Acute spinal cord compression in hereditary multiple exostoses

Identification of clinical and radiographic predictors of central nervous system injury in genetic skeletal disorders

Some studies report neurological lesions in patients with genetic skeletal disorders (GSDs). However, none of them describe the frequency of neurological lesions in a large sample of patients or investigate the associations between clinical and/or radiological central nervous system (CNS) injury and clinical, anthropometric and imaging parameters. The project was approved by the institution’s ethics committee (CAAE 49433215.5.0000.0022). In this cross-sectional observational analysis study, 272 patients aged four or more years with clinically and radiologically confirmed GSDs were prospectively included. Genetic testing confirmed the diagnosis in the FGFR3 chondrodysplasias group. All patients underwent blinded and independent clinical, anthropometric and neuroaxis imaging evaluations. Information on the presence of headache, neuropsychomotor development (NPMD), low back pain, joint deformity, ligament laxity and lower limb discrepancy was collected. Imaging abnormalities of the axial skeleton and CNS were investigated by whole spine digital radiography, craniocervical junction CT and brain and spine MRI. The diagnostic criteria for CNS injury were abnormal clinical and/or radiographic examination of the CNS. Brain injury included malacia, encephalopathies and malformation. Spinal cord injury included malacia, hydrosyringomyelia and spinal cord injury without radiographic abnormalities. CNS injury was diagnosed in more than 25% of GSD patients. Spinal cord injury was found in 21.7% of patients, and brain injury was found in 5.9%. The presence of low back pain, os odontoideum and abnormal NPMD remained independently associated with CNS injury in the multivariable analysis. Early identification of these abnormalities may have some role in preventing compressive CNS injury, which is a priority in GSD patients.

The Incidence of Vertebral Exostoses in Multiple Hereditary Exostoses and Recommendations for Spinal Screening

BACKGROUND

Multiple hereditary exostoses (MHE) lead to the development of pedunculated or sessile osteocartilaginous lesions. Vertebral involvement occurs in MHE and encroaching intracanal exostoses can result in devastating consequences. Magnetic resonance imaging (MRI) of the entire spine has been used to screen for vertebral exostoses to detect high-risk patients. The primary purpose of this investigation is to determine the incidence of vertebral and encroaching intracanal exostoses in patients with MHE. A secondary purpose is to determine if pelvis and rib exostoses serve as "harbinger" lesions of vertebral involvement in MHE.

METHODS

A retrospective chart review was performed on 39 patients (21 male and 18 female individuals) with MHE who underwent routine spinal screening with noncontrast entire spine MRI. The average age at screening was 12.3 years (range, 3 to 17 y). Screening was ordered consecutively on patients seen during the study period who were between ages 8 and 18 years or had complaints that could be related to encroaching intracanal exostoses.

RESULTS

The incidence of vertebral exostoses in this cohort of 39 patients with MHE was 28% (11 total). An encroaching intracanal exostosis was seen in 3 patients (2 cervical, 1 thoracic). Nonencroaching vertebral exostoses were discovered in 8 patients. Sufficient pelvis and rib imaging to determine the presence of pelvis and rib exostoses was available in 8 of those with vertebral exostoses and 19 of those with no vertebral exostoses on screening MRI. In this cohort, the sensitivity and specificity of the presence of both pelvis and rib exostoses for determining the presence of spinal involvement in MHE are 88% and 5%, respectively.

CONCLUSIONS

Based on the results of this cohort, vertebral exostoses are common in MHE, and screening MRI of the entire spine can be used to determine which patients need close observation. If a more selective screening protocol is utilized, an entire spine MRI could be obtained for patients who desire increased physical activity levels or for patients with both pelvis and rib exostoses. At a minimum, treating physicians should monitor patients with MHE closely for neurological symptoms and have a low threshold to obtain advanced spinal imaging.

LEVEL OF EVIDENCE

Level III-diagnostic.

