Using preoperative planning software to assess the effect of head length on prosthetic range of motion in a high-risk population: a three-dimensional modeling study.

PURPOSE: Concurrent use of minus heads with tapered stems in total hip arthroplasty (THA) decreases the prosthetic range of motion (pROM). Three-dimensional preoperative templating can simulate the location of the impingement by taking the hip through a virtual pROM. This enables surgeons to simulate how modifying the type of implant, orientation, and position influences impingement. We hypothesized that CT-based modeling would result in a decrease in the pROM, thereby increasing the risk of impingement when minus heads are used. METHODS: Forty-three patients who underwent robotic-assisted primary THAs were included. Prosthetic head diameter (32/36-mm) and head length (minus/zero/plus) were the predictors. Maximum external rotation at full hip extension and internal rotation at 90° and 100° of flexion prior to prosthetic impingement were the outcome variables. A CT-based preoperative planning software was used for pROM estimation and impingement detection. RESULTS: Significant decreases in pROM were found for both head diameters as the head length decreased and was more pronounced in external rotation during full hip extension (changes of 2.8-3.4° for the 32-mm head and 1.6-2.8° for the 36-mm head (p = 0.00011)). The magnitude of loss in pROM when using a minus head was larger than the gain provided by a plus head in tapered stems (p < 0.0001). CONCLUSION: Head length affects the offset and pROM. When the use of minus heads or smaller heads is indicated, 3D preoperative templating for assessing postoperative pROM and impingement provides surgeons with options to consider alternate surgical plans offering additional assurance and protection from dislocation.

Off-the-Shelf Tibial Cone Sizes May Not Accommodate All Patients' Bone Morphology and May Lead to Cortical Breaches in Revision Total Knee Arthroplasty: A 3D Modeling Study.

Background: In revision total knee arthroplasty, tibial cones have demonstrated improved longevity and reduced incidence of aseptic loosening. Several currently available "off-the-shelf" (OTS) cone systems may not have sizes to accommodate all patient bone morphologies. Methods: Computed tomographies from one hundred primary total knee arthroplasty patients and dimensions of 4 OTS cones were obtained. Press-fit stems were positioned in 3D tibia models to fit the diaphyseal trajectory. Cones were positioned around the stem at 1, 6, and 13 mm resections measured from the trough of the medial tibial plateau, simulating proximal tibial cuts and bone loss. Tibias were examined for cortical breaching following modeled cone preparation. Results: Increased rate of breaching was observed as size and depth of the cone increased. In 2/49 (4.1%) male and 19/46 (41.3%) female tibias, cones could not be positioned without breaching. No breaches were found in 22/49 (45.0%) male and 5/46 (10.9%) female tibias. For every 1 centimeter increase in patient height, odds of breaching decreased by 12% (odds ratio: 0.88, confidence interval: 0.84, 0.92). For every size increase in cone width, odds of breaching increased by 34% (odds ratio: 1.34, confidence interval: 1.28, 1.47). Placing cones deeper also increased breaching compared to the 1 mm cut. Conclusions: In revision total knee arthroplasty, smaller OTS or custom tibial cones may be needed to fit a patient's proximal tibial geometry. This is especially true in patients not accommodated by the OTS cone sizes we tested, which impacted shorter patients and/or those with substantial bone loss requiring more tibial resection and deeper cone placement. Use of smaller or custom tibial cones should be considered where indicated.

Quality improvement exercises in Inflammatory Bowel Disease (IBD) services: A scoping review.

OBJECTIVE: Quality Improvement initiatives aim to improve care in Inflammatory Bowel Disease (IBD). These address a range of aspects of care including adherence to published guidelines. The objectives of this review were to document the scope and quality of published quality improvement initiatives in IBD, highlight successful interventions and the outcomes achieved. DESIGN/METHOD: We searched MEDLINE, EMBASE, CINAHL and Web of Science. Two reviewers independently screened and extracted data. We included peer reviewed articles or conference proceedings reporting initiatives intended to improve the quality of IBD care, with both baseline and prospectively collected follow-up data. Initiatives were categorised based on problems, interventions and outcomes. We used the Quality Improvement Minimum Quality Criteria Set instrument to appraise articles. We mapped the focus of the articles to the six domains of the IBD standards. RESULTS: 100 studies were identified (35 full text; 65 conference abstracts). Many focused on vaccination, medication, screening, or meeting multiple quality measures. Common interventions included provider education, the development of new service protocols, or enhancements to the electronic medical records. Studies principally focused on areas covered by the IBD standards 'ongoing care' and 'the IBD service', with less focus on standards 'pre-diagnosis', 'newly diagnosed', 'flare management', 'surgery' or 'inpatient care'. CONCLUSION: Good quality evidence exists on approaches to improve the quality of a narrow range of IBD service functions, but there are many topic areas with little or no published quality improvement initiatives. We highlight successful quality improvement interventions and offer recommendations to improve reporting of future studies.

