The contribution of neutrophils to bacteriophage clearance and pharmacokinetics in vivo.

With the increasing prevalence of antimicrobial-resistant bacterial infections, there is interest in using bacteriophages (phages) to treat such infections. However, the factors that govern bacteriophage pharmacokinetics in vivo remain poorly understood. Here, we have examined the contribution of neutrophils, the most abundant phagocytes in the body, to the pharmacokinetics of i.v. administered bacteriophage in uninfected mice. A single dose of LPS-5, a bacteriophage recently used in human clinical trials to treat drug-resistant Pseudomonas aeruginosa, was administered i.v. to both immunocompetent BALB/c and neutropenic CD1 mice. Phage concentrations were assessed in peripheral blood and spleen at 0.25, 1, 2, 4, 8, 12, and 24 hours after administration by plaque assay and qPCR. We observed that the phage clearance was only minimally affected by neutropenia. Indeed, the half-lives of phages in blood in BALB/c and CD1 mice were 3.45 and 3.66 hours, respectively. These data suggest that neutrophil-mediated phagocytosis is not a major determinant of phage clearance. Conversely, we observed a substantial discrepancy in circulating phage levels over time when measured by qPCR versus plaque assay, suggesting that significant inactivation of circulating phages occurs over time. These data indicate that alternative factors, but not neutrophils, inactivate i.v. administered phages.

Current Use of Patient-Reported Outcome Measures Ignores Functional Demand.

INTRODUCTION: Patient-reported outcome measures (PROMs) are used in orthopaedic surgery to measure aspects of musculoskeletal function that are important to patients, such as disability and pain. However, current assessments of function using PROMs do not necessarily consider a patient's functional demands in detail. A patient's functional demands could serve as a confounder to their perception of their functional ability. Hence, functional demands may need to be adjusted for when PROMs are used to measure musculoskeletal function. METHODS: We conducted a cross-sectional study in which new orthopaedic patients completed a questionnaire regarding demographics, function [Patient-Reported Outcomes Measurement Information System], functional demand (Tegner Activity Level Scale), pain self-efficacy, and symptoms of depression. 169 eligible patients with diverse orthopaedic conditions were enrolled in the study from an orthopaedic clinic, and 19 were excluded for incomplete questionnaires. RESULTS: The mean Patient-Reported Outcomes Measurement Information System score was 36.5 ± 9.1, and the mean Tegner score was 2.6 ± 2.0. In the multivariable regression model, patient-reported function was significantly associated with functional demand (ß = 0.17, P < 0.001). Significant associations were observed for pain self-efficacy (ß = 0.15, P < 0.001), acuity (ß = -0.10, P = 0.004), and age 80 years or older (ß = -0.16, P = 0.004). No notable association was observed with depression or age 65 to 79 years. DISCUSSION: Higher patient-reported physical function is associated with higher levels of functional demand when controlling for psychosocial factors, acuity, and age. Because of its confounding effect on measuring physical function, functional demand should be assessed and included in models using PROMs before and after surgery. For example, payment models using improvements in PROMs, such as the short form of the Hip dysfunction and Osteoarthritis Outcome Score and the Knee injury and Osteoarthritis Outcome Score after joint arthroplasty, should include functional demand in the model when assessing quality of care. LEVEL OF EVIDENCE: Level II.

Performing region-specific tasks does not improve lower extremity patient-reported outcome scores.

