Are current rates of uncemented fixation in total hip arthroplasty supported by the literature? An update on the uncemented paradox.

The optimal fixation method in total hip arthroplasty (THA) remains controversial. Initial concerns related to the long-term performance of cement fixation as well as cement disease led to the development of cementless implants, and registry data has indicated that the use of this type of fixation has increased in recent years. However, data from these same registries has not shown any improvement in outcomes when compared to cement fixation. On the contrary, while similar outcomes are seen when comparing these fixation types in younger patients (<70 years of age), cementless fixation has shown increased implant failure and revision rates in elderly patients (>70 years of age). Given the increased projected volume of THA in the United States over the next decade, it is important to utilise available data to make clinical decisions that minimise not only individual patient harm, but also the burden on the healthcare system itself. This review provides an overview of currently available outcomes data comparing cement and cementless fixation, as well as an updated analysis of current trends in fixation use in THA. We furthermore provide a comprehensive technique guide to help surgeons optimise cement fixation of the femoral component for THA and hemiarthroplasty.

"Stuck in the middle": the missing lumbosacral link in total hip arthroplasty.

INTRODUCTION: Spinopelvic mobility drives functional acetabular position, influencing dislocation risk after total hip arthroplasty (THA). Patients have been described as "stuck sitting" or "stuck standing" based on pelvic tilt (PT). We hypothesised that some patients are "stuck in the middle," meaning their PT changes minimally from sitting to standing - increasing their risk of dislocation. METHODS: We reviewed 195 patients with standing and sitting whole body radiographs prior to THA. Standing anterior pelvic plane tilt (APPT) and standing and sitting sacral slope (SS) were measured and used to calculate sitting APPT. Normal standing and sitting were defined as APPT >-10° and <-20°, respectively. Spinal stiffness was classified as <10° change in sacral slope between sitting and standing. Patients were categorised as: (A) able to fully sit and stand; (B) "stuck sitting" - able to fully sit; unable to fully stand; (C) "stuck standing" - able to fully stand; unable to fully sit; or (D) "stuck in the middle" - unable to sit or stand fully. RESULTS: 84 patients could sit and stand normally (A), 22 patients were stuck sitting (B), 76 patients were stuck standing (C), and 13 patients were stuck in the middle (D). While 111 patients (56.9%) were considered stuck, only 58 patients (29.7%) met criteria for spinal stiffness. DISCUSSION: We identified a subset of patients with stiff spines and abnormal PT in both sitting and standing, including 37.1% of patients who would be classified as "stuck sitting" based only on standing radiographs. Placing acetabular components in less than anatomic anteversion in these patients may increase posterior dislocation risk.

Local Trends in Total Joint Arthroplasty and Orthopaedic Surgeon Distribution in the United States.

INTRODUCTION: Total joint arthroplasty (TJA) volume and the number of orthopaedic surgeons in the United States have increased in recent years, but local growth variation has not been studied. This study assesses recent changes in state-level distribution of orthopaedic surgeons in the United States and corresponding local trends in TJA volume. METHODS: Data from the National Inpatient Sample database (2000 to 2014) were reviewed. Urban versus rural setting and teaching versus nonteaching hospitals were identified among TJA procedures for comparison. Data from the American Academy of Orthopaedic Surgeons (2002 to 2016) detailing orthopaedic surgeon practice location were evaluated, and linear regression analysis was used to correlate state population data with orthopaedic surgeon density. RESULTS: From 2000 to 2014, there was a 0.1% to 0.3% (P < 0.01) annual decrease in the proportion of TJA procedures conducted in rural hospitals. No notable change was observed in the proportion of TJA procedures conducted at urban teaching versus nonteaching hospitals. Linear regression analysis demonstrated that decreased state population was associated with higher orthopaedic surgeon density (adjusted R2 = 0.114, P < 0.01). States with a higher percentage of population living in rural areas had a lower density of orthopaedic surgeons in the South region and a higher density of orthopaedic surgeons in the remainder of the county. CONCLUSIONS: Less populated, rural states have a higher density of orthopaedic surgeons than states with increased population and less rural areas. Although TJA volume has increased since 2000, the proportion of TJA procedures conducted at rural hospitals has decreased. No change was found in the proportion of TJA procedures conducted at urban teaching versus nonteaching hospitals. This may indicate that more patients living in rural areas are seeking TJA care in urban centers. Future studies are needed to confirm this and ensure that patients living in rural areas have appropriate access to TJA care.

Patients with insulin-dependent diabetes are at greater risk for perioperative adverse outcomes following total hip arthroplasty.

BACKGROUND: The prevalence of diabetes mellitus (DM) continues to increase among patients undergoing total hip arthroplasty (THA). It is unclear how insulin use is correlated with risk for adverse outcomes. METHODS: A cohort of 146,526 patients undergoing primary THA were identified in the 2005-2017 National Surgical Quality Improvement Program database. Patients were classified as insulin-dependent diabetic (IDDM), non-insulin-dependent diabetic (NIDDM), or not diabetic. Multivariate analyses were used. RESULTS: Compared to patients without diabetes, patients with NIDDM were at increased risk for 4 of 17 perioperative adverse outcomes studied. Patients with IDDM were at increased risk for those 4 and 8 additional adverse outcomes (12 of the 17 studied). CONCLUSION: These findings have important implications for preoperative risk stratification and quality improvement initiatives.

