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Proximal junctional problems are among the potential complications of surgery for adult spinal deformity (ASD) and are associated with higher morbidity and increased rates of revision surgery. The diverse manifestations of proximal junctional problems range from proximal junctional kyphosis (PJK) to proximal junctional failure (PJF). Although there is no universally accepted definition for PJK, the most common is a proximal junctional angle greater than 10° that is at least 10° greater than the preoperative measurement. PJF represents a progression from PJK and is characterized by pain, gait disturbances, and neurological deficits. The risk factors for PJK can be classified according to patient-related, radiological, and surgical factors. Based on an understanding of the modifiable factors that contribute to reducing the risk of PJK, prevention strategies are critical for patients with ASD.

Objective To compare the radiologic union rates between autogenous iliac crest bone graft (ICBG) and local bone graft in 1- to 3-level lumbar fusion. Methods We reviewed 178 consecutive patients who underwent 1- to 3-level lumbar fusion surgery because of lumbar spinal stenosis. Fusion status of the anterior or posterior column was evaluated by plain radiographs obtained at 24 months postoperatively. If at least either the anterior or posterior column was fused, that segment was regarded as having achieved fusion and was termed segment union. The definition of overall union was achieving union of all segments in a single patient. Results For each ICBG group and local bone graft group, fusion rate of the anterior and posterior column, and rate of the segments and overall union at postoperative 2 years were not different between the groups, regardless of surgery level. In the overall union rate according to the fusion level, the ICBG group showed constant overall fusion rate according to the fusion level (i.e., 96.9%, 96.9%, and 93.1% for 1-, 2-, and 3-level fusion), but tended to decrease with increasing level in the local bone graft group (100%, 95.8%, and 85.7% for 1-, 2-, and 3-level fusion, respectively) without statistically significant differences. Conclusions The union rate of 3-level fusion was not inferior to those of 1- or 2-level fusion in both ICBG and local bone graft patients. Local bone graft could be regarded as an adequate option for not only 1- or 2-level lumbar fusion but also 3-level lumbar fusion surgery.

Several studies have reported incidence and risk factors for the development of proximal junctional kyphosis (PJK) in patients with adolescent idiopathic scoliosis (AIS). However, there is little information regarding long-term follow-up after pedicle screw instrumentation (PSI) with rod derotation (RD) and direct vertebral rotation (DVR). Sixty-nine AIS patients who underwent deformity correction using PSI with RD and DVR were retrospectively analyzed in two groups according to the occurrence of PJK, with a minimum five-year follow-up, including a non-PJK group (n = 62) and PJK group (n = 7). Radiological parameters were evaluated at preoperative, postoperative, and last follow-up. Incidence for PJK was 10.1% (7/69 patients), with a mean 9.4-year follow-up period. The thoracolumbar/lumbar curve (TL/L curve) was proportionally higher in the PJK group. The proximal compensatory curve was significantly lower in the PJK group than in the non-PJK group preoperatively (p = 0.027), postoperatively (p = 0.001), and at last follow-up (p = 0.041). The development of PJK was associated with the TL/L curve pattern, lower preoperative proximal compensatory curve, and over-correction of the proximal curve for PSI with RD and DVR. Therefore, careful evaluation of compensatory curves as well as of the main curve is important to prevent the development of PJK in the treatment of AIS.

OBJECTIVE There have been no reports on the long-term radiographic outcomes of posterior vertebral column resection (PVCR) in patients with congenital scoliosis. The purpose of this study was to evaluate the surgical outcomes and complications after PVCR and its long-term effects on correcting this deformity in children with congenital scoliosis. METHODS The authors retrospectively analyzed the medical records of 45 patients with congenital scoliosis who were younger than 18 years at the time of surgery and who underwent PVCR and fusion with pedicle screw fixation (PSF). The mean age of the patients at the time of surgery was 11.3 years (range 2.4–18.0 years), and the mean length of follow-up was 12.8 years (range 10.1–18.2 years). RESULTS The mean Cobb angle of the main curve was 46.5° before PVCR, 13.7° immediately after PVCR, and 17.6° at the last follow-up. For the compensatory cranial curve, PVCR corrected the preoperative Cobb angle of 21.2° to 9.1° postoperatively and maintained it at 10.9° at the last follow-up. For the compensatory caudal curve, the preoperative Cobb angle of 23.8° improved to 7.7° postoperatively and was 9.8° at the last follow-up. The authors noted 22 complications, and the overall incidence of complications was 48.9%. CONCLUSIONS Posterior vertebral column resection is an effective procedure for managing congenital scoliosis in patients younger than 18 years. Use of PVCR and fusion with PSF for congenital scoliosis achieved rigid fixation and satisfactory deformity correction that was maintained over the long term. However, the authors note that PVCR is a technically demanding procedure and entails risks for major complications and excessive blood loss.

Background context There is little information regarding the surgical outcomes with regard to the timing of surgery in children under age 10 years for congenital scoliosis with a long-term follow-up. Purpose The purpose of this study was to compare the surgical outcomes for congenital scoliosis in children 6 years or older but less than 10 years of age. Study design This is a retrospective study. Patient sample Eighteen congenital scoliosis patients under age 10 years at the time of surgery were treated by posterior hemivertebra resection and bilateral pedicle screw fixation. Outcome measures Outcome measures are radiological outcomes (plain radiographs and computed tomography) and complications. Methods Eighteen congenital scoliosis patients (n=18) under age 10 years at the time of surgery were treated by posterior hemivertebra resection and bilateral pedicle screw fixation. These cases were retrospectively studied and had a minimum of 7-year follow-up. We assigned patients into two groups: Group 1 (n=9) patients who had surgery before 6 years of age and Group 2 (n=9) those who had surgery after 6 years of age. Results The groups were not found to be statistically different in operative time, blood loss, and follow-up period. In the Group 1, the mean Cobb angle of the main curve was 32.4° before surgery, 6.4° after surgery, and 9.1° at last follow-up. In the Group 2, the mean Cobb angle of the main curve was 36.5° before surgery, 10.4° after surgery, and 14.5° at last follow-up. There was significantly better deformity correction of main curve immediate postoperatively and at last follow-up in Group 1. No significant difference was observed in growth rate of the vertebral body and spinal canal parameters comparing the two groups at the vertebra with or without screws. There was no crankshaft phenomena, no clinical or radiographic features suggestive of spinal stenosis during follow-up, and no major vascular or neurological complications related to the pedicle screws in either group. Conclusions In congenital scoliosis patients, posterior hemivertebra resection after pedicle screw fixation before the age of 6 years had significantly better deformity correction and did not cause a negative effect on the growth of vertebral body or spinal canal compared with the group treated after 6 years of age. Therefore, early surgical correction of a congenital hemivertebra in children under 6 years of age, before structural changes occur, effectively achieves a more satisfactory correction without causing iatrogenic spinal stenosis or neurologic complications compared with children older than 6 years but under 10 years of age.

The rapid increase of elderly population has resulted in increased prevalence of adult scoliosis. Adult scoliosis is divided into adult idiopathic scoliosis and adult degenerative scoliosis. These two types of scoliosis vary in patient age, curve pattern and clinical symptoms, which necessitate different surgical indications and options. Back pain and deformity are major indications for surgery in adult idiopathic scoliosis, whereas radiating pain to the legs due to foraminal stenosis is what often requires surgery in adult degenerative scoliosis. When selecting a surgical method, major symptoms and underlying medical diseases should be carefully evaluated, not only to relieve symptoms but also to minimize postoperative complications. Surgical options for adult degenerative scoliosis include: decompression alone; decompression and limited short fusion; and decompression coupled with long fusion and correction of deformity. Decompression and limited short fusion can be applied to patients with a small Cobb's angle and normal sagittal imbalance. For those with a large Cobb's angle and positive sagittal imbalance, long fusion with correction of deformity is required. When long fusion is applied, a careful decision regarding the extent of fusion level should be made when selecting L5 or S1 as the distal fusion level and T10 or the thoracolumbar junction as the proximal fusion level. For the fusion extending to the sacrum, restoration of sagittal balance and rigid fixation with additional iliac screws should be considered. Any surgical procedures for adult degenerative scoliosis are known to have relatively high occurrences of complications; therefore, risks and benefits should be meticulously considered before selecting a surgical procedure.

