The Prevalence of Scoliosis after Fontan Circulation Surgery Followed-Up to Adolescence.

Introduction: The advancement of surgical techniques and perioperative management for congenital heart disease (CHD) has increased life expectancy. The surgical creation of the Fontan circulation maintains pulmonary blood flow without relying on an effective pump from the abnormal heart, relying on peripheral vascular resistance to maintain effective flow through the lungs. Unfortunately, this delicate mechanism is compromised when scoliosis restricts ventilation, leading to Fontan failure and a poor prognosis for life. This report describes the prevalence of scoliosis with Fontan completion surgery and the role of screening and surgical correction. Methods: Ninety-six consecutive Japanese patients undergoing Fontan completion surgery for CHD between 2000 and 2017 were identified in our institutional records. The inclusion criterion was at least 7 years of follow-up after Fontan completion surgery, while the exclusion criteria were congenital, syndromic, and neuromuscular scoliosis. Radiographic and clinical parameters, including cardio-thoracic ratio (CTR) for cardiomegaly and cyanosis saturation, were compared between with and without scoliosis. Results: There were 23 and 40 patients in the scoliosis and no scoliosis groups, respectively. The mean age at the final follow-up was 18.5 and 16.7 years in the scoliosis and no scoliosis groups, respectively (p=0.02). Mean CTR was 43.7% and 39.4% in the scoliosis and no scoliosis groups (p=0.016), and the mean saturation in room air at the final follow-up was 88.8% and 93.2%, respectively (p=0.036). There were no significant differences to clarify the risk factors with multivariate logistic regression analysis. Conclusions: The prevalence of scoliosis with Fontan completion surgery was 36.5%. Screening for scoliosis is important for children with Fontan circulation surgery as part of their routine follow-up at least until they reach adolescence.Evidence Level: 4.

Evaluation of Trabecular Microstructure of Cancellous Bone Using Quarter-Detector Computed Tomography.

Quarter-detector computed tomography (QDCT) is an ultra-high-spatial-resolution imaging technique. This study aimed to verify the validity of trabecular structure evaluation using a QDCT scanner in the diagnosis of osteoporosis. We used a cancellous bone specimen image of the second lumbar vertebrae of an adult male with moderate osteoporosis. To obtain QDCT images, we created a three-dimensional model from micro-CT images of the specimen. Statistical analysis was performed on the relationship between micro-CT and QDCT imaging modalities. The differences between micro-CT and QDCT were assessed based on their significance with respect to the calculated mean measurements using the Mann-Whitney test. Single regression analysis was performed using linear regression, with micro-CT and QDCT as the explanatory and objective variables, respectively, to determine the relationship of the measured values between the two modalities. By applying the necessary correction to the micro-CT measured values, it is possible to perform an analysis equivalent to micro-CT, which offers higher spatial resolution than QDCT. We found evidence that if QDCT can be used, trabecular structure evaluation may contribute to image diagnosis to evaluate practical bone fragility.

Costello syndrome-associated orthopaedic manifestations focussed on kyphoscoliosis: a case series describing the natural course.

Costello syndrome (CS) is a rare genetic condition caused by a heterozygous mutation in the HRAS gene, with an estimated prevalence of 1: 300 000. Individuals with CS present with characteristic features including scoliosis, kyphosis, Chiari 1 malformation, and syringomyelia. The natural history of the spinal deformity associated with CS has been incompletely described. This case series describes the spinal deformity associated with CS and sets out a strategy for screening and treatment. The clinical records and spinal radiographs of nine consecutive CS patients encountered at a single centre were reviewed. Radiological assessments for the presence and progression of scoliosis were studied. Nine patients with confirmed CS were followed for a mean of 6.6 years. Five patients showed mild scoliosis. Two patients had lumbar kyphosis in addition to their scoliosis, and one showed scoliosis with proximal thoracic kyphosis. Three patients underwent investigation with MRI, one of which showed Chiari I malformation and a syrinx. One showed no change in the severity of their deformity over time. The remaining four patients showed a rate of increasing coronal deformity of 2.1° per year. There were no cases of rapid progression. All cases showed delayed skeletal maturity. The spinal deformity in CS appears to be slowly progressive. To identify those at risk of more rapid progression, brain and spine MRI should be carried out to exclude structural neurological abnormalities. Long follow-up is required for patients with spinal deformity in CS due to the delay in reaching skeletal maturity. Evidence level: 4.

