Clinical outcomes and return to dance after total hip arthroplasty or hip resurfacing in professional dancers.

Aims: Professional dancers represent a unique patient population in the setting of hip arthroplasty, given the high degree of hip strength and mobility required by their profession. We sought to determine the clinical outcomes and ability to return to professional dance after total hip arthroplasty (THA) or hip resurfacing arthroplasty (HRA). Methods: Active professional dancers who underwent primary THA or HRA at a single institution with minimum one-year follow-up were included in the study. Primary outcomes included the rate of return to professional dance, three patient-reported outcome measures (PROMs) (modified Harris Hip Score (mHHS), Hip disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS-JR), and Lower Extremity Activity Scale (LEAS)), and postoperative complications. Results: A total of 49 hips in 39 patients (mean age 56 years (SD 13); 80% female (n = 39)) were included. Mean follow-up was 4.9 years (SD 5.1). Of these 49 hips, 37 THAs and 12 HRAs were performed. In all, 96% of hips returned to professional dance activities postoperatively. With regard to PROMs, there were statistically significant improvements in mHHS, HOOS-JR, and LEAS from baseline to ≥ one year postoperatively. There were complications in 7/49 hips postoperatively (14%), five of which required revision surgery (10%). There were no revisions for instability after the index procedure. Two complications (5.4%) occurred in hips that underwent THA compared with five (42%) after HRA (p = 0.007), though the difference by procedure was not significantly different when including only contemporary implant designs (p = 0.334). Conclusion: Active professional dancers experienced significant improvements in functional outcome scores after THA or HRA, with a 96% rate of return to professional dance. However, the revision rate at short- to mid-term follow-up highlights the challenges of performing hip arthroplasty in this demanding patient population. Further investigation is required to determine the results of THA versus HRA using contemporary implant designs in these patients.

Association of Total Hip Arthroplasty Flexural Rigidity With Magnetic Resonance Imaging and Histological Findings.

BACKGROUND: Modular connections in total hip arthroplasty (THA) offer surgical advantages, but can contribute to implant fretting and corrosion due to micromotion at the head-stem interface. Previous studies implicated lower flexural rigidity as a key contributing factor to THA corrosion and fretting, but none associated flexural rigidity with direct histological evaluation or magnetic resonance imaging (MRI) outcomes. The purpose of this study was to determine how implant flexural rigidity is associated with MRI imaging metrics and histopathological outcomes in patients who have a failed THA. METHODS: Patients requiring revision THA surgery underwent preoperative MRIs with 3-dimensional multispectral imaging techniques to suppress metal artifacts. The MRI images were graded for adverse local tissue reactions. For each hip, trunnion flexural rigidity was measured from the retrieved femoral stem, and a periprosthetic tissue sample was retrieved and evaluated using semiquantitative histology. Generalized linear models and analyses of variance were used to assess associations between flexural rigidity and MRI and histology outcomes. RESULTS: A total of 106 THA stems were retrieved (46 women and 60 men, age: 68 years (range, 60 to 73 years). After adjustment for length of implantation, flexural rigidity was negatively correlated with histologic aseptic lymphocyte-dominant vasculitis-associated lesion severity (ß = -26.27, P = .018), Fujishiro lymphocyte grading (ß = -13.4, P = .039), perivascular lymphocyte layers (ß = -17.8, P = .022), the grade of tissue organization (ß = -22.5, P = .009), the presence of diffuse synovitis (ß = -66.5, P = .003), and the presence of lymphoid aggregates (ß = -75.9, P = .022). No association was found between MRI metrics and flexural rigidity. CONCLUSIONS: Among these implants, decreased trunnion stiffness was associated with increased histologic features of adverse host-mediated soft tissue reactions.

What Is the Role of a Periarticular Injection for Knee Arthroplasty Patients Receiving a Multimodal Analgesia Regimen Incorporating Adductor Canal and Infiltration Between the Popliteal Artery and Capsule of the Knee Blocks? A Randomized Blinded Placebo-Controlled Noninferiority Trial.

