• Journal of Korean Neurosurgical Society
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• v.58 no.4
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• pp.357-362
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• 2015

Objective : To investigate risk factors for S1 screw loosening after lumbosacral fusion, including spinopelvic parameters and paraspinal muscles. Methods : We studied with 156 patients with degenerative lumbar disease who underwent lumbosacral interbody fusion and pedicle screw fixation including the level of L5-S1 between 2005 and 2012. The patients were divided into loosening and non-loosening groups. Screw loosening was defined as a halo sign larger than 1 mm around a screw. We checked cross sectional area of paraspinal muscles, mean signal intensity of the muscles on T2 weight MRI as a degree of fatty degeneration, spinopelvic parameters, bone mineral density, number of fusion level, and the characteristic of S1 screw. Results : Twenty seven patients showed S1 screw loosening, which is 24.4% of total. The mean duration for S1 screw loosening was $7.3{\pm}4.1$ months after surgery. Statistically significant risk factors were increased age, poor BMD, 3 or more fusion levels (p<0.05). Among spinopelvic parameters, a high pelvic incidence (p<0.01), a greater difference between pelvic incidence and lumbar lordotic angle preoperatively (p<0.01) and postoperatively (p<0.05). Smaller cross-sectional area and high T2 signal intensity in both multifidus and erector spinae muscles were also significant muscular risk factors (p<0.05). Small converging angle (p<0.001) and short intraosseous length (p<0.05) of S1 screw were significant screw related risk factors (p<0.05). Conclusion : In addition to well known risk factors, spinopelvic parameters and the degeneration of paraspinal muscles also showed significant effects on the S1 screw loosening.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.61-70
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• 2019

Objective : Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy. Methods : Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months. Results : The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected. Conclusion : The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior loadbearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

• Journal of Korean Neurosurgical Society
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• v.62 no.4
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• pp.432-441
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• 2019

Objective : Few studies have reported direct comparative data of lumbar spine angles between direct lateral interbody fusion (DLIF) and oblique lateral interbody fusion (OLIF). The purpose of this study was to investigate the clinical and radiological outcomes of DLIF and OLIF, and determine influential factors. Methods : The same surgeon performed DLIF from May 2011 to August 2014 (n=201) and OLIF from September 2014 to September 2016 (n=142). Radiological parameters, cage height, cage angle (CA), cage width (CW), and cage location were assessed. We checked the cage location as the distance (mm) from the anterior margin of the disc space to the anterior metallic indicator of the cage in lateral images. Results : There were significant differences in intervertebral foramen height (FH; $22.0{\pm}2.4$ vs. $21.0{\pm}2.1mm$, p<0.001) and sagittal disc angle (SDA; $8.7{\pm}3.3$ vs. $11.3{\pm}3.2^{\circ}$, p<0.001) between the DLIF and OLIF groups at 7 days postoperatively. CA ($9.6{\pm}3.0$ vs. $8.1{\pm}2.9^{\circ}$, p<0.001) and CW ($21.2{\pm}1.6$ vs. $19.2{\pm}1.9mm$, p<0.001) were significantly larger in the OLIF group compared to the DLIF group. The cage location of the OLIF group was significantly more anterior than the DLIF group ($6.7{\pm}3.0$ vs. $9.1{\pm}3.6mm$, p<0.001). Cage subsidence at 1 year postoperatively was significantly worse in the DLIF group compared to the OLIF group ($1.0{\pm}1.5$ vs. $0.4{\pm}1.1mm$, p=0.001). Cage location was significantly correlated with postoperative FH (${\beta}=0.273$, p<0.001) and postoperative SDA (${\beta}=-0.358$, p<0.001). CA was significantly correlated with postoperative FH (${\beta}=-0.139$, p=0.044) and postoperative SDA (${\beta}=0.236$, p=0.001). Cage location (${\beta}=0.293$, p<0.001) and CW (${\beta}=-0.225$, p<0.001) were significantly correlated with cage subsidence. Conclusion : The cage location, CA, and CW seem to be important factors which result in the different-radiological outcomes between DLIF and OLIF.

