RESUMEN
Cervical sagittal alignment is considered to have a special role in the pathogenesis and evaluation of cervical diseases. Previous studies have demonstrated that cervical sagittal alignment is correlated with thoracolumbar and pelvic alignments. As the direct anatomical structures connect to the cervical region, however, no parameters in the occiput have been reported to be intimately related to the alignment of the cervical spine. A retrospective radiographic study of 335 individuals (182 males and 153 females) between 18 and 60 years of age was performed between January 2007 and January 2016. The occipital incidence (OI), occipital slope (OS), occipital tilt (OT), C0-C2 angle, C2-C7 angle, C0-C7 angle, T1 slope and thoracic kyphosis were measured in every individual. The mean values of the occipital parameters of the cohort were 34.6° ± 3.1° for OI, 23.4° ± 7.4° for OS, and 11.8° ± 3.3° for OT. OI was constant throughout three age groups. No significant differences were noted between males and females. In addition, strong correlations were found between the occipital parameters and cervical parameters. The occipital orientation was an important factor that influenced the cervical sagittal alignment.
Asunto(s)
Vértebras Cervicales/anatomía & histología , Vértebras Cervicales/diagnóstico por imagen , Cuello/anatomía & histología , Cuello/diagnóstico por imagen , Orientación Espacial , Adolescente , Adulto , Estudios de Cohortes , Femenino , Humanos , Cifosis/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Radiografía/métodos , Estudios Retrospectivos , Adulto JovenRESUMEN
OBJECTIVE Previous studies have reported spinal straightening and pelvic retroversion when changing from erect to sitting posture in patients with adolescent idiopathic scoliosis (AIS), which were thought to be related to low-back pain after sitting for long periods. However, the sitting sagittal alignment after posterior spinal fusion has not been evaluated. This study aims to assess the influence of posterior fusion surgery upon sitting sagittal spinopelvic alignment in adolescents with idiopathic thoracic curves (thoracic AIS [T-AIS]). METHODS A total of 44 T-AIS patients (30 Lenke I and 14 Lenke II) from the authors' center were included in this study. Preoperative and postoperative long-cassette lateral radiographs of the spine and pelvis were obtained with the patients in standing and sitting positions. Thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were measured on standing and sitting lateral radiographs. Patients were divided into selective thoracic fusion (STF) and nonselective thoracic fusion (NSTF) groups. RESULTS At baseline, TK, LL, and SS decreased by 27.5%, 42.1%, and 31.1%, respectively, from the standing to the sitting position, while PT increased by 193.6%. After posterior spinal fusion, increased TK, LL, and SS and corresponding decreased PT were observed compared to baseline parameters in the sitting position. Comparison of postoperative sitting and standing values for the whole cohort showed that the mean LS and SS values were significantly lower in the sitting position (decreased by 14.0% and 13.9%, respectively, compared to standing), whereas the mean PT value was significantly greater (increased by 39.0%, compared to standing). Similar changes were also observed in the STF group: postoperatively the mean LL value was 15.6% lower in sitting than in standing, while the mean SS value was 11.5% lower. However, no obvious changes of the postoperative values in sitting were found in the NSTF group. CONCLUSIONS Nonselective thoracic fusion surgery in T-AIS patients diminished spinal straightening and pelvic retroversion during sitting. Reducing distal fusion levels was of special value in not only saving more lumbar mobility, but also preserving the function of pelvic posterior rotation.
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Escoliosis/fisiopatología , Escoliosis/cirugía , Sedestación , Fusión Vertebral/métodos , Vértebras Torácicas/cirugía , Resultado del Tratamiento , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Cifosis/diagnóstico por imagen , Cifosis/cirugía , Lordosis/diagnóstico por imagen , Lordosis/cirugía , Masculino , Radiografía , Estudios Retrospectivos , Escoliosis/diagnóstico por imagen , Vértebras Torácicas/diagnóstico por imagenRESUMEN
BACKGROUND: The new full power-assisted (FPA) technique used in pedicle screw placement during adolescent idiopathic scoliosis (AIS) surgery streamlines the surgical procedure and reduces repetitive surgeon tasks. However, the use of the FPA technique may also negatively affect the surgical safety and efficacy of patients with AIS. OBJECTIVE: The purpose of this study was to investigate the effect of the FPA technique on the accuracy of pedicle screw placement, as well as on operating time, blood loss, and clinical outcomes. METHODS: A total of 105 patients with AIS with major thoracic curves treated with posterior instrumentation and fusion were randomized into 2 groups. With the new FPA technique, 427 pedicle screws were implanted in the thoracic region in 35 patients (the FPA group), and using the conventional freehand (FH) technique, 896 screws were implanted in 70 patients (the FH group). The primary end point screw position was assessed using postoperative computed tomography. Secondary end points, such as operative time, blood loss, and clinical outcomes, were also assessed. RESULTS: The FPA technique did not significantly affect the accuracy rate of the pedicle screw placement, scoliosis correction, total operating time, or total blood loss. However, the surgical times for the screw insertion phase and for each screw placement were significantly shorter for the FPA group compared with the FH group (P < 0.001). CONCLUSIONS: Compared with the conventional manual tools, use of the FPA technique seemed to be superior and had relatively shorter pedicle screw placement times, with comparable surgical safety and efficacy for patients with AIS.
