The American Joint Replacement Registry-the first 5 years

Which Interventions Are Effective in Treating Sleep Disturbances After THA or TKA? A Systematic Review

BACKGROUND

Poor sleep quality is a common complaint after total joint arthroplasty (TJA), and it is associated with reports of higher pain and worse functional outcomes. Several interventions have been investigated with the intent to reduce the incidence of postoperative sleep disturbance with varying effectiveness. An aggregate of the best available evidence, along with an evaluation of the quality of those studies, is needed to provide valuable perspective to physicians and to direct future research.

QUESTIONS/PURPOSES

In this systematic review, we asked: (1) What is the reported efficacy of the most commonly studied medications and nonpharmacologic approaches, and (2) what are their side effects and reported complications?

METHODS

This systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search using a combination of controlled vocabulary and keywords was performed utilizing Medline (Ovid), Embase (Ovid), Cochrane Central, and Web of Science databases from database inception to 2023, with the last search occurring October 24, 2023, to identify studies that evaluated a sleep intervention on the effect of patient-reported sleep quality after THA or TKA. Inclusion criteria were clinical trials, comparative studies, and observational studies on adult patients who underwent primary TKA or THA for osteoarthritis and who completed validated sleep questionnaires to assess sleep quality postoperatively. We excluded studies on patients younger than 18 years, patients with sleep apnea, TKA or THA because of trauma or conditions other than osteoarthritis, revision TJA, studies in languages other than English, and studies from nonindexed journals or preprint servers. Two investigators independently screened 1535 studies for inclusion and exclusion criteria and extracted data from the included studies. Ultimately, 14 studies were included in this systematic review, including 12 randomized controlled trials and 2 prospective comparative studies. A total of 2469 participants were included, with a mean ± SD age of 65 ± 7 years and 38% men in control groups and 65 ± 7 years and 39% men in intervention groups. Sleep quality questionnaires utilized included the Pittsburgh Sleep Quality Index, Self-Rating Scale of Sleep, 100-mm VAS - Sleep, Sleep Disturbance Numeric Rating Scale, Likert scales, and one institutionally designed questionnaire. Quality analysis was performed utilizing the Joanna Briggs Institute (JBI) Critical Appraisal Checklist for Randomized Controlled Trials, where higher scores of 13 indicated a more reliable study, and the Newcastle-Ottawa Quality Assessment Scale for Cohort Studies, where higher scores of 9 indicated a more reliable study and scores < 5 represented a high risk of bias. Two of the randomized controlled trials scored a 12 of 13, and the remaining 10 met every criteria of the JBI checklist. Both comparative studies scored 5 of 9 possible points of the Newcastle-Ottawa Scale.

RESULTS

Melatonin and selective cyclooxygenase-2 inhibitor rofecoxib were found to provide a clinically important benefit to sleep quality within the first postoperative week after TJA. However, rofecoxib was withdrawn from the market globally in 2004 over concerns about increased risk of cardiovascular events. Another cyclooxygenase-2 inhibitor, celecoxib, remains available. No other intervention demonstrated a clinical benefit. Side effects of melatonin include dizziness, headache, paresthesia, and nausea, and it is contraindicated in patients with liver failure, autoimmune conditions, or who are receiving warfarin. Long-term adverse effects of rofecoxib include hypertension, edema, and congestive heart failure, and it is contraindicated in patients with renal insufficiency or who are receiving warfarin. Melatonin is considered safe in older patients, but more caution should be taken with rofecoxib.

CONCLUSION

Owing to limited evidence in support of most of the interventions we studied, none of these interventions can be recommended for routine use after TJA. Melatonin and rofecoxib may provide a benefit to sleep quality in some patients, but physicians need to understand the adverse effects and contraindications before recommending these interventions. Additionally, rofecoxib is no longer commercially available. Future investigation is warranted to evaluate the effectiveness of interventions with minimal side effect profiles for providers to be able to make an informed decision about interventions for sleep improvement after TJA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Optimizing alkaline hydrothermal treatment for biomimetic smart metallic orthopedic and dental implants

Orthopedic and dental implant failure continues to be a significant concern due to localized bacterial infections. Previous studies have attempted to improve implant surfaces by modifying their texture and roughness or coating them with antibiotics to enhance antibacterial properties for implant longevity. However, these approaches have demonstrated limited effectiveness. In this study, we attempted to engineer the titanium (Ti) alloy surface biomimetically at the nanometer scale, inspired by the cicada wing nanostructure using alkaline hydrothermal treatment (AHT) to simultaneously confer antibacterial properties and support the adhesion and proliferation of mammalian cells. The two modified Ti surfaces were developed using a 4 h and 8 h AHT process in 1 N NaOH at 230 °C, followed by a 2-hour post-calcination at 600 °C. We found that the control plates showed a relatively smooth surface, while the treatment groups (4 h & 8 h AHT) displayed nanoflower structures containing randomly distributed nano-spikes. The results demonstrated a statistically significant decrease in the contact angle of the treatment groups, which increased wettability characteristics. The 8 h AHT group exhibited the highest wettability and significant increase in roughness 0.72 ± 0.08 µm (P < 0.05), leading to more osteoblast cell attachment, reduced cytotoxicity effects, and enhanced relative survivability. The alkaline phosphatase activity measured in all different groups indicated that the 8 h AHT group exhibited the highest activity, suggesting that the surface roughness and wettability of the treatment groups may have facilitated cell adhesion and attachment and subsequently increased secretion of extracellular matrix. Overall, the findings indicate that biomimetic nanotextured surfaces created by the AHT process have the potential to be translated as implant coatings to enhance bone regeneration and implant integration.

Results of a monocentric field study: value of histology compared to sonication method and conventional tissue culture in the diagnosis of periprosthetic joint infection (PJI)

BACKGROUND

To confirm the diagnosis of periprosthetic joint infection (PJI), the Infectious Diseases Society of America (IDSA) and the International Consensus Meeting (ICM) have defined criteria that include histology as a minor criterion and the sonication method only as an additional criterion. The aim of this monocentric, retrospective study was to investigate the value of histology and whether sonication leads to a more accurate diagnosis.

MATERIALS AND METHODS

All revision surgeries for knee and hip arthroplasty between 2017 and 2020 were included. With regard to microbiological diagnostic, conventional culture of periprosthetic biopsies and sonication of explant material were performed. In addition, histology and non-specific inflammatory markers (CRP, leukocytes) were recorded.

RESULTS

A total of 78 patients with PJI and 62 aseptic controls were included. From both microbiological methods (conventional culture / sonication), Staphyloccus (S.) epidermidis and S. aureus were detected most frequently. However, compared to the conventional microbiology, a higher sensitivity was calculated for sonication, albeit with a lower specificity in relation to a PJI. In two logistic regression models for the significance of all diagnostic parameters in PJI, the AUC was 0.92 and 0.96 with histology in particular making the decisive contribution in both models (p < 0. 001, both models).

CONCLUSION

Since histology showed the highest accuracy in the current study, its importance in the PJI criteria should be reevaluated. Sonication shows a high sensitivity for germ detection with a lower specificity and should only be used in combination with the conventional culture for microbiolgical diagnostics.

Experience of an anatomic femoral stem in a UK orthopaedic centre beyond 20 years of follow-up

INTRODUCTION

Increasing interest in the use of anatomical stems has developed as the prevalence of periprosthetic fractures (PPFs) continues to increase. The primary aim of this study was to determine the long-term survivorship and PPF rate of an anatomical femoral stem in a single UK centre.

PATIENTS AND METHODS

Between 2000 and 2002, 94 consecutive THAs were performed using the 170 mm Lubinus SP II anatomical femoral stem in our institution. Patient demographics, operative details and clinical outcomes were collected prospectively in an arthroplasty database. Patient records and national radiographic archives were reviewed finally at a mean of 21.5 years (SD 0.7) following surgery to identify occurrence of subsequent revision surgery, dislocation or periprosthetic fracture.

RESULTS

Mean patient age at surgery was 65.8 years (SD 12.5, 34-88 years). There were 48 women (51%). Osteoarthritis was the operative indication in 88 patients (94%). Analysis of all-cause THA failure demonstrated a survivorship of 98.5% (95% confidence interval [CI], 98.0-99.3%) at 10 years and 96.7% (94.5-98.9%) at 21 years. The 20-year stem survival for aseptic loosening was 100% with no cases of significant lysis found (lucent line > 2 mm) and no stems required revision. Patient demographics did not appear to influence risk of revision (p > 0.05). There were 2 revisions in total (2 for acetabular loosening with original stems retained). There were no PPFs identified at mean 21.5 year follow-up and 5 dislocations (5%).

CONCLUSIONS

The Lubinus SP II 170 mm stem demonstrated excellent survivorship and negligible PPF rates over 20 years following primary THA.

Examining the Relationship Between Value and Patient Satisfaction With Treatment in Total Joint Arthroplasty

Background

A shift toward performance, cost, outcomes, and patient satisfaction has occurred with healthcare reform promoting value-based programs. The purpose of this study was to evaluate the relationship between patient satisfaction and value with treatment in a cohort of patients undergoing total knee arthroplasty (TKA) and total hip arthroplasty (THA).

