Mini-open Femoroacetabular Osteoplasty in Patients With Tönnis Grade 2 or Higher Osteoarthritis is Associated With a Higher Risk of Subsequent Conversion to THA.

BACKGROUND: The severity of degenerative changes of the hip is known to adversely impact the outcomes of the treatment of femoroacetabular impingement (FAI). Although the operative indications for FAI have expanded to include patients with moderate degrees of hip osteoarthritis, the exact stage of hip osteoarthritis at which surgery for FAI can offer clinical benefits is still uncertain. QUESTIONS/PURPOSES: (1) How does the survivorship free from conversion to THA and survivorship free from revision differ between patients with preexisting Tönnis Grades 2 or 3 changes and those without advanced degenerative changes (Tönnis Grade 0 or 1) after mini-open femoroacetabular osteoplasty? (2) What are the differences in hip-specific and general-health outcome scores between the two groups after mini-open femoroacetabular osteoplasty? METHODS: From December 2003 to April 2019, we treated 901 patients for FAI, and their clinical data were systematically recorded in a longitudinally maintained database. Mini-open femoroacetabular osteoplasty was our preferred surgical approach because of the surgeon's extensive experience with the technique. Among the entire dataset, 6% of patients (51 individuals) had Tönnis Grade 2 or higher hip osteoarthritis, while the remaining 94% (850 patients) had no or mild degenerative changes (Tönnis Grade 0 or 1). In the Tönnis Grade 2 or 3 group, three patients were lost before the minimum 2-year follow-up duration, leaving 4% (48 patients) who qualified for inclusion in the study. For the matched group with Tönnis Grade 0 or 1, 5% (45 patients) were excluded because of incomplete data, and a further 7% (58 patients) were excluded because they did not have 2 years of follow-up, leaving 83% (747 patients) who were eligible for the matching process. Matching was based on patient age (within 1 year), gender, and BMI (within one unit). Matching resulted in the inclusion of 144 randomly selected control patients in this retrospective, comparative study. General indications for femoroacetabular osteoplasty included symptoms of pain and restricted hip motion in young, active patients with signs of FAI evident on physical examination and radiographs. Patient demographics, medical history, radiographic parameters, and intraoperative findings were compared between the two groups to establish baseline differences and identify potential confounding variables. There was no difference in the mean ± standard deviation age between the cohort of interest and control group (39 ± 10 years and 38 ± 11 years, respectively; p = 0.67). There was no difference in the mean follow-up duration (7 ± 3 years versus 8 ± 2 years; p = 0.25) or the preoperative symptomatic period between the study and control groups (2 ± 2 years versus 3 ± 6 years; p = 0.09). There was no difference in the prevalence of dysplasia, slipped capital femoral epiphysis, Perthes disease, or avascular necrosis of the hip between the two groups. Intraoperatively, the groups did not differ in terms of labral repair (65% [31 of 48] versus 78% [113 of 144]; p = 0.08) and labral transplantation (2%; p > 0.99 for both); however, labral resection was performed more frequently in the study group (63% [30 of 48] versus 42% [60 of 144]; p = 0.002). At a minimum of 2 years of follow-up, survivorship free from conversion to THA and survivorship free from revision surgeries, as well as the latest clinical and functional outcome scores (SF-36, Hip Disability and Osteoarthritis Outcome Score, and modified Harris hip score), were compared between groups. RESULTS: Survivorship free from conversion to THA at 5 years was lower among patients with preexisting Tönnis Grades 2 or 3 changes than it was among patients matched for age, gender, and BMI who did not have advanced degenerative changes (Tönnis Grade 0 or 1) after mini-open femoroacetabular osteoplasty (75% [95% confidence interval 64% to 88%] versus 92% [95% CI 87% to 96%]; p < 0.001). No patients in either group underwent reoperation other than conversion to THA. Although the groups did not differ at baseline in terms of their outcomes scores, the group with more visible arthritis had lower postoperative Hip Disability and Osteoarthritis Outcome Scores than the control group (60 ± 21 points versus 86 ± 11 points, mean difference 26 points [95% CI 10 to 41]; p =0.004). There were no other between-group differences in outcome scores after surgery. CONCLUSION: In our study, approximately 25% of patients undergoing mini-open femoroacetabular osteoplasty with Tönnis Grade 2 or higher osteoarthritis underwent conversion to THA within 5 years. Some postoperative functional scores were lower in patients with advanced arthritis than in matched patients with no or mild arthritis. We emphasize the importance of exercising caution when considering femoroacetabular osteoplasty in patients in whom advanced arthritis is already evident at the time of presentation. LEVEL OF EVIDENCE: Level III, therapeutic study.

Comprehensive Guidance for the Prevention of Periprosthetic Joint Infection After Total Joint Arthroplasty and Pitfalls in the Prevention.

