Patients Undergoing Joint Replacement Surgery Research Articles

Prehabilitation: A proactive approach to enhancing outcomes in joint replacement surgery

Prehabilitation is an emerging proactive and preventive approach to healthcare that focuses on preparing individuals for upcoming medical interventions or procedures. It aims to optimize physical and mental health before the planned medical and surgical interventions. By integrating exercise, psychological support, and lifestyle modifications, prehabilitation empowers individuals to face medical interventions with increased resilience and a higher likelihood of successful outcomes. Prehabilitation helps patients build strength and endurance, which can enhance their ability to withstand the physical stress of surgery and contribute to faster recovery. It plays a crucial role in optimizing outcomes for patients undergoing joint replacement surgery, by enhancing postoperative recovery, reducing complications, and improving the overall quality of life for patients. As the field of orthopaedics continues to evolve, the integration of prehabilitation into standard care protocols has the potential to redefine the landscape of joint replacement surgeries, ultimately improving patient outcomes, and hence more research is required from diverse population groups from developed and developing countries to collate required data and formulate evidence-based clinical guidelines.

Research

The December 2023 Research Roundup360 looks at: Tissue integration and chondroprotective potential of acetabular labral augmentation with autograft tendon: study of a porcine model; The Irish National Orthopaedic Register under cyberattack: what happened, and what were the consequences?; An overview of machine learning in orthopaedic surgery: an educational paper; Beware of the fungus…; New evidence for COVID-19 in patients undergoing joint replacement surgery.

The Impact of the COVID-19 Pandemic on the Practice of Hip and Knee Arthroplasty

» The COVID-19 global pandemic resulted in unprecedented disruptions in care including massive surgical cancelations, a shift to outpatient surgery, and novel medical risks posed by COVID-19 infection on patients undergoing joint replacement surgery.» Refined patient optimization pathways have facilitated safe, efficient outpatient total joint arthroplasty in patient populations that may not otherwise have been considered eligible.» Rapid innovations emerged to deliver care while minimizing the risk of disease transmission which included the widespread adoption of telemedicine and virtual patient engagement platforms.» The widespread adoption of virtual technology was similarly expanded to resident education and continuing medical activities, which has improved our ability to propagate knowledge and increase access to educational initiatives.» Novel challenges borne of the pandemic include profound personnel shortages and supply chain disruptions that continue to plague efficiencies and quality of care in arthroplasty and require creative, sustainable solutions.

Differential effect of lactate on synovial fibroblast and macrophage effector functions.

The synovial membrane is the main site of inflammation in rheumatoid arthritis (RA). Here several subsets of fibroblasts and macrophages, with distinct effector functions, have been recently identified. The RA synovium is hypoxic and acidic, with increased levels of lactate as a result of inflammation. We investigated how lactate regulates fibroblast and macrophage movement, IL-6 secretion and metabolism via specific lactate transporters. Synovial tissues were taken from patients undergoing joint replacement surgery and fulfilling the 2010 ACR/EULAR RA criteria. Patients with no evidence of degenerative or inflammatory disease were used as control. Expression of the lactate transporters SLC16A1 and SLC16A3 on fibroblasts and macrophages was assessed by immunofluorescence staining and confocal microscopy. To test the effect of lactate in vitro we used RA synovial fibroblasts and monocyte-derived macrophages. Migration was assessed via scratch test assays or using trans-well inserts. Metabolic pathways were analysed by Seahorse analyser. IL-6 secretion was determined by ELISA. Bioinformatic analysis was performed on publicly available single cell and bulk RNA sequencing datasets. We show that: i) SLC16A1 and SLC16A3 which regulate lactate intake and export respectively, are both expressed in RA synovial tissue and are upregulated upon inflammation. SLC16A3 is more highly expressed by macrophages, while SLC16A1 was expressed by both cell types. ii) This expression is maintained in distinct synovial compartments at mRNA and protein level. iii) Lactate, at the concentration found in RA joints (10 mM), has opposite effects on the effector functions of these two cell types. In fibroblasts, lactate promotes cell migration, IL-6 production and increases glycolysis. In contrast macrophages respond to increases in lactate by reducing glycolysis, migration, and IL-6 secretion. In this study, we provide the first evidence of distinct functions of fibroblasts and macrophages in presence of high lactate levels, opening new insights in understanding the pathogenesis of RA and offering novel potential therapeutic targets.

A retrospective study of risk factors, causative micro-organisms and healthcare resources consumption associated with prosthetic joint infections (PJI) using the Clinical Practice Research Datalink (CPRD) Aurum database.

