• Journal of Korean Neurosurgical Society
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• v.49 no.5
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• pp.267-272
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• 2011

Objective : Although iliac crest autograft is the gold standard for lumbar fusion, the morbidity of donor site leads us to find an alternatives to replace autologous bone graft. Ceramic-based synthetic bone grafts such as hydroxyapatite (HA) and b-tricalcium phosphate (b-TCP) provide scaffolds similar to those of autologous bone, are plentiful and inexpensive, and are not associated with donor morbidity. The present report describes the use of Polybone$^{(R)}$ (Kyungwon Medical, Korea), a beta-tricalcium phosphate, for lumbar posterolateral fusion and assesses clinical and radiological efficacy as a graft material. Methods : This study retrospectively analyzed data from 32 patients (11 men, 21 women) who underwent posterolateral fusion (PLF) using PolyBone$^{(R)}$ from January to August, 2008. Back and leg pain were assessed using a Numeric Rating Scale (NRS), and clinical outcome was assessed using the Oswestry Disability Index (ODI). Serial radiological X-ray follow up were done at 1, 3, 6 12 month. A computed tomography (CT) scan was done in 12 month. Radiological fusion was assessed using simple anterior-posterior (AP) X-rays and computed tomography (CT). The changes of radiodensity of fusion mass showed on the X-ray image were analyzed into 4 stages to assess PLF status. Results : The mean NRS scores for leg pain and back pain decreased over 12 months postoperatively, from 8.0 to 1.0 and from 6.7 to 1.7, respectively. The mean ODI score also decreased from 60.5 to 17.7. X-rays and CT showed that 25 cases had stage IV fusion bridges at 12 months postoperatively (83.3% success). The radiodensity of fusion mass on X-ray AP image significantly changed at 1 and 6 months. Conclusion: The present results indicate that the use of a mixture of local autologous bone and PolyBone$^{(R)}$ results in fusion rates comparable to those using autologous bone and has the advantage of reduced morbidity. In addition, the graft radiodensity ratio significantly changed at postoperative 1 and 6 months, possibly reflecting the inflammatory response and stabilization.

• Journal of Korean Neurosurgical Society
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• v.67 no.3
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• pp.354-363
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• 2024

Objective : This study aims to determine the optimal dose of recombinant-human bone morphogenic protein-2 (rhBMP-2) for successful bone fusion in minimally invasive lateral lumbar interbody fusion (MIS LLIF). Previous studies show that rhBMP is an effective alternative to autologous iliac crest bone graft, but the optimal dose remains uncertain. The study analyzes the fusion rates associated with different rhBMP doses to provide a recommendation for the optimal dose in MIS LLIF. Methods : Ninety-three patients underwent MIS LLIF using demineralized bone matrix (DBM) or a mixture of rhBMP-2 and DBM as fusion material. The group was divided into the following three groups according to the rhBMP-2 usage : group A, only DBM was used (n=27); group B, 1 mg of rhBMP-2 per 5 mL of DBM paste (n=41); and group C, 2 mg of rhBMP-2 per 5 mL of DBM paste (n=25). Demographic data, clinical outcomes, postoperative complication and fusion were assessed. Results : At 12 months post-surgery, the overall fusion rate was 92.3% according to Bridwell fusion grading system. Groups B and C, who received rhBMP-2, had significantly higher fusion rates than group A, who received only DBM. However, there was no significant increase in fusion rate when the rhBMP-2 dosage was increased from group B to group C. The groups B and C showed significant improvement in back pain and Oswestry disability index compared to the group A. The incidence of screw loosening was decreased in groups B and C, but there was no significant difference in the occurrence of other complications. Conclusion : Usage of rhBMP-2 in LLIF surgery leads to early and increased final fusion rates, which can result in faster pain relief and return to daily activities for patients. The benefits of using rhBMP-2 were not significantly different between the groups that received 1 mg/5 mL and 2 mg/5 mL of rhBMP-2. Therefore, it is recommended to use 1 mg of rhBMP-2 with 5 mL of DBM, taking both economic and clinical aspects into consideration.