Total joint arthroplasty (TJA) is a surgical procedure, in which parts of damaged joints are removed and replaced with a prosthesis. The main indication of TJA is osteoarthritis, and the volume of TJA is rising annually along with the increase of aged population. Hip and knee are the most common joints, in which TJAs are performed. The TJA prosthesis is composed of metal, plastic, or ceramic device. Even though TJA is the most successful treatment for end-stage osteoarthritis, it is associated with various complications, and periprosthetic joint infection (PJI) is the most serious complication after TJA. With the increasing volume of TJAs, there is a simultaneous rise in the incidence of PJI. Contamination of the surgical wound and the adherence of bacteria to the surface of prosthetic component represent the initial step in the pathogenesis of PJI. The main sources of the contamination are 1) patient's own flora, 2) droplets in the operation room air, and 3) surgical gloves and instruments. Even though modern techniques have markedly reduced the degree of contamination, TJAs cannot be done in completely germ-free conditions and some degree of contamination is inevitable in all surgical procedures. However, not all contamination leads to PJI. It develops when the burden of contamination exceeds the immune threshold or the colony forming units (CFUs) and various factors contribute to a decrease in the CFU level. Surgeons should be aware of the germ burden/CFU concept and should monitor sources of contamination to maintain the germ burden below the CFU to prevent PJI.

Practice Management Strategies Among Current Members of the American Association of Hip and Knee Surgeons.

BACKGROUND: A survey was conducted at the 2023 Annual Meeting of the American Association of Hip and Knee Surgeons (AAHKS) to assess practice management strategies among current AAHKS members. METHODS: Members of AAHKS used an app to answer both multiple-choice and "yes or no" questions related to a variety of issues related to their practices. RESULTS: The number of AAHKS members in private practice (37%) continues to decline, and 4% are now in private equity-employed practices. Fee for service (30%) and relative value units (30%) are the major forms of compensation. The number of AAHKS members that perform total joint arthroplasties at ambulatory surgery centers continues to increase, and supply chain issues (91%) remain a problem. There has been a decrease in surgeon participation in bundled payment programs and gainsharing arrangements with hospitals. CONCLUSIONS: This member's survey provides valuable information regarding practice patterns. The shift to outpatient surgery has continued. Future surveys will be performed to monitor changes in practice patterns over time.

Gloves Contamination During Revision Surgery for Periprosthetic Joint Infection.

BACKGROUND: The use of double gloving has become a standard practice for joint replacement surgeons. However, since there are limited data on how gloves are contaminated during both primary and revision arthroplasty, no precise protocol exists to direct surgeons on when, or if, to change their gloves. The goals of this preliminary study were to evaluate the contamination of gloves during total joint arthroplasties (TJAs). METHODS: We included 25 infected cases and 10 primaries, which were performed at the same institution using the same surgical protocol from 3 fellowship trained surgeons. Samples were taken every 20 minutes from the start of the surgery until the joint was irrigated. Procedural steps were noted. To evaluate cross-contamination during infected cases, we sampled gloves using blood agar plates. In primary cases, culture swabs of anterior chamfer cuts and sterile instruments on the back table were used as negative controls. Next-generation sequencing (NGS) was used as an adjunct to identify low virulence bacteria. RESULTS: In the primary cases, all samples were found culture negative but 3 (8.1%) of the 37 samples were found to have a low, unidentifiable bacterial mass via NGS testing. In the infected cases, 41 (59.4%) of the 69 samples yielded positive microbial results. The positivity rate was higher in the samples collected after the arthrotomy was performed (70%) compared to samples collected before the arthrotomy was performed (40%), and the surgeon was only dissecting superficial layers (P = .502). CONCLUSION: Gloves seem to be a common source of cross-contamination in the intraoperative field during revision TJA. Due to the higher percent of positive samples following the opening of the joint, we hypothesize that the arthrotomy allows for the spread of bacteria across the operative site. While further investigation is necessary to formulate a precise protocol for the changing of gloves during TJA, it may be beneficial to perform a thorough irrigation of the joint and change of the gloves immediately following arthrotomy.

Operating Room Air May Harbor Pathogens: The Role of an Ultraviolet Air Filtration Unit.

