• Journal of Korean Foot and Ankle Society
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• v.8 no.1
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• pp.31-38
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• 2004

Purpose: The purpose of the study was to identify the subtypes of idiopathic osteoarthritis of the tarsometatarsal joints based on accompanying hindfoot, midfoot, or foot deformities and their corresponding surgical options and also to evaluate the overall clinical results. Materials and Methods: The study included 59 patients (67 feet) with idiopathic tarsometatarsal joint osteoarthritis. Tarsometatarsal fusion was performed for tarsometatarsal joint and accompanied secondary change was divided into subtypes and various bony reconstruction was carried out. The patients were evaluated with the AOFAS midfoot score and FFI. The average patient age was 60.2 years with 40.6 months follow-up. Fifty-four feet (80.6%) had been treated with realignment fusion. Twenty-six feet had first and second tarsometatarsal joint fusion, and 20 feet had first tarsometatarsal fusion only. Six subtypes were identified based on associated foot deformities: 1) in-situ without deformities (18%), 2) pes planovalgus (45%), 3) rockerbottom (15%), 4) cavus foot (1%), 5) hallux valgus (12%), and 6) hallux valgus with pes planovalgus or rockerbottom (9%). Plantar-medial closing-wedge resection was used in 10 feet to correct rockerbottom. For pes planovalgus, a medial sliding calcaneal osteotomy was done. Lateral column lengthening with medial sliding calcaneal osteotomy was done for severe pes planovalgus, and triple arthrodesis was done for rigid pes planovalgus. Hallux valgus was corrected with the Lapidus procedure (85.7%). Results: AOFAS midfoot scores improved from preoperative 34.1 points to postoperative 83.9 points (p<0.05). The Foot Function Index postoperatively also showed significant improvement (p<0.05), with a high satisfaction rate (86.6%). There were 29 complications, most commonly sesamoid pain. Conclusion: Idiopathic tarsometatarsal OA feet can be classified into six categories. Pes planovalgus feet should be treated with medial sliding calcaneal osteotomy, lateral column lengthening, or triple arthrodesis in addition to tarsometatarsal joint realignment fusion. Rockerbottom and hallux valgus deformities should also be addressed.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.248-254
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• 2014

Objective : According to the recent development of minimally invasive spinal surgery, direct lumbar interbody fusion (DLIF) was introduced as an effective option to treat lumbar degenerative diseases. However, comprehensive results of DLIF have not been reported in Korea yet. The object of this study is to summarize radiological and clinical outcomes of our DLIF experience. Methods : We performed DLIF for 130 patients from May 2011 to June 2013. Among them, 90 patients, who could be followed up for more than 6 months, were analyzed retrospectively. Clinical outcomes were compared using visual analog scale (VAS) score and Oswestry Disability Index (ODI). Bilateral foramen areas, disc height, segmental coronal and sagittal angle, and regional sagittal angle were measured. Additionally, fusion rate was assessed. Results : A total of 90 patients, 116 levels, were underwent DLIF. The VAS and ODI improved statistically significant after surgery. All the approaches for DLIF were done on the left side. The left and right side foramen area changed from $99.5mm^2$ and $102.9mm^2$ to $159.2mm^2$ and $151.2mm^2$ postoperatively (p<0.001). Pre- and postoperative segmental coronal and sagittal angles changed statistically significant from $4.1^{\circ}$ and $9.9^{\circ}$ to $1.1^{\circ}$ and $11.1^{\circ}$. Fusion rates of 6 and 12 months were 60.9% and 87.8%. Complications occurred in 17 patients (18.9%). However, most of the complications were resolved within 2 months. Conclusion : DLIF is not only effective for indirect decompression and deformity correction but also shows satisfactory mechanical stability and fusion rate.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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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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• v.53 no.1
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• pp.19-25
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• 2013

