Here, we emphasized the importance of surgery for patients with ABC who develop focal neurological deficits. Treatment options should include SAE with bisphosphonate therapy for lesions that recur without neurological involvement.

Strategy for the Practice of Spine Oncological Surgery During the Covid-19 Pandemic

STUDY DESIGN

Case series.

OBJECTIVE

For each of the most frequent clinical scenarios, the authors reached a consensus on how should be timing and indications be optimized to reduce risk while maintaining the expected outcomes under the Covid-19 pandemics.

SUMMARY OF BACKGROUND DATA

The organization of health care has been changed by the Covid-19 pandemic with a direct impact on Spine Oncology Surgery. Emergency surgery is still a priority, but in case of spinal tumors it should be better defined which conditions require emergency treatment.

METHODS

An expert panel with general spine surgeons, oncological spine surgeons, and radiation oncologists was formed to analyze the most frequent scenarios in spinal musculoskeletal oncology during Covid-19 pandemics.

RESULTS

Spine metastases can be found incidentally during follow-up or can clinically occur by increasing pain, pathologic fracture, and/or neurological symptoms. Primary spine tumors are much more rare and very rarely present with acute onset. The first step is to suspect this rare condition, to avoid to treat a primary tumor as it were a metastasis. Most complex surgery, like en bloc resection, associated with high morbidity and mortality rate for the treatment of low grade malignancy like chordoma or chondrosarcomas, if intensive care unit availability is reduced, can be best delayed some weeks, as not impacting on prognosis, due to the slow growth rate of these conditions. The currently accepted protocols for Ewing sarcoma (ES) and osteogenic sarcoma must be performed for local and systemic disease control. For ES, after the first courses of chemotherapy, radiotherapy can be selected instead of surgery, during Covid-19, to the end of the full course of chemotherapy. In immunocompromised patients, (treated by chemotherapy), it is necessary to avoid contact with affected or exposed people.

CONCLUSION

Even more than during normal times, a multidisciplinary approach is mandatory to share the decision to modify a treatment strategy.

LEVEL OF EVIDENCE

5.

Aneurysmal Bone Cysts of the Spine in Children: A Review of 18 Cases

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study was to evaluate the clinical presentation, treatments, outcome, complications, and recurrence rate in the surgical and nonsurgical management of spinal aneurysmal bone cyst (ABC) in a series of 18 pediatric patients.

METHODS

Between 1988 and 2014, we evaluated 18 pediatric patients diagnosed with ABC confirmed by pathology studies. We analyzed clinical and radiological features, non-surgical and surgical treatment, outcome, and complications.

RESULTS

The series included 12 male and 6 female patients with a mean age of 10 years and 4 months, with a mean follow-up of 5 years. Location of the ABC was lumbar in 8, cervical in 7, thoracic in 2, and sacral in 1 case. Axial pain was the most common symptom followed by radicular involvement. Surgery was performed in the presence of spine instability or neurological involvement (tumor resection) and in the remaining, nonsurgical treatment (percutaneous intralesional injection of methylprednisolone and calcitonin). Recurrence was observed in 4 patients requiring reintervention. There were no procedure-related complications.

CONCLUSION

In patients without neurological involvement or spinal instability, nonsurgical treatment is the treatment of choice. Total or subtotal removal combined with posterior instrumented spinal fusion is recommended in cases with a neurological deficit. Both procedures have shown good long-term results.

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.

Cervical Spine Aneurysmal Bone Cyst in a Pediatric Patient: Embolization Considerations and Potential Pitfalls

BACKGROUND

Aneurysmal bone cysts (ABCs) comprise 1%-2% of all bone tumors. ABCs involving the upper cervical spine in pediatric patients complicate intervention because of an immature skeleton and nearby neurovascular elements. Treatment often consists of surgical intervention with preoperative embolization to mitigate blood loss. During selective arterial embolization, it is important to be aware of extracranial-intracranial anastomoses from tumor feeding vessels. We describe a C2 vertebrae ABC that had multiple tumor arteries anastomosing with bilateral vertebral arteries.

CASE DESCRIPTION

A 3-year-old healthy girl presented with 1 month of progressive neck pain and palpable posterior neck mass. Imaging was most consistent with an ABC of the C2 vertebra. Preoperative embolization was planned. Angiography demonstrated tumor arterial supply anastomosing with the left and right vertebral artery stemming from the ascending and deep cervical artery branches. Tumor embolization was therefore carried out using coils and larger embolization particles to decrease ischemic stroke risk. Follow-up angiography showed successful tumor embolization with no vertebrobasilar complications. Surgical excision was uncomplicated and the patient's cervical spine has remained stable without fusion.