BACKGROUND: Optimal analgesic protocols for total knee arthroplasty (TKA) patients remain controversial. Multimodal analgesia is advocated, often including peripheral nerve blocks and/or periarticular injections (PAIs). If 2 blocks (adductor canal block [ACB] plus infiltration between the popliteal artery and capsule of the knee [IPACK]) are used, also performing PAI may not be necessary. This noninferiority trial hypothesized that TKA patients with ACB + IPACK + saline PAI (sham infiltration) would have pain scores that were no worse than those of patients with ACB + IPACK + active PAI with local anesthetic. METHODS: A multimodal analgesic protocol of spinal anesthesia, ACB and IPACK blocks, intraoperative ketamine and ketorolac, postoperative ketorolac followed by meloxicam, acetaminophen, duloxetine, and oral opioids was used. Patients undergoing primary unilateral TKA were randomized to receive either active PAI or control PAI. The active PAI included a deep injection, performed before cementation, of bupivacaine 0.25% with epinephrine, 30 mL; morphine; methylprednisolone; cefazolin; with normal saline to bring total volume to 64 mL. A superficial injection of 20 mL bupivacaine, 0.25%, was administered before closure. Control injections were normal saline injected with the same injection technique and volumes. The primary outcome was numeric rating scale pain with ambulation on postoperative day 1. A noninferiority margin of 1.0 was used. RESULTS: Ninety-four patients were randomized. NRS pain with ambulation at POD1 in the ACB + IPACK + saline PAI group was not found to be noninferior to that of the ACB + IPACK + active PAI group (difference = 0.3, 95% confidence interval [CI], [-0.9 to 1.5], P = .120). Pain scores at rest did not differ significantly among groups. No significant difference was observed in opioid consumption between groups. Cumulative oral morphine equivalents through postoperative day 2 were 89 ± 40 mg (mean ± standard deviation), saline PAI, vs 73 ± 52, active PAI, P = .1. No significant differences were observed for worst pain, fraction of time in severe pain, pain interference, side-effects (nausea, drowsiness, itching, dizziness), quality of recovery, satisfaction, length of stay, chronic pain, and orthopedic outcomes. CONCLUSIONS: For TKA patients given a comprehensive analgesic protocol, use of saline PAI did not demonstrate noninferiority compared to active PAI. Neither the primary nor any secondary outcomes demonstrated superiority for active PAI, however. As we cannot claim either technique to be better or worse, there remains flexibility for use of either technique.

Machine Learning on Medicare Claims Poorly Predicts the Individual Risk of 30-Day Unplanned Readmission After Total Joint Arthroplasty, Yet Uncovers Interesting Population-level Associations With Annual Procedure Volumes.

BACKGROUND: Unplanned hospital readmissions after total joint arthroplasty (TJA) represent potentially serious adverse events and remain a critical measure of hospital quality. Predicting the risk of readmission after TJA may provide patients and clinicians with valuable information for preoperative decision-making. QUESTIONS/PURPOSES: (1) Can nonlinear machine-learning models integrating preoperatively available patient, surgeon, hospital, and county-level information predict 30-day unplanned hospital readmissions in a large cohort of nationwide Medicare beneficiaries undergoing TJA? (2) Which predictors are the most important in predicting 30-day unplanned hospital readmissions? (3) What specific information regarding population-level associations can we obtain from interpreting partial dependency plots (plots describing, given our modeling choice, the potentially nonlinear shape of associations between predictors and readmissions) of the most important predictors of 30-day readmission? METHODS: National Medicare claims data (chosen because this database represents a large proportion of patients undergoing TJA annually) were analyzed for patients undergoing inpatient TJA between October 2016 and September 2018. A total of 679,041 TJAs (239,391 THAs [61.3% women, 91.9% White, 52.6% between 70 and 79 years old] and 439,650 TKAs [63.3% women, 90% White, 55.2% between 70 and 79 years old]) were included. Model features included demographics, county-level social determinants of health, prior-year (365-day) hospital and surgeon TJA procedure volumes, and clinical classification software-refined diagnosis and procedure categories summarizing each patient's Medicare claims 365 days before TJA. Machine-learning models, namely generalized additive models with pairwise interactions (prediction models consisting of both univariate predictions and pairwise interaction terms that allow for nonlinear effects), were trained and evaluated for predictive performance using area under the receiver operating characteristic (AUROC; 1.0 = perfect discrimination, 0.5 = no better than random chance) and precision-recall curves (AUPRC; equivalent to the average positive predictive value, which does not give credit for guessing "no readmission" when this is true most of the time, interpretable relative to the base rate of readmissions) on two holdout samples. All admissions (except the last 2 months' worth) were collected and split randomly 80%/20%. The training cohort was formed with the random 80% sample, which was downsampled (so it included all readmissions and a random, equal number of nonreadmissions). The random 20% sample served as the first test cohort ("random holdout"). The last 2 months of admissions (originally held aside) served as the second test cohort ("2-month holdout"). Finally, feature importances (the degree to which each variable contributed to the predictions) and partial dependency plots were investigated to answer the second and third research questions. RESULTS: For the random holdout sample, model performance values in terms of AUROC and AUPRC were 0.65 and 0.087, respectively, for THA and 0.66 and 0.077, respectively, for TKA. For the 2-month holdout sample, these numbers were 0.66 and 0.087 and 0.65 and 0.075. Thus, our nonlinear models incorporating a wide variety of preoperative features from Medicare claims data could not well-predict the individual likelihood of readmissions (that is, the models performed poorly and are not appropriate for clinical use). The most predictive features (in terms of mean absolute scores) and their partial dependency graphs still confer information about population-level associations with increased risk of readmission, namely with older patient age, low prior 365-day surgeon and hospital TJA procedure volumes, being a man, patient history of cardiac diagnoses and lack of oncologic diagnoses, and higher county-level rates of hospitalizations for ambulatory-care sensitive conditions. Further inspection of partial dependency plots revealed nonlinear population-level associations specifically for surgeon and hospital procedure volumes. The readmission risk for THA and TKA decreased as surgeons performed more procedures in the prior 365 days, up to approximately 75 TJAs (odds ratio [OR] = 1.2 for TKA and 1.3 for THA), but no further risk reduction was observed for higher annual surgeon procedure volumes. For THA, the readmission risk decreased as hospitals performed more procedures, up to approximately 600 TJAs (OR = 1.2), but no further risk reduction was observed for higher annual hospital procedure volumes. CONCLUSION: A large dataset of Medicare claims and machine learning were inadequate to provide a clinically useful individual prediction model for 30-day unplanned readmissions after TKA or THA, suggesting that other factors that are not routinely collected in claims databases are needed for predicting readmissions. Nonlinear population-level associations between low surgeon and hospital procedure volumes and increased readmission risk were identified, including specific volume thresholds above which the readmission risk no longer decreases, which may still be indirectly clinically useful in guiding policy as well as patient decision-making when selecting a hospital or surgeon for treatment. LEVEL OF EVIDENCE: Level III, therapeutic study.