BACKGROUND: Patient-reported outcome measures quantify outcomes from patients' perspective with validated instruments. QuickDASH (Quick Disability of Arm, Shoulder and Hand, an upper extremity PROM) scores improve after completing instrument tasks, suggesting patient-reported outcome results can be modified. We hypothesized that performing lower extremity tasks on the knee injury and osteoarthritis outcome score for joint reconstruction (KOOS-JR) and hip disability and osteoarthritis outcome score for joint reconstruction (HOOS-JR) instruments would similarly improve the scores. METHODS: Forty seven hip and 62 knee osteoarthritis patients presenting to a suburban academic center outpatient osteoarthritis and joint replacement clinic were enrolled and randomized to an intervention or a control group. Inclusion criteria were age over 18 years and English competency. Patients completed a HOOS-JR or KOOS-JR instrument, completed tasks similar to those of the instrument (intervention) or the QuickDASH (control), and then repeated instruments again. Paired and unpaired t-tests were used to compare the intervention and control group scores before and after tasks. RESULTS: There was no significant difference in total or individual scores after task completion compared to baseline in either the HOOS-JR or the KOOS-JR groups. There was no significant difference in the scores between the intervention or control groups. CONCLUSIONS: Disability may be less modifiable in the lower extremity than in the upper extremity, perhaps because upper extremity activities are more easily compensated by the contralateral limb, or because lower extremity activities are more frequent. Thorough evaluation of factors influencing patient-reported outcome measures is necessary before their extensive application to quality control and reimbursement models.

Remote Summer Research Program to Improve Opportunity and Mentorship for Underrepresented Students With Interest in Orthopaedic Surgery: 3-Year Experiences.

INTRODUCTION: Medical students are challenged with a limited number of research opportunities to help prepare for an exceptionally competitive process for matching in an orthopaedic residency. The aim of this study was to assess the 3-year experience of our 8 to 10-week remote summer research program in support of underrepresented students with an interest in orthopaedic surgery. METHODS: We received over 500 applications, and a total of 37 students (7.4%) participated in the program over the past 3 years. A total of 14 faculty mentors were matched with 1 or 2 students each. The research program delivered a curriculum including (1) research-related topics led by a content expert; (2) weekly faculty lectures discussing topics including orthopaedic conditions, diversity in orthopaedics, leadership, and work-life balance; and (3) a minimum of 8 weeks of mentorship experience with an assigned faculty and a peer mentor. Students and faculty were surveyed to measure skill progression, research productivity, and program satisfaction. RESULTS: Program participants represented a range of race/ethnic backgrounds and research experience levels. The cohort included a high rate of female (51%) and Black (35%) participants relative to representation of these groups in orthopaedic surgery. Postprogram surveys indicated that all participants improved their research skills, orthopaedic interest, and mentorship/networking skills. Most students (89%) stated that they were adequately matched to their faculty mentor. Most students (79%) indicated that they contributed to either manuscript or conference abstract as coauthors. DISCUSSION: The study findings suggest improved research skills, interest, and confidence to pursue orthopaedic residency and mentorship/networks in the field. Our long-term vision is to improve the accessibility and quality of mentorship for underrepresented students to foster an equitable pathway into the field of orthopaedic surgery.

Opioid Use After Robotic-Assisted Versus Conventional Total Hip Arthroplasty: A National Database Analysis.

BACKGROUND: In this study, we tested the null hypothesis that robotic-assisted total hip arthroplasty (THA) vs conventional THA was not associated with (1) the amount of postoperative opioid use and (2) the incidence of new, persistent opioid use. MATERIALS AND METHODS: We used a large, national administrative database to identify patients 50 years and older undergoing primary robotic or conventional THA. Patients with hip fractures or a history of malignancy, hip infection, or opioid use disorder were excluded. Patients who filled an opioid prescription within 1 year to 30 days preoperatively or who underwent a subsequent procedure within 1 year after THA were excluded. Outcomes included the morphine milligram equivalents (MMEs) filled within the THA perioperative period and the incidence of new, persistent opioid use. Multivariable logistic regression models were used to evaluate associations between robotic-assisted THA and new, persistent opioid use, adjusting for age, sex, insurance plan, region, location of surgery, and comorbidities. RESULTS: In the postoperative period, robotic-assisted THA, compared with conventional THA, was associated with a lower mean total MMEs filled per patient (452.2 vs 517.1; P<.001) and a lower mean MMEs per patient per day (71.53 vs 74.64; P<.001). Patients undergoing robotic-assisted THA had decreased odds of developing new, persistent opioid use compared with patients undergoing conventional THA (adjusted odds ratio, 0.82 [95% CI, 0.74-0.90]). CONCLUSION: Robotic-assisted THA is associated with lower postoperative opioid use and a decreased odds of developing new, persistent opioid use compared with conventional THA. For the purposes of reducing opioid use, our results support the adoption of robotic-assisted THA. [Orthopedics. 2024;47(5):289-294.].

