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Use of molecular sequencing modalities in periprosthetic joint infection diagnosis and organism identification has gained popularity recently. To date, there is no diagnostic test that reliably predicts infection eradication in patients with antibiotic spacers. The purpose of this study was to compare the diagnostic accuracy of next-generation sequencing (NGS), culture, the Musculoskeletal Infection Society (MSIS) criteria, and the criteria by Parvizi et al in patients with antibiotic spacers. In this retrospective study, aspirate or tissue samples were collected from 38 knee and 19 hip antibiotic spacers for routine diagnostic workup for the presence of persistent infection and sent to the laboratory for NGS. The kappa statistic along with statistical differences between diagnostic studies were calculated using the chi-square test for categorical data. The kappa coefficient for agreement between NGS and culture was 0.27 (fair agreement). The percentages of positive and negative agreement were 22.8% and 42.1%, respectively, with a total concordance of 64.9%. There were 12 samples that were culture positive and NGS negative. Eight samples were NGS positive but culture negative. The kappa coefficient was 0.42 (moderate agreement) when comparing NGS with MSIS criteria. In our series, NGS did not provide sufficient agreement compared with culture or MSIS criteria in the setting of an antibiotic spacer. A reliable diagnostic indicator for reimplantation has yet to be identified. [ Orthopedics . 202x;4x(x);xx–xx.]

As value-based reimbursement models mature, understanding the potential trade-off between inpatient lengths of stay and complications or need for costly postacute care becomes more pressing. Understanding and predicting a patient's expected baseline length of stay may help providers understand how best to decide optimal discharge timing for high-risk total joint arthroplasty (TJA) patients.A retrospective review was conducted of 37,406 primary total hip (17,134, 46%) and knee (20,272, 54%) arthroplasties performed at two high-volume, geographically diverse, tertiary health systems during the study period. Patients were stratified by 3 binary outcomes for extended inpatient length of stay: 72 + hours (29%), 4 + days (11%), or 5 + days (5%). The predictive ability of over 50 sociodemographic/comorbidity variables was tested. Multivariable logistic regression models were created using institution #1 (derivation), with accuracy tested using the cohort from institution #2 (validation).During the study period, patients underwent an extended length of stay with a decreasing frequency over time, with privately insured patients having a significantly shorter length of stay relative to those with Medicare (1.9 versus 2.3 days, P.0001). Extended stay patients also had significantly higher 90-day readmission rates (P.0001), even when excluding those discharged to postacute care (P .01). Multivariable logistic regression models created from the training cohort demonstrated excellent accuracy (area under the curve (AUC): 0.755, 0.783, 0.810) and performed well under external validation (AUC: 0.719, 0.743, 0.763). Many important variables were common to all 3 models, including age, sex, American Society of Anesthesiologists (ASA) score, body mass index, marital status, bilateral case, insurance type, and 13 comorbidities.An online, freely available, preoperative clinical decision tool accurately predicts risk of extended inpatient length of stay after TJA. Many risk factors are potentially modifiable, and these validated tools may help guide clinicians in preoperative patient counseling, medical optimization, and understanding optimal discharge timing.

There is contradicting evidence on the diagnostic value of inflammatory biomarkers for periprosthetic joint infection (PJI). We sought to quantify the sensitivity of D-dimer for acute and chronic PJI diagnosis and evaluate D-dimer lab values in the 90-day postoperative window in a control cohort of primary joint arthroplasty patients for comparison.An institutional database was queried for patients undergoing revision procedures for PJI after total hip arthroplasty (THA) and total knee arthroplasty (TKA) from 2014 to present. CRP, ESR, and D-dimer were collected within 90 days pre and postoperatively and sensitivities for the diagnosis of PJI were calculated. The control group included patients who underwent a negative diagnostic workup for deep venous thrombosis (DVT) or pulmonary embolus (PE) and had a D-dimer lab collected within 90 days postoperatively from primary total joint arthroplasty (TJA).A total of 604 PJI patients were identified, and 81 patients had D-dimer, ESR, and CRP collected. There were 50/81 acute PJI patients and 31/81 chronic PJI patients who had median D-dimer values of 2,136.5 ng/mL [interquartile range (IQR): 1,642-3,966.5] and 3,336 ng/mL [IQR: 1,976-5,594]. Only the chronic PJI group had significantly higher D-dimer values when compared to the control cohort (P = .009). The sensitivity of D-dimer was calculated to be 92% and 93.5% in the acute and chronic PJI groups, respectively.Serum D-dimer may not have high diagnostic utility for acute PJI, especially in the setting of recent surgery; however, it still may be useful for patients who have chronic PJI.

Cutibacterium spp. is an emerging pathogen in total hip arthroplasty (THA) that is not well evaluated in the literature. This study reported on the presentation and management of THA complicated by positive intraoperative Cutibacterium cultures.This is a retrospective review of 27 revision THAs with positive monomicrobial intraoperative Cutibacterium cultures from 2014 to 2020 at one academic center. These patients were divided into two cohorts based on meeting Musculoskeletal Infection Society (MSIS) criteria for prosthetic joint infections (PJI). Patient demographics, preoperative labs, and hip aspirate results were collected. Procedure performed, postoperative antibiotic regimens, and repeat infections were recorded. Data were compared with univariate analysis.Nine of the 27 patients preoperatively met MSIS criteria for PJI. Patients with positive MSIS criteria had significantly higher median synovial cell count (P = .048) and neutrophil percentage in a preoperative aspirate (P = .050). Eight patients with positive MSIS criteria received six weeks of postoperative antibiotics compared to two patients with negative criteria. Two patients with positive MSIS criteria had a postoperative infection that required further surgical intervention. Four patients with negative criteria who required further surgical intervention did not receive postoperative antibiotics after initial revision.While often categorized as a contaminant, Cutibacterium is an increasingly recognized pathogen in THA. Cutibacterium can often present with normal serology, which may result in misdiagnosis as aseptic THA failure. Without the administration of postoperative antibiotics after positive cultures, there is a risk for persistent infection requiring further surgical intervention.