Evaluation of Mechanically-Assisted Crevice Corrosion of Different Modular Dual Mobility Constructs.

BACKGROUND: Modular dual mobility (MDM) acetabular component use is rising in total hip arthroplasty. However, concern of mechanically assisted crevice corrosion (MACC) at the shell-liner interface remains. We investigated shell-liner corrosion using retrieval analyses and corrosion chamber testing. METHODS: We analyzed fretting and corrosion on 10 matched pairs of 2 commercial MDM constructs (MDM1 and MDM2). Also, pristine pairs of Ti6Al4V shells and CoCrMo liners from 3 commercial dual mobility systems (MDM1, MDM2, and MDM3) were tested in vitro to model MACC performance. Three pairs of each were placed into an electrochemical chamber with stepwise increasing cyclic compression loads while measuring currents generated at the shell-liner taper. Onset fretting loads and fretting currents were calculated. RESULTS: Corrosion damage scores on retrieved components were low but higher in the MDM2 to MDM1 liners (P = .006), specifically outside the taper region (P = .00003). Fretting currents were higher in the MDM2 than in MDM1 or MDM3 (P = .011). Onset loads were also higher in the MDM2 (P = .001). CONCLUSION: Among retrieved liners, MDM2 tapers seem prone to non-mechanical corrosion modes. Higher onset loads and fretting currents in MDM2 tapers indicate greater MACC resistance but higher severity once corrosion begins. Differences among the devices were likely due to taper design and surface finish. Currents in all 3 were <5 µA, much lower than those observed with head-neck tapers. Our findings suggest that, among the types of corrosion observed in these MDM designs, mechanically driven corrosion may not be the most significant.

Effect of Duloxetine on Opioid Use and Pain After Total Knee Arthroplasty: A Triple-Blinded Randomized Controlled Trial.

BACKGROUND: Duloxetine, a serotonin-norepinephrine dual reuptake inhibitor, may improve analgesia after total knee arthroplasty (TKA). Previous studies had one primary outcome, did not consistently use multimodal analgesia, and used patient-controlled analgesia devices, potentially delaying discharge. We investigated whether duloxetine would reduce opioid consumption or pain with ambulation. METHODS: A total of 160 patients received 60 mg duloxetine or placebo daily, starting from the day of surgery and continuing 14 days postoperatively. Patients received neuraxial anesthesia, peripheral nerve blocks, acetaminophen, nonsteroidal anti-inflammatory drugs, and oral opioids as needed. The dual primary outcomes were Numeric Rating Scale (NRS) scores with movement on postoperative days 1, 2, and 14, and cumulative opioid consumption surgery through postoperative day 14. RESULTS: Duloxetine was noninferior to placebo for both primary outcomes and was superior to placebo for opioid consumption. Opioid consumption (mean ± SD) was 288 ± 226 mg OME [94, 385] vs 432 ± 374 [210, 540] (duloxetine vs placebo) P = .0039. Pain scores on POD14 were 4.2 ± 2.0 vs 4.8 ± 2.2 (duloxetine vs placebo) P = .018. Median satisfaction with pain management was 10 (8, 10) and 8 (7, 10) (duloxetine vs placebo) P = .046. Duloxetine reduced interference by pain with walking, normal work, and sleep. CONCLUSION: The 29% reduction in opioid use corresponds to 17 fewer pills of oxycodone, 5 mg, and was achieved without increasing pain scores. Considering the ongoing opioid epidemic, duloxetine can be used to reduce opioid usage after knee arthroplasty in selected patients that can be appropriately monitored for potential side effects of the medication.

A Postmortem Analysis of Polyethylene Damage and Periprosthetic Tissue in Rotating Platform and Fixed Bearing Tibial Inserts.

