Improving colonoscopy quality in the national VA healthcare system.

Background: Colorectal cancer (CRC) prevention is a Veterans Affairs (VA) priority. Colonoscopy quality, especially adenoma detection rate (ADR), is critical for effective screening. Our research indicates considerable variation in ADR among VA providers.

Treatment of Recalcitrant Femoral Shaft Nonunion With Medial Femoral Condyle Pedicled Autograft: Technical Trick.

Nonunited fractures of the femoral shaft and distal femur are usually successfully addressed with stabilization with or without autogenous bone grafting. For the small subset of these problems that prove recalcitrant to front-line treatment, a pedicled medial femoral condyle (MFC) bone flap can provide a source of vascularized autograft with minimal donor site morbidity. The MFC has gained recent widespread adoption as a free vascularized bone transfer, and here, we present a surgical technique and retrospective analysis of patients treated with a pedicled MFC technique.

Long-Term Impact of Vascular Surgery Stress on Frail Older Patients.

Background: Frailty is a syndrome where the ability to cope with acute physiological stress is compromised, although it is unclear what impact this stress has on long-term outcomes. Vascular-Physiological and Operative Severity Score for enumeration of Mortality and Morbidity is a validated method for calculating levels of stress associated with vascular procedures. We designed this study to evaluate the long-term impact of different levels of surgical stress among frail older patients undergoing vascular surgery procedures.

Ten-Year Survivorship, Patient-Reported Outcomes, and Satisfaction of a Fixed-Bearing Unicompartmental Knee Arthroplasty.

Background: We sought to determine the 10-year survivorship and reasons for revision for a fixed-bearing unicompartmental knee arthroplasty (UKA) design. In addition, we report on patient-reported outcomes and satisfaction and compare results of medial vs lateral compartment UKA and cemented vs cementless UKA with the same design.

Methods: We performed a retrospective cohort study on a single-surgeon case series using a single fixed-bearing UKA design in 158 consecutive patients who underwent 177 UKA procedures between July 2000 and December 2010.

Is the Fibular Station on Lateral Ankle Radiographs Symmetric? A Retrospective Observational Radiographic Study.

Background: Precise reduction of a syndesmosis after disruption is critical to improve patient physical function. Intraoperative lateral radiographs of the unaffected ankle are often used in clinical practice as a template for anatomic syndesmotic reduction because sagittal plane malreduction is common. However, there is little data to suggest fibular station, or the position of the fibula in the AP plane on the lateral radiograph, is symmetric side-to-side in patients.

Traction Time, Force and Postoperative Nerve Block Significantly Influence the Development and Duration of Neuropathy Following Hip Arthroscopy.

Purpose: To (1) evaluate the individual and combined effects of traction time and traction force on postoperative neuropathy following hip arthroscopy, (2) determine if perioperative fascia iliaca block has an effect on the risk of this neuropathy, and (3) identify if the these items had a significant association with the presence, location, and/or duration of postoperative numbness.

Methods: Between February 2015 and December 2016, a consecutive cohort of hip arthroscopy patients was prospectively enrolled. Traction time, force, and postoperative nerve block administration were recorded.

Is load application necessary when using computed tomography scans to diagnose syndesmotic injuries? A cadaver study.

Background: Injuries to the distal tibio-fibular ligaments are common. While pronounced injuries can be reliably diagnosed using conventional radiographs, assessment of subtle syndesmotic injuries is challenging. This cadaver study determines the impact of loading on the assessment of incomplete and more complete syndesmotic injuries when using weightbearing computed tomography (CT) scans.

Impact of Torque on Assessment of Syndesmotic Injuries Using Weightbearing Computed Tomography Scans.

Background: The diagnosis of subtle injuries to the distal tibiofibular syndesmosis remains elusive. Conventional radiographs miss a large subset of injuries that present without frank diastasis. This study evaluated the impact of torque application on the assessment of syndesmotic injuries when using weightbearing computed tomography (CT) scans.

Torque application helps to diagnose incomplete syndesmotic injuries using weight-bearing computed tomography images.