The Association of Scoliosis and NSD1 Gene Deletion in Sotos Syndrome Patients.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: The aim of this study was to examine the NSD1 abnormalities in patients diagnosed with Sotos syndrome and its correlation with the presence, severity, and progression of associated scoliosis. SUMMARY OF BACKGROUND DATA: Scoliosis has been reported in approximately 30% of patients diagnosed with Sotos syndrome, a genetic disorder characterized by a distinctive facial appearance, learning disability, and overgrowth. Sotos syndrome is mainly attributed to NSD1 haploinsufficiency, but with ethnical differences in genetic profile: NSD1 microdeletions are frequently identified in Japanese Sotos patients whereas intragenic mutations are more frequently found in non-Japanese patients. Although possible genotype-phenotype correlations have been proposed, the genotype of Sotos syndrome patients suffering from scoliosis has not been examined. METHODS: The medical records and spinal radiographs of 63 consecutive Sotos syndrome patients at a single center were reviewed. Fluorescent in situ hybridization or microarray comparative genomic hybridization and DNA sequencing or multiplex ligation-dependent probe amplification were performed to detect 5q35 microdeletion involving the NSD1 gene and intragenic mutations of the NSD1 gene, respectively. The phenotypes of all cases and radiological assessments for the presence and progression of scoliosis were studied. RESULTS: NSD1 abnormalities were identified in 55 patients (87%): microdeletion in 34 patients (54%) and intragenic mutation in 22 patients (33%). Scoliosis was observed in 26 patients (41%), with a significantly higher ratio of microdeletions than mutations. The 10 patients with progressive scoliosis all had NSD1 microdeletions. CONCLUSION: Scoliosis was a common phenotypical trait in children with Sotos syndrome and its presence as well as progression were higher in cases with NSD1 microdeletions. Although all Sotos syndrome patients should be monitored for scoliosis, clinicians should be made aware that patients with NSD1 microdeletions have a higher probability of scoliosis development and progression that may require early intervention.Level of Evidence: 3.

Does corrective spine surgery improve the standing balance in patients with adult spinal deformity?

BACKGROUND CONTEXT: The effect of corrective spine surgery on standing stability in adult spinal deformity (ASD) has not been fully documented. PURPOSE: To compare pre- and postoperative standing balance and posture in patients with ASD. STUDY DESIGN/SETTING: This study is a prospective case series. PATIENT SAMPLE: Standing balance before and after corrective spine surgery was compared in 35 consecutive female patients with ASD (65.6±6.9 years, body mass index 22.3±2.7 kg/m2, Cobb angle 50.2±19.2°, C7 plumb line 9.3±5.6 cm, and pelvic incidence-lumbar lordosis mismatch 40.8±23.3°). OUTCOME MEASURES: The Scoliosis Research Society Patient Questionnaire, the Oswestry Disability Index, and force-plate analysis were used to evaluate the patient outcomes. MATERIALS AND METHODS: We reviewed patient charts and X-rays and compared standing balance before and after corrective spine surgery. All subjects were assessed by force-plate analysis using optical markers while standing naturally on a custom-built force platform. The spinal tilt, pelvic obliquity, pelvic tilt, and joint angle were calculated. The lower leg lean volume was obtained by whole-body dual X-ray absorptiometry to assess muscle strength. RESULTS: ASD patients showed significant differences between the left and right sides in ground reaction force (dGRFs), hip (dHip), and knee angle (dKnee) while standing (dGRF 15.1±8.7%, dHip 7.1±6.6°, dKnee 5.9±5.5°). The recorded center-of-gravity (CoG) area was not improved after surgery, whereas the dGRF, dHip, and dKnee all decreased. The spinal tilt, pelvic obliquity, and pelvic tilt were all significantly improved after surgery. We found significant correlations between the radiographic trunk shift and the postoperative coronal CoG distance and recorded CoG area, and between the sagittal CoG distance and the age and the lean volume of the lower extremities (trunk shift R=0.33, 0.45; age R=0.32; lean volume R=0.31). CONCLUSIONS: Corrective spinal surgery improved the spinal alignment and joint angles in patients with ASD but did not improve the standing stability. A correlation found between the sagittal CoG distance and the lean volume of the lower extremities indicated the importance of the leg muscles for stability when standing, whereas a correlation found between the coronal CoG distance and trunk shift reflected the attenuated postural response in the ASD patients.

Onset and remodeling of coronal imbalance after selective posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis (a pilot study).

