• Journal of Korean Neurosurgical Society
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• 제54권2호
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• pp.128-131
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• 2013

Transforaminal lumbar interbody fusion (TLIF) is commonly used procedure for spinal fusion. However, there are no reports describing anterior cage dislodgement after surgery. This report is a rare case of anterior dislodgement of fusion cage after TLIF for the treatment of isthmic spondylolisthesis with lumbosacral transitional vertebra (LSTV). A 51-year-old man underwent TLIF at L4-5 with posterior instrumentation for the treatment of grade 1 isthmic spondylolisthesis with LSTV. At 7 weeks postoperatively, imaging studies demonstrated that banana-shaped cage migrated anteriorly and anterolisthesis recurred at the index level with pseudoarthrosis. The cage was removed and exchanged by new cage through anterior approach, and screws were replaced with larger size ones and cement augmentation was added. At postoperative 2 days of revision surgery, computed tomography (CT) showed fracture on lateral pedicle and body wall of L5 vertebra. He underwent surgery again for paraspinal decompression at L4-5 and extension of instrumentation to S1 vertebra. His back and leg pains improved significantly after final revision surgery and symptom relief was maintained during follow-up period. At 6 months follow-up, CT images showed solid fusion at L4-5 level. Careful cage selection for TLIF must be done for treatment of spondylolisthesis accompanied with deformed LSTV, especially when reduction will be attempted. Banana-shaped cage should be positioned anteriorly, but anterior dislodgement of cage and reduction failure may occur in case of a highly unstable spine. Revision surgery for the treatment of an anteriorly dislodged cage may be effectively performed using an anterior approach.

• 대한의용생체공학회:의공학회지
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• 제25권6호
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• pp.525-530
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• 2004

Cage와 나사를 이용하여 유합된 추체의 3차원 유한 요소 모델을 제작하여, 골밀도의 변화에 따른 골다공증과 cage의 위치 변화에 대해, Von-Mites 최대 응력과 최대 변형량을 살펴보았다. 그 결과 해면골의 강도가 증가함에 따라서, 피질골의 응력은 감소하고, 해면골에서의 응력은 증가하였다. 또한 cage의 위치의 변화에 따라서 추체의 응력 분포의 양상이 달라짐을 알 수 있었으며, 이를 통해 수술의 성공도를 높이고자 한다.

• Journal of Korean Neurosurgical Society
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• 제38권4호
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• pp.255-258
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• 2005

Objective : Lumbar lordotic curve on L4 to S1 level is important in maintaining spinal sagittal alignment. Although there has been no definite report in lordotic value, loss of lumbar lordotic curve may lead to pathologic change especially in degenerative lumbar disease. This study examines the changes of lumbar lordotic curve after posterior lumbar interbody fusion with wedge shape cage. Methods : We studied 45patients who had undergone posterior lumbar interbody fusion with wedge shape cage and screw fixation due to degenerative lumbar disease. Preoperative and postoperative lateral radiographs were taken and one independent observer measured the change of lordotic curve and height of intervertebral space where cages were placed. Segmental lordotic curve angle was measured by Cobb method. Height of intervertebral space was measured by averaging the sum of anterior, posterior, and midpoint interbody distance. Clinical outcome was assessed on Prolo scale at 1month of postoperative period. Results : Nineteen paired wedge shape cages were placed on L4-5 level and 6 paired same cages were inserted on L5-S1 level. Among them, 18patients showed increased segmental lordotic curve angle. Mean increased segmental lordotic curve angle after placing the wedge shape cages was $1.96^{\circ}$. Mean increased disc height was 3.21mm. No cases showed retropulsion of cage. The clinical success rate on Prolo's scale was 92.0%. Conclusion : Posterior lumbar interbody fusion with wedge shape cage provides increased lordotic curve, increased height of intervertebral space, and satisfactory clinical outcome in a short-term period.

• Journal of Korean Neurosurgical Society
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• 제37권5호
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• pp.389-391
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• 2005

We report a case of T4 bursting fracture with paraparesis that recovered by posterior approach. A 47-year-old man presented with paraparesis (grade III) which had progressed rapidly after motor cycle accident. After sacrificing the T4 nerve root (right), posterior interbody fusion using cage following T4 corpectomy and T3-4, T4-5 discectomy was performed. After operation, lower extremities motor power improved and he could walk after one month. And this is the first report of posterior approach using cage by corpectomy and two level discectomy in case of upper thoracic burst fracture in Korea.

• Journal of Korean Neurosurgical Society
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• 제41권2호
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• pp.105-110
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• 2007

Objective : This purpose of this study was to determine the clinical efficiency and applicability, and to analyze the radiologic findings of the anterior cervical approach using two synthetic cages for interbody fusion. Methods : A total of 41 patients with cervical diseases underwent anterior discectomy and interbody fusion with the PEEK $Solis^{TM}$ cage in 21 patients and the carbon composite $Osta-Pek^{TM}$ cage in 20 patients. Outcome assessment was done using Odom's criteria. Radiological assessment was performed with respect to subsidence, bony fusion and lordosis. The mean follow-up period was 13 months. Results : There were 34 [92.9%] successful cases. The average height of the disc space 12 months after surgery compared the height just after surgery was decreased over 3mm in 4 cases, indicating severe subsidence. The use of these synthetic cages have provided the increase in postoperative cervical lordosis. Conclusion : There were no significant differences between the $Solis^{TM}$ and $Osta-Pek^{TM}$ cages on clinical and radiologic outcomes. Both $Solis^{TM}$ and $Osta-Pek^{TM}$ cages showed low subsidences and complications associated with hardware with good clinical outcomes, high fusion rates, restored disc heights, and restored cervical lordosis.

