特发性脊柱侧凸三维矫正技术研究进展

目的对特发性脊柱侧凸(idiopathic scoliosis,IS)三维矫正技术研究现状及矫形效果进行综述。方法广泛查阅近年来IS三维矫正技术相关文献,进行综述。结果 IS三维矫形越来越受到重视,各种手术方式及新的矫正技术被应用于IS矫形手术中,已取得了令人满意的三维矫形效果。结论随着对IS患者脊柱畸形认识的不断加深以及矫形理念的不断更新,更为安全、有效的矫正技术将成为IS患者脊柱三维矫形研究的热点。     

Morphology of the paravertebral muscles in adolescent idiopathic scoliosis

Histochemical studies of paravertebral muscles in idiopathic scoliosis have shown a consistently higher proportion of type I fibers on the convex side. In this study of the transversospinal muscles in moderate idiopathic scoliosis, we could demonstrate a lower type II B/II A fiber ratio on the convex side, along with an increased proportion of type I fibers. The capillary count was also higher on the convex side, especially around the type I fibers. The few pathologic changes found were predominately seen in the gravest cases of scoliosis. It is concluded that the fiber type distribution, capillary count, and metabolic enzyme activity on the convex side resembles that seen after endurance training. This suggests a secondary adaptive origin of these changes.     

脊柱侧凸三维矫形并发症的临床分析

 目的 探讨脊柱侧凸三维矫形手术的并发症及其防治策略。方法 2004年12月至2011年6月,应用三维矫形系统治疗各型脊柱侧凸727例：男245例,女482例;年龄3~62岁,平均18.2岁。冠状面Cobb角32°~142°,平均87.6°;矢状面Cobb 角-10°~75°,平均45°。结果 术后随访12~90个月,平均62.5个月。全组病例均安全完成矫形手术,冠状面矫正率55%~98%,平均85.2%;矢状面矫正率35%~67%,平均47.5%。本组病例术中、术后无一例死亡。术中、术后无脊髓损伤,102例患者共发生113例次并发症。内固定相关并发症26例：即椎弓根螺钉松动5例,断钉5例,断棒8例,脱钩3例,椎弓根切割5例,其中14例(椎弓根螺钉松动5例,断钉4例,断棒5例)发生于早期成人脊柱侧凸矫形术后。矫形并发症65例：交界性后凸36例,包括近端交界性后凸21例(其中11例为神经肌肉型侧凸),远端交界性后凸15例(其中4例马凡综合征伴脊柱侧凸,6例神经肌肉型侧凸);adding-on现象22例;平背畸形7例。内科并发症(肺部并发症、肠系膜上动脉综合征)13例。手术相关并发症(伤口感染、压疮)9例。结论 脊柱侧凸矫形术如术前准备充分、术中与术后处理得当,脊髓、神经损伤能获得有效预防。对于成人脊柱侧凸,顶椎区予以充足的内固定可有效减少断钉、断棒、椎弓根螺钉松动等内固定相关并发症;对于神经肌肉型侧凸、马凡综合征伴脊柱侧凸,适当延长融合节段可有效减少交界性后凸的发生。     

脊柱侧凸的数字化三维重建及临床应用

目的评价三维重建在脊柱侧凸诊断和治疗中的价值。方法确诊为不同类型的脊柱侧凸患者36例,36例患者分为2组：三维重建组16例,对照组20例。三维重建组术前进行单椎体椎弓根平面扫描重建,评价椎弓根的旋转角度、适宜进钉点、进钉长度、矢状位倾斜角度。术中均采用徒手椎弓根穿刺技术记录术中一次性椎弓根穿刺成功率。术后根据CT检查评估椎弓根螺钉植入位置,穿孔螺钉测量与理想进钉角度差。X线评价术后Cobb角和矫正率。结果 Cobb角：三维重建组为（36.70±16.6）°,对照组为（37.30±13.2）°,矫正率分别为71.3%和65.1%。椎弓根一次穿刺成功率：三维重建组为96.3%,对照组为79.5%,穿孔率：三维重建组为3.3%,对照组为11.5%。结论三维重建能够更好地显示脊柱侧凸的情况,有助于判断脊柱侧凸的类型和累及节段,为临床制定个性化的手术方案提供依据。     

In vivo three-dimensional segmental analysis of adolescent idiopathic scoliosis

Introduction  

An accurate assessment of three-dimensional (3D) intervertebral deviation is crucial to the better surgical correction of adolescent idiopathic scoliosis (AIS). However, a precise 3D study of intervertebral deviation has not been previously reported.     