BACKGROUND: Mobile bearing designs are intended to reduce wear, but mixed results were reported from retrieval analyses. Postmortem evaluation (PM) provides the opportunity to assess polyethylene damage in successful implants. We compared damage patterns, MRI presentation, and histology between mobile-bearing and fixed tibial inserts retrieved postmortem and compared these results to our prior findings from implants retrieved at revision. METHODS: Eleven postmortem knees with rotating platform (RP) implants and 13 with fixed bearing (FB) implants were examined. All were MRI scanned, and tissue samples were collected from standardized regions for histology. Polyethylene inserts were subjectively scored to assess articular, backside, and PS post surfaces for damage modes and severity. RESULTS: Average duration of implantation was 9.3 years (1.7-19.6 years). Surface burnishing was the most common polyethylene damage mode. Average damage scores were higher for RP (53.4) compared to FB inserts (34.4) due to greater backside damage (13.4 for RP vs 1.4 for FB). A minimal difference in damage was observed on the articular surfaces (37.4 RP vs 30.0 FB). Mild innate macrophage reactions were seen in 8 (72.7%) RP and 5 (45.5%) FB specimens. Polyethylene particles were identified in 7 (63.6%) RP and 3 (27.7%) FB specimens. CONCLUSIONS: Postmortem inserts showed low damage levels and mild tissue reactions compared to those reported for implants removed at revision arthroplasty. Nonetheless, trends in comparing RP and FB inserts were consistent with those seen in retrieval analyses, demonstrating the usefulness of retrieval studies in capturing performance differences among TKA designs.

Development and Validation of Crosswalks Between the Western Ontario & McMaster Universities Osteoarthritis Index and Hip Disability and Osteoarthritis Outcome Score Joint Replacement/Knee Injury and Osteoarthritis Outcome Score Joint Replacement.

BACKGROUND: The wide variety of patient-reported outcome measures used to assess outcomes following total joint arthroplasty can present a substantial methodological obstacle when attempting to compare information across studies or between institutions. A simple solution is to create crosswalks that reliably convert scores between patient-reported outcome measures. Our goal is to create and validate crosswalks between the commonly used Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) and short-form versions of the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR)/Knee Injury and Osteoarthritis Outcome Score (KOOS JR.). METHODS: Patients in our joint replacement registry were included if they underwent primary total hip arthroplasty (n = 4649) or total knee arthroplasty (n = 3750) for osteoarthritis between May 2007 and February 2012. We used their preoperative and 2-year postoperative HOOS scores (n = 6351) or KOOS scores (n = 4688) to generate the patients' WOMAC and HOOS JR/KOOS JR scores. The equipercentile equating method was applied to create 10 crosswalks: HOOS JR/KOOS JR to WOMAC Total (WOMAC-T), and WOMAC-T, WOMAC Pain (WOMAC-P), WOMAC Stiffness (WOMAC-S), and WOMAC Function (WOMAC-F) to HOOS JR/KOOS JR. Crosswalk validity was assessed by comparing actual and derived scores using Spearman's rank correlation coefficients in a bootstrapped cohort. RESULTS: All 10 crosswalks showed strong positive correlations ranging from 0.846 (WOMAC-S to KOOS JR) to 0.981 (HOOS JR to WOMAC-T). CONCLUSION: We created and validated 10 crosswalks between WOMAC and HOOS JR/KOOS JR. We recommend using the crosswalks between WOMAC-T and HOOS JR/KOOS JR when possible, as they demonstrated the highest correlation. WOMAC-F or WOMAC-P should be used in favor of WOMAC-S if only subscores are available. The HOOS JR/KOOS JR should only be converted to a WOMAC-T. LEVEL OF EVIDENCE: Level III.

Changes in opioid discharge prescriptions after primary total hip and total knee arthroplasty affect opioid refill rates and morphine milligram equivalents : an institutional experience of 20,000 patients.

AIMS: Due to the opioid epidemic in the USA, our service progressively decreased the number of opioid tablets prescribed at discharge after primary hip (THA) and knee (TKA) arthroplasty. The goal of this study was to analyze the effect on total morphine milligram equivalents (MMEs) prescribed and post-discharge opioid repeat prescriptions. METHODS: We retrospectively reviewed 19,428 patients undergoing a primary THA or TKA between 1 February 2016 and 31 December 2019. Two reductions in the number of opioid tablets prescribed at discharge were implemented over this time; as such, we analyzed three periods (P1, P2, and P3) with different routine discharge MME (750, 520, and 320 MMEs, respectively). We investigated 90-day refill rates, refill MMEs, and whether discharge MMEs were associated with represcribing in a multivariate model. RESULTS: A discharge prescription of < 400 MMEs was not a risk factor for opioid represcribing in the entire population (p = 0.772) or in opioid-naïve patients alone (p = 0.272). Procedure type was the most significant risk factor for narcotic represcribing, with unilateral TKA (hazard ratio (HR) = 5.62), bilateral TKA (HR = 6.32), and bilateral unicompartmental knee arthroplasty (UKA) (HR = 5.29) (all p < 0.001) being the highest risk for refills. For these three procedures, there was approximately a 5% to 6% increase in refills from P1 to P3 (p < 0.001); however, there was no significant increase in refill rates after any hip arthroplasty procedures. Total MMEs prescribed were significantly reduced from P1 to P3 (p < 0.001), leading to the equivalent of nearly 500,000 fewer oxycodone 5 mg tablets prescribed. CONCLUSION: Decreasing opioids prescribed at discharge led to a statistically significant reduction in total MMEs prescribed. While the represcribing rate did not increase for any hip arthroplasty procedure, the overall refill rates increased by about 5% for most knee arthroplasty procedures. As such, we are now probably prescribing an appropriate amount of opioids at discharge for knee arthroplasty procedure, but further reductions may be possible for hip arthroplasty procedures. Cite this article: Bone Joint J 2021;103-B(7 Supple B):103-110.

