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Background: The American Academy of Orthopaedic Surgeons defined the acceptable threshold for elective safe surgery as a body mass index (BMI) under 40 due to the increased risk of complications. A consequence of this recommendation has been a hard cutoff based on BMI, which restricts access to care for an increasingly large and diverse population. There is an improved understanding that excess adipose tissue confers additional risk for postoperative complications, including infection, through mechanical and physiologic mechanisms. But, it is unclear if BMI is an accurate indicator of adiposity in total joint arthroplasty (TJA) patients and, thus, whether BMI is capturing clinically relevant information in obese patients. Our objective was to determine the relationship between peri-incisional adiposity (PIA) and BMI in a consecutive series of diverse primary TJA patients., Methods: A consecutive series of patients indicated for primary TJA were preoperatively evaluated. For each patient, the following variables were collected: BMI and measures of PIA on radiographs and ultrasounds., Results: In THA patients (N = 99), Pearson's correlation coefficient (r) = 0.436, which indicates a moderate correlation between BMI and adiposity. In total knee arthroplasty patients (N = 271), r = 0.395 for femoral PIA (FPIA) and r = 0.249 for tibial PIA, which indicates a weak correlation between BMI and adiposity measured on radiography. In total knee arthroplasty patients, r = 0.560 for femoral PIA and r = 0.544 for tibial PIA, which indicates a moderate correlation between BMI and adiposity measured on ultrasound., Conclusions: Quantification of obesity has become a common practice in the preoperative evaluation of primary TJA patients. The intent is to determine the magnitude of adipose tissue, which is one of the main drivers of postoperative complications in obesity. The BMI is ubiquitously used as a proxy for obesity due to its simplicity of attainment and calculation. We report that BMI has a weak-to-moderate association with PIA in this population. These findings indicate that BMI may not accurately represent the condition of peri-incisional adipose tissue and, thus, is not capturing the relevant obesity data for preoperative risk stratification in primary TJA patients., Level of Evidence: III., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: For reimbursement purposes, current coding fails to reflect the true complexity and resource utilization of hospital encounters for surgeries performed to treat periprosthetic total hip arthroplasty (THA) infection. Therefore, when compared to aseptic revisions, we sought to determine (1) Is length of stay (LOS) longer for septic surgeries? (2) Are septic procedures more expensive? and (3) How do different surgical procedures for infection compare with aseptic revisions on hospital LOS and charges?, Methods: Retrospective chart review of 596 unilateral THA reoperations (473 patients) performed at a single institution (January 2015 to November 2020). Demographics, professional (ie, physicians), and technical (ie, room, implants) hospital charges per case were compared between 6 different surgery types: (1) aseptic revision (control; n = 364); (2) debridement, antibiotics, and implant retention (n = 11); (3) explantation (n = 145); (4) spacer exchange (n = 7); (5) 2-stage reimplantation (n = 59); and (6) 1-stage reimplantation (n = 10)., Results: Overall, septic surgeries (n = 232) had longer LOS (mean 6.3 vs 3.3 days, P < .001) and 43% higher total charges ( P < .001), vs aseptic revisions. Particularly, explantations had longer LOS (7.1 vs 3.3 days) and 56% higher total charges (both P < .001). When compared to aseptic revisions, proportional total charges for septic procedures were debridement, antibiotics, and implant retention +29%, P  = .4; explantation +56%, P < .001; spacer exchange +69%, P  = .008; 2-stage reimplantation +11%, P  = .659; and 1-stage reimplantation +46%, P  = .06., Conclusions: Some surgical procedures performed to treat periprosthetic THA infection are associated with longer LOS and significantly higher hospital charges when compared to aseptic revisions. Reimbursement adjustment is needed as current coding for septic reoperations does not reflect actual hospital resource consumption and this situation may limit access to patient care., (© 2024 The Authors.)

Purpose: Release of the first dorsal compartment is a described technique during volar approach for distal radius fracture fixation. Our objective was to determine whether release of the first dorsal compartment during volar approach for distal radius fracture fixation impacted corresponding symptoms in pre-existing de Quervain disease., Methods: A prospective, randomized cohort study was performed with patients grouped for release (release group) or no release (control group) of the first dorsal compartment during volar approach for distal radius fracture fixation. Inclusion required a confirmed diagnosis of de Quervain disease within the 12 months preceding a distal radius fracture., Results: Patients in the release group were significantly less symptomatic than those in the control group at 3 and 6 months after surgery. Lateral pinch strength in the release group was significantly greater than that in the control group at 3 and 6 months after surgery., Conclusions: The current results demonstrated a significantly greater reduction in de Quervain disease symptoms in the release group compared with the no release group during the short-term follow-up. This indicates that routine first dorsal compartment release during distal radius fracture fixation may expedite symptom relief in patients with de Quervain disease., Type of Study/level of Evidence: Therapeutic I., Competing Interests: No benefits in any form have been received or will be received related directly to this article., (© 2024 The Authors.)

Background: Evidence on the effects of time-to-failure from primary total hip arthroplasty (THA) to aseptic first-revision on clinical results and patient-reported outcome measures (PROMs) is scarce. Therefore, we sought to compare demographics, operative times, lengths of stay, discharge dispositions, 90-day readmissions, re-revision rates, mortalities, and PROMs between early and late aseptic THA revisions., Methods: This study is a retrospective review of a prospectively collected institutional database of all elective hip procedures. In total, 572 patients who underwent aseptic revision after primary THA from August 2015 to December 2018 were analyzed. Patients were stratified into either early revision (<3-years; n = 176) or late revision (≥3-years; n = 396) cohorts., Results: Significantly more patients were revised earlier for bone-related (ie, periprosthetic fractures) (22.7% versus 8.3%) or other various complications (19.9% versus 5.8%), whereas more late revisions were performed to treat implant-related failures (6.8% versus 37.1%), respectively. Operative time was significantly shorter in early versus late revisions (133 versus 157 minutes). A significantly higher delta-change/improvement from baseline/preoperative to 1-year postoperative was found for hip disability and osteoarthritis outcome score physical function (HOOS-PS), veterans-RAND-12 physical and mental components (VR-12-PCS and MCS, respectively) of early revisions. However, HOOS-PS and HOOS-Pain at 1-year of follow-up were significantly worse in early revisions., Conclusion: With exception of operative time, time-to-failure had no significant influence on clinical results. Despite greater improvements on PROMs from preoperative to postoperative, patients undergoing early revisions after primary THA perceive significantly higher levels of pain and worse physical functionality at 1-year of follow-up., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: In this study, we assess the effects that morbid obesity (body mass index (BMI) ≥ 40) has on: (1) Ninety-day medical complications and readmission rates; (2) costs of care and lengths of stay (LOS); and (3) 2-year implant complications in patients undergoing unicompartmental knee arthroplasty (UKA) versus total knee arthroplasty (TKA)., Methods: A retrospective query of TKA and UKA patients were identified using a national database. Morbidly obese UKA patients were matched 1:5 to morbidly obese TKA patients by demographic and comorbidity profiles. Subgroup analyses were conducted using the same process between morbidly obese UKA patients and BMI <40 TKA patients, as well as to BMI <40 UKA patients., Results: Morbidly obese patients who underwent UKA had significantly fewer medical complications, readmissions, and periprosthetic joint infections than TKA patients; however, UKA patients had greater odds of mechanical loosening (ML). The TKA patients had significantly longer LOS (3.0 versus 2.4 days, P < .001), as well as significantly greater costs of care than UKA patients ($12,869 versus $7,105). Morbidly obese UKA patients had similar rates of medical complications, and significantly lower readmissions, decreased LOS, and decreased costs when compared to TKA patients who had a BMI <40., Conclusion: In patients who have morbid obesity, complications were decreased in UKA compared to TKA. Moreover, morbidly obese UKA patients had lower medical utilizations and similar complication rates when compared to TKA patients with the recommended cutoff of BMI <40. However, UKA patients had greater rates of ML than TKA patients. A UKA may be an acceptable treatment option for unicompartmental osteoarthritis in morbidly obese patients., (Copyright © 2023 Elsevier Inc. All rights reserved.)

