Ten technical aspects of baseplate fixation in reverse total shoulder arthroplasty for patients without glenoid bone loss: a systematic review.

The aim of this systematic review was to collect evidence on the following 10 technical aspects of glenoid baseplate fixation in reverse total shoulder arthroplasty (rTSA): screw insertion angles; screw orientation; screw quantity; screw length; screw type; baseplate tilt; baseplate position; baseplate version and rotation; baseplate design; and anatomical safe zones. Five literature libraries were searched for eligible clinical, cadaver, biomechanical, virtual planning, and finite element analysis studies. Studies including patients >16 years old in which at least one of the ten abovementioned technical aspects was assessed were suitable for analysis.

Convex-concave and anterior-posterior spinal length discrepancies in adolescent idiopathic scoliosis with major right thoracic curves versus matched controls.

Purpose: The apical deformation in adolescent idiopathic scoliosis (AIS) is a combination of rotation, coronal deviation and passive anterior lengthening of the spine. In AIS surgery, posterior-concave lengthening or anterior-convex shortening can be part of the corrective maneuver, as determined by the individual surgeon's technique. The magnitude of convex-concave and anterior-posterior length discrepancies, and how this needs to be modified to restore optimal spinal harmony, remains unknown.

Cross-validation of ultrasound imaging in adolescent idiopathic scoliosis.

Purpose: Adolescent idiopathic scoliosis (AIS) patients are exposed to 9-10 times more radiation and a fivefold increased lifetime cancer risk. Radiation-free imaging alternatives are needed. Ultrasound imaging of spinal curvature was shown to be accurate, however, systematically underestimating the Cobb angle.

Anterior lengthening in scoliosis occurs only in the disc and is similar in different types of scoliosis.

Background Context: Relative anterior spinal overgrowth was proposed as a generalized growth disturbance and a potential initiator of adolescent idiopathic scoliosis (AIS). However, anterior lengthening has also been observed in neuromuscular (NM) scoliosis and was shown to be restricted to the apical areas and located in the intervertebral discs, not in the bone. This suggests that relative anterior spinal overgrowth does not rightfully describe anterior lengthening in scoliosis, as it seems not a generalized active growth phenomenon, nor specific to AIS.

A computed tomography-based spatial reference for pedicle screw placement in adolescent idiopathic scoliosis.

Study Design: Cross-sectional.

Objectives: To determine semiautomatically the 3D position of the pedicle axis in operative adolescent idiopathic scoliosis (AIS) patients relative to the operating table and the lamina, as orientation for pedicle screw placement for better understanding and reference of spine surgeons. Pedicle morphology is well described as the angle between the convex and concave pedicle.

CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis.

Purpose: To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity.

Methods: Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°-109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local mechanical torsion for each spinal level, using previously validated image processing techniques.

Results: For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine.

Natural course of scoliosis and lifetime risk of scoliosis surgery in spinal muscular atrophy.

Objective: To investigate the natural course of scoliosis and to estimate lifetime probability of scoliosis surgery in spinal muscular atrophy (SMA).

Methods: We analyzed cross-sectional data from 283 patients from our population-based cohort study. Additional longitudinal data on scoliosis progression and spinal surgery were collected from 36 consecutive patients who received scoliosis surgery at our center.

Surgical Outcomes of Anterior Versus Posterior Fusion in Lenke Type 1 Adolescent Idiopathic Scoliosis.

Study Design: Retrospective study.

Objective: To describe surgical results in two and three dimensions and patient-reported outcomes of scoliosis treatment for Lenke type 1 idiopathic curves with an open anterior or posterior approach.

Summary Of Background Data: Different surgical techniques have been described to prevent curve progression and to restore spinal alignment in idiopathic scoliosis.

The Changing Position of the Center of Mass of the Thorax During Growth in Relation to Pre-existent Vertebral Rotation.

Study Design: Cross-sectional.

Objective: The aim of this study was to analyze the thoracic center of mass (COM) position of children at different ages and evaluate its relation with the previously reported pre-existent rotational pattern of the normal spine.

Summary Of Background Data: The normal, nonscoliotic thoracic spine is known to have a rotational pattern that changes direction during growth, a transition from left-sided toward right-sided rotation with increasing age.

Three-dimensional pelvic incidence is much higher in (thoraco)lumbar scoliosis than in controls.

