Video-Assisted Thoracoscopic Surgery for Correction of Adolescent Idiopatic Scoliosis: Comparison of 4.5 mm versus 5.5 mm Rod Constructs

PURPOSE: The purpose of this study is to report the comparative results of thoracoscopic correction achieved via cantilever technique using a 4.5 mm thin rod and the poly-axial reduction screw technique using a 5.5 mm thick rod in Lenke type 1 adolescent idiopathic scoliosis (AIS). MATERIALS AND METHODS: Radiographic data, Scoliosis Research Society (SRS) patient-based outcome questionnaires, and operative records were reviewed for forty-nine patients undergoing surgical treatment of scoliosis. The study group was divided into a 4.5 mm thin rod group (n = 24) and a 5.5 mm thick rod group (n = 25). The radiographic parameters that were analyzed included coronal curve correction, the most caudal instrumented vertebra tilt angle correction, coronal balance, and thoracic kyphosis. RESULTS: The major curve was corrected from 49.8degrees and 47.2degrees pre-operatively to 24.5degrees and 18.8degrees at the final follow-up for the thin and thick rod groups, respectively (50.8% vs. 60.2% correction). There were no significant differences between the two groups in terms of kyphosis, coronal balance, or tilt angle at the time of the final follow-up. The mean number of levels fused was 6.2 in the thin rod group, compared with 5.9 levels in the thick rod group. There were no major intraoperative complications in either group. CONCLUSION: Significant correction loss was observed in the thin rod system at the final follow-up though both groups had comparable correction immediately post-operative. Therefore, the thick rod with poly axial screw system helps to maintain post-operative correction.

Incidence and Risk Factors Associated with Superior Mesenteric Artery Syndrome following Surgical Correction of Scoliosis

STUDY DESIGN: Retrospective study. PURPOSE: To more accurately determine the incidence and clarify risk factors. OVERVIEW OF LITERATURE: Superior mesenteric artery syndrome is one of the possible complications following correctional operation for scoliosis. However, when preliminary symptoms are vague, the diagnosis of superior mesenteric artery syndrome may be easily missed. METHODS: We conducted a retrospective study using clinical data from 118 patients (43 men and 75 women) who underwent correctional operations for scoliosis between September 2001 and August 2007. The mean patient age was 15.9 years (range 9~24 years). The risk factors under scrutiny were the patient body mass index (BMI), change in Cobb's angle, and trunk length. RESULTS: The incidence of subjects confirmed to have obstruction was 2.5%. However, the rate increased to 7.6% with the inclusion of the 6 subjects who only showed clinical symptoms of obstruction without confirmative study. The BMI for the asymptomatic and symptomatic groups were 18.4+/-3.4 and 14.6+/-3, respectively. The change in Cobb's angle for the asymptomatic and symptomatic groups were 24.8+/-13.6degrees and 23.4+/-9.1degrees, respectively. The change in trunk length for the asymptomatic and symptomatic groups were 2.3+/-2.1 cm and 4.5+/-4.8 cm, respectively. Differences in Cobb's angle and the change in trunk length between the two groups did not reach statistical significance, although there was a greater increase in trunk length for the symptomatic group than for the asymptomatic group. CONCLUSIONS: Our study shows that the incidence of superior mesenteric artery syndrome may be greater than the previously accepted rate of 4.7%. Therefore, in the face of any early signs or symptoms of superior mesenteric artery syndrome, prompt recognition and treatment are necessary.

Polyaxial Screws with Thick Rod versus Monoaxial Screws with Thin Rod in Video-Assisted Thoracoscopic Scoliosis Surgery (VATS) / 대한척추외과학회지