BACKGROUND: Postoperative coronal imbalance is a significant problem after selective thoracic fusion for primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). However, longitudinal studies on postoperative behavior of coronal balance are lacking. This multicenter retrospective study was conducted to analyze factors related to onset and remodeling of postoperative coronal imbalance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-one Lenke 1C or 2C AIS patients, who underwent posterior thoracic fusion ending at L3 or above, were included with a minimum 2-year follow-up. The mean patients' age was 15.1 years at the time of surgery. Radiographic measurements were performed on Cobb angles of the main thoracic (MT) and thoracolumbar/lumbar (TLL) curves and coronal balance. Factors related to the onset of immediately postoperative coronal decompensation (IPCD) and postoperative coronal balance remodeling (PCBR), defined as an improvement of coronal balance during postoperative follow-up, were investigated using comparative and correlation analyses. RESULTS: Mean Cobb angles for the MT and TLL curves were 57.3° and 42.3° preoperatively and were corrected to 22.8° and 22.5° at final follow-up, respectively. Mean preoperative coronal balance of -3.8 mm got worse to -21.2 mm postoperatively, and regained to -12.0 mm at final follow-up. Coronal decompensation was observed in two patients preoperatively, in ten patients immediately postoperatively, and in three patients at final follow-up. The preoperative coronal balance and lowest instrumented vertebra (LIV) selection relative to stable vertebra (SV) were significantly different between patients with IPCD and those without. PCBR had significantly negative correlation with immediately postoperative coronal balance. CONCLUSIONS: IPCD after posterior thoracic fusion for Lenke 1C and 2C AIS was frequent and associated with preoperative coronal balance and LIV selection. However, most patients with IPCD regained coronal balance through PCBR, which was significantly associated with immediately postoperative coronal balance. A fixation more distal to SV shifted the coronal balance further to the left postoperatively.

Walking balance and compensatory gait mechanisms in surgically treated patients with adult spinal deformity.

BACKGROUND CONTEXT: Gait patterns and their relationship to demographic and radiographic data in patients with adult spinal deformity (ASD) have not been fully documented. PURPOSE: This study aimed to assess gait pattern in patients with ASD and the effect of corrective spinal surgery on gait. DESIGN/SETTING: This is a prospective case series. PATIENT SAMPLE: The gait patterns of 33 consecutive women with ASD (age 67.1 years; body mass index [BMI] 22.5±2.5 kg/m2, Cobb angle 46.8±18.2°, coronal vertical axis [CVA] 1.5±3.7 cm, C7 sagittal vertical axis [SVA] 9.1±6.4 cm, pelvic incidence minus lumbar lordosis [PI-LL] 38.2±22.1°, and lean volume of the lower leg, 5.5±0.6 kg) before and after corrective surgery were compared with those of 33 age- and gender-matched healthy volunteers. OUTCOME MEASURES: Scoliosis Research Society Patient Questionnaire (SRS22r), Oswestry Disability Index (ODI), and forceplate analysis. METHODS: All subjects underwent gait analysis on a custom-built forceplate using optical markers placed on all joints and spinal processes. Dual X-ray absorptiometry scores were used to calculate the lean composition of the lower legs. Subjects with ASD were followed for at least 2 years post operation. RESULTS: Preop mean values showed that patients with ASD had a significantly worse gait velocity (54±10 m/min vs. 70.7±12.9 m/min, p<.01) and stride (97.8±13.4 cm vs. 115.3±15.1 cm, p<.01), but no difference was observed in the stance-to-swing ratio. The right and left ground reaction force vectors were also discordant in the ASD group (vertical direction; r=0.84 vs. r=.97, p=.01). The hip range of motion (ROM) was also significantly decreased in ASD. Correlation coefficient showed moderate correlations between the preoperative gait velocity and the gravity line (GL), PI, ROM of the lower extremity joints, and lean volume, and between the stride and the lean volume, GL, and PI-LL. Gait pattern, stride, and velocity all improved significantly in the patients with ASD after surgery, but were still not as good as in healthy volunteers. The SRS22r satisfaction domain correlated moderately with postoperative gait velocity (r=0.34). CONCLUSIONS: The patients with ASD had an asymmetric gait pattern and impaired gait ability compared with healthy volunteers. Gait ability correlated significantly with the GL, spinopelvic alignment, lower extremity joint ROM, and lean volume. The surgical correction of spinopelvic alignment and exercises to build muscle strength may improve the gait pattern and ability in patients with ASD.

Walking sagittal balance correction by pedicle subtraction osteotomy in adults with fixed sagittal imbalance.