» Body mass index (BMI) is a nonspecific measure of general fat composition that demonstrates little conclusive or definitive association with surgical site complications after total knee and total hip arthroplasty.» Quantifying soft-tissue thickness (STT) around the joint of interest has shown positive correlations with complications and is arguably a better predictor than BMI.» In this literature review, 14 articles (7 discussing hips and 7 discussing knees) discussing the association of STT, BMI, and surgical site complications after total hip and knee arthroplasty were scrutinized and summarized to present relevant information necessary to compare STT with BMI.» Five of the 7 studies involving hips and 4 of the 7 studies involving knees show a positive relationship between STT and outcomes including complications and infection, with some claiming STT as a stronger predictor of surgery site problems than BMI.» Since many variables, such as STT measurement technique, surgical outcomes, sample sizes, and surgical approach, varied between the studies, definitive inferences are difficult to make and future studies of bigger sample size and higher power should focus on the described measurement techniques., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSREV/B26)., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: It remains uncertain whether patients who undergo numerous total hip arthroplasty (THA) and/or knee arthroplasty (TKA) revisions exhibit decreased survival. Therefore, we sought to determine if the number of revisions per patient was a mortality predictor., Methods: We retrospectively reviewed 978 consecutive THA and TKA revision patients from a single institution (from January 5, 2015-November 10, 2020). Dates of first-revision or single revision during study period and of latest follow-up or death were collected, and mortality was assessed. Number of revisions per patient and demographics corresponding to first revision or single revision were determined. Kaplan-Meier, univariate, and multivariate Cox-regressions were utilized to determine mortality predictors. The mean follow-up was 893 days (range, 3-2,658)., Results: Mortality rates were 5.5% for the entire series, 5.0% among patients who only underwent TKA revision(s), 5.4% for only THA revision(s), and 17.2% for patients who underwent TKA and THA revisions (P = .019). In univariate Cox-regression, number of revisions per patient was not predictive of mortality in any of the groups analyzed. Age, body mass index (BMI), and American Society of Anesthesiologists (ASA) were significant mortality predictors in the entire series. Every 1 year of age increase significantly elevated expected death by 5.6% while per unit increase in BMI decreased the expected death by 6.7%, ASA-3 or ASA-4 patients had a 3.1 -fold increased expected death compared to ASA-1 or ASA-2 patients., Conclusion: The number of revisions a patient underwent did not significantly impact mortality. Increased age and ASA were positively associated with mortality but higher BMI was negatively associated. If health status is appropriate, patients can undergo multiple revisions without risk of decreased survival., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: The impact of the organism virulence on diagnostic accuracy of D-Dimer for periprosthetic joint infection (PJI) is unknown. Our objective was to assess if the performance of D-Dimer in PJI diagnosis changes with the virulence of the organism(s)., Methods: We retrospectively reviewed 143 consecutive revision total hip arthroplasties/total knee arthroplasties with D-Dimer ordered preoperatively. Operations were performed by 3 surgeons at a single institution (November 2017 through September 2020). There were 141 revisions with complete 2013-International Consensus Meeting-criteria initially included. This criteria was used to classify revisions as aseptic versus septic. Culture-negative septic revisions (n = 8) were excluded, and 133 revisions (47-hips/86-knees; 67-septic/66-aseptic) were analyzed. Based on culture results, septic-revisions were categorized into 'low-virulence (LV/n = 40)' or 'high-virulence (HV/n = 27)'. The D-Dimer threshold (850-ng/mL) was tested against 2013-International Consensus Meeting-criteria ("standard") in identifying septic-revisions (LV/HV) from aseptic-revisions. Sensitivity, specificity, and positive predictive values/negative predictive values (NPV) were determined. Receiver-operating-characteristic-curve-analyses were performed., Results: Plasma D-Dimer showed high sensitivity (97.5%) and NPV (95.4%) in LV septic cases, which appeared to reduce by about 5% in HV septic cases (sensitivity = 92.5% and NPV = 91.3%). However, this marker had poor overall accuracy (LV = 57%; HV = 49.4%), low specificity (LV and HV = 31.8%), and positive predictive values (LV = 46.4%; HV = 35.7%) to diagnose PJI. The area under the curve was 0.647 and 0.622 in LV and HV versus aseptic revisions, respectively., Conclusion: D-Dimer performs poorly to identify septic from aseptic revisions in the setting of LV/HV infecting organisms alike. However, it shows high sensitivity for PJI diagnosis in cases of LV organisms which might be missed by most diagnostic tests., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Antibiotic-loaded bone cement (ALBC) spacers are the mainstay in 2-stage revision, but antibiotics (vancomycin plus aminoglycosides) may undergo systemic absorption, resulting in acute kidney injury (AKI). Data on spacer antibiotics are heterogeneous. Our objective was to review risk factors for AKI and dosage of antibiotics. Significant AKI risk factors were antibiotic concentration greater than 3 or 3.6 g per cement batch, comorbidities, chronic kidney disease, and hypovolemia. Despite similar spacer antibiotic dosing, there was remarkable variability in serum concentrations. To err on the side of caution, it appears that antibiotic dose below 3 g per cement batch might be relatively safe until more evidence surfaces. Consideration of risk factors for AKI calls for appropriate antibiotic use in 2-stage revision. [ Orthopedics . 2023;46(3):e136-e142.].

