Intraosseous ganglion cyst within the L4 lamina causing spinal stenosis

Background context

There are rare reports of intraosseous ganglion cysts in the cervical spine. However, to our knowledge, there are no previous reports of these cysts occurring in the lumbar spine.

Purpose

To report a case of symptomatic lumbar spinal stenosis caused by an intraosseous ganglion cyst of the L4 lamina that communicated with the spinal canal.

Study design

Case report.

Methods

An 86-year-old woman was referred to our spine service for a 2-year history of anterior thigh and leg pain. Magnetic resonance imaging revealed a benign-appearing intraosseous cyst in the left L4 lamina communicating with a posterior epidural cyst at L4–L5 causing marked spinal stenosis. The patient was treated successfully with a laminectomy and resection.

Results

The patient underwent partial laminectomies of L4 and L5 preserving the interspinous ligaments between L5–S1 and L3–L4. The cyst was removed en bloc without violation of the cyst wall. Histopathologic examination revealed focal myxoid changes without a cellular lining of the cyst wall, confirming the diagnosis of intraosseous ganglion cyst.

Conclusions

This is the first report to describe an intraosseous ganglion cyst occurring in the lumbar spine. Although spinal stenosis is commonly a result of degenerative joint or disc disease, it occasionally may result from more obscure causes. This case illustrates a patient with an intraosseous ganglion cyst within the spinal lamina resulting in spinal stenosis, treated successfully with a laminectomy and resection.     

Twist technique for removal of spinal extradural arachnoid cyst: technical note

Study design

We document a spinal extradual arachnoid cyst treated by twist technique. The cyst is tightly adherent to the neural tissue or the dura, and the communication stalk is little or short.

Objective

To demonstrate the effectiveness of twist technique of closure of the communication stalk for the removal of spinal extradural arachnoid cyst.

Summary of background data

The standard treatment for a spinal extradural arachnoid cyst is complete excision of the cyst, followed by obliteration of the communication stalk and repair of the dural defect. To our knowledge, twist technique of the communication stalk for removal of spinal extradural arachnoid cyst has not been reported.

Methods

A 44-year-old woman presented with a 10-year history of pain and dysesthesia, initially in the posterior neck region and extending gradually to the distal portion of the right upper extremity. Pain and dysesthesia were exaggerated when she was lying down and relieved when standing or walking. She was diagnosed with an extradural arachnid cyst ranging from spinal regions T1 to T3 using MRI. Computerized tomography myelography revealed a mass located posterior to the spinal cord. Pooling of contrast medium was observed in the lesion indicating communication with the subarachnoid space. Laminectomy of the T1–T3 region was performed, preserving the spinous processes and the facet joints. A short communication stalk was found at the proximal root sleeve of right T3. This stalk was closed using twist technique.

Results

The patient experienced marked reduction of pain and dysesthesia after surgery, and the headache and blurred vision completely disappeared. Five days after the operation, she was discharged home in good condition. Postoperative 1 year later, the patient had completely recovered and resumed her normal life.

Conclusions

Twist technique can be seen safe and effective as another surgical option for spinal extradural arachnoid cysts containing a short stalk and dense fibrous adhesion with the dura mater.     

Intramedullary arachnoid cyst in association with cervical spondylosis: case report

Background context

Intramedullary spinal arachnoid cysts are considered to be very rare, and only 11 cases have been reported previously. Development of such a cyst in association with marked cervical spondylosis has not been reported until recently.

Purpose

Brief review of reported cases and debate on likely treatment strategy when such a cyst is associated with symptomatic spondylosis.

Study design

To report the first example of a cervicothoracic intramedullary arachnoid cyst along with a symptomatic cervical spondylosis.

Methods

Evaluation of quadriparesis in a 58-year-old female resulted in detection of a cervical spondylotic stenosis that was accompanied with an intramedullary cystic lesion. Parallel management of both pathologies was through a wide laminectomy extending from the lower edge of C3 to T2 with subsequent fenestration and partial resection of the cyst wall via an appropriate dorsal entry root zone myelotomy. Cervicothoracic instrumentation from C3 down to T2 was done to prevent postlaminectomy deformity.