Diagnosis, Management, and Treatment Options: A Cervical Spine Osteochondroma Meta-Analysis

Osteochondroma is described as a capped benign bony neoplasm that forms on the outer surface of bone. These tumors affect nearly 6 million people per year. Although osteochondromas most often involve the appendicular skeleton, many involve the spine, with many cases located in the cervical spine. When osteochondromas involve the spine, they can present with a variety of symptoms, including pain, radiculopathy, and myelopathy, which may necessitate surgical treatment. Spinal osteochondromas can be classified into 2 types: multiple osteochondromas in the context of patients with multiple hereditary exostosis (MHE) and solitary osteochondroma or solitary exostosis (SE). Previous reviews have captured only some of the available literature on cervical osteochondromas and have generally focused on either SE or those associated with MHE. The purpose of our review was to provide an extensive review of all previously reported cervical osteochondromas and to compare osteochondroma characteristics, clinical presentation, and outcomes in the context of MHE and SE.

Cervical osteochondroma: surgical planning

INTRODUCTION

Osteochondromas are benign bone tumors which occur as solitary lesions or as part of the syndrome multiple hereditary exostoses. While most osteochondromas occur in the appendicular skeleton, they can also occur in the spine. Most lesions are asymptomatic however some may encroach on the spinal cord or the nerve roots causing neurological symptoms. While most patients with osteochondromas undergo laminectomy without fusion, laminectomy with fusion is indicated in appropriately selected cases of spinal decompression.

CASE PRESENTATION

We present a case of a 32-year-old male with history of multiple hereditary exostoses who presented with symptoms of bilateral upper extremity numbness and complaints of gait imbalance and multiple falls. He reported rapid progression of his symptoms during the 10 days before presentation. Computed tomography of the cervical spine revealed a lobulated bony tumor along the inner margin of the cervical 4 lamina. He underwent cervical 3 and 4 laminectomies, partial cervical 2 and 5 laminectomies and cervical 3-5 mass screw placement. Pathology was consistent with osteochondroma. The patient's symptoms had markedly improved at follow-up.

CONCLUSION

According to our literature review, osteochondromas most commonly occur at cervical 2 and cervical 5. We present a case of an osteochondroma at a less common level, cervical 4. While most osteochondromas are addressed with laminectomy without arthrodesis, the decision of whether arthrodesis is necessary should be considered in all patients with osteochondroma as with any cervical decompression.

Spinal Screening MRI Trends in Patients with Multiple Hereditary Exostoses: National Survey

Background

Multiple hereditary exostoses (MHE) is a rare disease characterized by multiple osteochondromas. Osteochondromas growing into the spinal canal can produce devastating consequences, including permanent neurologic deficits and even death. Routine screening of the entire spinal canal with magnetic resonance imaging (MRI) is a controversial topic lacking a clear consensus or recommendation to guide decision-making. This study presents a case of an intracanal osteochondroma at C1 identified by routine screening and a survey describing current practices of MHE experts.

Methods

MHE experts were surveyed. Survey questions addressed multiple aspects of care, including the type of practice center, the volume of patients with MHE, and current screening practices.

Results

A total of 104 experts were contacted, with a total of 26 experts participating in the survey and 23 completing the entire survey. Seventy-two percent of respondents do not perform a routine MRI screen of the spine. For experts that routinely screen, screening is performed across a wide/variable age range (4-18 years).

Conclusion

Screening protocols for MHE patients to identify osteochondromas within the spinal canal has struggled to reach consensus due to the rarity of the disease. Recent literature provides conflicting advice for patients without neurological symptoms. Our study demonstrates that even experts who are leading the field demonstrate wide practice variability. Most respondents do not routinely perform screening spinal MRI. Due to the wide variability, a national guideline is needed to help guide physician and parental decision-making for patients with MHE. Our case illustrates the potential benefit of identifying an osteochondroma within the spinal canal at a location where further growth could have devastating neurological sequelae.

Late presentation of spinal cord compression in hereditary multiple exostosis: case reports and review of the literature

INTRODUCTION

Osteochondromas are usually found in the long bones of patients with hereditary multiple exostoses (HME). The spine is reported to be involved in over 50% of cases, but few of these patients are symptomatic as the result of an existing spinal exostosis.