Evidence on the learning curve associated with robotic-arm-assisted total knee arthroplasty (ra-TKA) is scarce and mostly based on operative time. Thus, the objective of this study was to assess a surgeon's learning experience based on accuracy to reach planned limb alignment and its impact on surgical-characteristics, limb-alignment, and perioperative-outcomes. A retrospective chart review was conducted on a consecutive series of 204 primary ra-TKAs (patients), performed by a single surgeon in a single institution (3/7/2018-to-6/18/2019). Cumulative summation control sequential analysis was used for the assessment of the learning curve using accuracy of reaching the planned limb alignment establishing that surgeries had an initial-learning-phase, followed by a second-consolidation-phase. Baseline demographics, operative/tourniquet times, prosthesis type, and limb alignment were compared between these two phases. Length of stay, discharge disposition, complications, reoperation/readmission (90 days), and total morphine equivalents (TMEs) prescribed were compared between phases. Independent sample t -tests, and chi-squared analyses were performed. ra-TKA demonstrated a learning curve of 110 cases for reaching planned limb alignment ( p  = 0.012). Robotic experience resulted in significantly more proportion of knees in neutral-axis postoperatively ( p  = 0.035) and significant reduction in TMEs prescribed ( p  = 0.04). The mean operative and tourniquet time were found to be significantly lower in second-phase versus the first-phase ( p for both < 0.0001). ra-TKA has a significant learning curve in clinical practice. A surgeon can reach the planned limb alignment with increased accuracy over time (110-cases). Progressive robotic learning and associated operative time efficiency can lead to significantly lower opioid consumption in patients undergoing TKA., Competing Interests: C.A.H. reports personal fees and other from KCI, other from PSI, other from CD Diagnostics, Cymedica, Ferring Pharmaceuticals, Lyfstone, OREF, Orthofix, Inc., Stryker, Zimmer, other from American Journal of Orthopedics, Journal of Arthroplasty, Journal of Hip Surgery, Journal of Knee Surgery, other from American Association of Hip and Knee Surgeons, Mid-American Orthopaedic Association, Musculoskeletal Infection Society, outside the submitted work. Dr. Barsoum reports Royalties from a company or supplier: Thieme, Stryker, Shukla Medical, Exactech. Inc.; Speakers bureau/paid presentations for a company or supplier: Stryker; Paid consultant for a company or supplier: Stryker, Peerwell; Stock or stock options in a company or supplier: Custom Orthopaedic Solutions, Capsico Health, Peerwell, PT Genie, Sight Medical, Health XL; Research support: Zimmer, Third Frontier, Stryker, Orthosensor, NIH, DJO, Inc.; Other financial or material support from a company or supplier: Thieme; Royalties, financial or material support from publishers: Thieme; Editor in Chief: Journal of Hip Surgery. P.D.P. reports Paid consultant for a company or supplier: Stryker, Zimmer. The rest of the authors declare no conflict of interest., (Thieme. All rights reserved.)

Competing Interests: None declared.

Background: It is unknown whether extended oral antibiotic (EOA) prophylaxis reduces periprosthetic joint infection (PJI) rates after aseptic revision total hip (THA) and knee arthroplasty (TKA). The literature is scarce. Therefore, we sought to ascertain whether EOA prophylaxis decreases PJI rates after aseptic first-time revision THA and TKA when compared to standard prophylaxis., Methods: This is a retrospective review of 328 consecutive revisions (3 surgeons, single institution, from September 27, 2017 to December 31, 2019). Preoperative 2013 Musculoskeletal Infection Society (MSIS) criteria, radiographs, and medications were reviewed. Inclusion criteria included aseptic first-time revision THA and TKA. Exclusion criteria were positive intraoperative cultures and/or histology, PJI (2013 MSIS criteria), hemiarthroplasty/partial arthroplasty revision, revision using foreign material (ie, mesh), metastatic bone disease, and intravenous antibiotics >24 hours after surgery. A total of 178 revisions were included, and 2 groups were set apart based on antibiotic prophylactic regime. The following were the groups: (1) EOA prophylaxis (>24 hours, n = 93) and (2) standard prophylaxis (≤24 hours, n = 85). Demographics, joint types, lengths of stay, skin-to-skin operative times, revision types, transfusions, discharge dispositions, and PJIs (per 2013 MSIS criteria) after the first-time revision were compared between groups. There were no significant differences in demographics. However, skin-to-skin operative time was significantly higher in the EOA group (123 minutes versus 98 minutes, P = .01). Mean follow-up was 849 days (range, 15-1,671). Statistical significance was set at a P value lower than .05., Results: Postoperative PJI rates were not significantly different: 2.2% EOA prophylaxis versus 3.5% standard prophylaxis (P = .671)., Conclusion: No significant difference was found between PJI rates between both prophylactic regimens. A large multicenter study with a larger sample size is needed to support EOA after aseptic revisions., Level of Evidence: Level III., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The variation of plasma d-dimer, an inflammatory marker, from pre-explantation to pre-reimplantation in two-stage revision remains unclear. Our objective was to evaluate delta-changes (Δ) in d-dimer, erythrocyte sedimentation rate (ESR), and C-reactive-protein (CRP), to ascertain whether these delta-changes are associated with the outcome of reimplantation. We hypothesized a decrease in d-dimer before reimplantation., Methods: A retrospective review was performed on a consecutive series of 95 two-stage revisions indicated for periprosthetic joint infection. Surgeries were performed by 3 surgeons at a single institution (2018-2020). The minimum follow-up was 1 year. The inclusion criteria comprised availability of d-dimer results at pre-explantation and pre-reimplantation. As a result, only 30 reimplantations were included. Success of reimplantation was defined by Musculoskeletal Infection Society outcome reporting tool: Tier 1/Tier 2 vs Tier 3/Tier 4. Nonparametric tests and Mann-Whitney U-tests were conducted to compare Δd-dimer% (pre-explantation value - pre-reimplantation value/pre-explantation value × 100). The bootstrapped receiver operating characteristic curve analyses with 2,000 replicates of 30 cases were conducted., Results: The median time between explantation and reimplantation was 86 days (interquartile range [IQR] = 77.7-138.5 days). Overall, a paradoxical median percent increase (Δd-Dimer% [INCREMENT] = 12.6%) in d-dimer was found from pre-explantation to pre-reimplantation (IQR = -28.06% to 77.3%). However, there was a percentage decrease in ESR (ΔESR% [DECREMENT] = -40%; IQR = -70.52% to 3.85%) and CRP (ΔCRP% [DECREMENT] = -75%; IQR = -87.43% to -61.34%). The changes in all these markers were not different between Musculoskeletal Infection Society Tier 1/2 and 3/4 outcomes (Δd-Dimer%, P = .146; ΔESR%, P = .946; ΔCRP%, P = .463). With area under curve of 0.676, Δd-dimer% (INCREMENT) appeared to be performing best in diagnosing infection control, which was nonexplanatory., Conclusion: Plasma d-dimer paradoxically increases before reimplantation while other inflammatory markers (ESR/CRP) decrease, emphasizing that surgeons shall adopt caution using d-dimer to make clinical decisions., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: An array of synovial white blood cell (WBC) count and polymorphonuclear differential (PMN%) thresholds have been reported using 2013 Musculoskeletal Infection Society (MSIS) definition which has a poor accuracy to confirm infection control before reimplantation. The workgroup of MSIS recently developed a comprehensive definition of successful infection management. Our objectives were to determine optimal thresholds for WBC count and PMN% associated with reimplantation success based on this new MSIS definition and assess if values above these thresholds indicate decreased survival time., Methods: A retrospective review was conducted on a consecutive series of 133 two-stage hip/knee arthroplasties performed by 15 surgeons (2014-2020) at 2 institutions. All surgeries had a minimum follow-up of 1 year. The inclusion criteria included reporting of preoperative synovial fluid aspiration results. Thus, 88 were finally included. Surgical success was defined by MSIS outcome reporting tool (Tiers 1-4). Receiver operating characteristic curve analyses were performed to estimate optimal thresholds of WBC count and PMN%. A Kaplan-Meier survival analyses with log-rank test were performed., Results: With area under the curve of 0.65, synovial PMN% showed superior accuracy than WBC count (area under the curve = 0.52) in determining outcome of reimplantation. The optimal PMN% threshold (62%) demonstrated sensitivity of 57% and specificity of 77%. The calculated WBC count threshold (2,733/μL) showed poor sensitivity (21%) but high specificity (95%). There was a significant difference in failure-free survival (24 months) between the cases with WBC count higher vs lower than 2,733/μL (P = .002). This was also true for PMN% at 5 months postoperatively (P = .009)., Conclusion: WBC count (2,733/μL) shows very high specificity to confirm successful reimplantation. Both WBC count and PMN% (62%) thresholds can significantly determine reimplantation survival., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: The first known COVID-19 patient in the United States was reported on 1/20/2020. Since then, we noted increased thromboembolic events among our THA/TKA patients. Therefore, we sought to determine: (1) monthly incidences of pulmonary embolism (PE)/deep vein thrombosis (DVT) before and after January/2020 and (2) thromboembolic event rates for primary and revision patients., Methods: We retrospectively obtained from our electronic-medical-records the total monthly number of patients (December/2018-March/2021) who underwent primary or revision THA/TKA, and among them, those who had PE/DVT during each month. Monthly rates of thromboembolic events were calculated and figures were created showing rates throughout time. The cutoff month to define before and after COVID-19 was January/2020., Results: During the study period, 1.6% of patients (312/19068) had PE/DVT [PE (n = 102), DVT (n = 242), both (n = 32)]. Overall rate of PE/DVT before January/2020 was 1.2% (119/9545) and it was 2.0% (193/9523) after that month. Incidences of PE/DVT on April/June/July of 2020 were 3.4%, 3%, 3.4%, respectively. A major increase, when compared to 2019 (1.3%, 1%, 1%, respectively). An unusually high rate of PE was observed on April/2020 (3.4%), more than three times the one observed in any other month. After January/2020, there was an overall major increase of PE/DVT rates, but particularly among revision patients: 6% in five different months including 11.5% on November/2020., Conclusion: There was a major increase of thromboembolic events among THA/TKA patients during the COVID-19 pandemic, predominantly in revision patients. Patients need counseling about this increased risk. It remains uncertain whether more aggressive thromboprophylactic regimes should be followed.