Sagittal balance in scoliosis associated with Marfan syndrome: a stereoradiographic three-dimensional analysis

Purpose Marfan syndrome (MFS) is a genetic disease often marked by the presence of scoliosis. There is no three-dimensional analysis of the deformity in the literature. Our aim was to determine what kind of sagittal balance defines scoliosis associated with MFS, namely a flexion deformity, as it is in scoliosis associated with Chiari I or an extension deformity, as in adolescent idiopathic scoliosis (AIS). To address this issue, we compared the presence or absence of a thoracic scoliosis with the presence or absence of a segment in extension in the thoracic spine. Methods In our series, 30 patients diagnosed with Marfan syndrome were prospectively included. In each patient, personalized three-dimensional reconstruction from T1 to L5 of the spine was made using stereoradiography. The patients were first separated based on the presence or absence of thoracic scoliosis, in order to compare this with the presence or absence of a segment in extension in the thoracic spine. They were then classified into two groups based on the presence or absence of the segment in extension (meaning containing negative values of inter-vertebral sagittal rotation) in the thoracic spine. Results Among scoliotic patients with a thoracic scoliosis (17 cases), there were 13 (76.5% cases) with a segment in extension in the thoracic spine and 4 with no segment in extension. Conclusions Our results showed that scoliosis associated with MFS is somehow original, demonstrating a sagittal balance in extension (as AIS) in about 80% of thoracic curves, but without this characteristic feature in about 20%.     

Breakthrough in three-dimensional scoliosis diagnosis: significance of horizontal plane view and vertebra vectors

Scoliosis is a multifactorial three-dimensional (3D) spinal deformity with integral and directly related vertebral deviations in the coronal, sagittal and horizontal planes. Current classification and diagnostic methods rely on two-dimensional (2D) frontal and lateral X-ray images; no routine methods are available for the visualization and quantitative evaluation of deviations in the horizontal plane. The EOS 2D/3D system presented here is a new, low-dose, orthopedic radiodiagnostic device based on Nobel prize-winning X-ray detection technology with special software for 3D surface reconstruction capabilities that finally led to a breakthrough in scoliosis diagnosis with high-quality, realistic 3D visualization and accurate quantitative parametric analysis. A new concept introducing vertebra vectors and vertebra vector parametric calculations is introduced that furnishes simplified visual and intelligible mathematical information facilitating interpretation of EOS 2D/3D data, especially with regard to the horizontal plane top view images. The concept is demonstrated by a reported scoliotic case that was readily characterized through information derived from vertebra vectors alone, supplemented with the current angulation measurement methods in the coronal and sagittal planes and axial vertebral rotation measurements in the horizontal plane, with a calibrated 3D coordinate system suitable for inter-individual comparisons. The new concept of vertebra vectors may serve as a basis for a truly 3D classification of scoliosis.     

A new system for measuring three-dimensional back shape in scoliosis

The aim of this work was to develop a low-cost automated system to measure the three-dimensional shape of the back in patients with scoliosis. The resulting system uses structured light to illuminate a patient’s back from an angle while a digital photograph is taken. The height of the surface is calculated using Fourier transform profilometry with an accuracy of ±1 mm. The surface is related to body axes using bony landmarks on the back that have been palpated and marked with small coloured stickers prior to photographing. Clinical parameters are calculated automatically and presented to the user on a monitor and as a printed report. All data are stored in a database. The database can be interrogated and successive measurements plotted for monitoring the deformity changes. The system developed uses inexpensive hardware and open source software. Accurate surface topography can help the clinician to measure spinal deformity at baseline and monitor changes over time. It can help the patients and their families to assess deformity. Above all it reduces the dependence on serial radiography and reduces radiation exposure when monitoring spinal deformity.     

