A high-quality reference genome of the kelp surfperch, Brachyistius frenatus (Embiotocidae), a wide-ranging Eastern Pacific reef fish with no pelagic larval stage.

The surfperches (family Embiotocidae) are a unique group of mostly marine fishes whose phylogenetic position within the Ovalentaria clade (Percomorpha) is still unresolved. As a result of their viviparity and lack of a dispersive larval stage, surfperches are an excellent model for the study of speciation, gene flow, and local adaptation in the ocean. They are also the target of an immensely popular recreational fishery.

Upwelling-level acidification and pH/pCO variability moderate effects of ocean acidification on brain gene expression in the temperate surfperch, Embiotoca jacksoni.

Acidification-induced changes in neurological function have been documented in several tropical marine fishes. Here, we investigate whether similar patterns of neurological impacts are observed in a temperate Pacific fish that naturally experiences regular and often large shifts in environmental pH/pCO . In two laboratory experiments, we tested the effect of acidification, as well as pH/pCO variability, on gene expression in the brain tissue of a common temperate kelp forest/estuarine fish, Embiotoca jacksoni.

Reference Genome of the Black Surfperch, Embiotoca jacksoni (Embiotocidae, Perciformes), a California Kelp Forest Fish That Lacks a Pelagic Larval Stage.

Surfperches (Family Embiotocidae) are viviparous temperate reef fishes that brood their young. This life history trait translates into limited dispersal, strong population structure, and an unusually strong potential for local adaptation in a marine fish. As part of the California Conservation Genomics Project (CCGP), we sequenced the genome of the Black Surfperch, Embiotoca jacksoni, to establish a genomic model for understanding phylogeographic patterns of marine organisms in California.

Emergent effects of global change on consumption depend on consumers and their resources in marine systems.

A better understanding of how environmental change will affect species interactions would significantly aid efforts to scale up predictions of near-future responses to global change from individuals to ecosystems. To address this need, we used meta-analysis to quantify the individual and combined effects of ocean acidification (OA) and warming on consumption rates of predators and herbivores in marine ecosystems. Although the primary studies demonstrated that these environmental variables can have direct effects on consumers, our analyses highlight high variability in consumption rates in response to OA and warming.

Volar and Dorsal Blood Supply to the Lunate: A Cadaveric Study.

Although various studies have proposed vascular and mechanical factors, the etiology of Kienböck disease is unknown. Kienböck theorized that lunatomalacia resulted from traumatic disruption of blood supply and bony nutrition to the lunate. Extraosseous supply to the lunate, as far as volar or dorsal vessels are concerned, is still controversial.

Ecological change in dynamic environments: Accounting for temporal environmental variability in studies of ocean change biology.

The environmental conditions in the ocean have long been considered relatively more stable through time compared to the conditions on land. Advances in sensing technologies, however, are increasingly revealing substantial fluctuations in abiotic factors over ecologically and evolutionarily relevant timescales in the ocean, leading to a growing recognition of the dynamism of the marine environment as well as new questions about how this dynamism may influence species' vulnerability to global environmental change. In some instances, the diurnal or seasonal variability in major environmental change drivers, such as temperature, pH and seawater carbonate chemistry, and dissolved oxygen, can exceed the changes expected with continued anthropogenic global change.

Cervicothoracic Pedicle Morphometry: Using an Osteological Collection to Characterize Trends in Pedicle Size.

Pedicle screws are a common treatment option for spinal instability. Despite their popularity, pedicle screws carry the risk of transpedicular violation with subsequent neural and vascular damage. This study measured the pedicle dimensions of 500 dry specimens in an osteological collection.

Experimental evaluation of current and novel approximations of articular surfaces of the ankle joint.

Kinematics and flexibility properties of both natural and replaced ankle joints are affected by the geometry of the articulating surfaces. Recent studies proposed an original saddle-shaped, skewed, truncated cone with laterally oriented apex, as tibiotalar contact surfaces for ankle prosthesis. The goal of this study was to compare in vitro this novel design with traditional cylindrical or medially centered conic geometries in terms of their ability to replicate the natural ankle joint mechanics.

Experimental evaluation of a new morphological approximation of the articular surfaces of the ankle joint.