Objective : We compared the results of two surgical techniques by retrospective study of 60 elderly patients (65 years or older) who underwent either decompression alone or fusion for the treatment of two-level or more lumbar spinal stenosis. Methods : During the period of 2003 and 2008, two-level or more decompression alone or fusion was performed for lumbar spinal stenosis by three surgeons at our institution. Patients were allocated to two groups by surgical modality, namely, to a decompression group (31 patients) or a fusion group (29 patients). Overall mean age was 71.1 years (range, 65-84) and mean follow-up was 5.5 years (range, 3-9). A retrospective review of clinical, radiological, and surgical data was conducted. Results : No significant difference between the two groups was found with respect to age, follow-up period, surgical levels, or preoperative condition. At the last follow-up, correction of lumbar lordotic angle (determined radiologically) was better in the fusion group. However, clinical outcomes including visual analogue scale, Oswestry Disability Index, and the Odom's criteria were not significantly different in the two groups. On the other hand, surgical outcomes, such as, operation time, estimated blood loss, and surgical complications were significantly better in the decompression alone group. Conclusion : Our findings suggest that decompressive laminectomy alone achieves good outcomes in patients with two-level or more lumbar spinal stenosis, associated with an advanced age, poor general condition, or osteoporosis.

• Journal of Korean Neurosurgical Society
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• v.50 no.4
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• pp.363-369
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• 2011

Objective : We investigated the clinical and radiological advantages of unilateral laminectomy in posterior lumbar interbody fusion (PLIF) procedure comparing with bilateral laminectomy, under the same procedural condition including bilateral instrumentation and insertion of two cages, in patients with degenerative lumbar disease with unilateral leg symptoms. Methods : We retrospectively reviewed 124 consecutive cases of PLIF via unilateral or bilateral approach between January 2006 and April 2010. In 80 cases (bilateral group), two cages were inserted via bilateral laminectomy, and in 44 cases (unilateral group), via unilateral laminectomy. The average follow-up duration was 29.5 months. The clinical outcomes were evaluated with the Visual Analogue Scale (VAS) and the Oswestry disability index (ODI). The fusion rates and disc space heights were determined by dynamic standing radiographs and/or computed tomography. Operative times, intra-operative and post-operative blood losses and hospitalization periods were also evaluated. Results : In clinical evaluation, the VAS and ODI scores showed excellent outcomes in both groups. There were no significant differences in term of fusion rate, but the perioperative blood loss and the operative time of the unilateral group were lower than that of the bilateral group. Conclusion : Unilateral laminectomy can minimize the operative time and perioperative blood loss in PLIF procedure. However, the different preoperative disc height between two groups is a limitation of this study. Despite this limitation, solid fusion and satisfactory symptomatic improvement could be achieved uniquely by our surgical method. This surgical method can be an alternative surgical technique in patients with unilateral leg pain.

• Composites Research
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• v.16 no.2
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• pp.26-32
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• 2003

Optical fibers, for splice, are stripped of their plastic coatings with a plastic stripper and cut off at the end. Therefore, stripped fibers often receive accidental damages and sustain small flaws or cracks. As a result, the breaking strength of a fiber splice made under normal conditions is reduced to about 0.4∼1 ㎏ on the average, nearly one-tenth of the fiber's strength. This makes it necessary to reinforce the splice. One of the most practical and reliable methods for optical fiber splicing is fusion splicing, comprising the steps of tripping the plastic coatings from the two fiber ends to be splice, placing the two bare fiber ends in an end-to-end position, and of fusion splicing, such as are fusion. Generally, steel bar (SB) sleeve is used to reinforce this fusion-splicing region. However, this type of sleeve has a critical defect to keep optical lose after bent by a sudden load. New type of composite spring (CS) sleeve is developed to make up for the weak points in the SB sleeve. This sleeve has an effect on restoration to the original state after eliminating the bending load. The optical spectrum analyzes results show the availability of reinforcement for the fusion splicing optical fiber using small diameter composite springs under the various loading conditions.

