Proximal Junctional Kyphosis in Adult Spinal Deformity: Definition, Classification, Risk Factors, and Prevention Strategies

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.

Adult Spinal Deformity: Current Concepts and Decision-Making Strategies for Management

Adult spinal deformity (ASD) is characterized by three-dimensional abnormalities of the thoracic or thoracolumbar spine that exerts significant impacts on the health-related quality of life (HRQoL). With the important effects that deformity of the sagittal plane exerts on the HRQoL, there have been paradigm shifts in ASD evaluation and management. Loss of lumbar lordosis is recognized as a key driver of ASD followed by reducing kyphosis, pelvic retroversion, and knee flexion. The Scoliosis Research Society (SRS)– Schwab classification reflects the sagittal spinopelvic parameters that correlate pain and disability in ASD patients. Although the SRS–Schwab classification provides a realignment target framework for surgeons, a structured patient-specific systemic approach is crucial for the process of decision-making. ASD management should be focused on restoring age-specific harmonious alignment and should consider the comorbidities and risk factors of each patient to prevent catastrophic complications and enhance the HRQoL.

Adult Spinal Deformity: Current Concepts and Decision-Making Strategies for Management

Adult spinal deformity (ASD) is characterized by three-dimensional abnormalities of the thoracic or thoracolumbar spine that exerts significant impacts on the health-related quality of life (HRQoL). With the important effects that deformity of the sagittal plane exerts on the HRQoL, there have been paradigm shifts in ASD evaluation and management. Loss of lumbar lordosis is recognized as a key driver of ASD followed by reducing kyphosis, pelvic retroversion, and knee flexion. The Scoliosis Research Society (SRS)– Schwab classification reflects the sagittal spinopelvic parameters that correlate pain and disability in ASD patients. Although the SRS–Schwab classification provides a realignment target framework for surgeons, a structured patient-specific systemic approach is crucial for the process of decision-making. ASD management should be focused on restoring age-specific harmonious alignment and should consider the comorbidities and risk factors of each patient to prevent catastrophic complications and enhance the HRQoL.

Prevalence of Thoracic Scoliosis in Koreans Using Simple Chest Radiography

OBJECTIVES@#To provide reference data for the study and treatment of thoracic scoliosis.SUMMARY OF LITERATURE REVIEW: There have been no reports on the prevalence of thoracic scoliosis in Korea.@*MATERIALS AND METHODS@#From August 2011 to October 2012, radiographs of patients under 80 years of age who underwent routine chest radiographs were retrospectively reviewed. Based on their age when the chest radiographs were obtained, the patients were divided into 8 groups. The prevalence and angle of the curve of thoracic scoliosis were investigated in each age group, and the prevalence of thoracic scoliosis according to sex, the direction of the curve, number of vertebrae in the major curve, the location and rotation of the apical vertebrae, and osteophyte location were examined.@*RESULTS@#The prevalence of thoracic scoliosis was 2.4% (621 patients), and female patients (3.0%, 375 of 12471) showed a higher prevalence than male patients (1.8%, 246 of 13654) (p<0.001). Right curvature was present in 445 patients and left curvature in 176 patients. In each age group, the prevalence and degree of thoracic scoliosis were 1.1% (14.2°±3.2°), 2.3% (17.4°±7.7°), 2.5% (17.0°±8.9°), 1.9% (15.8°±5.9°), 1.3% (15.5°±6.6°), 2.1% (18.0°±13.6°), 2.9% (14.3°±3.6°), and 6.1% (16.2°±4.8°), respectively. The mean curvature in all scoliosis patients was 16.0°±7.0°. The angle of the curve was significantly different by sex (15.4°±7.1° for males, 16.8°±7.6° for females). The average curve angle of patients with thoracic scoliosis was 16.0°±7.0°, among whom it was 10°–20° in 533 patients, 20°–30° in 64, 30°–40° in 11, and over 40° in 13.@*CONCLUSIONS@#This study could be used as a reference point for the study and treatment of thoracic scoliosis.