Result

Histopathological findings were consistent with the diagnosis of arachnoid cyst. Postoperatively, the patient exhibited marked improvement in neurologic status.

Conclusion

Through the review of the current case, first example from the literature, we concluded that surgery should target toward the proper management of both pathologies in a single-stage operation.     

Detection of postoperative neurologic deficits using somatosensory-evoked potentials alone during posterior cervical laminoplasty

Background context

The use of neurophysiologic monitoring during anterior and posterior cervical decompression procedures in patients with spondylotic myelopathy remains controversial. The ideal neurophysiologic monitoring modality of choice is also highly debated.

Purpose

The purpose of this study was to evaluate the utility of neurophysiologic monitoring with only somatosensory-evoked potentials (SSEPs) in a consecutive series of laminoplasty procedures with regard to the detection of new postoperative neurologic deficits.

Study design

Retrospective case series.

Patient sample

Eighty consecutive patients who underwent a posterior cervical laminoplasty were reviewed.

Outcome measures

We analyzed intraoperative SSEP amplitude and latency changes from baseline with regard to the development of new postoperative neurologic deficits.

Methods

We retrospectively reviewed 80 patients who underwent a posterior cervical “open-door” laminoplasty with a standard SSEP neurophysiologic monitoring protocol. Intraoperative SSEP amplitude and latency changes from baseline (“alerts”) were analyzed with regard to the development of new postoperative neurologic deficits.

Results

Baseline SSEP values were obtained in all patients. There were five (6%) procedures that had SSEP alerts. All alerts occurred shortly after the lamina was hinged open. Four patients with SSEP alerts developed new postoperative neurologic deficits, including three unilateral upper extremity motor and sensory deficits and one complete spinal cord injury. In the immediate postoperative period, our experience with SSEP monitoring demonstrated 4 true-positive, 75 true-negative, and 1 false-positive monitoring results.

Conclusions

In this series of laminoplasty procedures, SSEP neurophysiologic monitoring had a high sensitivity and specificity for predicting new neurologic deficits in the early postoperative period. Somatosensory-evoked potentials are an effective tool for spinal cord monitoring when performing a posterior cervical laminoplasty procedure.     

Recapping T-saw laminocostotransversoplasty for ventral meningiomas in the thoracic region

Background  

Treatment of ventral lesions to the spinal cord in the thoracic spinal canal (e.g., meningiomas) are surgical challenges. Original or modified costotransversectomy has been commonly used for extirpation of such lesions. However, these techniques incur great loss of posterior elements followed by spinal instability that requires spinal fusion. The authors have developed a new surgical technique that combined the advantages of posterolateral exposures and recapping laminoplasty (recapping T-saw laminocostotransversoplasty). The purpose of this study was to examine the safety and effectiveness of this technique for surgical excision of ventrally located meningiomas in the thoracic region.     

Management of epididymal cysts in childhood

Background

A retrospective review was carried out to evaluate the clinical presentation of children with epididymal cysts (EC) and outcome of management at our institution.

Methods

There were 49 patients with EC in this series. The diagnosis of EC was made by physical examination and confirmed by ultrasound (US).

Results

The average age at presentation was 10.7 years (2 months–16 years). Scrotal mass (n: 22) and pain (n: 21) were the most frequent symptoms. Seven patients were lost to follow-up. The cysts were solitary in 32 patients and multiple in 10 patients. The mean value of cysts was 6.7 mm (2–20 mm). The cyst localisations were 22 in left, 16 in right, and bilateral in 4 patients. Complete involution of cysts was detected in 14 children. The average involution time was 11.2 months (1–37 months). In 20 cases, a decrease in cyst size was found. Cyst excision was performed in 8 patients with persistent scrotal pain or no cyst involution observed during follow-up.