Asunto(s)
Cifosis/cirugía , Tornillos Pediculares , Escoliosis/cirugía , Vértebras Torácicas/cirugía , Adolescente , Niño , Femenino , Humanos , Masculino , Tornillos Pediculares/efectos adversos , Fusión Vertebral/métodos , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: The aim of this study was to prospectively compare the radiographic and clinical outcomes between the posterior fossa decompression (PFD) and PFD with duraplasty (PFDD) procedures in adolescent patients with Chiari malformation type I (CMI). METHODS: Ninety adolescent patients with CMI were randomly assigned to undergo either PFDD or PFD. In both groups, a dissection from the occipital bone was performed. The dura was not opened in the PFD group, and the outer layer of dura was resected. However, in the PFDD group, the dura mater was opened and expanded. Data were analyzed for clinical outcome, complications, and syrinx resolution. RESULTS: The age, gender, and preoperative neurologic status were similar between the 2 groups. Compared with the PFD group, patients undergoing PFDD had significantly longer operation time, longer postoperative drainage time, and higher drainage volume. At the latest follow-up, no statistically significant difference was found between the 2 groups in terms of syrinx resolution. The clinical outcomes were similar in the PFDD and PFD group. Compared with the PFD group, patients in the PFDD group had a higher incidence of cerebrospinal fluid leak. CONCLUSIONS: Compared with the more aggressive decompression with duraplasty, PFD without duraplasty produces comparable radiologic and clinical outcomes and is associated with a lower risk of complications.
Asunto(s)
Malformación de Arnold-Chiari/diagnóstico por imagen , Malformación de Arnold-Chiari/cirugía , Descompresión Quirúrgica/métodos , Duramadre/diagnóstico por imagen , Duramadre/cirugía , Adolescente , Malformación de Arnold-Chiari/fisiopatología , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Complicaciones Posoperatorias , Resultado del TratamientoRESUMEN
OBJECTIVE The aim of this study was to investigate how implant density affects radiographic results and clinical outcomes in patients with dystrophic scoliosis secondary to neurofibromatosis Type 1 (NF1). METHODS A total of 41 patients with dystrophic scoliosis secondary to NF1 who underwent 1-stage posterior correction between June 2011 and December 2013 were included. General information about patients was recorded, as were preoperative and postoperative scores from Scoliosis Research Society (SRS)-22 questionnaires. Pearson correlation analysis was used to analyze the associations among implant density, coronal Cobb angle correction rate and correction loss at last follow-up, change of sagittal curve, and apical vertebral translation. Patients were then divided into 2 groups: those with low-density and those with high-density implants. Independent-sample t-tests were used to compare demographic data, radiographic findings, and clinical outcomes before surgery and at last follow-up between the groups. RESULTS Significant correlations were found between the implant density and the coronal correction rate of the main curve (r = 0.505, p < 0.01) and the coronal correction loss at final follow-up (r = -0.379, p = 0.015). There was no significant correlation between implant density and change of sagittal profile (p = 0.662) or apical vertebral translation (p = 0.062). The SRS-22 scores improved in the appearance, activity, and mental health domains within both groups, but there was no difference between the groups in any of the SRS-22 domains at final follow-up (p > 0.05 for all). CONCLUSIONS Although no significant differences between the high- and low-density groups were found in any of the SRS-22 domains at final follow-up, higher implant density was correlated with superior coronal correction and less postoperative correction loss in patients with dystrophic NF1-associated scoliosis.
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Tornillos Óseos , Neurofibromatosis 1/complicaciones , Escoliosis , Fusión Vertebral/instrumentación , Fusión Vertebral/métodos , Vértebras Torácicas/cirugía , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Neurofibromatosis 1/cirugía , Estudios Retrospectivos , Escoliosis/diagnóstico por imagen , Escoliosis/patología , Escoliosis/cirugía , Encuestas y Cuestionarios , Vértebras Torácicas/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVE: To investigate whether posterior fossa decompression (PFD) could improve denervation of the paraspinal muscles in patients with Chiari I malformation (CMI). BACKGROUND: Paraspinal muscle denervation is one of the essential elements in the pathophysiology of CMI/syringomyelia-related scoliosis. Although PFD has been widely used for managing CMI, whether denervation of the paraspinal muscles may benefit from this neurosurgical procedure remains ambiguous. Bax and Bcl-2 are two regulators of apoptosis that are closely related to the innervation status of skeletal muscles, and denervation is associated with upregulated Bax and downregulated Bcl-2. METHODS: Thirty-seven patients who underwent PFD and subsequent deformity correction for CMI-associated scoliosis were enrolled. Biopsy specimens were obtained from bilateral erector spinae muscles during both procedures with an average interval of 6.5 months. The biopsy site was located within the spinal innervation region involved by the syrinx and near the level of upper instrumented vertebra. The expression levels of Bax and Bcl-2 as well as histological features of the muscle fibres were examined at the two time points. RESULTS: After PFD, the mRNA level of antiapoptotic Bcl-2 was elevated by 178% and 260% in the convex and concave muscles, respectively, with a coincident decrease of 69% and 73% for proapoptotic Bax at the corresponding sites (p<0.001). Consistent with the mRNA data, the Bcl-2 protein in the paraspinal muscles was increased by 75% on the convex and by 169% on the concave side following PFD. For Bax protein, decreases of 45% and 52% were detected in the convex and concave muscles, respectively (p<0.001). On average, these changes led to a 60% decrease in the Bax/Bcl-2 ratio, suggesting reduced apoptotic signalling and improved innervation of the paraspinal muscles. Histologically, the specimens demonstrated improvements in denervation-associated changes of the muscle fibres following PFD, with the number of atrophic and necrotic/degenerated fibres decreasing significantly from 6.7 and 8.5 before surgery to 3.2 (p=0.012) and 4.2 (p<0.001) after surgery, respectively. CONCLUSION: In patients with CMI, treatment with PFD led to a decrease in the Bax/Bcl-2 ratio at both the mRNA and protein levels, indicating an attenuated susceptibility to apoptotic cell death. These data, coupled with the observed improvements in histopathological features of the myofibres, suggest that PFD in Chiari I ameliorates denervation of the paraspinal muscles.