STUDY DESIGN: Prospective controlled cohort study OBJECTIVE: To analyze the clinical outcome of video-assisted thoracoscopic surgery (VATS) between two different types of implants. SUMMARY OF LITERATURE REVIEW: The problem of correction loss has been reported with VATS, and different screws and rods have been developed to overcome this problem. Different implants will have varying effects in correctional outcome after VATS. MATERIALS AND METHODS: A total of 39 cases of idiopathic adolescent scoliosis treated with VATS between June 2001 and January 2005 were included in the study (mono-axial screws and a 4.5 mm rod: thin rod group=19 cases; poly-axial reduction screws and a 5.5 mm diameter rod: thick rod group=20 cases). All patients were followed for over 2 years postoperatively. For the comparison of surgical outcomes between the two groups, radiographic measurements were performed in the coronal and sagittal planes. RESULTS: Preoperative scoliosis angle (thin rod group 49.8degrees, thick rod group 47.1degrees), age, BMI, Risser stage, union time, operative time, and blood loss showed no statistical difference between the two groups. Postoperative average correction rate of scoliosis angle was 69% (15.8degrees) in the thin rod group and 70% (14.1degrees) in the thick rod group. However, correction rate after 2 years was 51% (24.5degrees) in the thin rod group and 60% (18.7degrees) in the thick rod group, showing statistically significant difference. There was a tendency toward correction loss in the thin rod group (8.7degrees vs. 4.6degrees p=0.0057). CONCLUSION: Postoperative correction rate was satisfactory in both groups. However, the thin rod group showed substantial correction loss. Therefore, poly-axial screws and thick rods are more suitable in VATS correction of scoliosis.

The Incidence of New Vertebral Compression Fractures in Women after Kyphoplasty and Factors Involved

PURPOSE: To identify the incidence of new vertebral compression fractures in women after kyphoplasty and to analyze influential factors in these patients. MATERIALS AMD METHODS: One hundred and eleven consecutive female patients with osteoporotic vertebral compression fractures (VCFs) underwent kyphoplasty at 137 levels. These patients were followed for 15.2 months postoperatively. For the survey of new vertebral compression fractures, medical records and x-rays were reviewed, and telephone interviews were conducted with all patients. RESULTS: During that time 20 (18%) patients developed new VCFs. The rate of occurrence of new VCFs in one year was 15.5% using a Kaplan-Meier curve. Body mass index (BMI), symptom duration and kyphoplasty level were the statistically significant factors between the patient groups both with and without new VCFs after kyphoplasty. In the comparison between the adjacent and remote new VCF groups, the adjacent new VCF group showed a larger amount of polymethyl methacrylate (PMMA) use during kyphoplasty (p<0.05). Before kyphoplasty, 9.9% of the patients had been prescribed medication for osteoporosis, and 93.7% of the patients started or continued medication after kyphoplasty. The development of new VCFs was affected by the number of vertebrae involved in the kyphoplasty. However, the lower incidence rate (15.5%) of new compression fractures might be due to a greater percentage (93.7% in our study) of patients taking anti-osteoporotic medication before and/or after kyphoplasty. CONCLUSION: When kyphoplasty is planned for the management of patients with osteoporotic VCFs, the application of a small amount of PMMA can be considered in order to lower the risk of new fractures in adjacent vertebrae. The postoperative use of anti- osteoporotic medication is recommended for the prevention of new VCFs.

Delayed Onset Neurological Deterioration due to a Spinal Epidural Hematoma after a Spine Fracture

There are no reports of a 7-day delay in the onset of neurological deterioration because of a spinal epidural hematoma (SEH) after a spinal fracture. A hematoma was detected from the T12 to L2 area in a 36-year-old male patient with a T12 burst fracture. On the same day, the patient underwent in situ posterior pedicle instrumentation on T10-L3 with no additional laminectomy. On the seventh postoperative day, the patient suddenly developed weakness and sensory changes in both extremities, together with a sharp pain. A MRI showed that the hematoma had definitely increased in size. A partial laminectomy was performed 12 hours after the onset of symptoms. Two days after surgery, recovery of neurological function was noted. This case shows that spinal surgeons need to be aware of the possible occurrence of a delayed aggravated SEH and neurological deterioration after a spinal fracture.