Methods

Value was determined by the relationship of treatment outcome with episodic cost. Measurements included both clinical outcomes and patient-reported outcomes. Participating surgeons took part in the modified Delphi method resulting in an algorithm measuring patient value. Treatment outcome, cost, and resultant value (outcome/cost) of both TKA and THA were evaluated using binomial logistic regression by adjusting for age, gender, body mass index, Charlson comorbidity index, tobacco, education, and income with patient-reported satisfaction as the outcome.

Results

This study had a total of 909 patients (TKA n = 438; THA n = 471), with an average age of 67 (TKA) and 65 (THA) years. Patient satisfaction shared a significant positive relationship with treatment outcome for TKA (odds ratio [OR] = 1.53, confidence interval [CI] = 1.35-1.73, P < .001) and THA (OR = 1.93, CI = 1.62-2.29, P < .001). Higher value was associated with a significantly higher odds of patient satisfaction for both TKA (OR = 1.39, CI = 1.25-1.54, P < .001) and THA (OR = 1.70, CI = 1.47-1.97, P < .001).

Conclusions

This study showed a positive relationship between treatment outcome but not cost with subsequent value and patient satisfaction. This method provides a promising approach to comprehensively evaluate outcomes, cost, and value of total joint arthroplasty procedures. This approach can help predict the probability of value-driven patient satisfaction.

Does Participation in Virtual or In-Person Preoperative Education Relate to Reduced Length of Stay After Total Joint Arthroplasty?

Background

Advancements in surgical procedures for total joint arthroplasty (TJA) have resulted in more effective procedures with more rapid recovery. To prepare patients for surgery, many organizations offer a preoperative "joint class," which has been associated with reduced length of stay (LOS). Virtual modes of education are increasingly favored for those having TJA.

Purpose

To determine whether participation in an individually administered preoperative educational session ("Prehab") relates to reduced LOS or increased likelihood of same-day discharge (SDD) for those undergoing TJA. Additionally, to establish whether and the virtual mode of education provision is superior or inferior to the in-person mode with regards to LOS benefits.

Methods

The author conducted a case-control study of 2532 patients who had a primary or revision TJA between January 2022 and August 2022 at a single institution. Data were obtained from the electronic medical record. A total of 1118 patients attended Prehab; 1414 patients did not. Patients were included if they were over the age of 18 and had a total hip arthroplasty (THA) or total knee arthroplasty (TKA) during the study period. T-tests, chi-square χ2 tests, and binomial logistic regression were used to evaluate the LOS and SDD outcomes for those who participated in Prehab compared with those who did not.

Results

Those receiving Prehab in any form had shorter LOS than those who had not. Those receiving virtual Prehab had the shortest LOS. There was no difference in the rate of SDD for outpatient-class patients.

Conclusion

Preoperative education is associated with LOS benefits to patients undergoing TJA. The virtual mode of education provision is at minimum non-inferior, and may be superior, to the in-person mode. The lack of statistically significant between-group differences for SDD outcomes may be explained by a lack of SDD-specific educational content provided during Prehab.

The five times sit-to-stand test predicts same-day discharge for outpatients undergoing total joint arthroplasty

PURPOSE

To examine whether a patient's pre-operatively administered five times sit-to-stand (FTSTS) test score, when used alone or when combined with previously established predictors, relates to same-day discharge (SDD) after total knee or hip arthroplasty.

METHODS

This study utilized a multivariate, retrospective, observational design. Electronic medical record data for included participants were used to analyze the relationship between the patient factors (including the novel FTSTS variable) and the SDD outcome. Univariate and multiple variable regression modeling was undertaken to understand the strength of the relationship between the independent variables with the dependent variable. Receiver operating curve (ROC) analysis was performed to determine the area under the curve (AUC) for the novel model. Cut score analysis was performed to establish the score which has the greatest utility for stratifying patients based upon their likelihood of achieving SDD.

RESULTS

All independent variables related to the SDD outcome with varying effect sizes. The dichotomized FTSTS score related to the SDD outcome with medium effect (Exp(B) = 2.56). The score of 13.6 s was established as the point where the test was most highly sensitive and specific. The combined model including all included patient characteristics had a classification accuracy of 64.7% and an area under the curve score of .724.

CONCLUSION

The FTSTS score had higher predictive accuracy than all other stand-alone patient characteristics for the SDD outcome.

Precision or Pitfall? Evaluating the Accuracy of ICD-10 Coding for Cemented Total Hip Arthroplasty: A Multicenter Study

BACKGROUND

The International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Procedure Coding System (ICD-10-PCS) was adopted in the U.S. in 2015. Proponents of the ICD-10-PCS have stated that its granularity allows for a more accurate representation of the types of procedures performed by including laterality, joint designation, and more detailed procedural data. However, other researchers have expressed concern that the increased number of codes adds further complexity that leads to inaccurate and inconsistent coding, rendering registry and research data based on ICD-10-PCS codes invalid and inaccurate. We aimed to determine the accuracy of the ICD-10-PCS for identifying cemented fixation in primary total hip arthroplasty (THA).

METHODS

We retrospectively reviewed all cemented primary THAs performed at 4 geographically diverse, academic medical centers between October 2015 and October 2020. Cemented fixation was identified from the ICD-10-PCS coding for each procedure. The accuracy of an ICD-10-PCS code relative to the surgical record was determined by postoperative radiograph and chart review, and cross-referencing with institution-level coding published by the American Joint Replacement Registry (AJRR) was also performed.

RESULTS

A total of 552 cemented THA cases were identified within the study period, of which 452 (81.9%) were correctly coded as cemented with the ICD-10-PCS. The proportion of cases that were correctly coded was 187 of 260 (72%) at Institution A, 158 of 185 (85%) at Institution B, 35 of 35 (100%) at Institution C, and 72 of 72 (100%) at Institution D. Of the 480 identified cemented THA cases at 3 of the 4 institutions, 403 (84%) were correctly reported as cemented to the AJRR (Institution A, 185 of 260 cases [71%]; Institution B, 185 of 185 [100%]; and Institution C, 33 of 35 [94%]). Lastly, of these 480 identified cemented THA cases, 317 (66%) were both correctly coded with the ICD-10-PCS and correctly reported as cemented to the AJRR.

CONCLUSIONS

Our findings revealed existing discrepancies within multiple institutional data sets, which may lead to inaccurate reporting by the AJRR and other registries that rely on ICD-10-PCS coding. Caution should be exercised when utilizing ICD-10 procedural data to evaluate specific details from administrative claims databases as these inaccuracies present inherent challenges to data validity and interpretation.

Experience of an Anatomic Femoral Stem in a United Kingdom Center - Excellent Survivorship and Negligible Periprosthetic Fracture Rates at Mean 12 Years Following Primary Total Hip Arthroplasty

BACKGROUND

As the clinical burden of periprosthetic fractures (PPFs) continues to increase, it has been suggested that the use of anatomical femoral stems may help reduce PPF risk. The primary aim of this study was to determine the survivorship and PPF rate of an anatomical femoral stem in a single center at minimum 10-year follow-up.

METHODS

A total of 1,000 consecutive total hip arthroplasties (THAs) performed using an anatomical femoral stem were identified from a prospectively collected arthroplasty database. Patient radiographs were reviewed finally at a mean of 12 years (range, 10 to 16 years) following surgery to identify any revision surgery, dislocations or PPFs. Mean patient age at surgery was 69 years (range, 24 to 93). There were 634 women (63%). Osteoarthritis was the operative indication in 946 patients (95%).

RESULTS

All-cause THA survivorship was 99.1% (95% confidence interval (CI), 99.0-99.3%) at 10 years and 97.9% (CI, 97.8 - 98.0%) at 15 years. Stem survivorship at 10 years was 99.6% (CI, 99.5-99.7%) and at 15 years was 98.2% (CI, 98.1-98.3%). The 15-year stem survival for aseptic loosening was 100% with no cases of significant lysis found (lucent line >2mm). Implant survivorship was not significantly impacted by patient sex (P = .65), body mass index (P = .49), deprivation level (P = .284), operative indication (P = .33), or American Society of Anesthesiologists class (P = .374). There were 3 PPFs identified (0.3%) at mean 12-year follow-up and 15 dislocations (1.5%).

CONCLUSION

This anatomical femoral stem demonstrated excellent survivorship and negligible PPF rates at mean 12-year follow-up following primary THA.

Total Hip Arthroplasty: An Update on Navigation, Robotics, and Contemporary Advancements

While total hip arthroplasty (THA) remains effective for improvement of pain and function in patients with osteoarthritis and avascular necrosis, there remain areas of continued pursuit of excellence, including decreasing rates of dislocation, leg length discrepancy, implant loosening, and infection. This review article covers several bearing surfaces and articulations, computer-assisted navigation and robotic technology, and minimally invasive surgical approaches that have sought to improve such outcomes. Perhaps the most significant improvement to THA implant longevity has been the broad adoption of highly cross-linked polyethylene, with low wear rates. Similarly, navigation and robotic technology has proven to more reproducibly achieve intraoperative component positioning, which has demonstrated clinical benefit with decreased risk of dislocation in a number of studies. Given the projected increase in THA over the coming decades, continued investigation of effective incorporation of technology, soft tissue-sparing approaches, and durable implants is imperative to continued pursuit of improved outcomes in THA.