Prosthetic joint infection (PJI) is a serious complication after joint replacement surgery and it is associated with risk of mortality and morbidity along with high direct costs. The Clinical Practice Research Datalink (CPRD) data were utilized to quantify PJI incidence after hip or knee replacement up to 5 years after implant and a variety of risk factors related to patient characteristics, medical and treatment history along with characteristics of the original surgery were analyzed through Cox proportional hazard. 221,826 patients (individual joints 283,789) met all the inclusion and exclusion criteria of the study; during the study follow-up period (5 years), 707 and 695 PJIs were diagnosed in hip and knee, respectively. Patients undergoing joint replacement surgery during an unscheduled hospitalization had greater risk of PJI than patients whose surgery was elective; similarly, the risk of developing PJI after a secondary hip or knee replacement was about 4 times greater than after primary arthroplasty when adjusted for all other variables considered. A previous diagnosis of PJI, even in a different joint, increased the risk of a further PJI. Distribution of average LoS per each hospitalization caused by PJI exhibited a right skewed profile with median duration [IQR] duration of 16 days [8-32] and 13 days [7.25-32] for hip and knee, respectively. PJIs causative micro-organisms were dependent on the time between initial surgery and infection offset; early PJI were more likely to be multispecies than later (years after surgery); the identification of Gram- pathogens decreased with increasing post-surgery follow-up. This study offers a contemporary assessment of the budgetary and capacity (number and duration of hospitalizations along with the number of Accident and Emergency (A&E) visits) posed by PJIs in UK for the national healthcare system (NHS). The results to provide risk management and planning tools to health providers and policy makers in order to fully assess technologies aimed at controlling and preventing PJI. The findings add to the existing evidence-based knowledge surrounding the epidemiology and burden of PJI by quantifying patterns of PJI in patients with a relatively broad set of prevalent comorbidities.

Construction and validation of postoperative hypothermia prediction model for patients undergoing joint replacement surgery.

To construct and validate a postoperative hypothermia prediction model for patients undergoing joint replacement surgery. Postoperative hypothermia is one of the harmful perioperative complications in patients undergoing joint replacement surgery. The previous studies mainly focused on intraoperative hypothermia prediction models. The prediction model for postoperative hypothermia in patients with joint replacement surgery was understudied. Cohort study. We collected data from 503 participants undergoing joint replacement surgery in a tertiary hospital from January 2019 to December 2021. Of those, 404 cases were assigned to the modelling and 99 to the validation groups. Logistic regression was used to construct the model. The AUC was used to test the predictive effect of the model. Finally, 99 cases were used to verify the application effect of the model. A TRIPOD checklist was used to guide the reporting of this study. The factors entered into the prediction model were age, intraoperative hypothermia, BMI, heat preservation measures and platelet (PLT). The model was constructed as follows: Logit (P)=.537 + 3.669 × 1 (intraoperative hypothermia) + .030 × age - .289 × BMI + 2.857 × 1 (intraoperative insulation measures) + .003 × PLT. Hosmer-Lemeshow test, p=.608, the area under the receiver operating characteristic curve (AUC) was .861. The Youden index was .530, the sensitivity was .599 and the specificity was .93. The incidence of postoperative hypothermia in the modelling group was 42.93% (173/404), and that in the verification group was 43.43% (43/99), χ2=.012, p=.912. The correct practical application rate was 87.88%. This model has a good application effect. The current prediction model provided a reference for clinical screening of patients with high-risk hypothermia after joint replacement surgery. Clinical nurses can use the developed prediction model to predict the occurrence of postoperative hypothermia and provide a reference for the preventive measure.

A mobile application-based home assessment tool for patients undergoing joint replacement surgery: A qualitative feasibility study