二次测量三维CT重建数据在脊柱侧弯矫形术中的应用

目的探讨术前二次测量三维CT重建数据在脊柱侧弯矫形术中的应用和临床意义。方法 2006年8月-2008年3月收治11例重度僵硬型脊柱侧凸患者,男4例,女7例;年龄15～19岁,平均17.2岁。术前在软件操作平台上行二次测量三维CT重建数据,根据测量结果选取入钉点位置,选择合适长度和直径的椎弓根螺钉,按测量角度植入螺钉。共植入197枚螺钉。记录椎弓根螺钉植入时间、术中失血量、术后神经功能状态,测量手术前后矢状面、冠状面Cobb角改变率,术后CT评估螺钉植入的准确性(Andrew分级)。结果椎弓根螺钉植入时间为1～11 min,平均5.8 min;术中失血量为450～2 300 mL,平均1 520 mL。术后1周内复查X线片,冠状面Cobb角矫正率68.5%,矢状面Cobb角矫正率55.5%。术后1周内复查CT扫描显示螺钉位置Ⅰ级77枚(39.1%),Ⅱ级116枚(58.9%),Ⅲ级4枚(2.0%)。11例均获随访,随访时间14个月～2年,无内固定物断裂、移位等并发症以及神经刺激症状发生。结论术前二次测量三维CT重建后的数据为脊柱侧弯患者提供了有效的术中指导,可提高椎弓根植钉准确率和手术安全性。     

Geometric torsion in idiopathic scoliosis: three-dimensional analysis and proposal for a new classification

STUDY DESIGN: Three-dimensionally reconstructed spines of 62 subjects with idiopathic scoliosis were reviewed for three-dimensional pattern classification based on the measurement of geometric torsion. OBJECTIVES: To evaluate the relevance of geometric torsion as a three-dimensional index of scoliosis, and to develop a three-dimensional classification of deformity for idiopathic scoliosis as opposed to the current classifications based on two-dimensional frontal views. SUMMARY OF BACKGROUND DATA: Attempts have been made to measure the geometric torsional shape of scoliotic curves represented curvilinearly. However, the geometric torsion phenomenon has never been properly analyzed and thus has never been precisely defined. METHODS: Standardized stereoradiographs of 62 patients with idiopathic scoliosis were obtained and used to generate three-dimensional reconstructions. A continuous parametric form of the curved line that passes through the vertebrae was created by least square fitting of Fourier series functions. Frenet's formulas then were used to calculate the geometric torsion. RESULTS: Analysis of geometric torsion associated with 94 major scoliotic curves allowed three basic categories of torsion curve patterns to be identified. Scoliotic spines with multiple major curves are described by a combination of basic torsion patterns, one for each curve. CONCLUSIONS: A three-dimensional analysis of the spine in terms of geometric torsion has defined three distinct patterns of torsion in a group of scoliotic curves. Geometric torsion had extreme values at the levels of upper and lower vertebrae, but zero or nearly zero values at the levels of the apices. The torsional phenomenon can be unidirectional or bidirectional in both single and double major curves.     

脊椎共面排列矫形技术治疗特发性脊柱侧凸的初步疗效

目的:评估脊椎共面排列(vertebral coplanar alignment,VCA)矫形技术治疗特发性脊柱侧凸(idiopathicscoliosis,IS)的初步疗效。方法:2010年1月～9月采用VCA技术治疗IS患者20例,男5例,女15例,年龄11～21岁,平均15.3岁;Lenke 1型14例,2型6例;术前主弯Cobb角50°～86°,平均67.5°,柔韧性11.4%～50.9%,平均31.7%;胸椎后凸5°～55°,平均25.7°,按Lenke矢状面形态分,6例为"+",4例为"-",10例为"N"。均采用一期后路椎弓根螺钉固定、VCA矫形、同种异体骨植骨融合治疗。以主胸弯Cobb角评价矫正率,并测定胸椎后凸变化;以顶椎肋骨隆起间距(rib hump,RH)、顶椎椎体肋骨比(apical vertebral body rib ratio,AVB-R)、肋骨弥散间距(apical rib spread difference,ARSD)和椎体旋转角(rotational angle to sacrum,RAsac)评价旋转的矫正情况。结果:所有患者均成功完成矫形手术,手术时间115～196min,平均164min;术中出血400～800ml,平均680ml;未发生严重并发症。术后主弯Cobb角12°～27°,平均20.6°,平均矫正率70.1%;RH、AVB-R、ARSD及RAsac平均矫正率分别为56.3%、29.8%、74.3%和54.1%;术后后凸17°～27°,平均21.8°,术前为"+"或者"-"的患者均矫正为N,无1例发生或残留平背畸形。随访3～12个月,平均9个月,未见矫正丢失和失代偿发生。结论:VCA矫形技术能有效矫正IS患者的冠状面畸形,有效获得或维持胸椎生理性后凸,且具有较好的矫正旋转畸形的能力。     