METHODS

We reviewed the current literature in order to find the right approach to patients with HME-complicated spinal exostosis and describe three paediatric patients that were diagnosed late with spinal cord compression due to cervical exostosis.

RESULTS

Our three cases were all late presentations with neurology and unfortunately had minimal improvement of neurology after the lesion was surgically removed. There is general agreement that late presentation of spinal cord injury due to osteochondromas involving the cervical spine may cause severe and irreversible neurological sequelae. Our literature review revealed that there are no clear-cut guidelines to develop more comprehensive screening measures for these patients.

CONCLUSIONS

A high index of suspicion is the most important factor for correct diagnosis and appropriate management. Physicians who treat HME should bear in mind that thorough history taking and a neurological examination at follow up are essential for these patients. Clearer guidelines for the development of more comprehensive screening programmes are essential.

LEVEL OF EVIDENCE

IV.

Transpedicular Excision of a Thoracic Intraspinal Osteochondroma in a Patient with Hereditary Multiple Exostoses and Brown-Séquard Syndrome

BACKGROUND

Spinal osteochondroma is a rare but recognized cause of myelopathy. Brown-Séquard syndrome is a form of severe myelopathy characterized by a clinical picture of hemisection of the spinal cord. Brown-Séquard syndrome caused by osteochondroma is extremely rare, calling for individualized surgical procedures.

CASE DESCRIPTION

We report a 16-year-old girl with hereditary multiple exostoses and a rare case of thoracic osteochondroma causing partial Brown-Séquard syndrome. Customized surgical procedures were designed to avoid iatrogenic spinal cord injury. The patient underwent neural decompression and tumor excision through a transpedicular approach. The surgical procedure consisted of 4 consecutive steps: 1) laminectomy, 2) costotransversectomy and pediculectomy, 3) extracavitary removal of the mass, and 4) pedicular fixation with fusion. Total resection of the tumor was achieved macroscopically without intraoperative spinal cord injury. The postoperative recovery was uneventful, and the patient returned to a normal life without evidence of recurrence at 24-month follow-up.

CONCLUSIONS

For patients with hereditary multiple exostosis and new onset of neurologic symptoms, the possibility of a spinal osteochondroma should be considered. In the situation of an intraspinal exostosis protruding from the lateral side, customized surgical procedures with a transpedicular approach may be a valid way to minimize intraoperative neural injury and achieve a satisfactory outcome.

Management of nerve compression in multiple hereditary exostoses: a report of two cases and review of the literature

PURPOSE

Multiple hereditary exostoses (MHE) is a rare autosomal dominant condition that results in the growth of cartilage-capped prominences that often cause nerve compression and injury. Many patients suffer from continued and debilitating chronic pain which leads some to advocate avoiding surgical intervention in patients with multiple hereditary exostoses. We present a review of the literature as well as a case series at our institution in order to evaluate the role of surgery in multiple hereditary exostoses.

METHODS

We searched the literature for reports of patients with multiple hereditary exostoses undergoing surgery for nerve compression. We then reviewed the recent experience at our institution which revealed two patients with multiple hereditary exostoses.

RESULTS

Our literature search revealed that there have been several case series and retrospective analyses in the literature that assess the benefit of surgery in the case of nerve compression caused by exostoses. The majority of these reports are of solitary exostoses. Few reports expand on the role of surgery in patients with multiple hereditary exostoses suffering from nerve compressions secondary to bony overgrowth. A recent review of the experience at our institution revealed two patients with multiple hereditary exostoses who together underwent a total of four surgeries for treatment of peripheral nerve compression resulting in pain or weakness. Postoperative evaluation revealed improvement in pain and/or motor strength following each operation.

CONCLUSION

Based on our experience and literature review, we advocate that nerve compression in selected individuals with multiple hereditary exostoses that results in neurological injury should be considered for nerve decompression and resection of the offending exostosis.