Reduced postoperative morbidity in computer-navigated total knee arthroplasty: A retrospective comparison of 225,123 cases.

BACKGROUND: Total knee arthroplasty (TKA) is one of the most common elective surgical procedures in the United States, with more than 650,000 performed annually. Computer navigation technology has recently been introduced to assist surgeons with planning, performing, and assessing TKA bone cuts. The aim of this study is to assess postoperative complication rates after TKA performed using computer navigation assistance versus conventional methods. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for unilateral TKA cases from 2008 to 2016. The presence of the CPT modifier for use of computer navigation was used to separate cases of computer-navigated TKA from conventional TKA. Multivariate and propensity-matched logistic regression analyses were performed to control for demographics and comorbidities. RESULTS: There were 225,123 TKA cases included; 219,880 were conventional TKA (97.7%) and 5,243 were navigated (2.3%). Propensity matching identified 4,811 case pairs. Analysis demonstrated no significant differences in operative time, length of stay, reoperation, or readmission, and no differences in rates of post-op mortality at 30 days postoperatively. Compared to conventional cases, navigated cases were at lower risk of serious medical morbidity (18% lower, p = 0.009) within the first 30 days postoperatively. CONCLUSION: After controlling for multiple known risk factors, navigated TKA patients demonstrated lower risk for medical morbidity, predominantly driven by lower risk for blood transfusion. Given these findings, computer-navigation is a safe surgical technique in TKA.

In Kinematically Aligned Total Knee Arthroplasty, Failure to Recreate Native Tibial Alignment Is Associated With Early Revision.

BACKGROUND: The goal of kinematically aligned (KA) total knee arthroplasty (TKA) is to restore native knee anatomy. However, there are concerns about patellofemoral tracking problems with this technique that lead to early revision. We measured the differences between preoperative anatomic alignment and postoperative component alignment in a consecutive series of KA TKA and evaluated the association between alignment changes and the likelihood of early revision. METHODS: The charts of 219 patients who underwent 275 KA TKA procedures were reviewed. Preoperative anatomic alignment and postoperative tibial and femoral component alignment were measured radiographically. The difference in component alignment compared with preoperative anatomic alignment was compared between patients who underwent aseptic revision and those who did not at a minimum of 12 months of follow-up. Receiver operating characteristic curves were created for statistically significant variables, and the Youden index was used to determine optimal alignment thresholds with regard to likelihood of revision surgery. RESULTS: Change in tibial component alignment compared with native alignment was greater (P = .005) in the revision group (5.0° ± 3.7° of increased varus compared with preoperative anatomic tibial angle) than in the nonrevision group (1.3° ± 4.2° of increased varus). The Youden index indicated that increasing tibial varus by >2.2° or more is associated with increased likelihood of revision. Preoperative anatomic alignment and change in femoral alignment and overall joint alignment (ie, Q angle) were not associated with increased likelihood of revision. CONCLUSION: Small increases in tibial component varus compared with native alignment are associated with early aseptic revision in patients undergoing KA TKA.

Tunable synthetic control of soft polymeric nanoparticle morphology.

With a growing variety of nanoparticles available, research probing the influence of particle deformability, morphology, and topology on the behavior of all polymer nanocomposites is also increasing. In particular, the behavior of soft polymeric nanoparticles in polymer nanocomposites has displayed unique behavior, but their precise performance depends intimately on the internal structure and morphology of the nanoparticle. With the goal of providing guidelines to control the structure and morphology of soft polymeric nanoparticles, we have examined monomer starved semi-batch nano-emulsion polymerizations that form organic, soft nanoparticles, to correlate the precise structure of the nanoparticle to the rate of monomer addition and crosslinking density. The synthesis method produces 5-20 nm radii polystyrene nanoparticles with tunable morphologies. We report small angle neutron scattering (SANS) results that correlate synthetic conditions to the structural characteristics of soft polystyrene nanoparticles. These results show that the measured molecular weight of the nanoparticles is controlled by the monomer addition rate, the total nanoparticle radius is controlled by the excess surfactant concentration, and the crosslinking density has a direct effect on the topology of each nanoparticle. These studies thus provide pathways to control these 3 structural characteristics of the nanoparticle. This research, therefore provides a conduit to thoroughly investigate the effect of structural features of soft nanoparticles on their individual properties and those of their polymer nanocomposites.

Not just a talking shop: practitioner perspectives on how communities of practice work to improve outcomes for people experiencing multiple exclusion homelessness.