Asunto(s)
Malformación de Arnold-Chiari/cirugía , Fosa Craneal Posterior/cirugía , Descompresión Quirúrgica , Desnervación , Músculos Paraespinales , Humanos , Estudios Retrospectivos , Siringomielia/cirugíaRESUMEN
Background. Halo gravity traction (HGT) is one of the most commonly used perioperative techniques for the treatment of severe kyphoscoliosis. This study was to explore the influence of HGT on the BMD of these patients. Methods. Patients with severe kyphoscoliosis treated by preoperative HGT for at least 2 months were included. Patients' BMD were assessed by dual-energy X-ray absorptiometry at lumbar spine (LS, L2-L4) and femur neck (FN) of the nondominant side. The weight and duration of traction, as well as baseline characteristics, were recorded. Results. Twenty patients were recruited. The average traction duration was 77.9 ± 13.0 days while the mean traction weight was 39.9% ± 11.1% of total body weight. Remarkable decrease of BMD was observed at LS of 17 (85%) patients and at FN of 18 (90%) patients. After HGT, 75% of patients were found to have osteoporosis, the incidence of which was significantly higher than that before HGT (35%). The correlation analysis revealed BMD reduction was only significantly correlated with the traction duration. Conclusions. The current study showed that preoperative HGT can have obvious impact on the BMD. The BMD reduction is associated with traction duration, suggesting that long traction duration may bring more bone mineral loss.
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Densidad Ósea , Tirantes/efectos adversos , Cifosis/fisiopatología , Cifosis/terapia , Osteoporosis/etiología , Tracción/efectos adversos , Adolescente , Gravitación , Humanos , Cifosis/diagnóstico , Osteoporosis/diagnóstico , Osteoporosis/fisiopatologíaRESUMEN
BACKGROUND: Though several studies have reported the incidence of intraspinal neural axis abnormalities in infantile and juvenile "presumed idiopathic" scoliosis, there has been a varying prevalence ranging from 11.1 to 26.0% based on a limited sample size. Therefore, such inconclusive findings have resulted in some questions on the MRI-associated role in the management of these patients. We aimed to investigate the prevalence and distribution of intraspinal anomalies in the infantile and juvenile patients with "presumed idiopathic" scoliosis and to explore the radiographic and clinical indicators with large sample size. METHODS: A total of 504 infantile and juvenile patients diagnosed with "presumed idiopathic" scoliosis were examined for potentially-existing neural axis abnormalities by MRI. Patients were grouped into two cohorts according to the presence of neural axis abnormalities. Radiographic parameters including curve magnitude, curve pattern, location of apex, degree of thoracic kyphosis, and span of curve were recorded and compared between the two groups. The prevalence of the neural abnormalities between the infantile-age group and juvenile-age group was also compared. The student t test was used to evaluate the differences of continuous variables and the chi-square test was used to evaluate the difference of categorical variables. Fisher exact test was applied to detect the difference of the rate of intraspinal anomalies between the "infantile idiopathic scoliosis" and "juvenile idiopathic scoliosis" group. RESULTS: Involving the spinal cord, 94 patients (18.7%) were found to have a neural abnormality: Arnold-Chiari malformation alone in 43 patients, Arnold-Chiari malformation combined with syringomyelia in 18 patients, isolated syringomyelia in 13 patients, diastematomyelia in six patients, tethered cord combined with diastematomyelia in six patients, tethered cord alone in four patients, and other uncommon intraspinal abnormalities in the remaining four patients. Totally Arnold-Chiari malformation with or without syringomyelia accounted for 64.8% (61/94) among all these abnormalities. Male gender, left thoracic curve and right lumbar curve were found to be significantly associated with the presence of neural axis abnormalities on MRI. CONCLUSIONS: The incidence of neural axis abnormalities in the presumed IIS and JIS was 18.7%. Thus a routine MRI evaluation appears warranted for those "presumed idiopathic" scoliosis patients if aged less than 10 years, being male or having left thoracic or right lumbar curve.