Fretting and corrosion of metal liners from modular dual mobility constructs : a retrieval analysis.

AIMS: Dual mobility implants in total hip arthroplasty are designed to increase the functional head size, thus decreasing the potential for dislocation. Modular dual mobility (MDM) implants incorporate a metal liner (e.g. cobalt-chromium alloy) in a metal shell (e.g. titanium alloy), raising concern for mechanically assisted crevice corrosion at the modular liner-shell connection. We sought to examine fretting and corrosion on MDM liners, to analyze the corrosion products, and to examine histologically the periprosthetic tissues. METHODS: A total of 60 retrieved liners were subjectively scored for fretting and corrosion. The corrosion products from the three most severely corroded implants were removed from the implant surface, imaged using scanning electron microscopy, and analyzed using Fourier-transform infrared spectroscopy. RESULTS: Fretting was present on 88% (53/60) of the retrieved liners, and corrosion was present on 97% (58/60). Fretting was most often found on the lip of the taper at the transition between the lip and the dome regions. Macrophages and particles reflecting an innate inflammatory reaction to corrosion debris were noted in six of the 48 cases for which periprosthetic tissues were examined, and all were associated with retrieved components that had high corrosion scores. CONCLUSION: Our results show that corrosion occurs at the interface between MDM liners and shells and that it can be associated with reactions in the local tissues, suggesting continued concern that this problem may become clinically important with longer-term use of these implants. Cite this article: Bone Joint J 2021;103-B(7):1238-1246.

Adverse Local Tissue Reactions are Common in Asymptomatic Individuals After Hip Resurfacing Arthroplasty: Interim Report from a Prospective Longitudinal Study.

BACKGROUND: The evaluation of the natural history prevalence of adverse local tissue reactions (ALTRs) using MRI has focused only on metal-on-metal (MoM) bearing surfaces without comparison to nonMoM bearing surfaces. QUESTIONS/PURPOSES: To determine (1) the longitudinal changes and differences in blood metal ion levels in patients with hip resurfacing arthroplasty (HRA), ceramic-on-ceramic (CoC) THA, and metal-on-polyethylene (MoP) THA compared with those undergoing ceramic-on-polyethylene (CoP) THA; (2) how the longitudinal change of synovial reaction classification in patients with HRA, CoC THA, and MoP THA compares with those undergoing CoP THA, and whether there is an association between the presence of an ALTR or metallosis on MRI with corresponding patient-reported outcomes, or the presence of capsular dehiscence; and (3) differences in blood metal ion levels between patients undergoing HRA with an ALTR or metallosis on MRI and those with HRA without these conditions. METHODS: Between March 2014 and February 2019, 22,723 patients underwent primary HRA and THA at one center. Patients received an HRA based on their desired athletic level after surgery and the presence of normal acetabular and proximal femoral bone morphology without osteopenia or osteoporosis. Two percent (342 of 22,723) of patients were contacted to participate, and 71% (243 of 342 hips in 206 patients) were enrolled for analysis at baseline. The patients underwent arthroplasty for degenerative joint disease, and 25 patients withdrew over the course of the study. We included patients who were more than 1 year postarthroplasty. All participants had an MRI examination and blood serum ion testing and completed a Hip Disability and Osteoarthritis Outcome Score survey annually for four years (baseline, year 1, year 2, year 3). Morphologic and susceptibility-reduced MR images were evaluated by a single radiologist not involved in the care of patients for the presence and classification of synovitis (Gwet AC1: 0.65 to 0.97), synovial thickness, and volume (coefficient of repeatability: 1.8 cm3). Linear mixed-effects models were used to compare the mean synovial thickness, synovial volume, and Hip Disability and Osteoarthritis Outcome Score subscales between bearing surfaces at each timepoint and within each bearing surface over time. Marginal Cox proportional hazards models were used to compare the time to and the risk of developing ALTR only, metallosis only, and ALTR or metallosis between bearing surfaces. All models were adjusted for age, sex, BMI, and length of implantation based on known confounders for hip arthroplasty. Adjustment for multiple comparisons was performed using the Dunnett-Hsu method. RESULTS: Patients with unilateral HRA had higher cobalt and chromium serum ion levels (baseline: 1.8 ± 0.8 ppb, year 1: 2.0 ± 1.5 ppb, year 2: 2.1 ± 1.2 ppb, year 3: 1.6 ± 0.7 ppb) than those with unilateral CoP bearings (baseline: 0.0 ± 0.1 ppb, year 1: 0.1 ± 0.3 ppb, year 2: 0.0 ± 0.2 ppb, year 3: 0.0 ± 0.0 ppb) at all timepoints (p < 0.001 for each time point). More patients who received an HRA developed ALTR or metallosis on MRI than did patients with CoP bearings (hazard ratio 4.8 [95% confidence interval 1.2 to 18.4]; p = 0.02). There was no association between the longitudinal change of synovial reaction to ALTR or metallosis on MRI with patient-reported outcomes. In addition, there was no association between the presence of dehiscence at baseline and the subsequent development of ALTR or metallosis, as seen on MRI. There were elevated cobalt (4.7 ± 3.5 ppb) and chromium (4.7 ± 2.6 ppb) serum levels in patients with unilateral HRA who had an ALTR or metallosis present on MRI at year 1 compared with patients without an ALTR or metallosis on MRI (cobalt: 1.8 ± 1.0 ppb, mean difference 4.7 ppb [95% CI 3.3 to 6.0]; p < 0.001; chromium: 2.3 ± 0.5 ppb, mean difference 3.6 ppb [95% CI 2.2 to 5.0]; p < 0.001) as well as for chromium at year 3 (3.9 ± 2.4 ppb versus 2.2 ± 1.1 ppb, mean difference 1.3 ppb [95% CI 0.3 to 2.4]; p = 0.01). CONCLUSION: We found a higher proportion of ALTR or metallosis on MRI in patients with HRA compared with patients with CoP, even when patient self-assessed symptomatology of those with an ALTR or metallosis on MRI was not different than the absence of these features. MRI detected ALTRs in high-function patients, emphasizing that an annual clinical assessment dependent on survey or blood ion testing alone may not detect soft tissue complications. The results of this study are in line with prior consensus recommendations of using MRI as part of a routine follow-up protocol for this patient population. LEVEL OF EVIDENCE: Level III, therapeutic study.