CONCLUSIONS

Preoperative embolization for ABC resection is common, but thorough angiography must be done to rule out dangerous extracranial-intracranial anastomoses. This case demonstrated 2 key anastomoses with the vertebral artery that if not recognized, could lead to disastrous consequences. Comprehensive angiographic evaluation is necessary because previous reports have described ischemic complications from embolization because of unrecognized vertebrobasilar anastomoses. If any angiographic evidence is seen, then larger particle size, coil embolization, or abandoning the case should be considered.

An aneurysmal bone cyst at T1 treated with bone grafts containing calcitonin and methylprednisolone

Aneurysmal bone cysts (ABCs) rarely trigger pathological fractures. Various surgical and nonsurgical treatments have been reported for this condition. Herein, we present the examination findings and treatment for a 15-year-old girl who initially presented with adolescent idiopathic scoliosis and mild back pain, but subsequently experienced severe back pain. Magnetic resonance imaging revealed an ABC at T1, with an associated pathological fracture. We successfully treated the patient using posterior fixation with instrumentation, curettage, and bone grafts combined with calcitonin and methylprednisolone (mPSL). At 3 years post-surgery, there was no ABC recurrence and only mild back pain persisted. To our knowledge, this is the first report of open surgery (curettage and fixation) with local intralesional administration of calcitonin and mPSL for an ABC-induced pathological spinal fracture. We believe that this treatment is an effective option for ABCs associated with a pathological spinal fracture.

Primary Aneurysmal Bone Cyst of the Thoracic Spine: A Pediatric Case Report

BACKGROUND

To date, only a few documented cases exist of complete or near-complete paraplegia of the lower extremities following collapse of a vertebral body secondary to an aneurysmal bone cyst. We describe the preceding symptoms associated with this catastrophic event along with surgical management and recovery.

CASE DESCRIPTION

A previously healthy, 13-year-old girl had experienced months of ongoing back pain with associated posture change. After collapsing at home in the bathroom, she was brought in by emergency medical services and presented to the neurosurgery service with an American Spinal Injury Association A spinal cord injury. Imaging revealed a collapsed T4 vertebral body including expanded and fluid-filled posterior elements and severe kyphotic spine angulation resulting in cord compression corresponding to her sensory and motor deficits. She underwent emergent surgery for spinal cord decompression with a T2-T4 laminectomy, transpedicular tumor resection, and T1-7 instrumented fusion. The patient tolerated the procedure well postoperatively. At 9 months after the event, she is ambulating independently without the use of crutches or a cane and has regained full strength for all muscle groups of her lower extremities.

CONCLUSIONS

The unique combination of back pain and posture change symptoms in an otherwise healthy pediatric patient should heighten clinical suspicion for a possible aneurysmal bone cyst of the spine when formulating a differential diagnosis. Additionally, despite the clinical severity at presentation, patients may still experience significant recovery following expeditious surgical intervention.

A case report of aneurysmal bone cyst of the thoracic spine treated by serial anterior and posterior fusion

RATIONALE

Aneurysmal bone cyst (ABC) is a benign, reactive, non-neoplastic, proliferative, highly vascular osseous lesion. Because of the rarity of aggressive ABC cases, diagnostic and treatment protocols remain controversial and problematic. Treatment of ABC includes surgery, radiotherapy, selective arterial embolization (SAE), and a combination of these modalities. Successful outcomes have been reported, but the technical requirements and complications of each modality are quite different. We report the clinical, radiological, and therapeutic aspects of ABC of the thoracic spine in an adolescent who was treated by circumferential fusion, and we review the published literature.

PATIENT CONCERNS

An 18-year-old boy was transferred to our hospital complaining of a 2-month history of neck pain.

DIAGNOSIS

ABC of the thoracic spine INTERVENTIONS:: Six days after SAE, T1 corpectomy was performed via an anterior approach. We performed the operation using the posterior approach 1 week after the anterior approach. Histopathological examination confirmed the diagnosis of ABC.

OUTCOMES

No neurologic deterioration occurred during the postoperative period. Follow-up X-rays 2 year postoperative showed good bony fusion and alignment.