Health Numeracy Is Associated With a Patient's Ability to Interpret Patient-Reported Outcome Measures Data.

BACKGROUND: Patient-reported outcome measures (PROMs) were originally developed as research tools; however, there is increasing interest in using PROMs to inform clinical care. Prior work has shown the benefits of implementing PROMs at the point of care, but a patient's health numeracy (their ability to understand and work with numbers) may affect their ability to interpret PROM results. MATERIALS AND METHODS: We recruited patients presenting to an outpatient orthopedic clinic. Forty-nine patients completed a survey that included demographic information, the short-form General Health Numeracy Test, and accuracy questions about four PROM displays (bar graph, table, line graph, pictograph) that indicated the same PROM results. RESULTS: Patients with higher health numeracy answered all display accuracy questions correctly (P=.016). Patients who preferred using the table were more likely to answer display accuracy questions incorrectly (odds ratio, 0.013, P=.024). The two most frequently preferred PROM formats were bar graphs and tables, and most patients preferred to learn about their PROM function scores via a combination of displays and verbal discussions. CONCLUSION: Patient health numeracy is associated with the ability to correctly interpret visual displays of PROMs. Implementation of PROMs at point of care currently does not account for health numeracy. Efforts to account for health numeracy when using PROMs at point of care may improve the efficacy of using PROMs to improve outcomes in orthopedic surgery. [Orthopedics. 2024;47(5):e255-e260.].

The Influence of an Unexpected Symbolic Gift on Postoperative Arthroplasty Patients' Press Ganey Scores.

BACKGROUND: Hospitals use Press Ganey surveys to evaluate patient satisfaction. The goal of our study was to evaluate whether surgeon-driven gifting to patients postoperatively affects Press Ganey Survey responses. METHODS: There were 1,468 patients undergoing arthroplasty at our institution who were randomized to receive a thank-you gift, a small bouquet of flowers, and a note from their provider after surgery, or nothing for completing their preoperative arthroplasty registry questionnaire. Press Ganey surveys were sent to patients who received and did not receive flowers immediately after their hospital stay and after the patients' first postoperative visit. Scores were reported as the mean score and the fraction of responses with a top-box rating. One-sided student t-tests and Fisher's exact tests were used to assess statistical significance. RESULTS: Hospital Discharge: Patients who received flowers had higher Press Ganey survey scores than patients who did not receive flowers. For example, for "physician's concerns for questions," they had higher scores (mean difference: 3.7 ± 1.6 points, P = .012) and a 9% higher top-box rating (P = .032). For "staff attitude toward visitors," they also had higher scores (mean difference: 2.8 ± 1.3 points, P = .019) and a 7% higher top-box rating (P = .049). First Follow-up: Patients who received flowers had a higher top-box rating for "concern provider showed for questions" and "amount of time provider spent with you" by 6% (P = .046) and 11% (P = .009), respectively. They also had higher scores for "information provider gave about medications" (mean difference: 4.0 ± 1.6 points, P = .009) and 11% higher top-box rating (P = .006). CONCLUSIONS: Press Ganey Surveys were higher in orthopaedic patients who received bouquets of flowers from their arthroplasty surgeons compared to patients who did not. At follow-up, improved Press Ganey scores persisted if the patient received flowers. The gift of flowers generates patient loyalty to their surgeon.

Pain Self-Efficacy Can Improve During a Visit With an Orthopedic Surgeon.