Effect of duloxetine on opioid consumption and pain after total knee and hip arthroplasty: a systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

The purpose of this study was to investigate the analgesic effects of duloxetine, specifically on postoperative pain, opioid consumption, and related side effects following total hip or knee arthroplasty.

METHODS

In this systematic review and meta-analysis, Medline, Cochrane, EMBASE, Scopus, and Web of Science were searched until November 2022 for studies which compared duloxetine with placebo when added to routine pain management protocols. Individual study risk of bias assessment was conducted based on Cochrane risk of bias tool 2. Random effect model meta-analysis was done on mean differences, to evaluate the outcomes.

RESULTS

Nine randomized clinical trials (RCT) were included in the final analysis, totaling 806 patients. Duloxetine reduced opioid consumption (oral morphine milligram equivalents) on postoperative days (POD) 2 (mean difference (MD): -14.35, P  = .02), POD 3 (MD: -13.6, P < .001), POD 7 (MD: -7.81, P < .001), and POD 14 (MD: -12.72, P < .001). Duloxetine decreased pain with activity on POD 1, 3, 7, 14, 90 (All P < .05), and pain at rest on POD 2, 3, 7, 14, and 90 (all P < .05). There was no significant difference in the prevalence of the side effects, except for increased risk of somnolence/drowsiness (risk ratio: 1.87, P = .007).

CONCLUSION

Current evidence shows low to moderate opioid sparing effects of perioperative duloxetine and a statistically but not clinically significant reduction in pain scores. Patients treated with duloxetine had an increased risk for somnolence and drowsiness.

Oxidized Zirconium Versus Cobalt Chromium for Primary TKA: No Difference in Midterm Revision Rates From the American Joint Replacement Registry

BACKGROUND

Cobalt chromium (CoCr) is the most commonly used material in TKA; however, the use of oxidized zirconium (OxZr) implants has increased. The advantages to this material demonstrated in basic science studies have not been borne out in clinical studies to date.

QUESTION/PURPOSE

In the setting of the American Joint Replacement Registry (AJRR), how do revision rates differ between CoCr and OxZr after primary TKA?

METHODS

The AJRR was accessed for all primary TKAs performed between 2012 and 2020 for osteoarthritis, resulting in 441,605 procedures (68,506 with OxZr and 373,099 with CoCr). The AJRR is the largest joint replacement registry worldwide and collects procedure-specific details, making it ideal for large-scale comparisons of implant materials in the United States. Competing risk survival analyses were used to evaluate the all-cause revision rates of primary TKAs, comparing CoCr and OxZr implants. Data from the Centers for Medicare and Medicaid Services claims from 2012 to 2017 were also cross-referenced to capture additional revisions from other institutions. Revision rates were tabulated and subclassified by indication. Multivariate Cox regression was used to account for confounding variables such as age, gender, region, and hospital size.

RESULTS

After controlling for confounding variables, there were no differences between the OxZr and CoCr groups in terms of the rate of all-cause revision at a mean follow-up of 46 ± 23 months and 44 ± 24 months for CoCr and OxZr implants, respectively (hazard ratio 1.055 [95% confidence interval 0.979 to 1.137]; p = 0.16) The univariate analysis demonstrated increased rates of revisions for pain and instability in the OxZr group (p = 0.003 and p < 0.001, respectively).

CONCLUSION

These findings suggest there is no difference in all-cause revision between OxZr and CoCr implants in the short-term to mid-term. However, further long-term in vivo studies are needed to monitor the safety and all-cause revision rate of OxZr implants compared with those of CoCr implants. OxZr implants may be favorable in patients who have sensitivity to metal. Despite similar short-term to mid-term all-cause revision rates to CoCr implants, because of the limitations of this study, definitive recommendations for or against the use of OxZr cannot be made.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Preoperative Prediction and Risk Factor Identification of Hospital Length of Stay for Total Joint Arthroplasty Patients Using Machine Learning

Background

The aim of this study was to improve understanding of hospital length of stay (LOS) in patients undergoing total joint arthroplasty (TJA) in a high-efficiency, hospital-based pathway.

Methods

We retrospectively reviewed 1401 consecutive primary and revision TJA patients across 67 patient and preoperative care characteristics from 2016 to 2019 from the institutional electronic health records. A machine learning approach, testing multiple models, was used to assess predictors of LOS.

Results

The median LOS was 1 day; outpatients accounted for 16.5%, 1-day inpatient stays for 38.0%, 2-day stays for 26.4%, and 3-days or more for 19.1%. Patients characteristically fell into 1 of 3 broad categories that contained relatively similar characteristics: outpatient (0-day LOS), short stay (1- to 2-day LOS), and prolonged stay (3 days or greater). The random forest models suggested that a lower Risk Assessment and Prediction Tool score, unplanned admission or hospital transfer, and a medical history of cardiovascular disease were associated with an increased LOS. Documented narcotic use for surgery preparation prior to hospitalization and preoperative corticosteroid use were factors independently associated with a decreased LOS.

Conclusions

After TJA, most patients have either an outpatient or short-stay hospital episode. Patients who stay 2 days do not differ substantially from patients who stay 1 day, while there is a distinct group that requires prolonged admission. Our machine learning models support a better understanding of the patient factors associated with different hospital LOS categories for TJA, demonstrating the potential for improved health policy decisions and risk stratification for centers caring for complex patients.

The Role of Platelet-Rich Plasma Therapy in Joint Arthroplasty A Mini-Review

Orthobiologics are playing an increasingly large role in the clinical setting across multiple fields of surgery. Particularly, in the field of orthopedic surgery, the employment of platelet-rich plasma (PRP) therapy in total joint arthroscopy (TJA) has become popular for its prompted benefits of controlling pain, blood loss, and increased wound healing. PRP was originally used for thrombolytic conditions, however, the aforementioned potential benefits have led to its increased use across various fields of medicine including dermatology, neurosurgery, orthopedics, and sports medicine. Currently, there is a persisting gap in the literature surrounding the mechanism of action of PRP, as well as its true role in increasing positive patient outcomes in the context of TJA. Thus, this review aims to briefly highlight the physiological mechanisms underlining PRP therapy, evaluate recent preclinical and clinical data about its effects on TJA patient outcomes, and to describe its concomitant use in novel orthopedic-applications.

Automatic Detection of Two Synovial Fluid Periprosthetic Joint Infection Biomarkers on an Integrated Microfluidic System

Post-arthroplasty periprosthetic joint infection (PJI) is a serious ailment that can be difficult to diagnose. Herein, we developed a novel integrated microfluidic system (IMS) capable of detecting two common PJI biomarkers, alpha defensin human neutrophil peptide 1 (HNP-1) and C-reactive protein (CRP), from synovial fluid (SF). A magnetic bead-based one-aptamer-one-antibody assay was carried out automatically within 45 min on a single chip for simultaneous detection of both biomarkers at concentration ranges of 0.01-50 (HNP-1) and 1-100 (CRP) mg/L. It is the first report for utilizing these two biomarkers as targets to establish the new one-aptamer-one-antibody assay to detect PJI on-chip, and the aptamers demonstrated high specificity to their SF targets. As 20 clinical samples were correctly diagnosed with our IMS (verified by a common gold standard kit), it could serve as a promising tool for PJI diagnostics.

Total Joint Arthroplasty Patient Demographics Before and After Coronavirus Disease 2019 Elective Surgery Restrictions

Background

In 2020, the coronavirus disease 2019 (COVID-19) pandemic caused the cessation of nonemergent total joint arthroplasty (TJA, referring to total hip and total knee arthroplasty) operations between mid-March and April 2020. The purpose of this study is to analyze the effects and potential disparities in access to care due to the COVID-19 restrictions.

Methods

A database was used to examine the demographics of patients undergoing TJA from May to December 2019 (pre-COVID-19) and from May to December 2020 (post-COVID-19 restrictions). Categorical covariates were summarized by reporting counts and percentages and compared using Fisher exact tests. Continuous covariates were summarized by reporting means and standard deviations. Two-sample t-tests were used for continuous covariates. The equality of TJA counts by year was tested using a test of proportions.

Results

There were more TJA procedures performed during the post-COVID-19 period in 2020 than in the pre-COVID-19 period (1151 vs 882, P < .001). There was an increase in the relative percentage of THAs vs TKAs performed in 2020 vs 2019 (26.9% vs 18.8%, P < .001) and an increase in patients with Medicaid with a decrease in private insurance (P = .043). The average length of stay was shorter in 2020 with a greater percentage of TJAs performed outpatient (P < .001). There were no differences in patient sex, race, body mass index, smoking status, or age between the 2 periods.

Conclusions

A relative increase in THA procedures, an increase in patients with Medicaid and decrease in private insurance, and a a decreased length of stay were seen after COVID-19 restrictions. These trends may reflect pandemic-related changes in insurance status as well as the growing shift to same-day discharge.