Objective: Accurate identification of distal tibio-fibular syndesmotic injuries is essential to limit potential deleterious post-traumatic effects. To date, conventional radiographs, computed tomography (CT), and magnetic resonance imaging (MRI) have shown limited utilization. This cadaver study evaluates the utility of weight-bearing CT scans on the assessment of incomplete and more complete syndesmotic injuries.

Nanostructure-Driven Replication of Soft Tissue Biomechanics in a Thermoplastic Elastomer Hydrogel.

Synthesis of hydrogel networks capable of accurately replicating the biomechanical demands of musculoskeletal soft tissues continues to present a formidable materials science challenge. Current systems are hampered by combinations of limited moduli at biomechanically relevant strains, inefficiencies driven by undesirable hysteresis and permanent fatigue, and recovery dynamics too slow to accommodate rapid cycling prominent in most biomechanical loading profiles. Here, we report on a novel paradigm in hydrogel design based on prefabrication of an efficient nanoscale network architecture using the melt-state self-assembly of amphiphilic block copolymers.

A Hydrogel Meniscal Replacement: Knee Joint Pressure and Distribution in an Ovine Model Compared to Native Tissue.

Pressure distribution of the native ovine knee meniscus was compared to a medial meniscectomy and three treatment conditions including a suture reattachment of the native tissue, an allograft, and a novel thermoplastic elastomer hydrogel (TPE) construct. The objective of this study was to assess the efficacy of a novel TPE hydrogel construct at restoring joint pressure and distribution. Limbs were loaded in uniaxial compression at 45°, 60°, and 75° flexion and from 0 to 181 kg.

Mechanical viability of a thermoplastic elastomer hydrogel as a soft tissue replacement material.

Hydrogels are a class of synthetic biomaterials composed of a polymer network that swells with water and as such they have both an elastic and viscous component making them ideal for soft tissue applications. This study characterizes the compressive, tensile, and shear properties of a thermoplastic elastomer (TPE) hydrogel and compares the results to published literature values for soft tissues such as articular cartilage, the knee meniscus, and intervertebral disc components. The results show the TPE hydrogel material is viscoelastic, strain rate dependent, has similar surface and bulk properties, displays minimal damping under dynamic load, and has tension-compression asymmetry.

Conversion of painful tibiotalocalcaneal arthrodesis to total ankle replacement using a 3-component mobile bearing prosthesis.

Background: The aim of this study was to assess the short-term clinical and radiographic outcomes in patients who underwent conversion of a painful tibiotalocalcaneal arthrodesis to a total ankle replacement.

Methods: Six patients with painful ankle arthrodesis after tibiotalocalcaneal arthrodesis were included in this study. In all patients, conversion to total ankle replacement was performed using a 3-generation, non-constrained, cementless three-component prosthesis.

Weightbearing Computed Tomography of the Foot and Ankle: Emerging Technology Topical Review.

Unlabelled: In the last decade, cone-beam computed tomography technology with improved designs allowing flexible gantry movements has allowed both supine and standing weight-bearing imaging of the lower extremity. There is an increasing amount of literature describing the use of weightbearing computed tomography in patients with foot and ankle disorders. To date, there is no review article summarizing this imaging modality in the foot and ankle.

Brush Polymer of Donor-Accepter Dyads via Adduct Formation between Lewis Base Polymer Donor and All Carbon Lewis Acid Acceptor.

A synthetic method that taps into the facile Lewis base (LB)→Lewis acid (LA) adduct forming reaction between the semiconducting polymeric LB and all carbon LA C for the construction of covalently linked donor-acceptor dyads and brush polymer of dyads is reported. The polymeric LB is built on poly(3-hexylthiophene) (P3HT) macromers containing either an alkyl or vinyl imidazolium end group that can be readily converted into the -heterocyclic carbene (NHC) LB site, while the brush polymer architecture is conveniently constructed via radical polymerization of the macromer P3HT with the vinyl imidazolium chain end. Simply mixing of such donor polymeric LB with C rapidly creates linked P3HT-C dyads and brush polymer of dyads in which C is covalently linked to the NHC junction connecting the vinyl polymer main chain and the brush P3HT side chains.

Dynamic compression of human and ovine meniscal tissue compared with a potential thermoplastic elastomer hydrogel replacement.