BACKGROUND: Greater pain self-efficacy (PSE) is associated with reduced pain, fewer limitations, and increased quality of life after treatment for orthopedic conditions. The aims of this study were to (1) assess if PSE improves during a visit with an orthopedic surgeon and (2) identify modifiable visit factors that are associated with an increase in PSE. MATERIALS AND METHODS: We performed a prospective observational study of orthopedic clinic visits at a multispecialty clinic from February to May 2022. New patients who presented to one of six orthopedic surgeons were approached for the study. Patients who provided consent completed a pre-visit questionnaire including the Pain Self-Efficacy Questionnaire (PSEQ) and demographic questions. A trained research member recorded the five-item Observing Patient Involvement in Decision Making Instrument (OPTION-5) score, number of questions asked, and visit duration. Immediately after the visit, patients completed a post-visit questionnaire consisting of the PSEQ and Perceived Involvement in Care Scale (PICS). RESULTS: Of 132 patients enrolled, 61 (46%) had improved PSE after the orthopedic visit, with 38 (29%) having improvement above a clinically significant threshold. There were no significant differences between patients with increased PSE and those without increased PSE when comparing the PICS, OPTION-5, questions asked, or visit duration. CONCLUSION: Almost half of the patients had improvement in PSE during an orthopedic visit. The causal pathway to how to improve PSE and the durability of the improved PSE have implications in strategies to improve patient outcomes in orthopedic surgery, such as communication methods and shared decision-making. Future research can focus on studying different interventions that facilitate improving PSE. [Orthopedics. 2024;47(4):e197-e203.].

No differences in outcomes with stopping or continuing antibiotic suppression in periprosthetic joint infections.

The data on long-term antibiotic use following debridement, antibiotics, and implant retention (DAIR) for treatment of periprosthetic joint infections are limited. In this single-center retrospective study, we show that patients with eventual cessation of antibiotic suppression after DAIR had similar outcomes to those who remained on chronic antibiotic suppression.

A balance focused biometric does not predict rehabilitation needs and outcomes following total knee arthroplasty.

BACKGROUND: Both length of hospital stay and discharge to a skilled nursing facility are key drivers of total knee arthroplasty (TKA)-associated spending. Identifying patients who require increased postoperative care may improve expectation setting, discharge planning, and cost reduction. Balance deficits affect patients undergoing TKA and are critical to recovery. We aimed to assess whether a device that measures preoperative balance predicts patients' rehabilitation needs and outcomes after TKA. METHODS: 40 patients indicated for primary TKA were prospectively enrolled and followed for 12 months. Demographics, KOOS-JR, and PROMIS data were collected at baseline, 3-months, and 12-months. Single-leg balance and sway velocity were assessed preoperatively with a force plate (Sparta Science, Menlo Park, CA). The primary outcome was patients' discharge facility (home versus skilled nursing facility). Secondary outcomes included length of hospital stay, KOOS-JR scores, and PROMIS scores. RESULTS: The mean preoperative sway velocity for the operative leg was 5.7 ± 2.7 cm/s, which did not differ from that of the non-operative leg (5.7 ± 2.6 cm/s, p = 1.00). Five patients (13%) were discharged to a skilled nursing facility and the mean length of hospital stay was 2.8 ± 1.5 days. Sway velocity was not associated with discharge to a skilled nursing facility (odds ratio, OR = 0.82, 95% CI = 0.27-2.11, p = 0.690) or longer length of hospital stay (b = -0.03, SE = 0.10, p = 0.738). An increased sway velocity was associated with change in PROMIS items from baseline to 3 months for global07 ("How would you rate your pain on average?" b = 1.17, SE = 0.46, p = 0.015) and pain21 ("What is your level of pain right now?" b = 0.39, SE = 0.17, p = 0.025) at 3-months. CONCLUSION: Preoperative balance deficits were associated with postoperative improvements in pain and function after TKA, but a balance focused biometric that measured single-leg sway preoperatively did not predict discharge to a skilled nursing facility or length of hospital stay after TKA making their routine measurement cost-ineffective.

Prophages are Infrequently Associated With Antibiotic Resistance in Pseudomonas aeruginosa Clinical Isolates.