Conclusion

Conservative management of epididymal cysts is practical. However, surgical excision is recommended in patients with intractable scrotal pain or if the cyst size does not seem to involute.     

Anterior cervical intradural arachnoid cyst,a rare cause of spinal cord compression: a case report with video systematic literature review

Purpose

Mostly seen at the thoracic level, arachnoid cysts are a very rare cause of cervical spinal cord compression. Generally treated by laminectomy and cyst fenestration, this approach does not allow removing the cyst in its entirety without manipulating the weakened spinal cord. The aim of this report is to present the case of a cervical intradural arachnoid cyst surgically removed by an anterior approach with corporectomy.

Methods

Here is the case of an 18-year-old amateur boxer presenting with a voluminous cervical intradural anterior arachnoid cyst, extending from C2 to C5. Symptoms were cervical pain, quadriparesis, and clumsiness of both arms which had appeared just after a traffic accident. An anterior approach was chosen, through a C5 corporectomy.

Results

The patient totally recovered from his sensitive symptoms at discharge and from his motor symptoms 6 weeks later. Early as well as 3-years post-operatively, MRI confirmed expansion of the spinal cord without any centro-medullar signal. The patient remained asymptomatic 3 years after surgery. Since the first report in 1974, 16 cases of symptomatic cervical intradural arachnoid cysts were treated via a posterior approach, one by MRI-guided biopsy, and one was re-operated on through an anterior approach. For 14 patients, their conditions had improved, while one died of pneumonia, one presented a condition worsened, and one had a stable neurological status.

Conclusion

Using an anterior approach is a safe procedure that allows resection of a cervical arachnoid cyst without any manipulation of the weakened spinal cord, while giving the best possible view.

     

Recapping T-saw laminoplasty for spinal cord tumors.

STUDY DESIGN: A prospective study of patients whose spinal cord tumors were managed surgically with a unique posterior method of removing and replacing the posterior spinal elements using T-saw ("recapping T-saw laminoplasty"). OBJECTIVES: To examine the safety and efficacy of the recapping T-saw laminoplasty technique for spinal canal surgery. SUMMARY OF BACKGROUND DATA: Laminectomy, laminoplasty, and/or laminotomy typically are used to approach intraspinal lesions. When removal and replacement of the posterior elements have been attempted, the effectiveness of the technique has been limited by the amount of bone sacrificed when using burrs or osteotomes. The authors thought to adapt a unique "threadwire saw" (T-saw) in these cases, because its use results in minimal bone loss. METHODS: Patients underwent recapping T-saw laminoplasty in the thoracic or lumbar spine for extirpation of spinal cord tumors. The T-saw was used for division of the posterior elements. After resection of the lesion, the excised laminae were replaced exactly in situ to their original anatomic position. The mean follow-up period was 47 months (range, 31-71 months). Patients were observed neurologically and radiologically. RESULTS: One to eight laminae were excised and replaced in 24 patients. Findings on computed tomography scans confirmed primary bony union in 23 patients by 6 months after surgery, and in one patient by 12 months after surgery. No complications such as postoperative spinal canal stenosis, facet arthrosis, or kyphosis were observed. CONCLUSIONS: Recapping laminoplasty afforded anatomic reconstruction of the vertebral arch after excision of spinal cord tumors. This procedure appears to warrant further evaluation as an alternative to wide laminectomies for exposure of intraspinal tumors.     

Management of complex giant spinal arachnoid cysts presenting with myelopathy

A giant spinal arachnoid cyst is an unusual cause of progressive epidural compressive syndrome. The authors describe 4 cases of a "complex" subtype of this lesion and discuss aspects of surgical management. The patients presented with progressive spastic paraparesis and were found to harbor extensive spinal extradural arachnoid cysts with multiple septations and significant paraspinal extensions. Extensive laminotomy and excision of the cyst along with its extensions were performed in all cases. Compared with previously indexed cases of surgically managed extensive spinal extradural arachnoid cysts, the cases reported here are unique because of their complex nature. Curative treatment consists of radical excision inclusive of the paraspinal extensions as well as closure of a dural defect, if found. A laminotomy or laminoplasty should be performed to avoid postoperative instability related to the extensive exposure. Extended follow-up and instrumentation may be required in select cases.     

