Preoperative Chronic Pain as a Risk Factor for Early Postoperative Cognitive Dysfunction in Elderly Patients Undergoing Hip Joint Replacement Surgery: A Prospective Observational Cohort Study

Background: Although major joint replacement surgery has a high overall success rate, postoperative cognitive dysfunction (POCD) is a common complication after anesthesia and surgery, increasing morbidity and mortality. Identifying POCD risk factors would be helpful to prevent and decrease the occurrence of POCD. We hypothesized that preoperative chronic pain increases the risk of POCD.Methods: A single-center, observational, prospective cohort study was conducted from January 2018 to March 2020. All consecutive elderly patients (>65 years) who underwent elective total hip arthroplasty or hemiarthroplasty with general anesthesia by the same surgeon were enrolled. The patients underwent neuropsychological testing preoperatively and at 7 days and 2 months after surgery. To determine POCD, a nonsurgical control group was recruited from the general community.Results: Of the 141 patients who finished the neuropsychological testing 7 days after surgery, 61 (43.2%) had preoperative chronic pain. Of the 61 patients, 17 (27.9%) developed POCD; of the 79 patients with no chronic pain, 10 (12.7%) had developed POCD by 7 days after surgery. Multivariate logistic regression analysis identified preoperative chronic pain as a risk factor of POCD assessed 7 days after surgery (odds ratio 6.527; P = 0.009). There was no significant difference in the POCD incidence 2 months after surgery between patients with and without preoperative chronic pain.Conclusion: Preoperative chronic pain was a risk factor of developing POCD within 7 days after surgery in elderly patients following hip joint replacement surgery.Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [NCT03393676].

A comparison of three strategies to reduce the burden of osteoarthritis: A population-based microsimulation study

Objectives The purpose of this study was to compare three strategies for reducing population health burden of osteoarthritis (OA): improved pharmacological treatment of OA-related pain, improved access to joint replacement surgery, and prevention of OA by reducing obesity and overweight. Methods We applied a validated computer microsimulation model of OA in Canada. The model simulated a Canadian-representative open population aged 20 years and older. Variables in the model included demographics, body mass index, OA diagnosis, OA treatment, mortality, and health-related quality of life. Model parameters were derived from analyses of national surveys, population-based administrative data, a hospital-based cohort study, and the literature. We compared 8 what-if intervention scenarios in terms of disability-adjusted life years (DALYs) relative to base-case, over a wide range of time horizons. Results Reductions in DALYs depended on the type of intervention, magnitude of the intervention, and the time horizon. Medical interventions (a targeted increase in the use of painkillers) tended to produce effects quickly and were, therefore, most effective over a short time horizon (a decade). Surgical interventions (increased access to joint replacement) were most effective over a medium time horizon (two decades or longer). Preventive interventions required a substantial change in BMI to generate a significant impact, but produced more reduction in DALYs than treatment strategies over a very long time horizon (several decades). Conclusions In this population-based modeling study we assessed the potential impact of three different burden reduction strategies in OA. Data generated by our model may help inform the implementation of strategies to reduce the burden of OA in Canada and elsewhere.

3D Printing of Temporary Prostheses for Controlled-Release of Drugs: Design, Physical Characterization and Preliminary Studies

In recent years, the use of 3D printing technologies in orthopedic surgery has markedly increased, as they offer the possibility of printing personalized prostheses. The work presented in this article is a preliminary study of a research project which aims to manufacture customized spacers containing antibiotics for use in joint replacement surgery. The objective of this work was to design and print different 3D constructs to evaluate the use of different materials, their properties after the process of 3D printing, such as resistance, and the release kinetics of drugs from the constructs. Different designs and different materials were analyzed to obtain a 3D construct with suitable properties. Our design takes advantage of the micropores created between the layers of the 3D printed filaments to release the contained drug. Using polylactic acid (PLA) we were able to print cylindrical structures with interconnected micropores and a hollow chamber capable of releasing methylene blue, which was selected as a model drug. The final PLA 3D construct was printed with a 10% infill. The physical and technological characteristics, morphological changes at body temperature and interaction with water were considered to be acceptable. The PLA 3D printed constructs were found to have sufficient strength to withstand a force of 500 kg. The results obtained allow to continue research in this project, with the aim of manufacturing prostheses containing a reservoir of antibiotics or other drugs in their interior for their subsequent controlled release.