Rationale: Congenital scoliosis due to a hemivertebra creates a wedge-shaped deformity, which progresses and causes severe spinal deformities as an individual grows. The treatment of congenital scoliosis focuses on early diagnosis and appropriate surgical management before the development of severe deformity. Patient concerns: We report the case of a 4-year-old male child with a left thoracolumbar scoliosis of 27° (T10-T12) due to a T11 hemivertebra who was treated by posterior fusion and pedicle screw fixation at the age of 4 years. The implant was removed due to pain secondary to implant prominence after 4 years without definitive revision surgery, which led to significant progression of the scoliosis, to 50°. The indication for posterior vertebral column resection (PVCR) is a congenital spinal deformity with a curve magnitude greater than 30° with fast progression. This includes documented progression of the curve by more than 5° in a 6- month period, failure of conservative treatment, or both. Outcomes: The patient underwent PVCR of the T11 hemivertebra. Nine years after the revision surgery with PVCR, the patient showed satisfactory results and his spine was well balanced. Lessons: This case shows that removal of an implant that was not the only cause of curve progression at a young age may lead to progression of scoliosis and, therefore, should be avoided unless it is absolutely necessary. Conclusion: Congenital scoliosis due to a hemivertebra at a young age could be treated by hemivertebra resection or anterior and posterior epiphysiodesis as definitive surgical treatment. The patient was eventually treated with PVCR, which achieved satisfactory correction without curve progression in a long-term follow-up.

STUDY DESIGN A retrospective comparative study. OBJECTIVE The aim of this study was to analyze the exact distal fusion level in the treatment of major thoracolumbar and lumbar (TL/L) adolescent idiopathic scoliosis (AIS) using rod derotation (RD) and direct vertebral rotation (DVR) following pedicle screw instrumentation (PSI). SUMMARY OF BACKGROUND DATA Proper determination of distal fusion level is a very important factor in deformity correction and preservation of motion segments in the treatment of major TL/L AIS. METHODS AIS patients with major TL/L curves (n = 64) treated by PSI with RD and DVR methods with a minimum 2-year follow-up were divided into AL3 (flexible) and BL3 (rigid) according to the flexibility and rotation by preoperative bending radiographs. RESULTS There was no significant difference in TL/L (major) curve between the AL3 and BL3 groups postoperatively (P = 0.933) and at the last follow-up (P = 0.144). In addition, there was no significant difference in thoracic (minor) and compensatory (caudal) curve postoperatively (thoracic curve: P = 0.828, compensatory curve: P = 0.976); however, there was a significant difference in compensatory (caudal) curve at the last follow-up (P = 0.041). The overall prevalence of unsatisfactory results was 28.1% (18/64 patients), and the prevalence was 15.2% (7/46) in the AL3 group and 61.1% (11/18) in the BL3 group, which was significantly different (P

Study design A retrospective study. Objective To compare the surgical outcomes of posterior vertebral column resection (PVCR) and its long-term effects on the deformity correction for congenital scoliosis in children less than 18 years of age. Summary of background data There have been no reports on surgical outcomes that pertain to the timing of surgery for congenital scoliosis in children under age 18 years with long term follow-up. Methods Forty-five congenital scoliosis patients (N = 45) under age 18 at the time of surgery were treated by PVCR. These cases were retrospectively studied and had a minimum 10-year follow-up. We assigned patients into two groups: Group 1 (N = 19) patients who had surgery before 10 years of age, Group 2 (N = 26) patients who had surgery after 10 years of age. Results In Group 1, the mean Cobb angle of the main curve was 44° before surgery, 10.2° after surgery, and 14.2° at last follow-up. In Group 2, the mean Cobb angle of the main curve was 48.7° before surgery, 17.2° after surgery, and 20.4° at the last follow-up. The mean operative time was 189 minutes in Group 1 and 245 minutes in Group 2. The mean estimated blood loss (EBL) per kilogram was 52.9 mL/kg in Group 1 and 48.1 mL/kg in Group 2. There were 22 complications for PVCR and the overall prevalence of complications was 48.9%. Conclusion PVCR is an effective procedure for the management of congenital scoliosis under age 18. PVCR for congenital scoliosis before the age of 10 years had significantly better deformity correction compared with the group after the age of 10 years and did not cause crankshaft phenomenon. Level of evidence 4.

The etiology of congenital scoliosis and its development remains unclear and has not yet been fully identified, even there are theories that congenital scoliosis could be derived from the failure of formation or failure of segmentation, which are etiologically heterogeneous with genetic, epigenetic, and environmental factors contributing to their occurrence. We reported a case of long-term follow-up after posterior vertebral column resection (PVCR) in both identical twins with similar congenital kyphoscoliosis at thoracolumbar levels. Twin I had been noticed by his parents to have asymmetry of his back at age 5 years, but no treatment was given. Twin II was first noticed to have a spinal problem at 11 years of age by his parents. Overtime, spine of both twins became further deviated to the left with kyphosis and was referred to our hospital. Both monozygotic twins were treated by PVCR and satisfactory results were demonstrated at 10-year follow-up. This case is the first report on the surgical treatment with PVCR, almost simultaneously, in both identical twins who had similar congenital vertebral anomalies causing kyphoscoliosis. Both identical twins with congenital kyphoscoliosis had undergone surgical correction by PVCR, anterior support with a mesh cage and posterior fusion using pedicle screws at the age of 14 years and achieved a satisfactory correction and a stable spine without curve progression with 10-year follow-up.

Study design A retrospective study of clinical results of operative treatment for degenerative lumbar scoliosis. Objective To determine the risk factors of sagittal decompensation after long instrumentation and fusion to L5 or S1. Summary of background data Little is known about the risk factors for sagittal decompensation, which was defined in this study as sagittal C7 plumb falling anterior >8 cm from the posterosuperior corner of the sacrum. Methods Forty-five patients (mean age: 64.4 year) with adult degenerative lumbar scoliosis were reviewed retrospectively with a minimum 2 years. The mean number of levels fused was 6.1 +/- 1.6 segments. The upper instrumented vertebra ranged from T9 to L2. The lower instrumented vertebra was L5 and S1 in 24 and 21 patients, respectively. Results Sagittal decompensation (SD) developed in 19 patients. The most significant risk factors of SD were preoperative sagittal imbalance and high pelvic incidence. The preoperative sagittal C7 plumb was more positive (67.9 mm) in the decompensation group than in the balance group (37.0 mm) (P = 0.002). There was a significant difference in pelvic incidence between 61.7 degrees in the decompensation and 54.9 degrees in the balance group (P = 0.01). The preoperative lumbar lordosis was hypolordotic in the decompensation group, however, it was not found to be a risk factor. Pseudarthrosis was identified at the lumbosacral junction in 5 patients, and 4 of them (80%) had SD. SD developed in 55% of patients who had loosening of the distal screws and 50% of patients with hypolordotic lumbar fusion. Distal adjacent segment disease was more likely to cause SD than proximal adjacent segment disease. Conclusion Sagittal decompensation is common after long posterior instrumentation and fusion for degenerative lumbar scoliosis. It is mostly associated with complications at the distal segments, including pseudarthrosis and implant failure at the lumbosacral junction. Restoration of optimal lumbar lordosis and secure lumbosacral fixation is necessary especially in patients with preoperative sagittal imbalance and high pelvic incidence in order to prevent sagittal decompensation after surgery.

Study design Retrospective study. Objective To evaluate the effect and outcome of thoracoplasty in conjunction with pedicle screw instrumentation in the treatment of thoracic adolescent idiopathic scoliosis (AIS). Summary of background data Some spine surgeons recently think more correction of hump deformity using pedicle screws without thoracoplasty. Although thoracoplasty has been conventional treatment of rib hump, there are few papers about the results of pedicle screw instrumentation and concomitant thoracoplasty. Methods Eighty-seven patients with thoracic AIS (mean age, 14.4 years) treated by pedicle screw instrumentation were retrospectively analyzed after a minimum follow-up of 2 years. Patients were divided into 3 groups; N-T group (no thoracoplasty with iliac bone graft, n = 37), T+N-DVR [thoracoplasty without direct vertebral rotation (DVR), n = 20] and T+DVR group (thoracoplasty with DVR, n = 30). In the T (T+N-DVR and T+DVR) group, 4 to 8 ribs were resected and used for bone graft. Patients were evaluated for deformity correction, balance, pulmonary function, height and angle of rib hump, clinical outcomes (SRS-30), and complications. Results In the N-T group, the thoracic curve was corrected from 53 degrees to 16 degrees (69% correction), in the T+N-DVR group from 55 degrees to 18 degrees (69%) and in the T+DVR group from 54 degrees to 10 degrees (81%). There was no difference in postoperative spinal balance and pulmonary function among the 3 groups. The correction rates of hump height and angle were 35% and 38% in the N-T group, respectively, 57% and 58% in the T+N-DVR, and 70% and 72% in the T+DVR. The T group showed significantly better correction of rib hump and self-image score in the SRS-30 questionnaire than the N-T group. There were 8 iliac donor site problems in the N-T group and 3 hemothorax in the T group, which had no adverse effect in the final result. Conclusion Thoracoplasty showed significantly better rib hump correction, satisfactory clinical outcomes without pulmonary function compromise, or iliac bone graft site morbidity in the treatment of thoracic AIS with pedicle screw instrumentation.

