Soo Eon Lee

Dural tear and resultant cerebrospinal fluid leaks after cervical spinal trauma

PurposeTraumatic cervical spinal cord injuries (SCIs) frequently develop dural tears and resultant cerebrospinal fluid (CSF) leaks. They are not usually identified with advanced imaging, and there are no reports on managing CSF leaks after cervical trauma. Hence, the authors evaluated the incidence of CSF leaks after cervical SCIs and described how to predict and manage CSF leaks.MethodsAn observational retrospective study was done confirming intraoperative CSF leaks among 53 patients with anterior cervical surgery after cervical spine trauma between 2004 and 2011.ResultsSeven patients (13.2xa0%) had dural tears and resultant CSF leaks intraoperatively (M:F ratio of 6:1; mean age, 44.7xa0years). An initial poor American Spinal Injury Association (ASIA) scale was significantly associated with CSF leaks (pxa0=xa00.009). From magnetic resonance imaging (MRI), disruption of the ligamentum flavum was correlated with CSF leaks (pxa0=xa00.02). Intraoperative application of fibrin glue on the operated site, postoperative management through the early removal of the wound drain within the first 24xa0h and early rehabilitation were performed in patients with CSF leaks without perioperative insertion of a lumbar drain. During the follow-up period, none of the patients developed CSF-leak-related complications.ConclusionThe incidence of CSF leaks after traumatic cervical SCI is relatively higher than that of degenerative cervical spinal surgery. An initial poor neurological status and disruption of the ligamentum flavum on the MRI in patients were predictable factors of dural tears and CSF leaks.

Correlation between cervical lordosis and adjacent segment pathology after anterior cervical spinal surgery

PurposeTo evaluate the incidence and risk factors for adjacent segment pathology (ASP) after anterior cervical spinal surgery.MethodsFourteen patients (12 male, mean age 47.1xa0years) who underwent single-level cervical disk arthroplasty (CDA group) and 28 case-matched patients (24 male, mean age 53.6xa0years) who underwent single-level anterior cervical discectomy and fusion (ACDF group) were included. Presence of radiologic ASP (RASP) was based on observed changes in anterior osteophytes, disks, and calcification of the anterior longitudinal ligament on lateral radiographs.ResultsThe mean follow-up period was 43.4xa0months in the CDA group and 44.6xa0months in the ACDF group. At final follow-up, ASP was observed in 5 (35.7xa0%) CDA patients and 16 (57.1xa0%) ACDF patients (pxa0=xa00.272). The interval between surgery and ASP development was 33.8xa0months in the CDA group and 16.3xa0months in the ACDF group (pxa0=xa00.046). The ASP risk factor analysis indicated postoperative cervical angle at C3–7 being more lordotic in non-ASP patients in both groups. Restoration of lordosis occurred in the CDA group regardless of the presence of ASP, but heterotopic ossification development was associated with the presence of ASP in the CDA group. And the CDA group had significantly greater clinical improvements than those in the ACDF group when ASP was present.ConclusionIn both CDA and ACDF patients, RASP developed, but CDA was associated with a delay in ASP development. A good clinical outcome was expected in CDA group, even when ASP developed. Restoration of cervical lordosis was an important factor in anterior cervical spine surgery.

Different Surgical Approaches for Spinal Schwannoma: A Single Surgeon's Experience with 49 Consecutive Cases.