Background: The virulence and antibiotic resistance profile of an infecting organism have been shown to impact the outcomes of periprosthetic joint infection (PJI). However, there are no existing data on the outcomes of PJI caused by Corynebacterium striatum, a rare organism. Thus, our objective is to ascertain: (1) the treatment success of PJI caused by this rare organism and (2) patient characteristics in the setting of C striatum PJI., Methods: A retrospective review was conducted on 741 consecutive PJIs managed at 2 hospital facilities by 8 surgeons (February 4, 2015 to October 30, 2019). The inclusion criteria represented the presence of minimum 1 positive culture of C. striatum. After excluding 1 patient with no follow-up, 15 patients were finally analyzed (9 hips/6 knees). Out of 15 patients, 9 underwent explantation with spacer insertion, 5 underwent irrigation and debridement with polyexchange (I&D), and 1 underwent Girdlestone. Out of 9 explanted patients, only 6 cleared infection and were reimplanted. The clinical staging system for PJI was determined using McPherson classification. The mean follow-ups for I&D and explantation were 35 and 23.5 months, respectively. Success of reimplantation was determined using Delphi criteria., Results: Out of 5 I&D patients, 40% had to be reoperated because of persistent infection. Out of 6 explanted patients who were reimplanted, 67% failed. According to McPherson, 40% of I&D and 22.2% of explanted patients were significantly compromised hosts., Conclusion: C. striatum PJI has a high-treatment failure rate in patient undergoing I&D or 2-stage revision surgery. Surgeons should be aware of the difficulty controlling this PJI and advise patients accordingly., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: In response to the opioid epidemic, Florida recently passed the opioid prescription limiting law, effective since July 1 st , 2018. However, its impact on opioid prescription after total joint arthroplasty (TJA) has not been elucidated. Thus, our objective was to assess if this new law led to reduced opioid prescription after TJA and to determine its impact on perioperative clinical outcomes., Methods: A retrospective chart review was conducted on a consecutive series of 658 primary TJAs (618 patients), performed by four surgeons in a single institution [1/2/2018-10/23/2018]. Based on effective date of the law, cases were divided into: prelaw (327 cases; 168 hips/159 knees) and postlaw (331 cases; 191 hips/140 knees) phases. Baseline demographics and surgical characteristics were compared. The effect of the law on perioperative outcomes: length of stay, complications, emergency department/office visits, patient phone calls, reoperation or readmission (90 days), and total morphine equivalents prescribed was investigated. Independent sample t-tests and chi-square analyses were performed., Results: Prelaw and postlaw phases had no significant difference in baseline demographics and characteristics. No difference was found in length of stay. Opioid law implementation led to significantly lower total oral morphine equivalents after TJAs [Prelaw: 1059.9 ± 825.4 vs postlaw: 942.8 ± 691.7; P = .04], but did not result in a significant increase in 90-day complications, patient visits (office or emergency) or phone calls, and reoperation or readmission., Conclusion: Our data suggest that Florida state opioid prescription limiting law has resulted in a marked decline in opioid prescription without any increase in rates of patient visits, phone calls, or readmission after TJA., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Inflammatory markers such as the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels have always been a part of the diagnostic criteria for periprosthetic joint infection (PJI), but they perform poorly anticipating the outcome of reimplantation. D-dimer has been reported in a small series as a potential marker to measure infection control after single-stage revisions to treat PJI. Nonetheless, its use to confirm infection control and decide the proper timing of reimplantation remains uncertain., Questions/purposes: (1) What is the best diagnostic threshold and accuracy values for plasma D-dimer levels compared with other inflammatory markers (ESR and CRP) or what varying combinations of these tests are associated with persistent infection after reimplantation? (2) Do D-dimer values above this threshold, ESR, CRP, and varying test combinations at the time of reimplantation indicate an increased risk of subsequent persistent infection after reimplantation?, Methods: We retrospectively studied the electronic medical records of all 53 patients who had two-stage revisions for PJI and who underwent plasma D-dimer testing before reimplantation at one of two academic institutions from November 22, 2017 to December 5, 2020. During that period, all patients undergoing two-stage revisions also had a D-dimer test drawn. The minimum follow-up duration was 1 year. We are reporting at this early interval (rather than the more typical 2-year time point) because of the poorer-than-expected performance of this diagnostic test. Of these 53 patients, 17% (9) were lost to follow-up before 1 year and could not be analyzed; the remaining 44 patients (17 hips and 27 knees) were studied here. The mean follow-up was 503 ± 135 days. Absence or persistence of infection after reimplantation were defined according to the Delphi criteria. The conditions included in these criteria were: (1) control of infection, as characterized by a healed wound without fistula, drainage, or pain; (2) no subsequent surgical intervention owing to infection after reimplantation; and (3) no occurrence of PJI-related mortality. The absence of any of the aforementioned conditions until the final follow-up examination was deemed a persistent infection after reimplantation. Baseline patient characteristics were not different between patients with persistent infection (n = 10) and those with absence of it after reimplantation (n = 34) as per the Delphi criteria. Baseline patient characteristics evaluated were age, gender, self-reported race (white/Black/other) or ethnicity (nonHispanic/Hispanic), BMI, American Society of Anesthesiologists (ASA) status, smoking status(smoker/nonsmoker), and joint type (hip/knee). The optimal D-dimer threshold to differentiate between persistence of infection or not after reimplantation was calculated using the Youden index. A receiver operating characteristic curve analysis was performed to test the accuracy of D-dimer, ESR, CRP, and their combinations to establish associations, if any, with persistent infection after reimplantation. A Kaplan-Meier survival analysis (free of infection after reimplantation) with a log-rank test was performed to investigate if D-dimer, ESR, and CRP were associated with absence of infection after reimplantation. Survival or being free of infection after reimplantation was determined as per Delphi criteria. Alpha was set at p < 0.05., Results: In the receiver operating characteristic curve analysis, with an area under the curve of 0.62, D-dimer showed low accuracy and did not anticipate persistent infection after reimplantation. The optimal D-dimer threshold differentiating between persistence of infection or not after reimplantation was 3070 ng/mL. When using this threshold, D-dimer demonstrated a sensitivity of 90% (95% CI 55.5% to 99.7%) and negative predictive value of 94% (95% CI 70.7% to 99.1%), but low specificity (47% [95% CI 29.8% to 64.9%]) and positive predictive value (33% [95% CI 25.5% to 42.2%]). Although D-dimer showed the highest sensitivity, the combination of D-dimer with ESR and CRP showed the highest specificity (91% [95% CI 75.6% to 98%]) defining the persistence of infection after reimplantation. Based on plasma D-dimer levels, with the numbers available, there was no difference in survival free from infection after reimplantation (Kaplan-Meier survivorship free from infection at minimum 1 year in patients with D-dimer below 3070 ng/mL versus survivorship free from infection with D-dimer above 3070 ng/mL: 749 days [95% CI 665 to 833 days] versus 615 days [95% CI 471 to 759 days]; p = 0.052). Likewise, there were no associations between high ESR and CRP levels and persistent infection after reimplantation, but the number of events was very small, and insufficient power is a concern with this analysis., Conclusion: In this preliminary series, with the numbers available, D-dimer alone had poor accuracy and was not associated with survival free from infection after reimplantation in patients who underwent two-stage exchange arthroplasty. D-dimer alone might be used to establish that PJI is unlikely, and the combination of D-dimer, ESR, and CRP should be considered to confirm PJI diagnosis in the setting of reimplantation.Level of Evidence Level IV, diagnostic study., Competing Interests: Each author certifies that neither he, nor any member of his immediate family, has funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request., (Copyright © 2021 by the Association of Bone and Joint Surgeons.)