BACKGROUND: One important factor for the prevention of surgical site infections is ultraclean air in the operating room (OR). Still, the direct sterilization potential of most technologies, especially in a dynamic clinical setting, is not well understood. We aimed to determine and compare the microbial presence from the inlet and outlet flow of a filtration unit with crystalline ultraviolet-C (C-UVC) light. METHODS: A prospective study was conducted at a single institution, where primary total joint arthroplasty and spine surgeries were performed. The OR was fitted with a positive ventilation system. In addition, a filtration unit with a C-UVC sterilizing light was placed in the OR. The inlet and outlet air flows were swabbed simultaneously and compared. Swabs were processed for culture and next-generation sequencing. RESULTS: The mean length of the surgical procedures sampled was 68 ± 13 minutes. Overall, 19 out of 200 (9.5%) swabs isolated microorganisms. Inlet air swabs were positive at a higher rate (16 versus 3%; P < .01) compared to the outlet air swabs. A wide variety of Gram-positive, Gram-negative, and anaerobic bacteria were isolated, but fungi were only recovered from inlet air swabs. The detection of microorganisms was also higher when more door openings were performed (32.5 ± 7.1 versus 27.9 ± 5.6; P < .01). CONCLUSIONS: Air swabs mainly isolated microorganisms from the inlet flow to the filtration unit with a C-UVC light. The sterilizing unit counteracted factors affecting the air quality in the OR, namely door openings, surgical personnel, and tissue combustion.

Neutrophil to Lymphocyte Ratio and Periprosthetic Joint Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) has shown promising results as a diagnostic tool for periprosthetic joint infection (PJI) after total joint arthroplasty. We conducted a systematic review and meta-analysis to determine the utility of NLR in the diagnosis of PJI. METHODS: We searched PubMed, Scopus, and Web of Science from inception up to 2022 and evaluated the quality of the included literature. RESULTS: Based on the 12 eligible studies, NLR levels were significantly higher in patients who had PJI compared to those who had aseptic loosening (standard mean difference (SMD) = 1.05, 95% Confidence Interval (CI) = 0.71 to 1.40, P < .001). In the subgroup analysis according to type of PJI, NLR levels were significantly higher in patients who had either acute (SMD = 1.04, 95% CI = 0.05 to 2.03, P < .001) or chronic PJI (SMD = 1.08, 95% CI = 0.55 to 1.61, P < .001), compared to those who had aseptic loosening. According to type of arthroplasty, NLR levels were significantly higher in patients who had either total knee arthroplasty (SMD = 1.81, 95% CI = 1.48 to 2.13, P < .001) or total hip arthroplasty (SMD = 1.76, 95% CI = 1.54 to 1.98, P < .001) compared to aseptic loosening. The pooled sensitivity of the 12 studies was 0.73 (95% CI, 0.65 to 0.79), and the pooled specificity was 0.75 (95% CI, 0.71 to 0.78). The pooled positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of NLR were 2.94 (95% CI = 2.44 to 3.54), 0.35 (95% CI = 0.27 to 0.46), and 8.26 (95% CI = 5.42 to 12.58), respectively. CONCLUSION: In summary, this meta-analysis indicates that NLR is a reliable marker in the diagnosis of PJI.

Finding the Optimal Screening Test for Periprosthetic Joint Infection: A Prospective Study.

BACKGROUND: No single test has demonstrated absolute accuracy in the diagnosis of periprosthetic joint infection (PJI). Serological markers are often used as screening tools to avoid unnecessary joint aspiration in cases with a low probability of infection. This study aimed to determine the utility of standard-of-care serological tests as a screening tool for PJI in patients undergoing revision arthroplasty. METHODS: This prospective study enrolled 502 patients undergoing revision hip or knee arthroplasty between May 2017 and August 2021. A PJI was defined using a modified definition of the 2018 International Consensus Meeting criteria. Plasma D-dimer, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fibrinogen were measured preoperatively. There were 82 patients undergoing reimplantation who were excluded. Additionally, 8 patients who had an inconclusive International Consensus Meeting score were also excluded. Of the 412 included patients, 317 (76.9%) underwent revision for aseptic failure, and 95 (23.1%) had PJI. Receiver operating characteristic curves were used to assess the diagnostic utility of each serological test. A pairwise comparison with Bonferroni correction was performed to determine whether the differences in areas under the curve (AUCs) between the tests were significant. Additional analyses were performed to find the threshold for each test that offered 100% sensitivity, allowing it to be the optimal screening test. RESULTS: All 4 serological markers, D-dimer (AUC 0.860, sensitivity 81.3%, specificity 81.7%), CRP (AUC 0.862, sensitivity 90.4%, specificity 70.0%), ESR (AUC 0.833, sensitivity 73.9%, specificity 85.2%), and fibrinogen (AUC 0.798, sensitivity 74.7%, specificity 75.4%), demonstrated comparable accuracy for the diagnosis of PJI (all P > .05). When maximizing sensitivity to 100%, D-dimer demonstrated the highest specificity (AUC 0.860, specificity 40.2%), outperforming ESR (AUC 0.833, specificity 3.3%), fibrinogen (AUC 0.798, specificity 2.3%), and CRP (AUC 0.862, specificity 0%). A plasma D-dimer level of ≥ 244 ng/mL was identified as the optimal cutoff for use as a screening test. CONCLUSIONS: Although plasma D-dimer demonstrated similar diagnostic accuracy as CRP, ESR, and fibrinogen, it outperformed all 3 aforementioned serological markers when used as a screening test for PJI. LEVEL OF EVIDENCE: Level II.