PURPOSE: Pedicle subtraction osteotomy (PSO) is widely used to treat severe fixed sagittal imbalance. However, the effect of PSO on balance has not been fully documented. The aim of this study was to assess dynamic walking balance after PSO to treat fixed sagittal imbalance. METHODS: Gait and balance were assessed in 15 consecutive adult female patients who had been treated by PSO for a fixed sagittal imbalance and compare patients' preop and postop dynamic walking balance with that of 15 age- and gender-matched healthy volunteers (HV). Each patient's chart, X-rays, pre and postop SRS22 outcome scores, and ODI were reviewed. Means were compared by Mann-Whitney U test and Chi-square test. RESULTS: The mean age was 66.3 years (51-74 years). The mean follow-up was 2.7 years (2-3.5 years). The C7PL and GL, measured on the force platform, were both improved from 24.2 ± 7.3 cm and 27.6 ± 9.4 to 5.4 ± 2.6 cm and 7.2 ± 3.4 cm, respectively. The baseline hip ROM was significantly smaller in patients compared to HV, whereas no significant difference was observed in the knee or ankle ROM. The pelvic tilt (preop -0.4° ± 1.4°, postop 8.9° ± 1.0°), and maximum hip-extension angle (preop -1.2° ± 14.2°, postop -11.2° ± 7.2°) were also improved after surgery. Cadence (116 s/min), stance-swing ratio (stance 63.2 % vs. swing 36.8 %), and stride (98.0 cm) were all increased after surgery. On the other hand, gait velocity was significantly slower in the PSO group at both pre and postop than in HV (PSO 53.3 m/min at preop and 58.8 m/min at postop vs. HV 71.1 m/min, p = 0.04). CONCLUSIONS: Despite a mild residual spinal-pelvic malalignment, PSO restored sagittal alignment and balance satisfactorily and has improved the gait pattern.

Anterior spinal fixation for recollapse of cemented vertebrae after percutaneous vertebroplasty.

Although recollapse after percutaneous vertebroplasty (PV) is a serious complication that needs salvage surgery, there is no consensus regarding the best operative treatment for this failure. We present cases of 3 patients, diagnosed as having thoracic osteoporotic vertebral fractures, who had undergone PV at other institutes. Within less than half a year, recollapse occurred at the cemented vertebrae in all 3 patients, and we conducted anterior spinal fixation (ASF) on them. In all cases, ASF relieved the patient's severe low back pain, and there was no recurrence of symptoms during the follow-up period of 6 years, on average. ASF is the optimal salvage procedure, since it allows for the direct decompression of nerve tissue with reconstruction of the collapsed spinal column, and preservation of the ligaments and muscles that stabilise the posterior spine. Surgeons who perform PV need to be able to assess this failure early and to perform spinal fixation.

Atlantoaxial Subluxation after Pyogenic Spondylitis around the Odontoid Process.

Study Design. A case report and review of the literature. Objective. The aim of this study was to describe the conservative management of pyogenic spondylitis around the odontoid process. Summary of Background Data. Atlantoaxial subluxation after pyogenic spondylitis is rare. The therapeutic approach to infection of the upper cervical spine is controversial. Methods. Medical chart and radiological images of a 76-year-old male patient were retrospectively reviewed. Radiography revealed atlantoaxial subluxation, and an abscess was seen around the odontoid process on magnetic resonance images. Intravenous antibiotics and a halo vest were used to treat the patient. We then observed the patient's conservative treatment course. Results. C-reactive protein levels returned to normal 4 weeks after administration of the intravenous antibiotics. The patient's muscle weakness also completely recovered 8 weeks after administration of the intravenous antibiotics. Because the patient was able to walk without any support, surgical treatment was not necessary. Conclusions. Pyogenic spondylitis of the upper cervical spine is a rare manifestation. Surgical or conservative treatment must be selected carefully based on the patient's symptoms. If early diagnosis and treatment can be provided to the patients, conservative treatment can be achieved.

Reoperation rate and risk factors of elective spinal surgery for degenerative spondylolisthesis: minimum 5-year follow-up.

