The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview

The Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM) is a dedicated multi-object RM experiment that has spectroscopically monitored a sample of 849 broad-line quasars in a single 7 deg$^2$ field with the SDSS-III BOSS spectrograph. The RM quasar sample is flux-limited to i_psf=21.7 mag, and covers a redshift range of 0.1<z<4.5. Optical spectroscopy was performed during 2014 Jan-Jul dark/grey time, with an average cadence of ~4 days, totaling more than 30 epochs. Supporting photometric monitoring in the g and i bands was conducted at multiple facilities including the CFHT and the Steward Observatory Bok telescopes in 2014, with a cadence of ~2 days and covering all lunar phases. The RM field (RA, DEC=14:14:49.00, +53:05:00.0) lies within the CFHT-LS W3 field, and coincides with the Pan-STARRS 1 (PS1) Medium Deep Field MD07, with three prior years of multi-band PS1 light curves. The SDSS-RM 6-month baseline program aims to detect time lags between the quasar continuum and broad line region (BLR) variability on timescales of up to several months (in the observed frame) for ~10% of the sample, and to anchor the time baseline for continued monitoring in the future to detect lags on longer timescales and at higher redshift. SDSS-RM is the first major program to systematically explore the potential of RM for broad-line quasars at z>0.3, and will investigate the prospects of RM with all major broad lines covered in optical spectroscopy. SDSS-RM will provide guidance on future multi-object RM campaigns on larger scales, and is aiming to deliver more than tens of BLR lag detections for a homogeneous sample of quasars. We describe the motivation, design and implementation of this program, and outline the science impact expected from the resulting data for RM and general quasar science.Comment: 25 pages, submitted to ApJS; project website at http://www.sdssrm.or

Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

Management of Orthopedic Blast Injuries

Over the past two decades, the complexity and severity of orthopedic blast injuries have increased significantly. This has been the case not only with the combat operations undertaken in Iraq and Afghanistan but also with casualties sustained in terrorist attacks around the globe. Multiple, high-energy extremity injuries are the predominate injury patterns in these scenarios. With greater experience and understanding of these injury patterns, orthopedic management of the blast injury patient has significantly evolved over this time frame. From the initial resuscitation of the patient in the emergency department (ED), to the advent of damage control orthopedics, to the definitive reconstructive care of these patients’ injuries, the evolution in understanding how to properly treat these injuries has led to substantially improved outcomes. As knowledge of how to treat these complex injuries continues to evolve, there has been dramatic improvement in the management of the long-term sequela of these injuries such as infection, heterotopic ossification, chronic pain, PTSD, and functional outcome

Gun Barrel View of the Anterior Pelvic Ring for Percutaneous Anterior Column or Superior Pubic Ramus Screw Placement

Background Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring. Methods Twenty retrograde anterior pelvic ring screws were percutaneously placed in ten cadaveric specimens. Arranging a standard C-arm in a position similar to obtaining a lateral hip image, with angles of 54° ± 2° beam to body, 75° ± 5° of reverse cantilever and 14° ± 6° of outlet, a gun barrel view of the anterior pelvic ring is identified. Fluoroscopic images were taken, and the hemipelvi were harvested to examine the dimensions of the anterior pelvic ring and inspected for any cortical or articular perforation. Results The minimum cranial-to-caudal distance in the anterior pelvic ring was 9 mm (range 6.5–12 mm), and the minimum anterior-to-posterior dimension was 9 mm (range 5–15 mm). All but 2 screws were completely confined within the osseous corridors. Identifiable on final fluoroscopic evaluation, one screw perforated the psoas groove and a second perforated the acetabular dome. Overall, 90 % of our screws were accurately and safely placed, upon the first attempt, within the anterior pelvic ring using the described gun barrel view. Conclusion Employing either open reduction, or following a closed or percutaneous reduction, the anterior pelvic ring gun barrel view can reproducibly guide safe placement of anterior pelvic ring screw fixation

Gun Barrel View of the Anterior Pelvic Ring for Percutaneous Anterior Column or Superior Pubic Ramus Screw Placement