LESSONS

Primary ABC of the spine is a benign lesion with a potential to be locally aggressive and a high rate of local recurrence. The optimal treatment of thoracic lesions is challenging due to their proximity to the spinal cord and nerve roots, and their frequent association with deformity. Surgical resection/curettage, SAE, and radiotherapy can be used alone or in combination. Complete exposure and resection is crucial to avoid the recurrence. Circumferential fusion and reconstruction of stability are also important for the treatment of thoracic ABC, especially in adolescent patient.

Spinal Aneurysmal Bone Cysts (ABCs): Optimal Management

Aim

To review the published literature on the treatment of aneurysmal bone cysts (ABCs).

Method

A systematic review of the English literature to April 2019 for all articles, with a minimum of three patients and 2-year follow-up, reporting on the treatment of spinal ABCs. The various treatment options were compared for the rates of recurrence, complications and mortality.

Results

Twenty-one articles and 272 patients (mean age 16.9 years, range 3–67) were included in this review. The overall recurrence rate for ABCs following all treatments is 12.8%. This is highest in those lesions described as being treated with isolated surgiflo injection into the lesion (100%), decompression/laminectomy (42.3%), partial excision/resection (35.7%) and curettage alone (25.0%). Radiotherapy alone or in conjunction with operative intervention offers excellent cure rates. Adjuncts to operative intervention, including cryotherapy or phenol reduce the recurrence rates, whereas embolization does not. The most common complications are persistent neurological deficits, spinal deformity, and continued pain. The overall mortality rates are low (1.5%). The reoperation rates are higher in surgical than non-surgical treatments and most are performed for progressive deformity.

Discussion

ABCs are highly radiosensitive. However, with the unknown longer-term risk of radiotherapy, surgical treatments, ideally with complete resection, and the use of adjunctive therapies such as cryotherapy or phenol, offer the best chance of cure. SAE is a useful adjunct to reduce intraoperative bleeding, but this study suggests that it only modestly improves recurrence rates. Newer techniques including bisphosphonate and doxycycline administration offer potential benefits, but their efficacy requires further investigation.

Denosumab for treating aneurysmal bone cysts in children

BACKGROUND

Aneurysmal bone cyst (ABC) is a benign tumour whose progression involves the RANK/RANKL signalling pathway. Surgery is the reference standard treatment but carries risks that vary with the site of the tumour. Denosumab is a human monoclonal IgG2 antibody that targets the RANK/RANKL pathway and may therefore hold promise for inhibiting ABC progression. The objective of this study was to evaluate denosumab use in paediatric patients (younger than 18 years) with ABC and to describe the clinical and radiological outcomes, as well as the side effect profile.

HYPOTHESIS

Denosumab is a viable option in children with ABC refractory to standard treatments.

MATERIAL AND METHODS

We retrospectively reviewed the medical files of paediatric patients given denosumab to treat ABC in any of 32 centres affiliated with the French Paediatric Cancer Society (Société Française du Cancer de l'Enfant, SFCE) and French Sarcoma Group (Groupe Sarcome Français, GSF-GETO). We identified 5 patients treated between March 2015 and June 2018. Median age was 8 years (range, 7-17 years). Pain was a symptom in all 5 patients and neurological deficits were present in 3 patients. Surgery was performed in 4 patients, either before (n=3) or after (n=1) denosumab therapy; the remaining patient had no surgery. Denosumab was given as monthly injections in a dosage of 70mg/m² for a median of 12 months (range, 4-23 months). The clinical outcomes and changes in computed tomography and/or magnetic resonance imaging findings were evaluated.

RESULTS

Abnormalities in calcium and phosphate levels secondary to the ABC occurred in 2 patients. At median of 24 months (range, 0-28 months) after denosumab initiation, all 5 patients were free of pain, and the neurological deficits in 3 patients had improved. Central remineralisation and cortical reconstitution were demonstrated consistently by the imaging studies.

DISCUSSION

Denosumab is a viable treatment option in selected paediatric patients with inoperable ABC. The immediate adverse effect profile is acceptable. A larger study with a longer follow-up would be welcome to further assess the contribution of denosumab to the treatment of ABC.

LEVEL OF EVIDENCE

IV.

Primary Bone Tumor of the Spine-An Evolving Field: What a General Spine Surgeon Should Know

STUDY DESIGN

A narrative review of the literature.

OBJECTIVE

This article reviews the general principles of treatment and investigation for primary bone tumors of the spine. Furthermore, it explores the emerging alternatives.

METHODS

A review was performed using Medline, Embase, and Cochrane databases.