Background Enterobacter sp. is a gram-negative, often drug-resistant bacillus that is classically identified from mucosal surfaces, such as pulmonary or urinary tracts. Despite its virulence, Enterobacter represents a less common pathogen in prosthetic joint infections (PJI). This study aims to resolve the current paucity of described clinical characteristics and treatment success of Enterobacter PJI. Methods Thirty-three patients with Enterobacter aerogenes-, cloaecae/asburiae-, or hormachei-positive PJIs were identified at a single institution. Infection clearance was defined as absence of infection or repeat surgery at one year and off all adjunct antibiotic therapy. Patient demographics, PJI characteristics, treatments, and clinical outcomes were compared between patients with and without clearance. Results In this cohort, mean age was 66.8 years (SD: 11.6), mean BMI was 31.0 (SD: 7.1), and mean Elixhauser Comorbidity Score was 9.1 (SD: 4.5). 54.5% had a prior PJI in the same joint, and 87.9% had more than one prior surgery in that joint. Median time of PJI diagnosis after surgery was 22 days [IQR: 18-60]. Patients initially treated with debridement antibiotics and implant retention (n=11) had a 45.5% clearance rate, compared to 23.1% for 2-stage exchange (n=13) and 44.4% for those requiring resection arthroplasty or amputation (n=9). With a median follow-up of 2.9 years, final joint outcomes included resection arthroplasty in 9 (27.3%), above-knee amputation in 7 (21.2%), definitive treatment with an articulating spacer in 6 (18.2%), and arthrodesis in 2 (6.1%) patients. Conclusion Enterobacter PJI often presents acutely and is a difficult pathogen to treat. The outcomes of our cohort reflect the virulence of Enterobacter, with high rates of failure and ultimate joint- or limb-sacrificing procedure. Despite being a less common cause of PJI, prognosis is exceptionally poor with traditional treatment algorithms when compared to historical cohorts of more common pathogens. Disclosures William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

Background Escherichia Coli (E coli) is a gram-negative rod that can cause devastating periprosthetic joint infections (PJIs) in patients with total hip and knee replacements (THA/TKA). Minimal literature exists on outcomes of E coli PJIs. Methods Retrospective review of our institution’s electronic medical record from 2009-2020 identified 21 patients that met MusculoSkeletal Infection Society criteria for E coli hip or knee PJI. Primary outcome was 1-year infection clearance - eradication of infection off antibiotics with no further surgeries for 1 year after completion of standard postoperative antibiotics. Minimum followup was 1 year. Results We analyzed 21 patients (mean age 66.6 yrs, 47.6% male, 23.8% nonWhite, 38.1% knee PJIs). There were 11 acute, 8 acute hematogenous (AH), and 2 chronic PJIs. Several patients had recent gastrointestinal/urinary tract surgery (14.3%), recurrent urinary tract infections (9.5%), or >1 E coli urine culture Conclusion E coli PJI 1-year infection clearance is poor, with DAIR being the most common yet least effective surgical treatment. Most E coli PJIs occurred postoperatively as opposed to hematogenously, as is sometimes assumed. This serves as a foundation for future studies evaluating E coli treatment outcomes. Disclosures William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

Background Pseudomonas species are a less common but devastating pathogen family in prosthetic joint infections (PJI). Despite advancements in management, Pseudomonas PJI remains particularly difficult to treat due to fewer antibiotic options and robust biofilm formation. The purpose of this study was to better evaluate outcomes after Pseudomonas PJI treatment. Methods All hip or knee PJIs, at a single institution, with positive Pseudomonas culture were analyzed. 51 patients (29 hips and 22 knees) meeting inclusion criteria were identified. The primary outcome of interest was infection clearance at 1-year after surgical treatment, defined as reassuring aspirate without ongoing antibiotic treatment or death within one year post-operatively. Monomicrobial and polymicrobial infections were evaluated separately. Results Among monomicrobial PJIs, ten (50.0%) patients were clear of infection at one year post-operatively. Patients treated with 2-stage exchange (n=11) had a 1-year clearance rate of 54.5% compared to 60.0% with DAIR (n=5) and 25.0% with resection or amputation (n=4). Two of six patients treated with fluoroquinolone monotherapy met 1-year infection clearance, despite fluoroquinolone sensitivity, compared to four of five patients meeting 1-year clearance when treated with combined intravenous and oral therapy for at least 6 weeks. Resistance to anti-pseudomonal agents was infrequent (20%, n=4/20), and three of ten mono- and polymicrobial PJI patients with recurrent Pseudomonas PJI developed resistance to anti-pseudomonal therapy. Polymicrobial infections were the most common presentation (54.9%) of Pseudomonas positive PJI with a mortality rate of 46.4% (n=13/28) at a median follow-up of 4.2 years [IQR: 3.4-5.7]. Conclusion Despite surgical and antibiotic treatment regimens consistent with traditional treatment algorithms, our data portrays poor clearance rate of Pseudomonas PJI with relatively poor outcomes in patients treated with oral or intravenous monotherapy. Pseudomonas infections are difficult to eradicate and likely require deviations from classical therapeutic protocols to improve treatment success. Disclosures William A. Jiranek, MD, Biomech Holdings LLC: Stocks/Bonds|DePuy, A Johnson & Johnson Company: IP royalties Thorsten M. Seyler, MD, PhD, Heraeus: Paid consultant|Pattern Health: IP royalties|Restor3d: IP royalties|Smith & Nephew: Paid consultant|Total Joint Orthopedics: Paid consultant|Zimmer: research.

There is scant literature evaluating varus-valgus constrained (VVC) prostheses in contemporary revision total knee arthroplasty (TKA). Therefore, we aimed to evaluate the durability of VVC revision TKA with selective use of cones.A retrospective review of 194 revision TKAs with VVC was performed from August 2005 through February 2018 at a single institution. The final cohort consisted of 168 TKAs with a mean follow-up of 6 years. Stems were used in all but 1 TKA, tibial cones in 48%, and femoral cones in 19%. Anderson Orthopaedic Research Institute classification in femurs was 1 in 57, 2A in 33, 2B in 62, 3 in 16, and in tibias, 1 in 42, 2A in 29, 2B in 81, and 3 in 16.Survival analysis showed that 93% were free of revision for aseptic component loosening, 76% were free of revision for any reason, and 74% were free of reoperation at 6 years. Anderson Orthopaedic Research Institute 3 femur or tibia, age65 years, and progressive radiographic changes were associated with an increased risk of revision for aseptic loosening (P.05). Progressive radiographic changes were seen in 19% of femoral and 16% of tibial constructs. The most common reason for re-revision was periprosthetic joint infection (65%).VVC revision TKA with selective use of cones provided a reasonable outcome as 93% were free of revision for aseptic loosening at 6 years. However, given the rate of patients with progressive radiographic changes and survivorship free of reoperation of 74% at 6 years, long-term follow-up will help assess the durability of these constructs.

The objective of this study was to assess the feasibility of using an electronic clinical quality measure (eCQM) to assess inpatient respiratory depression rates following elective primary total hip or total knee arthroplasty using data routinely collected in electronic health records. Measure testing was conducted at two large urban, academic health systems - Mass General Brigham and a geographically distant system in southern U.S. The risk-adjusted inpatient respiratory depression rates were 3.83 and 2.73% for the two health systems, respectively. Clinician group rates ranged from 1.40 to 4.35%, demonstrating opportunity for improvement. Both the data and measure specifications showed strong reliability and validity to allow for calculation of accurate and comparable rates of inpatient respiratory depression.

The objective of this study was to assess the feasibility of using an electronic clinical quality measure (eCQM) to assess inpatient respiratory depression rates following elective primary total hip or total knee arthroplasty using data routinely collected in electronic health records. Measure testing was conducted at two large urban, academic health systems – Mass General Brigham and a geographically distant system in southern U.S. The risk-adjusted inpatient respiratory depression rates were 3.83 and 2.73% for the two health systems, respectively. Clinician group rates ranged from 1.40 to 4.35%, demonstrating opportunity for improvement. Both the data and measure specifications showed strong reliability and validity to allow for calculation of accurate and comparable rates of inpatient respiratory depression.