A Comparison of Bone Mineral Density between Adolescent Idiopathic Scoliosis and Neuromuscular Scoliosis / 대한척추외과학회지

STUDY DESIGN: A Cross-sectional study OBJECTIVE: This study evaluated the degree of osteoporosis of adolescent idiopathic scoliosis (AIS) and neuromuscular scoliosis (NMS) and compared bone mineral density. LITERATURE REVIEW: In osteoporosis, bone mineral density was not as dense even in the outer layer, and the cortex was thinner than normal. A larger screw doss not enhance the screw stability and can break the thin cortex in osteoporotic vertebrae. MATERIALS AND METHODS: This study reviewed the cases of consecutive patients with scoliosis, who underwent an osteoporosis examination before surgery between August 2004 and June 2006. The osteoporosis examination included DEXA in lumbar vertebrae and proximal femur. The mean osteoporotic degree of both femurs was recorded. The data was analyzed using the BMD(bone mineral density, g/cm(2)) and Z value of the BMD according to age, gender, and ethnicity. RESULTS: The mean degree of the coronal deformity was 48.4 in AIS and 62.9 in NMS. A comparison of both groups revealed a significantly lower BMD and Z value of Femur, and BMD of the vertebra in the NMS patients (p<0.05). A comparison between AIS and non-ambulant NMS showed that all parameters were significantly lower in the non-ambulant NMS (p<0.05). Neither the BMD and Z value of the AIS nor the NMS were associated with the severity of the spinal deformity. CONCLUSION: A lower BMD was measured in patients with non ambulant NMS than AIS. The degree of the osteoporosis, particularly of the non ambulant NMS patients need to be considered before undergoing surgery.

A Change of Pulmonary Function in the Patients with Severe Non-Idiopathic Scoliosis Following Reconstructive Spine Surgery / 대한척추외과학회지

STUDY DESIGN: This is a retrospective study OBJECTIVES: We wanted to investigate the changes in pulmonary function after spine surgery for the patients suffering with severe non-idiopathic scoliosis. SUMMARY OF LITERATURE REVIEW: The potential for pulmonary function change after scoliosis surgery may be much greater for the patients with neuromuscular, congenital or neuro-fibromatosis because of the severe thoracic deformity. Yet few studies have been performed on this subject. MATERIALS AND METHODS: 12 non-idiopathic scoliosis patients (average age: 11.1 years) were followed up for more than one year. Among these patients, 7 had muscular dystrophy, 3 had spinal muscular atrophy, 1 had Guillain-BarreSyndrome and 1 had neuro-fibromatosis. Surgery was done through the anterior and posterior approaches in 7 cases, and the posterior approach was used in 5 cases. In the former group, open thoracotomy was performed in 6 cases. NIPPV (non-invasive positive pressure ventilation) was used for 4 patients before surgery. RESULTS: The average Cobb's angle improved from preoperative 93.9 to postoperative 42.4, showing 55% correction. The average FVC was 1270ml before surgery and 1365 ml postoperatively, and the average FEV1 was 1163 ml preoperatively and 1300 ml postoperatively, showing a slightly increased FEV1. When these data were analyzed in detail, the FVC was decreased from preoperative 72.3% to 63.8% postoperatively in the 6 patients who underwent open thoracotomy. On the other hand, it was increased from preoperative 43% to 47.5% postoperatively in the 6 patients who did not undergo thoracotomy. CONCLUSION: Although the pulmonary function deteriorated after reconstructive spine surgery in some patients, worsening was seen mainly in those patients who underwent thoracotomy. The pulmonary function was actually improved in the patients who underwent surgery without thoracotomy to correct their severe scoliosis

Hibernoma in Psoas Muscle: A Case Report / 대한척추외과학회지

Hibernoma is a rare benign tumor of a brown fat origin with hypervascularity. Although the magnetic resonance imaging features resemble a liposarcoma, its malignant potential is unknown. A complete local excision with meticulous hemostasis is the treatment of choice. We present a case of hibernoma in the psoas muscle with a review of the relevant literature.

