Increased 90-Day Morbidity and Mortality Among Patients With Hip Fracture During the COVID-19 Pandemic.

Background: When coronavirus disease 2019 (COVID-19) first spread to the United States, our institution was at the outbreak's epicenter. Despite limited understanding of COVID-19's long-term effects, we continued performing surgical fixation of geriatric hip fractures under strict guidelines. This study examined the outcomes of these patients during the pandemic compared with those of patients treated pre-pandemic.

Overwrapping Bivalved Casts: Does the Material Matter?

Background: Circumferential integrity of bivalved casts (cut twice longitudinally) can be restored by overwrapping with different materials. This study compared the mechanical properties of solid casts and bivalved casts overwrapped with semirigid fiberglass (SF), elastic bandages (EB), and rigid fiberglass (RF) using an overwrapped-bivalved cast-bone fracture (OBCBF) model.

Methods: This study used an MTS Bionix Servohydraulic system to test properties of OBCBF models in 4 conditions: intact Control made of RF (not bivalved or overwrapped), a Rigid overwrapped model made of a Control bivalved and overwrapped with RF, a Semirigid overwrapped model made of a Control bivalved and overwrapped with SF, and an Elastic model made of a Control bivalved and overwrapped with EB.

Severity Of Radiographic Osteoarthritis: Association with Improved Patient Reported Outcomes Following Knee Arthroplasty.

Introduction: The Kellgren and Lawrence (KL) classification for knee osteoarthritis estimates disease severity. Its utility in predicting patient-reported outcomes (PROs) after primary total knee arthroplasty (pTKA) has been suggested. We hypothesized that patients who had higher preoperative KL grades would demonstrate greater improvements in PROs after pTKA.

Non-inferiority and Safety of Increased Povidone-Iodine (Betadine) Concentration for Irrigation Following Primary Total Joint Arthroplasty (TJA).

Introduction Diluted Betadine (Purdue Pharma, Stamford, Conn) irrigation following primary total joint arthroplasty (pTJA) may reduce the risk of periprosthetic joint infection (PJI). A recent study found a minimal inhibitory concentration (MIC) of 0.63% Povidone-iodine (Betadine) for several bacterial isolates.

Increased 90-Day Mortality and Morbidity Among Patients Recovering From Elective Primary Arthroplasty During the COVID-19 Pandemic in New York City.

All elective procedures were stopped in March 2020 because of the coronavirus disease 2019 (COVID-19) pandemic. We report the 90-day mortality and complications of patients who underwent primary arthroplasty before the stopping of elective procedures at a single academic medical center. A retrospective cohort study was conducted including patients who underwent elective primary arthroplasty between December 2019 and mid-March 2020.

Social Media Use and Its Impact on Physician Review Website Ratings in Hip and Knee Arthroplasty.

Background: The growth in social media (SM) use and consumer-driven health care has led more patients to rate surgeons on physician review websites (PRWs). This study assessed surgeon's professional SM presence and its relationship to PRW ratings.

Methods: This was a cross-sectional study of the American Association of Hip and Knee Surgeons members as of June 15, 2021.

Skin Reactions Following Primary Total Knee Arthroplasty With an Adhesive Superficial Closure System: A Case Series.

Background: We investigated a skin adhesive closure device consisting of a self-adhesive polyester mesh placed over the surgical incision, followed by a liquid adhesive that is spread over the mesh and surrounding the skin. It is intended to reduce wound closure times, scarring, and skin complications associated with traditional closure with sutures or staples. The aim of this study was to report on skin reactions in patients who underwent primary total knee arthroplasty (TKA) using the skin adhesive closure system.

Validation of Two Novel and Complementary Training Platforms for Small Joint Arthroscopy.

Purpose: We developed 2 complementary low-fidelity models to be used to create the tool skills needed to perform small joint arthroscopy. The purpose of the study was to establish the face and construct validity of the 2 models.

Methods: The "foundation model" was constructed from lemon and radish sections, and the "advanced model" was constructed from a chicken knee.

Black and Hispanic Patients Do Not Stay Longer After Primary Total Knee Arthroplasty: Results From an Urban Center Serving a Predominantly Minority Cohort.

Introduction: Previous reports identified minority race/ethnicity to be an independent risk factor for prolonged length of stay (LOS); however, these cohorts consisted of predominantly White patients. This study sought to evaluate minority status as an independent risk factor for prolonged LOS after primary total knee arthroplasty (TKA) in a predominantly Hispanic and Black cohort.

Methods: This was a retrospective study using an institutional database of patients who underwent primary TKA between the years 2016 and 2019.

Estrogen depletion on In vivo osteocyte calcium signaling responses to mechanical loading.

Microstructural adaptation of bone in response to mechanical stimuli is diminished with estrogen deprivation. Here we tested in vivo whether ovariectomy (OVX) alters the acute response of osteocytes, the principal mechanosensory cells of bone, to mechanical loading in mice. We also used super resolution microscopy (Structured Illumination microscopy or SIM) in conjunction with immunohistochemistry to assess changes in the number and organization of "osteocyte mechanosomes" - complexes of Panx1 channels, P2X7 receptors and CaV3 voltage-gated Ca channels clustered around αβ integrin foci on osteocyte processes.

Role of pannexin 1 channels in load-induced skeletal response.