Retrospective study.To review the results and proximal adjacent problems of long fusion (more than 4 levels) according to the level of proximal fusion (L2~T9) in adult lumbar deformity using pedicle screw fixation.There are few written reports concerning proximal adjacent segmental failure according to the level of proximal fusion in adult lumbar deformity.The radiographs and clinical records of thirty-five patients (30 females, 5 males) of adult lumbar deformity with more than 2-year follow-up after surgery were analyzed. The average age was 62 years (range, 38~75). All patients were divided into three groups according to the level of proximal fusion: Group 1 (n=14) fusion up to L1 or L2; Group 2 (n=14) fusion up to T11 or T12; and Group 3 (n=7) fusion up to T9 or T10.The preoperative coronal curve of 28+/-14 degrees was corrected to 9+/-7 degrees immediately after surgery and 11+/-7 degrees at the final follow-up. The preoperative local kyphosis of 24+/-12 degrees was corrected to -1+/-10 degrees immediately after surgery and 1+/-11 degrees at the final follow-up. The lumbar lordosis was 14+/-18 degrees before surgery; 27+/-11 degrees after surgery; and 16+/-12 degrees at the final follow- up. The parameters of coronal and sagittal balance were improved in all patients after surgery, except one patient in group 2 who showed coronal imbalance due to over-correction. Sagittal imbalance at the most recent follow-up was detected in 10 patients with significant difference between the groups; 5 (36%) in Group 1, 5 (36%) in Group 2, and none in Group 3. Proximal adjacent segmental problems that are consisted with proximal disc degeneration with kyphosis, compression fractures above the fusion and screw failure proximal to the end of the fusion were observed in 15 patients with significant difference between the groups; 7 (50%) in Group 1, 7 (50%) in Group 2, and 1 (14%) in Group 3. There was 1 superficial infection and 2 transient neurologies.Fusion up to throacolumbar junction (L2~T11) in surgical treatment of adult lumbar deformity had more proximal adjacent problems with poorer results. Fusion higher than T10 is recommended for adult lumbar deformity.

With the advent of segmental pedicle screw fixation that enables more powerful corrective forces, it is postulated that an additional anterior procedure may be unnecessary even in severe deformities. The purpose of this paper is to evaluate the results of a posterior procedure alone using segmental pedicle screw fixation in severe scoliotic curves over 70 degrees . Thirty-five scoliosis patients treated by pedicle screw fixation and rod derotation were retrospectively analyzed after a minimum follow-up of 2 years (range 2-10.4). The mean age of patients was 15.3 years (range 9.8-34.2). Diagnoses were idiopathic scoliosis in 29, neuromuscular scoliosis in 3 and scoliosis associated with Marfan syndrome in 3. Scoliosis consisted of single thoracic curve in 18, double thoracic in 5 and double major in 12. Twenty-five patients showed a major thoracic curve greater than 70 degrees (range 70-100), and different ten patients showed a major lumbar curve greater than 70 degrees (range 70-105), pre-operatively. The deformity angle, lowest instrumented vertebral tilt (LIVT) and spinal balance were measured. Pre-operatively there were nine patients with coronal decompensation. The pre-operative thoracic curve of 80 +/- 9 degrees with the flexibility of 45 +/- 11% (45 +/- 11 degrees in side-bending film) was corrected to 27 +/- 10 degrees at the most recent follow-up, showing a correction of 66% (53 degrees) and loss of correction of 3.0% (3.7 degrees). The pre-operative lumbar curve of 79 +/- 12 degrees with the flexibility of 62 +/- 14% (30 +/- 11 degrees in side-bending film) was corrected to 33 +/- 14 degrees at the most recent follow-up [59% (46 degrees) curve correction, 3.5% (3.0 degrees) loss of curve correction]. The pre-operative LIVT of 30 +/- 8 degrees was corrected to 11 +/- 6 degrees, showing a correction of 62% (19 degrees). Residual coronal decompensation was observed in three patients postoperatively. Pre-operative thoracic kyphosis of 27 degrees (range 0-82) improved postoperatively to 31 degrees (range 14-53). In conclusion, posterior segmental pedicle screw fixation without anterior release in severe scoliosis had satisfactory deformity correction without significant loss of curve correction. In this series a posterior procedure alone obviated the need for the anterior release and avoided complications related anterior surgery.

A retrospective study.To evaluate the surgical outcomes of posterior hemivertebra resection and short segment fusion with segmental pedicle screw fixation in congenital scoliosis in children younger than 10 years.This is the first long-term follow-up on surgical outcomes of posterior hemivertebra resection and short segment fusion using segmental pedicle screw fixation in children younger than 10 years with congenital scoliosis.Patients with congenital scoliosis (n = 18) younger than 10 years at the time of the surgery were treated by posterior hemivertebra resection and bilateral pedicle screw fixation. The mean age at the time of surgery was 6.6 years (range, 2.6-9.8 yr). They were retrospectively studied with a mean follow-up of 11.4 years (range, 7.1-17.3 yr).The mean Cobb angle of the main curve was 34.4° before surgery, 8.6° after surgery, and 12.9° at last follow-up. In the compensatory cranial curve, the preoperative Cobb angle of 14.5° was corrected to 5.9° postoperatively and was 8.4° at last follow-up. In the compensatory caudal curve, the preoperative Cobb angle of 17.4° improved to 4° postoperatively and 6.6° at last follow-up. There were no crankshaft phenomena and no clinical and radiographical features suggestive of spinal stenosis during follow-up. There were no major vascular or neurological complications related to the pedicle screws.Posterior hemivertebra resection after pedicle screw fixation in congenital scoliosis is a safe and effective procedure that can achieve rigid fixation and deformity correction and restore spinal balance. This study showed that early posterior hemivertebra resection of congenital scoliosis before structural changes occur above or below can reduce fusion length, prevent curve progression, and effectively achieve a more satisfactory correction without hazardous iatrogenic spinal stenosis, crankshaft phenomena, or neurological complications.3.

STUDY DESIGN Retrospective study. OBJECTIVES To compare the surgical results between combined anterior-posterior procedures and posterior closing wedge osteotomy procedures in patients with posttraumatic kyphosis and neurologic compromise secondary to osteoporotic fractures. SUMMARY OF BACKGROUND DATA Combined anterior-posterior procedures are usually recommended in cases of kyphotic deformities with neurologic deficit secondary to osteoporosis. However, combined anterior-posterior surgery is associated with significant morbidity in elderly patients. MATERIALS AND METHODS Twenty-six patients with posttraumatic kyphosis and neurologic compromise secondary to osteoporotic fracture were indicated for operative intervention using either a combined anterior-posterior surgery (n = 11) or a posterior closing wedge osteotomy procedure (n = 15). The results of the two procedures were analyzed. The average patient age at the operation was 62.6 years (range: 50-82) with a 12:14 male-to-female ratio. Mean follow-up was 3.5 years (range: 2.1-5.4). Preoperative interval from injury to operation was 15.4 months (range: 1-36). There were 20 thoracolumbar (T12-L1) fractures and six lumbar fractures indicated for operative intervention. RESULTS In the combined anterior-posterior group, the mean operative time was 351 minutes with a mean blood loss of 2,892 mL. In the posterior closing wedge osteotomy group, the mean operative time was 215 minutes with blood loss of 1,930 mL. Eighteen patients showed a postoperative improvement in Frankel grading, 64% (7/11) in the combined anterior-posterior group, and 73% (11/15) in posterior closing wedge osteotomy group. There were no neurologic or vascular complications in either group. In the combined anterior-posterior group, there were five complications: two postoperative pneumonias, one superficial infection, and two distal screw loosening. There were only two complications in the posterior closing wedge osteotomy group: two distal screw loosening. One of the four cases of distal screw loosening required surgical revision. The other three cases were treated by bracing for more than 6 months. CONCLUSIONS Although technically demanding, the posterior closing wedge osteotomy procedure demonstrated a better surgical result with significant less mean operative time and mean blood loss (P < 0.05). It may be a better alternative than a combined anterior-posterior procedure in patients with posttraumatic kyphosis and neurologic compromise secondary to osteoporotic fracture.

