Classification of pediatric lumbosacral spondylolisthesis.

A surgical classification of pediatric lumbosacral spondylolisthesis has been proposed recently. In this classification involving 8 distinct types of spondylolisthesis, the patient is classified according to: 1) the slip grade (low- vs. high-grade), 2) the degree of dysplasia (low- vs.

Relation between the sagittal pelvic and lumbar spine geometries following surgical correction of adolescent idiopathic scoliosis.

Sagittal spinopelvic relations have been reported in adolescent idiopathic scoliosis (AIS), but there is little information on their effect following surgery. The objective of this study is to evaluate the relation between the pelvic and lumbar spine geometries following posterior spinal instrumentation and fusion (PSIF). Sixty patients with AIS undergoing PSIF were studied retrospectively.

Sagittal alignment of the spine and pelvis in the presence of L5-s1 isthmic lysis and low-grade spondylolisthesis.

Study Design: A radiographic study of 82 patients with L5-S1 spondylolysis or spondylolisthesis of less than 50% displacement of L5 on S1.

Objective: To measure and describe the sagittal alignment of the spine and pelvis in patients with spondylolysis before the development of a large secondary deformity associated with progression of the spondylolisthesis.

Summary Of Background Data: Several publications have addressed the alignment of the spine and pelvis as an important factor in the occurrence, symptomatology, progression, and treatment of spondylolysis and spondylolisthesis.

Computerized assessment of sagittal curvatures of the spine: comparison between Cobb and tangent circles techniques.

Objective: The tangent circles technique has been proposed as an alternative to the Cobb angle technique to assess sagittal curves of the spine. However, it has never been compared directly to the Cobb technique. This study compares the reproducibility and clinical relevance of the maximum Cobb angle and tangent circles techniques.

A proposal for a surgical classification of pediatric lumbosacral spondylolisthesis based on current literature.

The classification presented in this paper is the first specifically designed to guide surgical treatment of L5-S1 spondylolisthesis in children and adolescents. It also presents objective criteria to differentiate between low- and high-dysplastic spondylolisthesis and incorporates recent knowledge in the study of sagittal spinopelvic balance. The proposed classification is based on the following: (1) the degree of slip, (2) the degree of dysplasia, and (3) the sagittal spinopelvic balance.

Three-dimensional classification of spinal deformities using fuzzy clustering.

Study Design: A prospective study of a large set of three-dimensional (3D) reconstructions of spinal deformities in adolescent idiopathic scoliosis (AIS).

Objectives: To determine the value of fuzzy clustering techniques to automatically detect clinically relevant 3D curve patterns within this set of 3D spine models.

Summary Of Background Data: Classification is important for the assessment of AIS and has been mainly used to guide surgical treatment.

Variability of spinal instrumentation configurations in adolescent idiopathic scoliosis.

Surgical instrumentation for the correction of adolescent idiopathic scoliosis (AIS) is a complex procedure involving many difficult decisions (i.e. spinal segment to instrument, type/location/number of hooks or screws, rod diameter/length/shape, implant attachment order, amount of rod rotation, etc.

A hierarchical statistical modeling approach for the unsupervised 3-D biplanar reconstruction of the scoliotic spine.

This paper presents a new and accurate three-dimensional (3-D) reconstruction technique for the scoliotic spine from a pair of planar and conventional (postero-anterior with normal incidence and lateral) calibrated radiographic images. The proposed model uses a priori hierarchical global knowledge, both on the geometric structure of the whole spine and of each vertebra. More precisely, it relies on the specification of two 3-D statistical templates.

Sagittal spinopelvic balance in normal children and adolescents.

The sagittal spinopelvic balance is poorly documented in normal pediatric subjects. The purpose of this study is to characterize the sagittal spinopelvic balance in the pediatric population and to evaluate the correlations between spinopelvic parameters. Seven parameters were evaluated from the lateral standing radiographs of 341 normal subjects aged 3-18 years old: thoracic kyphosis (TK), thoracic tilt (TT), lumbar lordosis (LL), lumbar tilt (LT), sacral slope (SS), pelvic tilt (PT) and pelvic incidence (PI).

Optimization of rib surgery parameters for the correction of scoliotic deformities using approximation models.

Background: As opposed to thoracoplasty (a cosmetic surgical intervention used to reduce the rib hump associated with scoliosis), experimental scoliosis has been produced or reversed on animals by rib shortening or lengthening. In a prior work (J. Orthop.

Biomechanical simulations of scoliotic spine correction due to prone position and anaesthesia prior to surgical instrumentation.

Background: The positioning of patients during scoliosis surgery has been shown to affect the scoliosis curve, yet positioning has not been exploited to help improve surgical outcome from a biomechanics point of view. Biomechanical models have been used to study other aspects of scoliosis. The goal of this study is to simulate the specific influence of the prone operative position and anaesthesia using a finite element model with patient personalized material properties.

Complete bilateral agenesis of the ilium in a 7-year-old ambulatory girl: case report.

Study Design: A 7-year-old ambulatory girl with complete bilateral agenesis of the ilium is reported.

Objective: To document the clinical evolution and the spino-pelvic balance of a girl with bilateral agenesis of the ilium.

Summary Of Background Data: Scapuloiliac dysostosis is a rare focal skeletal dysplasia consisting in hypoplasia of ilium and scapula.

The importance of spino-pelvic balance in L5-s1 developmental spondylolisthesis: a review of pertinent radiologic measurements.

Study Design: A review article.