Antimicrobial resistance (AMR) is a significant obstacle to the treatment of bacterial infections, including in the context of Pseudomonas aeruginosa infections in patients with cystic fibrosis (CF). Lysogenic bacteriophages can integrate their genome into the bacterial chromosome and are known to promote genetic transfer between bacterial strains. However, the contribution of lysogenic phages to the incidence of AMR is poorly understood. Here, in a set of 187 clinical isolates of Pseudomonas aeruginosa collected from 82 patients with CF, we evaluate the links between prophages and both genomic and phenotypic resistance to five anti-pseudomonal antibiotics: tobramycin, colistin, ciprofloxacin, meropenem, aztreonam, and tazobactam. We find that P. aeruginosa isolates contain on average 3.06 +/-1.84 (SD) predicted prophages. We find no significant association between the number of prophages per isolate and the mean inhibitory concentration (MIC) for any of these antibiotics. We then investigate the relationship between particular prophages and AMR. We identify a single lysogenic phage that is associated with phenotypic resistance to the antibiotic tobramycin. Consistent with this association, we identify AMR genes associated with resistance to tobramycin in these strains and find that they are not encoded directly on prophage sequences. These findings suggest that prophages are infrequently associated with the AMR genes in clinical isolates of P. aeruginosa .

Optimized Dosing and Delivery of Bacteriophage Therapy for Wound Infections.

Lytic bacteriophages, viruses that lyse (kill) bacteria, hold great promise for treating infections, including wound infections caused by antimicrobial-resistant Pseudomonas aeruginosa. However, the optimal dosing and delivery strategies for phage therapy remain unclear. In a mouse wound infection model, we investigated the impact of dose, frequency, and administration route on the efficacy of phage therapy. We find that topical but not intravenous delivery is effective in this model. High-doses of phage reduces bacterial burden more effectively than low-doses, and repeated dosing achieves the highest eradication rates. Building on these insights, we developed "HydroPhage", a hyaluronan-based hydrogel system that uses dynamic covalent crosslinking to deliver high-titre phages over one week. HydroPhage eradicates infections five times more effectively than intravenous injection. We conclude that hydrogel-based sustained phage delivery enhances the efficacy of phage therapy and offers a practical, well-tolerated option for topical application.

The outcome of revision total hip arthroplasty for instability.

Aims: Instability is a common indication for revision total hip arthroplasty (THA). However, even after the initial revision, some patients continue to have recurrent dislocation. The aim of this study was to assess the risk for recurrent dislocation after revision THA for instability. Methods: Between 2009 and 2019, 163 patients underwent revision THA for instability at Stanford University Medical Center. Of these, 33 (20.2%) required re-revision due to recurrent dislocation. Cox proportional hazard models, with death and re-revision surgery for periprosthetic infection as competing events, were used to analyze the risk factors, including the size and alignment of the components. Paired t-tests or Wilcoxon signed-rank tests were used to assess the outcome using the Veterans RAND 12 (VR-12) physical and VR-12 mental scores, the Harris Hip Score (HHS) pain and function, and the Hip disability and Osteoarthritis Outcome score for Joint Replacement (HOOS, JR). Results: The median follow-up was 3.1 years (interquartile range 2.0 to 5.1). The one-year cumulative incidence of recurrent dislocation after revision was 8.7%, which increased to 18.8% at five years and 31.9% at ten years postoperatively. In multivariable analysis, a high American Society of Anesthesiologists (ASA) grade (hazard ratio (HR) 2.72 (95% confidence interval (CI) 1.13 to 6.60)), BMI between 25 and 30 kg/m2 (HR 4.31 (95% CI 1.52 to 12.27)), the use of specialized liners (HR 5.39 (95% CI 1.97 to 14.79) to 10.55 (95% CI 2.27 to 49.15)), lumbopelvic stiffness (HR 6.03 (95% CI 1.80 to 20.23)), and postoperative abductor weakness (HR 7.48 (95% CI 2.34 to 23.91)) were significant risk factors for recurrent dislocation. Increasing the size of the acetabular component by > 1 mm significantly decreased the risk of dislocation (HR 0.89 (95% CI 0.82 to 0.96)). The VR-12 physical and HHS (pain and function) scores improved significantly at mid term. Conclusion: Patients requiring revision THA for instability are at risk of recurrent dislocation. Higher ASA grades, being overweight, a previous lumbopelvic fusion, the use of specialized liners, and postoperative abductor weakness are significant risk factors.

Detecting contamination events during robotic total joint arthroplasty.

