Heterotopic Ossification of Bilateral Hips Post-COVID-19 and Prolonged Immobilization: A Case Report.

Case: A 43-year-old healthy man developed hip pain post-coronavirus disease 2019 (COVID-19) immobilization. Imaging confirmed bilateral bridging heterotopic ossification (HO) of the hips, Brooker Class IV. Bilateral HO caused functional arthrodesis (45° flexion: -20° internal rotation).

A Prospective Cohort Study on Accuracy of Dorsal Tangential Views to Avoid Screw Penetration With Volar Plating of Distal Radius Fractures.

Objective: To assess diagnostic performance of dorsal tangential views (DTVs) to detect dorsal screw protrusion in clinical practice.

Design: Prospective cohort study.

Setting: Level-1 trauma center.

Do 3-D Printed Handheld Models Improve Surgeon Reliability for Recognition of Intraarticular Distal Radius Fracture Characteristics?

Background: For fracture care, radiographs and two-dimensional (2-D) and three-dimensional (3-D) CT are primarily used for preoperative planning and postoperative evaluation. Intraarticular distal radius fractures are technically challenging to treat, and meticulous preoperative planning is paramount to improve the patient's outcome. Three-dimensionally printed handheld models might improve the surgeon's interpretation of specific fracture characteristics and patterns preoperatively and could therefore be clinically valuable; however, the additional value of 3-D printed handheld models for fractures of the distal radius, a high-volume and commonly complex fracture due to its intraarticular configuration, has yet to be determined.

Pt -Catalyzed Hydroxylation of Terminal Aliphatic C(sp )-H Bonds with Molecular Oxygen.

The practical application of Shilov-type Pt catalysis to the selective hydroxylation of terminal aliphatic C-H bonds remains a formidable challenge, due to difficulties in replacing Pt with a more economically viable oxidant, particularly O . We report the potential of employing FeCl as a suitable redox mediator to overcome the kinetic hurdles related to the direct use of O in the Pt reoxidation. For the selective conversion of butyric acid to γ-hydroxybutyric acid (GHB), a significantly enhanced catalyst activity and stability (turnover numbers (TON)>30) were achieved under 20 bar O in comparison to current state-of-the-art systems (TON<10).

Do Stem Design and Surgical Approach Influence Early Aseptic Loosening in Cementless THA?

Background: Some studies have revealed an increased risk of early aseptic loosening of cementless stems in THA when inserted through an anterior or anterolateral approach compared with a posterior approach, whereas approach does not appear to be a risk factor in others. Stem design, whether "anatomic" (that is, stems with a curved lateral profile or an obtuse angle at the proximal-lateral portion of the stem) or "shoulder" (that is, straight with a proximal shoulder), may also be associated with a differential risk of aseptic loosening in cementless THA depending on the surgical approach used, but if so, this risk is not well characterized.

Questions/purposes: In this national registry study, we investigated the association between surgical approach and early aseptic loosening of (1) cementless femoral stems with a proximal angular shape (shoulder); and (2) anatomically shaped femoral stems.

Kinematic Magnetic Resonance Imaging Assessment of the Degenerative Cervical Spine: Changes after Anterior Decompression and Cage Fusion.

 A prospective cohort study.  Decompression and fusion of cervical vertebrae is a combined procedure that has a high success rate in relieving radicular symptoms and stabilizing or improving cervical myelopathy. However, fusion may lead to increased motion of the adjacent vertebrae and cervical deformity.

Evolution of the ischio-iliac lordosis during natural growth and its relation with the pelvic incidence.

Purpose: Human fully upright ambulation, with fully extended hips and knees, and the body's center of gravity directly above the hips, is unique in nature, and distinguishes humans from all other mammalians. This bipedalism is made possible by the development of a lordosis between the ischium and ilium; it allows to ambulate in this unique bipedal manner, without sacrificing forceful extension of the legs. This configuration in space introduces unique biomechanical forces with relevance for a number of spinal conditions.

Evaluation of pelvic morphology in the sagittal plane.

Background Context: It is generally accepted that for normal subjects the angle of pelvic incidence (PI) increases during childhood and then remains unchanged throughout adolescence and adulthood. However, recent findings show that PI increases linearly throughout the lifespan due to morphological changes of the pelvis.

Purpose: A retrospective study aiming to determine the extent of morphological changes of the pelvis related to the age of the subjects.

Quantitative analysis of the closure pattern of the neurocentral junction as related to preexistent rotation in the normal immature spine.

Background Context: The normal spine is not a symmetrical structure. In recent studies, we demonstrated the presence of an axial rotational pattern that is similar to what is seen in the most prevalent curve patterns in idiopathic scoliosis at different ages. This suggests that if the spine starts to decompensate into scoliosis, it follows this preexistent rotational pattern.

Sagittal spinal profile and spinopelvic balance in parents of scoliotic children.

Background Context: It is well known that spinal biomechanics and familial predisposition play an important role in the onset and evolution of idiopathic scoliosis. The relationship between the sagittal profile of the spine and spinal biomechanics has also been established in a number of studies. It has been suggested previously that a certain sagittal spinal configuration with implications for spinal rotational stiffness is inherited, thus providing a possible explanation for the well-known hereditary component in adolescent idiopathic scoliosis (AIS).