Commercial Synovial Antigen Testing is Inferior to Traditional Culture for the Diagnosis of Periprosthetic Joint Infection in Patients Undergoing Revision Total Knee Arthroplasty.

BACKGROUND: Despite its limitations, a culture remains the "gold standard" for pathogen identification in patients who have periprosthetic joint infection (PJI). Recently, a synovial fluid antigen test has been introduced by a commercial entity. The purpose of this multicenter study was to determine the accuracy of the antigen test in the diagnosis of PJI. METHODS: This retrospective study identified 613 patients undergoing revision total knee arthroplasty who had undergone preoperative synovial fluid analysis. A PJI was defined using the 2018 International Consensus Meeting (ICM) criteria. Patients who had an extended period (> 180 days) from aspiration to revision procedure (n = 62), those presenting within 90 days of their index arthroplasty procedure (n = 17), and patients who had an inconclusive ICM score (n = 8) were excluded. Using receiver operator characteristic curve analyses, we examined the utility of the microbial identification (MID) antigen test and any positive culture (either preoperative or intraoperative) in the diagnosis of PJI. RESULTS: A total of 526 patients were included. Of these, 125 (23.8%) were ICM positive and 401 (76.2%) were ICM negative. Culture demonstrated an area under the curve (AUC) of 0.864, sensitivity of 75.2%, and specificity of 97.5%. On the other hand, the MID test exhibited an AUC of 0.802, sensitivity of 61.6%, and specificity of 98.8%. The AUC of culture was significantly higher than that of the MID test (P = .037). The MID test was positive in 41.9% of culture-negative PJI cases. We also observed a high rate of discordance (29.7%) when both culture and the MID test were positive in the ICM-positive group. CONCLUSIONS: Synovial fluid antigen testing does not provide additional clinical benefit when compared to traditional cultures for the diagnosis of PJI. The antigen test had low sensitivity in the diagnosis of PJI and a relatively high rate of discordance with culture. LEVEL OF EVIDENCE: Level III.

International Delphi Study on Wound Closure and Dressing Management in Joint Arthroplasty: Part 1: Total Knee Arthroplasty.

BACKGROUND: The purpose of this modified Delphi study was to obtain consensus on wound closure and dressing management in total knee arthroplasty (TKA). METHODS: The Delphi panel included 20 orthopaedic surgeons from Europe and North America. There were 26 statements identified using a targeted literature review. Consensus was developed for the statements with up to three rounds of anonymous voting per topic. Panelists ranked their agreement with each statement on a five-point Likert scale. An a priori threshold of ≥ 75% was required for consensus. RESULTS: All 26 statements achieved consensus after three rounds of anonymous voting. Wound closure-related interventions that were recommended for use in TKA included: 1) closing in semi-flexion versus extension (superior range of motion); 2) using aspirin for venous thromboembolism prophylaxis over other agents (reduces wound complications); 3) barbed sutures over non-barbed sutures (lower wound complications, better cosmetic appearances, shorter closing times, and overall cost savings); 4) mesh-adhesives over other skin closure methods (lower wound complications, higher patient satisfaction scores, lower rates of readmission); 5) silver-impregnated dressings over standard dressings (lower wound complications, decreased infections, fewer dressing changes); 6) in high-risk patients, negative pressure wound therapy over other dressings (lower wound complications, decreased reoperations, fewer dressing changes); and 7) using triclosan-coated over non-antimicrobial-coated sutures (lower risks of surgical site infection). CONCLUSIONS: Using a modified Delphi approach, the panel achieved consensus on 26 statements pertaining to wound closure and dressing management in TKA. This study forms the basis for identifying critical evidence supported by clinical practice for wound management to help reduce variability, advance standardization, and ultimately improve outcomes during TKA. The results presented here can serve as the foundation for knowledge, education, and improved clinical outcomes for surgeons performing TKAs.

International Delphi Study on Wound Closure and Incision Management in Joint Arthroplasty Part 2: Total Hip Arthroplasty.

