Minimum 20 Years Long-term Clinical Outcome After Spinal Fusion and Instrumentation for Scoliosis: Comparison of the SRS-22 Patient Questionnaire With That in Nonscoliosis Group.

STUDY DESIGN: A retrospective minimum 20-year follow-up study using 4 standard self-administered questionnaires, one of which, the SRS-22 was also administered to control groups. OBJECTIVE: To evaluate long-term postoperative pain and other clinical outcomes of scoliosis correction and fusion surgery with Harrington instrumentation using Moe square-ended rods for better preservation of sagittal alignment. SUMMARY OF BACKGROUND DATA: Only a few long-term outcome studies have used standardized and validated self-administered tools, and no studies have established SRS-22 control data within their own population. There is no previous minimum 20-year follow-up evaluation after correction surgery preserving thoracic kyphosis and lumbar lordosis. METHODS: Of 86 consecutive patients who underwent instrumentation surgery for scoliosis by a single surgeon, 61 patients participated using Japanese Orthopaedic Association, Roland-Morris Disability Questionnaire, Oswestry Disability Index, and Scoliosis Research Society (SRS-22) questionnaires and 51 patients were included in this study. Results were analyzed for pain and other clinical outcomes. A total of 771 hospital employees were sent SRS-22 questionnaires. A total of 763 responded, resulting in 2 control groups composed of nonscoliosis and untreated mild scoliosis controls of the same culture and language as the long-term follow-up group. RESULTS: The prevalence of continuous low back pain was about 15%. Average Japanese Orthopaedic Association, Oswestry Disability Index, and Roland-Morris Disability Questionnaire scores at follow-up were 25 points, 7.3%, and 1.6, respectively. The average SRS-22 scores were 4.2 (function), 4.3 (pain), 3.7 (self-image), and 3.9 (mental health) for the postoperative follow-up group compared with 4.5 (function), 4.3 (pain), 3.5 (self-image), and 3.5 (mental health) for the nonscoliosis controls. CONCLUSION: Improved preservation of normal sagittal alignment resulted in a prevalence of low back pain comparable with the age-matched general population. Moreover, SRS-22 results for self-image and mental health were positive compared with the controls, possibly reflecting the surgeon's emphases on mental health and management of patient expectations. LEVEL OF EVIDENCE: 4.

Significance of peak height velocity as a predictive factor for curve progression in patients with idiopathic scoliosis.

BACKGROUND: Much attention has been paid to peak height velocity (PHV) as a possible predictor of curve progression in patients with idiopathic scoliosis (IS). The aim of this study was to analyze the relationship between the magnitude of the Cobb angle at PHV and scoliosis progression, defined as having surgery prior to skeletal maturity in female patients with IS. METHODS: A retrospective review identified 56 skeletally immature female IS patients who were followed until maturity. The mean age and the mean pubertal status at the initial visit were 10 years and 24 months before menarche respectively, with a follow-up period of 5 years. They were divided into two groups: non-surgery group (NS) and surgery group (S), depending on their treatment method in use at the final follow-up visit. Surgery group was defined as an ultimately having surgery due to Cobb angle greater than 45 degrees prior to skeletal maturity regardless of conservative management. Height measurements were recorded at each visit; height velocity was calculated as the height change, in cm, divided by the time interval, in years. The PHV, chronological age at PHV (APHV), height at PHV (HPHV), and final height (FH) were determined for each group. In patients with Cobb angle greater than 30 degrees, the corrected height was calculated by Kono formula and corrected height velocity values were provided. The sensitivity, specificity, and area under the curve (AUC) of the receiver-operating -characteristic (ROC) analysis were calculated to predict spinal curve progression for various Cobb-angle cutoff values at PHV. RESULTS: The corrected PHV had a mean value of 8.5 and 8.9 cm/year in the NS-group and S-group, respectively. The APHV was 11.9 and 11 years, the corrected HPHV was 152.9, and 149.3 cm, and the corrected FH was 159.9 and 159.3 cm, respectively. When a Cobb angle of 31.5 degrees was at PHV, ROC analysis revealed 78% sensitivity, 82% specificity, and an AUC of 0.93, acceptable values for curve progression in patients with IS. CONCLUSIONS: These findings indicate that 31.5 degrees of spinal curvature when patients are at PHV is a significant predictive indicator for progression of the curve to a magnitude requiring surgery. We suggest that the curve-progression risk assessment in patients with IS should include PHV, along with measures of skeletal and non-skeletal maturities.