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Malformación de Arnold-Chiari/diagnóstico por imagen , Imagen por Resonancia Magnética , Defectos del Tubo Neural/diagnóstico por imagen , Escoliosis/diagnóstico por imagen , Siringomielia/diagnóstico por imagen , Malformación de Arnold-Chiari/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Defectos del Tubo Neural/epidemiología , Prevalencia , Estudios Retrospectivos , Escoliosis/epidemiología , Siringomielia/epidemiologíaRESUMEN
STUDY DESIGN: A retrospective study. OBJECTIVE: To evaluate the effect of preoperative clavicle chest cage angle difference (CCAD) on postoperative radiographic shoulder imbalance, cosmetic shoulder balance, patient's satisfaction, and surgeon's fulfillment in Lenke I adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: CCAD is a novel predictor of postoperative radiographic shoulder imbalance in AIS. However, radiographic shoulder balance does not always correspond to cosmetic shoulder balance. METHODS: Forty-four Lenke I AIS patients treated with posterior spinal fusion with a minimum 2-year follow-up were analyzed. Shoulder height difference (SHD) and CCAD were measured on anteroposterior standing radiographs. The inner shoulder height (SHi) and the outer shoulder height (SHo) were measured using the patients' photographs. The patients' satisfaction and the surgeons' fulfillment were evaluated using a questionnaire. A receiver operative characteristic curve analysis was performed to explore the threshold values of preoperative CCAD in the prediction of the final follow-up radiographic shoulder imbalance, patients' satisfaction, and surgeons' fulfillment. RESULTS: At the final follow-up, the preoperative CCAD was significantly greater in patients with unbalanced shoulders (SHD ≥1âcm). For cosmetic shoulder balance at the final follow-up, there was no significant difference in preoperative CCAD between Group 1i (SHiâ≥1âcm, nâ=â14) and Group 2i (SHiâ<1âcm, nâ=â30), and the preoperative CCAD was also similar between Group 1o (SHoâ≥1âcm, nâ=â17) and Group 2o (SHoâ<1âcm, nâ=â27). For patients' satisfaction and surgeons' fulfillment, the preoperative CCAD was significantly greater in patients with unsatisfied outcomes. The threshold value of preoperative CCAD to predict the final follow-up radiographic shoulder imbalance, patients' satisfaction, and surgeons' fulfillment was 5.5°. CONCLUSION: CCAD is a good radiographic predictor for postoperative radiographic shoulder imbalance in Lenke I AIS patients. Moreover, it is also associated with the patients' satisfaction and surgeons' fulfillment postoperatively. However, CCAD cannot predict postoperative cosmetic shoulder balance. LEVEL OF EVIDENCE: 4.
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Clavícula/cirugía , Cifosis/cirugía , Complicaciones Posoperatorias/fisiopatología , Equilibrio Postural , Caja Torácica/cirugía , Escoliosis/cirugía , Hombro/fisiopatología , Fusión Vertebral , Vértebras Torácicas/cirugía , Adolescente , Niño , Clavícula/diagnóstico por imagen , Femenino , Humanos , Masculino , Satisfacción del Paciente , Periodo Posoperatorio , Estudios Retrospectivos , Caja Torácica/diagnóstico por imagen , Fusión Vertebral/efectos adversosRESUMEN
BACKGROUND: Practice guidelines for deformity correction in patients with syringomyelia-associated scoliosis (SMS) remain ill defined. Although surgeons experienced in treating adolescent idiopathic scoliosis (AIS) are commonly called on to treat SMS, no study has directly compared the results of surgical treatment between patients with SMS and those with AIS. The present study was performed to compare the radiographic and clinical outcomes of posterior spinal fusion between patients with right-thoracic SMS and those with right-thoracic AIS. METHODS: Sixty-nine adolescents with SMS were matched with patients with AIS for sex, age, and curve magnitude. Patients were evaluated before surgery, immediately after surgery, and at the latest follow-up examination for changes in curve correction, global coronal balance, and scores on the Scoliosis Research Society (SRS)-22 questionnaire. RESULTS: The preoperative primary curve magnitude was similar between the two groups, but a trend toward less flexibility was observed in the SMS group. The amount of correction of the thoracic Cobb angles obtained surgically (68% compared with 71%) and the ratio of percent correction to flexibility (1.80 compared with 1.76) were similar in the SMS and AIS groups. At the latest evaluation, eight patients with SMS and five with AIS had lost >10° of thoracic spine correction (p = 0.382). The postoperative coronal decompensation averaged 13% and 6%, respectively, in the SMS and AIS groups (p = 0.243). No intergroup differences were noted with respect to the sagittal vertical axis or proximal junctional change, with preservation of global sagittal balance in both groups during follow-up. There were no neurologic or other major complications related to surgery in either group. CONCLUSIONS: Despite the differences in preoperative status, adolescents with idiopathic right thoracic scoliosis and those with syringomyelia-associated right thoracic scoliosis had comparable clinical and radiographic outcomes of pedicle-screw-based posterior spinal fusion, without neurologic complications.
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Escoliosis/cirugía , Fusión Vertebral , Siringomielia/complicaciones , Vértebras Torácicas/cirugía , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos , Escoliosis/etiología , Resultado del TratamientoRESUMEN
PURPOSE: To investigate the predictive role of rib-vertebral angle (RVA) measurements in early adolescent idiopathic scoliosis (AIS) girls with right thoracic curve during brace treatment. METHODS: Early AIS (premenarchal and Risser 0) girls who had undergone brace treatment and had been followed regularly were recruited to this study. According to the bracing outcome, they were divided into Group A (non-progressed) and Group B (curve worsened over six degrees or indicated for surgery). RESULTS: Totally 48 girls were included. There were 30 and 18 patients in Groups A and B, respectively. Ratio of curve progression was significantly higher in patients with initial RVA difference (RVAD) ≥20° versus <20°, or convex RVA (CRVA) ≤68° versus >68°. From brace initiation to the latest follow-up, CRVA was found to be significantly higher in Group A versus Group B (P < 0.05), while RVAD was higher in Group B versus Group A (P < 0.05). Serial measurements revealed an increasing trend for RVAD (from 19 ± 10° to 29 ± 8°) yet a decreasing trend for CRVA (from 68 ± 6° to 60 ± 7°) in Group B, but both RVAD and CRVA were found to remain stable in Group A during the follow-up period. Association analyses showed that both RVAD ≥20° and CRVA ≤68° at brace initiation and at each follow-up were significantly associated with curve progression. CONCLUSIONS: The initial RVAD ≥20° and CRVA ≤68° serve as valid factors in predicting the risk of curve progression during bracing in early AIS. Constant watch on RVAD and CRVA can help to more accurately predict the effectiveness of bracing in these patients.