Comparison of the Predictive Value of Myelography, Computed Tomography and MRI on the Treadmill Test in Lumbar Spinal Stenosis

To date, there have been no prospective, objective studies comparing the accuracy of the MRI, myelo-CT and myelography. The purpose of this study is to compare the diagnostic and predictive values of MRIs, myelo-CTs, and myelographies. Myelographies with dynamic motion views, myelo-CTs, MRIs and exercise treadmill tests were performed in 35 cases. The narrowest AP diameter of the dural sac was measured by myelography. At the pathologic level, dural cross-sectional area (D-CSA) was calculated in the MRI and Myelo-CT. The time to the first symptoms (TAF) and the total ambulation time (TAT) were measured during the exercise treadmill test and used as the standard in the comparison of correlation between radiographic parameters and walking capacity. The mean D-CSA by CT was 58.3 mm2 and 47.6 mm2 by MRI. All radiographic parameters such as AP diameters and D-CSA have no correlation to TAF or TAT (p > 0.05). Our data showed no statistically significant differences in the correlation of the patients' walking capacity to the severity of stenosis as assessed by myelography, myelo-CT and MRI.

Operative Treatment for Proximal Phalangeal Neck Fractures of the Finger in Children

Displacement and inappropriate treatment of a proximal phalangeal neck fracture may result in malunion of the fracture with consequent loss of motion and gross deformity, especially in children. We performed a retrospective study of twenty-four patients who had undergone operative treatment for a proximal phalangeal neck fracture, with a mean follow-up evaluation of 14 months (range: 12-30 months). We analyzed the types of fractures, their causes, operative treatments, complications, and functional outcomes. The age of the patients ranged from 2 to 14 years (average: 4.8 years). Twenty of the 24 patients had open reduction and internal fixation, and fourteen of these 20 patients had criss-cross pin fixation. Four of the 24 patients had closed reduction and percutaneous pinning. The average length of immobilization was 3.5 weeks. Excellent or good results were seen in 18 patients (75%). Two patients had complications, which included volar angular deformity and mild button-hole deformity. We recommend that careful initial radiography, particularly, true lateral view radiographs, be required for proper diagnosis. The best results can only be obtained with accurate anatomical reduction of the fracture and early active motion exercise.

Learning Curve for the Thoracoscopic Correction of Spinal Deformities / 대한척추외과학회지

STUDY DESIGN: Twenty-six consecutive cases were prospectively studied by chart review and radiography. OBJECTIVES: The aim of this study was to find the learning curve of spinal thoracoscopy in spinal deformity surgery. SUMMARY OF LITERATURE REVIEW : Although the efficacy and learning curve of thoracoscopic deformity spinal surgery are well documented in many countries, there is no report in Korea. METHODS: Twenty-six consecutive patients who were underwent VATS were studied. Idiopathic scoliosis was diagnosed in 23 patients (King type II in 15, type III in 5, type IV in 3), neuromuscular scoliosis in 2 and kyphotic deformity in one. In 14 cases of idiopathic scoliosis VATS for anterior release, bonegraft and instrumentation were performed. In the remaining 12 cases of anterior release, bone graft by VATS was done without instrumentation. RESULTS: The average number of discs excised was 5.2+/-0.97. The average time of surgery for the 14 cases was 7.3+/-1.3 hours, which represented 1.37+/-0.25 hours per disc. Excluding the time of instrumentation in the 26 cases, the average time for anterior release and bone grafting was 3.87+/-0.87 hours, which represented 0.76+/-0.18 hours per disc. The average operation time diminished as the series continued. Average blood loss was 748.9+/-254 mL, which represented 152.6+/-65.6 mL per disc. The Cobb's angle was corrected by 62% on average. Complications were found in 11 cases: screw cap breakage in 3, atelectasis in 4, and intercostal nerve injury in 4. There was no serious complication. CONCLUSIONS: VAST for spinal deformity is a safe and effective alternative to thoracotomy, however, the learning curve for this procedure is quite difficult.