BACKGROUND: This modified Delphi study aimed to develop a consensus on optimal wound closure and incision management strategies for total hip arthroplasty (THA). Given the critical nature of wound care and incision management in influencing patient outcomes, this study sought to synthesize evidence-based best practices for wound care in THA procedures. METHODS: An international panel of 20 orthopedic surgeons from Europe, Canada, and the United States evaluated a targeted literature review of 18 statements (14 specific to THA and 4 related to both THA and total knee arthroplasty). There were 3 rounds of anonymous voting per topic using a modified 5-point Likert scale with a predetermined consensus threshold of ≥ 75% agreement necessary for a statement to be accepted. RESULTS: After 3 rounds of voting, consensus was achieved for all 18 statements. Notable recommendations for THA wound management included (1) the use of barbed sutures over non-barbed sutures (shorter closing times and overall cost savings); (2) the use of subcuticular sutures over skin staples (lower risk of superficial infections and higher patient preferences, but longer closing times); (3) the use of mesh-adhesives over silver-impregnated dressings (lower rate of wound complications); (4) for at-risk patients, the use of negative pressure wound therapy over other dressings (lower wound complications and reoperations, as well as fewer dressing changes); and (5) the use of triclosan-coated sutures (lower risk of surgical site infection) over standard sutures. CONCLUSIONS: Through a structured modified Delphi approach, a panel of 20 orthopedic surgeons reached consensus on all 18 statements pertaining to wound closure and incision management in THA. This study provides a foundational framework for establishing evidence-based best practices, aiming to reduce variability in patient outcomes and to enhance the overall quality of care in THA procedures.

Antibiotic-loaded cement in total joint arthroplasty: a comprehensive review.

This review evaluates the decision-making framework for using antibiotic-loaded cement (ALC) in the management of prosthetic joint infection (PJI). Drawing on available literature, we offer orthopaedic surgeons a guided discussion on several critical considerations. First, we explore the impact of antibiotic-loading on the mechanical properties of polymethylmethacrylate (PMMA) cement, assessing both strength and durability. We then explore the optimal antibiotic dosage to load into cement, aiming to achieve effective local concentrations for infection control without compromising mechanical stability. Furthermore, we explore how cement and antibiotic properties affect the overall antibiotic elution characteristics of ALC. Finally, we discuss risks of systemic toxicity, particularly acute kidney injury, when using ALC. The principal goal in this review is to provide a balanced approach based on best available evidence that optimises antibiotic elution from ALC whilst minimising potential harms associated with its use.

Next-Generation Sequencing Supports Targeted Antibiotic Treatment for Culture Negative Orthopedic Infections.

The isolation of an infective pathogen can be challenging in some patients with active, clinically apparent infectious diseases. Despite efforts in the microbiology lab to improve the sensitivity of culture in orthopedic implant-associated infections, the clinically relevant information often falls short of expectations. The management of peri-prosthetic joint infections (PJI) provides an excellent example of the use and benefits of newer diagnostic technologies to supplement the often-inadequate yield of traditional culture methods as a substantial percentage of orthopedic infections are culture-negative. Next-generation sequencing (NGS) has the potential to improve upon this yield. Bringing molecular diagnostics into practice can provide critical information about the nature of the infective organisms and allow targeted therapy in these otherwise challenging situations. This review article describes the current state of knowledge related to the use and potential of NGS to diagnose infections, particularly in the setting of PJIs.

Next-generation Sequencing Results Require Higher Inoculum for Cutibacterium acnes Detection Than Conventional Anaerobic Culture.