Prevalence of Thoracic Scoliosis in Koreans Using Simple Chest Radiography / 대한척추외과학회지

STUDY DESIGN: A cross-sectional study. OBJECTIVES: To provide reference data for the study and treatment of thoracic scoliosis. SUMMARY OF LITERATURE REVIEW: There have been no reports on the prevalence of thoracic scoliosis in Korea. MATERIALS AND METHODS: From August 2011 to October 2012, radiographs of patients under 80 years of age who underwent routine chest radiographs were retrospectively reviewed. Based on their age when the chest radiographs were obtained, the patients were divided into 8 groups. The prevalence and angle of the curve of thoracic scoliosis were investigated in each age group, and the prevalence of thoracic scoliosis according to sex, the direction of the curve, number of vertebrae in the major curve, the location and rotation of the apical vertebrae, and osteophyte location were examined. RESULTS: The prevalence of thoracic scoliosis was 2.4% (621 patients), and female patients (3.0%, 375 of 12471) showed a higher prevalence than male patients (1.8%, 246 of 13654) (p<0.001). Right curvature was present in 445 patients and left curvature in 176 patients. In each age group, the prevalence and degree of thoracic scoliosis were 1.1% (14.2°±3.2°), 2.3% (17.4°±7.7°), 2.5% (17.0°±8.9°), 1.9% (15.8°±5.9°), 1.3% (15.5°±6.6°), 2.1% (18.0°±13.6°), 2.9% (14.3°±3.6°), and 6.1% (16.2°±4.8°), respectively. The mean curvature in all scoliosis patients was 16.0°±7.0°. The angle of the curve was significantly different by sex (15.4°±7.1° for males, 16.8°±7.6° for females). The average curve angle of patients with thoracic scoliosis was 16.0°±7.0°, among whom it was 10°–20° in 533 patients, 20°–30° in 64, 30°–40° in 11, and over 40° in 13. CONCLUSIONS: This study could be used as a reference point for the study and treatment of thoracic scoliosis.

Effect of Direct Vertebral Rotation on the Uninstrumented Lumbar Curve in Thoracic Adolescent Idiopathic Scoliosis

STUDY DESIGN: Retrospective study. PURPOSE: To determine the effect and direction of direct vertebral rotation (DVR) in the lowest instrumented vertebra (LIV) on the uninstrumented lumbar curve depending on the lumbar modifier used for the correction of thoracic adolescent idiopathic scoliosis. OVERVIEW OF LITERATURE: DVR in the LIV should be implemented in a different direction to obtain better spontaneous lumbar correction depending on the preoperative lumbar spine modifier. METHODS: We retrospectively analyzed 160 patients with thoracic adolescent idiopathic scoliosis treated by pedicle screw instrumentation and rod derotation. Patients who had a distal fusion level between T11 and L1 were divided into two groups: the DVR group versus the No-DVR group. Each group was divided into subgroups depending on the lumbar modifier used: the DVR-A, B, and C groups versus the No-DVR-A, B, and C groups. The DVR-A group was subdivided into two subgroups depending on the direction of screw rotation in the LIV: the DVR-A-O group (opposite direction) and the DVR-A-S group (same direction). RESULTS: There were no significant differences in the preoperative curve characteristics between the two groups. The preoperative lumbar curve was corrected in 70% of the patients in the DVR group and in 56% in the No-DVR group. Spontaneous coronal correction of the lumbar curve was better in the DVR-A-S group than that in the No-DVR-A group. However, the DVR-A-O group had the higher incidence of adding-on deformity. The DVR-B and C groups showed better spontaneous correction of lumbar coronal magnitude, apical vertebral translation, and rotation and the LIV tilting. CONCLUSIONS: In lumbar modifiers B and C, screws in the LIV have to be rotated opposite to the direction of the screw rotation of the main thoracic curve; however, in modifier A, the screws have to be rotated in the same direction.

Medication Persistence for Osteoporosis and Its Related Factor in Patients with Osteoporotic Compression Vertebral Fracture / 대한골다공증학회지

INTRODUCTION: Osteoporotic vertebral fractures, which account for the largest part of the disease has become important and common diseases. We studied persistence for osteoporosis medication and its related factor in patients with osteoporotic compression vertebral fracture. METHODS: A total of 458 patients that visited our outpatient clinic with osteoporotic vertebral fractures and were prescribed with osteoporosis medication at the Seoul Spine Center from January 2010 to February 2014 and were analyzed retrospectively. The male to female ratio was 403: 55 and the mean age was 75 years. Survival analysis was used with the Kaplan-Meier method. Related factor analysis was performed with the log rank test and Cox regression test. RESULTS: The survival rate at 6 months was 52%, 12 months was 40%, 24 months was 28%, and at 3 years it was 25%. There was no difference between the persistent rate according to age. Women demonstrated higher persistent rate than men in significantly. It showed a significant difference between some of the groups in accordance with the dose rate and duration of the drug dose interval. Especially, medication change group had significant higher persistence rate than not changing group. CONCLUSIONS: Persistence rate of osteoporosis drugs, decreased rapidly with the passage of time. The patients with changing medication during follow-up had significantly higher persistence ratio than those without it. The persistence rate of osteoporosis medication could be increased through actively solving the problems of the patients, which are associated with taking medication.