BackgroundMost adults prefer to age in place. However, the majority of homes are not designed to support resident needs, especially for adults undergoing joint replacement surgeries such as total knee arthroplasty (TKA) or total hip arthroplasty (THA). It is of paramount importance to proactively assess and modify the homes of adults undergoing TKA/THA such that they can safely transition home following surgery. Several tools utilize emerging technology like virtual reality, augmented reality, or teleconferencing to assess home environments. These are meant to be used by professionals like occupational therapists. However, the acceptance and uptake of simple technology like mobile applications for assessing homes proactively by residents has not been explored. ObjectiveA qualitative exploratory study was conducted to evaluate the feasibility and potential acceptance of a mobile application for resident-initiated home assessment. MethodsSemi-structured interviews were conducted with 22 patient-care partner dyads before and after THA/TKA to understand the perceived usefulness, likelihood of using a mobile application-based home assessment tool, and perceived barriers and facilitators of using the tool. ResultsAbout 68% of the patient-care partner dyads interviewed for this study perceived benefits of using a mobile application-based tool. All the participants who perceived the tool to be useful showed high likelihood of using it. A comparison of responses between pre-and post-surgery interviews revealed that around 50% of participants showed an increased intention of using an assessment tool after experiencing challenges in their homes post-surgery. Participants provided recommendations for key content, potential features to include in the assessment tool, and preferred formats (e.g., checklists, visuals, and videos). ConclusionsTo increase acceptance of a mobile application-based home assessment tool, it is crucial that residents are made aware of the home environment challenges and the importance of an assessment tool to improve their safety and independence. The content, features, formats, and usability suggestions from the participants in this study provide a framework for health mobile application and interface developers to design a home assessment tool.

AN EPIGENOME-WIDE VIEW OF OSTEOARTHRITIS IN PRIMARY TISSUES

Purpose: Osteoarthritis (OA) is a complex degenerative joint disease. To promote the development of novel, efficient therapeutic approaches, it is first necessary to unravel the genomic architecture of osteoarthritis. Here, we investigate genome-wide DNA methylation from macroscopically intact (low-grade) and degraded (high-grade) osteoarthritis cartilage, as well as synovium tissue from a total of 98 knee osteoarthritis patients undergoing joint replacement surgery. We aimed to (1) characterize methylation markers of cartilage degeneration, (2) identify genotype-dependent methylation changes (mQTL effects), and (3) investigate causal effects of methylation loci on OA.

Introducing Virtual Prehabilitation to a UK Elective Total Hip Replacement service to improve patient outcomes: An overview of the literature and proposed implementation plan

Elective Total Hip Replacement (THR) surgery is one of the most common elective surgeries in the UK, costing the National Health Service (NHS) over £300,000,000 annually. A review of the literature identified preoperative rehabilitation, known as ‘prehabilitation’, improves patient outcomes and decreases Length Of hospital Stay (LOS). This approach follows NICE guidelines which recommend prehabilitation for all patients undergoing joint replacement surgery. Challenges accessing prehabilitation classes at UK hospitals due to inadequate transport and COVID-19 restrictions present an opportunity to provide prehabilitation virtually. Physiotherapy services are increasingly utilising technology, in line with The NHS Long Term Plan to increase service accessibility. A review of the literature has established virtual prehabilitation is effective, feasible, and preferable for patients. Quality Improvement methodology has been used to propose an implementation plan for a virtual prehabilitation service. Further research is required to create a standardised prehabilitation protocol, and to assess the long-term effects and sustainability of virtual prehabilitation.

Post-Discharge Clostridioides difficile Infection after Arthroplasties in Poland, Infection Prevention and Control as the Key Element of Prevention of C. difficile Infections.

Clostridioides difficile is still one of the most common causes of hospital-acquired infectious diarrhea (CDI), and the incidence of CDI is one of the indicators that allows conclusions to be derived on the correctness of antibiotic administration. The objective of this observational study was the analysis of post-discharge CDI incidence in patients undergoing hip or knee arthroplasty, in order to specify optimum conditions for the surgical procedures and outpatient postoperative care. One-year observational study. Public Polish hospitals. Retrospective records for 83,525 surgery patients having undergone hip or knee arthroplasty were extracted from the Polish National Health Fund databases. CDI and/or antibiotic prescriptions in the 30 day post-surgery period were expressed per 1000 surgeries with antibiotic prescription on discharge or in ambulatory care, respectively. The CDI incidence rate was 34.4 per 10,000 patients, and 7.7 cases per 100,000 post-surgery patient-days. Patients who were prescribed at least one antibiotic were diagnosed with CDI more often than patients who had no antibiotic treatment (55.0/1000 patients vs. 1.8/1000 patients). In the multifactorial analysis, the following factors were significant: being at least 65 years of age, trauma as the cause of surgery, length of stay over 7 days, HAIs other than CDI and taking beta-lactams and/or quinolones but not macrolides in the post-discharge period. Postoperative antibiotic prescription in patients undergoing joint replacement surgery is the main risk factor for CDI. These observations indicate the necessity of improvement of infection control programs as the key factor for CDI prevention.