Multiple threshold values have been proposed for synovial leukocyte count (white blood cell count) and synovial neutrophil percentage (percent polymorphonuclear neutrophils) in the diagnosis of periprosthetic joint infection (PJI). The objective of this study was to elucidate the variability of these criteria under diverse patient/surgical settings. Hip PJIs yield higher synovial white blood cell counts and percent polymorphonuclear neutrophils than knee PJIs. Periprosthetic joint infection of failed unicompartmental knee arthroplasty produces a higher white blood cell count than that of failed total knee arthroplasty. Synovial white blood cell count and percent polymorpho-nuclear neutrophils PJI thresholds also vary in patients with antibiotic cement spacers and depend on the timing from primary arthroplasty (<6 weeks vs >6 weeks). Similarly, test results should be carefully interpreted for patients with comorbidities so that PJI is not missed or falsely identified. [ Orthopedics . 2021;44(3):e320-e325.].

Study Design: Retrospective single-center study., Objective: Investigate the effect of posterior instrumentation on the relationship between lordosis and kyphosis., Methods: Surgically treated patients with a minimum of 6 months of follow-up were analyzed. Asymptomatic volunteers served to show the normal anatomical relationship between thoracic and lumbar curves. Patients were stratified based on postoperative instrumentation: "Thoracic Fusion" = complete fusion of thoracic spine; "Lumbar Fusion" = complete fusion of lumbar spine; and "Complete Fusion" = fusion from sacrum to at least T5. Bivariate correlations and regression analysis were used to evaluate the relationship between change in thoracic kyphosis (ΔTK) and change in spinopelvic mismatch (ΔPI-LL; pelvic incidence-lumbar lordosis) before and after fusion. Analyses were repeated in "Lumbar Fusion" patients with flexible preoperative thoracic spines., Results: For asymptomatic volunteers, the natural anatomical relationship between TK and LL was found to be TK = 41% of LL ( r = 0.425, P < .001). A total of 153 of 167 adult spinal deformity patients were included (62 years old, 26.7 kg/m 2 , 78% female). Mean follow-up was 11.5 ± 6.8 months. "Thoracic Fusion" group showed no alteration in the natural relationship between TK and LL (ΔTK = 39% ΔPI-LL), whereas "Lumbar Fusion" group had a reduction in reciprocal change (ΔTK = 34% ΔPI-LL) although a subanalysis of patients in the "Lumbar Fusion" group with flexible thoracic spines showed a marked compensation in reciprocal change with (ΔTK = 58% ΔPI-LL)., Conclusion: The relationship between ΔTK and ΔPI-LL is dependent on level instrumented. "Thoracic Fusion" drives change in LL while this relationship is affected by TK's natural stiffness in "Lumbar Fusion" patients.