Determination of the Distal Fusion Level in the Management of Thoracolumbar and Lumbar Adolescent Idiopathic Scoliosis Using Pedicle Screw Instrumentation

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 10degrees 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.

Surgical Treatment of Adult Degenerative Scoliosis

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.

Specific Sagittal Curve Patterns of Cervical Spine in Adolescent Idiopathic Scoliosis (AIS)

STUDY DESIGN: A retrospective study. OBJECTIVES: To evaluate the sagittal alignment of cervical spine in AIS. SUMMARY OF LITERATURE REVIEW: Little has been known about the sagittal curve patterns of cervical spine in AIS patients. MATERIALS AND METHODS: One-hundred-thirty-three AIS patients were checked by scanographs and followed up for more than 2 years were divided into cervical kyphosis (> or =+5degrees), lordosis (< or =-5degrees) and straight (-4degrees~+4degrees) groups according to the sagittal curves of cervical spine (C2~C7). Each group was evaluated for thoracic kyphosis, lumbar lordosis, sagittal balance and Cobb's angle on coronal plane. Of the patients, 49 were treated by braces, 84 were surgically corrected (rod derotation in 52, direct vertebral rotation (DVR) in 32). RESULTS: At the initial radiographs, cervical kyphosis was found in 97, lordosis in 23 and straight in 13 patients. In the kyphosis group, cervical kyphosis showed typical patterns of angular kyphosis. Thoracic and upper T-kyphosis (T1~T5) were lower than those in the cervical lordosis group (p=0.000, 0.001, respectively.) Other factors showed no significant differences between the groups. Patients treated by conservative management or by rod derotation had no significant differences in cervical kyphosis during the follow-up periods, though the thoracic hypokyphosis was surgically corrected. On the contrary, patients who were treated by DVR restored cervical lordosis (14/32=43.8%) from initial state showed significant differences in both conservative and rod derotation groups (p=0.008, 0.002, respectively). CONCLUSIONS: Cervical kyphosis in AIS was a compensatory curve correlated with both thoracic hypokyphosis and rotational deformity. Rotational corrections should be considered during the surgical treatment.

Complications of Posterior Vertebral Resection for Spinal Deformity

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 51.4degrees to 2.7degrees, thoracic scoliosis 63.9degrees to 24.5degrees (62.6% correction), and thoracolumbar or lumbar scoliosis 50.1degrees to 17.1degrees (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). 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.

Pedicle Screw Instrumentation for Adolescent Idiopathic Scoliosis: The Insertion Technique, the Fusion Levels and Direct Vertebral Rotation

The pedicle is a power nucleus of the vertebra and offers a secure grip of all 3 columns. Pedicle screw instrumentation has advantages of rigid fixation with improved three-dimensional (3D) correction and it is accepted as a reliable method with a high margin of safety. Accurate placement of the pedicle screws is important to reduce possible irreversible complications. Many methods of screw insertion have been reported. The author has been using the K-wire method coupled with the intraoperative single posteroanterior and lateral radiographs, which is the most safe, accurate and fast method. Identification of the curve patterns and determining the fusion levels are very important. The ideal classification of adolescent idiopathic scoliosis should address the all patterns, predict the extent of accurate fusion and have good inter/intraobserver reliability. My classification system matches with the ideal classification system, and it is simple and easy to learn; and my classification system has only 4 structural curve patterns and each curve has 2 types. Scoliosis is a 3D deformity; the coronal and sagittal curves can be corrected with rod rotation, and rotational deformity has to be corrected with direct vertebral rotation (DVR). Rod derotation and DVR are true methods of 3D deformity correction with shorter fusion and improved correction of both the fused and unfused curves, and this is accomplished using pedicle screw fixation. The direction of DVR is very important and it should be opposite to the direction of the rotational deformity of the vertebra. A rigid rod has to be used to prevent rod bend-out during the derotation and DVR.

Analysis of Intraoperative Neurological Complications in High-Risk Spinal Surgery with the Use of Motor Evoked Potential Monitoring