BACKGROUND: Robot-assisted total joint arthroplasty (robotic-TJA) has become more widespread over the last 20 years due to higher patient satisfaction and reduced complications. However, robotic TJA may have longer operative times and increased operating room traffic, which are known risk factors for contamination events. Contamination of surgical instruments may be contact- or airborne-related with documented scalpel blade contamination rates up to 9%. The robot arm is a novel instrument that comes in and out of the surgical field, so our objective was to assess whether the robot arm is a source of contamination when used in robotic TJA compared to other surgical instruments. METHODS: This was a prospective, single-institution, single-surgeon pilot study involving 103 robotic TJAs. The robot arm was swabbed prior to incision and after closure. Pre- and postoperative control swabs were also collected from the suction tip and scalpel blade. Swabs were incubated for 24 hours on tryptic soy agar followed by inspection for growth of any contaminating bacteria. RESULTS: A contamination event was detected in 10 cases (10%). The scalpel blade was the most common site of contamination (8%) followed by the robot arm (2%) and suction tip (0%). DISCUSSION: Robotic TJA is contaminated with bacteria at a rate around 10%. Although the robot arm is an additional source of potential contamination, the robot arm accrues bacterial contamination infrequently compared to the scalpel blade. CONCLUSION: Contamination of the robot arm during robotic TJA is minimal when compared to contamination of the scalpel blade.

An Inclusive Analysis of Racial and Ethnic Disparities in Orthopedic Surgery Outcomes.

BACKGROUND: Despite increasing attention, disparities in outcomes for Black and Hispanic patients undergoing orthopedic surgery are widening. In other racial-ethnic minority groups, outcomes often go unreported. We sought to quantify disparities in surgical outcomes among Asian, American Indian or Alaskan Native, and Native Hawaiian or Pacific Islander patients across multiple orthopedic subspecialties. MATERIALS AND METHODS: The National Surgical Quality Improvement Program was queried to identify all surgical procedures performed by an orthopedic surgeon from 2014 to 2020. Multivariable logistic regression models were used to investigate the impact of race and ethnicity on 30-day medical complications, readmission, reoperation, and mortality, while adjusting for orthopedic subspecialty and patient characteristics. RESULTS: Across 1,512,480 orthopedic procedures, all patients who were not White were less likely to have arthroplasty-related procedures (P<.001), and Hispanic, Asian, and American Indian or Alaskan Native patients were more likely to have trauma-related procedures (P<.001). American Indian or Alaskan Native (adjusted odds ratio [AOR], 1.005; 95% CI, 1.001-1.009; P=.011) and Native Hawaiian or Pacific Islander (AOR, 1.009; 95% CI, 1.005-1.014; P<.001) patients had higher odds of major medical complications compared with White patients. American Indian or Alaskan Native patients had higher risk of reoperation (AOR, 1.005; 95% CI, 1.002-1.008; P=.002) and Native Hawaiian or Pacific Islander patients had higher odds of mortality (AOR, 1.003; 95% CI, 1.000-1.005; P=.019) compared with White patients. CONCLUSION: Disparities regarding surgical outcome and utilization rates persist across orthopedic surgery. American Indian or Alaskan Native and Native Hawaiian or Pacific Islander patients, who are under-represented in research, have lower rates of arthroplasty but higher odds of medical complication, reoperation, and mortality. This study highlights the importance of including these patients in orthopedic research to affect policy-related discussions. [Orthopedics. 2024;47(3):e131-e138.].

The PJI-TNM classification for periprosthetic joint infections.