BACKGROUND: Cutibacterium acnes has been described as the most common causative microorganism in prosthetic shoulder infections. Conventional anaerobic culture or molecular-based technologies are usually used for this purpose, but little to no concordance between these methodologies (k = 0.333 or less) has been observed. QUESTIONS/PURPOSES: (1) Is the minimum C. acnes load for detection higher for next-generation sequencing (NGS) than for anaerobic conventional culture? (2) What duration of incubation is necessary for anaerobic culture to detect all C. acnes loads? METHODS: Five C. acnes strains were tested for this study: Four strains were causing infection and were isolated from surgical samples. Meanwhile, the other was a reference strain commonly used as a positive and quality control in microbiology and bioinformatics. To create inoculums with varying degrees of bacterial load, we began with a standard bacterial suspension at 1.5 x 10 8 colony-forming units (CFU)/mL and created six more diluted suspensions (from 1.5 x 10 6 CFU/mL to 1.5 x 10 1 CFU/mL). Briefly, to do so, we transferred 200 µL from the tube with the highest inoculum (for example, 1.5 x 10 6 CFU/mL) to the following dilution tube (1.5 x 10 5 CFU/mL; 1800 µL of diluent + 200 µL of 1.5 x 10 6 CFU/mL). We serially continued the transfers to create all diluted suspensions. Six tubes were prepared per strain. Thirty bacterial suspensions were tested per assay. Then, 100 µL of each diluted suspension was inoculated into brain heart infusion agar with horse blood and taurocholate agar plates. Two plates were used per bacterial suspension in each assay. All plates were incubated at 37°C in an anaerobic chamber and assessed for growth after 3 days of incubation and daily thereafter until positive or Day 14. The remaining volume of each bacterial suspension was sent for NGS analysis to identify bacterial DNA copies. We performed the experimental assays in duplicate. We calculated mean DNA copies and CFUs for each strain, bacterial load, and incubation timepoint assessed. We reported detection by NGS and culture as a qualitative variable based on the identification or absence of DNA copies and CFUs, respectively. In this way, we identified the minimum bacterial load detected by NGS and culture, regardless of incubation time. We performed a qualitative comparison of detection rates between methodologies. Simultaneously, we tracked C. acnes growth on agar plates and determined the minimum incubation time in days required for CFU detection in all strains and loads examined in this study. Growth detection and bacterial CFU counting were performed by three laboratory personnel, with a high intraobserver and interobserver agreement (κ > 0.80). A two-tailed p value below 0.05 was considered statistically significant. RESULTS: Conventional cultures can detect C. acnes at a load of 1.5 x 10 1 CFU/mL, whereas NGS can detect bacteria when the concentration was higher, at 1.5 x 10 2 CFU/mL. This is represented by a lower positive detection proportion (73% [22 of 30]) for NGS than for cultures (100% [30 of 30]); p = 0.004). By 7 days, anaerobic cultures were able to detect all C. acnes loads, even at the lowest concentrations. CONCLUSION: When NGS is negative and culture is positive for C. acnes , there is likely a low bacterial load. Holding cultures beyond 7 days is likely unnecessary. CLINICAL RELEVANCE: This is important for treating physicians to decide whether low bacterial loads necessitate aggressive antibiotic treatment or whether they are more likely contaminants. Cultures that are positive beyond 7 days likely represent contamination or bacterial loads even below the dilution used in this study. Physicians may benefit from studies designed to clarify the clinical importance of the low bacteria loads used in this study at which both methodologies' detection differed. Moreover, researchers might explore whether even lower C. acnes loads have a role in true periprosthetic joint infection.

Sterile Setup Table in the Operating Room Is Not So Sterile.

BACKGROUND: One of the important factors for surgical site infection prevention is the implementation of an ultraclean operating room. This study was designed to evaluate back-table sterility during total joint arthroplasty. METHODS: This prospective study includes 52 patients undergoing primary total joint arthroplasty between November 2021 and January 2022. A total of 4 swabs (2 air swabs and 2 table swabs) were obtained for each case, at the conclusion of surgery and prior to the takedown of drapes. One swab from each set was sent for culture, and the other was sent for next-generation sequencing (NGS) analysis. RESULTS: Among 104 back-table swabs, a total of 13 (12.5%) organisms were isolated. Of these, 7 organisms were isolated by culture and 6 by NGS. No microorganisms were isolated by both culture and NGS from back-table swabs. Among 104 air swabs, a total of 11 (10.6%) organisms were isolated. Of these, 6 microorganisms were isolated by culture and 5 by NGS. In 4 of the 104 swabs, both culture- and NGS-isolated organisms were from air swabs. Of the 104 (12.5%) back-table and air swabs, 13 were culture positive. While more than 1 pathogen was identified in 2 air swabs, all back-table swabs were monomicrobial by culture. Pathogens were identified from 11 of 104 (10.6%) swabs by NGS, while more than 1 pathogen was identified in 4 swabs (2 air and 2 back table). CONCLUSION: The findings of this study raise an important issue that the surgical field including the sterile table setup for instruments is not "sterile" and can harbor pathogens.

2022 American Association of Hip and Knee Surgeons Symposium: Periprosthetic Joint Infection.

Periprosthetic joint infection (PJI) is the leading cause of failure in patients undergoing total joint arthroplasty. This article is a brief summary of a symposium on PJI that was presented at the annual AAHKS meeting. It will provide an overview of current technqiues in the prevention, diagnosis, and management of PJI. It will also highlight emerging technologies in this setting.

Routine Use of Closed Suction Drains Following Revision Arthroplasty May Not be Necessary.

BACKGROUND: There are numerous studies demonstrating that closed suction drainage (CSD) usage after primary total joint arthroplasty (TJA) has little to no benefit. There are little data on the role of CSDs after revision TJA. The purpose of our study was to evaluate whether there is any clinical advantage to CSD usage after revision TJA. METHODS: This retrospective study evaluated the clinical records of 2,030 patients undergoing revision TJA between 2007 and 2021. CSD was used in 472 patients and not used in 1,558 patients. Primary outcome was blood transfusion rate and secondary outcomes included total blood loss (TBL), as determined by Gross formula, wound complications (hematoma, infection, and dehiscence), and length of hospital stay. Patients undergoing revision TJA for oncologic reasons or those with incomplete datasets were excluded. RESULTS: There were no statistically significant differences in rates of allogeneic blood transfusion, TBL, and wound complications (hematoma, infection, and dehiscence) between the two groups (P = .159, .983, .192, .334, and .548, respectively). When adjusted for demographic and surgical confounders, there was no difference in transfusion and TBL rates between groups (Odds Ratio 1.04, 95% Confidence Interval 0.78-1.38, P = .780 and estimate -105.71 mL, 95% confidence interval -333.96 to 122.55, P = .364, respectively). CSD cohort had a shorter length of stay (4.30 versus 5.82 days, P < .001). CONCLUSION: We acknowledge that there is a role for CSD usage in a selected group of patients. Nevertheless, our study revealed that routine use of CSD after revision TJA does not provide an additional clinical benefit.