• Journal of Korean Neurosurgical Society
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• v.43 no.6
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• pp.294-299
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• 2008

Objective : To evaluate the clinical characteristics and surgical outcomes of the patients with cervical spondylotic myelopathy associated with athetoid cerebral palsy. Methods : The authors reviewed the clinical and neurodiagnostic findings, surgical managements and outcomes in six consecutive patients with cervical spondylotic myelopathy associated with athetoid cerebral palsy who had been treated with surgical decompression and fusion procedures between January 1999 and December 2005. The mean age of the 6 patients (four women and two men) at the time of surgery was 42.8 years (range, 31-55 years). The mean follow-up period was 56.5 months (range, 17-112 months). The neurological outcome was evaluated before and after operations (immediately, 6 months after and final follow-up) using grading systems of the walking ability, brachialgia and deltoid power. Results : At immediate postoperative period, after 6 months, and at final follow-up, all patients showed apparent clinical improvements in walking ability, upper extremity pain and deltoid muscle strength. Late neurological deterioration was not seen during follow-up periods. There were no serious complications related to surgery. Conclusion : Surgical decompression and stabilization in patients with cervical spondylotic myelopathy associated with athetoid cerebral palsy have been challenging procedure up to now. Our results indicate that early diagnosis and appropriate surgical procedure can effectively improve the clinical symptoms and neurological function in patients with cervical spondylotic myelopathy and athetoid cerebral palsy, even in those with severe involuntary movements.

• Journal of Korean Neurosurgical Society
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• v.48 no.2
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• pp.129-133
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• 2010

Objective : The use of segmental instrumentation technique using pedicle screw has been increasingly popular in recent years owing to its biomechanical stability. Recently, intralaminar screws have been used as a potentially safer alternative to traditional fusion constructs involving fixation of C2 and the cervicothoracic junction including C7. However, to date, there have been few clinical series of C7 laminar screw fixation in the literature. Thus, the purpose of this study is to report our clinical experiences using C7 laminar screw and the early clinical outcome of this rather new fixation technique. Methods : Thirteen patients underwent C7 intralaminar fixation to treat lesions from trauma or degenerative disease. Seventeen intralaminar screws were placed at C7. The patients were assessed both clinically and radiographically with postoperative computed tomographic scans. Results : There was no violation of the screw into the spinal canal during the procedure and no neurological worsening or vascular injury from screw placement. The mean clinical and radiographic follow up was about 19 months, at which time there were no cases of screw pull-out, screw fracture or non-union. Complications included two cases of dorsal breech of intralaminar screw and one case of postoperative infection. Conclusion : Intralaminar screws can be potentially safe alternative technique for C7 fixation. Even though this technique cannot be used in the cases of C7 laminar fracture, large margin of safety and the ease of screw placement create a niche for this technique in the armamentarium of spine surgeons.

• Journal of Korean Neurosurgical Society
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• v.58 no.1
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• pp.50-53
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• 2015

Objective : The purpose of this study was to evaluate radiographic/clinical outcomes of adolescent idiopathic scoliosis (AIS) patients treated by a Korean neurosurgeon. Methods : Ten AIS patients were treated by a single neurosurgeon between January 2011 and September 2013 utilizing segmental instrumentation with pedicle screws. Basic demographic information, curve pattern by Lenke classification, number of levels treated, amount of correction achieved, radiographic/clinical outcomes [by Scolisis Resarch Society (SRS-22r) questionnaire] and complications were evaluated to determine the surgical results. Pulmonary function test was utilized to assess forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) before and after surgery. Results : The average percentage of correction of the major structural curve was 73.6% (ranged from 64% to 81.5%). Preoperative and final postoperative absolute FVC averaged 3.03 L and 3.76 L (0.73 L increase, p=0.046), and absolute FEV1 averaged 2.63 L and 3.49 L (0.86 L increase, p=0.021). Preoperative and final postoperative average self-image and function scores of SRS-22r were, $2.6{\pm}0.5$, $3.3{\pm}0.1$, $4.0{\pm}0.5$, and $4.6{\pm}0.0$, respectively. There was a significant improvement of the self-image and function scores of SRS-22r questionnaires before and after surgery (p<0.05). There was no case of neurological deficit, infection and revision for screw malposition. One patient underwent a fusion extension surgery for shoulder asymmetry. Conclusion : Radiographic/clinical outcomes of AIS patients treated by a Korean neurosurgeon were acceptable. Fundamental understanding of pediatric spinal deformity is essential for the practice of AIS surgery.