Sequencing of Circulating Microbial Cell-Free DNA Can Identify Pathogens in Periprosthetic Joint Infections.

BACKGROUND: Over 1 million Americans undergo joint replacement each year, and approximately 1 in 75 will incur a periprosthetic joint infection. Effective treatment necessitates pathogen identification, yet standard-of-care cultures fail to detect organisms in 10% to 20% of cases and require invasive sampling. We hypothesized that cell-free DNA (cfDNA) fragments from microorganisms in a periprosthetic joint infection can be found in the bloodstream and utilized to accurately identify pathogens via next-generation sequencing. METHODS: In this prospective observational study performed at a musculoskeletal specialty hospital in the U.S., we enrolled 53 adults with validated hip or knee periprosthetic joint infections. Participants had peripheral blood drawn immediately prior to surgical treatment. Microbial cfDNA from plasma was sequenced and aligned to a genome database with >1,000 microbial species. Intraoperative tissue and synovial fluid cultures were performed per the standard of care. The primary outcome was accuracy in organism identification with use of blood cfDNA sequencing, as measured by agreement with tissue-culture results. RESULTS: Intraoperative and preoperative joint cultures identified an organism in 46 (87%) of 53 patients. Microbial cfDNA sequencing identified the joint pathogen in 35 cases, including 4 of 7 culture-negative cases (57%). Thus, as an adjunct to cultures, cfDNA sequencing increased pathogen detection from 87% to 94%. The median time to species identification for cases with genus-only culture results was 3 days less than standard-of-care methods. Circulating cfDNA sequencing in 14 cases detected additional microorganisms not grown in cultures. At postoperative encounters, cfDNA sequencing demonstrated no detection or reduced levels of the infectious pathogen. CONCLUSIONS: Microbial cfDNA from pathogens causing local periprosthetic joint infections can be detected in peripheral blood. These circulating biomarkers can be sequenced from noninvasive venipuncture, providing a novel source for joint pathogen identification. Further development as an adjunct to tissue cultures holds promise to increase the number of cases with accurate pathogen identification and improve time-to-speciation. This test may also offer a novel method to monitor infection clearance during the treatment period. LEVEL OF EVIDENCE: Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Retrieval Analysis of Polyethylene Components in Rotating Hinge Knee Arthroplasty Implants.