Macrophage-biomimetic porous Se@SiO2 nanocomposites for dual modal immunotherapy against inflammatory osteolysis

Background Inflammatory osteolysis, a major complication of total joint replacement surgery, can cause prosthesis failure and necessitate revision surgery. Macrophages are key effector immune cells in inflammatory responses, but excessive M1-polarization of dysfunctional macrophages leads to the secretion of proinflammatory cytokines and severe loss of bone tissue. Here, we report the development of macrophage-biomimetic porous SiO2-coated ultrasmall Se particles (porous Se@SiO2 nanospheres) to manage inflammatory osteolysis. Results Macrophage membrane-coated porous Se@SiO2 nanospheres(M-Se@SiO2) attenuated lipopolysaccharide (LPS)-induced inflammatory osteolysis via a dual-immunomodulatory effect. As macrophage membrane decoys, these nanoparticles reduced endotoxin levels and neutralized proinflammatory cytokines. Moreover, the release of Se could induce macrophage polarization toward the anti-inflammatory M2-phenotype. These effects were mediated via the inhibition of p65, p38, and extracellular signal-regulated kinase (ERK) signaling. Additionally, the immune environment created by M-Se@SiO2 reduced the inhibition of osteogenic differentiation caused by proinflammation cytokines, as confirmed through in vitro and in vivo experiments. Conclusion Our findings suggest that M-Se@SiO2 have an immunomodulatory role in LPS-induced inflammation and bone remodeling, which demonstrates that M-Se@SiO2 are a promising engineered nanoplatform for the treatment of osteolysis occurring after arthroplasty. Graphical Abstract

Non-compliance with clinical guidelines increases the risk of complications after primary total hip and knee joint replacement surgery

Background Total hip and total knee replacement (THR/TKR) are common and effective surgeries to reduce the pain and disability associated with arthritis but are associated with small but significant risks of preventable complications such as surgical site infection (SSI) and venous-thrombo-embolism (VTE). This study aims to determine the degree to which hospital care was compliant with clinical guidelines for the prevention of SSI and VTE after THR/TKR; and whether non-compliant prophylaxis is associated with increased risk of complications. Methods and findings A prospective multi-centre cohort study was undertaken in consenting adults with osteoarthritis undergoing elective primary TKR/THR at one of 19 high-volume Australian public or private hospitals. Data were collected prior to surgery and for one-year post-surgery. Four adjusted logistic regression analyses were undertaken to explore associations between binary non-compliance and the risk of surgical complications: (1) composite (simultaneous) non-compliance with both (VTE and antibiotic) guidelines and composite complications [all-cause mortality, VTE, readmission/reoperation for joint-related reasons (one-year) and non-joint-related reasons (35-days)], (2) VTE non-compliance and VTE outcomes, (3) antibiotic non-compliance and any SSI, and (4) antibiotic non-compliance and deep SSI. Data were analysed for 1875 participants. Guideline non-compliance rates were high: 65% (VTE), 87% (antibiotics) and 95% (composite guideline). Composite non-compliance was not associated with composite complication (12.8% vs 8.3%, adjusted odds ratio [AOR] = 1.41, 95%CI 0.68–3.45, p = 0.40). Non-compliance with VTE guidelines was associated with VTE outcomes (5% vs 2.4%, AOR = 2.83, 95%CI 1.59–5.28,p < 0.001). Non-compliance with antibiotic guidelines was associated with any SSI (14.8% vs 6.1%, AOR = 1.98, 95%CI 1.17–3.62,p = 0.02) but not deep infection (3.7% vs 1.2%,AOR = 2.39, 95%CI 0.85–10.00, p = 0.15). Conclusions We found high rates of clinical variation and statistically significant associations between non-compliance with VTE and antibiotic guidelines and increased risk of VTE and SSI, respectively. Complications after THR/TKR surgery may be decreased by improving compliance with clinical guidelines.

Patient safety during joint replacement surgery: experiences of operating room nurses

BackgroundAvoidable complications for surgical patients still occur despite efforts to improve patient safety processes in operating rooms. Analysis of experiences of operating room nurses can contribute to better understanding of perioperative processes and flow, and why avoidable complications still occur.AimTo explore aspects of patient safety practice during joint replacement surgery through assessment of operating room nurse experiences.MethodA qualitative design using semistructured interviews with 21 operating room nurses currently involved in joint replacement surgery in Sweden. Inductive qualitative content analysis was used.ResultsThe operating room nurses described experiences with patient safety hazards on an organisational, team and individual level. Uncertainties concerning a reliable plan for the procedure and functional reporting, as well as documentation practices, were identified as important. Teamwork and collaboration were described as crucial at the team level, including being respected as valuable, having shared goals and common expectations. On the individual level, professional knowledge, skills and experience were needed to make corrective steps.ConclusionThe conditions to support patient safety, or limit complication risk, during joint replacement surgery continue to be at times inconsistent, and require steady performance attention. Operating room nurses make adjustments to help solve problems as they arise, where there are obvious risks for patient complications. The organisational patient safety management process still seems to allow deviation from established practice standards at times, and relies on individual-based corrective measures at the ‘bedside’ at times for good results.