STUDY DESIGN: This is retrospective study. OBJECTIVES: To evaluate the risk of operative techniques using Motor Evoked Potential (MEP) in high-risk spinal surgery. SUMMARY OF LITERATURE REVIEW: There are few studies regarding the evaluation of operative techniques by MEP. MATERIALS AND METHODS: We studied 33 cases that had MEP during surgery from July 2007 to March 2009. Diagnoses included post-traumatic kyphosis (PTK) in eight cases, congenital deformity in eight cases, degenerative lumbar deformity in eight cases, ankylosing spondylitis (AS) in three cases, spinal tumor in three cases, adjacent segmental disease in two cases, and post-surgical kyphosis in one case. Posterior vertebral column resection (PVCR) and pedicle subtraction osteotomy (PSO) were performed in 27 cases (81.8%) and, in the others, posterior decompression with discectomy was performed. We analyzed the risk of operative techniques and evaluated the MEP. RESULTS: MEP showed abnormal signal change in five cases (PVCR: one case, compression and distraction: four cases). The AS case did not demonstrate neurological change after surgery. Though the PTK on T12 operated by PVCR case did not show an abnormal MEP result, neurological change was observed postoperatively. The sensitivity, specificity, percent of false negatives, and percent of false positives of MEP were 80.0%, 96.4%, 20.0%, and 3.6%, respectively. CONCLUSIONS: MEP monitoring is a useful method to detect neurological injury during high-risk spinal surgery with satisfactory specificity. For low sensitivity and a high false negative rate, increased monitoring of cases and continuous follow-up is needed. In conclusion, compression and distraction and PVCR are high-risk techniques in kyphotic deformity correction.

The Revision Operation Rate for Adjacent Segmental Degeneration by Survival Analysis in Mono-segment Lumbar Fusion / 대한정형외과학회잡지

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 survival 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 BMI> or =25 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.

A Comparison of Clinical Stability of Distal Instrument Fused Down to S1 with and without Sub-S1 Alar Screw in the Long Fusion using Segmental Pedicle Screw for Lumbar Degenerative Deformity

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 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 (P0.05). 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.

Proximal Adjacent Segment Disease following Posterior Instrumentation and Fusion for Degenerative Lumbar Scoliosis / 대한정형외과학회잡지

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.

Cervical and Thoracic Sagittal Curves in Thoracic Adolescent Idiopathic Scoliosis / 대한척추외과학회지

STUDY DESIGN: Prospective study OBJECTIVES: To analyze and compare the cervical and thoracic sagittal curves between normal adolescents and patients with thoracic adolescent idiopathic scoliosis (AIS). SUMMARY OF THE LITERATURE REVIEW: There are no reports on cervical sagittal curves and its correlation with thoracic sagittal curves in AIS. MATERIALS AND 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 > or = 45degrees. 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+/-14.6degrees in the cervical spine radiographs and -0.6+/-12.9degrees ('-' means kyphosis) in whole spine radiographs. In the AIS group, cervical lordosis was -5.0+/-12.9degrees in the cervical radiographs and -8.1+/-12.7degrees 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+/-10.6degrees and 38.9+/-13.1degrees in the N-adol group, respectively, and 17.8+/-9.4degrees and 30.1+/-11.8degrees in the AIS group, respectively. There was a significant difference between the two groups (Ps0.05). 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.

Posterior Hemivertebra Excision in Congenital Scoliosis / 대한척추외과학회지

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+/-12degrees was corrected to a mean of 17+/-10degrees (65% correction), and mean preoperative kyphosis of 46+/-18degrees was corrected to a mean of 12+/-12degrees at the most recent follow-up. The compensatory curve had a mean of 25+/-10degrees preoperatively and spontaneously corrected to a mean of 8+/-8degrees (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.

Correction of Double Thoracic Adolescent Idiopathic Scoliosis Using PedicleScrew Instrumentation: Comparison with Translation and Rod Derotation / 대한정형외과학회잡지

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 degrees improved to 24+/-4 degrees (35% correction), and the lower thoracic curve of 52+/-9 degrees improved to 18+/-5 degrees (65% correction). In the RD group, the preoperative upper thoracic curve of 40+/-7 degrees improved to 19+/-7 degrees (51% correction), and the lower thoracic curve of 56+/-12 degrees was improved to 16+/-6 degrees (72% correction). The correction of the upper and lower thoracic curves was significantly better in the RD group (p<0.05). Thoracic sagittal kyphosis was corrected from 21 degrees to 24 degrees in the TR group and from 18 degrees to 26 degrees in the RD group. There was no significant difference in the spinal balance, shoulder height difference, T1 tilt and fusion extent. The operating time and the amount of blood loss was 231 minutes and 2050ml in the TR group and 263 minutes and 3217ml in the RD group, respectively (p<0.05). CONCLUSION: In correcting double thoracic AIS using pedicle screw instrumentation, the rod derotation method showed better correction for the upper and lower thoracic curves. The translation method showed the advantages of easier application, a shorter operation time and less blood loss.

Comparison of Short Fusion versus Long Fusion for Degenerative Lumbar Scoliosis / 대한정형외과학회잡지

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 16.3 degrees in the short fusion group and 22 degrees in the long fusion group, which changed to 10.1 degrees and 8.47 degrees, 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.