Purpose: The pelvic incidence (PI) is used to describe the sagittal spino-pelvic alignment. In previous studies, radiographs were used, leading to less accuracy in establishing the three-dimensional (3D) spino-pelvic parameters. The purpose of this study is to analyze the differences in the 3D sagittal spino-pelvic alignment in adolescent idiopathic scoliosis (AIS) subjects and non-scoliotic controls.

Anterior-posterior length discrepancy of the spinal column in adolescent idiopathic scoliosis-a 3D CT study.

Background Context: One of the characteristics of reported observations in adolescent idiopathic scoliosis (AIS) is that the thoracic spine is longer anteriorly than posteriorly, more pronounced around the apex than the transitional zones. This reversal of the normal kyphotic anatomy of the thoracic spine is related to questions of etiopathogenesis of AIS. The changes in the anatomy of the anterior column have been described rather in detail; however, the role of the posterior spinal column and the laminae has so far not been elucidated.

Scoliosis in association with the 22q11.2 deletion syndrome: an observational study.

Objective: The 22q11.2 deletion syndrome (22q11.2DS) is the most common microdeletion syndrome in humans.

A reliability and validity study for different coronal angles using ultrasound imaging in adolescent idiopathic scoliosis.

Background Context: Radiation exposure remains a big concern in adolescent idiopathic scoliosis (AIS). Ultrasound imaging of the spine could significantly reduce or possibly even eliminate this radiation hazard. The spinous processes (SPs) and transverse processes (TPs) were used to measure the coronal deformity.

What Is the Actual 3D Representation of the Rib Vertebra Angle Difference (Mehta Angle)?

Study Design: Cross-sectional study.

Objective: To establish the relevance of the conventional two-dimensional (2D) rib vertebra angle difference (RVAD) and the relationship with the complex three-dimensional (3D) apical morphology in scoliosis.

Summary Of Background Data: The RVAD, also known as Mehta angle, describes apical rib asymmetry on conventional radiographs and was introduced as a prognostic factor for curve severity in early onset scoliosis, and later applied to other types of scoliosis as well.

The Height-Width-Depth Ratios of the Intervertebral Discs and Vertebral Bodies in Adolescent Idiopathic Scoliosis vs Controls in a Chinese Population.

Adolescent idiopathic scoliosis (AIS) patients have been reported to be taller and more slender than normal controls, suggesting less mechanical stiffness of their trunk and spine. For assessment of mechanical stiffness, to our best knowledge this is the first to study height-width-depth relations at the level of the individual vertebra and disc in 3-D and to evaluate its relation with the Cobb angle severity. A unique series of high-resolution pre-operative computed tomographic (CT) scans of a total of 105 Chinese patients with moderate to severe AIS and 11 age-matched non-scoliotic controls were used for this study.

Upright, prone, and supine spinal morphology and alignment in adolescent idiopathic scoliosis.

Background: Patients with adolescent idiopathic scoliosis (AIS) are usually investigated by serial imaging studies during the course of treatment, some imaging involves ionizing radiation, and the radiation doses are cumulative. Few studies have addressed the correlation of spinal deformity captured by these different imaging modalities, for which patient positioning are different. To the best of our knowledge, this is the first study to compare the coronal, axial, and sagittal morphology of the scoliotic spine in three different body positions (upright, prone, and supine) and between three different imaging modalities (X-ray, CT, and MRI).

Asymmetry of the Vertebral Body and Pedicles in the True Transverse Plane in Adolescent Idiopathic Scoliosis: A CT-Based Study.

Study Design: Cross-sectional.

Objectives: To quantify the asymmetry of the vertebral bodies and pedicles in the true transverse plane in adolescent idiopathic scoliosis (AIS) and to compare this with normal anatomy.

Summary Of Background Data: There is an ongoing debate about the existence and magnitude of the vertebral body and pedicle asymmetry in AIS and whether this is an expression of a primary growth disturbance, or secondary to asymmetrical loading.

Anterior Spinal Overgrowth Is the Result of the Scoliotic Mechanism and Is Located in the Disc.

Study Design: Cross-sectional study.

Objective: To investigate the presence and magnitude of anterior spinal overgrowth in neuromuscular scoliosis and compare this with the same measurements in idiopathic scoliosis and healthy spines.

Summary Of Background Data: Anterior spinal overgrowth has been described as a potential driver for the onset and progression of adolescent idiopathic scoliosis (AIS).