Pre-, intra-, and postoperative three-dimensional evaluation of adolescent idiopathic scoliosis

The authors measured and compared the pre-, intra-, and postoperative three-dimensional shape of the spine during corrective surgery to quantify the specific contribution of positioning, anesthesia, surgical exposure, surgical instrumentation, and postural adaptation of the thoracic and lumbar spine. In 58 adolescent girls with idiopathic scoliosis undergoing corrective surgery by a posterior approach, the three-dimensional geometry of the thoracic and lumbar spine was documented in the standing position before and after surgery using a three-dimensional reconstruction technique based on multiplanar radiography, and the intraoperative three-dimensional geometry was measured using a three-dimensional magnetic digitizer before and after installation of the first rod. Prone positioning, anesthesia, and surgical exposure are responsible for a considerable decrease in all curves in the frontal and sagittal plane. Instrumentation with the first rod produces additional substantial and favorable three-dimensional changes with partial restoration of the normal sagittal curves and sagittal shift of the plane of maximum deformity. Although no loss of correction was observed in the frontal plane when patients resumed their standing position, a "spring-back" effect on the spine was noted in the sagittal plane and a loss of three-dimensional correction was seen in the orientation of the plane of maximum deformity. Surgeons can use the knowledge of these various changes to achieve better results by more careful attention to the preoperative positioning of patients and to curve correction in the sagittal plane when instrumentation is applied to the spine.     

Morphology of the posteromedial fragment in pertrochanteric fractures: A three-dimensional computed tomography analysis

BackgroundIn this study we describe the morphology of the posteromedial fragment in pertrochanteric fractures using 3D CT scans and answer two questions 1) Do differences exist between the 3D CT appearances of posteromedial fragments and the depictions made in the AO classification 2) Does the posteromedial fragment affect stability in pertrochanteric fractures, in terms of fracture collapse?MethodsPreoperative CT scans of eight 31-A1 and fifty 31-A2 fractures were analysed. The presence of PM fragment, its fragmentation, greater trochanter (GT) involvement, lesser trochanter (LT) fragment size (in terms of its posterior and medial extent as well as LT length), LT fragment displacement (in terms of medial displacement and rotation) were determined. All fractures were treated with a DHS. Fracture collapse was determined on postoperative radiographs. The relationship between fracture collapse and patient factors including age, gender, fracture type (A1 versus A2), characteristics of the posteromedial fragment, and the presence of a lateral wall fracture were determined.ResultsThree out of eight 31-A1 fractures demonstrated a separate GT fragment (three part fracture). Out of the 50 31-A2 fractures, 12 had a single PM fragment, which included the LT and GT in continuity. The more common four part fractures seem to form by further fragmentation of this basic form. In A2 fractures, the GT was almost always broken and the broken fragment comprised a mean 56% of normal GT. The LT fragment involved an average of 74% of the posterior wall, and an average of 36% of the medial wall of the proximal femur. Larger LT fragments were less displaced as compared to smaller fragments. Univariate regression analyses revealed that fracture collapse was significantly correlated with fracture type (A1 versus A2, p 0.036), GT size (p 0.002) and the presence of a lateral wall fracture (p < 0.001).ConclusionsThis study revealed some important differences between the 3D CT appearances and AO classification of pertrochanteric fractures. Further, neither fragmentation of the posteromedial fragment, nor the size of the lesser trochanter fragment was found to predict stability in pertrochanteric fractures. A perioperative lateral wall fracture is the main determinant of stability in these fractures.     

