Background Patients who have a history of treated prosthetic joint infection (PJI) in total joint arthroplasty (TJA) may represent a high-risk population for repeat PJI when undergoing another primary TJA. The purpose of this study was to determine the incidence of PJI following primary total hip or knee arthroplasty in patients who had a history of surgically treated PJI in another joint and to identify risk factors associated with subsequent infection. Methods We performed a retrospective secondary analysis of patients who underwent primary total hip or knee arthroplasty after prior treatment of PJI in another hip or knee joint with debridement, antibiotics, and implant retention (DAIR) or one- or two-stage revision. Patients were identified from an institutional database between 2010 and 2023. The primary outcome was subsequent PJI, evaluated by treatment strategy and patient factors. Demographics, comorbidities, surgical variables, microbiology, and timing between procedures were collected. Results The incidence of PJI after one year in primary TJA in patients who had a history of treated PJI was 1.5%. We did not observe a higher risk of PJI in comparison with the control cohort (P = 0.25). Those treated with one- or two-stage exchange were at higher risk (2.2%) versus prior treatment with DAIR (zero). Patients who had a history of PJI had a higher comorbidity burden than controls, with a significantly greater proportion of McPherson Type B and C hosts (P < 0.0001). Polymicrobial infections were most common. Conclusions Patients who had a history of PJI undergoing subsequent primary TJA in another joint have a higher comorbidity burden than control TJA patients. Nevertheless, when appropriately optimized, they can safely undergo TJA with a low infection risk comparable to controls at one year. Medical optimization should be pursued to maximize outcomes in these challenging patients.

BACKGROUND:Periprosthetic joint infection (PJI) remains a major source of morbidity, mortality, and economic burden, both in the United States and internationally. Understanding regional microbiology profiles in PJI is essential to assist with empiric antibiotic selection. The purpose of this study was to survey an international database to identify and compare the microbiological profile of hip and knee PJI across international sites. METHODS:A multicenter, international database that included all patients admitted to participating hospitals who had a confirmed diagnosis of PJI was utilized. In the present study, data from four institutions in the following cities were retrospectively reviewed: Melbourne (Australia, n = 167), Groningen (the Netherlands, n = 117), Weston (Florida, United States of America, n = 201), and Charlotte (North Carolina, United States of America, n = 180). The most common organisms identified in hip and knee PJI were compared between institutions. Rates of polymicrobial, fungal, and culture-negative PJI specifically were also evaluated. A total of 665 patients who had PJI were included (311 hip and 354 knee). RESULTS:Coagulase-negative staphylococci were the most frequently isolated pathogens across all centers (26.5 to 38%), followed by Staphylococcus aureus (13 to 27%). Rates of polymicrobial PJI were high and varied widely between institutions (14 to 51%), whereas rates of fungal PJI were low and consistent between regions (1 to 3%). The prevalence of culture-negative PJI varied between 8% (Australia) and 22% (Florida). CONCLUSIONS:While subtle regional differences in the microbiology of PJI exist, Staphylococcus species remained the dominant pathogen, accounting for nearly half of the PJIs at each center. Differences in polymicrobial and culture-negative infections emphasize the impact of institutional and geographic factors, supporting the development of region-specific empiric and prophylactic antibiotic protocols.

Joint arthroplasty, replacement of damaged articular surfaces with a prosthetic component, is an increasingly common orthopaedic procedure. Despite the overall success of arthroplasty, complications such as periprosthetic joint infection remain a persistent problem with severe consequences. With increasing clinical demands, the need for a reliable, reproducible model for testing therapeutic strategies for arthroplasty complications is fundamental. In this study, a novel small animal model was designed and evaluated for downstream investigations. Two different implant designs (tibial vs. femoral) and surgical approaches were compared. The femoral implant resulted in fewer complications such as knee joint destabilization, severe swelling, and erosion of articular cartilage and subchondral bone. Rabbit care methodology was also optimized during model development, and both the process and results are presented to promote ethical and reproducible preclinical model research. The custom porous coated unicondylar femoral implant with a polished condylar surface demonstrated far fewer complications and adverse events than the tibial implant, as well as robust osseointegration. This will serve as a model for future investigations in preventing and treating joint arthroplasty complications. Joint arthroplasty, replacement of damaged articular surfaces with a prosthetic component, is an increasingly common orthopaedic procedure. Despite the overall success of arthroplasty, complications such as periprosthetic joint infection remain a persistent problem with severe consequences. With increasing clinical demands, the need for a reliable, reproducible model for testing therapeutic strategies for arthroplasty complications is fundamental. In this study, a novel small animal model was designed and evaluated for downstream investigations. Two different implant designs (tibial vs. femoral) and surgical approaches were compared. The femoral implant resulted in fewer complications such as knee joint destabilization, severe swelling, and erosion of articular cartilage and subchondral bone. Rabbit care methodology was also optimized during model development, and both the process and results are presented to promote ethical and reproducible preclinical model research. The custom porous coated unicondylar femoral implant with a polished condylar surface demonstrated far fewer complications and adverse events than the tibial implant, as well as robust osseointegration. This will serve as a model for future investigations in preventing and treating joint arthroplasty complications.