Study design Retrospective study. Objectives To report a technique of vertebral column resection through a single posterior approach and its preliminary results in the treatment of moderate to severe spinal deformities with limited flexibility. Summary of background data Vertebral column resection is a formidable operation reserved for moderate to severe deformities with limited flexibility. The authors devised a technique of vertebral column resection through a single posterior approach that offers significant advantages over the anterior-posterior vertebral column resection. Methods Seventy spinal deformity patients treated by posterior vertebral column resection were reviewed. Minimum follow-up was 2 years (range 2-3.3 years). There were 34 males and 36 females with a mean age of 27.4 years at the time of the operation. Etiologic diagnoses were adult scoliosis in 7, congenital kyphoscoliosis in 38, and postinfectious kyphosis in 25. The surgery consisted of temporary stabilization of the vertebral column with segmental pedicle screw fixation, resection of the vertebral column at the apex of the deformity via the posterior route, followed by gradual deformity correction and global fusion. Results The total number of resected vertebrae was 143: 76 in thoracic and 67 in lumbar. Mean operation time was 4 hours, 31 minutes with average blood loss of 2333 mL. The deformity correction was 61.9% in the coronal plane and 45.2 degrees in the sagittal plane. Complications were encountered in 24 patients: 2 complete cord injuries in severe adult scoliosis and thoracic kyphosis patient who had significant preoperative cord compromise, 6 hematomas, 4 root injuries (all incomplete), 5 fixation failures, 2 infections, and 5 hemopneumothoraxes. Conclusions Posterior vertebral column resection is an effective alternative for moderate to severe deformities with limited flexibility. However, it is a technically demanding and exhausting procedure with possible risks for major complications.

Rationale: The management of congenital scoliosis concentrates on early diagnosis and proper surgical treatment before the development of severe deformities. Decision making regarding the appropriate fusion levels, proper surgical treatment, and reduction amount of kyphoscoliosis is very important but difficult in the treatment of congenital scoliosis, especially in young children. Patient concerns: We report an 11-year follow-up of revision surgery for fractional curve progression after combined anterior and posterior fusion without hemivertebra resection using pedicle screw fixation (PSF) in congenital kyphoscoliosis at age 4 years (a total 18-year follow-up). A T12 hemivertebra was documented in a 4-year-old girl and was treated by combined anterior and posterior fusion in two stages with PSF. The fusion mass was maintained but the distal compensatory curve progressed during the follow-up period. The patient underwent a posterior vertebral column resection (PVCR) with extended posterior fusion at the age of 11, 7 years after initial surgery. Outcomes: Eleven years after the revision surgery with PVCR, the patient showed satisfactory results and her spine was well balanced. Lessons: The cause of revision surgery for the curve progression may include inappropriate fusion level, incomplete hemivertebra resection, or failure of anterior and posterior fusion. Especially, inappropriate fusion level may result in deterioration of the compensatory curve even without progression of the fusion mass. Conclusion: Appropriate selection of fusion levels, complete resection of hemivertebra, and satisfactory reduction of scoliosis and kyphosis are important factors for deformity correction and prevention of progression of both main and compensatory curves (adding-on of structural curve or progression of compensatory curve) as well as reducing the influence of adjacent vertebral growth using as short a fusion as possible.

STUDY DESIGN A retrospective study. PURPOSE To determine the exact distal fusion level in the management of thoracolumbar/lumbar adolescent idiopathic scoliosis (TL/L AIS) using pedicle screw instrumentation (PSI). OVERVIEW OF LITERATURE The selection of distal fusion level remains controversial in TL/L AIS. METHODS Radiographic parameters of 66 TL/L AIS patients were analyzed. The patients were grouped according to the distal fusion level; L3 group (fusion to L3, n=58) and L4 group (fusion to L4, n=8). The L3 group was subdivided into L3A (L3 crosses the mid-sacral line with rotation of less than grade II, n=33) and L3B (L3 does not cross the mid-sacral line or rotation is grade II or more, n=25) based on both bending radiographs. All of the patients in the L4 group had the same location and rotation of L3 in bending films as that of patients in the L3B group. An unsatisfactory result was defined as a lowest instrumented vertebral tilt (LIVT) of more than 10° or coronal balance of more than 15 mm. RESULTS Among the 3 groups, there was a significantly lesser correction in the TL/L curve and LIVT in the L3B group. Unsatisfactory results were obtained in 3 patients (9.1%) of the L3A group, in 15 patients (68.2%) of the L3B group, and in 1 patient (12.5%) of the L4 group with a significant difference. CONCLUSIONS In TL/L AIS treatment with PSI, the curve can be fused to L3 with favorable radiographic outcomes when L3 crosses the mid-sacral line with rotation of less than grade II in bending films. Otherwise, fusion has to be extended to L4.

STUDY DESIGN This is a retrospective study analyzing 76 patients treated by decompression, pedicle screw instrumentation, and fusion for spondylolytic spondyiolisthesis with symptomatic spinal stenosis. OBJECTIVES To verify the advantages of adding posterior lumbar interbody fusion to the usual posterolateral fusion with pedicle screw instrumentation. SUMMARY OF BACKGROUND DATA Stabilization after decompression of spondylolytic spondylolisthesis is difficult because of a lack of fusional bone bases, gap between the transverse process bases, and incompetent anterior disc support. Posterior lumbar interbody fusion offers anterior support, reduction, and a broad fusion base. METHODS Forty patients were treated with posterolateral fusion, and 36 were treated with additional posterior lumbar interbody fusion. They were compared for union, reduction of the deformity, and clinical results. RESULTS The patients were followed up for more than 2 years. Nonunion was observed in three patients who underwent posterolateral fusion (7.5%), and no cases of nonunion was found in patients who underwent posterior lumbar interbody fusion. Reduction of slippage was 28.3% in those who underwent posterolateral fusion and 41.6% in those who had posterior lumbar interbody fusion (P = 0.05). In the posterolateral fusion group, eight patients (20%) had recurrence of deformity, with loss of reduction more than 50%. Hardware failures occurred in two patients who had posterolateral fusion. There was no major neurologic complications in both groups. Both groups had satisfactory results in more than 90% of patients, with marked improvement of claudication. However, subjective improvement of back pain by Kirkaldy-Willis criteria revealed differences in the excellent results. An excellent result was reported by 45% in the posterolateral fusion group and by 75% in posterior lumbar interbody fusion group. CONCLUSIONS The addition of posterior lumbar interbody fusion to posterolateral fusion after a complete decompression and pedicle screw fixation is a recommended procedure for the treatment of spondylolytic spondylolishesis with spinal stenosis.

IntroducionThere is little information reported about the long term follow-up of surgical outcomes that pertain to the timing of surgery for congenital scoliosis in children under age 20 years. Thi...

Study Design Retrospective study. Purpose To evaluate the incidence and risk factors of complications following posterior vertebral resection (PVR) for spinal deformity. Methods A review of 233 patients treated with PVR at one institution over a nine-year period (1997 to 2005) was performed. The average age was 33.5 years. Complications were assessed in terms of surgical techniques (posterior vertebral column resection [PVCR] and decancellation osteotomy) and etiologies of deformity. Results Local kyphosis was corrected from 51.4° to 2.7°, thoracic scoliosis 63.9° to 24.5° (62.6% correction), and thoracolumbar or lumbar scoliosis 50.1° to 17.1° (67.6%). The overall incidence of complications was 40.3%. There was no significant difference between PVCR and decancellation osteotomy in the incidence of complications. There were more complications in the older patients (>35 years) than the younger (p < 0.05). Hig her than 3,000 ml of blood loss and 200 minutes of operation time increased the incidence of complications, with significant difference (p < 0.05). More than 5 levels of fusion significantly increased the total number of complications and postoperative neurologic deficit (p < 0.05). Most of the postoperative paraplegia cases had preoperative neurologic deficit. Preoperative kyphosis, especially in tuberculous sequela, had hig her incidences of complications and postoperative neurologic deficit (p < 0.05). More than 40° of kyphosis correction had the tendency to increase complications and postoperative neurologic deficit without statistical significance (p > 0.05). There was 1 mortality case by heart failure. Revision surgery was performed in 15 patients for metal failure or progressing curve. Conclusions The overall incidence of complications of PVR was 40.3%. Older age, abundant blood loss, preoperative kyphosis, and long fusion were risk factors for complications.