Long-term outcomes after excision of choledochal cysts in a single institution: Operative procedures and late complications

Purpose

The purpose of this study was to evaluate long-term outcomes for a minimum of 3 years after cyst excision in children with choledochal cysts, focusing on the relationship between operative procedures and outcomes.

Methods

Between 1977 and 2008, 138 children underwent cyst excision. Follow-up results were obtained from 120 patients. Their mean age was 20.9 years (range 4–49). The mean interval between surgery and conducting the analysis was 16.6 years (range 3–34). These patients were divided into two groups based on their operative procedures: group A (1977–2000) comprising 76 patients who underwent cyst excision with hepaticojejunostomy below the hilum, and group B (2001–2008) comprising 44 patients who underwent excision of the extrahepatic bile duct from the confluence of the hepatic duct to near the level of the pancreatobiliary junction with wide hilar hepaticojejunostomy. When hepatic strictures were seen near the hilum, duct plasty was made. We evaluated the long-term outcomes in the two groups.

Results

Late complications were seen in a total of 18 patients (15.0%). In group A, 16 patients (21.1%) had late complications, which included cholangitis and/or hepatic stones in 9, stones in residual intrapancreatic cysts in 4, intestinal obstruction in 2, and pancreatitis in 1. Of these 16 patients, 12 patients (15.8%), including 7 with hepatic stones (6 IV-A and 1 Ic cysts), 4 with remnant intrapancreatic cysts, and 3 with intestinal obstruction underwent surgical intervention. In group B, none of the patients developed cholangitis, pancreatitis, or stone formation. However, 2 patients (4.5%) developed intestinal obstruction that required surgery.

Conclusions

Although a longer follow-up period is necessary, late complications were more frequent in group A than in group B patients and with type IV-A cysts. We believe that excision of the extrahepatic bile duct with wide hilar hepaticojejunostomy is essential for the prevention of postoperative complications.     

Spinal extradural arachnoid cyst

Background contextSpinal extradural arachnoid cysts are uncommon expanding lesions. Idiopathic arachnoid cysts are not associated with trauma or other inflammatory insults. If they enlarge, they usually present with progressive signs and symptoms of neural compression.PurposeTotal removal of the cyst and repair of the dural defect is the primary treatment for large thoracolumbar spinal extradural arachnoid cysts causing neurogenic claudication. Laminoplasty may prevent spinal deformities in long segmental involvement.Study designA clinical case was performed.Patient sampleWe report a case of 25-year-old man with 1-year history of progressive back pain radiating to both legs. His diagnosis was dorsal intraspinal extradural cystic lesion longing from the level of T11 to L2 on magnetic resonance imaging.Outcome MeasuresThe patient's pain levels were noted as he reported. Physiologic outcome was assessed on pre- and postoperative motor and sensory examination.MethodsThe patient underwent a T11–L2 laminotomy and radical cyst wall resection was performed. A small communication with the subarachnoid space was seen at the level of T12. It was sealed with tissue fibrinogen after repair with primary suture. Titanium miniplates were used for laminoplasty.ResultsFollow-up magnetic resonance imaging demonstrated cyst resolution, and neurologic examination revealed no sensory and motor deficit.ConclusionExtradural arachnoid cysts are primarily treated with total removal of the cyst wall and closure of the dural defect. Surgical treatment is curative for this rare lesion.     

Long-term follow-up of a case of aneurysmal bone cyst in the lumbar spine

Background context

Aneurysmal bone cyst (ABC) in the spine is relatively rare, so little is known about the natural history of the disease.