Bilateral Scapulothoracic Osteochondromas in a Patient With Hereditary Multiple Exostosis: A Case Report and Review of the Literature

Hereditary multiple exostosis (HME) is an autosomal dominant disorder characterized by two or more benign growing, cartilage capped tumors of long bones called osteochondromas. If abnormal growth and clinical symptoms of osteochondromas newly appear in adults, malignant transformation of the usually benign growing tumors should be suspected and diagnostic testing should be initiated. Against the background of hypothesized higher malignant transformation of osteochondromas into chondrosarcoma in individuals with shoulder exostoses, we report a case of bilateral scapulothoracic osteochondromas in a patient suffering from HME. A 60-year-old female with HME complained of chest pain while being hospitalized for bilateral femoral fractures. A computed tomography scan of the chest was performed to rule out pulmonary embolism. However, bilateral osteochondromas in the scapulothoracic spaces were detected. Due to absence of radiographic evidences for malignant transformation in the patient, invasive diagnostic procedures such as biopsy and histological examination were recommended in order to exclude malignant transformation of both osteochondromas. Physicians should be aware that patients with HME who present with shoulder pain should be examined for osteochondromas in the scapulothoracic space. Due to possible sarcomatous transformation, regular follow-ups are necessary for adolescents and adults.

Cervical myelopathy due to a solitary osteochondroma: a case report

Introduction

Osteochondroma is the most common benign bone tumor. However, the incidence of osteochondroma in the spine is reported to be very rare.

Case description

This report presents the case of a 57-year-old man who suffered from osteochondroma of the cervical spine. He had bilateral lower extremity pain for 3 years, developing pain of right upper extremity and gait disturbance. Plain radiographic images and computed tomography scans showed bony lesion in right C6/7 foramen and C6 lamina. Magnetic resonance images of whole spine showed severe compression of spinal cord at the C6/7 and spinal canal stenosis at the L3/4 level. First, we performed a surgery of the cervical spine, and removed the tumor covered with the cartilaginous cap. The pathological diagnosis of the tumor was osteochodroma. After the surgery, the symptoms on his right upper extremity improved smoothly. Because the bilateral lower extremity pain remained, a L3/4 partial laminectomy was performed 1 month later, and the symptom improved. At 1 year after his primary operation, we could not find a recurrence of the tumor.

Conclusions

It is very important to perform a complete en bloc resection of the tumor (especially cartilaginous cap) to prevent the recurrence.

Multidetector computed tomography in the evaluation of hereditary multiple exostoses

Hereditary multiple exostoses (HME) is an autosomal dominant disorder characterized by the formation of multiple osteochondromas. Because of its superior soft tissue contrast and absence of ionizing radiation, magnetic resonance imaging is the first choice imaging technique for the evaluation of complex lesions and complications related to HME. However, multidetector computed tomography (MDCT) also can be of value in the evaluation of patients with HME, which is reviewed in this article. Topics outlined are low-dose MDCT technique, 3-dimensional visualization techniques, typical MDCT appearances, differential diagnostic considerations, and the usefulness of MDCT in the assessment of emergent and non-emergent complications related to HME, among which spinal cord compression, pneumothorax and hematothorax, pseudoaneurysms, fractures, growth disturbances, chondrosarcoma transformation, and muscular and peripheral nerve involvement.

Prolonged Subdural Infusion of Kynurenic Acid Is Associated with Dose-Dependent Myelin Damage in the Rat Spinal Cord

BACKGROUND

Kynurenic acid (KYNA) is the end stage metabolite of tryptophan produced mainly by astrocytes in the central nervous system (CNS). It has neuroprotective activities but can be elevated in the neuropsychiatric disorders. Toxic effects of KYNA in the CNS are unknown. The aim of this study was to assess the effect of the subdural KYNA infusion on the spinal cord in adult rats.