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Tirantes , Progresión de la Enfermedad , Costillas/diagnóstico por imagen , Escoliosis/terapia , Vértebras Torácicas/diagnóstico por imagen , Adolescente , Niño , Femenino , Estudios de Seguimiento , Humanos , Estudios Retrospectivos , Escoliosis/clasificación , Escoliosis/diagnóstico por imagenRESUMEN
PURPOSE: To investigate whether the posterior cranial fossa (PCF) morphology in Chiari I malformation without syringomyelia (also called syrinx) (CMI-only) is different from that in Chiari I malformation with syrinx (CMI-S). METHODS: Nineteen CMI patients without syrinx constituted the CMI-only group, whereas 48 CMI patients with syrinx were assigned to the CMI-S group. Another cohort of 40 age-matched asymptomatic adolescents was enrolled to serve as the control group. Six measurements were evaluated and compared between these three groups from T1-weighted magnetic resonance (MR) imaging, including the length of the clivus (AB), the anteroposterior diameter of the foramen magnum (BC), the length of the supraocciput (CD), the anteroposterior diameter of the posterior fossa (DA), the posterior fossa height (BE) and the clivus gradient ([Formula: see text]). The posterior cranial fossa morphology in relation to syrinx severity was also investigated. RESULTS: Compared to the normal controls, the AB, CD, DA, BE and [Formula: see text] were significantly larger in the CMI-S group. Similar changes in AB, CD, DA and BE were also demonstrated in the CMI-only group, while the clivus gradient ([Formula: see text]) was found to be normal when compared with the control group. A significantly decreased clivus gradient was observed in the CMI-S group as compared to CMI-only group. In addition, the clivus was significantly flattened in patients with a distended-syrinx in comparison to those with a non-distended syrinx. CONCLUSIONS: Small size of the posterior fossa was detected both in CMI cases with and without syrinx. The clivus gradient served as the only morphologic difference in the PCF between CMI-S and CMI-only patients and was correlated with the severity of the syrinx, may support the theory that the restricted circulation of cerebrospinal fluid at the anterior paramedial subarachnoid space contributes to the formation of a syrinx.
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Malformación de Arnold-Chiari/patología , Fosa Craneal Posterior/patología , Siringomielia/patología , Adolescente , Malformación de Arnold-Chiari/complicaciones , Malformación de Arnold-Chiari/diagnóstico por imagen , Estudios de Casos y Controles , Niño , Fosa Craneal Posterior/diagnóstico por imagen , Femenino , Foramen Magno/diagnóstico por imagen , Foramen Magno/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Radiografía , Espacio Subaracnoideo/patología , Siringomielia/diagnóstico por imagen , Siringomielia/etiología , Adulto JovenRESUMEN
STUDY DESIGN: A retrospective radiographic analysis. OBJECTIVE: The aim of this study was to investigate the scoliosis curve patterns/features and magnetic resonance imaging (MRI) tonsillar ectopia characteristics in Chiari I malformation without syringomyelia (CMI-only). SUMMARY OF BACKGROUND DATA: The development of scoliosis associated with a CMI typically has been ascribed to the presence of syringomyelia. However, a subset of CMI patients with scoliosis may not have a concomitant syrinx. Scoliosis in these patients has been very poorly documented in the literature. METHODS: A retrospective study was conducted on patients with a scoliosis secondary to CMI-only. The curve direction, curve pattern/features, and side of the dominant tonsillar ectopia were recorded and assessed quantitatively. On the basis of the measurement results, associations between the scoliosis curve patterns/features and MRI tonsillar ectopia characteristics were analyzed. RESULTS: A total of 26 patients, consisting of seven males and 19 females with an average age of 15.4 years, were included in the current study. In 19 patients with asymmetrically displaced tonsils, the concordance between the dominant side of the asymmetrically displaced tonsils and curve direction was 78.9%. A statistically significant association was found between the dominant side of the tonsillar ectopia and the convex side of scoliosis according to Fisher exact test (Pâ=â0.045). In addition, it was noted that there was a high incidence (52.9%) of atypical curve patterns in CMI-only patients. A significantly high incidence of atypical features with a superior shift of either the apical or the end vertebrae was found in 85.7% of thoracic curves and 40% of lumbar curves. CONCLUSION: Scoliosis associated with CMI-only was found to have atypical curve patterns in all cases, and the direction of scoliosis was highly consistent with the dominant side of asymmetrically tonsillar herniation. These findings should be considered as an argument in favor of a nonidiopathic etiology and lead to more evidence that simple tonsillar impaction can provide enough impetus to produce or exaggerate scoliotic curvature. LEVEL OF EVIDENCE: 3.