Plasma D-Dimer Is a Promising Marker to Guide Timing of Reimplantation: A Prospective Cohort Study.

BACKGROUND: Two-stage exchange arthroplasty remains the preferred surgical treatment for chronic periprosthetic joint infection. Currently, there is no single reliable marker to determine the optimal timing for reimplantation. The purpose of this prospective study was to assess the diagnostic utility of plasma D-dimer and other serological markers in predicting successful control of infection following reimplantation. METHODS: This study enrolled 136 patients undergoing reimplantation arthroplasty between November 2016 and December 2020. Strict inclusion criteria were applied including the need for a two-week "antibiotic holiday" prior to reimplantation. A total of 114 patients were included in the final analysis. Plasma D-dimer, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and fibrinogen were measured preoperatively. Treatment success was defined using the Musculoskeletal Infection Society Outcome-Reporting Tool. Receiver operating characteristic curves were used to assess the prognostic accuracy of each biomarker in predicting failure following reimplantation at a minimum 1-year follow-up. RESULTS: Treatment failure occurred in 33 patients (28.9%) at a mean follow-up of 3.2 years (range, 1.0 to 5.7). Median plasma D-dimer was significantly higher in the treatment failure group (1,604 versus 631 ng/mL, P < .001), whereas median CRP, ESR, and fibrinogen were not significantly different between the success and failure groups. Plasma D-dimer demonstrated the best diagnostic utility (area under the curve [AUC] 0.724, sensitivity 51.5%, specificity 92.6%), outperforming ESR (AUC 0.565, sensitivity 93.3%, specificity 22.5%), CRP (AUC 0.541, sensitivity 87.5%, specificity 26.3%), and fibrinogen (AUC 0.485, sensitivity 30.4%, specificity 80.0%). Plasma D-dimer level of ≥1,604 ng/mL was identified as the optimal cutoff that predicted failure following reimplantation. CONCLUSION: Plasma D-dimer was superior to serum ESR, CRP, and fibrinogen in predicting failure after the second stage of a two-stage exchange arthroplasty for periprosthetic joint infection. Based on the findings of this prospective study, plasma D-dimer may be a promising marker in assessing the control of infection in patients undergoing reimplantation surgery. LEVEL OF EVIDENCE: Level II.

Mark Coventry Award: Human Knee Has a Distinct Microbiome: Implications for Periprosthetic Joint Infection.

BACKGROUND: Pathogens causing prosthetic joint infection (PJI) are thought to gain access to the knee during surgery or from a remote site in the body. Recent studies have shown that there is a distinct microbiome in various sites of the body. This prospective study, and first of its kind, was set up to investigate the presence of possible microbiome in human knee and compare the profile in different knee conditions. METHODS: We obtained synovial fluid from 65 knees (55 patients) with various conditions that included normal knee, osteoarthritis (OA), aseptic revision, and those undergoing revision for PJI. The contralateral knee of patients who had a PJI were also aspirated for comparison. A minimum of 3 milliliters of synovial fluid was collected per joint. All samples were aliquoted for culture and next-generation sequencing analysis. RESULTS: The highest number of species was found in native osteoarthritic knees (P ≤ .035). Cutibacterium, Staphylococcus, and Paracoccus species were dominant in native nonosteoarthritic knees, and meanwhile a markedly high abundance of Proteobacteria was observed in the osteoarthritic joints. Moreover, the contralateral and aseptic revision knees showed a similar trend in bacterial composition (P = .75). The sequencing analysis of patients who had PJI diagnosis, confirmed the culture results. CONCLUSION: Distinct knee microbiome profiles can be detected in patients who have OA and other knee conditions. The distinct microbiome in the knee joint and the close host-microbe relationships within the knee joint may play a decisive role in the development of OA and PJI.

Patients Who Have Had Three or More Levels Fused During Lumbar Spinal Fusion Have Worse Functional Outcomes After Total Hip Arthroplasty.