METHODS

A total of 42 healthy adult rats were randomly assigned into six groups and were infused for 7 days with PBS (control) or 0.0002 pmol/min, 0.01 nmol/min, 0.1 nmol/min, 1 nmol/min, and 10 nmol/min of KYNA per 7 days. The effect of KYNA on spinal cord was determined using histological and electron microscopy examination. Myelin oligodendrocyte glycoprotein (MOG) was measured in the blood serum to assess a degree of myelin damage.

RESULT

In all rats continuous long-lasting subdural KYNA infusion was associated with myelin damage and myelin loss that was increasingly widespread in a dose-depended fashion in peripheral, sub-pial areas. Damage to myelin sheaths was uniquely related to the separation of lamellae at the intraperiod line. The damaged myelin sheaths and areas with complete loss of myelin were associated with limited loss of scattered axons while vast majority of axons in affected areas were morphologically intact. The myelin loss-causing effect of KYNA occurred with no necrosis of oligodendrocytes, with locally severe astrogliosis and no cellular inflammatory response. Additionally, subdural KYNA infusion increased blood MOG concentration. Moreover, the rats infused with the highest doses of KYNA (1 and 10 nmol/min) demonstrated adverse neurological signs including weakness and quadriplegia.

CONCLUSIONS

We suggest, that subdural infusion of high dose of KYNA can be used as an experimental tool for the study of mechanisms of myelin damage and regeneration. On the other hand, the administration of low, physiologically relevant doses of KYNA may help to discover the role of KYNA in control of physiological myelination process.

Cervical myelopathy caused by disc herniation at the segment of existing osteochondroma in a patient with hereditary multiple exostoses

Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5-6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc.

Complete recovery of severe tetraparesis after excision of large C1-osteochondroma

Severe tetraparesis resulting from cervical cord compression due to osteochondroma of the Atlas is a rare condition, especially in young children. In this report, the author discusses the clinical presentation, and outcome of surgical excision of a large C1 osteochondroma presenting with severe myelopathic tetraparesis, in a 10-year-old girl. Computed tomography and magnetic resonance images revealed a large bony lump arising from the posterior arch of atlas, filling most of the spinal canal, and compressing the cervical spinal cord. Another histologically proven exostosis was incidentally found at the spinous process of T1. There was no history of exostosis in the family, and the patient improved dramatically after removal of the C1 osteochondroma.

Spinal stenosis frequent in children with multiple hereditary exostoses

PURPOSE

Children with multiple hereditary exostoses (MHE) have numerous osteochondromas, with the most prominent lesions typically over the appendicular skeleton. A recent report noted a high rate of intracanal lesions in this patient population and recommended preventative spinal screening with magnetic resonance imaging (MRI) or computed tomography (CT). We sought to evaluate the prevalence of spinal stenosis from intracanal osteochondromas at our pediatric orthopedic center in order to evaluate if routine screening is warranted.

METHODS

All pediatric patients treated for MHE were retrospectively identified. Records were reviewed to determine demographics, previous orthopedic surgery, and indication and results of axial spine imaging (CT or MRI). Imaging studies were reviewed to evaluate the presence of intracanal and compressive spinal lesions.

RESULTS

Between 1990 and 2011, axial imaging was performed in nine patients with MHE due to concerns of pain, weakness, and/or dizziness. These patients had moderate disease involvement, with a mean of 4.9 previous orthopedic surgeries to address skeletal osteochondromas. Two patients with MHE had cervical spinal stenosis secondary to intracanal osteochondromas. Both children successfully underwent spinal decompression. Thus, of our MHE population undergoing axial imaging, 22 % were noted to have intracanal lesions.

CONCLUSIONS

Our experience reveals a >20 % rate of compressive intracanal osteochondromas in MHE patients undergoing spinal imaging. These two patients represent 5 % of the MHE patients treated at our center. These lesions may be slow growing, and significant consequences can occur if not identified promptly. Thus, we confer that routine axial screening of the spinal canal may be warranted in these children.

[Cervical cord compression by hereditary multiple exostosis: case report and review of literature]

BACKGROUND

Hereditary multiple exostosis (HME) is an hereditary disease, characterized by the presence of multiple osteochondromas; 7% of patients with HME have a spinal disease. Through this observation, the authors discuss the diagnostic and therapeutic aspects of this rare lesion.