Platelet rich plasma therapy versus other modalities for treatment of plantar fasciitis: A systematic review and meta-analysis.

INTRODUCTION: Plantar fasciitis (PF) is the most common cause of heel pain in adults. There are numerous non-operative treatments available including platelet rich plasma (PRP) injections. PPR has demonstrated effectiveness for a range of musculoskeletal conditions including plantar fasciitis. PURPOSE/OBJECTIVE: To compare the effectiveness of PRP to other conservative treatment options for the management of PF. METHODS: A systematic search of PubMed and Google Scholar was performed for randomized control trials (RCT) comparing PRP to other treatment modalities. Studies met inclusion criteria if mean and standard deviations for visual analog scale (VAS) pain scores, plantar fascia thickness (PFT), Foot Function Index (FFI), or American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Score were reported. Mean differences (MD) were used to compare VAS pain, PFT, FFI, and AOFAS between PRP and other treatments. RESULTS: Twenty-one RCTs which altogether included 1356 patients were included in the meta-analysis. PRP demonstrated significantly greater improvements in VAS pain scores compared to extracorporeal shock wave therapy (ESWT) (SMD: 0.86; CI: [0.30, 1.41]; p = 0.002), corticosteroid injections (CSI) (SMD: 1.08; CI: [0.05, 2.11]; p = 0.04), and placebo (SMD: 3.42; CI: [2.53, 4.31]; p < 0.00001). In terms of FFI, no significant differences existed among PRP, ESWT, CSI, dextrose prolotherapy (DPT), and meridian trigger points (MTP) in enhancing foot functionality. However, PRP demonstrated a marked advantage over phonophoresis, showing a substantial improvement in FFI scores (SMD: 3.07, 95% CI: 2.34-3.81). PRP did not demonstrate superiority over ESWT, CSI, or MTP for improving PFT, but it was notably more effective than phonophoresis (SMD: 3.18, 95% CI: 2.43-3.94). PRP demonstrated significantly greater improvements in AOFAS scores over CSI (SMD: 3.31, CI: [1.35, 5.27], p = 0.0009) and placebo (SMD: 3.75; CI: [2.81, 4.70]; p < 0.00001). CONCLUSION: PRP is more effective than CSI, ESWT, and placebo in reducing VAS and more effective than CSI and placebo in improving AOFAS. PRP did not demonstrate a consistent advantage across all outcome measures, such as PFT and FFI. These findings underscore the complexity of PF treatment and call for a more standardized approach to PRP preparation and outcome measurement. LEVEL OF EVIDENCE: Level I Meta-Analysis.

Some Offset Restoration Options Can Paradoxically Lead to Decreased Range of Motion in Primary Total Hip Arthroplasty: A 3-Dimensional Computer Simulation Study.