Height velocity curves in female patients with idiopathic scoliosis.

Following identification of peak height velocity (PHV) by a recent study as a possible prognostic factor for curve progression in patients with idiopathic scoliosis (IS), the aim of this study was to investigate PHV curves in Japanese female patients with IS. The study subjects were 20 skeletally immature IS patients who were followed until maturity. The mean age and the mean pubertal status at the initial visit were 9.8 years and 24 months before menarche, respectively, with a follow-up period of 5.2 years. Height measurements were recorded at each visit, and HV was calculated as the change in height (cm) divided by the time interval (yr.) between visits of 6 to 12 months. The PHV, age at PHV (APHV), height at PHV (HPHV), and final height (FH) were determined. Patient HV curves were plotted using their HV data, and growth periods (GPs) were calculated from the curves. PHVs and GPs of study patients were compared to standard data from unaffected girls. The median values and interquartile ranges in PHV, APHV, HPHV, and FH were 8.5 cm/yr. (7.9-9.7), 11.8 yr. (11.2-12.1), 153.2 cm (150.1-155.8), and 160.1 cm (157.4-162.4), respectively. The median GP was 27 months. The PHV and GP values in IS female patients were higher and shorter than those in unaffected girls. These findings indicate that the patterns of height velocity curves in IS patients are different from those in unaffected girls, suggesting that curve progression in IS patients is associated with the magnitude of PHV and duration of GP. Recently, we have developed an HV reader to easily and quickly identify the present HV in patients with scoliosis, applicable for the clinical setting or school screening. We conclude that risk assessments of curve progression in patients with IS should include HV along with measures of skeletal maturity such as the Risser sign and/or digital skeletal age using hand X-rays.

Analysis of the Anterior Trunk Symmetry Index (ATSI). Preliminary report.

Spine deformations and faulty posture may be evaluated by assessing trunk surface deformation. POTSI index (Posterior Trunk Symmetry Index) was introduced in 2003 to assess asymmetry of the trunk seen from the back. However, deformations may also affect the anterior surface of the trunk and this can be noticed more easily by the patient owing to the visual accessibility of the anterior surface. This study a new parameter called ATSI (Anterior Trunk Symmetry Index) in order to assess the anterior trunk deformation. study was conducted on fifty primary school children, boys and girls aged 6-7 years. One photograph of each child in a spontaneous standing position was taken with a digital camera. The photographs were analysed to obtain a quantitative assessment of the new parameter, ATSI, by means of computer software developed in collaboration with an IT specialist. The intra-observer error found in the analysis was 1.23. The interobserver error was 3.08. The average ATSI value for 50 children was 25.3 ± 10.6. The threshold value norm defined as mean+2SD was 46.5.

A biomechanical study on the effects of rib head release on thoracic spinal motion.

PURPOSE: Idiopathic scoliosis is generally treated by surgical derotation of the spine. A secondary goal of surgery is minimization of the "rib hump" deformity. Previous studies have evaluated the effects of surgical releases such as diskectomy, costo-vertebral joint release, facetectomy, and costoplasty on spine mobilization and overall contribution to thoracic stability. The present study was designed to evaluate the biomechanical effects of the rib head joints alone on axial rotation, lateral bending, and segmental rotation, without diskectomy or disruption of anterior or posterior elements. METHODS: Four female cadaver thoracic spines with intact sternums and rib cages were mounted in an Instron servo-hydraulic bi-axial MTS. In a 12-step sequence, the costo-vertebral and costo-transverse ligaments were released, first unilaterally from T10-T7, then bilaterally until complete disarticulation between the rib heads and the vertebral bodies. After each release, biomechanical testing, including axial rotation and lateral bending, was performed. Vertebral body displacement was also measured using electromagnetic trackers. RESULTS: We found that rib displacement during axial rotation was significantly increased by unilateral rib head release, and torque was decreased with each successive cut. We also found increased vertebral displacement with sequential rib head release. CONCLUSIONS: Our results show that sequential costo-vertebral joint releases result in a decrease in the force required for axial rotation and lateral bending, coupled with an increase in the displacement of vertebral bodies. These findings suggest that surgical release of the costo-transverse and costo-vertebral ligaments can facilitate segmental correction in scoliosis by decreasing the torso's natural biomechanical resistance to this correction.