CASE REPORT

A 45-year-old woman, operated 10 years ago for an exostosis of the right fibula and left femur. She has since few years paresthesia of all four limbs with distal predominance, walking fatigability kind of spinal claudication. The MRI shows a voluminous osteoma at the second cervical vertebra compressing the spinal cord. The patient was operated with macroscopically complete resection of the exostosis and C2 laminectomy.

CONCLUSION

The cervical exostosis associated with HME is a rare disease. The clinical symptomatology is dominated by spinal cord compression and surgical treatment allows excellent clinical results.

Cervical myelopathy caused by atlas osteochondroma and pseudoarthrosis between the osteochondroma and lamina of the axis: case report

A 58-year-old man presented with a 6-month history of progressive cervical myelopathy. Magnetic resonance imaging and computed tomography of the cervical spine revealed a bone tumor arising from the posterior arch of the atlas and osteophytes at a pseudoarthrosis between the tumor and the lamina of the axis, resulting in marked spinal cord compression. The patient's symptoms resolved after en bloc resection of the tumor and removal of the osteophytes. The histological diagnosis was osteochondroma. The primary cause of myelopathy in the present case was osteochondroma arising from the posterior arch of the atlas, but the osteophyte formations appearing at the pseudoarthrosis between the atlas osteochondroma and the lamina of the axis might also have contributed to the symptoms, which appeared when the patient was in his late 50s.

Involvement of the spine in patients with multiple hereditary exostoses

BACKGROUND

Extension of a vertebral exostosis into the spinal canal is rare, but many isolated cases have been reported in the literature. Three existing patients with multiple hereditary exostoses at our institution had development of neurologic findings and were found to have exostoses in the spinal canal. These findings led us to perform magnetic resonance imaging or computed tomographic scans for the remaining patients with multiple hereditary exostoses at our institution.

METHODS

Forty-four patients at our institution (including twenty-six male patients and eighteen female patients) had multiple hereditary exostoses. Forty-three patients were evaluated with magnetic resonance imaging and one was evaluated with computed tomography to look for spinal column involvement.

RESULTS

Thirty (68%) of the forty-four patients had exostoses arising from the spinal column, and twelve (27%) had lesions encroaching into the spinal canal. Thirty-six of the forty-four patients also had plain radiographs, but only six had radiographs that accurately identified the lesions and another six had radiographs that mistakenly identified lesions that were not confirmed with magnetic resonance imaging or computed tomography. Patients with lesions inside the spinal canal were typically asymptomatic and neurologically normal, with radiographs that did not demonstrate the lesion. Compared with female patients, male patients were more likely to have spinal lesions and more likely to have lesions encroaching into the spinal canal (p = 0.014).

CONCLUSIONS

The risk that a patient with multiple hereditary exostoses has a lesion within the spinal canal is much higher than previously suspected (27%). Because the potential exists for serious neurologic injury to occur, we have begun to use magnetic resonance imaging to screen all patients who have multiple hereditary exostoses at least once during the growing years.

Anterior C1-2 osteochondroma presenting with dysphagia and sleep apnea

Spinal osteochondromas are rare, benign tumors of the bone. These tumors can manifest as solitary lesions or as part of a hereditary syndrome. Most spinal osteochondromas occur in the posterior cervical spine and can cause myelopathy or radiculopathy. Osteochondromas of the anterior cervical spine that cause respiratory or swallowing symptoms are rare. We present the unique case of a solitary osteochondroma of the anterior C1 vertebral arch causing obstructive sleep apnea and dysphagia in a 16-year-old female. The patient underwent resection of the tumor via a left anterior transcervical approach to the spine. The patient's symptoms resolved completely after surgery. To our knowledge, this is the first case of a sporadic osteochondroma arising from the anterior arch of the C1 vertebra causing dysphagia and obstructive apnea in a pediatric patient.