The mechanical characteristics of the ankle such as its kinematics and load transfer properties are influenced by the geometry of the articulating surfaces. A recent, image-based study found that these surfaces can be approximated by a saddle-shaped, skewed, truncated cone with its apex oriented laterally. The goal of this study was to establish a reliable experimental technique to study the relationship between the geometry of the articular surfaces of the ankle and its mobility and stability characteristics and to use this technique to determine if morphological approximations of the ankle surfaces based on recent discoveries, produce close to normal behavior.

Spondylolysis and End Plate Arthrosis at L5-S1: A Cadaveric Study.

This study examined the effect of bilateral and unilateral L5 pars defects on the degree of disk degeneration at the L5-S1 level in cadaveric specimens. An observational study was performed of 690 cadaveric specimens selected at random. These specimens represent individuals who died between 1893 and 1938.

Calcaneocuboid Joint Arthritis of the Midfoot Precedes Tibiotalar Joint Arthritis.

Surgical models have best shown the relationship between ankle and mid-foot osteoarthritis, although findings regarding the calcaneocuboid joint have varied. To the authors' knowledge, no studies have evaluated the relationship between degenerative changes across the tibiotalar and calcaneocuboid joints. The goal of this study was to determine whether such a relationship exists and which joint degenerates first.

Most 30-day Readmissions After Anterior Cervical Discectomy and Fusion Are Not Due to Surgical Site-Related Issues: An Analysis of 17,088 Patients.

Study Design: A retrospective study of patients undergoing anterior cervical discectomy and fusion (ACDF) in the prospective National Surgical Quality Improvement Program (NSQIP) database.

Objective: To determine the most common reasons for readmission within 30 days after elective ACDF.

Summary Of Background Data: ACDF is a commonly performed surgery that is safe and effective for treating a variety of cervical spine pathologies.

Bilateral Pars Defects at the L4 Vertebra Result in Increased Degeneration When Compared With Those at L5: An Anatomic Study.

Background: Cadaveric studies have examined disc degeneration at the L4-L5 and L5-S1 motion segments; however, we are not aware of another study that has examined the relationship between bilateral spondylolysis and its effect on degenerative disc disease at those levels. This may have been overlooked by researchers owing to the majority of spondylolysis occurring at the L5 vertebra.

Questions/purposes: Using osteologic specimens from a collection that included individuals who died in one city in the USA between 1893 and 1938, we asked: (1) do specimens with bilateral spondylolysis (bilateral pars defects) have increased levels of disc degeneration, at their respective motion segments, when compared with matched controls without spondylolysis, and (2) is the finding of a bilateral pars defect associated with more severe arthritis at L4-L5 than at L5-S1?

Methods: An observational study was performed on 665 skeletal lumbar spines from the Hamann-Todd Osteologic Collection at the Cleveland Museum of Natural History (Cleveland, OH, USA).

Length of Stay and Readmission After Total Shoulder Arthroplasty: An Analysis of 1505 Cases.

We conducted a study to characterize the risk factors for extended length of stay (LOS) and readmission after primary total shoulder arthroplasty (TSA). Patients who were 60 years or older and underwent TSA between 2011 and 2012 were identified from the American College of Surgeons National Surgical Quality Improvement Program database. Bivariate and multivariate analyses were used to test patient characteristics for association with extended LOS and readmission within 30 days.

Pedicle Morphometry of Lumbar Vertebrae: Male, Taller, and Heavier Specimens Have Bigger Pedicles.

Study Design: An anatomic study of pedicle dimensions was performed for lumbar vertebrae from American subjects.

Objective: To quantify the dimensions of the lumbar pedicles and to better define the demographic factors that could ultimately govern the caliber selection of pedicle screws.

Summary Of Background Data: Transpedicular screw fixation allows for segmental instrumentation into multiple vertebrae across multilevel fusion area, offering considerable biomechanical advantage over the conventional hook and lateral mass fixation.

Undertapping of Lumbar Pedicle Screws Can Result in Tapping With a Pitch That Differs From That of the Screw, Which Decreases Screw Pullout Force.

Study Design: Survey of spine surgeons and biomechanical comparison of screw pullout forces.