OBJECTIVEnComparing different surgical approaches for spinal schwannoma, the safety and efficacy of the minimally invasive surgery (MIS) approach were demonstrated, and a suitable indication for each surgical approach was analyzed.nnnMETHODSnThis study comprised 49 consecutive patients with intradural extramedullary schwannoma who underwent surgical resection: 31 patients via MIS approach (MIS group; 6 patients via a muscle-splitting approach using a tubular retractor and 25 patients via unilateral hemilaminectomy preserving the contralateral paraspinal muscle) and 18 patients via total laminectomy (TL group). Medical records including perioperative data and radiologic data were reviewed.nnnRESULTSnOn initial magnetic resonance imaging, the mean maximal sagittal diameter of the tumor was 23.9 mm in the MIS group and 26.9 mm in the TL group, and the mean maximal axial diameter was 16.1 mm in the MIS group and 22.8 mm in the TL group (P = 0.452 and P = 0.011, respectively). The foraminal extension of tumor was identified in 8 patients in the MIS group and 9 patients in the TL group (P = 0.081). The tumor location was the lumbar spine in 20 patients in the MIS group and the cervicothoracic spine in 17 patients in the TL group (P = 0.001). Intraoperatively, all tumors in the MIS group could be totally resected with reduced operative time and blood loss. During the follow-up period of 38.2 months in the MIS group and 51.2 months in the TL group, the clinical improvement was not different between the surgical approaches (P = 0.332).nnnCONCLUSIONSnSafe and complete resection of intradural extramedullary schwannoma was obtained through the MIS approach. Regardless of sagittal extension of the tumor, a schwannoma with an axial diameter of 16 mm located in the lumbar spine can be effectively treated with the MIS approach, including foraminal extension.

Adverse Effect of Trauma on Neurologic Recovery for Patients with Cervical Ossification of the Posterior Longitudinal Ligament

Study Design Retrospective study. Objective Minor trauma, even from a simple fall, can often cause cervical myelopathy, necessitating surgery in elderly patients who may be unaware of their posterior longitudinal ligament ossification (OPLL). The aim of this study is to determine the influence of trauma on the neurologic course in patients who have undergone surgery for cervical OPLL. Methods Patients who underwent surgery due to OPLL were divided by trauma history and compared (34 in the trauma group; 70 in the nontrauma group). Results Ground falls were the most common type of trauma (20 patients, low-energy injuries), but 23 patients developed new symptoms after a trauma. Although the symptom duration (17.68 months) was shorter, the Japanese Orthopedic Association (JOA) score and the Nurick scale showed lower values in the trauma group. Trauma histories led patients to earlier hospital visits. Initial JOA scores were associated with a good recovery status upon the last follow-up in both the groups. The narrowest diameter of the spinal canal showed different radiologic parameters: 5.78u2009mm in the trauma group and 6.52u2009mm in the nontrauma group. Conclusion Minor trauma can cause the unexpected development of new symptoms in patients unaware of cervical OPLL. Patients with a history of trauma had lower initial JOA scores and showed a narrower spinal canal compared with a nontrauma group. The initial JOA scores were correlated with a good recovery status upon the last follow-up.

Surgical outcomes in patients with mild symptoms, but severely compressed spinal cord from cervical ossification of the posterior longitudinal ligament.

Surgical treatment is indicated in patients with moderate to severe myelopathy from cervical ossification of the posterior longitudinal ligaments (OPLL), but undertaking prophylactic surgery for asymptomatic or mildly symptomatic patients with a severely compressed spinal cord is debatable. Patients with <8mm space available in the spinal canal on CT scan, were divided into groups I (mild symptoms, Japanese Orthopedic Association (JOA) score range 15-16) and II (moderate to severe symptoms, JOA score <14). Medical charts including operative records were reviewed to obtain preoperative, perioperative, and final postoperative follow-up data. Group I included 24 patients (20 men, mean age 52.42years), and Group II included 46 patients (33 men, mean age 54.67years). Compared to Group II, Group I had a shorter preoperative symptom duration (19.21 vs. 38.23months, p=0.046) and a more favorable JOA score at final follow-up (p=0.007). The mean numbers of OPLL-involved segments were similar (Group I 2.96, Group II 3.09; p=0.773) as were the mean numbers of operated segments (Group I 2.71, Group II 3.35; p=0.076). Perioperative blood loss, operation duration, and hospital stay duration were significantly more favorable in Group I than in Group II. The numbers of surgery-related complications in the two groups were similar. Early surgical treatment for a favorable neurologic recovery with a low perioperative risk can be recommended in patients with severely compressed spinal cord from cervical OPLL who present with mild arm numbness. Surgery-related complications, however, should be carefully monitored regardless of symptom severity.