Revision total knee arthroplasty (TKA) involves varying levels of case complexity and costs depending on the following: (1) number of components revised, (2) duration of operating room time, and (3) length of hospital stay. However, the cost associated with different types of aseptic TKA revisions, based on number and type of components revised, is not well described. We sought to determine differences in cost associated with different revision types, and to correlate this with average national hospital and surgeon reimbursement based on current Centers for Medicare and Medicaid Services data.This is a retrospective review of aseptic revision TKAs performed at a single tertiary referral center from 2015 to 2018. Patient demographic data, operating room time, and direct surgery and total hospital costs obtained from an internal accounting database (Enterprise Performance Systems, Inc) were collected. Patients were stratified by the components revised (polyethylene liner only, tibia only, femur only, or both femur and tibia). We hypothesized that direct surgery and total hospital costs would increase as case complexity increased from poly exchange to single-component revisions and both-component revisions.In total, 106 patients were included (19 poly exchanges, 10 tibia-only revisions, 13 femur-only revisions, and 64 both-component revisions). Operating room time was significantly lower for poly exchange than all other groups (P.001). Direct surgery and total hospital costs were significantly lower for poly exchange than all other groups (P.001), and were significantly lower for tibia-only and femur-only revisions compared to both-component revisions (P.001). Average national surgeon reimbursement by Medicare decreased as a percentage of direct surgery cost as case complexity increased from poly exchange to tibia-only, femur-only, and both-component revisions. Total hospital cost per average Diagnosis Related Group weight was lowest for single-component revisions and highest for both-component revision.There are significant differences in cost associated with aseptic TKA revisions based on number and type of components revised. These differences may not be accurately reflected in reimbursement, and often represent a burden to those who treat complex revisions.

The Center for Medicare and Medicaid Services is faced with a challenge of decreasing the cost of care for total knee arthroplasty (TKA) but must make efforts to prevent patient selection bias in the process. Currently, no appropriate modifier codes exist for primary TKA based on case complexity. We sought to determine differences in perioperative parameters for patients with complex primary TKA with the hypothesis that they would require increased cost of care, prolonged care times, and have worse postoperative outcome metrics.We performed a single-center retrospective review from 2015 to 2018 of all primary TKAs. Patient demographics, medial proximal tibial angle (mPTA), lateral distal femoral angle (lDFA), flexion contracture, cost of care, and early postoperative outcomes were collected. Complex patients were defined as those requiring stems or augments, and multivariable logistic regression analysis and propensity score matching were performed to evaluate perioperative outcomes.About 1043 primary TKAs were studied, and 84 patients (8.3%) were deemed complex. For this cohort, surgery duration was greater (P.001), cost of care higher (P.001), and patients had a greater likelihood for 90-day hospital return. Deviation of mPTA and lDFA was significantly greater preoperatively before and after propensity score matching. Cut point analysis demonstrated that preoperative mPTA83Complex primary TKA may be identifiable preoperatively and those cases associated with prolonged operative time, excess hospital cost of care, and increased 90-day hospital returns. This should be considered in future reimbursement models to prevent patient selection bias, and a complexity modifier is warranted.

Aims Use of molecular sequencing methods in periprosthetic joint infection (PJI) diagnosis and organism identification have gained popularity. Next-generation sequencing (NGS) is a potentially powerful tool that is now commercially available. The purpose of this study was to compare the diagnostic accuracy of NGS, polymerase chain reaction (PCR), conventional culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al in the diagnosis of PJI. Methods In this retrospective study, aspirates or tissue samples were collected in 30 revision and 86 primary arthroplasties for routine diagnostic investigation for PJI and sent to the laboratory for NGS and PCR. Concordance along with statistical differences between diagnostic studies were calculated. Results Using the MSIS criteria to diagnose PJI as the reference standard, the sensitivity and specificity of NGS were 60.9% and 89.9%, respectively, while culture resulted in sensitivity of 76.9% and specificity of 95.3%. PCR had a low sensitivity of 18.4%. There was no significant difference based on sample collection method (tissue swab or synovial fluid) (p = 0.760). There were 11 samples that were culture-positive and NGS-negative, of which eight met MSIS criteria for diagnosing infection. Conclusion In our series, NGS did not provide superior sensitivity or specificity results compared to culture. PCR has little utility as a standalone test for PJI diagnosis with a sensitivity of only 18.4%. Currently, several laboratory tests for PJI diagnosis should be obtained along with the overall clinical picture to help guide decision-making for PJI treatment. Cite this article: Bone Joint J 2021;103-B(1):26–31.

Few studies have investigated the influence of trainee involvement on inpatient satisfaction scores in the postoperative joint arthroplasty setting. This study compares Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey scores at academic and private health care centers to assess the impact of trainees on patient satisfaction. From 2013 to 2017, 3454 HCAHPS surveys were collected at the investigating institution from patients who underwent primary total hip and total knee arthroplasty. Surveys were categorized based on the inpatient practice setting—academic hospitals included orthopedic residents and medical students who were involved in perioperative care, whereas private settings did not have trainee involvement. Patient demographics, including age, body mass index, sex, and American Society of Anesthesiologists score, were retrospectively collected. A total of 2454 HCAHPS surveys from 2 academic hospitals and 1000 surveys from a private hospital were collected. Patients at the academic hospitals were more likely to report that symptoms to look out for were clearly explained (odds ratio, 1.882; P =.001), whereas patients from the private hospital were more likely to report that the hospital was always quiet at night (odds ratio, 1.271; P =.005). The overall satisfaction score was not significantly different between the academic and private settings (78.9 vs 80.2, respectively; P =.111). The overall hospital satisfaction score for patients undergoing primary total hip and knee arthroplasty was not significantly different between private and academic medical facilities. Thus, this study supports the idea that training future orthopedic surgeons will not negatively impact patient satisfaction scores in a way that affects reimbursement. [ Orthopedics . 2022;45(5):276–280.]