• Journal of Korean Neurosurgical Society
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• v.60 no.2
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• pp.174-180
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• 2017

Objective : Proximal junctional kyphosis (PJK) is radiologic finding, and is defined as kyphosis of >$10^{\circ}$ at the proximal end of a construct. The aim of this study is to identify factors associated with PJK after segmental spinal instrumented fusion in adults with spinal deformity with a minimum follow-up of 2 years. Methods : A total of 49 cases of adult spinal deformity treated by segmental spinal instrumented fusion at two university hospitals from 2004 to 2011 were enrolled in this study. All enrolled cases included at least 4 or more levels from L5 or the sacral level. The patients were divided into two groups based on the presence of PJK during follow-up, and these two groups were compared to identify factors related to PJK. Results : PJK was observed in 16 of the 49 cases. Age, sex and mean follow-up duration were not statistically different between two groups. However, mean bone marrow density (BMD) and mean back muscle volume at the T10 to L2 level was significantly lower in the PJK group. Preoperatively, the distance between the C7 plumb line and uppermost instrumented vertebra (UIV) were no different in the two groups, but at final follow-up a significant intergroup difference was observed. Interestingly, spinal instrumentation factors, such as, receipt of a revision operation, the use of a cross-link, and screw fracture were no different in the two groups at final follow-up. Conclusion : Preoperative BMD, sagittal imbalance at UIV, and thoracolumbar muscle volume were found to be strongly associated with the presence of PJK.

• Journal of Korean Neurosurgical Society
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• v.61 no.4
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• pp.494-502
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• 2018

Objective : The loosening of pedicle screws (PS) is one of the frequent problems of spinal surgery in the patients with osteoporosis. Previous studies had revealed that intermittent injection of teriparatide could reduce PS loosening by improving bone mass and quality when their patients took parathyroid hormone for a considerable duration before surgery. However, although the teriparatide is usually used after spine surgery in most clinical situations, there was no report on the efficacy of teriparatide treatment started after spine surgery. The purpose of this retrospective study was to examine the efficacy of teriparatide treatment started immediately after lumbar spinal surgery to prevent pedicle screw loosening in patients with osteoporosis. Methods : We included 84 patients with osteoporosis and degenerative lumbar disease who underwent transforaminal interbody fusion and PS fixation and received parathyroid hormone or bisphosphonate (BP) postoperatively. They were divided into teriparatide group (daily injection of $20{\mu}g$ of teriparatide for 6 months, 33 patients, 172 screws) and BP group (weekly oral administration of 35 mg of risedronate, 51 patients, 262 screws). Both groups received calcium (500 mg/day) and cholecalciferol (1000 IU/day) together. The screw loosening was evaluated with simple radiographic exams at 6 and 12 months after the surgery. We counted the number of patients with PS loosening and the number of loosened PS, and compared them between the two groups. Clinical outcomes were evaluated using visual analog scale (VAS) and Oswestry disability index (ODI) preoperatively, and at 12 months after surgery. Results : There was no significant difference in the age, sex, diabetes, smoking, bone mineral density, body mass index, and the number of fusion levels between the two groups. The number of PS loosening within 6 months after surgery did not show a significant difference between the teriparatide group (6.9%, 12/172) and the BP group (6.8%, 18/272). However, during 6-12 months after surgery, it was significantly lower in the teriparatide group (2.3%, 4/172) than the BP group (9.2%, 24/272) (p<0.05). There was no significant difference in the number of patients showing PS loosening between the teriparatide and BP groups. The teriparatide group showed a significantly higher degree of improvement of the bone mineral density (T-score) than that of BP group (p<0.05). There was no significant difference in the pre- and post-operative VAS and ODI between the groups. Conclusion : Our data suggest that the teriparatide treatment starting immediately after lumbar spinal fusion surgery could reduce PS loosening compared to BP.