RESULTS

Primary bone tumors of the spine are rare entities that general spine surgeons may encounter only a few times in their career. The treatment algorithm of these complex tumors is filled with nuances and is evolving constantly. For these reasons, patients should be referred to experienced tertiary or quaternary centers who can offer a comprehensive multidisciplinary approach. For most malignant spinal bone tumors, surgery remains the cornerstone of treatment. Respecting oncologic principles has been associated with improved survival and decreased local recurrence in multiple settings. However, even in experienced centers, these surgeries carry a significant risk of adverse events and possible long-term neurologic impairment. The associated morbidity of these procedures and the challenges of local recurrence have encouraged professionals caring for these patients to explore alternatives or adjuncts to surgical treatment.

CONCLUSIONS

Over the past few years, several advances have occurred in medical oncology, radiation oncology and interventional radiology, changing the treatment paradigm for some tumors. Other advances still need to be refined before being applied in a clinical setting.

Symptomatic aneurysmal bone cysts of the spine: clinical features, surgical outcomes, and prognostic factors

PURPOSE

The aim of the study was to report the long-term outcomes and analyze the potential prognostic factors that may contribute to symptomatic patients with aneurysmal bone cyst (ABC) of the spine undergoing surgical treatments.

METHODS

A retrospective analysis of consecutive patients with ABCs of the spine was performed. The clinical features were reviewed, and the disease-free survival (DFS) and overall survival (OS) rates were estimated using the Kaplan-Meier method. Factors with p values ≤ 0.05 were subjected to multivariate analysis by Cox proportional hazards model to identify the independent prognostic contributors. p values < 0.05 were considered statistically significant.

RESULTS

A total of 42 patients with ABCs of the spine were included in the study. All patients received surgical treatments. The mean follow-up period was 41.3 months (median 39.5, range 24-64). Local recurrence was detected in eight patients after surgery in our center, whereas death occurred in three patients. The estimated 5-year DFS and OS rate was 54.1% and 76.8%, respectively. The statistical analyses indicated that both en bloc resection and primary/secondary tumor status were independent prognostic factors for DFS.

CONCLUSIONS

Secondary ABC status may be associated with worse prognosis, and en bloc resection remains the treatment of choice for ABCs with neurologic deficits or spinal instability of the spine, which is correlated with better prognosis for local tumor control. These slides can be retrieved under Electronic Supplementary Material.

A large aneurysmal bone cyst of the rib

An aneurysmal bone cyst is a very rare benign tumor of the ribs. It mainly involves the long bones and vertebrae, and requires histopathological examination for definitive diagnosis. We present a case of large aneurysmal bone cyst of the left 6th rib in young adult male. The diagnosis of aneurysmal bone cyst should be kept in mind in young patients presenting with an expansile lytic lesion of the rib, because it has an excellent outcome after complete surgical resection.

Cervical Spine Osteoblastoma with an Aneurysmal Bone Cyst in a 2-Year-Old Child: A Case Report

Osteoblastomas and aneurysmal bone cysts are uncommon benign tumors of the spine. Their presentation can vary between diffuse pain, restriction of neck movements, torticollis, radiculopathy, and myelopathy. Complete excision is the best treatment to achieve a cure, but recurrence is not uncommon. A combination of the two conditions in the pediatric population is extremely rare. To the best of the authors' knowledge, only 2 cases of such a combination in the cervical spine have been reported in the literature. We report the case of a 2-year-old child having a right C4 lateral mass osteoblastoma with an aneurysmal bone cyst. The child underwent complete surgical excision of the lesion with fusion.

Complete resolution of a cervical spine aneurysmal bone cyst after single session of endovascular embolization: Case report

Treatment options for aneurysmal bone cysts include intralesional curettage, segmental excision, en bloc resection and endovascular embolization. The most commonly used treatment is intralesional curettage and selective arterial embolization is normally an adjunctive therapy, not a definitive treatment. We report a case of a C1 lateral mass aneurysmal bone cyst treated with a single session of endovascular embolization. Long-term follow up demonstrated complete resolution of the cyst. A study of aneurysmal bone cyst embolization was conducted and the key points for obtaining maximal devascularization of the cyst along with embolic material and technique are discussed.

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.

Imaging of Benign Tumors of the Osseous Spine

The purpose of this paper is to present an overview of the imaging features of the most prevalent benign bone tumors involving the spine. Benign tumors of the osseous spine account approximately for 1% of all primary skeletal tumors. Many lesions exhibit characteristic radiologic features. In addition to age and location of the lesion, radiographs are an essential step in the initial detection and characterization but are limited to complex anatomy and superposition. CT and MR imaging are often mandatory for further characterization, assessment of local extension and guiding biopsy.