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Malformación de Arnold-Chiari/diagnóstico por imagen , Malformación de Arnold-Chiari/epidemiología , Imagen por Resonancia Magnética/métodos , Escoliosis/diagnóstico por imagen , Escoliosis/epidemiología , Siringomielia , Adolescente , Adulto , Niño , Femenino , Humanos , Masculino , Estudios Retrospectivos , Adulto JovenRESUMEN
PURPOSE: Although the more readily available MR imaging has brought about more incidental findings of idiopathic syringomyelia (IS), no published study has specifically addressed the clinical and imaging features of IS-associated scoliosis. Since IS and Chiari I malformation (CMI)-type syringomyelia are hypothesized to share a common underlying developmental pathomechanism, this study aimed to investigate the scoliosis curve patterns and MRI syrinx cord characteristics of patients with IS comparing with those seen in CMI. METHODS: Sixty-one patients with scoliosis secondary to IS were identified and reviewed retrospectively. The curve pattern and specific curve features were recorded and compared with historic CMI controls. Location, size, and morphological appearance of the syrinx were systematically assessed on MR images. RESULTS: The maximal syrinx/cord ratio and rostrocaudal length of the syrinx in IS averaged 0.43 ± 0.16 (range 0.17-0.78) and 4.6 ± 2.5 (range 2-15) vertebral levels, respectively, both of which were smaller than those reported in CMI-type syringomyelia. Regarding the characteristics of IS-related scoliosis, sagittal profiles as well as the frequency of curve patterns and atypical features were all found to resemble those in patients with CMI (P > .05). Among the 47 individuals with a single thoracic curve, Fisher exact test revealed a significant correlation between curve convexity and the dominant side of deviated syrinx (83.3 % concordance rate, P = .021). In addition, apex of the thoracic curve trended toward being significantly correlated with the level of maximum expansion of the syrinx (P = .066). CONCLUSIONS: Radiological characteristics of scoliosis were found to be similar between idiopathic and CMI-type syrinx in both the coronal and sagittal planes, adding further evidence to the concept that these entities may be part of a spectrum of disease sharing a common pathophysiological mechanism. The thoracic spine in IS patients tended to be convex to the deviated side of syrinx, which indirectly supported the likely role of spinal cord dysfunction in the pathogenesis of syrinx-associated spinal deformities.
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Malformación de Arnold-Chiari/patología , Escoliosis/patología , Columna Vertebral/patología , Siringomielia/patología , Adolescente , Malformación de Arnold-Chiari/complicaciones , Niño , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Estudios Retrospectivos , Escoliosis/complicaciones , Siringomielia/complicaciones , Adulto JovenRESUMEN
STUDY DESIGN: A prospective observational analysis. OBJECTIVE: The aim was to perform a quantitative analysis of the neuronal status in cervical syringomyelia secondary to Chiari I malformation (CMI-S) using diffusion tensor imaging. SUMMARY OF BACKGROUND DATA: Syringomyelia is a common finding in patients with CMI. Conventional imaging techniques frequently fail to assist clinicians in quantitatively assessing the neural damage in these patients. METHODS: Twenty-three patients with CMI-S (aged 8-25 yr) were prospectively enrolled from April 2012 to August 2013. Sensitivity encoding single-shot echo-planar imaging was used for the sagittal diffusion tensor imaging. Fractional anisotropy (FA) values in the spinal cord were compared between the patients and normal volunteers and further evaluated with respect to syrinx severity and neurological signs/symptoms. RESULTS: Compared with the normal controls, the FA values were significantly decreased at the level of the syrinx (0.429 ± 0.015 vs. 0.533 ± 0.007; P < 0.001), whereas no significant decreased FA value was measured in the tissue rostral and caudal to the syrinx. Concerning patients with different size of the syrinx, significantly decreased FA values at the syrinx level were observed in patients with a distended syrinx in comparison with those with a nondistended syrinx (0.397 ± 0.013 vs. 0.480 ± 0.018; P < 0.001). Moreover, the FA value at the syrinx level was found to be significantly decreased in the symptomatic group when compared with the nonsymptomatic or control groups (P < 0.05), and there was also a significant difference between the 2 latter groups (P < 0.05). CONCLUSION: Decreased FA value at the syrinx levels may provide evidence of increased microstructural damage within the spinal cord parenchyma at this area, and changes in this diffusion tensor imaging parameter are significantly related to syrinx size and to the appearance of neurological signs/symptoms. LEVEL OF EVIDENCE: 4.