The effects of the three-dimensional deformity of adolescent idiopathic scoliosis on pulmonary function

Purpose

Utilizing 2D measurements, previous studies have found that in AIS, increased thoracic Cobb and decreased thoracic kyphosis contribute to pulmonary dysfunction. Recent technology has improved our ability to measure and understand the true 3D deformity in AIS. The purpose of this study was to evaluate which 3D radiographic measures predict pulmonary dysfunction.

Methods

One hundred and sixty-three surgically treated AIS patients with preoperative PFTs (FEV, FVC, TLC) and EOS^® imaging were identified at a single center. Each spine was reconstructed in 3D to obtain the true coronal, sagittal, and apical rotational deformities. These were then correlated with the patient’s preoperative PFT measurements. Regression analysis was performed to determine the relative effect of each radiographic measure.

Results

There were 124 thoracic and 39 lumbar major curves. The range of preoperative thoracic and lumbar 3D coronal angle was 11–115° and 11–98°, respectively. The range of preoperative thoracic 3D kyphosis (T5–T12) and thoracic apical vertebral rotation was ?56 to 44° and 0–29°, respectively. Increasing thoracic 3D Cobb and thoracic vertebral rotation and decreasing thoracic 3D kyphosis most significantly correlated with decreasing pulmonary function, especially FEV. In patients with the largest degree of thoracic deformity (3D Coronal Cobb > 80°, 3D thoracic lordosis >20°, and absolute apical rotation >25°), the majority of patients had moderate to severe pulmonary impairment (≤65 % predicted). 3D thoracic kyphosis was the most consistent predictor of FEV (r ² = 0.087), FVC (r ² = 0.069), and TLC (r ² = 0.098) impairment.

Conclusions

Larger thoracic coronal, sagittal, and axial deformities increase the risk of pulmonary impairment in patients with AIS. Of these, decreasing 3D thoracic kyphosis is the most consistent predictor. This information can guide surgeons in the decision making process for determining which surgical techniques to utilize and which component of the deformity to focus on.

     

The evolution of three-dimensional technology in musculoskeletal oncology

Musculoskeletal tumours pose considerable challenges for the orthopaedic surgeon during pre-operative planning, resection and reconstruction. Improvements in imaging technology have improved the diagnostic process of these tumours. Despite this, studies have highlighted the difficulties in achieving consistent resection free margins especially in tumours of the pelvis and spine when using conventional methods. Three-dimensional technology – three-dimensional printing and navigation technology – while relatively new, may have the potential to prove useful in the musculoskeletal tumour surgeon's arsenal. Three-dimensional printing (3DP) allows the production of objects by adding material layer by layer rather than subtraction from raw materials as performed conventionally. High resolution imaging, computer tomography (CT) and magnetic resonance imaging (MRI), are used to print highly complex and accurate items. Powder-based printing, vat polymerization-based printing and droplet-based printing are the common 3DP technologies applied. 3DP has been utilized pre-operatively in surgical planning and intra-operatively for patient specific instruments and custom made prosthesis. Pre-operative 3DP models transfer information to the surgeon in a concise yet exhaustive manner. Patient specific instruments are customized 3DP instruments utilized with the intention to easily replicate surgical plans. Complex musculoskeletal tumours pose reconstructive challenges and standard implants are often unable to reconstruct defects satisfactorily. The ability to use custom materials and tailor the pore size, elastic modulus and porosity of the 3DP prosthesis to be comparable to the patient's bone allows for a potential patient-specific prosthesis with unique incorporation and longevity properties. Similarly, navigation technology utilizes CT or MRI images to provides surgeons with real time intraoperative three-dimensional calibration of instruments. It has been shown to potentially allow surgeons to perform more accurate resections. These technological advancements have the potential to greatly impact the management of musculoskeletal tumours. 3D planning models, patient-specific instruments and customized 3DP implants and navigation should not be thought of as separate, but rather, patient-specific adaptation of relevant modes of application should be selected on a case-by-case basis when taking all unique factors of each case into consideration.     

Classification of three-dimensional thoracic deformities in adolescent idiopathic scoliosis from a multivariate analysis

Purpose  

Understanding how to classify and quantify three-dimensional (3D) spinal deformities remains an open question in adolescent idiopathic scoliosis. The objective of this study was to perform a 3D manifold characterization of scoliotic spines demonstrating thoracic deformations using a novel geometric and intuitive statistical tool to determine patterns in pathological cases.