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.

Aggressive development of an aneurysmal bone cyst of the proximal femur in a paediatric patient: a case report

We report development of an aneurysmal bone cyst (ABC) that was located in the proximal region of the femur in an 11-year-old girl. Over a period of 30 weeks, the ABC showed fulminant local progression, with destruction of the bone, which led to an abrupt loss of function of the left hip. The standard tumour treatment protocol was followed. We performed embolisation of the tumour followed by a biopsy, which confirmed the diagnosis of ABC. The outcome was negative with total destruction of the proximal third of the femur, despite repeating the embolisation. Because of the unfavourable local progression, a second biopsy was performed and we reconfirmed the initial diagnosis. The final decision regarding the therapeutic approach was total hip arthroplasty with femoral reconstruction with a prosthesis. Following this treatment, the patient’s outcome was favourable, with complete recovery of function and no local relapse.

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.

Treatment of aneurysmal bone cysts by percutaneous CT-guided injection of calcitonin and steroid

OBJECTIVES

To determine the efficacy and safety of percutaneous calcitonin and steroid injection in the treatment of aneurysmal bone cysts (ABCs).

MATERIALS AND METHODS

Our study was IRB-approved and HIPAA-compliant. We reviewed pre- and post-procedural imaging studies and medical records of all CT-guided percutaneous injections of ABCs with calcitonin and steroid performed at our institution between 2003 and 2015.

RESULTS

Treatment success based on imaging was categorized as substantial (51-100 %), partial (1-50 %), or none (0 %) by comparing radiographs of the lesion before and after treatment. Our study group comprised 9 patients (7 female, 2 male; mean age 19 ± 5 (range 12-25) years). ABCs were located in the pubis (n = 3), femur (n = 2), and humerus/scapula/ilium/sacrum (n = 1 for each). One patient did not have any clinical or imaging follow-up. For the other 8 patients, clinical and imaging follow-up ranged from 1 to 93 months (mean 16 ± 29 months). One patient had two injections, and 1 patient had three injections. Six out of eight patients (75 %) had complete symptomatic relief and 2 patients (25 %) had partial symptomatic relief after initial injection. Imaging follow-up revealed substantial imaging response in 4 out of 8 patients (50 %). There was a partial imaging response in 2 patients (25 %) and no imaging response in 2 out of 8 patients (25 %), and all 4 of these patients had local recurrence. There were no complications.

CONCLUSION

Percutaneous CT-guided injection of ABCs with calcitonin and steroid is a safe and effective treatment. Lack of imaging response may necessitate more aggressive treatment to minimize local recurrence.

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.

Benign Tumors of the Spine: Has New Chemotherapy and Interventional Radiology Changed the Treatment Paradigm?

STUDY DESIGN

Clinically based systematic review.

OBJECTIVE

To determine the role of (A) medical treatment and (B) interventional radiology as either adjuvant or stand-alone treatment in primary benign bone tumors of the spine.

METHODS

A multidisciplinary panel of spine surgeons, radiation oncologists, and medical oncologists elaborated specific focused questions regarding aneurysmal bone cyst, giant cell tumor, and osteoid osteoma. Denosumab, bisphosphonate, interferon, bone marrow aspirate, doxycycline, thermal ablation, and selective arterial embolization were identified as areas of interest for the article. A systematic review was performed through MEDLINE and EMBASE. Recommendations based on the literature review and clinical expertise were issued using the GRADE system.

RESULTS

The overall quality of the literature is very low with few multicenter prospective studies. For giant cell tumor, combination with Denosumab identified 14 pertinent articles with four multicenter prospective studies. Nine studies were found on bisphosphonates and six for selective arterial embolization. The search on aneurysmal bone cyst and selective arterial embolization revealed 12 articles. Combination with Denosumab, Doxycycline, and bone marrow aspirate identified four, two, and three relevant articles respectively. Eleven focused articles were selected on the role of thermal ablation in osteoid osteoma.

CONCLUSION

Alternative and adjuvant therapy for primary benign bone tumors have emerged. Their ability to complement or replace surgery is now being scrutinized and they may impact significantly the algorithm of treatment of these tumors. Most of the data are still emerging and further research is desirable. Close collaboration between the different specialists managing these pathologies is crucial.

LEVEL OF EVIDENCE

N/A.