Background Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring. Methods Twenty retrograde anterior pelvic ring screws were percutaneously placed in ten cadaveric specimens. Arranging a standard C-arm in a position similar to obtaining a lateral hip image, with angles of 54° ± 2° beam to body, 75° ± 5° of reverse cantilever and 14° ± 6° of outlet, a gun barrel view of the anterior pelvic ring is identified. Fluoroscopic images were taken, and the hemipelvi were harvested to examine the dimensions of the anterior pelvic ring and inspected for any cortical or articular perforation. Results The minimum cranial-to-caudal distance in the anterior pelvic ring was 9 mm (range 6.5–12 mm), and the minimum anterior-to-posterior dimension was 9 mm (range 5–15 mm). All but 2 screws were completely confined within the osseous corridors. Identifiable on final fluoroscopic evaluation, one screw perforated the psoas groove and a second perforated the acetabular dome. Overall, 90 % of our screws were accurately and safely placed, upon the first attempt, within the anterior pelvic ring using the described gun barrel view. Conclusion Employing either open reduction, or following a closed or percutaneous reduction, the anterior pelvic ring gun barrel view can reproducibly guide safe placement of anterior pelvic ring screw fixation

Gun Barrel View of the Anterior Pelvic Ring for Percutaneous Anterior Column or Superior Pubic Ramus Screw Placement

Background Traditionally, operative fixation of pelvic and acetabular injuries involves complex approaches and significant complications. Accelerated rehabilitation, decreased soft tissue stripping and decreased wound complications are several benefits driving a recent interest in percutaneous fixation. We describe a new fluoroscopic view to guide the placement of screws within the anterior pelvic ring. Methods Twenty retrograde anterior pelvic ring screws were percutaneously placed in ten cadaveric specimens. Arranging a standard C-arm in a position similar to obtaining a lateral hip image, with angles of 54° ± 2° beam to body, 75° ± 5° of reverse cantilever and 14° ± 6° of outlet, a gun barrel view of the anterior pelvic ring is identified. Fluoroscopic images were taken, and the hemipelvi were harvested to examine the dimensions of the anterior pelvic ring and inspected for any cortical or articular perforation. Results The minimum cranial-to-caudal distance in the anterior pelvic ring was 9 mm (range 6.5–12 mm), and the minimum anterior-to-posterior dimension was 9 mm (range 5–15 mm). All but 2 screws were completely confined within the osseous corridors. Identifiable on final fluoroscopic evaluation, one screw perforated the psoas groove and a second perforated the acetabular dome. Overall, 90 % of our screws were accurately and safely placed, upon the first attempt, within the anterior pelvic ring using the described gun barrel view. Conclusion Employing either open reduction, or following a closed or percutaneous reduction, the anterior pelvic ring gun barrel view can reproducibly guide safe placement of anterior pelvic ring screw fixation

Preserving the Knee in the Setting of High Segmental Tibial Bone and Massive Soft-Tissue Loss Using Vascularized Distal Tibial Bone Docking and a Foot Fillet Flap: A Case Report

Case: We discuss our reconstructive approach to avoid an above-knee amputation in a 33-year-old man presenting after lower extremity crush injury. We used a vascularized tibial bone flap and a foot fillet flap to restore length and joint functionality to the residual limb. The patient ambulates with good prosthetic fit on durable heel pad skin and 100° active knee motion. Conclusion: This pairing of intramedullary nail with vascularized bone flap and fillet flap to address soft-tissue coverage and retain limb length is a useful tool in traumatic lower extremity injury management, providing an alternative technique for tibial bone graft stabilization with robust, sensate tissue coverage

Preserving the Knee in the Setting of High Segmental Tibial Bone and Massive Soft-Tissue Loss Using Vascularized Distal Tibial Bone Docking and a Foot Fillet Flap: A Case Report

Case: We discuss our reconstructive approach to avoid an above-knee amputation in a 33-year-old man presenting after lower extremity crush injury. We used a vascularized tibial bone flap and a foot fillet flap to restore length and joint functionality to the residual limb. The patient ambulates with good prosthetic fit on durable heel pad skin and 100° active knee motion. Conclusion: This pairing of intramedullary nail with vascularized bone flap and fillet flap to address soft-tissue coverage and retain limb length is a useful tool in traumatic lower extremity injury management, providing an alternative technique for tibial bone graft stabilization with robust, sensate tissue coverage