Background: Although periprosthetic fractures are increasing in prevalence, evidence-based guidelines for the optimal treatment of periprosthetic tibial fractures (PTx) are lacking. Thus, the purpose of this study is to assess the clinical outcomes in PTx after a total knee arthroplasty (TKA) which were treated with different treatment options., Methods: A retrospective review was performed on a consecutive series of 34 nontumor patients treated at 2 academic institutions who experienced a PTx after TKA (2008-2016). Felix classification was used to classify fractures (Felix = I-II-III; subgroup = A-B-C) which were treated by closed reduction, open reduction/internal fixation, revision TKA, or proximal tibial replacement. Patient demographics and surgical characteristics were collected. Failure of treatment was defined as any revision or reoperation. Independent t-tests, one-way analysis of variance, chi-squared analyses, and Fisher's exact tests were conducted., Results: Patients with Felix I had more nonsurgical complications when compared to Felix III patients (P = .006). Felix I group developed more postoperative anemia requiring transfusion than Felix III group (P = .009). All fracture types had >30% revision and >50% readmission rate with infection being the most common cause. These did not differ between Felix fracture types. Patients who underwent proximal tibial replacement had higher rate of postoperative infection (P = .030), revision surgery (P = .046), and required more flap reconstructions (P = .005)., Conclusion: PTx after a TKA is associated with high revision and readmission rates. Patients with Felix type I fractures are at higher risk of postoperative nonsurgical complications and anemia requiring transfusion. Fractures treated with proximal tibial replacement are more likely to develop postoperative infections and undergo revision surgery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Case: A patient with Aitken type A proximal focal femoral deficiency (PFFD) and significant limb length discrepancy managed with total hip arthroplasty making use of a novel technique that features a direct anterior approach (DAA) and a subtrochanteric shortening osteotomy., Conclusion: Although the current description of the shortening osteotomy is for PFFD, it is versatile enough to allow its application in other hip pathologies requiring subtrochanteric shortening in the setting of total hip arthroplasty. The authors believe that the description of this case report and surgical technique may be an option for the experienced DAA surgeon., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B393)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Extensor mechanism disruption following total knee arthroplasty (TKA) is a devastating complication that causes high failure rates. There is controversy on what is the best way to do an extensor mechanism reconstruction. This study aims to compare both allograft and synthetic reconstructive techniques for success, reoperation, and infection rates and functional outcomes. The search on PubMed, MEDLINE, Embase, BIOSIS, and Cochrane databases was performed on March 15, 2019, using the following keyword groups: (1) "extensor mechanism" and "total knee arthroplasty," (2) "extensor mechanism" and "knee arthroplasty," (3) "extensor mechanism" and "revision total knee arthroplasty," and (4) "extensor mechanism" and "revision knee arthroplasty". Only studies on extensor mechanism disruption after TKA that included sufficient data to compare these two surgical techniques were included. Meta-analysis was performed with random effect model using the DerSimonian-Laird method. Thirty studies were included. The overall success rate of the reconstruction was 73.3% (95% confidence interval [CI]: 0. 651, 0.814). The success rate of allograft (72.8%, 95% CI: 0.626, 0.829) was not significantly different from synthetic material (78%, 95% CI: 0.707, 0.852, p  = 0.416). There was no significant difference in revision rates between allograft (14.2%, 95% CI: 0.095, 0.189) and synthetic material (16%, 95% CI: 0.096, 0.223, p  = 0.657). The overall relative risk of infection was 4.301 (95% CI: 1.885, 9.810). There was no significant difference in relative risk of infection between allograft (3.886, 95% CI: 1.269, 11.903) and synthetic material (4.851, 95% CI: 1.433, 16.419, p  = 0.793). No statistically significant difference was found in mean postoperative Knee Society score (73.109 [95% CI: 67.296, 78.922] vs. 72.679 [95% CI: 69.184, 76.173], p  = 0.901) between allograft and mesh reconstruction groups. There were no significant differences in overall failures, infections, functional outcomes, or revision reconstructions between allograft and synthetic material extensor mechanism reconstructions. Our results demonstrate the difficulty in treating this serious injury, independent of technique, as well as the significant risk for overall failure and infection., Competing Interests: C.A.H. reports grants and personal fees from Zimmer, grants from Stryker, other from PSI, grants from Orthofix, Inc., grants from OREF, grants and personal fees from KCI, grants from Cymedica, grants from CD Diagnostics, grants from Ferring Pharmaceuticals, grants from Orthogenics, outside the submitted work; and American Association of Hip and Knee Surgeons: Board or committee member; American Journal of Orthopedics: Editorial or governing board; Journal of Arthroplasty: Editorial or governing board; Journal of Hip Surgery: Editorial or governing board; Journal of Knee Surgery: Editorial or governing board; Mid-American Orthopaedic Association: Board or committee member; Musculoskeletal Infection Society: Board or committee member. M.E. reports other from Stryker, outside the submitted work. All other authors reported no conflict of interest., (Thieme. All rights reserved.)

Background: There is scarce literature describing pathogens responsible for periprosthetic joint infections (PJIs) around the world. Therefore, we sought to describe periprosthetic joint infection causative organisms, rates of resistant organisms, and polymicrobial infections at 7 large institutions located in North/South America and Europe., Methods: We performed a retrospective study of 654 periprosthetic hip (n = 361) and knee (n = 293) infections (January 2006 to October 2019) identified at Cleveland Clinic Ohio/Florida in the United States (US) (n = 159), Hospital Italiano de Buenos Aires in Argentina (n = 99), Hospital Asociación Española in Uruguay (n = 130), Guy's and St Thomas' Hospital in the United Kingdom (UK) (n = 103), HELIOS Klinikum in Germany (n = 59), and Vreden Institute for Orthopedics in St. Petersburg, Russia (n = 104). Analyses were performed for the entire cohort, knees, and hips. Alpha was set at 0.05., Results: Overall, the most frequent organisms identified were Staphylococcus aureus (24.8%) and Staphylococcus epidermidis (21.7%). The incidence of organisms resistant to at least one antibiotic was 58% and there was a significant difference between hips (62.3%) and knees (52.6%) (P = .014). Rates of resistant organisms among countries were 37.7% (US), 66.7% (Argentina), 71.5% (Uruguay), 40.8% (UK), 62.7% (Germany), and 77.9% (Russia) (P < .001). The overall incidence of polymicrobial infections was 9.3% and the rates across nations were 9.4% in the US, 11.1% in Argentina, 4.6% in Uruguay, 4.9% in UK, 11.9% in Germany, and 16.3% in Russia (P = .026)., Conclusion: In the evaluated institutions, S aureus and S epidermidis accounted for almost 50% of all infections. The US and the UK had the lowest incidence of resistant organisms while Germany and Russia had the highest. The UK and Uruguay had the lowest rates of polymicrobial infections., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Periprosthetic joint infection (PJI) is one of the most dreadful complications after THA and TKA. Though prevention is of utmost importance in PJI management, the last decade has seen many remarkable developments in PJI diagnosis, including the introduction of several standardized PJI diagnostic definitions and biomarkers. Depending on the specific clinical situation, a myriad of treatment options for PJI are offered. Our review aims to summarize the pertinent information on PJI diagnosis and synthesize literature on the different treatment methods currently used in clinical practice. One of the most accepted PJI diagnostic definitions was developed by the Musculoskeletal Infection Society (MSIS) in 2011, later modified in the 2013 International Consensus Meeting (ICM). After promising results from studies, alpha-defensins and D-dimer were recently incorporated into the 2018 ICM PJI definition. The management choices for PJI include irrigation and debridement (DAIR), one-stage exchange arthroplasty, or two-stage exchange arthroplasty, to name a few. While two-stage revision has traditionally been the treatment of choice in the United States, there has been a growing body of evidence framing one-stage revision as a comparable choice. One-stage revision should be offered in patients meeting strict selection criteria: no sinus tract, proper soft tissue available for wound closure, appropriate bone stock, a favorable identifiable organism with encouraging antibiotic sensitivities (for cement and oral suppression later), and robust immunological status. DAIR can be considered in case of early infections with sensitive infecting organisms. Patients with multiple unsuccessful revisions or those who refuse further surgical intervention for PJI can be offered antibiotic suppression. If nothing seems to work, salvage procedures (resection arthroplasty and arthrodesis) are available as a last resort. Further research is encouraged to improve on diagnostic capabilities and develop evidence on the best treatment of choice for PJI., (© The Authors, published by EDP Sciences, 2021.)