Aims: This study aimed to evaluate the clinical application of the PJI-TNM classification for periprosthetic joint infection (PJI) by determining intraobserver and interobserver reliability. To facilitate its use in clinical practice, an educational app was subsequently developed and evaluated. Methods: A total of ten orthopaedic surgeons classified 20 cases of PJI based on the PJI-TNM classification. Subsequently, the classification was re-evaluated using the PJI-TNM app. Classification accuracy was calculated separately for each subcategory (reinfection, tissue and implant condition, non-human cells, and morbidity of the patient). Fleiss' kappa and Cohen's kappa were calculated for interobserver and intraobserver reliability, respectively. Results: Overall, interobserver and intraobserver agreements were substantial across the 20 classified cases. Analyses for the variable 'reinfection' revealed an almost perfect interobserver and intraobserver agreement with a classification accuracy of 94.8%. The category 'tissue and implant conditions' showed moderate interobserver and substantial intraobserver reliability, while the classification accuracy was 70.8%. For 'non-human cells,' accuracy was 81.0% and interobserver agreement was moderate with an almost perfect intraobserver reliability. The classification accuracy of the variable 'morbidity of the patient' reached 73.5% with a moderate interobserver agreement, whereas the intraobserver agreement was substantial. The application of the app yielded comparable results across all subgroups. Conclusion: The PJI-TNM classification system captures the heterogeneity of PJI and can be applied with substantial inter- and intraobserver reliability. The PJI-TNM educational app aims to facilitate application in clinical practice. A major limitation was the correct assessment of the implant situation. To eliminate this, a re-evaluation according to intraoperative findings is strongly recommended.

Is There Variation in Time to and Type of Treatment for Hip Osteoarthritis Based on Insurance?

BACKGROUND: Disparities in care access based on insurance exist for total hip arthroplasty (THA), but it is unclear if these lead to longer times to surgery. We evaluated whether rates of THA versus nonoperative interventions (NOI) and time to THA from initial hip osteoarthritis (OA) diagnosis vary by insurance type. METHODS: Using a national claims database, patients who had hip OA undergoing THA or NOI from 2011 to 2019 were identified and divided by insurance type: Medicaid-managed care; Medicare Advantage; and commercial insurance. The primary outcome was THA incidence within 3 years after hip OA diagnosis. Multivariable logistic regression models were created to assess the association between THA and insurance type, adjusting for age, sex, region, and comorbidities. RESULTS: Medicaid patients had lower rates of THA within 3 years of initial diagnosis (7.4 versus 10.9 or 12.0%, respectively; P < .0001) and longer times to surgery (297 versus 215 or 261 days, respectively; P < .0001) compared to Medicare Advantage and commercially-insured patients. In multivariable analyses, Medicaid patients were also less likely to receive THA (odds ratio (OR) = 0.62 [95% confidence intervals (CI): 0.60 to 0.64] versus Medicare Advantage, OR = 0.63 [95% CI: 0.61 to 0.64] versus commercial) or NOI (OR = 0.92 [95% CI: 0.91 to 0.94] versus Medicare Advantage, OR = 0.81 [95% CI: 0.79 to 0.82] versus commercial). CONCLUSIONS: Medicaid patients experienced lower rates of and longer times to THA than Medicare Advantage or commercially-insured patients. Further investigation into causes of these disparities, such as costs or access barriers, is necessary to ensure equitable care.

Host and microbial characteristics associated with recurrent prosthetic joint infections.

Approximately 20% of patients after resection arthroplasty and antibiotic spacer placement for prosthetic joint infection develop repeat infections, requiring an additional antibiotic spacer before definitive reimplantation. The host and bacterial characteristics associated with the development of recurrent infection is poorly understood. A case-control study was conducted for 106 patients with intention to treat by two-stage revision arthroplasty for prosthetic joint infection at a single institution between 2009 and 2020. Infection was defined according to the 2018 Musculoskeletal Infection Society criteria. Thirty-nine cases ("recurrent-periprosthetic joint infection [PJI]") received at least two antibiotic spacers before clinical resolution of their infection, and 67 controls ("single-PJI") received a single antibiotic cement spacer before infection-free prosthesis reimplantation. Patient demographics, McPherson host grade, and culture results including antibiotic susceptibilities were compared. Fifty-two (78%) single-PJI and 32 (82%) recurrent-PJI patients had positive intraoperative cultures at the time of their initial spacer procedure. The odds of polymicrobial infections were 11-fold higher among recurrent-PJI patients, and the odds of significant systemic compromise (McPherson host-grade C) were more than double. Recurrent-PJI patients were significantly more likely to harbor Staphylococcus aureus. We found no differences between cases and controls in pathogen resistance to the six most tested antibiotics. Among recurrent-PJI patients, erythromycin-resistant infections were more prevalent at the final than initial spacer, despite no erythromycin exposure. Our findings suggest that McPherson host grade, polymicrobial infection, and S. aureus infection are key indicators of secondary or persistent joint infection following resection arthroplasty and antibiotic spacer placement, while bacterial resistance does not predict infection-related arthroplasty failure.