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Malformación de Arnold-Chiari/complicaciones , Vértebras Cervicales/patología , Imagen de Difusión Tensora/métodos , Siringomielia/etiología , Siringomielia/patología , Adolescente , Adulto , Anisotropía , Malformación de Arnold-Chiari/patología , Estudios de Casos y Controles , Niño , Imagen Eco-Planar , Femenino , Humanos , Masculino , Estudios Prospectivos , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad , Médula Espinal/patología , Siringomielia/diagnóstico , Adulto JovenRESUMEN
STUDY DESIGN: A genetic association study of leptin receptor (LEPR) gene with adolescent idiopathic scoliosis (AIS) in the Chinese Han population. OBJECTIVE: To determine whether LEPR gene polymorphisms are associated with the predisposition and/or disease severity of AIS. SUMMARY OF BACKGROUND DATA: Patients with AIS were reported to have lower body mass index (BMI), abnormal leptin bioavailability, and systemic lower bone mass, which implied that leptin/LEPR signaling pathway may be implicated in the etiology of AIS. Previous association study of the polymorphisms in leptin gene did not show significant differences between AIS cases and controls. However, no study has been done to investigate the relationship between genetic polymorphisms of the LEPR gene and susceptibility to AIS. METHODS: 570 patients with AIS aged 10 to 18 years were enrolled, and 570 age-matched healthy subjects were recruited as controls. 6 single nucleotide polymorphisms (SNPs) (rs1137101, rs1137100, rs4655555, rs2767485, rs1751492, and rs8179183) of LEPR gene were selected. The polymorphisms were genotyped using the polymerase chain reaction (PCR)-based Invader assay. Case-control study was performed to define the contribution of the 6 SNPs to predisposition of AIS. 1-way analysis of variance (ANOVA) test was used to compare the mean Cobb angles and BMI among patients with different genotypes in case-only analyses. Statistical significance was set at P < 0.05. RESULTS: Both the genotype and allele frequencies of SNP rs2767485 were significantly different between the patient with AIS and the control groups. No significant difference of allele frequency was noted in other 5 SNPs between the patients with AIS and the normal controls. Both the mean maximum Cobb angles and BMI of different genotype AIS groups were similar to each other for all the 6 SNPs (P > 0.05). CONCLUSION: Polymorphism of rs2767485 in LEPR gene is associated with the occurrence of AIS, suggesting LEPR is a predisposition gene.
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Predisposición Genética a la Enfermedad , Polimorfismo de Nucleótido Simple , Receptores de Leptina/genética , Escoliosis/genética , Adolescente , Alelos , Estudios de Casos y Controles , Niño , Femenino , Frecuencia de los Genes , Estudios de Asociación Genética , Genotipo , Humanos , MasculinoRESUMEN
PURPOSE: Chiari malformation type I (CMI) is characterized by deformed hindbrain. This study aimed to quantitatively evaluate the alterations in position of hindbrain after Posterior fossa decompression (PFD), and to identify the factors associated with syrinx resolution in pediatric patients with CMI. METHODS: Eighty-seven patients, aged from 5 to 18 years, who underwent PFD for CMI between September 2006 and September 2012 were retrospectively reviewed. On mid-sagittal MR images, the position of medulla oblongata and cerebellum was quantitatively evaluated preoperatively and at follow-up. The maximal syrinx/cord (S/C) ratio and syrinx length were also measured. Significant improvement of syrinx was defined as a more than 20 % decrease in maximal S/C ratio or length on follow-up MRI. RESULTS: Neurological deficits were found in 51 of the 87 patients preoperatively and 37 (72.4 %) of them obtained improvement of their symptoms at the last visit. Overall, upward shifting of the tip of cerebellar tonsil was observed in 66 (75.9 %) patients at the last follow-up. Moreover, the mean longitudinal distance of the tip of cerebella tonsil changed from 16.47 ± 5.00 to 13.89 ± 4.38 mm (P < 0.001) at final follow-up. Significant syrinx resolution was noticed in 79 (90.8 %) cases. Pointed cerebellar tonsils were found in 85 (97.7 %) of our patients preoperatively and 78 (91.8 %) of them acquired round cerebellar tonsils after PFD. The improvement of maximal S/C ratio was significantly correlated with upward shifting of the tip of cerebellar tonsil (P = 0.023). CONCLUSIONS: Following PFD for CMI, position and morphology of the cerebellar tonsil could revert to normal in most of the pediatric patients, and the upward shifting of the tip of cerebellar tonsil is significantly correlated with syrinx improvement. From this study, PFD without shunting may be effective for syrinx secondary to CMI in pediatric population.
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Malformación de Arnold-Chiari/cirugía , Cerebelo/patología , Fosa Craneal Posterior/cirugía , Descompresión Quirúrgica , Siringomielia/cirugía , Adolescente , Niño , Preescolar , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Estudios RetrospectivosRESUMEN
PURPOSE: While correction surgery for syringomyelia-associated scoliosis frequently results in an elongation of the spine and may potentially influence the natural history of syringomyelia, a paucity of data exists regarding the syrinx behavior in the postoperative course. This study aimed to investigate the natural evolution of syrinx in patients undergoing one-stage posterior instrumented spinal fusion for treatment of scoliosis associated with idiopathic syringomyelia (IS). METHODS: Twenty-two patients with IS-associated scoliosis treated with one-stage posterior correction and fusion were evaluated at a minimum of 12-month clinical and MRI follow-up (mean 29.6 months; range 12-57 months). All syringes were located within the cervical or cervicothoracic region. Standing anteroposterior radiographs were examined for primary curve magnitude and postoperative correction. On preoperative and follow-up T2-weighted MR images, location, configuration and size of the syrinx cavity were systematically assessed, and significant syrinx resolution was defined as any more than 20% decrease in length or maximal syrinx/cord ratio. RESULTS: Postoperative percent correction of the primary curve averaged 64.0 ± 15.7% and was well maintained (58.5 ± 11.5%) at latest evaluation. Regarding syrinx size, although paired t test revealed no statistically significant difference between pre- and postoperative maximal syrinx/cord ratios (0.44 versus 0.41; P > 0.05), 10 of 22 (45.5%) patients were found to meet the criteria for significant syrinx resolution. Additionally, 11 (50.0%) patients had syrinx stabilization, whereas syrinx deterioration was observed only in 1 case (4.5%) at final follow-up. Using Spearman correlation test, improvement rate of the maximal syrinx/cord ratio was found to be strongly related to the coronal percent correction of the primary curve (r = -0.547, P = 0.008). There were no neurologic or other major complications related to the surgery. CONCLUSIONS: For treatment of scoliosis associated with IS in the setting of minimal neurological deficits, one-stage spinal fusion with a lengthening of the vertebral column provides an effective coronal and sagittal correction without neurologic complications. Following surgery, the vast majority (95.5%) of syringes shrank or remained stable, indicating that deformity correction did not exert a deleterious effect on the natural evolution of syringomyelia.