Background Psychological distress can negatively influence disability, quality of life, and treatment outcomes for individuals with hip and knee osteoarthritis (OA). Clinical practice guidelines recommend a comprehensive disease management approach to OA that includes the identification, evaluation, and management of psychological distress. However, uncertainty around the best psychological screening and assessment methods, a poor understanding of the heterogeneity of psychological distress in those with OA, and lack of guidance on how to scale treatment have limited the growth of OA care models that effectively address individual psychological needs. Questions/purposes (1) Across which general and pain-related psychological distress constructs do individuals seeking conservative care for hip or knee OA report higher scores than the general population of individuals seeking conservative care for musculoskeletal pain conditions? (2) What common psychological phenotypes exist among nonsurgical care-seeking individuals with hip or knee OA? Methods The sample included participants from the Duke Joint Health Program (n = 1239), a comprehensive hip and knee OA care program, and the Optimal Screening for Prediction of Referral and Outcome (OSPRO) cohort studies (n = 871) comprising individuals seeking conservative care for knee, shoulder, low back, or neck pain. At the initial evaluation, patients completed the OSPRO Yellow Flag (OSPRO-YF) Assessment Tool, which assesses 11 general and pain-related psychological distress constructs (depression, anxiety, fear of movement, self-efficacy for managing one's own pain). We used OSPRO-YF scores to compare levels of psychological distress between the cohorts. Cohen's d effect sizes were calculated to determine the magnitude of differences between the groups, with d = 0.20, d = 0.50, and d = 0.80 indicating small, medium, and large effect sizes, respectively. We used a latent class analysis to derive psychological distress phenotypes in people with OA based on the 11 OSPRO-YF psychological distress indicators. Psychological distress phenotypes are characterized by specific mood, belief, and behavioral factors that differentiate subgroups within a population. Phenotyping can help providers develop scalable treatment pathways that are better tailored to the common needs of patients. Results Patients with OA demonstrated higher levels of general and pain-related psychological distress across all psychological constructs except for trait anxiety (that is, anxiety level as a personal characteristic rather than as a response to a stressful situation, like surgery) with small-to-moderate effect sizes. Characteristics with the largest effect sizes in the OA and overall OSPRO cohort were (Cohen's d) general anxiety (-0.66, lower in the OA cohort), pain catastrophizing (the tendency to ruminate over, maginfiy, or feel helpless about a pain experience, 0.47), kinesiophobia (pain-related fear of movement, 0.46), pain self-efficacy (confidence in one's own ability to manage his or her pain, -0.46, lower in the OA cohort), and self-efficacy for rehabilitation (confidence in one's own ability to perform their rehabilitation treatments, -0.44, lower in the OA cohort). The latent class analysis yielded four phenotypes (% sample): high distress (52%, 647 of 1239), low distress (26%, 322 of 1239), low self-efficacy and acceptance (low confidence in managing and willingness to accept pain) (15%, 186 of 1239), and negative pain coping (exhibiting poor pain coping skills) (7%, 84 of 1239). The classification error rate was near zero (2%), and the median of posterior probabilities used to assign subgroup membership was 0.99 (interquartile range 0.98 to 1.00), both indicating excellent model performance. The high-distress group had the lowest mean age (61 ± 11 years) and highest levels of pain intensity (6 ± 2) and disability (HOOS JR: 50 ± 15; KOOS JR: 47 ± 15), whereas the low-distress group had the highest mean age (63 ± 10 years) and lowest levels of pain (4 ± 2) and disability (HOOS JR: 63 ± 15; KOOS JR: 60 ± 12). However, none of these differences met or exceeded anchor-based minimal clinically important difference thresholds. Conclusions General and pain-related psychological distress are common among individuals seeking comprehensive care for hip or knee OA. Predominant existing OA care models that focus on biomedical interventions, such as corticosteroid injection or joint replacement that are designed to directly address underlying joint pathology and inflammation, may be inadequate to fully meet the care-related needs of many patients with OA due to their underlying psychological distress. We believe this because biomedical interventions do not often address psychological characteristics, which are known to influence OA-related pain and disability independent of joint pathology. Healthcare providers can develop new comprehensive hip and knee OA treatment pathways tailored to these phenotypes where services such as pain coping skills training, relaxation training, and psychological therapies are delivered to patients who exhibit phenotypes characterized by high distress or negative pain coping. Future studies should evaluate whether tailoring treatment to specific psychological phenotypes yields better clinical outcomes than nontailored treatments, or treatments that have a more biomedical focus. Level of evidence Level III, diagnostic study.

Prosthetic joint infections (PJIs) are typically caused by Staphylococcus aureus and coagulase-negative Staphylococci species. Corynebacterium species are microorganisms of the human skin and mucous membranes that are often considered contaminants when grown in culture. In the past, Corynebacterium species were often classified as diphtheroids based on growing as gram-positive rods in aerobic environments, but with advances in technology, the identification of Corynebacterium species has improved. Corynebacterium can cause infection, but there are few case reports of orthopaedic infection. We present 3 cases of total hip arthroplasty and 3 cases of total knee arthroplasty PJI caused by Corynebacterium species. We found a high failure rate of surgical treatment of Corynebacterium PJI, defined as reoperation for infection. This information adds to the limited literature on these organisms in total joint arthroplasty PJI.

Background: Recent evidence describes which interventions are driving insurance payments in the management of osteoarthritis (OA) before total knee arthroplasty (TKA); however, relatively little is known about how these costs are distributed among patients. Methods: We reviewed the Humana claims database for patients who underwent primary TKA from 2009 to 2016. Insurance payments for treatment, imaging, and evaluation and management were calculated from OA diagnosis to TKA, the distribution of payments was determined, and a high-payment group was identified by determining the point at which patients began to account for a disproportionate percentage of payments. This group of high-payment patients was compared with remaining patients (low-payment patients) based on demographic factors and nonarthroplasty payments and utilization. Results: The top 30% of patients accounted for more than 70% of nonarthroplasty payments. High-payment patients were more likely to be younger, female, and more comorbid. Median time from diagnosis to TKA for high-payment patients was 3 times longer than that for low-payment patients (654 days [320-1191] vs 204 days [68-582], P < .001), and median payment per patient was more than 5 times higher ($1891 [1405-2782] vs $362 [198-613], P < .001). Conclusions: Identification of high-payment patients in the management of knee OA may allow for targeted care pathways and cost-reduction strategies in the nonarthroplasty period, although additional studies are necessary to further characterize this population and efficiently recognize appropriate TKA candidates and timing. Keywords: Osteoarthritis, Total knee arthroplasty, Health insurance, Reimbursement payments, Cost distribution

Smjernice za prevenciju tromboembolijskih incidenata prilikom ortopedskih zahvata na kuku i koljenu.

A fully-automated deep learning algorithm matched performance of radiologists in assessment of knee osteoarthritis severity in radiographs using the Kellgren-Lawrence grading system. Purpose To develop an automated deep learning-based algorithm that jointly uses Posterior-Anterior (PA) and Lateral (LAT) views of knee radiographs to assess knee osteoarthritis severity according to the Kellgren-Lawrence grading system. Materials and methods We used a dataset of 9739 exams from 2802 patients from Multicenter Osteoarthritis Study (MOST). The dataset was divided into a training set of 2040 patients, a validation set of 259 patients and a test set of 503 patients. A novel deep learning-based method was utilized for assessment of knee OA in two steps: (1) localization of knee joints in the images, (2) classification according to the KL grading system. Our method used both PA and LAT views as the input to the model. The scores generated by the algorithm were compared to the grades provided in the MOST dataset for the entire test set as well as grades provided by 5 radiologists at our institution for a subset of the test set. Results The model obtained a multi-class accuracy of 71.90% on the entire test set when compared to the ratings provided in the MOST dataset. The quadratic weighted Kappa coefficient for this set was 0.9066. The average quadratic weighted Kappa between all pairs of radiologists from our institution who took part in the study was 0.748. The average quadratic-weighted Kappa between the algorithm and the radiologists at our institution was 0.769. Conclusion The proposed model performed demonstrated equivalency of KL classification to MSK radiologists, but clearly superior reproducibility. Our model also agreed with radiologists at our institution to the same extent as the radiologists with each other. The algorithm could be used to provide reproducible assessment of knee osteoarthritis severity.