The pannexin 1 (Panx1) channel is a mechanosensitive channel that interacts with P2X7 receptors (P2X7R) to form a functional complex that has been shown in vitro to play an essential role in osteocyte mechanosignaling. While the participation of P2X7R in skeletal responses to mechanical loading has been demonstrated, the role of Panx1 and its interplay with P2X7R still remain to be determined. In this study, we use a global Panx1 mouse model and in vivo mechanical loading to demonstrate that Panx1 channels play an essential role in load-induced skeletal responses.

Osteocyte calcium signals encode strain magnitude and loading frequency in vivo.

Osteocytes are considered to be the major mechanosensory cells of bone, but how osteocytes in vivo process, perceive, and respond to mechanical loading remains poorly understood. Intracellular calcium (Ca) signaling resulting from mechanical stimulation has been widely studied in osteocytes in vitro and in bone explants, but has yet to be examined in vivo. This is achieved herein by using a three-point bending device which is capable of delivering well-defined mechanical loads to metatarsal bones of living mice while simultaneously monitoring the intracellular Ca responses of individual osteocytes by using a genetically encoded fluorescent Ca indicator.

Lactation-Induced Changes in the Volume of Osteocyte Lacunar-Canalicular Space Alter Mechanical Properties in Cortical Bone Tissue.

Osteocytes can remove and remodel small amounts of their surrounding bone matrix through osteocytic osteolysis, which results in increased volume occupied by lacunar and canalicular space (LCS). It is well established that cortical bone stiffness and strength are strongly and inversely correlated with vascular porosity, but whether changes in LCS volume caused by osteocytic osteolysis are large enough to affect bone mechanical properties is not known. In the current studies we tested the hypotheses that (1) lactation and postlactation recovery in mice alter the elastic modulus of bone tissue, and (2) such local changes in mechanical properties are related predominantly to alterations in lacunar and canalicular volume rather than bone matrix composition.

A new perspective on mechanisms governing skeletal complications in type 1 diabetes.

This review focuses on bone mechanobiology in type 1 diabetes (T1D), an area of research on diabetes-associated skeletal complications that is still in its infancy. We first provide a brief overview of the deleterious effects of diabetes on the skeleton and of the knowledge gained from studies with rodent models of T1D. Second, we discuss two specific hallmarks of T1D, low insulin and high glucose, and address the extent to which they affect skeletal health.

P2X7R-Panx1 Complex Impairs Bone Mechanosignaling under High Glucose Levels Associated with Type-1 Diabetes.

Type 1 diabetes (T1D) causes a range of skeletal problems, including reduced bone density and increased risk for bone fractures. However, mechanisms underlying skeletal complications in diabetes are still not well understood. We hypothesize that high glucose levels in T1D alters expression and function of purinergic receptors (P2Rs) and pannexin 1 (Panx1) channels, and thereby impairs ATP signaling that is essential for proper bone response to mechanical loading and maintenance of skeletal integrity.

Pannexin-1 and P2X7-Receptor Are Required for Apoptotic Osteocytes in Fatigued Bone to Trigger RANKL Production in Neighboring Bystander Osteocytes.

Osteocyte apoptosis is required to induce intracortical bone remodeling after microdamage in animal models, but how apoptotic osteocytes signal neighboring "bystander" cells to initiate the remodeling process is unknown. Apoptosis has been shown to open pannexin-1 (Panx1) channels to release adenosine diphosphate (ATP) as a "find-me" signal for phagocytic cells. To address whether apoptotic osteocytes use this signaling mechanism, we adapted the rat ulnar fatigue-loading model to reproducibly introduce microdamage into mouse cortical bone and measured subsequent changes in osteocyte apoptosis, receptor activator of NF-κB ligand (RANKL) expression and osteoclastic bone resorption in wild-type (WT; C57Bl/6) mice and in mice genetically deficient in Panx1 (Panx1KO).

Bone microdamage, remodeling and bone fragility: how much damage is too much damage?

Microdamage resulting from fatigue or 'wear and tear' loading contributes to bone fragility; however, the full extent of its influence is not completely understood. Linear microcracks (∼50-100 μm) and diffuse damage (clusters of sublamellar-sized cracks) are the two major bone microdamage types, each with different mechanical and biological consequences. Healthy bone, due to its numerous microstructural interfaces and its ability to affect matrix level repair, deals effectively with microdamage.

Structural and mechanical repair of diffuse damage in cortical bone in vivo.

Physiological wear and tear causes bone microdamage at several hierarchical levels, and these have different biological consequences. Bone remodeling is widely held to be the mechanism by which bone microdamage is repaired. However, recent studies showed that unlike typical linear microcracks, small crack damage, the clusters of submicron-sized matrix cracks also known as diffuse damage (Dif.

In muscle lengthening surgery multiple aponeurotomy does not improve intended acute effects and may counter-indicate: an assessment by finite element modelling.

The goal was to assess the effects of multiple aponeurotomy on mechanics of muscle with extramuscular myofascial connections. Using finite element modelling, effects of combinations of the intervention carried out at a proximal (P), an intermediate (I) and a distal (D) location were studied: (1) Case P, (2) Case P-I, (3) Case P-D and (4) Case P-I-D. Compared to Case P, the effects of multiple interventions on muscle geometry and sarcomere lengths were sizable for the distal population of muscle fibres: e.