Super Hybrid Method of scoliosis correction: minimum 2-year follow-up.

We applied a new surgical technique utilizing conventional hybrid instrumentation to achieve better correction of trunk deformity in adolescent idiopathic scoliosis. The purpose of this study is to introduce our "Super Hybrid Method" and to analyze the results at minimum 2-year follow-up. The technique consists of rib mobilization (2006), a rod rotation maneuver (1997) and a hook rotation maneuver (2007). Forty-four idiopathic cases (female: 43) with minimum 2-year follow-up were reviewed (24-39 months, average 32). The average age at surgery was 20.4 years (12-57). The average pre-operative Cobb angle was 56.7 degrees (40-93). The average pre-operative rib hump was 23.2mm in height and 14.3 degrees by scoliometer. The average post-op Cobb angle was 13.3 degrees at 3 weeks and 18.1 degrees at follow-up. The average initial overall correction at 3 weeks post-op was 78% (83% for age<18, 73% for age < or =18) and 70% at later follow up (75% for age<18, 67% for age < or =18). The average rib hump 2 years post-operatively was 12.4mm in height and 7.3 degrees. Sixty nine percent of patients (18/26) with a pre-operative rib hump < or =20mm (20-49) had a decrease in hump height by more than 10mm (10-34). In Moiré analysis, the hump-sum measure (Suzuki) showed a statistically significant decrease from 13.4 preoperatively to 9.2 at 1 year post-op (p<0.001). Correction of deformity was excellent with our new technique. It is a less expensive procedure and carries little inherent risks.

Factors of thoracic cage deformity that affect pulmonary function in adolescent idiopathic thoracic scoliosis.

STUDY DESIGN: This clinical study examined the association between pulmonary function and thoracic cage deformities in scoliosis. OBJECTIVE: To determine the factors in spinal and thoracic cage deformities that affect pulmonary function in scoliosis. SUMMARY OF BACKGROUND DATA: Pulmonary function in scoliosis has generally been evaluated in terms of lateral spinal curvature. No previous report has evaluated changes in pulmonary function taking into consideration measurements reflecting not only spinal curvature but also thoracic cage deformities, although scoliosis is a three-dimensional deformity. METHODS: A total of 109 patients (mean age, 14.2 years) with adolescent idiopathic right thoracic scoliosis (mean lateral spinal curvature, 37.7 degrees) had full assessment of pulmonary function and a radiographic evaluation from radiographs of the whole spine, Moiré topography, and thoracic computed tomography. RESULTS: Multiple regression analysis (stepwise method) was performed at each vertebral level from T3-T12 to identify the factor that most strongly affects %VC. The correlation coefficient was highest at T9 and next highest at T8, with values of 0.641 (r2 = 0.411, P < 0.0001) and 0.625 (r2 = 0.390, P < 0.0001), respectively. At T9, multiple regression analysis showed that the sagittal diameter of the thoracic cage and the total lung area were identified as factors that most strongly affect %VC. Similarly, the sagittal diameter of the thoracic cage and the rotation angle to the sagittal plane were identified at T8. CONCLUSIONS: The factors that reduced %VC were the sagittal diameter of the thoracic cage, total lung area and vertebral rotation at the T8 and T9 levels.

Posterior circumferential decompression for late onset paraparesis caused by kyphotic deformity due to infantile tuberculosis--case report.

A 46-year-old male presented with late onset of paraparesis caused by kyphotic deformity due to infantile tuberculosis. A posterior circumferential decompression was performed from the sixth thoracic to the eighth thoracic levels. His neurological status improved with no evidence of kyphosis progression at the last follow up (2 years 5 months postoperatively). The paraparesis was caused by bony compression following increasing kyphosis above and below the block vertebrae due to growth. Posterior circumferential decompression is a less invasive surgical intervention for this condition.