• Journal of Trauma and Injury
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• v.25 no.4
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• pp.278-282
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• 2012

An esophageal perforation following anterior cervical fusion is rare. Early development of an esophageal perforation after anterior cervical fusion is usually due to iatrogenic injury from retraction, injury associated with the original traumatic incident, improperly placed instruments or a bone graft. A 31-year-old man had a cervical dislocation and spinal cord injury because of severe cervical trauma after a traffic accident. He was quadriplegic and had no feeling below T4 dermatome. Anterior decompression of the cervical spine and anterior fusion with mesh with autobone were performed. An esophagocutaneous fistula occurred 7 days after anterior cervical surgery. A second anterior surgery was done because of pus drainage. The mesh was changed with an iliac bone graft, and the esophagocutaneous fistula site was primary repaired, but pus continued to drain. Conservative treatment, which consisted of wound drainage and intravenous administration of antibiotics, was tried, but was unsuccessful. After all, we removed the plate and screws, but did not removed the iliac bone graft, We closed the esophageal fistula, and transposed the sternocleidomastoid muscle flap to the interspace between the esophagus and the cervical spine. The wound to the esophagus was well repaired. In conclusion, precautionary measures are needed to avoid the complication, and adequate treatment is necessary to resolve those complications when they occur.

• Journal of Korean Neurosurgical Society
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• v.46 no.4
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• pp.328-332
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• 2009

Objective : The purpose of this study was to establish new fusion criteria to complement existing Brantigan-Steffee fusion criteria. The primary purpose of intervertebral cage placement is to create a proper biomechanical environment through successful fusion. The existence of a traction spur is an essential predictable radiologic factor which shows that there is instability of a fusion segment. We studied the relationship between the existence of a traction spur and fusion after a posterior lumbar interbody fusion (PLIF) procedure. Methods : This study was conducted using retrospective radiological findings from patients who underwent a PLIF procedure with the use of a cage without posterior fixation between 1993 and 1997 at a single institution. We enrolled 183 patients who were followed for a minimum of five years after the procedure, and used the Brantigan-Steffee classification to confirm the fusion. These criteria include a denser and more mature bone fusion area than originally achieved during surgery, no interspace between the cage and the vertebral body, and mature bony trabeculae bridging the fusion area. We also confirmed the existence of traction spurs on fusion segments and non-fusion segments. Results : The PLIF procedure was done on a total of 251 segments in 183 patients (71 men and 112 women). The average follow-up period was $80.4{\pm}12.7$ months. The mean age at the time of surgery was $48.3{\pm}11.3$ years (range, 25 to 84 years). Among the 251 segments, 213 segments (84.9%) were fused after five years. The remaining 38 segments (15.1%) were not fused. An analysis of the 38 segments that were not fused found traction spur formation in 20 of those segments (52.6%). No segments had traction spur formation with fusion. Conclusion : A new parameter should be added to the fusion criteria. These criteria should be referred to as 'no traction spur formation' and should be used to confirm fusion after a PLIF procedure.

• Journal of Korean Neurosurgical Society
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• v.59 no.6
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• pp.604-609
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• 2016