BACKGROUND CONTEXT: The favorable outcome of surgical treatment for degenerative lumbar spondylolisthesis (DS) is widely recognized, but some patients require reoperation because of complications, such as pseudoarthrosis, persistent pain, infection, and progressive degenerative changes. Among these changes, adjacent segmental disease (ASD) and same segmental disease (SSD) are common reasons for reoperation. However, the relative risks of the various factors and their interactions are unclear. PURPOSE: The purpose of this study was to determine the longitudinal reoperation rate after surgery for DS and to assess the incidence and independent risk factors for ASD and SSD. STUDY DESIGN: This study is a retrospective consecutive case series of patients with DS who were surgically treated. PATIENT SAMPLE: We assessed 163 consecutive patients who were surgically treated for DS between 2003 and 2008. Individual patients were followed for at least 5 years after the initial surgery. OUTCOME MEASURES: The primary end point was any type of second lumbar surgery. Radiographic measurements and demographic data were reviewed. We compared patients who underwent reoperation with those who did not. Logistic regression analysis was used to determine the relative risk of ASD and SSD in patients surgically treated for DS. METHODS: Radiographic measurements and demographic data were reviewed. We identified the incidence and risk factors for reoperation, and we performed univariate and multivariate analyses to determine the independent risk factors for revision surgery for SSD and for ASD as the two distinct reasons for the reoperation. Age, gender, etiology, body mass index (BMI), and other radiographic data were analyzed to determine the risk factors for developing SSD and ASD. RESULTS: The average patient age was 65.8 (50-81 years; 73 women and 90 men; mean follow-up, 5.9±1.6 years). Eighty-nine patients had posterior lumbar interbody fusion and 74 had laminotomies. Twenty-two patients had L3-L4 involvement and 141 had L4-L5 involvement. The cumulative reoperation rate was 6.1% at 1 year, 8.5% at 2 years, 15.2% at 3 years, 17.7% at 5 years, and 23.3% (38/163 patients) at the final follow-up. A significantly higher reoperation rate was observed for patients undergoing laminotomy than for patients undergoing posterior lumbar interbody fusion (33.8% vs. 14.4%, p=.01). Eighteen patients (11.0%) had SSD, and 13 patients (8.9%) developed ASD. Higher BMI (obesity) and greater disc height (greater than 10 mm) predicted the occurrence of SSD in the multivariate model (BMI=odds ratio 4.11 [95% confidence interval 1.29-13.11], p=.016; disc height=3.18 [1.03-9.82], p=.044), and gender (male) and facet degeneration (Fujiwara grade greater than 3) predicted the development of ASD in the multivariate model (gender=4.74 [1.09-20.45], p=.037; facet degeneration=6.31 [1.09-36.52], p=.039). CONCLUSIONS: The incidence of reoperation in patients surgically treated for DS was 23.2% at a mean time of 5.9 years. A significantly higher incidence of reoperation was observed in patients treated with decompression alone compared with those treated with decompression and fusion. Body mass index and disc height were identified as independent risk factors for SSD, whereas male gender and facet degeneration were identified as independent risk factors for ASD. The results of this comprehensive review will guide spine surgeons in their preoperative planning and in the surgical management of patients with DS, thereby reducing the reoperation rate.

Postoperative behavior of thoracolumbar/lumbar curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C adolescent idiopathic scoliosis.

BACKGROUND: Controversy still exists around surgical strategies for Lenke type 1C and 2C curves with primary thoracic and compensatory lumbar curves in adolescent idiopathic scoliosis (AIS). The benefit of selective thoracic fusion (STF) for these curve types is spontaneous lumbar curve correction while saving more mobile lumbar segments. However, a risk of postoperative coronal decompensation after STF has also been reported. This multicenter retrospective study was conducted to evaluate postoperative behavior of thoracolumbar/lumbar (TLL) curve and coronal balance after posterior thoracic fusion for Lenke 1C and 2C AIS. METHODS: Twenty-four Lenke 1C and 2C AIS patients who underwent posterior thoracic fusion were included. The mean age of patients was 15.7 years old at time of surgery. Constructs used for surgery in all cases were pedicle screw constructs ending at L3 or above. Radiographic measurements were performed on Cobb angles of the main thoracic and TLL curves and coronal balance. Factors related to final Cobb angle of TLL curve and postoperative change of coronal balance were investigated. RESULTS: Mean Cobb angles for main thoracic and TLL curves were 59.0° and 43.9° preoperatively, and were corrected to 21.5° and 22.0° at final follow-up, respectively. Mean coronal balance was -5.6 mm preoperatively and was corrected to -14.6 mm at final follow-up. Final Cobb angle of TLL curve was significantly correlated with immediate postoperative Cobb angle of main thoracic curve and tilt of lowest instrumented vertebra (LIV). Postoperative change of coronal balance was significantly correlated with selection of LIV relative to stable vertebra. CONCLUSION: Spontaneous correction of TLL curve occurred consistently by correcting the main thoracic curve and making the LIV more horizontal after posterior thoracic fusion for Lenke 1C and 2C AIS. The more distal fixation to stable vertebra resulted in coronal balance shifting more to the left postoperatively.

Discordance of gravity line and C7PL in patient with adult spinal deformity--factors affecting the occiput-trunk sagittal discordance.