The influence of hla genotype on the development of metal hypersensitivity following joint replacement

Joint replacement surgery provides pain relief and restoration of mobility for millions of patients around the world each year.[1] However, the release of wear debris from implant surfaces can limit the lifespan of a prosthesis through the promotion of inflammatory responses.[2] Implants must therefore be constructed from materials with sufficient durability and biocompatibility. One such material is cobalt chrome alloy, which is used in the majority of joint replacements.[3] Unfortunately, it is recognised that some patients develop lymphocyte mediated delayed type hypersensitivity (DTH) responses to this material,[4] a response which may result in extensive bone and soft tissue destruction.[5] A genetic predisposition to DTH has been proposed[6], though specific genes have yet to be identified, or the effects quantified. Here we show that variation in HLA class II genotype influences an individual’s susceptibility to DTH. HLA-DQ haplotypes encoding peptide binding grooves with greater affinity for the N terminal peptide sequence of albumin (containing two recognised metal binding sites) confer a greater risk of DTH. We describe the development and validation of a machine learning algorithm to investigate the possibility that a patient’s genotype and basic clinical parameters may be used to predict DTH. Incorporating this novel finding, gradient boosted survival analysis machine learning models were trained and validated using results from 606 patients from three international units. These models were assessed using Uno’s c-index, time-dependent AUROCs, and integrated calibration index performance statistics. At present, there are no tests in widespread clinical use which use a patient’s genetic profile to guide implant selection or inform post-operative management. The algorithm described herein may address this issue.

Sarcopenia index based on serum creatinine and cystatin C predicts the risk of postoperative complications following hip fracture surgery in older adults

Objective To assess the utility of the preoperative Sarcopenia index (SI) as a predictive marker of the risk of postoperative complications following hip fracture surgery in older adults. Study design This observational study enrolled older adults with hip fracture who were hospitalized in the Department of Orthopedics of West China Hospital, Sichuan University, from December 7, 2010 - June 14, 2017, and who underwent hip fracture surgery. Primary outcome and measures Clinical data were collected from medical records and serum creatinine and cystatin C were measured before surgery. Outcomes included postoperative complications such as pneumonia, urinary tract infection, respiratory failure, heart failure, and non-grade A healing. Binary logistic regression analyses were used to analyze association between SI and postoperative complications. Results A total of 897 patients aged 60 years and over were enrolled in this study (age range: 60 – 100 years), of whom 306(34.1%)were male, and 591(65.9%)were female. Postoperative complications included pneumonia (12%), urinary tract infections (1.8%), respiratory failure (1.5%), heart failure (1.6%), and non-A- grade healing (3.6%). In the patient group that received joint replacements, the incidence of pneumonia was negatively associated with SI values. After adjusting for potential confounding factors, binary logistic regression analyses showed that a higher SI was independently associated with a lower risk of pneumonia after joint replacement surgery (OR:0.39, 95% CI:0.18-0.89, P<0.05). However, we did not find statistically significant association between SI and the risk of postoperative complications other than pneumonia among patients with two types of hip fracture surgery. Conclusion The SI based on serum creatinine and cystatin C can predict pneumonia rather than other postoperative complications among older patients with hip fracture after joint replacement surgery.

Multimodality imaging in shoulder arthroplasties Part 2: Immediate pre- and intra-operative imaging and imaging of early and late complications – A pictorial review

Shoulder arthroplasty imaging requires a thorough understanding of surgical techniques, biomechanics involved during and after the joint replacement surgery and complications unique to shoulder arthroplasties. One may believe that imaging of complications requires excessive complex imaging modalities such as MRI or nuclear imaging. However, contrary to such beliefs, one can diagnose such complications mostly on radiographs. We will describe advances in immediate pre-operative imaging and utility of imaging to diagnose shoulder arthroplasty- related complications in part 2 of our two-part pictorial review series.