Coagulase-negative staphylococci (CoNS) are biofilm-producing pathogens whose role in periprosthetic joint infection (PJI) is increasing. There is little data on the prognosis and treatment considerations in the setting of PJI. We sought to evaluate the clinical characteristics, outcomes, and complications in these patients.This is a retrospective cohort study of adult patients at a single tertiary medical center from 2009 to 2020 with culture-proven CoNS PJI after total knee arthroplasty, as diagnosed by Musculoskeletal Infection Society criteria. The primary outcome was treatment success, with failure defined as recurrent CoNS PJI, recurrent PJI with a new pathogen, and/or chronic oral antibiotic suppression at one year postoperatively.We identified 55 patients with a CoNS total knee arthroplasty PJI with a mean follow-up of 29.8 months (SD: 16.3 months). The most commonly isolated organism was Staphylococcus epidermidis (n = 36, 65.5%). The overall prevalence of methicillin resistance was 63%. Surgical treatment included surgical debridement, antibiotics, and implant retention in 25 (45.5%) cases and two-stage revision (22 articulating and eight static antibiotic-impregnated spacers). At one-year follow-up, only 47% of patients had successful management of their infection. The surgical debridement, antibiotics, and implant retention cohort had the higher rate of treatment failure (60.0%) compared to two-stage revision (46.7%).These results indicate a poor rate of success in treating CoNS PJI. This likely represents the interplay of inherent virulence through biofilm formation and decreased antibiotic efficacy.

This study aimed to better understand body mass index (BMI) change patterns and factors associated with BMI change before and after total hip arthroplasty (THA) in Class 2 and 3 obese patients, and assess if preoperative or postoperative BMI change affects postoperative clinical outcomes.We retrospectively reviewed World Health Organization Class 2 and 3 obese patients (BMI35.0 at surgery) who underwent THA at a tertiary medical center from 2010 to 2020. BMI was recorded at 1 year preoperatively (mean 11.6 months), and at most recent postoperative visit (mean 29.0 months). Baseline demographics and postoperative clinical outcomes were recorded.We reviewed 436 THAs with a mean age of 59.9 (11.5) years. Leading up to surgery 55.5% had unchanged BMI, and postoperatively 48.2% had unchanged BMI. Multivariate logistic regression revealed that those who lost BMI preoperatively were more likely to gain BMI postoperatively (odds ratio [OR] 3.28, confidence interval [CI] 1.83-5.97, P = .005), but those who gained5% BMI preoperatively had no association with BMI change postoperatively. Those in a higher BMI class preoperatively were less likely to gain BMI preoperatively (Class 3 obese patients: OR 0.001, CI 0.0002-0.004, P.001). African American patients were more likely to gain BMI preoperatively (OR 2.32, CI 1.16-4.66, P = .017). We did not detect an association between BMI change and postoperative clinical outcomes.In World Health Organization Class 2 or 3 obese patients, most maintained BMI between their first preoperative and final postoperative visit. Preoperatively, Class 3 obese patients were less likely to gain weight than Class 2 obese patients. The primary predictor of postoperative weight gain was preoperative weight loss. Weight change preoperatively and postoperatively were not associated with worse clinical outcomes.

Background and Purpose Existing osteoarthritis (OA) care models often fall short in addressing the many biological, psychological, social, and behavioral characteristics that contribute to disability. As US health care shifts towards value-based payment, there is an increasing need to develop and test scalable, cost-effective, and multi-modal OA care models. This administrative case report will describe the development and pilot of a new, value-based comprehensive care model for OA. Case Description The Joint Health Program (JHP) is a physical therapist-led conservative care model for individuals with hip and knee OA. In the JHP, physical therapists with specialized training in cognitive behavioral-theory based strategy function as the central care provider (ie, the primary osteoarthritis provider) who delivers evidence-based, psychologically informed interventions and coordinates care within a multi-disciplinary network of dietitians, behavioral health specialists, and orthopedic providers. The JHP is focused on enhancing patient engagement, shared decision making, self-management and multi-modal patient interaction, and long-term follow-up. Outcomes A value-based, comprehensive care program for OA led by physical therapists demonstrated feasibility and acceptability within a large, academic health care system, which has led to its early growth. Barriers to development and integration of the program were addressed through effective collaboration among health care providers, program and health system administrators, and executive leadership. Discussion The JHP serves as a model for future physical therapist-led, value-based care models that could be developed in other health care systems for OA and other chronic conditions. Future work will identify characteristics that predict program response and compare the effectiveness of this program to existing models of care.

Bundled reimbursement models for total knee arthroplasty (TKA) by the Center for Medicare and Medicaid Services have resulted in an effort to decrease the cost of care. However, these models may incentivize bias in patient selection to avoid excess cost of care. We sought to determine the impact of the Comprehensive Care for Joint Replacement (CJR) model at a single center.This is a retrospective review of primary TKA patients from July 2015 to December 2017. Patients were stratified by whether or not their surgery was performed before or after implementation of the CJR bundle. Patient demographic data including age, sex, and body mass index were collected in addition to Elixhauser comorbidities and American Society of Anesthesiologists score. In-hospital outcomes were then examined including surgery duration, length of stay, discharge disposition, and direct cost of care.A total of 1248 TKA patients (546 Medicare and 702 commercial insurance) were evaluated, with 27.0% undergoing surgery before the start of the bundle. Compared to patients following implementation of the bundle, there was no significant difference in age, gender, or body mass index. However, pre-CJR Medicare patients were more likely to have fewer Elixhauser comorbidities (P.001), prolonged length of stay (P.001), and greater discharges to inpatient facilities (P = .019). There was no significant difference in direct hospital costs or operative service time comparing pre-bundle and post-bundle patients.Implementation of the bundled reimbursement model did not result in biased patient selection at our institution; importantly, it also did not result in decreased hospital costs despite apparent improvement in value-based outcome metrics. This should be taken into consideration as future adaptations to reimbursement are made by the Center for Medicare and Medicaid Services.

Background The Center for Medicare and Medicaid Services (CMS) classifies reimbursement for total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on Medical Severity-Diagnosis Related Groups (MS-DRGs) 469 (with major complication/comorbidity) and 470 (without major complication/comorbidity). The validated Elixhauser comorbidity index includes 31 variables that may be associated with MS-DRG 469. However, we hypothesized that these comorbidities may not be the most predictive of increased cost of care. Methods Elixhauser comorbidities were retrospectively examined for 1243 TKAs and 897 THAs from 2013 to 2017 at a single center. Comorbidities were investigated in univariable analysis and significant variables associated with MS-DRG 469, and cost of care was further investigated in a multivariable regression to determine which were most predictive of the increased complexity classification assigned by CMS vs true increased cost of care. Results Thirty-nine patients (1.8%) were classified as MS-DRG 469. Univariable and multivariable logistic analysis revealed that coagulopathy, electrolyte disorders, neurodegenerative disorders, and psychosis were significantly associated with an increased complexity classification. These 4 comorbidities were also associated with increased cost of care; however, 13 additional comorbidities were also predictive of increased cost but not MS-DRG classification. Conclusions Patient comorbidities have been shown to increase complications and cost of care for arthroplasty patients. To date, however, the only risk adjustment provided has been the 469 DRG code. This study demonstrates little correlation to the current system with the most expensive diagnoses. Consequently, an expansion of the current risk adjustment system for THA and TKA provided by CMS appears greatly needed.