BACKGROUND: This study examined a cohort of retrieved rotating hinge (RH) total knee arthroplasty implants of four different designs with emphasis on the surface damage observed on the polyethylene components. Our purpose was to determine if differences in polyethylene damage existed among the designs, and if those differences could be explained by differences in design characteristics. MATERIALS AND METHODS: Seventy-two RH implants from four manufacturers (DePuy LPS/SROM, Zimmer NexGen, Stryker Howmedica MRH, and Biomet Finn-OSS) removed at the time of revision performed between 2002 and 2017 were identified in our institutional retrieval registry. Damage to the surfaces of the polyethylene was assessed using a subjective grading system and evaluated in multiple zones. Design characteristics that were evaluated included the following: location of the dwell point on the polyethylene component, posterior position of the axle, and amount of hyperextension and rotation allowed by the implant. RESULTS: There were no differences in total damage scores between the four implant groups (P = .45). The Stryker Howmedica MRH group showed the least backside wear of all implants but significantly more articular-sided wear compared with two of the other three groups. All implants except NexGen showed increased total damage scores in implants revised for mechanical (vs nonmechanical) reasons and in implants with a longer duration of implantation. CONCLUSION: No single implant design emerged as superior in terms of minimizing polyethylene wear damage. Polyethylene damage existed in various locations but was not different in severity across designs, suggesting that there is no clear superior RH design that minimizes overall articular surface wear compared with other designs.

Coronavirus Disease 2019 Exposure in Surgeons and Anesthesiologists at a New York City Specialty Hospital: A Cross-Sectional Study of Symptoms and SARS-CoV-2 Antibody Status.

OBJECTIVE: We measured the seroprevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) immunoglobulin G (IgG) antibodies among surgeons and anesthesiologists and associated antibody status with coronavirus disease 2019 (COVID-19) clinical illness. METHODS: A cross-sectional study of SARS-CoV-2 IgG seroprevalence with a survey assessing demographics, SARS-CoV-2 exposure risk, and COVID-19 illness. The primary outcome was the period prevalence of SARS-CoV-2 IgG antibodies associated with COVID-19 illness. RESULTS: One hundred forty three surgeons and anesthesiologists completed both serology and survey testing. We found no significant relationships between antibody status and clinical role (anesthesiologist, surgeon), mode of commuting to work, other practice settings, or place of residence. SARS-CoV-2 IgG seroprevalence was 9.8%. Positive IgG status was highly correlated with presence of symptoms of COVID-19 illness. CONCLUSIONS: These results suggest the relative safety of surgeons and anesthesiologists where personal protective equipment (PPE) is available and infection control protocols are implemented.

Independent Risk Factors for Transfusion in Contemporary Revision Total Hip Arthroplasty.

BACKGROUND: The incidence of transfusion in contemporary revision total hip arthroplasty (THA) remains high despite recent advances in blood management, including the use of tranexamic acid. The purpose of this prospective investigation was to determine independent risk factors for transfusion in revision THA. METHODS: Six centers prospectively collected data on 175 revision THAs. A multivariable logistic analysis was performed to determine independent risk factors for transfusion. Revisions were categorized into subgroups for analysis, including femur-only, acetabulum-only, both-component, explantation with spacer, and second-stage reimplantation. Patients undergoing an isolated modular exchange were excluded. RESULTS: Twenty-nine patients required at least one unit of blood (16.6%). In the logistic model, significant risk factors for transfusion were lower preoperative hemoglobin, higher preoperative international normalized ratio (INR), and longer operative time (P < .01, P = .04, P = .05, respectively). For each preoperative 1g/dL decrease in hemoglobin, the chance of transfusion increased by 79%. For each 0.1-unit increase in the preoperative INR, transfusion chance increased by 158%. For each additional operative hour, the chance of transfusion increased by 74%. There were no differences in transfusion rates among categories of revision hip surgery (P = .23). No differences in demographic or surgical variables were found between revision types. CONCLUSION: Despite the use of tranexamic acid, transfusions are commonly required in revision THA. Preoperative hemoglobin and INR optimization are recommended when medically feasible. Efforts should also be made to decrease operative time when technically possible.

Reduction of Opioid Quantities at Discharge After TKA Did Not Increase the Risk of Manipulation Under Anesthesia: An Institutional Experience.

BACKGROUND: In response to the opioid epidemic, our arthroplasty service sequentially reduced the opioid quantities prescribed at primary total knee arthroplasty (TKA) discharge. However, its effect on postdischarge pain control and rehabilitation is unknown. We assessed if this decrease was associated with an increase in the risk of manipulation under anesthesia (MUA). METHODS: We retrospectively reviewed 8799 patients undergoing primary TKA from 2016 to 2019 at a single institution. There were two institution-wide reductions in the amount of opioids prescribed at discharge; therefore, we divided patients into 3 periods (P1, P2, and P3). The mean discharge morphine milligram equivalents (MMEs) went from 900 MMEs to ~525 MMEs to ~320 MMEs in P1, P2, and P3, respectively. We analyzed MUA rates and if lower discharge MMEs was a risk factor for MUA in a multivariate model. We also compared refill patterns (rates, number, refill MMEs, and total MMEs) between MUA and non-MUA patients. RESULTS: The rate of MUA did not increase with reduced discharged opioids (5.5% in P1, 5.8% in P2, and 4.6% in P3, P = .74). In a multivariate analysis, discharge MMEs of <450 was not a significant risk factor for MUA. However, a diagnosis of chronic pain (OR = 1.86, P < .001) and an elevated body mass index (OR = 1.02 per unit increase, P < .001) were significant risk factors. We did not find significant differences in any opioid prescription refill patterns in MUA and non-MUA patients. CONCLUSION: Serial reductions in discharge MMEs after primary TKA did not significantly affect the rate of MUA, a surrogate marker for pain control and the rehabilitative process.