There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4-8) in the L5 group and 6.09 (range 4-9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7 degrees before surgery to 6.8 degrees after surgery in the L5 group, and from 22.8 degrees to 7.7 degrees in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at L5-S1 and loosening of L5 screws. Seven of the nine patients showed preoperative sagittal imbalance and/or lumbar hypolordosis, which might be risk factors of complications at L5-S1. For the patients with sagittal imbalance and lumbar hypolordosis, L5-S1 should be included in the fusion even if L5-S1 disc was minimal degeneration.

Study design Radiographic analysis was performed retrospectively. Outcomes and complications were collected prospectively. Objectives To assess complications after posterior fusion and instrumentation for degenerative lumbar scoliosis, to determine risk factors of complications, and to analyze the clinical outcomes of surgery. Summary of background data The complications after degenerative lumbar scoliosis surgery have reported to be high. Risk factors for developing complications are unknown. Methods Forty-seven patients (average age, 66.6 years; range, 48-83 years) with degenerative lumbar scoliosis undergoing posterior fusion and instrumentation were analyzed. Seven patients had additional posterior lumbar interbody fusion at the lumbosacral junction. The average number of levels fused was 4.7 +/- 2.2 segments. We evaluated the early perioperative ( Results There were 14 early perioperative complications and 18 late complications. There was 1 case of mortality by pulmonary embolism. Early complications included ileus, urinary tract infection, transient delirium, superficial infection, and neurologic deficit. Late complications included adjacent segment diseases, pseudarthrosis, and loosening of screws. Adjacent segment disease developed at the proximal segment in 10 patients and at the distal segment in 5 patients. Pseudarthrosis was noted at the lumbosacral junction in 2 patients. Revision surgery was performed in 7 patients. Older patients (>65 years) had the tendency to increase early complications without statistical difference (P = 0.053). Excessive intraoperative blood loss was the most significant risk factor for the development of early perioperative complications, and number of levels fused was related to blood loss. Operative time and multiple medical comorbidities were not associated with higher complication rate. There were no specific factors related to the development of late complications. Conclusion The complication rate after posterior fusion and instrumentation for degenerative lumbar scoliosis was 68%. Abundant blood loss was a significant risk factor for early perioperative complications. The improvement of Oswestry disability index was less in patients with late complications.

The extent of fusion for degenerative lumbar scoliosis has not yet been determined. The purpose of this study was to compare the results of short fusion versus long fusion for degenerative lumbar scoliosis. Fifty patients (mean age 65.5 +/- 5.1 years) undergoing decompression and fusion with pedicle screw instrumentation were evaluated. Short fusion was defined as fusion within the deformity, not exceeding the end vertebra. Long fusion was defined as fusion extended above the upper end vertebra. The lower end vertebra was included in the fusion in all the patients. The short fusion group included 28 patients and the long fusion group included 22 patients. Patients' age and number of medical co-morbidities were similar in both the groups. The number of levels fused was 3.1 +/- 0.9 segments in the short fusion group and 6.5 +/- 1.5 in the long fusion group. Before surgery, the average Cobb angle was 16.3 degrees (range 11-28 degrees ) in the short fusion group and 21.7 degrees (range 12-33 degrees ) in the long fusion group. The correction of the Cobb angle averaged 39% in the short fusion group and 72% in the long fusion group with a statistical difference (P = 0.001). Coronal imbalance improved significantly in the long fusion group more than in the short fusion group (P = 0.03). The correction of lateral listhesis was better in the long fusion group (P = 0.02). However, there was no difference in the correction of lumbar lordosis and sagittal imbalance between the two groups. Ten of the 50 patients had additional posterolateral lumbar interbody fusion at L4-5 or L5-S1. The interbody fusion had a positive influence in improving lumbar lordosis, but was ineffective at restoring sagittal imbalance. Early perioperative complications were likely to develop in the long fusion group. Late complications included adjacent segment disease, loosening of screws, and pseudarthrosis. Adjacent segment disease developed in ten patients in the short fusion group, and in five patients in the long fusion group. In the short fusion group, adjacent segment disease occurred proximally in all of the ten patients. Loosening of distal screws developed in three patients, and pseudarthrosis at L5-S1 in one patient in the long fusion group. Reoperation was performed in four patients in the long fusion group and three patients in the short fusion group. In conclusion, short fusion is sufficient for patients with small Cobb angle and good spinal balance. For patients with severe Cobb angle and rotatory subluxation, long fusion should be carried out to minimize adjacent segment disease. For patients who have severe sagittal imbalance, spinal osteotomy is an alternative technique to be considered. As long fusion is likely to increase early perioperative complications, great care should be taken for high-risk patients to avoid complications.

Introduction There is no report on the effect of DVR on the shoulder balance using segmental pedicle screw instrumentation in the treatment of double thoracic adolescent idiopathic scoliosis (AIS) with minimum 5-year follow-up. This study is to evaluate the shoulder balance resulting from the correction of double thoracic AIS comparing rod derotation (RD) with direct vertebral rotation (DVR) and RD only following pedicle screw instrumentations. Materials and Methods Double thoracic AIS patients ( n = 57) were treated by fusing both thoracic curves with RD and DVR ( n = 35), or RD ( n = 22) methods and retrospectively studied with a minimum 5 years follow-up. Results In the RD with DVR group, the preoperative PT curve of 40.2 degrees improved to 17.9 degrees postoperatively and 19.9 degrees at last follow-up. In the RD group, the preoperative PT curve of 37.5 degrees improved to 22.4 degrees postoperatively and 23.2 degrees at last follow-up. In the RD with DVR group, the preoperative DT curve of 56.6 degrees improved to 16.1 degrees postoperatively and 16.7 degrees at last follow-up. In the RD group, the preoperative DT curve of 50.6 degrees improved to 17.8 degrees postoperatively and 18.2 degrees at last follow-up. In the RD with DVR group, the average preoperative SHD of 16.3 mm was improved to 7.2 mm postoperatively and was 7.0 mm at last follow-up. In the RD group, the average preoperative SHD of 15.1 mm was changed to 7.5 mm postoperatively and was 7.3 mm at last follow-up. Conclusion Shoulder balance was not significantly improved even with additional correction method of DVR using segmental pedicle screw instrumentation in double thoracic AIS. The PT curve was rigid and corrected less in both groups. Therefore, less correction of the DT curve effectively achieves better shoulder balance.

STUDY DESIGN Retrospective study. OBJECTIVES To report the results and the technique of posterior vertebral column resection (PVCR) in fixed lumbosacral deformity. SUMMARY OF BACKGROUND DATA Fixed lumbosacral deformity has gross imbalance as well as progressive compensatory thoracolumbar deformity because of the absence of a mobile spine caudally. There is no consensus of the surgical treatment of fixed lumbosacral deformity. Fixed lumbosacral deformity can be managed by PVCR, which not only corrects the deformity but also restores the trunk balance by translation of spinal column. METHODS Twenty-five consecutive fixed lumbosacral deformity patients subjected to PVCR were reviewed after a minimum follow-up of 2 years. The apical vertebra and the ultimately resected vertebra were below L4 in most cases. Etiologic diagnoses were congenital scoliosis in 6, congenital kyphoscoliosis in 3, post-traumatic kyphosis in 2, and postinfectious kyphosis in 14. The average age at the operation was 38 years (range, 2.5-61 years) with a male:female ratio of 7:18. The indication for PVCR was fixed lumbosacral deformities that could not be brought to a reasonable balance on traction or forced side bending. Before surgery, 12 patients (48%) presented with neurologic compromise and 20 patients (80%) presented with intractable back pain. The surgical technique consisted of segmental pedicle screw fixation, decompression of neural structures, and resection of the vertebral column at the apex of the deformity via the posterior route, followed by deformity correction and global fusion. During the resection, all the nerve roots were preserved. RESULTS Two and one tenth (2.1) vertebrae removed on average (range, 1-5 vertebrae), and 52 in all. The average fusion extent was 4.5 vertebrae (range, 2-8 vertebrae). The anterior column reconstruction was carried out with autogenous bone graft in all patients and additional insertion of titanium mesh in 12. The distal anchor went down to L5 in 4 patients, S1 in 12, and S2 in 9. Preoperative scoliosis of 38 degrees +/- 12 degrees was corrected to 15 degrees +/- 8 degrees (60% correction) at most recent follow-up, and preoperative kyphosis of 35 degrees +/- 25 degrees was corrected to -5 degrees +/- 11 degrees (40 degrees correction). The compensatory coronal curve of 26 degrees was spontaneously corrected to 12 degrees at most recent follow-up. The preoperative thoracic lordosis of -16 degrees was corrected to 4 degrees at most recent follow-up, and the preoperative lumbar kyphosis of 20 degrees was corrected to -17 degrees . Preoperative coronal imbalance of 2.0 cm was improved to 0.9 cm at most recent follow-up, and preoperative sagittal imbalance of 9.3 cm was improved to 4.6 cm. Mean operation time was 280 minutes with a blood loss of 2,810 mL. The preoperative neurologic compromise was improved in all patients, and pain was reduced to less than half of preoperative visual analog analog scale in 17 patients. The following complications were encountered in 5 patients: 2 with transient neurology that spontaneously improved without a sequel within 6 months, 2 with compression fractures at proximal adjacent vertebra, and 1 with pseudarthrosis. CONCLUSIONS PVCR is an effective procedure for the management of fixed lumbosacral deformity. It provides satisfactory correction and improved functional outcomes. However, it is a technically demanding and exhausting procedure with possible risks for complications.