Inflammatory demyelinating polyneuropathy is a rare but devastating condition. Guillain-Barré syndrome is the most common cause with acute inflammatory demyelinating polyneuropathy being the most common subtype that follows a monophasic course and does not recur. Chronic inflammatory demyelinating polyneuropathy occurs when symptoms persist for greater than 8 weeks. With many proposed etiologies, few reports have described acute inflammatory demyelinating polyneuropathy after total joint arthroplasty. To our knowledge, this is the first case report of chronic inflammatory demyelinating polyneuropathy developing after total hip arthroplasty that was further complicated by dislocation. Keywords: Guillain-Barré syndrome, Acute inflammatory demyelinating polyneuropathy, Chronic inflammatory demyelinating polyneuropathy, Inflammatory demyelinating polyneuropathy, Total hip arthroplasty, Dislocation

Conversion total hip arthroplasties (THAs) from prior free vascularized fibular grafting (FVFG) are infrequently reported in the literature. We characterized the perioperative outcomes of patients undergoing conversion THA and compared them with those of a matched cohort of patients undergoing primary THA for osteonecrosis of the femoral head and neck (ONFHN).The institutional database was queried for patients with FVFG requiring conversion to THA. This cohort was then matched 1:1 for age, gender, and American Society of Anesthesiologists (ASA) score for patients with ONFHN undergoing primary THA. Medical records were reviewed for intraoperative and postoperative complications, which were then compared between conversion and primary THA patient cohorts.Two hundred eighty-eight THA patients were included for analysis (144 patients with FVFG matched to 144 patients with ONFHN and no prior FVFG). Patients with prior FVFG who underwent THA had significantly greater operative time and blood loss (P.001). Although not significant, there were more intraoperative fractures in the FVFG cohort (P = .053). Postoperatively, patients with FVFG had significantly greater blood transfusions (P.001) and hematoma formation (P = .004) than the matched cohort. There was no difference in length of stay, discharge disposition, or venous thromboembolism; however, patients who underwent conversion THA showed increased deep infection (P = .044) and rate of return to the operating room (P = .010).Although there are numerous treatment strategies for patients with ONFHN, many patients will ultimately require THA. Patients undergoing conversion after FVFG are more likely to have complications including increased blood loss, hematoma formation, and intraoperative fractures. Consequently, surgeons should concentrate on preoperative optimization and prepare for specific technical challenges.

Stiffness after total knee arthroplasty (TKA) remains a challenging problem. Angiotensin receptor blockers (ARBs) have been associated with decreased muscle fibrosis. The aim of this study was to evaluate whether perioperative use of ARBs was associated with a reduction in arthrofibrosis and manipulation under anesthesia (MUA) in patients undergoing primary TKA at 90 days and 1 year postoperative. In this retrospective study, the authors used a national database to evaluate patients undergoing TKA for primary osteoarthritis from 2007 to 2017. They evaluated patients with filled prescriptions for ARBs within the study time frame and the specific type of ARB and its association with arthrofibrosis and MUA. After adjusting for age, sex, a comorbidity index, and obesity, any ARB or specific ARBs were not associated with a reduction in the rate of arthrofibrosis or MUA after TKA ( P ≥.05). Male sex, age 55 years or older, and obesity were associated with a reduction in the rate of arthrofibrosis and MUA after TKA ( P ≤.05). Studies should be performed to evaluate ARBs to see whether there is a more specific role in preventing joint stiffness in certain patient subpopulations following TKA. [ Orthopedics . 2021;44(2):e274–e280.]

BackgroundPatients undergoing total knee arthroplasty (TKA) have psychological comorbidities that influence recovery and functional outcomes. Resilience is a psychological construct defined as an individual's ability to adapt to adversity. Pain catastrophizing encompasses rumination, magnification, and helplessness that patients feel toward their pain. Pain catastrophizing is associated with poor function following surgery. Studies assessing the influence of resilience on postoperative outcomes have shown inconsistent findings and have not accounted for the influence of pain catastrophizing. We sought to identify (1) whether baseline pain catastrophizing and resilience are predictive of postoperative knee function, general physical health, and general mental health three months after TKA and (2) whether baseline pain catastrophizing and resilience are associated with preoperative knee function, general physical health, and general mental health.MethodsPatients undergoing TKA between January 2019 and November 2019 were included in this longitudinal cohort study. Demographics and questionnaires [Brief Resilience Scale (BRS), Pain Catastrophizing Scale (PCS), Knee injury and Osteoarthritis Outcome Score, Junior (KOOS, JR.) and Patient-Reported Outcomes Measurement Information System Physical and Mental Health (PROMIS PH and MH, respectively)] were collected preoperatively and 3 months postoperatively. Multivariable regression was used to test associations of preoperative BRS and PCS with postoperative outcomes.ResultsThe study cohort included 117 patients with a median age of 67.0 years (Q1-Q3: 59.0-72.0). Fifty-three percent of patients were women and 70.1% were white. In multivariable linear regression analyses, baseline pain catastrophizing did not demonstrate a significant association with postoperative 3-month knee function, (β = -0.08, p = 0.543), general physical health (β = -0.11, p = 0.313), or general mental health (β = 0.01, p = 0.919). Baseline resilience positively associated with postoperative knee function (β = 0.24, p = 0.019) and general physical health (β = 0.24, p = 0.013).ConclusionsOur prospective analysis suggests that resilience predicts postoperative knee function and general physical health in patients undergoing TKA. Given the inconsistent findings in this area of research, future studies should continue to delineate preoperative constructs that impact patients following surgery. Exploring interventions targeting the preoperative mental health of patients undergoing TKA may improve outcomes in this cohort.

Background Discharge to rehabilitation or a skilled nursing facility (SNF) after total joint arthroplasty remains a primary driver of cost excess for bundled payments. An accurate preoperative risk prediction tool would help providers and health systems identify and modulate perioperative care for higher risk individuals and serve as a vital tool in preoperative clinic as part of shared decision-making regarding the risks/benefits of surgery. Methods A total of 10,155 primary total knee (5,570, 55%) and hip (4,585, 45%) arthroplasties performed between June 2013 and January 2018 at a single institution were reviewed. The predictive ability of 45 variables for discharge location (SNF/rehab vs home) was tested, including preoperative sociodemographic factors, intraoperative metrics, postoperative labs, as well as 30 Elixhauser comorbidities. Parameters surviving selection were included in a multivariable logistic regression model, which was calibrated using 20,000 bootstrapped samples. Results A total of 1786 (17.6%) cases were discharged to a SNF/rehab, and a multivariable logistic regression model demonstrated excellent predictive accuracy (area under the receiver operator characteristic curve: 0.824) despite requiring only 9 preoperative variables: age, partner status, the American Society of Anesthesiologists score, body mass index, gender, neurologic disease, electrolyte disorder, paralysis, and pulmonary circulation disorder. Notably, this model was independent of surgery (knee vs hip). Internal validation showed no loss of accuracy (area under the receiver operator characteristic curve: 0.8216, mean squared error: 0.0004) after bias correction for overfitting, and the model was incorporated into a readily available, online prediction tool for easy clinical use. Conclusion This convenient, interactive tool for estimating likelihood of discharge to a SNF/rehab achieves excellent accuracy using exclusively preoperative factors. These should form the basis for improved reimbursement legislation adjusting for patient risk, ensuring no disparities in access arise for vulnerable populations. Level of Evidence III.