Background: The optimal timing of the second surgery in primary staged bilateral total hip/knee arthroplasty remains uncertain. Perioperative hospital adverse events represent a significant issue, even "minor events" lead to substantial costs in workup tests, interconsultations, and/or increased hospital length-of-stay (LOS). Therefore, we sought to ascertain whether the timing of the second arthroplasty affects perioperative outcomes and/or rates of adverse events., Methods: We retrospectively reviewed a consecutive series of 670 primary staged bilateral total hip/knee arthroplasty performed by 2 surgeons (2010-2016) at a single institution. The days between both arthroplasties were calculated for each pair of hips or knees. We evaluated demographics and LOS, discharge disposition, adverse events (ie, nausea, pulmonary embolism), and transfusion rates. The second arthroplasties (n = 335) were set apart in 2 groups based on the time they were done with respect to their corresponding contralateral first arthroplasty using 3 different thresholds: (1) ≤90 vs >90 days, (2) ≤180 vs >180 days, and (3) ≤365 vs >365 days., Results: No significant differences in outcome comparisons were observed using either 90 or 180 days thresholds. However, using the 365 days thresholds, the mean LOS (2.21 vs 1.92 days, P = .015), adverse event (26% vs 15.3%, P = .021), total transfusion (7.4% vs 1.5%, P = .020), and allogeneic transfusion (6.9% vs 1.5%, P = .033) rates were significantly higher in second arthroplasties performed at or less than 1 year apart from the first, respectively., Conclusion: Staging the second arthroplasty more than a year apart from the first one seems to offer better LOS and rates of hospital adverse events, transfusions. However, unless patients are willing to wait a year between surgeries, our data also suggest no increased risk in regards to adverse events when proceeding before or after 90/180 days., Level of Evidence: Level III., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: There is scarce and contradicting evidence supporting the use of serum d-dimer for the diagnosis of periprosthetic joint infection in revision total hip (THA) and knee (TKA) arthroplasty. Therefore, the purpose of this study is to test the accuracy of serum d-dimer against the 2013 International Consensus Meeting (ICM) criteria., Methods: A retrospective review was performed on a consecutive series of 172 revision THA/TKA surgeries performed by 3 fellowship-trained surgeons at a single institution (August 2017 to May 2019) and that had d-dimer performed during their preoperative workup. Of this cohort, 111 (42 THAs/69 TKAs) cases had complete 2013 ICM criteria tests and were included in the final analysis. Septic and aseptic revisions were categorized per 2013 ICM criteria ("gold standard") and compared against serum d-dimer using an established threshold (850 ng/mL). Sensitivity, specificity, likelihood ratios, and positive/negative predictive values were determined. Independent t-tests, Fisher's exact tests, chi-squared tests, and receiver operating characteristic curve analysis were performed., Results: There was no statistically significant difference in baseline demographics between septic and aseptic cases per 2013 ICM criteria. When compared to ICM criteria, d-dimer demonstrated high sensitivity (95.9%) and negative predictive value (90.9%) but low specificity (32.3%), positive predictive value (52.8%), and overall, poor accuracy (61%) to diagnose periprosthetic joint infection. Positive likelihood ratio was 1.42 while negative likelihood ratio was 0.13. The area under the curve (AUC) was 0.742., Conclusion: Serum d-dimer has poor accuracy to discriminate between septic and aseptic cases using a described threshold in the setting of revision THA and TKA., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction : Periprosthetic joint infection (PJI) remains one of the most dreaded and challenging complications in adult reconstruction. While primary total joint arthroplasty is one of the most successful surgeries in medicine, revisions secondary to infections do not hold as well. As the number of primary procedures increases, so will infections. In North America, two-stage exchange arthroplasty is the standard of care for patients with PJI, especially when the presentation is greater than 4 weeks after the index procedure. However, it is not necessarily the best option for all patients, particularly when compared to one-stage arthroplasty. Areas covered : The aim of this review is to analyze the indications, safety, and efficacy of two-stage exchange arthroplasty for the treatment of PJI and to compare the results reported 10 years ago with the ones of recent publications and those of one-stage arthroplasty. Expert opinion : Two-stage exchange arthroplasty is a safe and efficacious treatment particularly suited for recalcitrant infections, resistant organisms, and patients with certain host factors that make it more difficult to eradicate infection. However, one-stage arthroplasty might be well suited as well for infections caused by susceptible organisms and patients with minimal or no comorbidities or those unable to undergo two surgeries.

Background: Perioperative hospital adverse events represent a significant outcome that is often overlooked. Even "minor events" such as fever or tachycardia may lead to significant costs due to workup tests, interconsultations, and/or increased length of stay (LOS). The optimal timing of bilateral direct anterior approach total hip arthroplasty (DAA-THA) remains unsettled. Consequently, we wanted to compare hospital LOS, discharge disposition, hospital adverse events (major and minor), and transfusion rates between simultaneous and staged bilateral DAA-THA., Methods: A retrospective chart review was conducted on a consecutive series of 347 primary bilateral DAA-THAs (204 patients) performed by 2 surgeons in a single institution (2010-2016). The hips finally included were categorized as simultaneous (Sim-n = 61), staged 1 (Stg1-n = 143), or staged 2 (Stg2-n = 143). We also compared simultaneous with staged surgeries performed ≤1 and >1 year apart. Baseline demographics, LOS, discharge disposition, hospital adverse events, and transfusions were assessed., Results: The simultaneous group had significantly younger patients and a higher proportion of males when compared with the staged groups and showed significant longer LOS [2.61 (Sim) vs 2.06 (Stg1) vs 1.63 (Stg2) days, P < .001], lower proportion of home discharge [77% (Sim) vs 91.6% (Stg1) vs 96.5% (Stg2), P < .001], as well as higher (overall) rate of adverse events [31.1% (Sim) vs 28.7% (Stg1) vs 14.0% (Stg2), P = .003] and transfusions [45.9% (Sim) vs 6.3% (Stg1) vs 7.0% (Stg2), P < .001]. However, most transfusions were autologous [37.7% (Sim) vs 3.5% (Stg1) vs 0% (Stg2), P < .001]., Conclusion: Our data show that bilateral DAA-THAs performed in a staged fashion, rather than simultaneously, have a shorter hospital LOS and decreased rates of adverse events and overall transfusions. Notwithstanding, simultaneous surgery should still be considered an option in selected patients., Level of Evidence: Level III., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Various definitions and biomarkers have been developed in an unsuccessful attempt to obtain a "gold standard" for periprosthetic joint infection (PJI) diagnosis. The development of the 2011 Musculoskeletal Infection Society criteria facilitated further research and advances by allowing the use of a consistent PJI definition across studies. The newly proposed 2018 criteria do not rely at all on expert opinions/consensus. In this review, we describe the most relevant definitions developed throughout recent time, their rationale, characteristics, and supportive evidence for their clinical implementation. In the opinion of the authors, the orthopedic community should consider a probability and likelihood paradigm to create a PJI diagnostic definition. Probably not a single definition might be suited for all situations; the inclusion of serological findings could be the next step moving forward., (Copyright © 2019. Published by Elsevier Inc.)