Study design Retrospective study. Objective To report on the technique and results of posterior vertebral column resection (PVCR) for severe rigid scoliosis. Summary of background data The treatment of severe rigid scoliosis is a demanding surgical challenge. Conventional procedures such as combined anteroposterior instrumentation enable limited correction. In rigid scoliosis, vertebral column resection is a better option for accomplishing translation of spinal column. PVCR is performed through a single posterior approach. Methods A total of 16 patients with scoliosis (average age 29 years) subjected to PVCR were retrospectively reviewed after a minimum follow-up of 2 years (range 2-6.8). The indication for PVCR was scoliosis more than 80 degrees , with flexibility less than 25%. The radiographic parameters were evaluated, and clinical records were reviewed. Results The number of vertebrae removed averaged 1.3, and 21 total (15 thoracic and 6 lumbar). Average fusion extent was 10.6 vertebrae. The mean preoperative scoliosis of 109.0 degrees was corrected to 45.6 degrees (59% correction) at the most recent follow-up, and the minor curve of 59.3 degrees was corrected to 29.2 degrees (51% correction). The mean preoperative coronal imbalance of 4.0 cm was improved to 1.0 cm at the most recent follow-up, and sagittal imbalance of 4.2 cm was improved to 1.6 cm. Complications were encountered in 4 patients, including 1 complete paralysis, 1 hematoma, 1 hemopneumothorax, and 1 proximal junctional kyphosis. Conclusions PVCR is an effective alternative for severe rigid scoliosis. It is a highly technical procedure and should only be performed by an experienced surgical team.

STUDY DESIGN A retrospective study was conducted. OBJECTIVE To determine the exact distal fusion level in the treatment of single thoracic idiopathic scoliosis (King Types 3 and 4) with segmental pedicle screw fixation. SUMMARY OF BACKGROUND DATA Pedicle screw fixation effectively shortens the distal fusion extent by improved three-dimensional deformity correction. However, the selection of distal fusion extent remains controversial in single thoracic idiopathic scoliosis. METHODS This study analyzed 42 patients with single thoracic adolescent idiopathic scoliosis (32 King 3 patients and 10 King 4 patients) who underwent segmental pedicle screw fixation and had a minimum follow-up period of 2 years (range, 2-6 years). The patients were grouped according to the distal fusion level with reference to the standing neutral rotated vertebra (NV) for comparison of deformity correction and spinal balance using standing radiographs. Failure to restore an adequate trunk balance and progression or extension of the primary curve (adding on) was considered unsatisfactory. RESULTS Preoperative 50 degrees +/- 11 degrees of thoracic deformity was corrected to 13 degrees +/- 5 degrees, for a curve correction of 74%. Preoperative 23 degrees +/- 7 degrees of lumbar deformity was corrected to 2 degrees +/- 8 degrees, for a curve correction of 93%. Curve correction was not significantly affected by King type or distal fusion level (P > 0.05). Postoperative unsatisfactory results were obtained in 14 patients. When the preoperative NV was the same or one level distal to end vertebra (EV), fusion down to NV was satisfactory (14/14). When the preoperative NV was more than two levels distal to EV, fusion down to one level shorter than NV (NV-1) also was satisfactory (9/9). However, when fusion down to NV-2 or shorter was performed, the chances of adding on were higher (14/19; P < 0.01). Preoperative 17 degrees +/- 8 degrees of thoracic kyphosis was improved to 24 degrees +/- 7 degrees. CONCLUSIONS In single thoracic idiopathic scoliosis, NV is an important factor for the determination of fusion level. When preoperative NV and EV show no more than two-level gap differences, the curve should be fused down to NV. When the gap is more than two levels, fusion down to NV-1 is satisfactory, saving one or two motion segments, as compared with fusion extending to the stable vertebra.

Study Design: This is a retrospective study. Objectives: We wanted to assess the stability of distal instrumentation using the bilateral S1 and sacral alar screws for the treatment of degenerative lumbar deformity. Summary of the Literature Review: Various instrumentation methods have been introduced for increasing the strength of lumbosacral fusion. However, there are not many clinical studies that have evaluated the effectiveness of a sub-S1 alar screw for treating degenerative lumbar deformity surgery. Materials and Methods: A total of 39 patients with degenerative lumbar deformity were treated by long fusion and we retrospectively analyzed these patients after a minimum follow-up of 1 year. All the patients underwent an operation with distal instrumentation using either bilateral S1 screws alone (the S1 group) or additional bilateral sub-S1 sacral alar screws (the SA group). There were 19 patients in the S1 group and 20 patients in the SA group. The stability of the distal instrumentation was assessed by breakage or backout of a rod and/or screws based on simple radiography. Results: Instability of the distal instrumentation was detected in 6 cases (32%) in the S1 group and in 1 case (5%) in the SA group. The SA group had a more stability of the distal instrumentation than that of the S1 group with a significant difference (P 0.05). Conclusions: Bilateral sacral alar screws coupled with bilateral S1 screws can provide good distal fixation for stability of the distal instrumentation when performing long fusion for treating degenerative lumbar deformity.

Purpose: To analyze survival rates of patients after mono-segmental lumbar or lumbosacral fusion and to evaluate factors affecting the revision operation due to adjacent segmental degeneration. Materials and Methods: This study enrolled 1,206 patients who had mono-segmental lumbar or lumbosacral fusion between March 1997 and December 2006 at the Seoul Spine Institute. The survival rates for the revision operation due to adjacent segmental degeneration were analyzed retrospectively. The age at index operation, sex, etiologic diagnosis, fusion method, fusion level, substance of bone graft, operator, body mass index (BMI), and smoking were considered as risk factors for the revision operation. Results: There were 27 patients with a revision operation for adjacent segmental degeneration (2.24%). The average follow-up period was 39.0 months (6 months to 12 years 6 months) and the average age at operation was 47.0 years (13 to 85 years). The sur vival rate at 5 years was 97.3%, and at 10 years it was 89.4%. Patients less than 50 years old had a significantly lower revision operation rate than those aged 50 or more (p=0.002). When fusion between the 4th lumbar and the 5th lumbar spinal vertebrae was done, the revision operation rate was significantly higher than for other levels (p=0.003). Obese patients with had a significantly higher revision rate than did patients with BMI0.05). In multivariate analysis, age alone was a significant risk factor (p=0.048, Hazard ratio=2.50). Conclusion: The most important factor for survival without revision surgery for adjacent segmental degeneration following instrumented mono-segment lumbar or lumbosacral fusion is the age at index operation. Patients 50 year-old or older should be informed of the possibility of adjacent segmental disease after instrumented mono-segment lumbar or lumbosacral fusion.