The Analgesic Properties of a Music Intervention in the Post Anesthesia Care Unit

<h3>Introduction</h3> Twenty to 85% of surgical patients develop persistent postsurgical pain (PPP) following surgery. Listening to music has been shown to decrease pain scores and increase patient satisfaction in postoperative adult patients. <h3>Identification of the problem</h3> Under management of the severity and duration of acute postoperative pain in the post anesthesia care unit (PACU) is a significant risk factor for PPP and causes delays in discharge from the PACU. Evidence of the analgesic effects of music interventions suggest that listening to music has a positive effect on decreasing pain scores and increasing patient satisfaction in postoperative adult patients<i>.</i> <h3>The purpose of this study was to</h3> 1) determine whether a combined music pharmacological intervention was an effective multimodal approach to mitigate adult pain for patients undergoing joint replacement surgery in the PACU; and 2) measure the effect of music intervention on reducing PACU length of stay (LOS). <h3>Methodology</h3> A prospective, randomized control trial study design is proposed to determine whether a combined music pharmacologic intervention decreases discharge pain scores and decreases pain level delays to discharge from the PACU compared to pharmacological interventions alone. <h3>Results</h3> The study was completed December 2020. Dissemination of findings will occur by the end of 2021 months by submitting results to the Journal of Perianesthesia Nursing (JOPAN) for publication and presentation of findings at the national conference. <h3>Discussion</h3> Multiple lines of evidence demonstrate that music interventions are effective in decreasing a patient's perception of pain. <h3>Conclusion</h3> The lack of improvement in pain scores in the intervention group may be due, in part, to the low average pain scores participants in the study reported both upon admission and at discharge from the PACU. <h3>Implications for perianesthesia nurses and future research</h3> Further opportunities exist to test the effects of music intervention on patient and clinical outcomes immediately after surgery. Our results provide estimates for pain and PACU LOS to determine sample sizes for future randomized controlled trials. Future studies should also measure the benefits of music interventions with different surgical and anesthetic populations.

Impact of Patient Engagement on Tailored Education for Joint Replacement Population Using Technology.

Patient engagement and technology use for healthcare are important for optimal care. This study was designed to leverage technology in education among the adult joint population based on their engagement capacity and utilization of technology for care. A convenience sample of 80 patients undergoing joint replacement surgery and followed in the inpatient setting participated. Comparisons were made between an intervention group who completed the Person Engagement Index to measure their engagement capacity and received a technological educational plan based on their score versus those receiving the standard educational plan. The Person Engagement Index psychometrics were sound and indicated high engagement capacity. Overall, the groups did not differ in utilization, satisfaction, and education comprehension; however, the intervention group reported a higher unit mean for the extent they felt ready for discharge and instructions for care at home. Results of this study informed patients' engagement capacity and technology use for pre-/postoperative education for procedure expectations and self-management throughout the joint replacement process and recovery. Future research includes use of technology for engagement capacity and outcomes with other populations, collecting socio-demographic data to determine differences among groups and examining the patient and provider experience and satisfaction with using technology to enhance care and outcomes.

Are responders to patient health surveys representative of those invited to participate? An analysis of the Patient-Reported Outcome Measures Pilot from the Australian Orthopaedic Association National Joint Replacement Registry.

Patient-reported outcome measures (PROMs) are commonly used to evaluate surgical outcome in patients undergoing joint replacement surgery, however routine collection from the target population is often incomplete. Representative samples are required to allow inference from the sample to the population. Although higher capture rates are desired, the extent to which this improves the representativeness of the sample is not known. We aimed to measure the representativeness of data collected using an electronic PROMs capture system with or without telephone call follow up, and any differences in PROMS reporting between electronic and telephone call follow up. Data from a pilot PROMs program within a large national joint replacement registry were examined. Telephone call follow up was used for people that failed to respond electronically. Data were collected pre-operatively and at 6 months post-operatively. Responding groups (either electronic only or electronic plus telephone call follow up) were compared to non-responders based on patient characteristics (joint replaced, bilaterality, age, sex, American Society of Anesthesiologist (ASA) score and Body Mass Index (BMI)) using chi squared test or ANOVA, and PROMs for the two responder groups were compared using generalised linear models adjusted for age and sex. The analysis was restricted to those undergoing primary elective hip, knee or shoulder replacement for osteoarthritis. Pre-operatively, 73.2% of patients responded electronically and telephone follow-up of non-responders increased this to 91.4%. Pre-operatively, patients responding electronically, compared to all others, were on average younger, more likely to be female, and healthier (lower ASA score). Similar differences were found when telephone follow up was included in the responding group. There were little (if any) differences in the post-operative comparisons, where electronic responders were on average one year younger and were more likely to have a lower ASA score compared to those not responding electronically, but there was no significant difference in sex or BMI. PROMs were similar between those reporting electronically and those reporting by telephone. Patients undergoing total joint replacement who provide direct electronic PROMs data are younger, healthier and more likely to be female than non-responders, but these differences are small, particularly for post-operative data collection. The addition of telephone call follow up to electronic contact does not provide a more representative sample. Electronic-only follow up of patients undergoing joint replacement provides a satisfactory representation of the population invited to participate.