BACKGROUND: Lumbar spinal fusion (LSF) and total hip arthroplasty (THA) are commonly performed in patients who have concomitant spine and hip pathology. While patients who have three or more levels fused during LSF have increased postoperative opioid consumption after undergoing THA, it is unknown whether the number of levels fused during LSF affects THA functional outcomes. METHODS: A retrospective study was conducted at a tertiary academic center for patients who underwent LSF first and then had a primary THA performed with a minimum of one-year follow-up for the Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS-JR). Operative notes were reviewed to determine the number of levels fused during LSF. There were 105 patients who underwent one-level LSF, 55 patients underwent two-level LSF, and 48 patients underwent three-or-more-level LSF. No significant differences existed in age, race, body mass index, and comorbidities between the cohorts. RESULTS: While preoperative HOOS-JR was similar among the three cohorts, patients who had three-or-more-level LSF had significantly lower HOOS-JR scores than patients who had two-level or one-level LSF (71.4 versus 82.4 versus 78.2; P = .010) and a lower delta HOOS-JR (27.2 versus 39.4 versus 35.9; P = .014). Patients who had three-or-more-level LSF had a significantly lower rate of achieving minimal clinically important difference (61.7% versus 87.2% versus 78.7%; P = .011) and the patient acceptable symptom state (37.5% versus 69.1% versus 59.0%; P = .004) for the HOOS-JR, compared to patients who had two-level or one-level LSF, respectively. CONCLUSIONS: Surgeons should counsel patients who have had three-or-more-level LSF that they may have a lower rate of hip function improvement and symptom acceptability after THA, compared to patients who have had a less number of levels fused during LSF.

For Patients With Acute PJI Treated With Debridement, Antibiotics, and Implant Retention, What Factors Are Associated With Systemic Sepsis and Recurrent or Persistent Infection in Septic Patients?

BACKGROUND: Periprosthetic joint infection (PJI) can lead to a severe systemic inflammatory response and may result in systemic sepsis. However, little is known about how often systemic sepsis may occur in patients with PJI, and whether sepsis is associated with a greater likelihood of persistent or recurrent PJI. QUESTIONS/PURPOSES: (1) Among patients who present with acute or acute hematogenous PJI and who were treated with debridement, antibiotics, and implant retention (DAIR), what proportion have sepsis and what factors are associated with a presentation with sepsis? (2) For patients presenting with sepsis, what factors are associated with persistent or recurrent PJI? METHODS: In all, 320 patients who underwent DAIR for the treatment of acute postoperative or acute hematogenous PJI between January 2000 and December 2019 were included in this study. Exclusion criteria were patients with other known sources of infection, such as pneumonia or urinary tract infections, which could contribute to systemic sepsis (6% [18 of 320]), patients with chronic PJI, and those with less than 6 months of follow-up (21% [66 of 320]). Our final cohort consisted of 236 patients presenting with an acute postoperative or acute hematogenous PJI who underwent an irrigation and debridement procedure. Sepsis was defined by the criteria for systemic inflammatory response syndrome (SIRS) or bacteria-positive blood culture results. Inclusion of patients with positive blood culture by organisms that caused their joint infection was important as all patients presented with fulminant acute infection of a prosthetic joint. Data, including vital signs, surgical variables, and treatment outcomes, were collected retrospectively through a chart review of an electronic medical record system. The statistical analysis comparing patients with sepsis versus patients without sepsis consisted of logistic regression to identify factors associated with sepsis. After confirming its ability to identify patients with a higher association with the development of sepsis through area under the curve models, a nomogram was generated to standardize our results from the regression, which was supported by the area under the curve model, to help readers better identify patients who are more likely to develop sepsis. RESULTS: A total of 44% (103 of 236) of patients had infections that met the criteria for sepsis. After controlling for confounding variables, including congestive heart failure, anemia, serum C-reactive protein (CRP), and the male sex, it was revealed that serum CRP (odds ratio 1.07 [95% confidence interval 1.04 to 1.11]; p < 0.001) and male sex (OR 1.96 [95% CI 1.03 to 3.81]; p = 0.04) were associated with the development of systemic sepsis. For patients presenting with sepsis, persistent or recurrent PJI were associated with an increased CRP level (OR 1.06 [95% CI 1.02 to 1.11]; p = 0.01) and number of prior surgical procedures on the joint (OR 2.30 [95% CI 1.21 to 4.89]; p = 0.02). CONCLUSION: Overall, our findings support that patients with systematic sepsis may benefit from two-stage revision rather than DAIR to decrease the bioburden more effectively, especially in those with methicillin-resistant Staphylococcus aureus and polymicrobial infections. High serum CRP levels and a history of prior surgical procedures on the involved joint should trigger prompt, aggressive surgical treatment if the patient's overall clinical status can tolerate such an intervention. LEVEL OF EVIDENCE: Level III, therapeutic study.