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.

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

INTRODUCTION: 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 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 = 0.037). 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. CONCLUSION: 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.

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.

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.

Dogs can detect an odor profile associated with Staphylococcus aureus biofilms in cultures and biological samples.

Introduction: The study investigated the utilization of odor detection dogs to identify the odor profile of Staphylococcus aureus (S. aureus) biofilms in pure in vitro samples and in in vivo biosamples from animals and humans with S. aureus periprosthetic joint infection (PJI). Biofilms form when bacterial communities aggregate on orthopedic implants leading to recalcitrant infections that are difficult to treat. Identifying PJI biofilm infections is challenging, and traditional microbiological cultures may yield negative results even in the presence of clinical signs. Methods: Dogs were trained on pure in vitro S. aureus biofilms and tested on lacrimal fluid samples from an in vivo animal model (rabbits) and human patients with confirmed S. aureus PJI. Results: The results demonstrated that dogs achieved a high degree of sensitivity and specificity in detecting the odor profile associated with S. aureus biofilms in rabbit samples. Preliminary results suggest that dogs can recognize S. aureus volatile organic compounds (VOCs) in human lacrimal fluid samples. Discussion: Training odor detection dogs on in vitro S. aureus, may provide an alternative to obtaining clinical samples for training and mitigates biosecurity hazards. The findings hold promise for culture-independent diagnostics, enabling early disease detection, and improved antimicrobial stewardship. In conclusion, this research demonstrates that dogs trained on in vitro S. aureus samples can identify the consistent VOC profile of PJI S. aureus biofilm infections. The study opens avenues for further investigations into a retained VOC profile of S. aureus biofilm infection. These advancements could revolutionize infectious disease diagnosis and treatment, leading to better patient outcomes and addressing the global challenge of antimicrobial resistance.

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.

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.

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.

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.

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.

Venous thromboembolism in orthopedic surgery: Global guidelines.

Venous thromboembolism (VTE) is a severe complication that can occur after major orthopedic procedures. As VTE-related morbidity and mortality are a significant concern for both medical professionals and patients, and preventative measures are typically employed. Multiple organizations, including the American College of Chest Physicians (ACCP) and the American Academy of Orthopedic Surgeons (AAOS), have developed guidelines for VTE prophylaxis specifically in patients undergoing joint replacement procedures. However, recently, the International Consensus Meeting (ICM) was convened, which brought together over 600 experts from 68 countries and 135 international societies. These experts, spanning a range of medical disciplines including orthopedic surgery, anesthesia, cardiology, hematology, vascular, and internal medicine, conducted a comprehensive review of the literature using a strict Delphi process to generate practical recommendations for VTE prophylaxis across all types of orthopedic procedures. This review article summarizes some of the recommendations of the ICM.

Enough is enough: salvage procedures in severe periprosthetic joint infection.

BACKGROUND: In severe cases of periprosthetic joint infection involving negative host-dependent factors, individual-based decisions between a curative therapy vs. salvage procedure are necessary. We aimed to review salvage procedures in severe periprosthetic joint infection cases, where a gold standard of a curative two-stage exchange can no longer be achieved. The options of knee arthrodesis, amputation, persistent fistula (stable drainage), or a debridement, antibiotics, and implant retention procedure in late-onset cases are discussed, including lifelong antibiotic suppression alone. METHODS: We focused on known salvage procedures for severe periprosthetic joint infection of the hip and knee, such as amputation, arthrodesis, antibiotic suppression, persistent fistula, and debridement, antibiotics, and implant retention in late-stage infections, and the role of local antibiotics. The current literature regarding indications and outcomes was reviewed. RESULTS: Whereas a successful single-stage above-knee amputation can be a curative effort in younger patients, this is associated with limited outcome in older patients, as the proportion who receive an exoprosthesis leading to independent mobility is low. Therefore, arthrodesis using an intramedullary modular nail is an option for limb salvage, pain reduction, and preservation of quality of life and everyday life mobility, when revision total knee arthroplasty is not an option. Carrying out a persistent fistula using a stable drainage system, as well as a lifelong antibiotic suppression therapy, can be an option, in cases where no other surgery is possible. Active clinical surveillance should then be carried out. A debridement, antibiotics, and implant retention procedure in combination with local degradable antibiotics can be used and is an encouraging new option, but should not been carried out twice. CONCLUSION: Whereas the gold standard in periprosthetic joint infection treatment of late infections remains the exchange of the prosthesis, salvage procedures should be considered in the cases of reduced life expectancy, several recurrences of the infection, patients having preference and negative host factors. In these cases, the appropriate salvage procedure can temporarily lead to remission of the infection and the possibility to maintain mobility.