Periprosthetic joint infection (PJI) continues to impact a remarkable number of patients who undergo total knee arthroplasty (2.0-2.1%). Substantial efforts to curtail these rates have been seen in the past decade including various attempts to reach a clear definition of PJI that the orthopaedic community could adopt as a gold standard. The Musculoskeletal Infection Society (MSIS) criteria, slightly modified by the International Consensus Meeting (ICM), has gained widespread acceptance and it is a step closer to that goal. Research on markers such as serum cross-linked D-fragments (D-dimer) seems promising in the diagnosis of infection. In the setting of PJI, a recent publication has established a threshold of 850 ng/mL as the optimal cutoff value for serum D-dimer. Therefore, our objective is to present a summary of the current literature on the changing indications of D-dimer and its rising importance in the setting of PJI. Serum D-dimer has been shown to outperform other conventional tests such as erythrocyte sedimentation rate and C-reactive protein that have been a major part of the ICM criteria and it has been included in the newly proposed diagnostic criteria for PJI that correctly diagnoses infection in 95.5% of septic patients (overall sensitivity: 97.7%, specificity: 99.5%). In comparison with the ICM and MSIS infection definitions, the new criteria revealed a higher sensitivity (97.7 vs. 86.9% and 97.7 vs. 79.3%, respectively), while specificity was similar. In conclusion, high D-dimer levels in primary or revision knee arthroplasty seem indicative of diagnosis of PJI. However, future studies are warranted to conclusively support the routine use of this marker and to validate the performance of the newly developed PJI diagnostic criteria under different clinical scenarios., Competing Interests: W.K.B. reports grants and personal fees from Zimmer, grants from Third Frontier, grants, personal fees and nonfinancial support from Thieme, grants and personal fees from Stryker, personal fees from Shukla Medical, personal fees and other from Peerwell, grants from Orthosensor, grants from NIH, personal fees from Exactech, Inc, grants from DJO, Inc., other from Custom Orthopaedic Solutions, other from Capsico Health, grants from Orthosensor, outside the submitted work; and Editor-in-Chief—Journal of Hip Surgery: Editorial or governing board. P.D.P. reports personal fees from Stryker, outside the submitted work. C.A.H.-R. reports grants and personal fees from Zimmer, grants from Stryker, other from PSI, grants from Orthofix, Inc., grants from OREF, grants and personal fees from KCI, grants from Cymedica, grants from CD Diagnostics, grants from Ferring Pharmaceuticals, outside the submitted work; and American Association of Hip and Knee Surgeons: Board or committee member—American Journal of Orthopedics: Editorial or governing board—Journal of Hip Surgery: Editorial or governing board—Journal of Knee Surgery: Editorial or governing board —American Orthopaedic Association: Board or committee member—Musculoskeletal Infection Society: Board or committee member., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

The risk of surgical site infection in primary total knee arthroplasty (TKA) has been reduced with the use of prophylactic antibiotics. First or second generation cephalosporins are still recommended as the primary prophylactic choice, but with the rise in the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, evidence has emerged in favor of using dual antibiotics including vancomycin. However, it is unclear whether these combinations of antibiotic regimens further reduce postoperative infection rates. As a result, the objective of this review is to summarize the current literature concerning the use of dual prophylactic antibiotics in TKA. The most common dual prophylactic antibiotic combination is cefazolin (C) and vancomycin (V). In general, when comparing the effectiveness of single versus dual antibiotics, conflicting results have been reported. Three studies demonstrated no substantial decrease in overall postoperative infection rates with the use of dual antibiotics when compared with cefazolin alone. One found a significant decrease only in MRSA infection rates when using cefazolin and vancomycin (CV) (0.8% C alone vs. 0.08% CV, p  < 0.05). Another investigation evaluated revision TKA patients who had combined cefazolin and vancomycin prophylaxis and showed a significant decline in both overall infection (7.89% [C] vs. 3.13% [CV]) and MRSA infection rates (4.21% [C] vs. 0.89% [CV]; p  < 0.05). Concerning the safety profile of dual antibiotics, particular precautions must be adopted with the use of vancomycin because of the risk of acute kidney injury. Instead of vancomycin, an alternate less nephrotoxic antibiotic option might be teicoplanin. Unfortunately, this latter agent is only available outside of the United States. In conclusion, the value of dual antibiotic prophylaxis for the prevention of periprosthetic knee infections remains unclear primarily because all comparative studies performed between dual and single antibiotics have been of low evidence with retrospective designs. Larger multicenter randomized controlled trials are warranted., Competing Interests: P.D.P. reports personal fees from Stryker, outside the submitted work. M.A.M. reports personal fees and nonfinancial support from Wolters Kluwer Health, other from USMI, personal fees and nonfinancial support from Up-to Date, grants and personal fees from TissueGene, grants and personal fees from Stryker, personal fees from Skye Biologics, personal fees from Pfizer, personal fees from Performance Dynamics, personal fees and other from Peerwell, personal fees from Pacira, grants and personal fees from Orthosensor, grants and personal fees from Ongoing Care Solutions, grants from National Institutes of Health (NIAMS and NICHD), personal fees from Microport, personal fees and nonfinancial support from Medicus Works LLC, grants and personal fees from Johnson & Johnson, personal fees from Flexion Therapeutics, grants and personal fees from DJ Orthopaedics, personal fees from Cymedica, outside the submitted work; and AAOS: Board or Committee Member of American Association of Hip and Knee Surgeons: Board or Committee Member Journal of Arthroplasty: Editorial or Governing Board Journal of Knee Surgery: Editorial or Governing Board Knee Society: Board or Committee Member of Orthopedics: Editorial or Governing Board Surgical Techniques International: Editorial or governing board. C.A.H.-R. reports grants and personal fees from Zimmer, grants from Stryker, other from PSI, grants from Orthofix, Inc., grants from OREF, grants and personal fees from KCI, grants from Cymedica, grants from CD Diagnostics, grants from Ferring Pharmaceuticals, outside the submitted work; and American Association of Hip and Knee Surgeons: Board or Committee Member of American Journal of Orthopedics: Editorial or Governing Board Journal of Hip Surgery: Editorial or governing Board Journal of Knee Surgery: Editorial or Governing board-American Orthopaedic Association: Board or Committee Member of Musculoskeletal Infection Society: Board or Committee member., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Uranium isotopes have always been problematic to mankind since many centuries. Different studies all over the world have been unable to reveal causal relationship between uranium and its toxic effects on kidneys, bone and lungs. In this case report, we present a rare association of uranium toxicity with renal dysfunction and possibility of induction of osteosarcoma by an unknown mechanism. The presentation of the 12-year-old patient was reduction in urine output along with joint pains, seemed like that of diabetes mellitus, as he was already on insulin. The patient later diagnosed to have uranium toxicity. This case is an instance of strong association between medicine and public health. With complete history, physical examination and required investigations, all common causes like NSAID toxicity, aminoglycoside toxicity and exacerbation of diabetes were ruled out. Uranium investigations were done lastly based on the toxicology report of drinking water (South African toxicologist, Caron Smith). In the management strategy, the new regimen CBMIDA, supported by studies in Europe, was used. However, to our surprise, joint symptoms tracked their way to a diagnosis of osteosarcoma, which was later operated upon by our orthopaedic surgery team. Histopathologically, it was found to be a chondroblastic type of osteosarcoma.