• Journal of Korean Neurosurgical Society
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• v.62 no.1
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• pp.83-89
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• 2019

Objective : This study is a retrospective cost-benefit analysis of cervical anterior interbody fusion and cervical artificial disc replacement, which are the main surgical methods to treat degenerative cervical disc disease. Methods : We analyzed 156 patients who underwent anterior cervical disc fusion and cervical artificial disc replacement from January 1, 2008 to December 31, 2009, diagnosed with degenerative cervical disc disorder. In this study, the costs and benefits were analyzed by using quality adjusted life year (QALY) as the outcome index for patients undergoing surgery, and a Markov model was used for the analysis. Only direct medical costs were included in the analysis; indirect medical costs were excluded. Data were analyzed with TreeAge Pro $2015^{TM}$ (TreeAge Software, Inc, Williamstown, MA, USA). Results : Patients who underwent cervical anterior fusion had a total cost of KRW 2501807/USD 2357 over 5 years and obtained a utility of 3.72 QALY. Patients who underwent cervical artificial disc replacement received 4.18 QALY for a total of KRW 3685949/USD 3473 over 5 years. The cumulative cost-effectiveness ratio of cervical spine replacement surgery was KRW 2549511/QALY (USD 2402/QALY), which was lower than the general Korean payment standard. Conclusion : Both cervical anterior fusion and cervical artificial disc replacement are cost-effective treatments for patients with degenerative cervical disc disease. Cervical artificial disc replacement may be an effective alternative to obtain more benefits.

• Journal of Korean Neurosurgical Society
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• v.64 no.4
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• pp.552-561
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• 2021

Objective : To compare the anterior cervical discectomy and fusion (ACDF) and posterior cervical fusion (PCF) with wide facetectomy in the treatment of parallel-shaped bony foraminal stenosis (FS). Methods : Thirty-six patients underwent surgery due to one-or-two levels of parallel-shaped cervical FS. ACDF was performed in 16 patients, and PCF using CPS was performed in 20 patients. All patients were followed up at 1, 3, 6, and 12 months postoperatively. Standardized outcome measures such as Numeric rating scale (NRS) score for arm/neck pain and Neck disability index (NDI) were evaluated. Cervical radiographs were used to compare the C2-7 Cobb's angle, segmental angle, and fusion rates. Results : There was an improvement in NRS scores after both approaches for radicular arm pain (mean change -6.78 vs. -8.14, p=0.012), neck pain (mean change -1.67 vs. -4.36, p=0.038), and NDI score (-19.69 vs. -18.15, p=0.794). The segmental angle improvement was greater in the ACDF group than in the posterior group (9.4°±2.7° vs. 3.3°±5.1°, p=0.004). However, there was no significant difference in C2-7 Cobb angle between groups (16.2°±7.9° vs. 14.8°±8.5°, p=0.142). As a complication, dysphagia was observed in one case of the ACDF group. Conclusion : In the treatment of parallel-shaped bony FS up to two surgical levels, segmental angle improvement was more favorable in patients who underwent ACDF. However, PCF with wide facetectomy using CPS should be considered as an alternative treatment option in cases where the anterior approach is burdensome.

• 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.

• Macromolecular Research
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• v.10 no.3
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• pp.168-173
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• 2002

Unstabilized low-density polyethylene (LDPE) films and films formulated with hindered amine light stabilizer (HALS) were exposed to UV-radiation; and the physicochemical changes during photooxidation processes have been investigated using tensile, FTIR spectre-photometric and thermal analytical (DSC) techniques. The dependence of tensile properties (elongation- and stress-at-break), carboxyl index and heat of fusion on UV-irradiation time have been discussed. The use of HALS is found to be effective in maintaining the UV-mechanical properties of the LDPE films. The experimental results showed that there exists no correlation between mechanical properties and carbonyl index, whereas crystallinity correlates well with carbonyl index in unstabilized and stabilized films for irradiation times greater than 100 h. The rate of formation of carbonyl groups is found to be dependent on UV exposure time. Crystallinity of the film samples is strongly influenced by both exposure time and presence of HALS.