Dual-analgesic loaded UHMWPE exhibits synergistic antibacterial effects against Staphylococci

Total joint arthroplasty is one of the most common surgeries in the United States, with almost a million procedures performed annually. Periprosthetic joint infections (PJI) remain the most devastating complications associated with total joint replacement. Effective antibacterial prophylaxis after primary arthroplasty could substantially reduce incidence rate of PJI. In the present study we propose to provide post-arthroplasty prophylaxis via dual-analgesic loaded ultra-high molecular weight polyethylene (UHMWPE). Our approach is based on previous studies that showed pronounced antibacterial activity of analgesic- and NSAID-loaded UHMWPE against Staphylococci. Here, we prepared bupivacaine/tolfenamic acid-loaded UHMWPE and assessed its antibacterial activity against Staphylococcus aureus and Staphylococcus epidermidis. Dual-drug loaded UHMWPE yielded an additional 1-2 log reduction of bacteria, when compared with single-drug loaded UHMWPE. Analysis of the drug elution kinetics suggested that the observed increase in antibacterial activity is due to the increased tolfenamic acid elution from dual-drug loaded UHMWPE. We showed that the increased fractal dimension of the drug domains in UHMWPE could be associated with increased drug elution, leading to higher antibacterial activity. Dual-analgesic loaded UHMWPE proposed here can be used as part of multi-modal antibacterial prophylaxis and promises substantial reduction in post-arthroplasty mortality and morbidity.

Knee Injury and Osteoarthritis Outcome Score Trajectories After Primary Total Knee Arthroplasty in United States Veterans

INTRODUCTION

The volume of total knee arthroplasty (TKA) procedures continues to increase, including among United States (US) veterans, but there is little data characterizing recovery using validated knee-related questionnaires.

METHODS

In this prospective cohort study, we sought to establish the feasibility of longitudinal characterization of recovery after TKA using the validated Knee Injury and Osteoarthritis Outcome Score (KOOS), specifically focusing on two of the KOOS subscales (pain and quality of life (QOL)). We solicited participants who agreed to fill out these knee-related questionnaires preoperatively and 3, 6, and 12 months after discharge following unilateral TKA within the Durham Veterans Affairs Health Care System. We examined rates of prospective completion of the KOOS and face validity of scores at each study time point. We transformed and reported scores on the 0-100 scale, with zero representing significant knee pain or poor QOL and 100 representing no knee pain or good QOL.

RESULTS

Of 200 US veterans presenting between May 2017 and 2018, 21 (10.5%) agreed to participate by filling out the KOOS questionnaire longitudinally from before surgery until one year after discharge. All 21 (100%) participants were male and completed the two KOOS subscale questions (pain and QOL) preoperatively. Of those, 16 (76.2%) also completed KOOS at 3 months, 16 (76.2%) at 6 months, and seven (33.3%) at 12 months. Compared to mean preoperative values (pain: 33.47 + 6.78, QOL: 11.91 + 4.99), the KOOS subscale scores had significantly improved by 6 months after TKA (pain: 74.41 + 10.72, QOL: 49.61 + 13.25) but plateaued at 12 months (pain: 74.60 + 20.80, QOL: 50.89 + 20.61). The magnitude of improvement in absolute scores, pain and QOL, was similar and significant at 12 months compared to preoperative values with an increase of 41.13 (p=0.007) and 38.98 (p=0.009), respectively.

CONCLUSION

Primary TKA in US veterans with advanced osteoarthritis may lead to improved patient-reported KOOS pain and QOL subscale measures at 12 months compared to preoperative scores, with the majority of improvement occurring by 6 months. Only one in ten US veterans approached preoperatively agreed to complete the validated knee-related outcomes questionnaire prior to undergoing TKA. About three-quarters of those veterans also completed it both three and six months after discharge. Collected KOOS subscale scores demonstrated face validity and showed substantial improvement in pain and QOL over the six-month postoperative period. Only one in three veterans who completed the KOOS questionnaire preoperatively also completed it at 12 months, but this does not support the feasibility of follow-up assessments beyond 6 months. To better understand longitudinal pain and QOL trajectories in US veterans undergoing primary TKA for advanced osteoarthritis and to improve study participation, additional research using the KOOS questionnaire may add further insights into this underreported population.

Do patient-reported outcome measures improve after aseptic revision total hip arthroplasty?

BACKGROUND

The purpose of this study was to determine patient-reported outcome measures (PROMs) changes in: (1) pain, function and global health; and (2) predictors of PROMs in patients undergoing aseptic revision total hip arthroplasty (rTHA) using a multilevel model with patients nested within surgeon.

METHODS

A prospective cohort of 216 patients with baseline and 1-year PROMs who underwent aseptic rTHA between January 2016 and December 2017 were analysed. The most common indication for rTHA was aseptic loosening, instability, and implant failure. The PROMs included in this study were HOOS Pain and HOOS Physical Function Short-form (PS), Veterans RAND-12 Physical Component Score (VR-12 PCS), and VR-12 Mental Component Score (MCS). Multivariable linear regression models were constructed for predicting 1-year PROMs.

RESULTS

Mean 1-year PROMs improvement for aseptic revisions were 30.4 points for HOOS Pain and 22.1 points for HOOS PS. Predictors of better pain relief were patients with higher baseline pain scores. Predictors of better 1-year function were patients with higher baseline function and patients with a posterolateral hip surgical approach during revision. Although VR-12 PCS scores had an overall improvement, nearly 50% of patients saw no improvement or had worse physical component scores. Only 30.7% of patients reported improvements in VR-12 MCS.

CONCLUSIONS

Overall, patients undergoing aseptic rTHA improved in pain and function PROMs at 1 year. Although global health assessment improved overall, nearly half of aseptic rTHA patients reported no change in physical/mental health status. The associations highlighted in this study can help guide the shared decision-making process by setting expectations before aseptic revision THA.

Cartilage-inspired surface textures for improved tribological performance of orthopedic implants

Joint replacements have become one of the most common orthopedic procedures due to the significant demands of retaining functional mobility. While these procedures are of great value to patients, there are some limitations. Durability is the most important limitation associated with joint replacement that needs to be addressed due to the increasing number of younger patients. Titanium is a commonly used implant material which has high biocompatibility, high strength-to-density ratio, and high corrosion resistance. However, current titanium implants have poor wear resistance which shortens their lifespan. In this study, microscale dimples with four different dimple shapes (circular, triangular, square, and star) of similar sizes to the pores found in natural articular cartilage were fabricated on titanium disks to improve implant lubrication and reduce wear. Biotribology tests were performed on dimpled and non-dimpled titanium disks in a condition similar to that inside of a patient's body. It was shown that dimpling the titanium disks optimized the lubricant film formation and decreased the wear rate significantly while also reducing the coefficient of friction (COF). The star-shaped dimples had the lowest COF and almost no detectable wear after 8 h of testing. To investigate whether dimpling increased bacterial colonization due to increased surface area, and to determine whether any increase could be limited by coating with antibacterial materials, bacterial colonization with Staphylococcus aureus was tested with non-dimpled and star-shaped dimpled titanium disks with and without coating with polydopamine (PDA), silver (Ag) nanoparticles (NPs), and PDA + Ag NPs. It was found that dimpling did not increase bacterial colonization, and that coating with PDA, Ag NPs, or PDA + Ag NPs did not decrease bacterial colonization. Nevertheless, we conclude that star-shaped dimpled titanium surfaces have potential utility as more durable orthopedic implants.

Discharge to inpatient rehabilitation following arthroplasty is a strong predictor of persistent opioid use 90 days after surgery: a prospective, observational study

BACKGROUND

Total knee and hip arthroplasty are considered a clinically and cost-effective intervention, however, persistent pain post-surgery can occur, and some continue to take opioid medications long-term. One factor which has infrequently been included in prediction modelling is rehabilitation pathway, in particular, one which includes inpatient rehabilitation. As discharge to inpatient rehabilitation post-arthroplasty is common practice, we aimed to identify whether rehabilitation pathway (discharge to in-patient rehabilitation or not) predicts continued use of opioids at 3 months (90 days) post- total knee arthroplasty (TKA) and total hip arthroplasty (THA) whilst controlling for other covariates.

METHODS

The study was nested within a prospective observational study capturing pre-operative, acute care and longer-term data from 1900 osteoarthritis (OA) patients who underwent primary TKA or THA. The larger study involved a part-random, part-convenience sample of 19 high-volume hospitals across Australia. Records with complete pre-and post-operative analgesic (35 days and 90 days) use were identified [1771 records (93% of sample)] and included in logistic regression analyses.

RESULTS

Three hundred and thirteen people (17.8%) reported ongoing opioid use at 90 days post-operatively. In the adjusted model, admission to inpatient rehabilitation after surgery was identified as an independent and significant predictor of opioid use at 90-days. Inpatient rehabilitation was associated with almost twice the odds of persistent opioid use at 90-days compared to discharge directly home (OR = 1.9 (1.4, 2.5), p < .001).

CONCLUSION

The inpatient rehabilitation pathway is a strong predictor of longer-term opioid use (90 days) post-arthroplasty, accounting for many known and possible confounders of use including sex, age, insurance status, major complications, smoking status and baseline body pain levels.

TRIAL REGISTRATION

The study was nested within a prospective cohort observational study capturing pre-operative, acute-care and longer-term data from patients undergoing primary TKA or THA for osteoarthritis (ClinicalTrials.gov NCT01899443).