Background Periprosthetic joint infection (PJI) in total knee arthroplasty (TKA) is a challenging problem. The purpose of this study was to outline a novel technique to treat TKA PJI. We define 1.5-stage exchange arthroplasty as placing an articulating spacer with the intent to last for a prolonged time. Methods A retrospective review was performed from 2007 to 2019 to evaluate patients treated with 1.5-stage exchange arthroplasty for TKA PJI. Inclusion criteria included: articulating knee spacer(s) remaining in situ for 12 months and the patient deferring a second-stage reimplantation because the patient had acceptable function with the spacer (28 knees) or not being a surgical candidate (three knees). Thirty-one knees were included with a mean age of 63 years, mean BMI 34.4 kg/m2, 12 were female, with a mean clinical follow-up of 2.7 years. Cobalt-chrome femoral and polyethylene tibial components were used. We evaluated progression to second-stage reimplantation, reinfection, and radiographic outcomes. Results At a mean follow-up of 2.7 years, 25 initial spacers were in situ (81%). Five knees retained their spacer(s) for some time (mean 1.5 years) and then underwent a second-stage reimplantation; one of the five had progressive radiolucent lines but no evidence of component migration. Three knees (10%) had PJI reoccurrence. Four had progressive radiolucent lines, but there was no evidence of component migration in any knees. Conclusions 1.5-stage exchange arthroplasty may be a reasonable method to treat TKA PJI. At a mean follow-up of 2.7 years, there was an acceptable rate of infection recurrence and implant durability.

BACKGROUND: During the last 5 years, there has been an increase in the use of unicompartmental knee arthroplasty (UKA) to treat knee osteoarthritis in Australia, and these account for almost 6% of annual knee replacement procedures. However, there is debate as to whether a fixed bearing or a mobile bearing design is best for decreasing revision for loosening and disease progression as well as improving survivorship. Small sample sizes and possible confounding in the studies on the topic may have masked differences between fixed and mobile bearing designs. QUESTIONS/PURPOSES: Using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR), we selected the four contemporary designs of medial compartment UKA: mobile bearing, fixed modular, all-polyethylene, and fixed molded metal-backed used for the treatment of osteoarthritis to ask: (1) How do the different designs of unicompartmental knees compare with survivorship as measured by cumulative percentage revision (CPR)? (2) Is there a difference in the revision rate between designs as a function of patient sex or age? (3) Do the reasons for revision differ, and what types of revision procedures are performed when these UKA are revised? METHODS: The AOANJRR longitudinally maintains data on all primary and revision joint arthroplasties, with nearly 100% capture. The study population included all UKA procedures undertaken for osteoarthritis between September 1999 and December 2018. Of 56,628 unicompartmental knees recorded during the study period, 50,380 medial UKA procedures undertaken for osteoarthritis were included in the analysis after exclusion of procedures with unknown bearing types (31 of 56,628), lateral or patellofemoral compartment UKA procedures (5657 of 56,628), and those performed for a primary diagnosis other than osteoarthritis (560 of 56,628). There were 50,380 UKA procedures available for analysis. The study group consisted of 40% (20,208 of 50,380) mobile bearing UKA, 35% (17,822 of 50,380) fixed modular UKA, 23% (11,461 of 50,380) all-polyethylene UKA, and 2% (889 of 50,380) fixed molded metal-backed UKA. There were similar sex proportions and age distributions for each bearing group. The overall mean age of patients was 65 ± 9.4 years, and 55% (27,496 of 50,380) of patients were males. The outcome measure was the CPR, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the first revision. Hazard ratios from Cox proportional hazards models, adjusted for sex and age, were performed to compare the revision rates among groups. The cohort was stratified into age groups of younger than 65 years and 65 years and older to compare revision rates as a function of age. Differences among bearing groups for the major causes and modes of revision were assessed using hazard ratios. RESULTS: At 15 years, fixed modular UKA had a CPR of 16% (95% CI 15% to 17%). In comparison, the CPR was 23% (95% CI 22% to 24%) for mobile bearing UKA, 26% (95% CI 24% to 27%) for all-polyethylene UKA, and 20% (95% CI 16% to 24%) for fixed molded metal-backed UKA. The lower revision rate for fixed modular UKA was seen through the entire period compared with mobile bearing UKA (hazard ratio 1.5 [95% CI 1.4 to 1.6]; p < 0.001) and fixed molded metal-backed UKA (HR 1.3 [95% CI 1.1 to 1.6]; p = 0.003), but it varied with time compared with all-polyethylene UKA. The findings were consistent when stratified by sex or age. Although all-polyethylene UKA had the highest revision rate overall and for patients younger than 65 years, for patients aged 65 years and older, there was no difference between all-polyethylene and mobile bearing UKA. When compared with fixed modular UKA, a higher revision risk for loosening was shown in both mobile bearing UKA (HR 1.7 [95% CI 1.5 to 1.9]; p < 0.001) and all-polyethylene UKA (HR 2.4 [95% CI 2.1 to 2.7]; p < 0.001). The revision risk for disease progression was higher for all-polyethylene UKA at all time points (HR 1.4 [95% CI 1.3 to 1.6]; p < 0.001) and for mobile bearing UKA after 8 years when each were compared with fixed modular UKA (8 to 12 years: HR 1.4 [95% CI 1.2 to 1.7]; p < 0.001; 12 or more years: HR 1.9 [95% CI 1.5 to 2.3]; p < 0.001). The risk of revision to TKA was higher for mobile bearing UKA compared with fixed modular UKA (HR 1.4 [95% CI 1.3 to 1.5]; p < 0.001). CONCLUSION: If UKA is to be considered for the treatment of isolated medial compartment osteoarthritis, the fixed modular UKA bearing has the best survivorship of the current UKA designs. LEVEL OF EVIDENCE: Level III, therapeutic study.