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Escoliosis/cirugía , Fusión Vertebral/efectos adversos , Siringomielia/cirugía , Adolescente , Adulto , Niño , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Periodo Posoperatorio , Postura , Estudios Retrospectivos , Escoliosis/etiología , Fusión Vertebral/métodos , Columna Vertebral/cirugía , Siringomielia/complicaciones , Siringomielia/patología , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVE: To explore the natural history of scoliosis after posterior fossa decompression (PFD) in patients with Chiari malformation/syringomyelia and examine the risk factors associated with curve progression. METHODS: A retrospective radiographic study was performed at our scoliosis center for 26 patients undergoing PFD for Chiari malformation between January 2002 and December 2007. Their clinical and radiological parameters, including age, curve magnitude, curve pattern, extent of cerebellar tonsil herniation, maximal syrinx/cord ratio, syrinx size and length, were evaluated pre- and postoperatively. Curve progression was defined as an increment of Cobb angle over 5° compared with that of initial curve (progression group); whereas an increment of Cobb angle equal to or under 5° was considered curve stabilization or improvement (non-progression group). All aforementioned parameters at the time of PFD were compared between two groups with Student t and Fisher exact tests. RESULTS: Their average initial age, curve magnitude and follow-up duration were 10.3 ± 2.4 (6.5-14.7) years, 33.5° ± 7.7° (20°-45°) and 57.5 ± 26.9 (24-118) months respectively. At the final follow-up, curve improvement or stabilization occurred in 11 (42%) patients. Compared with the non-progression group, significantly greater initial age was observed in the progression group (11.1 ± 2.2 vs 9.2 ± 2.2 years, P = 0.041). In addition, the percentage of double major curve was significantly higher in the progression group than that in the non-progression group (26.7% vs 9.1%, P = 0.037). With regards to Cobb angle, Risser sign, extent of cerebellar tonsil herniation, maximal syrinx/cord ratio, syrinx length, sagittal parameters and percentage of patients with preoperative neurological signs or symptoms, no significant differences existed between two groups (P > 0.05). CONCLUSION: PFD may halt curve progression in 42% of patients with Chiari malformation/syringomyelia. And those with older age or double major curves are more likely to experience the progression of scoliosis during the post-PFD course.
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Malformación de Arnold-Chiari/cirugía , Escoliosis , Siringomielia/cirugía , Adolescente , Malformación de Arnold-Chiari/complicaciones , Niño , Descompresión Quirúrgica/efectos adversos , Femenino , Humanos , Masculino , Remisión Espontánea , Estudios Retrospectivos , Escoliosis/etiología , Siringomielia/complicacionesRESUMEN
PURPOSE: Spinopelvic alignment is increasingly considered as a main factor in the energy-efficient posture of the individual in normal and pathological status. However, the spinopelvic characteristics in Scheuermann's kyphosis (SK) are poorly defined in the literature. The purpose of this study was to determine whether differences of the spinopelvic parameters exist between adolescents with SK and age-matched normal controls. METHODS: In this study, 55 patients with SK and 60 healthy age-matched adolescents were recruited consecutively. Sagittal spinal and pelvic parameters were measured from the standing lateral radiograph, including global kyphosis, thoracic kyphosis (TK), cervical lordosis (CL), lumbar lordosis (LL), pelvic incidence (PI), sacrum slope (SS), pelvic tilt (PT) and sagittal vertical axis (SVA). According to the location of the kyphosis, patients were subdivided into Scheuermann's thoracic kyphosis (STK) group and Scheuermann's thoracolumbar kyphosis (STLK) group. The radiographic comparison and correlation analysis were further performed. RESULTS: SK patients had significantly lower PI and PT than normal controls (32.0° vs. 45.0°, P < 0.001 for PI; 0.2° vs. 11.9°, P < 0.001 for PT). The rate of a negative PT was 41.8 % (22/55) in SK patients, which was remarkably higher than in normal controls (10.0 %, 6/60). The CL, TK and LL were significantly increased in STK group when compared with STLK and control groups. A significant correlation was noticed between TK and CL and also between TK and LL in STK group. Both TK and LL were decreased in STLK patients, and a significant correlation was found between them (r = -0.687, P < 0.001). A significantly strong correlation was also observed between LL and SS in STLK patients (r = -0.641; P < 0.001). CONCLUSION: Adolescents with SK have a significantly lower PI when compared with age-matched normal controls. Patients with different curve patterns (STK vs. STLK) could have distinct compensatory mechanisms to maintain the sagittal balance.