Posteriorly directed shear loads and disc degeneration affect the torsional stiffness of spinal motion segments: a biomechanical modeling study.

Study Design: Finite element study.

Objective: To analyze the effects of posterior shear loads, disc degeneration, and the combination of both on spinal torsion stiffness.

Summary Of Background Data: Scoliosis is a 3-dimensional deformity of the spine that presents itself mainly in adolescent girls and elderly patients.

A review of methods for evaluating the quantitative parameters of sagittal pelvic alignment.

Background Context: The sagittal alignment of the pelvis represents the basic mechanism for maintaining postural equilibrium, and a number of methods were developed to assess normal and pathologic pelvic alignments from two-dimensional sagittal radiographs in terms of positional and anatomic parameters.

Purpose: To provide a complete overview of the existing methods for quantitative evaluation of sagittal pelvic alignment and summarize the relevant publications.

Study Design: Review article.

Analysis of pelvic incidence from 3-dimensional images of a normal population.

Study Design: Pelvic incidence (PI) was measured in 3 dimensions from computed tomographic (CT) images of normal subjects using a computerized method.

Objective: To obtain the angle of PI from 3-dimensional (3D) images and analyze its distribution in a normal population.

Summary Of Background Data: The sagittal alignment of the pelvis is usually evaluated in 2-dimensional (2D) sagittal radiographs.

Platelet pool inventory management: theory meets practice.

Background: The shelf life of platelet concentrates (PCs) is a matter of days. Simultaneously, the demand is highly variable, shortages are not allowed, and producing too many results in outdating. Concurrently, younger PCs, implying an extended time till outdating (TTO), are preferred.

Experimental animal models in scoliosis research: a review of the literature.

Background Context: Many animal species and an overwhelming variety of procedures that produce an experimental scoliosis have been reported in the literature. However, varying results have been reported on identical procedures in different animal species. Furthermore, the relevance of experimental animal models for the understanding of human idiopathic scoliosis remains questionable.

Analysis of preexistent vertebral rotation in the normal infantile, juvenile, and adolescent spine.

Study Design: Vertebral rotation was systematically analyzed in the normal, nonscoliotic thoracic spine of children aged 0 to 16 years. Subgroups were created to match the infantile, juvenile, and adolescent age groups according to the criteria of the Scoliosis Research Society.

Objective: To determine whether a distinct pattern of vertebral rotation in the transverse plane exists in the normal, nonscoliotic infantile, juvenile, and adolescent spine.

The role of posteriorly directed shear loads acting on a pre-rotated growing spine: a hypothesis on the pathogenesis of idiopathic scoliosis.

Despite years of extensive research, the etiology of idiopathic scoliosis still has not been resolved. A hypothesis on the role of posteriorly directed shear loads was studied in several biomechanical and imaging studies. So far, it has been shown that: on the human erect spine these posteriorly directed shear loads act; these loads decrease the rotational stability of the spine vitro and in vivo; once rotation occurs, it logically follows an already built-in vertebral rotational pattern, that is pre-existent in the human spine; this pre-existent rotational pattern is related to organ anatomy, and not to handedness; certain areas in the female spine are more subject to posteriorly directed shear loads as certain areas in the female spine are more backwardly inclined.

Pre-existent vertebral rotation in the human spine is influenced by body position.

Human bipedalism appears to be a prerequisite for the development of idiopathic scoliosis. The objective of this study was to examine the effect of different positions of the human spine on vertebral rotation in vivo. Thirty asymptomatic volunteers underwent MRI scanning of the spine in three different body positions; upright, quadrupedal-like and supine.

Pre-existent vertebral rotation in the human spine is influenced by body position.

Both the humans as well as the quadrupedal spine have been shown to exhibit a pattern of pre-existent rotation that is similar in direction to what is found in the most common types of idiopathic scoliosis. It has been postulated that human bipedalism introduces forces to the spine that increase a tendency of the vertebrae to rotate. The objective of this study was to examine the effect of body position on vertebral rotation in vivo.

Differences in male and female spino-pelvic alignment in asymptomatic young adults: a three-dimensional analysis using upright low-dose digital biplanar X-rays.

Study Design: A three-dimensional analysis of spino-pelvic alignment in 60 asymptomatic young adult males and females.

Objectives: To analyze the differences in sagittal spino-pelvic alignment in a group of asymptomatic young adult males and females and describe gender specific reference values.

Summary Of Background Data: Several spinal disorders like idiopathic scoliosis and Scheuermann's disease have a well-known sex-related prevalence ratio.

Relationship of serotonergic antidepressants and need for blood transfusion in orthopedic surgical patients.

Background: Several reports of various bleeding problems associated with the use of serotonergic antidepressants have been published. However, no information concerning the effect of these drugs on perioperative blood loss and blood transfusion requirements during orthopedic surgery is available. The objective of this study was to determine the association between use of serotonergic antidepressants and perioperative blood loss and transfusion in orthopedic surgical patients.