The Timing of Preoperative Urinary Tract Infection Influences the Risk of Prosthetic Joint Infection Following Primary Total Hip and Knee Arthroplasty

BACKGROUND

The importance of preoperative urinary tract infection (UTI) in total hip and knee arthroplasty (THA and TKA) is controversial. The purpose of this study was to investigate the timing of preoperative UTI diagnosis and association with prosthetic joint infection (PJI) and determine if antibiotics impact this risk.

METHODS

A national database was used to analyze patients undergoing THA and TKA diagnosed with a preoperative UTI. Timing of diagnosis was categorized by 1-week intervals prior to surgery. Matched cohorts without UTI were collected, and PJI rates within 2 years of surgery were compared. Patients who received antibiotic prescriptions were identified and compared to no prescription.

RESULTS

Preoperative UTI within 1 week of TKA was associated with higher rates of PJI (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.26-1.43, P < .001). Preoperative UTI within 1 week of THA (OR 1.56, 95% CI 1.44-1.68, P < .001) and between 1-2 weeks prior to THA (OR 1.12, 95% CI 1.02-1.22, P = .022) was associated with significantly higher rates of PJI. UTI diagnosis at any other time interval did not reach statistical significance. Antibiotic prescription was not associated with lower rates of PJI.

CONCLUSION

Patients with preoperative UTI within 1 week of TKA or within 2 weeks of THA have an increased risk of postoperative PJI. Antibiotics do not appear to mitigate risk.

LEVEL OF EVIDENCE

Level III; Retrospective, database comparison.

Effect of Weight Change on Patient-Reported Outcomes Following Total Joint Arthroplasty

BACKGROUND

Increased body mass index (BMI) has been previously described as a risk factor for complications after total joint arthroplasty (TJA); however, its effect on patient-reported outcomes has not been thoroughly investigated. This study examines the effect of postoperative weight change on the Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF) scores for total knee arthroplasty (TKA) and total hip arthroplasty (THA) patients.

METHODS

A retrospective review of 988 patients undergoing THA or TKA was performed. PROMIS-PF scores and BMI were recorded throughout the study duration. Patients were classified by a 5% change in BMI. A univariate analysis evaluated differences across groups. Mixed-effect models evaluated predictors of change in functional score over the postoperative follow-up time.

RESULTS

43.1% patients had a THA and 56.9% patients had a TKA. At 0 to 3 months, 92% of patients had no change in BMI, 3 to 6 months 82% had no change, and 6 to 12 months 80% had no change. There were no significant demographic or comorbidity differences across groups for both THA and TKA. Similar improvements in PROMIS-PF scores were observed across weight change groups. In the mixed-effect models, postoperative time was found to be a significant predictor of postoperative PF score. Both THA and TKA patients saw greater improvements in PROMIS-PF scores in patients with lower preoperative BMIs.

CONCLUSION

These results demonstrate most patients do not experience substantial changes in weight following TJA. However, lower BMIs at the time of surgery were associated with an increased functional improvement. Therefore, efforts to optimize BMI should be focused preoperatively to improve surgical outcomes.

Early Results of Bone-Conserving High Flexion Posterior-Stabilized Total Knee System in Indian Population

Background

A number of total knee arthroplasty (TKA) systems are used across a variety of markets in which outcome will be influenced by patient factors, surgical technique and implant characteristics. The aim of the current study was to report the early functional results of a primary TKA system in support of the component design characteristics adapted for achieving increased functional expectations of the patients.

Materials and Methods

A prospective, continuous series of 304 primary posterior-stabilized (PS) TKAs were performed in 208 patients by a single surgeon. Inclusion criterion was patients undergoing primary TKA with Freedom Total Knee system and willing to participate in the study. Exclusion criteria were patients undergoing revision TKA, patients not willing to participate and patients who were lost to follow-up. Patients were clinically and radiologically assessed for a minimum of 5 years post-operatively. Oxford Knee score (OKS) and range of motion (ROM) were assessed for the entire study population and by gender.

Results

There were no patients who were lost to follow-up. Two patients (Two knees) required incision and secondary suturing for superficial skin wound complication. At minimum 5-year follow-up, there was no radiographic evidence of component loosening/failure. Clinical evaluation at 5 years post-operatively showed statistically significant increase in the OKS and ROM as compared to pre-operative values (OKS pre-operative 19.27 ± 1.86, post-operative 38.76 ± 1.5, p value < 0.001, ROM pre-operative 94.57 ± 3.49, post-operative 127.69 ± 3.65, p value < 0.001). There was no statistically significant difference in the clinical outcome between male and female genders as well as between unilateral and bilateral TKA.

Conclusion

The study showed encouraging early results for the bone-conserving high flexion TKA system in 208 patients at minimum 5-year follow-up. The adapted design characteristics for improved functional expectations are confirmed in this reported Indian population study group cohort. Further continued evaluation is warranted for this primary TKA system across Indian and other ethnic population.

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

Microbial resistance to current antibiotics therapies is a major cause of implant failure and adverse clinical outcomes in orthopaedic surgery. Recent developments in advanced antimicrobial nanotechnologies provide numerous opportunities to effective remove resistant bacteria and prevent resistance from occurring through unique mechanisms. With tunable physicochemical properties, nanomaterials can be designed to be bactericidal, antifouling, immunomodulating, and capable of delivering antibacterial compounds to the infection region with spatiotemporal accuracy. Despite its substantial advancement, an important, but under-explored area, is potential microbial resistance to nanomaterials and how this can impact the clinical use of antimicrobial nanotechnologies. This review aims to provide a better understanding of nanomaterial-associated microbial resistance to accelerate bench-to-bedside translations of emerging nanotechnologies for effective control of implant associated infections.

Cellular responses to nanoscale substrate topography of TiO2 nanotube arrays: cell morphology and adhesion

Nanotopographical features can be beneficial in augmenting cell functions and increasing osteogenic potential. However, the relationships between surface topographies and biological responses are difficult to establish due to the difficulty in controlling the surface topographical features at a low-nanometre scale. Herein, we report the fabrication of well-defined controllable titanium dioxide (TiO₂) nanotube arrays with a wide range of pore sizes, 30-175 nm in diameter, and use of the electrochemical anodization method to assess the effect of surface nanotopographies on cell morphology and adhesion. The results show that TiO₂ nanotube arrays with pore sizes of 30 and 80 nm allowed for cell spreading of bone marrow-derived mesenchymal stem cells with increased cell area coverage. Additionally, cell adhesion was significantly enhanced by controlled nanotopographies of TiO₂ nanotube arrays with 80 nm pore size. Our results demonstrate that surface modification at the nano-scale level with size tunability under controlled chemical/physical properties and culture conditions can greatly impact cell responses. These findings point to a new direction of material design for bone-tissue engineering in orthopaedic applications.

Outpatient total knee and hip arthroplasty present comparable and even better clinical outcomes than inpatient operation

Background

The purpose of this study was to compare total complications, complications stratified by type, readmissions, and reoperations at 30 and 90 days after outpatient and standard inpatient total knee and total hip arthroplasty (TKA, THA).

Methods

A literature search was conducted from the PubMed, Cochrane Library, and Embase databases for articles published before 20 August 2021. The types of studies included prospective randomized controlled trials, prospective cohort studies, retrospective comparative studies, retrospective reviews of THA and TKA registration databases, and observational case-control studies. Comparisons of interest included total complications, complications stratified by type, readmissions, and reoperations at 30 and 90 days. The statistical analysis was performed using Review Manager 5.3.

Results

Twenty studies with 582,790 cases compared relevant postoperative indicators of outpatient and inpatient total joint arthroplasty (TJA) (TKA and THA). There was a significant difference in the total complications at 30 days between outpatient and inpatient THA (p = 0.001), readmissions following TJA (p = 0.03), readmissions following THA (p = 0.001), stroke/cerebrovascular incidents following TJA (p = 0.01), cardiac arrest following TJA (p = 0.007), and blood transfusions following TJA (p = 0.003). The outcomes showed an obvious difference in 90-day total complications between outpatient and inpatient TJA (p = 0.01), readmissions following THA (p = 0.002), and surgical-related pain following TJA (p < 0.001). We did not find significant differences in the remaining parameters.

Conclusion

Outpatient procedures showed comparable and even better outcomes in total complications, complications stratified by type, readmissions, and reoperations at 30 and 90 days compared with inpatient TJA for selected patients.

Patient perspectives of pain and function after knee replacement: a systematic review and meta-synthesis of qualitative studies

Introduction

Joint replacement surgery typically results in good clinical outcome, although some people experience suboptimal pain relief and functional improvement. Predicting surgical outcome is difficult.

Objectives

There is merit in better understanding patients' perspectives of pain and function to identify avoidable problems perceived to contribute to their outcome, to inform prognostic expectations, and to identify potential cointerventions to sit alongside surgery that might mitigate pain/functional problems. Here, we aimed to synthesise the available literature exploring perspectives of people with knee osteoarthritis about their pain and function following joint replacement.

Methods

Six electronic databases and 2 websites were searched. Two independent reviewers completed study inclusion, quality assessment, and data extraction. Data were iteratively synthesised using first-, second-, and third-order analyses.