Current relevance of biomarkers in diagnosis of periprosthetic joint infection: an update.

With a significant rise in the number of arthroplasty procedures performed worldwide, the increasing revision burden posed by periprosthetic joint infection (PJI) is a matter of growing concern. In spite of various attempts to diagnose PJI, there are no defined tests that can be called a gold standard. Given the importance of early diagnosis in PJI, newer tests and biomarkers have been introduced to improve cumulative diagnostic accuracy. Novel biomarkers like calprotectin, lipocalcin, monocyte-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and platelet-to-mean platelet volume ratio have demonstrated a potential as diagnostic biomarkers for PJI. This article discusses the relevance of available and newly described diagnostic biomarkers to provide a perspective on the practical applicability in current medical practice, as well as highlights some recent advances in biomarkers for the diagnosis of PJI.

Allograft reconstruction of acetabular labrum has comparable outcomes to labral refixation.

The acetabular labrum plays an important role in hip stability, intra-articular fluid pressurization and force distribution. For irreparable labral pathology, labral reconstruction is an increasingly adopted technique shown to decrease hip pain and improve function. We evaluated survivorship and clinical outcomes of allograft labral reconstruction using the mini-open anterior surgical approach. Twelve patients who underwent labral reconstruction using a semitendinosus tendon allograft (reconstruction group) were matched 1:3 based on age, gender, body mass index, year of surgery, preoperative Tönnis grade, previous hip surgery, residual hip pathology and extent of acetabular chondral lesion to a control group of 36 patients who underwent direct labral repair with anchors (refixation group). At a minimum follow-up of 2 years, patient-reported outcomes, radiological findings and failure rates were compared. The average age was 31.3 years (±13.6) for reconstruction and 34.7 (±10.2) for refixation. Both groups had similar preoperative symptomatic periods (P = 0.3), prevalence of residual hip pathology (P = 1.0) and prevalence of prior hip surgeries (P = 1.0). both groups had a significant improvement of modified Harris Hip scores and 36-Item Short-Form Health Survey physical scores. There was no statistically significant difference in conversion rates to total hip arthroplasty (25% versus 8.3%, P = 0.2); however, time to conversion was significantly longer in the reconstruction group (3.58 years ±1.04) compared to the refixation group (1.20 years± 0.93; P = 0.04). In conclusion, at a minimum of 2 years of follow-up, mini-open labrum reconstruction for severe insufficiency of acetabular labrum demonstrated comparable improvements in functional outcomes and significantly longer survivorship compared to labral refixation.

Diagnosis of Periprosthetic Joint Infection: The Utility of Biomarkers in 2023.

Periprosthetic joint infection (PJI) is a rare yet devastating complication following total joint arthroplasty (TJA). Early and accurate diagnosis of PJI is paramount in order to maximize the chances of successful treatment. However, we are yet to identify a single "gold standard" test for the diagnosis of PJI. As a result, the diagnosis of PJI is often challenging. Currently, the 2018 ICM definition of PJI is the only validated diagnostic criteria available. This article will review the importance of serum and synovial biomarkers in the diagnosis of PJI. In addition, it will provide a brief overview of the emerging modalities for the identification of infections in this setting.

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.