Costs and Outcomes of Total Joint Arthroplasty in Medicare Beneficiaries Are Not Meaningfully Associated with Industry Payments.

BACKGROUND: Prior studies have demonstrated that industry payments affect physician prescribing patterns, but their effect on orthopaedic surgical costs is unknown. This study examines the relationship between industry payments and the total costs of primary total joint arthroplasty, as well as operating room cost, length of stay, 30-day mortality, and 30-day readmission. METHODS: Open Payments data were matched across a 20% sample of Medicare-insured patients undergoing primary elective total hip arthroplasty (THA) (n = 130,872) performed by 7,539 surgeons or primary elective total knee arthroplasty (TKA) (n = 230,856) performed by 8,977 surgeons from 2013 to 2015. Patient, hospital, and surgeon-specific factors were gathered. Total and operating room costs, length of stay, mortality, and readmissions were recorded. Multivariable linear and logistic regression models were used to identify the risk-adjusted relationships between industry payments and the primary and secondary outcomes. RESULTS: In this study, 96.7% of THA surgeons and 97.4% of TKA surgeons received industry payments. After multivariable risk adjustment, for each $1,000 increase in industry payments, the total costs of THA increased by $0.50 (0.003% of total costs) and the operating room costs of THA increased by $0.20 (0.003% of total costs). Industry payments were not associated with TKA cost. Industry payments were not associated with 30-day mortality after either THA or TKA. Higher industry payments were independently associated with a marginal decrease in the length of stay for patients undergoing THA (0.0045 days per $1,000) or TKA (0.0035 days per $1,000) and a <0.1% increase in the odds of 30-day readmission after THA for every $1,000 in industry payments. The median total THA costs were $300 higher (p < 0.001), whereas the median TKA costs were $150 lower (p < 0.001), for surgeons receiving the highest 5% of industry payments. These surgical procedures were more often performed in large urban areas, in hospitals with a higher number of beds, with a higher wage index, and by more experienced surgeons and were associated with a 0.4 to 1-day shorter length of stay (p < 0.001). CONCLUSIONS: Although most arthroplasty surgeons received industry payments, a minority of surgeons received the majority of payments. Overall, arthroplasty costs and outcomes were not meaningfully impacted by industry relationships. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Arthroplasty for femoral neck fractures is at risk for under restoration of lateral femoral offset.

PURPOSE: The aim of the study was to determine the restoration of hip biomechanics through lateral offset, leg length, and acetabular component position when comparing non-arthroplasty surgeons (NAS) to elective arthroplasty surgeons (EAS). METHODS: 131 patients, with a femoral neck fracture treated with a THA by 7 EAS and 20 NAS, were retrospectively reviewed. 2 blinded observers measured leg-length discrepancy, femoral offset, and acetabular component position. Multivariate logistic regression models examined the association between the surgeon groups and restoration of lateral femoral, acetabular offset, leg length discrepancy, acetabular anteversion, acetabular position, and component size, while adjusting for surgical approach and spinal pathology. RESULTS: NAS under-restored 4.8 mm of lateral femoral offset (43.9 ± 8.7 mm) after THA when compared to the uninjured side (48.7 ± 7.1 mm, p = 0.044). NAS were at risk for under-restoring lateral femoral offset when compared to EAS (p = 0.040). There was no association between lateral acetabular offset, leg length, acetabular position, or component size and surgeon type. CONCLUSIONS: Lateral femoral offset is at risk for under-restoration after THA for femoral neck fractures, when performed by surgeons that do not regularly perform elective THA. This indicates that lateral femoral offset is an under-appreciated contributor to hip instability when performing THA for a femoral neck fracture. Lateral femoral offset deserves as much attention and awareness as acetabular component position since a secondary analysis of our data reveal that preoperative templating and intraoperative imaging did not prevent under-restoration.