Results

Twenty-eight studies were included. Four themes were identified; perceptions of pain and function were inseparable. Theme 1 addressed experiences of recovery after surgery, which often differed from expectations. Theme 2 described the challenges of the pain experience and its functional impact, including the difficulty navigating medication use in context of personal beliefs and perceived stigma. Theme 3 articulated the toll of ongoing problems spanning pain-function-mood, necessitating the need to "endure." Theme 4 encompassed the importance of clinical/social interactions on mood and pain, with reports of concerns dismissed and practical support missing.

Conclusions

Together, these findings show that numerous individual considerations beyond the technical aspects of surgery influence experiences of pain and function. A tailored approach addressing these considerations from the patient perspective could provide a basis for improved success of knee replacement surgery.

Fabrication and Characterization of Bioactive Gelatin-Alginate-Bioactive Glass Composite Coatings on Porous Titanium Substrates

In this research work, the fabrication of biphasic composite implants has been investigated. Porous, commercially available pure Ti (50 vol % porosity and pore distributions of 100-200, 250-355, and 355-500 μm) has been used as a cortical bone replacement, while different composites based on a polymer blend (gelatin and alginate) and bioactive glass (BG) 45S5 have been applied as a soft layer for cartilage tissues. The microstructure, degradation rates, biofunctionality, and wear behavior of the different composites were analyzed to find the best possible coating. Experiments demonstrated the best micromechanical balance for the substrate containing 200-355 μm size range distribution. In addition, although the coating prepared from alginate presented a lower mass loss, the composite containing 50% alginate and 50% gelatin showed a higher elastic recovery, which entails that this type of coating could replicate the functions of the soft tissue in areas of the joints. Therefore, results revealed that the combinations of porous commercially pure Ti and composites prepared from alginate/gelatin/45S5 BG are candidates for the fabrication of biphasic implants not only for the treatment of osteochondral defects but also potentially for any other diseases affecting simultaneously hard and soft tissues.

Which Factors Predict 30-Day Readmission After Total Hip and Knee Replacement Surgery?

Background

The Centers for Medicare and Medicaid Services enacted the Hospital Readmissions Reduction Program to impose penalties for diagnoses with high readmission rates. Despite several elective orthopedic procedures being included in this program, readmission rates have not declined, and associated costs have reached critical levels for total knee and total hip arthroplasty. Readmissions drastically impact patient outcomes. There are many known contributors to patient readmission rates, including infection, pain, and hematomas. However, evidence is inconclusive regarding other aspects, such as demographics, insurance, and discharge disposition. The purpose of this manuscript is to 1) measure hospital readmission rates for total knee and total hip arthroplasty, 2) evaluate the causes of readmissions, and 3) provide a predictive profile of risk factors associated with hospital readmissions.

Methods

Patients who underwent total knee or total hip arthroplasty were identified through a retrospective database review. An electronic chart review extracted data concerning patient demographics, comorbidities, surgical information, 30-day outcomes, and reasons for 30-day readmissions. Continuous and categorical variables were assessed with the Wilcoxon rank-sum test and the Chi-square test, respectively.

Results

A total of 6,065 patients were included, with 269 (4.4%) having at least one surgery-related 30-day readmission. No differences in readmission were noted with age, sex, or ethnicity; however, differences were found in weight and body mass index. Statistically significant comorbidities were heart failure, chronic obstructive pulmonary disease, dialysis, and alcohol use or abuse.

Conclusion

Our research indicated that surgery type, length of stay, and heart failure most significantly impacted 30-day readmission rates. By assessing readmission rates, we can take steps to optimize care for non-elective surgeries that will improve patient outcomes and cost-effectiveness.

Variation in the Profit Margin for Different Types of Total Joint Arthroplasty

BACKGROUND

As health care shifts to a value-based model with bundled-payment methods, it is important to understand the costs and reimbursements of arthroplasty procedures that represent the largest expenditure of Medicare. The aim of the present study was to characterize the variation in (1) total hospital costs, (2) reimbursement, and (3) profit margin for different arthroplasty procedures.

METHODS

The total hospital costs of total knee arthroplasty (TKA), total hip arthroplasty (THA), anatomic total shoulder arthroplasty (TSA), reverse shoulder arthroplasty (RSA), and total ankle arthroplasty (TAA) were calculated with use of time-driven activity-based costing at an orthopaedic institution from 2018 to 2020. The average reimbursement for each type of procedure was determined. Profit margin, defined as the reimbursement profit after direct costs, was calculated by deducting the average time-drive activity-based total hospital costs from the reimbursement value. Multivariate analyses were performed to evaluate the associations between costs, reimbursement, and profit margins.

RESULTS

There were 13,545 arthroplasty procedures analyzed for this study, including 6,636 TKAs, 5,902 THAs, 346 TSAs, 577 RSAs, and 84 TAAs. Costs and reimbursement were highest for TAA. THA and TKA resulted in the highest profit margins, whereas RSA resulted in the lowest. The strongest associations with profit margin were private insurance (0.46547), age (-0.22732), and implant cost (-0.19240).

CONCLUSIONS

THA and TKA had greater profit margins overall than TAA and upper-extremity arthroplasty in general. Profit margins for RSA, TSA, and TAA were all at least 28% lower than those for TKA or THA. Lower-volume arthroplasty procedures were associated with decreased profit margins. Study findings suggest that optimizing implant costs and length of stay are important for sustaining institutional fiscal health when performing shoulder and ankle arthroplasty surgery.

Opioid-Prescribing Practices Between Total Knee and Hip Arthroplasty in an Outpatient Versus Inpatient Setting

ABSTRACT

Despite trends showing increases in the utilization of outpatient (OP) ambulatory surgery centers (ASCs) and decreases in the utilization of inpatient (IP) facilities for total knee arthroplasty (TKA) and total hip arthroplasty (THA), little is known about opioid prescribing for these procedures between each setting. This study evaluated differences in opioid prescribing and consumption between OP ASC and IP settings for elective TKA and THA surgeries over a 1-year period. Data collection also included pain and satisfaction of pain control postsurgery. In an OP ASC, analysis revealed a significant decrease in pills prescribed (p < .001, p < .001) and consumed (p < .001, p < .001) for TKA and THA, respectively. There was a significant decrease in the morphine equivalence units prescribed (p < .001, p < .001) and consumed (p < .001, p < .001) for TKA and THA, respectively. For TKA, pain was significantly lower (p = .018) and satisfaction of pain control was significantly higher (p = .007). For THA, pain (p = .374) and satisfaction of pain control (p = .173) were similar between the settings. Benefits of performing these surgeries in an OP ASC setting are patients having similar or lower levels of pain and having similar or higher satisfaction of pain control. Patients are also prescribed and consume less opioids. This has important implications for healthcare systems.

Comparing Postoperative Readmission Rates Between Veterans Receiving Total Knee Arthroplasty in the Veterans Health Administration Versus Community Care

BACKGROUND

There are growing concerns that Veterans' increased use of Veterans Health Administration (VA)-purchased care in the community may lead to lower quality of care.

OBJECTIVE

We compared rates of hospital readmissions following elective total knee arthroplasties (TKAs) that were either performed in VA or purchased by VA through community care (CC) at both the national and facility levels.

METHODS

Three-year cohort study using VA and CC administrative data from the VA's Corporate Data Warehouse (October 1, 2016-September 30, 2019). We obtained Medicare data to capture readmissions that were paid by Medicare. We used the Centers for Medicare and Medicaid Services (CMS) methods to identify unplanned, 30-day, all-cause readmissions. A secondary outcome, TKA-related readmissions, identified readmissions resulting from complications of the index surgery. We ran mixed-effects logistic regression models to compare the risk-adjusted odds of all-cause and TKA-related readmissions between TKAs performed in VA versus CC, adjusting for patients' sociodemographic and clinical characteristics.

PRINCIPAL FINDINGS

Nationally, the odds of experiencing an all-cause or TKA-related readmission were significantly lower for TKAs performed in VA versus CC (eg, the odds of experiencing an all-cause readmission in VA were 35% of those in CC. At the facility level, most VA facilities performed similarly to their corresponding CC providers, although there were 3 VA facilities that performed worse than their corresponding CC providers.

CONCLUSIONS

Given VA's history in providing high-quality surgical care to Veterans, it is important to closely monitor and track whether the shift to CC for surgical care will impact quality in both settings over time.

Aptamer selection against alpha-defensin human neutrophil peptide 1 on an integrated microfluidic system for diagnosis of periprosthetic joint infections

Periprosthetic joint infections (PJIs) arising from joint arthroplasty are dreadful, yet difficult to diagnose in subtle cases. Definite diagnosis requires microbiological culture to confirm the causative pathogens. However, up to 40% of culture-negative PJI needs other surrogate biomarkers such as human neutrophil peptide 1 (HNP 1) to improve diagnostic accuracy or gauge therapeutic responses. To devise a diagnostic method, systematic evolution of ligands by exponential enrichment (SELEX) (five rounds) was used to screen PJI biomarkers on a compact (20 × 20 × 35 cm), integrated microfluidic system equipped with two separate Peltier devices and one magnetic control module where an aptamer with high affinity and specificity for HNP 1, which has been used as one of the synovial fluid (SF) biomarkers for detecting PJI, was identified for the first time. Two rounds of negative selection (with immunoglobulin G & human serum album) on-chip followed by one round of unique "competitive selection" with SF extracted from PJI patients validated the specificity of the HNP 1 aptamer. The dissociation constant was measured to be 19 nM. The applicability of SF HNP 1 levels for diagnosing PJI was then verified by a new aptamer-based enzyme-linked immunosorbent assay (ELISA)-like assay. It is envisioned that this new aptamer and the associated assay could be used in future clinical applications.