There are few well-powered studies investigating the association of Paget's disease of bone on patients undergoing primary total hip arthroplasty (THA). This study utilized a nationwide database to determine whether Paget's patients undergoing primary THA are associated with higher rates of (1) lengths of stay (LOS); (2) costs; and (3) complications (medical/surgical and implant-related).Using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes, Paget's patients undergoing primary THA were identified and matched to non-Paget's patients in a 1:5 ratio by age, sex, and comorbidities utilizing the PearlDiver database. This resulted in 21,714 patients in Paget's (n = 3619) and non-Paget's (n = 18,095) cohorts. Outcomes assessed included LOS, episode-of-care costs, medical/surgical complications, and implant-related complications. A P value less than .003 was considered statistically significant.Compared to the matched cohort, Paget's patients undergoing primary THA had significantly longer LOS (P.0001), higher 90-day total global episode-of-care costs (P.0001), higher 90-day medical and surgical complications (P.0001), and higher implant-related complications (P.0001).We found that Paget's was associated with higher rates of LOS, costs, and complications. Although there was an association found, the risk appears reasonably low compared to the matched cohort. The study can be utilized by orthopedic professionals to counsel and educate these patients of potential complications which may occur following their procedure.

There are few studies evaluating total knee arthroplasty (TKA) in patients with dementia. The purpose of this study was to evaluate the rate of revision, complication, emergency department (ED) visitation, and discharge disposition in patients with dementia undergoing primary TKA. In this retrospective study, we evaluated patients from 2007 to 2017 using a national database. Ninety-day complications in patients with dementia undergoing TKA were increased risk of ED visitation and skilled nursing facility (SNF) disposition (p ≤ 0.05). Two-year complications in patients with dementia undergoing TKA were increased risk of ED visitation and SNF disposition (p ≤ 0.05). Patients with dementia undergoing TKA are at an increased risk of resource utilization.

BACKGROUND: Perioperative neurocognitive disorders (PND) are common complications in older adults associated with increased 1-year mortality and long-term cognitive decline. One risk factor for worsened long-term postoperative cognitive trajectory is the Alzheimer’s Disease (AD) genetic risk factor APOE4. APOE4 is thought to elevate AD risk partly by increasing neuroinflammation, which is also a theorized mechanism for PND. Yet, it is unclear whether modulating apoE4 protein signaling in older surgical patients would reduce PND risk or severity. OBJECTIVES: MARBLE is a randomized, blinded, placebo-controlled phase II sequential dose escalation trial designed to evaluate perioperative administration of an apoE mimetic peptide drug, CN-105, in older adults (age ≥60 years). The primary aim is evaluating the safety of CN-105 administration, as measured by adverse event (AE) rates in CN-105 versus placebo-treated patients. Secondary aims include assessing perioperative CN-105 administration feasibility and its efficacy for reducing postoperative neuroinflammation and PND severity. METHODS: 201 patients undergoing non-cardiac, non-neurological surgery will be randomized to control or CN-105 treatment groups and receive drug or placebo before and every six hours after surgery, for up to three days after surgery. Chart reviews, pre- and postoperative cognitive testing, delirium screening, and blood and CSF analyses will be performed to examine effects of CN-105 on perioperative adverse event rates, cognition, and neuro-inflammation. Trial results will be disseminated by presentations at conferences and peer-reviewed publications. CONCLUSION: MARBLE is a transdisciplinary study designed to measure CN-105 safety and efficacy for preventing PND in older adults and to provide insight into the pathogenesis of these geriatric syndromes.

The use of genetic sequencing modalities in the diagnosis of periprosthetic joint infection (PJI) and the identification of organisms has gained popularity recently. Polymerase chain reaction (PCR) offers timely results for common organisms. The purpose of this study was to compare the accuracy of broad-range PCR, conventional culture, the Musculoskeletal Infection Society (MSIS) criteria, and the recently proposed criteria by Parvizi et al in the diagnosis of PJI. In this retrospective study, aspirate or tissue samples were collected in 104 revision and 86 primary arthroplasties for routine diagnostic workup for PJI and sent to the laboratory for PCR. Concordance along with statistical differences between diagnostic studies were calculated using chi-square test for categorical data. On comparison with the MSIS criteria, concordance was significantly lower for PCR at 64.7% compared with 86.3% for culture ( P P =.706) or sample collection method (tissue swab or synovial fluid) ( P =.316). Of the 87 patients who met MSIS criteria, only 20 (23.0%) PCR samples had an organism identified. In this series, PCR had little utility as a stand-alone test for the diagnosis of PJI, with a sensitivity of only 23.0% when using MSIS criteria as the gold standard. Polymerase chain reaction also appears to be significantly less accurate than culture in the diagnosis of PJI. Currently, several laboratory tests used for either criteria for PJI diagnosis should be obtained along with the overall clinical picture to help guide decision-making for PJI treatment. [ Orthopedics . 2020;43(6):333–338.]

Venous thromboembolism and ischemic stroke are major complications following total knee arthroplasty (TKA) and potentially are associated with a patent foramen ovale (PFO). Although this association has been shown in other surgical disciplines, it has not been demonstrated in patients undergoing TKA. This study was undertaken to determine whether patients with a PFO would have a significantly increased risk of cerebrovascular accident (CVA) following TKA. The Humana national database was used to identify TKA patients who were stratified by the presence of a PFO from 2007 to 2016. Ninety-day follow-up was used for the primary outcome of CVA. Potential confounding comorbidities also were investigated, including age, sex, anticoagulation, insurance type, arrhythmia, valvular disease, peripheral vascular disease, chronic kidney disease, and diabetes mellitus. Of 153,245 TKAs, a total of 2272 patients had strokes; 479 of these patients had a PFO. On multivariable analysis, PFO remained an independent predictor of CVA postoperatively (odds ratio, 3.824; 95% confidence interval, 2.614–5.406; P P =.0001 and odds ratio, 0.749; 95% confidence interval, 0.628–0.885; P =.0009, respectively). The findings of the multivariable analysis indicate PFO is associated with early postoperative CVA within 90 days following TKA. If known preoperatively, appropriate referral should be made to a cardiologist for PFO management and anticoagulation to reduce the overall risk of stroke. [ Orthopedics . 2020;43(3):e151–e158.]

Evaluating the severity of knee osteoarthritis (OA) accounts for significant plain film workload and is a crucial component of knee radiograph interpretation, which informs surgical decision-making for costly and invasive procedures such as knee replacement. The Kellgren-Lawrence (KL) grading scale systematically and quantitatively assesses the severity of knee OA but is associated with notable inter-reader variability. In this study, we propose a deep learning method for the assessment of joint space narrowing (JSN) in the knee, which is an essential part of determining the KL grade. To determine the extent of JSN, we analyzed 99 knee radiographs to calculate the distance between the femur and tibia. Our algorithm's measurements of JSN and KL grade correlated well other radiologists' assessments. The average distance (in pixels) between the femur and tibia bones as measured by our algorithm was 9.60 for KL=0, 7.60 for KL=1, 6.89 for KL=2, 3.75 for KL=3, 1.25 for KL=4. Additionally, we used 100 manually annotated knee radiographs to train the algorithm to segment the femur and tibia bones. When evaluated on an independent set of 20 knee radiographs, the algorithm demonstrated a Dice coefficient of 96.59%. An algorithm for measurement of JSN and KL grades may play a significant role in automatically, reliably, and passively evaluating knee OA severity and influence and surgical decision-making and treatment pathways.