Purpose

The purpose of this study was to describe a spinal ABC that was followed for an extended period from lesion enlargement to spontaneous regression.

Study design

Case report.

Methods

A 63-year-old woman had a 1-year-long history of mild low back and bilateral leg pain without any significant neurologic deficits caused by lumbar spinal stenosis. At her first visit to our hospital, magnetic resonance imaging (MRI) showed a small cystic lesion on the left side of the L5 vertebral body. The patient's clinical symptom progression and MRI and computed tomography evaluations were reported for >13 years.

Results

After 6 years, the cystic lesion enlarged significantly and extended into the left pedicle and transverse process of the L5 vertebra. The lesion was diagnosed as an ABC based on multilocular cysts with fluid-fluid levels on MRI and bony septations on computed tomography. Thirteen years after the first visit, the lesion regressed spontaneously without a clear reason, such as biopsy or fracture, and most of the lesion was replaced by fatty marrow. The patient's symptoms stabilized without neurologic deterioration during the follow-up period.

Conclusions

Although spinal ABC is an expandable cystic lesion, we should consider that such a lesion in an elderly patient could spontaneously regress.     

Facet joint contact pressure is not significantly affected by ProDisc cervical disc arthroplasty in sagittal bending: a single-level cadaveric study

Background context

Total disc arthroplasty is a motion-preserving spinal procedure that has been investigated for its impact on spinal motions and adjacent-level degeneration. However, the effects of disc arthroplasty on facet joint biomechanics remain undefined despite the critical role of these posterior elements on guiding and limiting spinal motion.

Purpose

The goal was to measure the pressure in the facet joint in cadaveric human cervical spines subjected to sagittal bending before and after implantation of the ProDisc-C (Synthes Spine Company, L.P, West Chester, PA, USA).

Study design

A biomechanical study was performed using cadaveric human cervical spines during sagittal bending in the intact and implanted conditions.

Methods

Seven C2–T1 osteoligamentous cadaveric cervical spines were instrumented with a transducer to measure the C5–C6 facet pressure profiles during physiological sagittal bending, before and after implantation of a ProDisc-C at that level. Rotations of the index segment and global cervical spine were also quantified.

Results

The mean C5–C6 range of motion significantly increased (p=.009) from 9.6°±5.1° in the intact condition to 16.2°±3.6° after implantation. However, despite such changes in rotation, there was no significant difference in the facet contact pressure during extension between the intact (64±30 kPa) and implanted (44±55 kPa) conditions. Similarly, there was no difference in facet pressure developed during flexion.

Conclusions

Although implantation of a ProDisc-C arthroplasty device at the C5–C6 level increases angular rotations, it does not significantly alter the local facet pressure at the index level in flexion or extension. Using a technique that preserves the capsular ligament, this study provides the first direct measurement of cervical facet pressure in a disc arthroplasty condition.     

Dorsal thoracic spinal cord herniation: report of an unusual case and review of the literature

Background context

Spinal cord herniation is a rare but well-documented condition that has been associated with tethering through the dural defect. Both spinal cord herniation and cord tethering result in progressive myelopathy that can be improved or stabilized with surgical intervention. Most cases of herniation are caused by dural defects in the ventral or ventrolateral thoracic spine, rarely occurring through the dorsal dura. This is the first reported case of a spontaneous dorsal herniation.

Purpose

To describe a unique case of thoracic tethered cord resulting from a dorsal dural defect through which there is spinal cord herniation.

Study design

A case report and review of the literature.

Methods

A 55-year-old man presented with progressive low back pain, paresthesias, and weakness in his left lower extremity that was exacerbated by walking. Imaging revealed a dorsal dural defect with tethering and herniation of the spinal cord at T7.

Results

The patient underwent a T6–T7 laminoplasty to release the tethered cord and repair the dural defect. At 1-year follow-up, the patient noted improvement in strength and back spasticity.