Objectives : To report the surgical technique and effectiveness in treating rigid adult scoliosis with one stage vertebral column resection and pedicle screw fixation through a single posterior approach(PVCR). Materials and Methods : Twenty-one patients with low flexibility(less than 20~30%) subjected to PVCR were evaluated after a mean follow-up of 18.5 months(12~29 months). There were 10 males and 11 females. The mean age at the time of the operation was 32.1 years(19~61 years). Etiological diagnoses were idiopathic in 7, congenital in 12, neuromuscular in 2. Preoperatively, all the patients showed moderate to severe derangement of pulmonary function with reduced vital capacity(30%~57%). Results : An average of 1.3 vertebrae(1~3 vertebrae) were removed. The resection of body was in thoracic in 12 and lumbar in 15. Posterior fusion was carried out in 6.8(3~12) levels. Following the surgery, preoperative thoracic scoliosis of 86 (55~130 ) and lumbar scoliosis of 64 ( 3 5~1 1 0 ) were corrected to 38 ( 1 5~6 5 ) and 25 ( 1 4~6 1 ), showing a correction of 56.2%(39~78%) and 6 1 . 1 % ( 4 4~82%) respectively. Preoperative kyphosis of 59 ( 1 6~1 0 4 ) was corrected to 24 ( 2~5 8 ), showing a correction of 60.2%(41~74%). Preoperative coronal imbalance and shoulder height difference was corrected to 0.6 cm and 1.0 cm respectively. The average operation time and transfusion were 253 minutes and 2835 ml. The complications comprised two transient neurological deficits, one aggravated neurological deficits, one monoparesis, one infection, and one pneumothorax. Conclusion : One stage posterior vertebral column resection is a promising new technique for rigid scoliosis, significantly reducing the operative time and morbidity of combined anterior-posterior resection.

Materials a and M Methods: The sagittal curves were analyzed in normal adolescents (N-adol group, n=23) and patients with thoracic AIS (AIS group, n=26) who had thoracic curves ≥ 45� . Lateral standing radiographs of the cervical spine with a elbow straight and the whole spine with the hands on the clavicles were taken. The sagittal curves and balance were measured in the following segments; C2-C7, T2-T5, T5-12, T2-12, T12-S1. Cervical lordosis (C2-C7) was measured in both cervical spine radiographs and whole spine radiographs. Results: In the N-adol group, the cervical lordosis was 9.2±14.6�in the cervical spine radiographs and -0.6±12.9�(‘-’ means kyphosis) in whole spine radiographs. In the AIS group, cervical lordosis was -5.0±12.9�in the cervical radiographs and -8.1± 12.7�in the whole radiographs. The AIS group had significantly less cervical lordosis than the N-adol group. Thoracic kyphosis of T5-12 and T2-12 was 24.1±10.6�and 38.9±13.1�in the N-adol group, respectively, and 17.8±9.4�and 30.1±11.8�in the AIS group, respectively. There was a significant difference between the two groups (Ps 0.05). In the AIS group, the cervical lordosis measured in the cervical spine radiograph showed a positive correlation with thoracic kyphosis of T2-5 (r=0.50, P=0.009) and T2-12 (r=0.57, P=0.003). Conclusions: AIS patients had significantly less cervical lordosis and thoracic kyphosis than normal adolescents. Decreased cervical lordosis in AIS had a significant correlation with their relative thoracic hypokyphosis.

Purpose: Adjacent segment disease (ASD) is major complication following spinal instrumentation and fusion. The purpose of the current study was to determine the prevalence and risk factors of proximal ASD following posterior instrumentation and fusion for degenerative lumbar scoliosis. Materials and Methods: Seventy-two patients (mean age 64.8 years) who had undergone decompression and fusion with pedicle screw instrumentation were evaluated. The average follow-up was 4.7 years. Twenty-five patients had additional interbody fusion at the lower lumbar spine. The average number of levels fused was 5.1 segments (range 1-9). The upper instrumented vertebrae ranged from T9 to L4. The lower instrumented vertebrae were L5 and S1. Results: Proximal ASD developed in 17 (24%) of 72 patients, including compression fractures (n=6), junctional kyphosis (n=5), spinal stenosis (n=4), and symptomatic disc collapse (n=2). The preoperative scoliotic angle, lumbar lordosis, thoracic kyphosis, and coronal and sagittal C7 plumb were not associated with the development of proximal ASD. There was a close correlation between the level of the upper instrumented vertebrae and the development of ASD (p=0.001). When fusion did not extend beyond the lumbar vertebra, ASD occurred in 15 (38.5%) of 39 patients. In contrast, when fusion extended up to the thoracic vertebrae, ASD occurred in 2 (6.1%) of 33 patients. The improvement in the Oswestry score was superior to the group without ASD (p=0.001). Conclusion: The prevalence of symptomatic ASD at the proximal segment was 24% after posterior instrumentation and fusion for degenerative lumbar scoliosis. The cephalad extent of fusion was the most significant risk factor for the development of proximal ASD.

Because platelets and muscle cells share the same contractile proteins - actin and myosin - platelets may serve as a model for muscle research. To study the functional abnormalities and ultrastructural changes of platelets and to determine whether or not abnormalities in muscle contractile proteins and collagen play an important role in the pathogenesis of idiopathic scoliosis, the bleeding time, the platelet aggregation test, and the titers of platelet plasminogen activator inhibitors were measured and the electron microscopic findings were examined in 52 idiopathic scoliosis patients aged 7 to 28 years and in 49 normal individuals aged 8 to 38 years as a control group. We found no statistically significant difference between the two groups in the bleeding time, the platelet aggregation test, and the titers of platelet plasminogen activator inhibitors. In the electron microscopic findings, no specific abnormalities were found in platelets of idiopathic scoliosis patients. We concluded that idiopathic scoliotic patients have normal morphology and function of platelets, and there is no important role of contractile proteins in the pathogenesis of idiopathic scoliosis. In addition, since the bleeding time was in the normal range, no evidence of subendothelial collagen dysfunction was found in the idiopathic scoliosis patients.

Study Design: Retrospective study Objectives: To evaluate the surgical outcome of congenital scoliosis with a hemivertebra treated by posterior hemivertebra excision and pedicle screw instrumentation. Summary of Literature Review: Posterior hemivertebra excision can be accomplished through a single posterior approach, and excellent correction and outcome may be achieved. Materials and Methods: Forty patients with one fully segmented hemivertebra treated by posterior hemivertebra excision with pedicle screw instrumentation were retrospectively analyzed after a minimum follow-up of 2 years (range 2~7.7 years). The mean age at surgery was 15.9 years (range 2.6~37.9 years). Preoperative and postoperative standing radiographs were used to assess radiographic parameters. Results: The average number of vertebrae in the major curve was 4.2 (range 3~8), and the average flexibility was 29% (range 8~59%). The average length of fusion was 3.5 segments (range 1~6). The number of fused vertebrae had a positive correlation with age at the index surgery (r=0.345, p�0.05). Mean preoperative scoliosis of 48±12。was corrected to a mean of 17±10。 (65% correction), and mean preoperative kyphosis of 46±18。was corrected to a mean of 12±12。at the most recent follow-up. The compensatory curve had a mean of 25±10。preoperatively and spontaneously corrected to a mean of 8±8。(70% correction) at the most recent follow-up. The mean operating time was 233±81 min, with an average blood loss of 2904 ml. There was neither crankshaft phenomenon nor iatrogenic spinal stenosis in 6 patients under the age of 5 years after an average follow-up of 6 years. Conclusions: Posterior hemivertebra excision using pedicle screw instrumentation in congenital scoliosis due to a hemivertebra is a safe and effective procedure. Posterior hemivertebra excision at an early age may reduce the fusion length while avoiding the induction of iatrogenic spinal stenosis during follow-up.

Purpose: Adjacent segment disease (ASD) is major complication following spinal instrumentation and fusion. The purpose of the current study was to determine the prevalence and risk factors of proximal ASD following posterior instrumentation and fusion for degenerative lumbar scoliosis. Materials and Methods: Seventy-two patients (mean age 64.8 years) who had undergone decompression and fusion with pedicle screw instrumentation were evaluated. The average follow-up was 4.7 years. Twenty-five patients had additional interbody fusion at the lower lumbar spine. The average number of levels fused was 5.1 segments (range 1-9). The upper instrumented vertebrae ranged from T9 to L4. The lower instrumented vertebrae were L5 and S1. Results: Proximal ASD developed in 17 (24%) of 72 patients, including compression fractures (n=6), junctional kyphosis (n=5), spinal stenosis (n=4), and symptomatic disc collapse (n=2). The preoperative scoliotic angle, lumbar lordosis, thoracic kyphosis, and coronal and sagittal C7 plumb were not associated with the development of proximal ASD. There was a close correlation between the level of the upper instrumented vertebrae and the development of ASD (p=0.001). When fusion did not extend beyond the lumbar vertebra, ASD occurred in 15 (38.5%) of 39 patients. In contrast, when fusion extended up to the thoracic vertebrae, ASD occurred in 2 (6.1%) of 33 patients. The improvement in the Oswestry score was superior to the group without ASD (p=0.001). Conclusion: The prevalence of symptomatic ASD at the proximal segment was 24% after posterior instrumentation and fusion for degenerative lumbar scoliosis. The cephalad extent of fusion was the most significant risk factor for the development of proximal ASD.