Management of prosthetic joint infections: a guidelines comparison

BACKGROUND

In the last decade, the number of prosthetic joint replacements has been rising each year and this growing trend is related to the increased number of prosthetic joint infections (PJI). As PJI represent a devastating condition for the patient, physicians must identify the best treatment option for each case. Guidelines are not always clear regarding the most appropriate therapy pathway as they differ in many parameters.

MATERIALS AND METHODS

Aim of this article is to compare the different indications as reported by four major Academic Societies: the Infectious Disease Society of America, the American Academy of Orthopaedic Surgeons, and the Musculoskeletal Infection Society (MSIS) which published the guideline in partnership with the European Bone And Joint Infection Society.

CONCLUSIONS

PJI Guidelines differ in many parameters, therefore the choice of treatment for each case does not appear immediate; it would be desirable that, in the next few years, new scientific evidence will help clarify the indications of the most effective therapeutic protocols for PJI to determine the ultimate surgical strategy for every single patient.

No Additional Benefits of Tissue Adhesives for Skin Closure in Total Joint Arthroplasty: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

This systematic review is aimed to compare the performance of tissue adhesives (TA) as an adjunct or closure method with traditional wound closure methods for cutaneous closure in arthroplasty and evaluate whether they have any added benefits in terms of decreasing wound complications and increasing postoperative patient satisfaction.

METHODS

Cochrane Library, PubMed, and EMBASE were searched until February 2021. Randomized controlled trials (RCTs) comparing outcomes of TA with emphasis on skin closure time, in-hospital stay, complication rates, cosmetic scoring systems, and patient satisfaction scores (PSS) compared to subcuticular sutures (SCS) and skin staples (ST) in arthroplasty. The quality of RCTs was assessed using the National Institutes of Health quality assessment tool.

RESULTS

Ten RCTs were included. The pooled and the subgroup analysis revealed no significant difference in the wound infection rates, discharge rates, dehiscence rates, and PSS between TA (as an adjunct or closure method) and SCS or ST. TA (as an adjunct or closure method) was significantly (P < .00001) associated with a longer time to closure compared to ST and a shorter time compared to SCS as a closure method. Length of stay was comparable in all groups.

CONCLUSION

Using TA in combination with subcuticular sutures or ST or as a cutaneous method of closure does not provide additional benefits in terms of decreased hospital stay, decreased infection rates, or wound discharge rates. The PSS and pain scores of the scars also appear to be comparable to standard wound closure methods. No clear conclusion could be drawn regarding cosmetic scoring systems, because of the paucity of data.

LEVEL OF EVIDENCE

Level I (Meta-analysis of RCTs).

The Olympia anatomic polished cemented stem is associated with a high survivorship, excellent hip-specific functional outcome, and high satisfaction levels: follow-up of 239 consecutive patients beyond 15 years

INTRODUCTION

The Olympia femoral stem is a stainless steel, anatomically shaped, polished and three-dimensionally tapered implant designed for use in cemented total hip arthroplasty (THA). The primary aim of this study was to determine the long-term survivorship, radiographic outcome, and patient-reported outcome measures (PROMs) of the Olympia stem.

PATIENTS AND METHODS

Between May 2003 and December 2005, 239 patients (264 THAs) underwent a THA with an Olympia stem in our institution. Patient-reported outcome measures were assessed using the Oxford Hip Score (OHS), EuroQol-5 dimensions (EQ-5D) score, and patient satisfaction at mean 10 years following THA. Patient records and radiographs were then reviewed at a mean of 16.5 years (SD 0.7, 15.3-17.8) following THA to identify occurrence of complications or revision surgery for any cause following surgery. Radiographs were assessed for lucent lines and lysis according to Gruen's zones RESULTS: Mean patient age at surgery was 68.0 years (SD 10.9, 31-93 years). There were 156 women (65%, 176 THAs). Osteoarthritis was the indication for THA in 204 patients (85%). All cause stem survivorship at 10 years was 99.2% (95% confidence interval [CI], 97.9%-100%) and at 15 years was 97.5% (94.6%-100%). The 15-year stem survival for aseptic loosening was 100%. Analysis of all-cause THA failure demonstrated a survivorship of 98.5% (96.3%-100%) at 10 years and 95.9% (92.4%-99.4%) at 15 years. There were 9 THAs with non-progressive lucent lines in a single Gruen zone and 3 had lines in two zones, and no patient demonstrated signs for lysis. At a mean of 10-year (SD 0.8, 8.7-11.3) follow-up, mean OHS was 39 (SD 10.3, range 7-48) and 94% of patients reported being very satisfied or satisfied with their THA.

CONCLUSIONS

The Olympia stem demonstrated excellent 10-year PROMs and very high rates of stem survivorship at final follow-up beyond 15 years.

The successful migration of total joint arthroplasty from the hospital inpatient to outpatient ASC setting

BACKGROUND

This study was undertaken to analyze the clinical results and complication rate of patients undergoing outpatient total joint arthroplasty by a single orthopedic group. All surgeries were performed in the practice-owned ambulatory surgery center (ASC).

METHODS

All patients indicated for outpatient total joint arthroplasty from 2016-2019 with complete pre and post-operative patient reported outcomes were enrolled in the study including hip, knee and partial knee replacements. Patient reported outcomes including HOOS, KOOS and VR-12 were collected at six months. Patient complication and satisfaction data was also collected.

RESULTS

There were 1007 patients enrolled in the study. At six months, THA HOOS and VR-12 scores improved to 82.2 and 54.5/45. TKA KOOS and VR-12 scores improved to an average of 74.3 and 54.0/43.6. At six months, UKA scores improved to an average of 73.6 and 55.1/41.2. All HOOS, KOOS and VR-12 PCS scores improvements were statistically significant (p < 0.001) and met MCID thresholds. A separate cohort of 1898 regionally tracked cases with comprehensive global complication data exhibited 111 complications (unplanned post-operative events generating a medical expense) including manipulation 13 (0.68%), DVT/PE 4 (0.2%), medical 45 (2.4%), wound 8 (0.4%), infection 8 (0.4%). Sixty-six outpatient cases (3.5%) experienced clinical complications requiring some form of additional treatment.

CONCLUSION

Outpatient joint arthroplasty performed in the ASC is safe and effective in appropriately selected patients with complication rates that compares favorably to inpatient procedures.

Migration Patterns for Revision Total Knee Arthroplasty in the United States as Reported in the American Joint Replacement Registry

BACKGROUND

Revision total knee arthroplasty (TKA) is associated with a higher complication rate and a greater cost when compared to primary TKA. Based on patient choice, referral, or patient transfers, revision TKAs are often performed in different institutions by different surgeons than the primary TKA. The aim of this study is to evaluate the effect of hospital size, teaching status, and revision indication on the migration patterns of failed primary TKA in patients 65 years of age and older.

METHODS

All primary and revision TKAs reported to the American Joint Replacement Registry from January 2012 through March 2020 were included and merged with the Centers for Medicare and Medicaid Services database. Migration was defined as a patient having a primary TKA and revision TKA performed at separate institutions by different surgeons.

RESULTS

In total, 9167 linked primary and revision TKAs were included in the analysis. Overall migration rates were significantly higher from small (<100 beds; P = .019), non-teaching institutions (P = .002) driven primarily by patients diagnosed with infection. Infection patients had significantly higher migration rates from small (46.8%, P < .001), non-teaching (43.5%, P < .001) institutions, while migration rates for other causes of revision were statistically similar. Most patients migrated to medium or large institutions (84.7%) for revision TKA rather than small institutions (15.3%, P < .001) and to teaching (78.3%) rather than non-teaching institutions (21.7%, P < .001).

CONCLUSION

There is a diagnosis-dependent referral bias that affects the migration rates of infected primary TKA from small non-teaching institutions leading to a flow of more medically complex patients to medium and large teaching institutions for infected revision TKA.

Titanium Wear Particles Exacerbate S. epidermidis-Induced Implant-Related Osteolysis and Decrease Efficacy of Antibiotic Therapy

Total joint arthroplasty (TJA) surgeries are common orthopedic procedures, but bacterial infection remains a concern. The aim of this study was to assess interactions between wear particles (WPs) and immune cells in vitro and to investigate if WPs affect the severity, or response to antibiotic therapy, of a Staphylococcus epidermidis orthopedic device-related infection (ODRI) in a rodent model. Biofilms grown on WPs were challenged with rifampin and cefazolin (100 µg/mL) to determine antibiotic efficacy. Neutrophils or peripheral blood mononuclear cells (PBMCs) were incubated with or without S. epidermidis and WPs, and myeloperoxidase (MPO) and cytokine release were analyzed, respectively. In the ODRI rodent model, rats (n = 36) had a sterile or S. epidermidis-inoculated screw implanted in the presence or absence of WPs, and a subgroup was treated with antibiotics. Bone changes were monitored using microCT scanning. The presence of WPs decreased antibiotic efficacy against biofilm-resident bacteria and promoted MPO and pro-inflammatory cytokine production in vitro. WPs exacerbated osteolytic responses to S. epidermidis infection and markedly reduced antibiotic efficacy in vivo. Overall, this work shows that the presence of titanium WPs reduces antibiotic efficacy in vitro and in vivo, induces proinflammatory cytokine release, and exacerbates S. epidermidis-induced osteolysis.