Within homelessness services recent policy developments have highlighted the need for integration and improved collaborative working and also, the need for "Psychologically Informed Environments" (PIES) in which workers are better equipped to manage the "complex trauma" associated with homelessness. Drawing on the findings of an evaluation of a multi-site development programme, this paper demonstrates how both these policy aspirations might be implemented through a single delivery vehicle (a community of practice). The paper describes how organizational, educational and psychosocial theory was used to inform programme design and reflects on the utility of these approaches in the light of the evaluation findings. It is reported that communities of practice can deliver significant performance gains in terms of building collaborative relationships and opening-up opportunities for interprofessional education and learning. Filling an important knowledge gap, it also suggested how (professional) participation in a community of practice might work to improve outcomes for service users. Most likely we see those outcomes as being linked to tackling exclusion by sustaining the workforce itself, that is in motivating workers to remain engaged and thinking positively in what is an emotionally challenging and stressful job role.

Perspectives on Erving Goffman's "Asylums" fifty years on.

Erving Goffman's "Asylums" is a key text in the development of contemporary, community-orientated mental health practice. It has survived as a trenchant critique of the asylum as total institution, and its publication in 1961 in book form marked a further stage in the discrediting of the asylum model of mental health care. In this paper, some responses from a range of disciplines to this text, 50 years on, are presented. A consultant psychiatrist with a special interest in cultural psychiatry and mental health legislation, two collaborating psychotherapists in adult and forensic mental health, a philosopher, and a recent medical graduate, present their varying responses to the text. The editors present these with the hope of encouraging further dialogue and debate from service users, carers, clinicians, and academics and researchers across a range of disciplines.

Interrater and intrarater reliability of photoplethysmography for measuring toe blood pressure and toe-brachial index in people with diabetes mellitus.

BACKGROUND: A reliable tool to measure arterial flow to the feet in people with diabetes is required given that they are particularly prone to peripheral arterial disease. Traditionally, the ankle brachial index (ABI) has been used to measure arterial circulation, but its application is limited due to calcification of larger arteries. More recently, toe pressure and the toe brachial index (TBI) has been suggested as superior to ABI measurements because they assess smaller digital arteries less prone to arterial calcification. However, reliability studies for the clinical use of photoplethysmography (PPG) in people with diabetes are lacking. METHODS: Sixty people with diabetes mellitus (35 males and 25 females, mean age 59.6 yrs) consented to take part in the study. The majority (92%) had type 2 diabetes and 8% had type 1 diabetes. Forty-three percent were diagnosed as having peripheral neuropathy when tested using a biothesiometer and 15% were current smokers (10 - 40/day). A podiatrist and a diabetes educator measured toe and brachial blood pressure independently and in a random order using PPG. These measurements were repeated again seven days later, and subsequently analysed with intraclass correlation coefficients (ICC), 95% confidence intervals (CI) and standard error of measurement (SEM). RESULTS: The intrarater reliability of measuring toe pressures was excellent (ICC3,1 =0.78-0.79, SEM 8 mmHg) and interrater reliability was also excellent (ICC2,2 = 0.93, SEM 4 mmHg). The intrarater reliability for measuring brachial pressures was generally poor (ICC3,1 = 0.40 - 0.42, SEM 19 mmHg) and interrater reliability was fair-good (ICC2,2. 0.65, SEM 14 mmHg). The TBI intrarater reliability was fair-good (ICC3,1 = 0.51-0.72, SEM 0.08), whilst the interrater reliability of TBI was excellent (ICC2,2 = 0.85, SEM 0.07). CONCLUSIONS: Based on these results, interrater and intrarater reliability of PPG is excellent for measuring toe blood pressure, good for TBI and only fair for brachial pressures in people with diabetes mellitus.

Self-perceived risk of HIV infection and attitudes about preexposure prophylaxis among sexually transmitted disease clinic attendees in South Carolina.

Several domestic and international trials of the use of preexposure prophylaxis (PrEP) for HIV prevention are ongoing among groups at high risk for HIV infection. The objective of this cross-sectional study was to assess self-perceived risk of HIV infection and attitudes about PrEP among 405 sexually transmitted disease (STD) clinic attendees in South Carolina. Self-percieved risk of HIV infection and attitudes about PrEP were assessed using three questions from a self-administered survey. Ordinal logistic regression and logistic regression were used to evaluate differences in risk perception for HIV infection and attitudes about the use of PrEP among risk groups. Compared to heterosexual participants, homosexual participants were significantly more likely to have knowledge of PrEP (odds ratio [OR]=6.7, 95% confidence interval [CI]: 1.70-26.1). Compared to those participants who had 1 sexual partner in the past 3 months, individuals who had 2 to 4 sexual partners in the past 3 months were approximately 2.35 times as likely to have a lower level of agreement with the statement "I believe I am at risk of getting HIV" (p=0.0003). Compared to female participants, respondents who were male were approximately 2.8 times as likely to have a lower level of agreement with the statement "If I had to it would be very difficult for me (or my partner) to both use condoms and take daily pills to prevent HIV infection" (p<0.0001). These results suggest the need for the creation of PrEP implementation programs that are tailored to self-perceived risk perception, age, and gender.