ENAMPT Is Localised to Areas of Cartilage Damage in Patients with Hip Osteoarthritis and Promotes Cartilage Catabolism and Inflammation.

Obesity increases the risk of hip osteoarthritis (OA). Recent studies have shown that adipokine extracellular nicotinamide phosphoribosyltransferase (eNAMPT or visfatin) induces the production of IL-6 and matrix metalloproteases (MMPs) in chondrocytes, suggesting it may promote articular cartilage degradation. However, neither the functional effects of extracellular visfatin on human articular cartilage tissue, nor its expression in the joint of hip OA patients of varying BMI, have been reported. Hip OA joint tissues were collected from patients undergoing joint replacement surgery. Cartilage explants were stimulated with recombinant human visfatin. Pro-inflammatory cytokines and MMPs were measured by ELISA and Luminex. Localisation of visfatin expression in cartilage tissue was determined by immunohistochemistry. Cartilage matrix degradation was determined by quantifying proteoglycan release. Expression of visfatin was elevated in the synovial tissue of hip OA patients who were obese, and was co-localised with MMP-13 in areas of cartilage damage. Visfatin promoted the degradation of hip OA cartilage proteoglycan and induced the production of pro-inflammatory cytokines (IL-6, MCP-1, CCL20, and CCL4) and MMPs. The elevated expression of visfatin in the obese hip OA joint, and its functional effects on hip cartilage tissue, suggests it plays a central role in the loss of cartilage integrity in obese patients with hip OA.

Higher PGD2 production by synovial mast cells from rheumatoid arthritis patients compared with osteoarthritis patients via miR-199a-3p/prostaglandin synthetase 2 axis

We previously reported that synovial mast cells (MCs) from patients with rheumatoid arthritis (RA) produced TNF-α in response to immune complexes via FcγRI and FcγRIIA. However, the specific functions of synovial MCs in RA remain unclear. This study aimed to elucidate those functions. Synovial tissues and fluid were obtained from RA and osteoarthritis (OA) patients undergoing joint replacement surgery. Synovium-derived, cultured MCs were generated by culturing dispersed synovial cells with stem cell factor. We performed microarray-based screening of mRNA and microRNA (miRNA), followed by quantitative RT-PCR-based verification. Synovial MCs from RA patients showed significantly higher prostaglandin systhetase (PTGS)1 and PTGS2 expression compared with OA patients’ MCs, and they produced significantly more prostaglandin D2 (PGD2) following aggregation of FcγRI. PGD2 induced IL-8 production by human group 2 innate lymphoid cells, suggesting that PGD2-producing MCs induce neutrophil recruitment into the synovium of RA patients. PTGS2 mRNA expression in RA patients’ MCs correlated inversely with miRNA-199a-3p expression, which down-regulated PTGS2. RA patients’ synovial fluid contained significantly more PGD2 compared with OA patients’ fluid. Synovial MCs might regulate inflammation in RA through hyper-production of PGD2 following FcRγ aggregation. Our findings indicate functional heterogeneity of human MCs among diseases.

Vitamin C in orthopedic practices: Current concepts, novel ideas, and future perspectives

Vitamin C (ascorbic acid), is an important antioxidant that has been applied broadly in the field of orthopaedics. Current research on vitamin C examines the molecule's role in bone and tendon physiology, as well as joint replacement and Postoperative pain. Most laboratory and human studies associate the use of vitamin C with improved bone health and tendon healing. Recent literature moderately supports the use of vitamin C to improve functional outcomes, decreased postoperative pain, and prevent complex regional pain syndrome following orthopaedic procedures. The perioperative use of vitamin C in patients undergoing joint replacement surgery and anterior cruciate ligament reconstruction is still under investigation. Overall, there is need for high-quality human trials to confirm whether vitamin C can potentiate the outcomes of orthopaedic procedures and to determine optimal dosage and means of administration to maximize its proposed benefits. The purpose of this review was to summarize the application of vitamin C in orthopaedic practices and to identify potential areas for future study.