Is There an Association Between Negative Patient-Experience Comments and Perioperative Outcomes After Primary Total Hip Arthroplasty?

BACKGROUND: Multiple stakeholders are interested in improving patient experience after primary total hip arthroplasty due to shifts toward patient-centered care. Patient free-text narratives are a potentially valuable but largely unexplored source of data. METHODS: The records of 383 patients who underwent primary total hip arthroplasty between August 2016 and August 2019 were combined with vendor-supplied patient satisfaction data, which included patient free-text comments and the Press Ganey satisfaction survey. A total of 1295 patient comments were analyzed for sentiment, and negative comments were categorized into nine themes. Postoperative outcomes, patient-reported outcome measures, and traditional measures of satisfaction were compared between patients who provided a negative comment vs those who did not. Multivariable regression was used to determine perioperative variables associated with providing a negative comment. RESULTS: Of the 1295 patient comments: 54% were positive, 24% were negative, 10% were mixed, and 12% were neutral. Top two themes of negative comments were room condition (25%) and inefficient communication (23%). There were no differences in studied outcomes (eg. peak pain intensity, length of stay, or improvements in hip injury and osteoarthritis outcome scores Jr. and pain visual analog scale scores at 6-week follow-up) between those who provided negative comments vs those who did not (P > .05). However, patients who made negative comments were less likely to recommend their hospital care to peers (P < .001). Finally, patients who had >2 allergies (P = .024) were more likely to provide negative comments. CONCLUSION: The present study demonstrates that patient satisfaction appears not to be a reliable sole proxy for traditional objective outcome measures of pain relief and functional improvement.

The Hip-Spine Relationship: The Importance of Femoral Version.

Recent investigations have confirmed the impact of spinopelvic mobility upon functional acetabular position. However, it is critical to remember the impact of femoral component position as it contributes to combined version of the hip joint. It has been demonstrated that implant position can affect articular wear, the potential for prosthetic impingement as well as a cause of joint instability. Ensuring an impingement-free range of motion at the time of hip replacement is critical to long-term survivorship. During hip reconstruction, there is significant latitude in acetabular component positioning but femoral component version is often dictated by native femoral anatomy and in some instances cannot be adjusted. Understanding the role that femoral version plays in prosthetic hip joint kinematics should provide surgeons with a better understanding of this complex relationship.

The Optimal Dosing Regimen for Tranexamic Acid in Revision Total Hip Arthroplasty: A Multicenter Randomized Clinical Trial.

BACKGROUND: The purpose of this multicenter, randomized trial was to determine the optimal dosing regimen of tranexamic acid (TXA) to minimize perioperative blood loss in revision total hip arthroplasty. METHODS: Six centers prospectively randomized 175 patients to 1 of 4 regimens: (1) 1-g intravenous (IV) TXA prior to incision (the single-dose IV group), (2) 1-g IV TXA prior to incision followed by 1-g IV TXA after arthrotomy wound closure (the double-dose IV group), (3) a combination of 1-g IV TXA prior to incision and 1-g intraoperative topical TXA (the combined IV and topical group), or (4) 3 doses totaling 1,950-mg oral TXA (the multidose oral group). Randomization was based on revision subgroups to ensure equivalent group distribution. An a priori power analysis (α = 0.05; ß = 0.80) determined that 40 patients per group were required to identify a >1-g/dL difference in postoperative hemoglobin reduction between groups. Per-protocol analysis involved an analysis of variance, Fisher exact tests, and two 1-sided t tests for equivalence. Demographic and surgical variables were equivalent between groups. RESULTS: No significant differences were found between TXA regimens when evaluating reduction in hemoglobin (3.4 g/dL for the single-dose IV group, 3.6 g/dL for the double-dose IV group, 3.5 g/dL for the combined IV and topical group, and 3.4 g/dL for the multidose oral group; p = 0.95), calculated blood loss (p = 0.90), or transfusion rates (14% for the single-dose IV group, 18% for the double-dose IV group, 17% for the combined group, and 17% for the multidose oral group; p = 0.96). Equivalence testing revealed that all possible pairings were statistically equivalent, assuming a >1-g/dL difference in hemoglobin reduction as clinically relevant. There was 1 venous thromboembolism, with no differences found between groups (p = 1.00). CONCLUSIONS: All 4 TXA groups tested had equivalent blood-sparing properties in the setting of revision total hip arthroplasty, with a single venous thromboembolism reported in this high-risk population. Based on the equivalence between groups, surgeons should utilize whichever of the 4 investigated regimens is best suited for their practice and hospital setting. Given the transfusion rate in revision total hip arthroplasty despite TXA utilization, further work is required in this area. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.