Bone Forming Gene Therapy (Immune Animal Model in Ex Vivo Gene Therapy for Spinal Fusion with Type 5 Adenoviral Delivery of the LIM Mineralization Protein-1 cDNA) / 대한척추외과학회지

STUDY DESIGN: In vivo study to determine the immune effects to adenoviral vector encoding LMP-1 cDNA in rabbit. OBJECTIVE: To quantify the immune effect of Ad5-LMP-1 in the rabbit during the therapeutic gene transfer. SUMMARY OF LITERATURE REVIEW: One of the major limitations in the use of adenoviral vector for gene therapy is the immune response and it made the poor transduction efficiency when re-administrated. Adenoviral antigen plus those derived from transgene expression in transduced cell contribute to cellular, humoral and non-specific immune response constitutes barriers to successful gene therapy. Therefore, the animal immune model will be mandatory to study the immune impact. MATERIALS AND METHOD: We i.v. injected Ad5-betaGal to total 24adult NZW rabbits; 1x108, 1x109, 1x1010, 1x1011v.p. to each 6 rabbits allowed them to develop immune response. Six non-immunized animals were used as control. Adenovirus antibodies were measured at 0, 4, 8, 16, 20 weeks. Group I. 6 control rabbit underwent spinal arthrodesis at 4 weeks (n=3) and 16 weeks (n=3) with 4 million cells and MOI of 4. Group II. 6 rabbit underwent spinal arthrodesis at 4 weeks after injection of 108 p.f.u virus (n=3) and 16 weeks (n=3). Group III. six 109 immunized rabbits, Group IV. six 1010 immunized rabbits, Group V. six 1011 immunized rabbits, underwent spinal arthrodesis at 4 and 16 weeks after injection. Total anti-Ad Ig and neutralizing antibody titer was measured on the 0. 4. 8, 16, 20 weeks after injection. RESULTS: Group I. All 6 non-immunized rabbits had solid spine fusions at 4 and 16 weeks. Group II. All 3immunized rabbits had not spine fusions at 4 weeks and all three had solid spine fusion at 16 weeks. Group III. None of them (n=6) immunized rabbits had spine fusion at 4 and 16weeks, but some bone formation was observed at 16 weeks. Group IV, V. None of them immunized rabbits had bone formation. The anti-Ad5 Ig and neutralizing Ab were detected and peaked at the 4weeks and significantly dropped off 16 weeks after injection. CONCLUSION: This experiment revealed that a small dose of adenovirus elicited an enough immune response that inhibited the bone formation. Because majority of human posses the Ab against adenovirus, it will be mandatory to overcome immune response in adenoviral vector gene therapy.

Chondroblastoma in Hand: A Case Report / 대한정형외과학회잡지

A 25 year-old man complained of pain at the distal interphalangeal joint of the middle finger for 3 months. The radiographs revealed an unicondylar osteolytic lesion at the head of middle phalanx. Enchondroma was initially suspected and curettage was performed, and final diagnosis was chondroblastoma. The size of the lesion increased and multiple septation developed at 9 months follow up. Curettage and bone graft was performed. Radiologic improvement was observed at 1 year after operation. Chondroblastoma developing at the phalanx is first report in our country, and this report can serve as a reminder at the diagnosis of osteolytic lesion in hand.

Unilateral versus Bilateral Pedide Scrwe Fixation in Lumbar Spinal Fusion / 대한정형외과학회잡지

OBJECTIVES: To determine if unilateral pedicle screw fixation is comparable to bilateral fixation in one-or two-segment lumbar spinal fusion. METHODS: Eighty-eight patients with spinal stenosis or spondylolisthesis were assigned to either unilateral or bilateral pedicle screw instrumentation groups. Demographic variables, preoperative diagnosis, number of fusion segments, and kinds of instrumentation used were similar between the two treatment groups. RESULTS: There were no significant differences between the two groups in terms of blood loss, clinical results, time at which fusion was complete, fusion rate, and complication rate. There were significant differences between the two groups in terms of duration of operating time, duration of hospital stay, medical expenses. The number of fusion segments or kinds of instrumentation did not affect the fusion rate, time at which fusion was complete, or clinical outcomes. Metal failure rate of unilateral fixation was higher in patients with spondylolytic spondylolisthesis than in patients with spinal stenosis. CONCLUSIONS: Unilateral pedicle screw fixation was as effective as bilateral pedicle screw fixation in lumbar spinal fusion independent of the number of fusion segments (one or two segments) or pedicle screw systems. Unilateral pedicle screw fixation is not recommended for spondylolytic spondylolisthesis patients who were treated with Gill' s decompression.