Risk Prediction for Development of Traumatic Cervical Spinal Cord Injury without Spinal Instability

Study Design Retrospective comparative study. Objective A narrow spinal canal is an important risk factor for predicting a spinal cord injury (SCI); however, the radiologic parameters have not been fully established. The authors conducted a comparative study to forecast SCI risk by determining a predictive spinal canal diameter (SCD) cutoff value from magnetic resonance image (MRI) in the Korean population. Methods On T2-weighted MRI of the cervical spine, the SCD at the pedicle (SCDpedicle) and the intervertebral disk level (SCDdisk) were measured in patients with SCI without spinal instability and in healthy subjects. Additionally, the vertebral body diameter (Dvertebral body) and intervertebral disk diameter (Dintervertebral disk) were measured, and the two ratios (SCDpedicle to Dvertebral body and SCDdisk to Dintervertebral disk) were calculated. In the SCI group, the extent of high signal intensity on the T2-weighted midsagittal MRI was determined. Results The data obtained from 20 patients in the SCI group (18 men, mean age 61.35 years) and 65 individuals in the control group (47 men, mean age 57.05 years) was compared. All the parameters including the SCD and the calculated ratios were significantly smaller in the SCI group than in the control group. Among them, the area under the receiver operating curve (AUC) value for the SCDdisk-to-Dintervertebral disk ratio at C2–C3, with a cutoff ratio value of 0.59, provided the greatest positive predictive value. A low SCDdisk-to-Dintervertebral disk ratio at C4–C5 and the presence of >40u2009mm of high signal intensity on the MRI were related with the presence of complete SCI. Conclusion Because the C2–C3 level is relatively wide compared with the subaxial cervical spine, a small ratio at C2–C3 provided the greatest positive predictive value in SCI. Complete SCI is associated with a small SCDdisk-to-Dintervertebral disk ratio at C4–C5 and with extensive high signal intensity on MRI.

Surgical Outcomes of the Ossification of the Posterior Longitudinal Ligament According to the Involvement of the C2 Segment

OBJECTIVEnThe complex structure around the upper cervical spine makes surgical treatment difficult. the present study aimed to analyze how patients with ossification of the longitudinal ligament (OPLL) involving the C2 were managed and to compare the surgical outcomes according to the C2 involvement.nnnMETHODSnNinety-five patients with cervical OPLL who underwent surgical treatment were divided into C2 involvement (C2+ group, 40 patients) or none (C2- group, 55 patients). In the C2+ group, subanalysis was conducted to according to the C2 surgery (C2 surgery+ group, 14 patients).nnnRESULTSnAll patients had a minimum of 1 year of follow-up with a mean of 51.36 months. The most common location of the narrowest space available for the spinal cord was C2 and C5 in the C2+ and C2- groups, respectively. In the C2+ group, a longer OPLL with thickened diameter was radiographically demonstrated, but clinical outcomes were not different from the C2- group. In the C2 surgery+ group, the narrowest spinal cord was common in the C2 (50.0%), and an extension of the signal change of spinal cord to the C2 was observed in 4 patients, showing a statistical difference. C2 surgery was performed in all patients using the posterior approach and it did not result in different clinical outcomes or surgery-related complications. An anterior surgical approach was deemed risky given the chance of the development of complications.nnnCONCLUSIONSnBoth of C2 involvement from OPLL and surgery including the C2 did not affect clinical outcomes. The posterior decompressive surgery is safer and more effective than the anterior approach regarding the development of surgery-related complications.