Purpose: To compare the results of two different surgical methods (translation vs rod derotation) in a correction of double thoracic adolescent idiopathic scoliosis (AIS) using pedicle screw instrumentation. Materials and Methods: Forty-seven patients with double thoracic AIS treated by pedicle screw instrumentation were reviewed retrospectively after a minimum follow-up of 2 years. The patients were divided into two groups; TR group (translation method, n=14) and RD group (rod derotation, n=33). There were no significant differences in the preoperative curve characteristics between the two groups. Results: In the TR group, the preoperative upper thoracic curve of 37±4˚ improved to 24±4˚ (35% correction), and the lower thoracic curve of 52±9˚ improved to 18±5˚ (65% correction). In the RD group, the preoperative upper thoracic curve of 40±7˚ improved to 19±7˚ (51% correction), and the lower thoracic curve of 56±12˚ was improved to 16±6˚ (72% correction). The correction of the upper and lower thoracic curves was significantly better in the RD group (p

Purpose: To compare the results of short fusion versus long fusion for degenerative lumbar scoliosis. Materials and Methods: Forty-seven patients undergoing short fusion (n=28) and long fusion and instrumentation (n=19) were evaluated. Short fusion was defined as fusion within the deformity, not exceeding the upper end vertebra. Long fusion was defined as fusion extended above the upper end vertebra. The number of levels fused in the short and long fusion groups was 3.14 and 6.89 segments, respectively. Results: Before surgery, the Cobb angle was 16.3o in the short fusion group and 22o in the long fusion group, which changed to 10.1o and 8.47o, respectively, at the last visit. The correction of coronal imbalance was better in the long fusion group. In contrast, the correction of sagittal imbalance was similar in both groups. The mean estimated blood loss in the short and long fusion groups was 1,671 ml and 2,742 ml, respectively. Early perioperative complications developed frequently in the long fusion group. Adjacent segment disease occurred more frequently in the short fusion group. Conclusion: Long fusion and instrumentation for degenerative lumbar scoliosis was better at correcting the coronal deformity and imbalance than short fusion but was ineffective in correcting the sagittal imbalance.

Purpose : To assess the results of double thoracic fusion using pedicle screw instrumentation fused proximally to T1 or T2 in patients with double thoracic adolescent idiopathic scoliosis (AIS). Materials and Methods : Forty patients with double thoracic AIS were analyzed retrospectively after a minimum follow-up of 2 years. The patients were divided into two groups according to the proximal fusion level: the T1 group (n=26) was fused to T1 and the T2 group (n=14) was fused to T2. Results : There were no significant differences in the preoperative curve characteristics between the two groups. In the T1 group, the preoperative upper curve magnitude of 38±7˚ and apical vertebral translation (AVT) of 8±6 mm were corrected to 17±7˚ (54% correction) and 4±3 mm (3 mm correction) at the final follow-up, respectively. In the T2 group, the preoperative upper curve magnitude of 37±5˚ and the AVT of 7±4 mm were corrected to 22±6˚ (42% correction) and 6±3 mm (1 mm correction) at the final follow-up, respectively. There was no difference in the correction of lower thoracic curve, sagittal alignment and balance between the two groups. There was a significantly better correction in the upper thoracic curve and T1 tilting in the T1 group than the the T2 group. Conclusion : In double thoracic AIS, fusions to T1 and T2 produce satisfactory results. However, fusion to T1 is recommended for a better correction of the upper curve and T1 tilting.

Purpose : To evaluate the results of a posterior procedure with segmental pedicle screw fixation in severe adolescent idiopathic scoliosis 70. Materials and Methods : Twenty-three adolescent idiopathic patients with a curve magnitude 70 subject to segmental pedicle screw fixation were analyzed retrospectively with a minimum follow-patients, except for 4 patients with King type I, were subjected to thoracic curve fusion. Twenty patients showed a thoracic curve 70 (70-96), and 4 patients had a lumbar curve 70 (70-77), preoperatively. The preoperative and postoperative standing roentgenograms were used to check the radiological parameters. Results : The mean preoperative thoracic curve was corrected from 79.59.1 to 25.35.8 at the most recent follow-up, showing a correction of 67.97.8% and loss of correction of 2.51.9%. The mean preoperative lumbar curve was corrected from 72.33.3 to 30.010.1 at the most recent follow-up (58.414.8% curve correction, 2.42.5% loss of curve correction). The mean preoperative lowest instrumented vertebral tilting was corrected from 30.07.4 to 10.55.6, showing a correction of 64.820.9%. The preoperative thoracic kyphosis improved from 28.311.2 (0-50) to 35.09.1 (22-53) postoperatively. There was neither pseudoarthrosis nor complications related to the pedicle screws at the most recent follow-up. Conclusion : Segmental pedicle screw fixation without an anterior release procedure in severe adolescent idiopathic scoliosis produced a satisfactory deformity correction with no significant loss of the curve correction. This procedure obviates the need for the anterior release and reduces the complications associated with anterior surgery.

‐ Abstract ‐ Study Design: This is a retrospective study. Objectives: We wanted to evaluate the outcomes of selective thoracic fusion with segmental pedicle screw fixation for treating thoracic idiopathic scoliosis with a minimum 5-year follow-up. Summary of the Literature Review: Segmental pedicle screw fixation has been proven to achieve true segmental control and greater correction of scoliosis in both the coronal and sagittal planes. However, there is no long-term study of selective thoracic fusion with segmental pedicle screw fixation for treating thoracic idiopathic scoliosis. Materials and Methods: We analyzed 203 thoracic idiopathic scoliosis patients (236 thoracic curves) who underwent selective thoracic fusion with segmental pedicle screw fixation. The mean patient age at the time of operation was 13.8 years (range: 8.9~18 years). Results: The preoperative thoracic curve of 51±12°was corrected to 16±7°(69% correction with 3% loss of correction) at the most recent follow-up. The non-instrumented lumbar curve of 30±10°was corrected to 10±8°(66% correction with 5% loss of correction) at the most recent follow-up. The preoperative thoracic kyphosis of 18±11°and the lumbar lordosis of 43±10° were improved to 23±8°and 46±9° , respectively, at the most recent follow-up. There was no junctional kyphosis at the most recent follow-up. Coronal decompensation at the most recent follow-up occurred in 10 patients. Postoperative adding-on occurred in 17 patients who were fused two levels short of the neutral vertebra. Of the 2867 thoracic pedicle screws inserted at the thoracic level, 43 screws were found to be malpositioned (1.5%), but they did not cause neurologic complications or adversely affect the long-term results. Conclusions: Selective thoracic fusion with segmental pedicle screw fixation for treating thoracic idiopathic scoliosis had satisfactory radiographic and clinical outcomes after surgery, and the outcomes were well-maintained for a minimum of 5 years follow-up. It is a safe and effective method for preserving segments of lumbar motion as well as for the restoration and maintenance of both the coronal and sagittal alignments.

Study Design: A retrospective cross-sectional study Objectives: To analyze the prevalence and characteristics of lumbar scoliosis using plain abdominal X-rays, according to age. Literature Review Summary: The single lumbar curves of adolescents have shown 10∼20% idiopathic scoliosis, but the reported prevalence of adult lumbar scoliosis ranges from 2.5 to 7.5%. In Korea, there is no useful basic data concerning lumbar scoliosis. Materials and Methods: A total of 2877 plain abdominal radiographies (supine and erect), taken at our hospital, between August 2001 and June 2002, were retrospectively investigated. The ages of the patients ranged from 11 to 80 years, and the patients were grouped according to age. The prevalence, Cobb angle, ratio of males and females, ratio of right and left curves, location of end and apex vertebra, the number of involved vertebra in primary curve, amount of rotation and osteophytes were all examined. Results: The overall prevalence of lumbar scoliosis was 4.3% (N=124), but rapidly increased after the sixth decade. The average Cobb angle was 16.2。. A positive correlation was found between the Cobb angle and age (r=0.275, P