Conclusions

Spinal cord herniation through a dural defect is an uncommon but important cause of symptomatic tethered cord in adults. Surgical intervention can significantly alter the course and prevent further disability.     

Dorsal root ganglion electrical stimulation promoted intertransverse process spinal fusion without decortications and bone grafting: a proof-of-concept study

Background context

Periosteum, endosteum, and bone are innervated by sensory nerves expressing calcitonin gene-related peptide (CGRP), which is a known osteoanabolic peptide and plays an important role in fracture healing and spinal fusion. Synthesis and release of CGRP are found in sensory neurons located in the dorsal root ganglions (DRGs) and can be upregulated by electrical stimulation (ES) at DRG.

Purpose

To prove our study hypothesis on the potential of precise ES at DRG through implantable microelectrical stimulation system (IMESS) for its effect on promoting spinal fusion in a rat model without decortications and bone grafting.

Study design

An experimental animal study.

Methods

A novel IMESS was developed for stimulating L4–L6 DRG in rats. Sixteen rats were used and divided equally into the control group without ES and the ES group, with a daily 20 minutes ES to DRG for 6 weeks. At the end of 6 weeks, radiography and microcomputed tomography were conducted to evaluate new bone formation and spinal fusion. Bilateral L4–L6 DRGs were harvested for immunohistochemistry and quantification of neurons with upregulated CGRP expression.

Results

In the ES group, rate of radiographic fusion with complete and uninterrupted bony bridging was 100% (8/8) at the right L4/L5 transverse processes and 75% (6/8) at the right L5/L6 transverse processes. Bony callus formation was absent at the left L4–L6 transverse processes in the ES group and in bilateral L4–L6 transverse processes in the control group.

Conclusions

We proved for the first time that precise ES at DRG through IMESS effectively promoted intertransverse process fusion in rat model without decortications and bone grafting. Electrical stimulation at DRG might be an attractive minimal invasive bioengineering approach and an alternative therapy for intertransverse process fusion that is increasingly being used for the treatment of degenerative spine disorders.     

Management of Neonatal Ovarian Cysts and its Effect on Ovarian Preservation

Background/Purpose

Management of asymptomatic neonatal ovarian cysts varies. Some surgeons advocate initial observation, while others recommend immediate operation depending on cyst size and complexity. This study aims to compare outcomes of initial observation versus primary surgery, focusing on incidence of postnatal torsion and ovarian preservation.

Methods

A retrospective study (1997–2012) of neonates with an ovarian mass was performed. Data on cyst size, ultrasound characteristics, clinical course, complications, and pathology were extracted.

Results

Thirty-seven neonates with asymptomatic ovarian cysts were identified (N = 25 observed, N = 12 primary surgery). Overall, 12/25 (48%) observed had successful cyst regression, including 3/8 (38%) cysts ≥ 50 mm and 6/15 (40%) complex. 13/25 patients (52%) underwent surgery for failure of cyst regression (11/13) or concern for interval torsion (2/13). Postnatal torsion occurred in 1/25 observation patients (4%), or 1/8 (13%) with cysts ≥ 50 mm. Overall rate of ovarian preservation between groups was not statistically different [6/8 (75%) observed versus 8/9 (89%) primary surgery; P = 0.577]. Pathology found viable ovarian tissue in all oophorectomy specimens (N = 3).

Conclusions

Postnatal torsion is rare. A period of observation spares half of neonates from an operation, without decreasing ovarian salvage. Initial management should consist of observation, regardless of size or complex characteristics. If operative intervention is necessary, ovary preserving techniques should be utilized.     

Factors affecting the occurrence of pulmonary embolism after spinal surgery: data from the national administrative database in Japan

Background context

Despite potentially devastating consequences, pulmonary embolism (PE) in patients undergoing spinal surgery remains poorly understood. To the best of our knowledge, few large studies have examined the prevalence and risk factors of PE after spinal surgery.

Purpose

To investigate the prevalence of symptomatic PE in patients undergoing elective spinal surgery and to identify clinical variables associated with the occurrence of postoperative PE.