Objectives: The purpose of this article is to review pertinent radiologic measurements for the evaluation of spino-pelvic balance in developmental spondylolisthesis, based on the experience of the Spinal Deformity Study Group.

Summary Of Background Data: Over the past decade, pelvic morphology has been shown to significantly influence spino-pelvic balance of the human trunk in normal and pathologic conditions.

Accuracy assessment of human trunk surface 3D reconstructions from an optical digitising system.

The lack of reliable techniques to follow up scoliotic deformity from the external asymmetry of the trunk leads to a general use of X-rays and indices of spinal deformity. Young adolescents with idiopathic scoliosis need intensive follow-ups for many years and, consequently, they are repeatedly exposed to ionising radiation, which is hazardous to their long-term health. Furthermore, treatments attempt to improve both spinal and surface deformities, but internal indices do not describe the external asymmetry.

A variability study of computerized sagittal spinopelvic radiologic measurements of trunk balance.

Objective: The accurate measurement of spinal and pelvic alignment in the sagittal plane is of prime importance for various disorders. Pelvic incidence (PI) is a fundamental anatomic parameter that is specific and constant for each adult individual and is related to pelvic orientation as well as to the size of lumbar lordosis (LL). It is the summation of the sacral slope (SS) and pelvic tilt (PT), two position-dependent variables that determine pelvic orientation in the sagittal plane.

Analysis of the sagittal balance of the spine and pelvis using shape and orientation parameters.

Objective: The purpose of this study is to introduce a method to analyze and characterize the global sagittal balance of the human trunk using indexes derived from the shape and orientation of the pelvis and cervical, thoracic, and lumbar spine.

Methods: Standing lateral x-rays of a cohort of 160 asymptomatic young adult volunteers were obtained. On each radiograph, a simplified model of the spine and pelvis was created using a dedicated computer software, and the following shape and orientation variables were calculated at each anatomic level: pelvic incidence, pelvic tilt, sacral slope, cervical curvature and tilt, thoracic curvature and tilt, and lumbar curvature and tilt.

Talking about STD/HIV prevention: a look at communication online.

Little is known about the quality and usability of online health information. This analysis evaluated STD prevention websites' content quality and usability. Thirty-six sites were analyzed to determine their adherence to established sexual health guidelines and their accessibility, usability, credibility and currency.

Vertebral wedging characteristic changes in scoliotic spines.

Study Design: A morphometric analysis of vertebral wedging in vertebrae from scoliotic specimens.

Objective: To quantify the vertebral body changes in 30 anatomic specimens affected by a scoliotic deformity.

Summary Of Background Data: Only a few studies have evaluated the exact changes occurring at the level of the vertebral body in scoliotic spines.

Use of a transpedicular drill guide for pedicle screw insertion in the thoracic spine.

A transpedicular drill guide (TDG) was designed to assist in the safe placement of pedicle screws in the thoracic spine. In a preliminary study, pilot holes were drilled into the pedicles (T1 to T12) of eight anatomical models in order to compare the conventional anatomical technique to the TDG. Visual inspection of the drilled pedicles was performed.

Personalized biomechanical modeling of Boston brace treatment in idiopathic scoliosis.

The aim of this study was to describe how the Boston brace modify the scoliotic curvatures using a finite element (FE) model and experimental measurements. The experimental protocol, applied on 12 scoliotic girls, was composed of the pressure measurement at the brace-torso interface followed by two radiographic acquisitions of the patient's torso with and without brace. A 3D FE model of the trunk was built for each unbraced patient.

3D reconstruction and analysis of the whole trunk surface for non-invasive follow-up of scoliotic deformities.

The purpose of this study was to evaluate the 3D reconstruction accuracy of a new technology that allows the acquisition of the whole trunk and to develop a software to analyse the trunk surface asymmetry. A non-invasive active vision system provides a 3D textured reconstruction of the whole trunk. The analysis system provides the clinician with quantitative indices that characterize the whole external trunk asymmetry.

3D biplanar statistical reconstruction of scoliotic vertebrae.

A new 3D reconstruction method of scoliotic vertebrae of a spine, using two calibrated conventional radiographic images (postero-anterior and lateral), and a global prior knowledge on the geometrical structure of each vertebra is presented. This geometrical knowledge is efficiently captured by a statistical deformable template integrating a set of admissible deformations, expressed by the first modes of variation in the Karhunen-Loeve expansion of the pathological deformations observed on a representative scoliotic vertebra population. The proposed reconstruction method consists in fitting the projections of this deformable template with the preliminary segmented contours of the corresponding vertebra on the two radiographic views.

Self-calibration of biplanar radiographs for a retrospective comparative study of the 3D correction of adolescent idiopathic scoliosis.

A novel technique for the 3D reconstruction of the spine from X-ray images is presented. The algorithm is based on the self-calibration of biplanar radiographs. It allows the 3D reconstruction of spines from old uncalibrated preoperative and postoperative radiographs.

A new X-ray calibration/reconstruction system for 3D clinical assessment of spinal deformities.

The main objective of this study was to develop a 3D X-ray reconstruction system of the spine and rib cage for an accurate clinical assessment of spinal deformities. The proposed system uses an explicit calibration technique and a new calibration object composed of: (1) a set of radiopaque markers embedded in a jacket worn by the patient during the X-ray exposures; (2) six control markers to define a reference vertical plane. Computer simulations were performed to evaluate the accuracy of the 3D reconstruction procedure when different kind of displacements were applied on a reference model.