BACKGROUND CONTEXT: During quiet standing, the gravity line (GL) can be located according to the sum of the ground reaction forces (GRFs) measured with a force platform. C7 plumb line (C7PL) is an easy method to estimate sagittal trunk balance, but discordance between C7PL and the GL is widely recognized. However, the prevalence of occiput-trunk (O-T) discordance (GL-C7PL>3 cm) and the factors affecting this type of discordance have not yet been determined. PURPOSE: The purpose of this study was to report the prevalence of O-T discordance in adult spinal deformity (ASD) patients and identify the factors affecting this type of discordance. STUDY DESIGN: This was a retrospective consecutive case series of ASD. PATIENT SAMPLE: This retrospective case series included 300 consecutive ASD patients. The inclusion criteria were age more than 50 years, Cobb angle of the main curve more than 20°, and C7PL more than 5 cm. The exclusion criteria consisted of inappropriate radiography; syndromic, neuromuscular, or other pathologic conditions; and previous joint replacement. OUTCOME MEASURES: The outcome measures included self-reported (Scoliosis Research Society 22 and Oswestry disability index [ODI]) and radiographic measures. METHODS: In a retrospective consecutive case series, demographic and radiographic patient data were reviewed. Demographic data included age, gender, curve type, SRS22, and ODI. Radiographic data included GL, C7PL, C2-C7, T2-T5, T5-T12, T10-L2, T2 tilt, lumbar lordosis (LL), sacrum slope (SS), pelvic tilt (PT), and pelvic incidence (PI). Global sagittal and spinopelvic alignments were also reviewed. Patients were categorized in either a O-T concordance (C group, GL-C7PL<3 cm) or a O-T discordance (D group, GL-C7PL more than +3 cm) group, and the demographic, radiographic, and clinical outcome data were compared between these groups. One-way analysis of variance, correlation coefficient tests, and multiple regression and logistic regression analyses were performed for statistical analysis. p Value less than .01 was considered statistically significant. Force platform analysis was performed to assess the relationship among GRF, GL, and C7PL. RESULTS: Among 300 consecutive ASD patients, 72 (24%) were categorized in the D group. There was no significant difference in terms of demographic data between the C and D groups. The SRS and ODI of patients with GL more than 10 cm were significantly lower than those of patients with GL less than 10 cm. Comparisons of regional sagittal alignment showed significantly higher T5-T12 values in the D group, and multiple regression analysis revealed significant correlations among T2-T5, T5-T12, and GL-C7PL. In contrast, the analysis of global sagittal alignment revealed a significantly large T2 sagittal tilt in the D group compared with the C group. Force platform analysis showed concordance between GRF and GL, whereas discordance was observed between GRF and C7PL. The D group could be classified into 2 groups based on the global sagittal alignment: 10 patients were classified as the hypo-compensation type (small SVA, small CL, small TK, and normal-to-small LL), whereas 62 were classified as the forward-leaning type (large sagittal vertical axis, large cervical lordosis, large thoracic kyphosis, and small LL). CONCLUSIONS: The prevalence of discordance between GL and C7PL in ASD patients was 24%, and thoracic kyphosis and global sagittal alignment were significantly correlated with this discordance. The concordance of GRF and GL and the discordance of GRF and C7PL highlight the importance and necessity of accounting for GL when considering surgical treatment.

Incidence and the risk factors of spinal deformity in adult patient after spinal cord injury: a single center cohort study.

STUDY DESIGN: A retrospective consecutive case series of adult spinal cord injuries (SCIs) patients. OBJECTIVE: To assess the incidence and risk factors of spinal deformity in a large sample of patients with SCIs. Post-traumatic spinal deformities are well-recognized sequelae of SCIs. Despite the devastating complications for SCI patients with trunk imbalance, the incidence, clinical outcomes, and independent risk factors of scoliosis after SCI remain controversial. MATERIALS AND METHODS: We assessed 214 consecutive adult compressive SCI patients who were hospitalized in our hospital. We compared patients who developed spinal deformities with those who did not. Univariate and multivariate analyses to determine the independent risk factors were performed. Age, gender, etiology, ASIA grade (American Spinal Injury Association) surgery, and other demographic data were analyzed to determine the risk factors for developing a spinal deformity. RESULTS: The average patient age was 58.3 years (20-86 years). The etiology was trauma (n = 158), ossification of ligament (n = 22), infectious (n = 17), and others. One hundred fifty-two patients had cervical spine involved, 62 had thoracic spine involved. 26 patients classified as ASIA A, 54 were ASIA B, 96 were ASIA C, and 42 were ASIA D 4. One hundred thirty-five patients had either decompression or decompression and fusion surgery. The incidence of spinal deformities was 21 % (44/214). The mean Cobb angle was 28.9 degrees (13-38°). ASIA grade and surgery predicted the occurrence of spinal deformity in both the univariate model (ASIA grade, OR: 1.59 [95 % CI: 1.04-2.44; P = 0.032]; Surgery, OR: 4.47 [95 % CI: 1.89-10.06; P = 0.0007]) and the multivariate model (ASIA grade, OR: 1.63 [95 % CI: 1.04-2.57; P = 0.033]; Surgery, OR: 4.59 [95 % CI: 1.91-11.04; P = 0.0006]), whereas surgery was the most important risk factor in the Cox model (HR: 3.50 [95 % CI: 1.56-7.88; P = 0.0025]). CONCLUSIONS: The SCI patients with high ASIA grades and those who had undergone surgery had a higher likelihood of developing a spinal deformity. Of these risk factors, surgery was the stronger risk factor.