Understanding how human meniscal tissue responds to loading regimes mimetic of daily life as well as how it compares to larger animal models is critical in the development of a functionally accurate synthetic surrogate. Seven human and eight ovine cadaveric meniscal specimens were regionally sectioned into cylinders 5 mm in diameter and 3 mm thick along with 10 polystyrene-b-polyethylene oxide block copolymer-based thermoplastic elastomer (TPE) hydrogels. Samples were compressed to 12% strain at 1 Hz for 5000 cycles, unloaded for 24 h, and then retested.

Can a Three-Component Prosthesis be Used for Conversion of Painful Ankle Arthrodesis to Total Ankle Replacement?

Background: In patients with painful ankle arthrodesis, the surgical treatment is challenging, and may include takedown of ankle arthrodesis and conversion to a total ankle replacement (TAR). This procedure is technically demanding given the altered anatomy after arthrodesis. Few studies have evaluated TAR in the setting of prior arthrodesis.

Stereoregular Brush Polymers and Graft Copolymers by Chiral Zirconocene-Mediated Coordination Polymerization of P3HT Macromers.

Two poly(3-hexylthiophene) (P3HT) macromers containing a donor polymer with a polymerizable methacrylate (MA) end group, P3HT-CH₂-MA and P3HT-(CH₂)₂-MA, have been synthesized, and P3HT-(CH₂)₂-MA has been successfully homopolymerized and copolymerized with methyl methacrylate (MMA) into stereoregular brush polymers and graft copolymers, respectively, using chiral -zirconocene catalysts. Macromer P3HT-CH₂-MA is too sterically hindered to polymerize by the current Zr catalysts, but macromer P3HT-(CH₂)₂-MA is readily polymerizable via either homopolymerization or copolymerization with MMA in a stereospecific fashion with both ₂-ligated zirconocenium catalyst and -ligated zirconocenium catalyst . Thus, highly isotactic (with % ≥ 92%) and syndiotactic (with % ≥ 93%) brush polymers, -PMA--P3HT and -PMA--P3HT, as well as well-defined stereoregular graft copolymers with different grafted P3HT densities, -P(M)MA--P3HT and -P(M)MA--P3HT, have been synthesized using this controlled coordination-addition polymerization system under ambient conditions.

Association of a Frailty Screening Initiative With Postoperative Survival at 30, 180, and 365 Days.

Importance: As the US population ages, the number of operations performed on elderly patients will likely increase. Frailty predicts postoperative mortality and morbidity more than age alone, thus presenting opportunities to identify the highest-risk surgical patients and improve their outcomes.

Objective: To examine the effect of the Frailty Screening Initiative (FSI) on mortality and complications by comparing the surgical outcomes of a cohort of surgical patients treated before and after implementation of the FSI.

Development and Initial Validation of the Risk Analysis Index for Measuring Frailty in Surgical Populations.

Importance: Growing consensus suggests that frailty-associated risks should inform shared surgical decision making. However, it is not clear how best to screen for frailty in preoperative surgical populations.

Objective: To develop and validate the Risk Analysis Index (RAI), a 14-item instrument used to measure surgical frailty.

Tailoring mechanical response through coronal layer overlap in tethered micelle hydrogel networks.

Tethered micelle hydrogel networks based on the solution assembly of amphiphilic ABA-type block copolymers are prevalent throughout the hydrogel literature. However, the mechanical response of such systems is often determined largely by the integrity of the micellar core produced during solution assembly, not by the elements of the network structure upon which it is based. Using a solvent-free fabrication method based on the melt-state self-assembly of sphere-forming polystyrene-b-poly(ethylene oxide) (SO) diblock and SOS triblock copolymers blends, we have been able to produce tethered micelle hydrogel networks with fully vitrified cores that enable the elements of the network structure to determine the mechanical response.

Effects of degeneration on the compressive and tensile properties of human meniscus.

Healthy menisci function within the joint to prevent the underlying articular cartilage from excessive loads. Understanding how mechanical properties of menisci change with degeneration can drive future therapeutic studies to prevent this degeneration. Thus, the goal of this study was to characterize both compressive and tensile moduli of human menisci with varying degrees of gross damage due to osteoarthritis (OA).