BACKGROUND: In total hip arthroplasty (THA), femoral offset restoration results in optimal biomechanics and range of motion (ROM) without bone-bone impingement. We hypothesized that differences in implant design features significantly affect bone-bone impingement risk in primary THA. METHODS: This retrospective computer simulation study included a cohort of 43 primary robotic arm-assisted THA. Considering sagittal pelvic tilt, we measured the maximum external rotation at 0° hip flexion and the maximum internal rotation at both 90° and 100° hip flexion before any bone-bone impingement occurred. To influence the offset, we included neutral or extended polyethylene liners, neutral or plus prosthetic heads, standard or high-offset stems, and stems with 132° or 127° neck angles. RESULTS: Extended polyethylene liner use resulted in decreased bone-bone impingement for both stems but also decreased prosthetic ROM in hip extension (mean -4.5 to 5°, range -10 to 0°) and hip flexion (mean -3 to 3.7°, range -10 to 0°) due to decreases in head diameter. Using a plus head or different stem offset/neck angle options resulted in either (1) no improvement in ROM (stem 1: 60%; stem 2: 28%) or (2) a paradoxical increase in bone-bone impingement (stem 1 with 127°: 19% and stem 2 with high offset option: 7%). CONCLUSION: Counterintuitively, a subset of patients experience a paradoxical increase in bone-bone impingement when transitioning from standard to high-offset or varus necks due to the pelvic and proximal femoral bone shape. For this group of patients, preoperative personalized 3-dimensional modeling may help guide implant choice for optimizing outcomes.

Orthopaedic Nurse Navigators and Total Joint Arthroplasty Preoperative Optimization: Improving Patient Access to Musculoskeletal Care.

Preoperative optimization programs for total joint arthroplasty identify and address risk factors to reduce postoperative complications, thereby improving patients' ability to be safe surgical candidates. This article introduces preoperative optimization programs and describes the role of orthopaedic nurse navigators. This foundation will be used to produce an article series with recommendations for optimization of several modifiable biopsychosocial factors. We consulted orthopaedic nurse navigators across the United States and conducted a literature review regarding preoperative optimization to establish the importance of nurse navigation in preoperative optimization. The responsibilities of nurse navigators, cited resources, and structure of preoperative optimization programs varied among institutions. Optimization programs relying on nurse navigators frequently demonstrated improved outcomes. Our discussions and literature review demonstrated the integral role of nurse navigators in preoperative optimization. We will discuss specific risk factors and how nurse navigators can manage them throughout this article series.

Hip Abduction Can Be Considered the Sole Posterior Precaution Strategy to Lower the Rate of Impingement After Posterior Approach Total Hip Arthroplasty With Large Femoral Head: A Computer Simulation Study.

BACKGROUND: Studies suggest that posterior hip precautions are unnecessary after total hip arthroplasty; however, many surgeons and patients choose to follow these precautions to some extent. In this study, we hypothesized that 20° of hip abduction would be sufficient to prevent impingement and dislocation in motions requiring hip flexion when using larger prosthetic heads (≥36 mm) when the acetabular implant is placed within a reasonable orientation (anteversion:15-25° and inclination: 40-60°). METHODS: Using a robotic hip platform, we investigated the effect of hip abduction on prosthetic and bony impingement in 43 patients. For the flexed seated position, anterior pelvic tilt angles of 10 and 20° were chosen, while anterior pelvic tilt angles of 70 and 90° were chosen for the bending forward position. An additional 10° of hip external rotation and 10 or 20° of hip internal rotation were also added to the simulation. One hip received a 32-mm head; otherwise, 36-, 40-mm, or dual-mobility heads were used. The study power was 0.99, and the effect size was 0.644. RESULTS: In 65% of the cases, bone-bone impingement between the calcar and anterior-inferior iliac spine was the main type of impingement. The absolute risk of impingement decreased between 0 and 16.3% in both tested positions with the addition of 20° hip abduction. CONCLUSION: With modern primary total hip arthroplasty stems (low neck diameter) and an overall acceptable cup anteversion angle, small degrees of hip abduction may be the only posterior hip precaution strategy required to lower the risk of dislocation among patients. Future studies can potentially investigate the concept of personalized hip precautions based on preoperative computer simulations, utilized implants, hip-spine relations, and final implant orientation.

Interventions for the prevention or treatment of epidural-related maternal fever: a systematic review and meta-analysis.