Lumbosacral fixation using sacroiliac buttress screws: a modification to the Jackson technique with intrasacral rods.

BACKGROUND: The use of intrasacral rods has been previously reported for posterior lumbosacral fixation. However, problems associated with this technique include poor stability of the rod in the sacrum, difficulty in contouring the rod to fit the lateral sacral mass, and the complicated assembly procedure for the rod and pedicle screws in the thoracolumbar segments after insertion of the rod into the sacrum. METHODS: We used a screw with a polyaxial head instead of an intrasacral rod, which was inserted into the lateral sacral mass and assembled to the rod connected cephalad to pedicle screws. The dorsal side of the screw was stabilized by the sacral subchondral bone at the sacroiliac joint with iliac buttress coverage, and the tip of the screw was anchored by the sacral cortex. RESULTS: Three different cases were used to illustrate lumbosacral fixation using intrasacral screws as an anchor for the spinal instrumentation. Effective resistance of flexural bending moment and fusion were achieved in these patients at the lumbosacral level. CONCLUSIONS: An intrasacral screw can be stabilized by subchondral bone with iliac buttress coverage at the dorsal and ventral sacral cortex. Posterior spinal fusion with this screw technique enables easier assembly of the instrumentation and presents better stabilization than that provided by the previously reported intrasacral rod technique for correction and fusion of thoracolumbar kyphoscoliosis.

Association of postoperative shoulder balance with adding-on in Lenke Type II adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective, multicenter study. OBJECTIVE: To investigate the relationship between postoperative shoulder balance and adding-on in Lenke type 2 adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Postoperative shoulder imbalance (PSI) and adding-on are the main postoperative complications occurring at the proximal to upper instrumented vertebra and the distal to the lower instrumental vertebra (LIV), respectively. Inadequate selection of LIV in the selective thoracic fusion surgery may result in postoperative distal adding-on. It remains unclear whether postoperative shoulder balance is associated with postoperative adding-on. METHODS: Preoperative, postoperative, and 2-year follow-up radiographs of 142 consecutive patients with Lenke type 2 curves who underwent posterior-fusion surgery were analyzed. The patients were grouped into PSI positive and negative at follow-up. Radiographical and categorical factors between patients with and without PSI were compared. The relationship between the radiographical shoulder height and the parameters of adding-on were analyzed. RESULTS: PSI occurred in 23 patients (16.2%) and distal adding-on was recognized in 20 patients (14.1%) at final follow-up. The occurrence of adding-on was significantly lower in the shoulder imbalance group at follow-up (P < 0.01). There was no shoulder imbalance occurring in the patients with distal adding-on at final follow-up (P < 0.01). Correlation analysis showed that the radiographical shoulder height was positively correlated with the change in the angulation of the first disc below LIV (r = 0.228, P ≤ 0.01) and negatively correlated with the deviation change of the LIV+1 at follow-up (r = -0.254, P ≤ 0.01). CONCLUSION: The postoperative shoulder balance and postoperative distal adding-on were weakly but significantly associated with each other, and both shoulder imbalance and adding-on need to be prevented in Lenke type 2 curves.

Factors affecting the postoperative progression of thoracic kyphosis in surgically treated adult patients with lumbar degenerative scoliosis.

STUDY DESIGN: A retrospective case series of patients treated surgically for degenerative lumbar scoliosis (DLS). OBJECTIVE: To determine incidence and risk factors of progressive global thoracic kyphosis (pGTK) after surgery for DLS. SUMMARY OF BACKGROUND DATA: Sagittal balance affects the surgical treatment of spinal deformity in adults. Little is known about the loss of sagittal balance due to pGTK, or about the risk factors for pGTK, after surgery for DLS. METHODS: We reviewed records from a multicenter database of adults with DLS, treated with posterior spinal fusion. Inclusion required an age of 50 years or more at the time of surgery, an upper instrumented vertebra at T9 and below, more than 5 fused segments, and at least 2 years of follow-up. We included 73 patients with a mean age of 68.3 years (range, 51-77 yr) and a mean follow-up period of 3.6 years (range, 2-11 yr). Independent risk factors for pGTK were identified by logistic regression analysis. RESULTS: Significant pGTK, defined as an increase in thoracic kyphosis of more than 10° from before surgery to the time of final follow-up, was observed in 41% of the patients. Loss of the sagittal vertical axis was larger in patients with pGTK than without (4.7 vs. 1.5 cm; P = 0.02). Risk analysis showed larger lumbar lordosis correction in patients with pGTK. Multivariate logistic regression analysis identified an age greater than 75 (odds ratio, 5.53; P = 0.02, 95% confidence interval [1.4-22.4]) and sacropelvic fusion (odds ratio = 2.66, P = 0.02, 95% confidence interval [1.5-11.1]) as independent risk factors for pGTK. CONCLUSION: The pGTK incidence after surgery for DLS was 41%. Age, sacropelvic fusion, and a larger sagittal correction were identified as pGTK risk factors. Long-term follow-up will provide more data on the clinical impact of pGTK in elderly patients. LEVEL OF EVIDENCE: 3.