Objective : The aim of this study was to compare the clinical and radiological outcomes associated with the use of hydroxyapatite (HA) spacer and allogeneic bone (AB) spacer in laminoplasty. Methods : From January 2006 to July 2014, 79 patients with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament underwent cervical laminoplasty. The radiologic parameters were obtained from plain radiography and three-dimensional computed tomography. All images were taken before and after surgery. Cervical lordosis, spinal canal dimension, fusion between lamina and spacer, and resorption of spacer were checked. Clinical outcomes were assessed using visual analog scale and Japanese Orthopedic Association. Results : Double-door laminoplasty was performed on 280 levels : 182 in the HA group and 98 in the AB group. The mean follow-up was 23.1 months (range : 4-69 months). Similar fusion rates were found in these groups (p=0.3). The resorption rate between lamina and spacer was lower in the HA group (p<0.001). During the immediate postoperative period, the canal dimension of both groups increased compared with the results in the preoperative period. However, the canal dimension of the AB group decreased over time compared with that of the HA group (p<0.001). Conclusion : Double-door laminoplasty improved the clinical outcomes of both groups. However, the spinal canal dimension in the AB group showed a greater degree of reduction than in the HA group at the final postoperative follow-up. Therefore, we suggest that surgeons consider the use of larger-sized AB spacers in double-door laminoplasties.

• Journal of Korean Neurosurgical Society
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• v.30 no.5
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• pp.605-610
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• 2001

Objective : The authors investigated the efficacy of the calcium sulfate(OsteoSet$^{(R)}$ pellets) as an autograft extender when used to perform posterolateral lumbar fusions. Patients and Methods : Twenty patients who underwent lumbar posterolateral arthrodesis for various spinal diseases between October 1999 and March 2000 were evaluated. Arthrodesis was performed by transpedicular screw fixation and bone grafting with a mixture of autograft + calcium sulfate in a 1 : 1 ratio. At time intervals of 1, 2, 3, and 6 months, postoperative radiographs were obtained to review the resorption of calcium sulfate and the evidence of fusion. A modified Lenke scale was used to assess the status of the fusion. Results : At 2 months after operation, the average modified Lenke scale score for the OsteoSet$^{(R)}$ pellets group was 3.8. However at 6 months after operation, the average modified Lenke scale score for the OsteoSet$^{(R)}$ pellets group was 1.8. Resorption of calcium sulfate pellets was revealed in all cases at 6 months after surgery. Conclusion : It is presumed that a combination of calcium sulfate and autograft can play a role as an effective autograft extender in the posterolateral spinal fusion.

• Journal of Korean Neurosurgical Society
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• v.30 no.10
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• pp.1163-1169
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• 2001

Objective : To assess the surgical outcome for patients with primary spondylitis who were treated surgically. Materials and Methods : We retrospectively analyzed the clinical characteristics of 19 patients who underwent surgical treatment from september 1997 to October 1999 in our department. Results : The 19 patients presented 13 tuberculous spondylitis and 6 pyogenic spondylitis. The male to female ratio was 1.4 : 1 and average age 48.4 years(range 15-68 years). The most prevalent location was thoracic region(47%) and paraparesis was frequently seen in patients with middle and lower spinal lesions. Operative approaches were either anterior(13) or posterior(6). All patients with neurologic deficits improved after surgery. Autogenous rib and/or iliac strut bone grafting was performed, followed by spinal instrumentation. Solid bone fusion was obtained in all patients. There was no need for prolongation of duration of antituberculous drug therapy and no increased incidence of secondary infection due to spinal instrumentation. Conclusion : From the results, it may be advised that patients of primary spondylitis who had neurologic deficit should receive an aggressive opeation in their early stage.

• BMB Reports
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• v.44 no.10
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• pp.619-634
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• 2011

Bone morphogenetic protein (BMP) signaling in diseases is the subject of an overwhelming array of studies. BMPs are excellent targets for treatment of various clinical disorders. Several BMPs have already been shown to be clinically beneficial in the treatment of a variety of conditions, including BMP-2 and BMP-7 that have been approved for clinical application in nonunion bone fractures and spinal fusions. With the use of BMPs increasingly accepted in spinal fusion surgeries, other therapeutic approaches targeting BMP signaling are emerging beyond applications to skeletal disorders. These approaches can further utilize next-generation therapeutic tools such as engineered BMPs and ex vivo-conditioned cell therapies. In this review, we focused to provide insights into such clinical potentials of BMPs in metabolic and vascular diseases, and in cancer.