Background: 2-stage revision arthroplasty remains the current gold standard for treatment of chronic periprosthetic joint infection (PJI) of the hip and knee in the United States. Rates of infection eradication have been shown to vary from 60% to 91%. The purpose of this study was to determine the true fate the of 2-stage exchange protocol for PJI using an updated classification system for PJI treatment outcomes as well as the effect of systemic host and local extremity grades on outcomes.Methods: A retrospective review of a PJI registry was performed from a single institution from January 2010 through December 2021. All patients having undergone a planned 2-stage exchange after primary or revision total knee arthroplasty (TKA) and total hip arthroplasty (THA) for chronic PJI defined by Musculoskeletal Infection Society criteria were included. Perioperative variables and tiered outcome at final follow up were collected.Results: In total, 589 cases (561 patients) met final inclusion criteria and were included in the analysis. 394 cases (66.9%) retained their implants at median follow-up of 3.7 years (IQR 1.8, 7.7). 311 cases (52.8%) underwent successful two-stage revision with prosthesis retention without ongoing use of suppressive antibiotics, while another 83 cases (14.1%) retained their prosthesis with use of suppressive antibiotics. 152 cases (25.8%) underwent subsequent septic or aseptic revision, amputation, arthrodesis, spacer retention while 40 (6.8%) died during the study period.Conclusions: At 3.7 years after surgery, 66.9% of 2-stage exchanges for PJI resulted in retained prosthesis with or without use of suppressive antibiotics. The remaining 33.1% of this population underwent additional surgery (25.8%), or were deceased (6.8%).