• Journal of Korean Neurosurgical Society
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• 제41권5호
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• pp.301-305
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• 2007

Objective : The postoperative subsidence of anterior cervical interbody fusion for cervical degenerative diseases gives rise to segmental kyphotic collapse, screw loosening, and chronic neck pain. So, intraoperative custom-made polymethylmethacrylate [PMMA] C-cage has been developed to prevent subsidence following anterior cervical fusion. Methods : A total of patients who underwent anterior cervical interbody fusion with a intraoperative custom - made cervical cage filled with local bone and demineralized bone matrix [group A] were analyzed prospectively from June 2004 to June 2005. These were compared with 40 patients who were treated with iliac bone graft [group B]. We evaluated subsidence ratio, change of segmental angle, distraction length and segmental angle. Statistical analysis was performed using independent sample t-test and Pearson correlation coefficient. Results : Group A had a statistically significant decrease in subsidence ratio [$0.64{\pm}0.43%$, p=0.00]. distraction length [$2.42{\pm}1.25\;mm$, p=0.02], and follow angle change [$1.78{\pm}1.69^{\circ}$, p=0.01] as compared with Group B. However, there was no statistically significant difference in postoperative segmental angle change [p=0.66]. On the analysis of the correlation coefficient, the parameters showed no interrelationships in the group A. On the other hand, subsidence ratio was affected by distraction length in the group B [Pearson correlation=0.448]. Conclusion : This operative technique would be contributed for the reduction of a postoperative subsidence after the anterior cervical interbody fusion procedure for cervical disc disease with moderate to severe osteoporotic condition and segmental loss of lordosis.

• Journal of Korean Neurosurgical Society
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• 제48권3호
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• pp.219-224
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• 2010

Objective : A minimally invasive transforaminal lumbar interbody fusion (MIS TLlF) has recently been introduced. However, MIS TLlF is a technically challenging procedure. The authors performed retrospective analysis about MIS TLlF using a single interbody cage. Methods : Twenty-eight consecutive patients were treated by MIS TLlF. Of these 28 patients, 20 patients were included in this retrospective study. Perioperative, clinical, and radiologic outcomes were assessed. Clinical outcomes were assessed using Oswestry Disability Index (ODI) and Visual Analogue Scores (VAS). Fusion rates and cross-sections of operated spinal canals were assessed by CT. Results : Twelve patients underwent MIS TLlF at one segment and 8 patients at two segments (L3/4: 4, L4/5: 17, L5/S1: 7). Operation time for a single segment was 131.7 min and for two segment was 201.4 min, and corresponding blood losses were 208.3 mL and 481.2 mL, respectively. ODI and VAS scores were significantly improved at 6 months postop (ODI from 30.32 to 15.54, VAS from 7.80 to 2.20, p = 0.001) Twenty-two segments (78.6%) achieved grade I fusion, 4 segments (14.3%) achieved grade II, 2 segments (7.1%) achieved grade III and 0 segments achieved grade IV at 12 months. Postoperatively at 12 months, spinal canal cross sectional areas at disc spaces significantly increased from 157.5 to $294.3\;mm^2$ (p = 0.012). Conclusion : MIS TLlF achieved good clinical outcomes and high fusion rates. Our findings show that MIS TLlF performed with a single Interbody cage and a tubular retractor system can be used as a standard MIS TLlF technique.

• Journal of Korean Neurosurgical Society
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• 제39권4호
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• pp.260-264
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• 2006

Objective : The retrospective study is undertaken to report clinical results of anterior cervical interbody fusion with an intradiscal cage with an integrated plate [PCB cervical plating system]. Methods : 38 patients underwent anterior cervical interbody fusion with PCB cervical plating system and followed $6{\sim}24\;months$. The authors investigated overall surgical results; clinical outcome, fusion rate, change of interspace height & lordotic angle, and complications. Results : No complication was observed during the operation. Clinical improvement was identified in 34 cases [89.5%]. Bone fusion observed in 44 out of 49 sites [90.7%]. After operation, the interspace height increased from $5.4{\pm}1.3mm$ to $7.8{\pm}1.5mm$ and maintained $7.4{\pm}1.1mm$ and, interspace angle went up from $4.2{\pm}0.7^{\circ}$ to $4.8{\pm}1.1^{\circ}$ and maintained $4.6{\pm}$0.9^{\circ}. The loosening of screw was observed in 6 cases, one of which had reoperation because of the expulsion of the device accompanied. Conclusion : PCB cervical plating system could restore interbody height and lordosis in anterior cervical interbody fusion. But, if the insertion of the spacer is not precise, the frequencies of hardware failure are relatively high. It is considered necessary for the operator to be careful in the procedure.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.1364-1367
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• 2003

These days, spinal interbody arthrodesis using fusion cage is very popular. The cage used for the spinal interbody arthrodesis is mainly inserted from the posterior of the spine. Accordingly, there could possibly occur damages at posterior and results in instability of structure. Moreover, one or two cages are inserted depending on the patients. In this study, it is attempted to evaluate the stability quantitatively by comparing two cases where one and two cages are inserted. For this purpose, a very fine 3-dimensional finite element model of vertebra is generated from the MRI data. From this vertebra model, two models are made: one with one cage and the other with two cages. Finally, finite element analys is performed for these two models and both of the mechanical behaviors are examined In addition, the effect on the stability is evaluated and compared quantitatively.

• Journal of Korean Neurosurgical Society
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• 제46권4호
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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.