Study design

A retrospective analysis of data abstracted from the diagnosis procedure combination (DPC) database, a nationally representative database in Japan.

Patient sample

We included all patients with a diagnosis of spinal canal stenosis, disc herniation, spondylosis, spondylolisthesis, trauma, metastatic tumor, or infection who underwent spinal surgery between July 1 and December 31 of 2007 and 2008, respectively.

Outcome measures

The primary end point was defined as the occurrence of postoperative PE during hospitalization. The secondary end point was in-hospital death after postoperative PE.

Methods

We analyzed the association between the occurrence of postoperative PE and clinical variables recorded in the DPC database, including age, sex, comorbidities, location of surgery, primary diagnosis, anterior/posterior approach, use of instrumentation, and duration of anesthesia.

Results

A total of 47,743 patients were identified. Of these, 50 (0.10%) developed PE and four died as a result of PE. Logistic regression analyses revealed that occurrence of PE was associated with older age (70 years or older; odds ratio [OR], 3.15; 95% confidence interval [CI], 1.15–8.69; p=.026) and longer anesthesia time (more than 360 minutes; OR, 2.19; 95% CI, 0.88–5.44; p=.092). Patients with trauma were significantly more likely to have a PE than those with spinal canal stenosis (0.27% vs. 0.09%; OR, 2.86; 95% CI, 1.14–7.18; p=.026).

Conclusions

This retrospective analysis of a nationally representative database identified older age, longer anesthesia time, and spinal trauma as risk factors for increased incidence of postoperative PE. Surgeons should be aware of the increased risk of postoperative PE in these subgroups of patients.     

Spinal extradural meningeal cyst with spinal stenosis

STUDY DESIGN: Case report. OBJECTIVE: To present a rare pathology causing a common disease. SETTING: Spine unit of the orthopaedic surgery department of a university hospital in Berlin/Germany. CASE REPORT: A 39-year-old female with an intraspinal extradural arachnoid cyst of the lumbar spine presented with intermittent radiating lumbar pain. The magnetic resonance imaging (MRI) showed a dorsal spinal extradural arachnoid cyst at L3/4. After wide laminotomy L3, operative cyst resection and stabilisation at L3/4 by posterior lumbar interbody fusion (PLIF), major symptom relief occurred. CONCLUSION: Spinal extradural arachnoid cysts are a rare entity causing low back pain and intermittent radicular syndromes. They can be caused by arachnoid herniation through dural weak spots which are hereditary or occur after trauma. A ball-valve mechanism promotes growth. The main diagnostic tool for spinal extradural cysts is the MRI scan. Additionally, myelography is helpful to demonstrate fluid communication. Complete surgical removal of the cyst should be attempted to reduce risk of recurrence. If extensive decompression is needed for the surgical approach causing segmental instability, interbody fusion is recommended. The outcome depends on age, duration and degree of neurological damage.     

An unexpected complication of occipitocervical stabilization surgery: retropharyngeal hematoma

Background context

To report a unique case of an unexpected complication of occipitocervical stabilization surgery that is retropharyngeal hematoma (RH).

Purpose

Postoperative RH is a very rare complication and has never been reported after posterior occipitocervical surgery.

Study design

Case report.

Methods

A 44-year-old woman being treated for rheumatoid arthritis for 20 years was admitted to our hospital in a wheelchair with the complaints of neck pain and weakness in both upper and lower extremities. She was diagnosed with basilar invagination, and occipitocervical (C0–C5) transpedicular fixation with osteosynthesis using iliac autograft was performed. The airway was seen as obstructed after extubation. The airway was maintained with laryngeal mask, and computed tomography revealed an RH. Emergent tracheotomy was performed. The patient was decannulated because of the resorption of RH after 10 days and was discharged.

Conclusion

This patient is the first patient, to our knowledge, to be reported for unexplained RH after cervical posterior spinal surgery.