Reengineering Bone-Implant Interfaces for Improved Mechanotransduction and Clinical Outcomes.

The number of patients undergoing joint replacement surgery has progressively increased worldwide due to world population ageing. In the Unites States, for example, the prevalence of hip and knee replacements has increased more than 6 and 10 times, respectively, since 1980. Despite advances in orthopaedic implant research, including the development of novel implantable biomaterials, failures are still observed due to inadequate biomechanical compliance at the bone-implant interface. This comprises static and dynamic mechanical mismatch between the bone and the implant surface. The importance and robustness of biomechanical cues for controlling osteogenic differentiation of mesenchymal stem cells (MSC) have been highlighted in recent studies. However, in the context of bone regenerative medicine, it remains elusive how mechanobiological signals controlling MSC osteogenic differentiation dynamics are modulated in their interaction with the bone and with implants. In this review, we highlight recent technological advances aiming to improve host bone-implant interactions based on the osteogenic and mechanoresponsive potential of MSC, in the context of joint replacement surgery. First, we discuss the extracellular and intracellular mechanical forces underlying proper receptivity and stimulation of physiological MSC differentiation and linked osteogenic activity. Second, we provide a critical overview on how this knowledge can be integrated towards the development of biomaterials for improved bone-implant interfaces. Third, we discuss cross-disciplinarily which contributes to the next generation design of novel pro-active orthopaedic implants and their implantation success. Graphical Abstract.

Immunosuppression and the risk of readmission and mortality in patients with rheumatoid arthritis undergoing hip fracture, abdominopelvic and cardiac surgery

ObjectivesThe impact of immunosuppression on postoperative outcomes has primarily been studied in patients undergoing joint replacement surgery. We aimed to evaluate the impact of biologics and glucocorticoids on outcomes after...

Interventions for Obesity and Nutritional Status in Arthroplasty Patients.

Nutritional risk in patients undergoing total joint arthroplasty has been well-studied with regard to diagnostic criteria; however, therapeutic management of abnormal body mass index (BMI) values and serum markers remains to be studied in patients undergoing joint replacement surgery. Patients with a BMI value of >40 kg/m2 are at increased risk for postoperative complications; weight loss programs and bariatric surgery are therapeutic modalities that can be used in the prehabilitation and long-term rehabilitation of patients undergoing total joint arthroplasty. Management of patients with abnormal nutritional status should be multidisciplinary and allow for the incorporation of dietitians and nutritionists in therapeutic planning. Hypoalbuminemia correction can be completed intravenously or orally; however, arthroplasty studies remain lacking with regard to the preferred modalities of correction.

Effects of immersive virtual reality therapy on intravenous patient-controlled sedation during orthopaedic surgery under regional anesthesia: A randomized controlled trial.

BackgroundImmersive virtual reality (IVR) is a form of distraction therapy that has shown potential as an analgesia and sedation sparing agent. This study assessed the effect of IVR on the self-administered sedation requirements of patients undergoing joint replacement surgery under regional anesthesia in a single center.Methods and findingsThis study was a single-center, randomized control trial at St Vincent’s Hospital in Melbourne, Australia. Fifty patients undergoing elective total knee and total hip arthroplasty were randomized to IVR and Propofol patient-controlled sedation (PCS) or propofol PCS alone. The primary outcome measure was intra-operative propofol use. Secondary outcomes included pattern of propofol use over time, use of adjunct analgesia, unmet propofol demand, and patient satisfaction survey scores. Of 50 total patients, 25 received IVR in conjunction with PCS, and 25 received PCS alone. All patients received adjunct analgesia from the treating Anesthesiologist. Median propofol use/hour over the entire procedure in the control group was 40 (11.1, 93.9) mg/hour compared with 45 (0, 94.7) mg/hour in the IVR group (p = 0.90). There were no differences in patterns of propofol use over the course of each procedure. Adjusting for various baseline characteristics did not change the results. Postoperative satisfaction scores were equivalent in both groups. The VR intervention was well tolerated by all patients, with no report of major side effects. Key limitations were relatively small sample size, the non-blinded nature of the study, and use of adjunct analgesia.ConclusionsIn patients receiving joint replacement surgery under regional anesthesia with PCS, IVR was well tolerated but did not decrease the overall sedation requirement.