Selection of lower instrumented vertebra in treating Lenke type 2A adolescent idiopathic scoliosis.

STUDY DESIGN: A retrospective, observational, and multicenter study. OBJECTIVE: To identify the ideal lower instrumented vertebra (LIV) to prevent distal adding-on after surgical correction of Lenke type 2A curve. SUMMARY OF BACKGROUND DATA: LIV level may affect the risk of postsurgical adding-on. The choice of the last touching vertebra (LTV)-the most caudal vertebra of the main thoracic curve that touches the central sacral vertical line when standing-as an appropriate LIV has been validated for Lenke type 1A but not type 2A curve. METHODS: Radiographs obtained before, immediately after, and 2 years after surgery were evaluated for 116 consecutive patients who underwent posterior thoracic fusion surgery for Lenke type 2A curve. The LIV was proximal to the LTV in 18 patients (PLTV), distal in 43 (DLTV), and at the LTV in 55 (ALTV). Significant independent factors associated with adding-on were analyzed first by univariate analysis, and then by stepwise logistic regression analysis. RESULTS: Distal adding-on was present in 16 patients (13.8%) at follow-up: 9 PLTV (50.0%), 3 DLTV (7.0%), and 4 ALTV (7.3%). Adding-on was significantly more common in the PLTV group. One PLTV-group patient required revision surgery to treat adding-on. Univariate analysis identified the following significant factors associated with adding-on: the T2-T5 kyphosis angle and shoulder height before, immediately after, and 2 years after surgery; the lumbar Cobb angle at the 2-year follow-up; the 2-year postoperative lumbar curve correction rate; and the difference between the LIV and the end vertebra, neutral vertebra, and LTV levels. Significant independent risk factors identified by stepwise logistic regression analysis included the clavicle angle at follow-up, the correction rate of the lumbar curve immediately after surgery, and the difference between the LIV and LTV levels. CONCLUSION: A LIV at or distal to the LTV may prevent postoperative adding-on in Lenke type 2A curve. LEVEL OF EVIDENCE: 3.

Sagittal Cervical Alignment in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective case series of surgically treated adolescent scoliosis patients. OBJECTIVES: To assess the radiographic changes of cervical kyphosis and identify the possible factors affecting postoperative sagittal cervical kyphosis in surgically treated patients with adolescent idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: Cervical kyphosis is a well-recognized phenomenon in patients with adolescent idiopathic scoliosis. Despite recent reports, the prevalence, radiographic changes, and possible factors affecting postoperative sagittal cervical kyphosis are controversial. MATERIALS AND METHODS: A retrospective review of a single-center database was performed on 133 consecutive patients with adolescent idiopathic scoliosis treated with long instrumented (more than 5 levels) spine fusion (minimum, 2 years; mean, 3.3 years; range, 2 to 5.5 years). A total of 89 patients met all of the inclusion criteria. Preoperative and postoperative radiographic measurements and patient demographics were investigated. RESULTS: Postoperative cervical kyphosis was observed in 46 patients. Cobb angle decreased from 48.1° ± 13.1° to 15.4° ± 11.1° at the final follow-up. Cervical kyphosis significantly decreased from 5.5° ± 8.9° preoperatively to -1.5° ± 8.9° at the final follow-up. No difference was observed for T2-T5, T5-T12, lumbar lordosis, sacral slope, pelvic incidence, pelvic tilt, and sagittal vertical axis during the follow-up. Notably, T2 sagittal tilt was significantly increased from preoperatively to the final follow-up. Pearson correlation coefficient test showed a strong correlation between postoperative cervical lordosis and T2 sagittal tilt (r = 0.73; p < .001). CONCLUSIONS: Despite the significant increase of cervical lordosis, 85% of patients still have a kyphotic or less lordotic cervical spine. The strong positive association between cervical lordosis and T2 sagittal tilt suggests that the sagittal cervical alignment of adolescent idiopathic scoliosis patients is closely related to the global sagittal spine balance rather than thoracic kyphosis.