The Effects of Depression and Anxiety on 90-day Readmission Rates After Total Hip and Knee Arthroplasty

Background

Patients undergoing total joint arthroplasty have higher rates of anxiety, depression or anxiety and depression than the general population and higher costs of care, which lead to higher levels of postoperative dissatisfaction and readmission rates. We evaluated the readmission rates of patients undergoing total hip or knee arthroplasty with diagnoses of anxiety, depression, or both.

Methods

Our hospital's prospectively collected data from Michigan's statewide total joint database were reviewed from 2013 to 2018. Rates of anxiety, depression or anxiety and depression were determined based on preoperative anxiolytic or antidepressant medications using National Drug Codes.

Results

A total of 4107 cases were included. Of which 4.28% had a readmission within the 90-day global period, and 12% had a history of depression or anxiety or both. For the entire cohort, those on anxiolytic medication were 153% more likely to be readmitted than those not on medication (P = .017). When comparing total hip arthroplasty (THA) or total knee arthroplasty (TKA), patients taking anxiolytic medication and undergoing TKA were 120% more likely to undergo readmission within 90 days (P = .021). Patients on depression medication alone were not at increased risk of readmission in the TKA cohort (P = .991). For THA, neither diagnosis appeared a risk factor for readmission (P = .852).

Conclusions

Patients with depression, anxiety, or both undergoing TKA were at a statistically significant risk of readmission within 90 days compared with patients without these diagnoses. Anxiety and depression were both risk factors for readmission, but anxiety appeared to have a more significant impact. Patients undergoing THA on the other hand did not appear to share this risk profile.

Temporal changes in sleep quality and knee function following primary total knee arthroplasty: a prospective study

PURPOSE

Several patient-reported outcome measures (PROMs) have been used to assess improvement in the quality of life following total knee arthroplasty (TKA). However, there is paucity of studies evaluating the sleep quality and knee function following TKA. The primary aim of our study was to evaluate the sleep quality and knee function in primary TKA patients using the Pittsburgh Sleep Quality Index (PSQI) and Knee Society Score (KSS), respectively. The secondary aim was to assess the correlation between the two outcome measures over the course of first post-operative year following TKA.

METHODS

One hundred sixty-eight patients (female-140/male-28) with mean age of 64.63 years (± 7.50) who underwent 168 primary unilateral TKA using a cemented posterior-stabilised implant without patella resurfacing between June 2018 and October 2018 were included in the study. Global PSQI and KSS were recorded pre-operatively and post-operatively weekly up to six weeks and at one year. Body mass index (BMI) and Charlson comorbidity index (CCI) were recorded during pre-operative assessment.

RESULTS

Mean(± SD) BMI and CCI were 28.45(± 4.64) and 2.48(± 0.93), respectively. Pre-operative global PSQI of 1.98(± 0.97) increased to 13.48(± 3.36) in the first post-operative week (p < 0.001) and remained high during all the six weeks following TKA (p < 0.001), whereas at the first post-operative year, it reduced to 2.10(± 1.15) (p = 0.15). Pre-operative KSS of 52.00(± 9.98) increased to 71.67(± 6.58) and 85.49(± 4.67) at 6 weeks and the first post-operative year respectively (p < 0.001). Pre-operative global PSQI had moderate correlation with pre-operative KSS (r = 0.39) (p < 0.001). Strong correlation was noted between pre-operative global PSQI and six week post-operative KSS (r = 0.47) (p < 0.001). Low correlation was noted between pre-operative global PSQI and KSS at the first post-operative year (r = 0.10, p = 0.19) following TKA. Multiple regression analysis revealed age, CCI, and pre-operative range of motion as independent predictors of global PSQI.

CONCLUSIONS

Patients undergoing TKA experience changes in sleep quality but report an overall improvement in knee function during the first post-operative year. Sleep quality has moderate to strong correlation with knee function in the early post-operative period beyond which there is a low correlation with knee function thereby suggesting a transient phenomenon. Hence patients undergoing TKA can be appropriately counselled regarding the variation in sleep quality in the post-operative period and reassured accordingly.

Comparing Complication Rates After Elective Total Knee Arthroplasty Delivered Or Purchased By The VA

The Department of Veterans Affairs (VA) both delivers health care in its own facilities and, increasingly, purchases care for veterans in the community. Policy makers, administrators, health care providers, and veterans frequently face decisions about which services should be delivered versus purchased by the VA. Comparisons of quality across settings are essential if veterans are to receive care that is consistently accessible, patient centered, effective, and safe. We compared risk-adjusted major postoperative complication rates for total knee arthroplasties that were delivered in VA facilities versus purchased from community providers. Overall, adjusted complication rates were significantly lower for arthroplasties delivered by the VA compared with those that were purchased. However, hospital-level comparisons revealed five locations where VA-purchased care outperformed VA-delivered care. As the amount of VA-purchased care continues to increase under the Veterans Access, Choice, and Accountability Act of 2014 and the VA Maintaining Internal Systems and Strengthening Integrated Outside Networks Act of 2018, these results support VA monitoring of overall and local comparative hospital performance to improve the quality of the care that the VA delivers while ensuring optimal outcomes in VA-purchased care.

Temporal Trends in Revision Total Hip and Knee Arthroplasty from 2008 to 2018: Gaps and Opportunities

BACKGROUND

An overall assessment of how patient demographic characteristics and comorbidities are improving or worsening can allow better understanding of the value of revision total joint arthroplasty (TJA). Therefore, the purpose of this study was to identify patient demographic characteristics and comorbidities trends and episode-of-care outcome trends from 2008 to 2018 in patients undergoing revision TJA.

METHODS

The National Surgical Quality Improvement Program database was queried to identify patient demographic characteristics, comorbidities, and episode-of-care outcomes in patients undergoing revision TJA from 2008 to 2018 (n = 45,706). Pairwise t tests and pairwise chi-square tests were performed on consecutive years with Bonferroni correction. Trends were assessed using the 2-tailed Mann-Kendall test of the temporal trend.

RESULTS

Among patients undergoing revision TJA, there was no clinically important difference, from 2008 to 2018, in age, body mass index (BMI), percentages with >40 kg/m2 BMI, diabetes (18.8% to 19%), chronic obstructive pulmonary disease (4.1% to 5.4%), congestive heart failure within 30 days (0% to 1%), or acute renal failure (0% to 0.2%). However, modifiable comorbidities including smoking status (14.7% to 12.0%; p = 0.01), hypertension (66% to 26.0%; p = 0.02), anemia (34.5% to 26.3%; p < 0.001), malnutrition (10.4% to 9.3%; p = 0.004), and overall morbidity or mortality probability have improved, with a decrease in the hospital length of stay and 30-day readmission and a significant increase in home discharge (p < 0.001 for all).

CONCLUSIONS

Time-difference analysis demonstrated that the overall health status of patients undergoing revision TJA improved from 2008 to 2018. However, formal time-trend analysis demonstrated improvements to a lesser degree. The multidisciplinary effort to improve value-based metrics including patient comorbidity optimization and episode-of-care outcomes for primary TJA has been shown to potentially have an impact on revision TJA.

LEVEL OF EVIDENCE

Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Gentamicin-Releasing Titania Nanotube Surfaces Inhibit Bacteria and Support Adipose-Derived Stem Cell Growth in Cocultures

Infection is the second leading cause of failure of orthopedic implants following incomplete osseointegration. Materials that increase the antimicrobial properties of surfaces while maintaining the ability for bone cells to attach and proliferate could reduce the failure rates of orthopedic implants. In this study, titania nanotubes (Nts) were modified with chitosan/heparin polyelectrolyte multilayers (PEMs) for gentamicin delivery. The antimicrobial activity of the surfaces was tested by coculturing bacteria with mammalian cells. Over 60% of gentamicin remained on the surface after an initial burst release on the first day. Antimicrobial activity of these surfaces was determined by exposure to Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) for up to 24 h. Gentamicin surfaces had less live E. coli and S. aureus by 6 h and less E. coli by 24 h compared to Nt surfaces. S. aureus and human adipose-derived stem cells (hADSCs) were cocultured on surfaces for up to 7 days to characterize the so-called "race to the surface" between bacteria and mammalian cells, which is hypothesized to ultimately determine the outcome of orthopedic implants. By day 7, there was no significant difference in bacteria between surfaces with gentamicin adsorbed on the surface and surfaces with gentamicin in solution. However, gentamicin delivered in solution is toxic to hADSCs. Alternatively, gentamicin presented from PEMs enhances the antimicrobial properties of the surfaces without inhibiting hADSC attachment and cell growth. Delivering gentamicin from the surfaces is therefore superior to delivering gentamicin in solution and represents a strategy that could improve the antimicrobial activity of orthopedic implants and reduce risk of failure due to infection, without reducing mammalian cell attachment.