Difference in canal encroachment by the fusion mass between anterior cervical discectomy and fusion with bone autograft and anterior plating, and stand-alone cage

We conducted a prospective randomized study comparing stand-alone cage and bone autograft and plate implants in anterior cervical discectomy and fusion (www.clinicaltrials.gov, NCT01011569). Our interim analysis showed autologous bone graft with plating was superior to a stand-alone cage for segmental lordosis. During this analysis, we noted a difference in canal encroachment by the fusion mass between the two fusion groups. A narrow cervical spinal canal is an important factor in the development of cervical spondylotic myelopathy, therefore this unexpected potential risk of spinal cord compression necessitated another interim analysis to investigate whether there was a difference in canal encroachment by the fusion mass between the two groups. Patients had a minimum 1year of follow-up. The Neck Disability Index, neck and arm pain Visual Analog Scales and lateral radiographs, including bone fusion patterns, were evaluated. Twenty-seven (16 males, 11 females, mean age 54.8years) and 31 (24 males, seven females, mean age 54.5years) patients were in the cage and plate group, respectively. Both groups improved after surgery. Fusion began at 2.6months and 1.3months and finished at 6.7months and 4.0months in 24 (88.9%) and 28 (90.3%) patients in the cage and plate group, respectively. Encroachment into the spinal canal by the fusion mass was significantly different between the fusion types, occuring in 21 (77.8%) patients in the cage group versus six (19.4%) in the plate group (p=0.003). There was a high incidence of spinal canal encroachment by the fusion mass in the stand-alone cage group, possibly limiting use in narrow spinal canals.

Spinal Epidural Arteriovenous Hemangioma Mimicking Lumbar Disc Herniation

A spinal epidural hemangioma is rare. In this case, a 51 year-old female patient had low back pain and right thigh numbness. She was initially misdiagnosed as having a ruptured disc with possible sequestration of granulation tissue formation due to the limited number of spinal epidural hemangiomas and little-known radiological findings. Because there are no effective diagnostic tools to verify the hemangioma, more effort should be put into preoperative imaging tests to avoid misdiagnosis and poor decisions).

Clinical Experiences of Non-fusion Dynamic Stabilization Surgery for Adjacent Segmental Pathology after Lumbar Fusion.

Background As an alternative to spinal fusion, non-fusion dynamic stabilization surgery has been developed, showing good clinical outcomes. In the present study, we introduce our surgical series, which involves non-fusion dynamic stabilization surgery for adjacent segment pathology (ASP) after lumbar fusion surgery. Methods Fifteen patients (13 female and 2 male, mean age of 62.1 years) who underwent dynamic stabilization surgery for symptomatic ASP were included and medical records, magnetic resonance images (MRI), and plain radiographs were retrospectively evaluated. Results Twelve of the 15 patients had the fusion segment at L4-5, and the most common segment affected by ASP was L3-4. The time interval between prior fusion and later non-fusion surgery was mean 67.0 months. The Visual Analog Scale and Oswestry Disability Index showed values of 7.4 and 58.5% before the non-fusion surgery and these values respectively declined to 4.2 and 41.3% postoperatively at 36 months (p=0.027 and p=0.018, respectively). During the mean 44.8 months of follow-up, medication of analgesics was also significantly reduced. The MRI grade for disc and central stenosis identified significant degeneration at L3-4, and similar disc degeneration from lateral radiographs was determined at L3-4 between before the prior fusion surgery and the later non-fusion surgery. After the non-fusion surgery, the L3-4 segment and the proximal segment of L2-3 were preserved in the disc, stenosis and facet joint whereas L1-2 showed disc degeneration on the last MRI (p=0.032). Five instances of radiologic ASP were identified, showing characteristic disc-space narrowing at the proximal segments of L1-2 and L2-3. However, no patient underwent additional surgery for ASP after non-fusion dynamic stabilization surgery. Conclusion The proposed non-fusion dynamic stabilization system could be an effective surgical treatment for elderly patients with symptomatic ASP after lumbar fusion.