Objective: To investigate what may be a suboptimal practice regularly occurring in spine surgery.

Summary Of Background Data: In order for a tap to function in its intended manner, the pitch of the tap should be the same as the pitch of the screw.

Lumbar degenerative disc disease and tibiotalar joint arthritis: a 710-specimen postmortem study.

Research has associated lumbar spinal disease with lower extremity arthrosis. These studies focused solely on the lumbar spine's connection with hip or knee pathology, failing to investigate potential ankle relationships. We specifically explored the interplay between lumbar disc degeneration and tibiotalar joint arthritis.

General compared with spinal anesthesia for total hip arthroplasty.

Background: Total hip arthroplasty may be performed under general or spinal anesthesia. The purpose of the current study was to compare perioperative outcomes between anesthetic types for patients undergoing primary elective total hip arthroplasty.

Methods: Patients who had undergone primary elective total hip arthroplasty from 2010 to 2012 were identified from the American College of Surgeons National Surgical Quality Improvement Program database.

Lower thoracic pedicle morphometry: male, taller, and heavier specimens have bigger pedicles.

Study Design: An anatomic study of pedicle dimensions was performed for lower thoracic vertebrae from American human subjects.

Objective: To quantify the dimensions of the lower thoracic pedicles and to better define the demographic factors that could ultimately govern the caliber selection of pedicle screws.

Summary Of Background Data: Transpedicular screw fixation allows for segmental instrumentation into multiple vertebrae across multilevel fusion area, offering considerable biomechanical advantage over the conventional hook and lateral mass fixation.

Morbidity, mortality, and readmission after vertebral augmentation: analysis of 850 patients from the American College of Surgeons National Surgical Quality Improvement Program database.

Study Design: Retrospective cohort study.

Objective: To identify risk factors for poor short-term outcomes after vertebral augmentation procedures.

Summary Of Background Data: Vertebral compression fractures are the most common fractures of osteoporosis and are frequently treated with vertebroplasty or kyphoplasty.

Use of an operating microscope during spine surgery is associated with minor increases in operating room times and no increased risk of infection.

Study Design: Retrospective database review.

Objective: To evaluate whether microscope use during spine procedures is associated with increased operating room times or increased risk of infection.

Summary Of Background Data: Operating microscopes are commonly used in spine procedures.

Pedicle morphometry of upper thoracic vertebrae: an anatomic study of 503 cadaveric specimens.

Study Design: An anatomic study of pedicle dimensions was performed for upper thoracic vertebrae from American human subjects.

Objective: To quantify the dimensions of the upper thoracic pedicles and to better define the demographic factors that could ultimately govern the caliber selection of pedicle screws.

Summary Of Background Data: Transpedicular screw fixation allows for segmental instrumentation into multiple vertebrae across multilevel fusion area, offering considerable biomechanical advantage over the conventional hook and lateral mass fixation.

Anterior ankle impingement: diagnosis and treatment.

Anterior ankle impingement is a common clinical condition characterized by chronic anterior ankle pain that is exacerbated on dorsiflexion. Additional symptoms include instability; limited ankle motion; and pain with squatting, sprinting, stair climbing, and hill climbing. Diagnosis is typically confirmed with plain radiographs.

Osteochondritis dissecans of the talus: diagnosis and treatment in athletes.

Osteochondritis dissecans of the talus is a subset of osteochondral lesions of the talus that also includes osteochondral fractures, avascular necrosis, and degenerative arthritis. Osteochondral lesions of the talus can be associated with injury to the ankle. This article discusses the anatomy, pathoanatomy, history, physical examination, imaging, management algorithm, and outcomes of surgical treatment of osteochondral lesions in these patients.

The Clinical Biomechanics Award 2013 -- presented by the International Society of Biomechanics: new observations on the morphology of the talar dome and its relationship to ankle kinematics.

Background: Ankle passive kinematics is determined primarily by articular surface morphology and ligament constraints. Previous morphological studies concluded that the talar dome can be approximated by a truncated cone, whose apex is directed medially and whose major axis is the axis of rotation of the ankle. This and other functional morphology concepts were evaluated in this study whose goal was to describe and quantify the 3D morphology of the talus using 3D image-based bone models and engineering software tools.