BACKGROUND: Epidural-related maternal fever in women in labour has consequences for the mother and neonate. There has been no systematic review of preventive strategies. METHODS: RCTs evaluating methods of preventing or treating epidural-related maternal fever in women in active labour were eligible. We searched MEDLINE, EMBASE, CINAHL, Web of Science, CENTRAL, and grey literature sources were searched from inception to April 2021. Two review authors independently undertook study selection. Data extraction and quality assessment was performed by a single author and checked by a second. The Cochrane Risk of Bias 2 tool was used. Meta-analyses for the primary outcome, incidence of intrapartum fever, were performed using the DerSimonian and Laird random effects model to produce summary risk ratios (RRs) with 95% confidence intervals (95% CIs). RESULTS: Forty-two records, representing 34 studies, were included. Methods of reduced dose epidural reduced the incidence of intrapartum fever, but this was not statistically significant when six trials at high risk of bias were removed (seven trials; 857 participants; RR=0.83; 95% CI, 0.41-1.67). Alternative methods of analgesia and high-dose prophylactic systemic steroids reduced the risk of intrapartum fever compared with epidural analgesia. Prophylactic paracetamol was not effective. CONCLUSIONS: There is no clear evidence to support the use of any individual preventative or therapeutic intervention for epidural-related maternal fever. Further research should focus on understanding the mechanism of fever development to enable RCTs of potential interventions to reduce the incidence of intrapartum fever development and the subsequent disease burden felt by the neonate. CLINICAL TRIAL REGISTRATION: CRD42021246929.

Temperature-Dependent Suppression of Polymer Diffusion in Polymer Nanocomposites.

The polymer center-of-mass tracer diffusion coefficient in athermal polymer nanocomposites (PNCs) composed of polystyrene and phenyl-capped, spherical silica nanoparticles was measured over a range of temperatures and nanoparticle concentrations using elastic recoil detection. The polymer tracer diffusion coefficient in the PNC relative to the bulk decreases with increasing nanoparticle concentration and is unexpectedly more strongly reduced at higher temperatures. This unusual temperature dependence of polymer diffusion in PNCs cannot be explained by the reptation model or a modified version incorporating an effective tube diameter. Instead we show that our results are consistent with a mechanism based on nanoparticle-imposed configurational entropy barriers.

Anisotropic Polymer Conformations in Aligned SWCNT/PS Nanocomposites.

Polymer radii of gyration in isotropic single-walled carbon nanotube (SWCNT)/polymer nanocomposites were previously found to increase with increasing SWCNT concentration. Here, the SWCNTs in nanocomposites were aligned by melt fiber spinning, and the polymer chain conformations were found to be anisotropic. Using SAXS and SANS, the anisotropic SWCNT meshes were found to have smaller mesh sizes in the direction perpendicular to the alignment direction than along the alignment direction. At fixed SWCNT orientation, the radius of gyration was probed parallel and perpendicular to the alignment direction, Rgpar and Rgper, respectively, using SANS. With increasing SWCNT concentration, Rgper increases significantly more than Rgpar, such that the extent of anisotropy increases with SWCNT concentration. The anisotropic polymer conformation is larger in the direction perpendicular to the alignment direction, which corresponds to a smaller SWCNT mesh size. Thus, when the SWCNT concentration and alignment combine to produce a SWCNT mesh size that is smaller than the unperturbed Rg, the polymer conformation circumvents the SWCNTs by adopting a larger Rg. Changes in the polymer conformation in nanocomposites with rod-like nanoparticles has important ramifications for entanglement density, polymer dynamics, and mechanical properties.

A size-dependent nanoscale metal-insulator transition in random materials.

Insulators and conductors with periodic structures can be readily distinguished, because they have different band structures, but the differences between insulators and conductors with random structures are more subtle. In 1958, Anderson provided a straightforward criterion for distinguishing between random insulators and conductors, based on the 'diffusion' distance ζ for electrons at 0 K (ref. 3). Insulators have a finite ζ, but conductors have an infinite ζ. Aided by a scaling argument, this concept can explain many phenomena in disordered electronic systems, such as the fact that the electrical resistivity of 'dirty' metals always increases as the temperature approaches 0 K (refs 4-6). Further verification for this model has come from experiments that measure how the properties of macroscopic samples vary with changes in temperature, pressure, impurity concentration and applied magnetic field, but, surprisingly, there have been no attempts to engineer a metal-insulator transition by making the sample size less than or more than ζ. Here, we report such an engineered transition using six different thin-film systems: two are glasses that contain dispersed platinum atoms, and four are single crystals of perovskite that contain minor conducting components. With a sample size comparable to ζ, transitions can be triggered by using an electric field or ultraviolet radiation to tune ζ through the injection and extraction of electrons. It would seem possible to take advantage of this nanometallicity in applications.