BACKGROUND:A 2-stage approach is most commonly used to treat periprosthetic joint infection (PJI). Some successful studies of the 1-stage approach were underpowered, lacked a 2-stage comparative group, and excluded patients with draining sinuses, comorbidities, and/or antibiotic-resistant organisms. Given the morbidity and expense associated with 2-stage treatment, we conducted a prospective, multicenter, randomized trial to compare the results of 1- and 2-stage PJI treatment, specifically including patients with draining sinuses, comorbidities, and resistant organisms. METHODS:Patients presenting for surgical treatment of a chronic PJI with a known organism following primary total hip or knee arthroplasty were included (with infection defined by Musculoskeletal Infection Society [MSIS] criteria). Patients with prior revision, culture-negative infection, or fungal infection, or who were immunosuppressed or had soft-tissue involvement precluding wound closure, were excluded. Patients were classified according to the McPherson host staging system. Clinical success was defined as (1) no clinical failure or reinfection with the same or new organism; (2) no reoperation for PJI; and (3) no PJI-related death. A double-instrument setup was used for all patients, as were similar irrigation and antibiotic protocols. A total of 323 patients (166 one-stage; 157 two-stage) were randomized. Groups were similar with respect to demographics and host classification. After excluding patients who died or were lost to follow-up, 258 of the 323 patients had 2-year follow-up (135 one-stage and 123 two-stage). The rate of patient loss to follow-up was similar between the treatment groups. RESULTS:Sixteen patients in the 1-stage group and 9 patients in the 2-stage group died prior to 2-year follow-up. Overall, the 2-year success rate of 1-stage treatment was 97% (131 of 135), while the success of 2-stage treatment was 91% (112 of 123) (p = 0.04). Compared with the 2-stage group, the 1-stage group had 3-times the odds of overall success in a regression analysis (unadjusted odds ratio = 3.22 [95% confidence interval = 1.0 to 10.38]). After adjusting for specific variables (McPherson host grade, resistant organism, and draining sinuses), 1-stage treatment also had 3-times the odds of success. CONCLUSIONS:The results of this prospective randomized trial indicated that 1-stage treatment (97% success) was statistically noninferior to 2-stage treatment (91% success) when treating chronic PJI following primary total hip or knee arthroplasty, provided the protocols described here are explicitly followed. Extrapolation to other patient cohorts and clinical situations should be avoided. LEVEL OF EVIDENCE:Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Background: A 2-stage approach is most commonly used to treat periprosthetic joint infection (PJI). Some successful studies of the 1-stage approach were underpowered, lacked a 2-stage comparative group, and excluded patients with draining sinuses, comorbidities, and/or antibiotic-resistant organisms. Given the morbidity and expense associated with 2-stage treatment, we conducted a prospective, multicenter, randomized trial to compare the results of 1- and 2-stage PJI treatment, specifically including patients with draining sinuses, comorbidities, and resistant organisms. Methods: Patients presenting for surgical treatment of a chronic PJI with a known organism following primary total hip or knee arthroplasty were included (with infection defined by Musculoskeletal Infection Society [MSIS] criteria). Patients with prior revision, culture-negative infection, or fungal infection, or who were immunosuppressed or had soft-tissue involvement precluding wound closure, were excluded. Patients were classified according to the McPherson host staging system. Clinical success was defined as (1) no clinical failure or reinfection with the same or new organism; (2) no reoperation for PJI; and (3) no PJI-related death. A double-instrument setup was used for all patients, as were similar irrigation and antibiotic protocols. A total of 323 patients (166 one-stage; 157 two-stage) were randomized. Groups were similar with respect to demographics and host classification. After excluding patients who died or were lost to follow-up, 258 of the 323 patients had 2-year follow-up (135 one-stage and 123 two-stage). The rate of patient loss to follow-up was similar between the treatment groups. Results: Sixteen patients in the 1-stage group and 9 patients in the 2-stage group died prior to 2-year follow-up. Overall, the 2-year success rate of 1-stage treatment was 97% (131 of 135), while the success of 2-stage treatment was 91% (112 of 123) (p = 0.04). Compared with the 2-stage group, the 1-stage group had 3-times the odds of overall success in a regression analysis (unadjusted odds ratio = 3.22 [95% confidence interval = 1.0 to 10.38]). After adjusting for specific variables (McPherson host grade, resistant organism, and draining sinuses), 1-stage treatment also had 3-times the odds of success. Conclusions: The results of this prospective randomized trial indicated that 1-stage treatment (97% success) was statistically noninferior to 2-stage treatment (91% success) when treating chronic PJI following primary total hip or knee arthroplasty, provided the protocols described here are explicitly followed. Extrapolation to other patient cohorts and clinical situations should be avoided. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

BACKGROUND:Periprosthetic joint infection (PJI) represents a devastating complication following total joint arthroplasty. Understanding trends in causative organisms and antibiotic resistance patterns is necessary for optimizing treatment strategies. We investigated (1) whether there has been a change in prevalence of drug-resistant organisms in surgically treated PJI over the past decade and (2) if there are risk factors associated with drug-resistant PJI. METHODS:A retrospective review of our institutional database was performed for surgically treated PJI between January 1, 2010, and December 31, 2021. A total of 915 patients met Musculoskeletal Infection Society criteria for PJI. The prevalence of patients who had drug-resistant organisms was recorded and compared over the study duration. Of 915 procedures, 25.1% (N = 230) were caused by resistant organisms. The most common resistant organisms were methicillin-resistant Staphylococcus aureus (63.0%), methicillin-resistant Staphylococcus epidermidis (24.3%), and resistant coagulase-negative Staphylococci (16.1%). RESULTS:Total PJI cases increased from 53 in 2010 to 109 in 2021, while resistant organism cases increased from 22 to 30. The percentage of resistant PJI decreased from 41.5% (22 of 53) in 2010 to 25.1% (30 of 109) in 2021, with no significant trend (P = 0.85). Patients who had higher comorbidity burden had significantly higher rates of resistant infections (P = 0.04), as did patients who had local extremity compromise (P = 0.01). The methicillin-resistant Staphylococcus epidermidis and resistant coagulase-negative Staphylococci were more common in knee infections. CONCLUSIONS:While PJI referrals to our center increased over time, the percentage of surgically treated PJIs caused by resistant organisms decreased, although not significantly. Patients who had a higher comorbidity burden and local extremity compromise were predictive of resistant infections. Understanding microbiological profiles remains critical for optimizing treatment strategies in referral centers.

Background: Culture-negative periprosthetic joint infections (CN-PJIs) remain a major problem in the field of orthopedic infections. The clinical features of CN-PJI and its risk factors remain poorly defined. The purpose of this study was to elucidate the characteristics of CN-PJI. Methods: This was a retrospective multi-center cohort study as part of the Orthopaedic Device Infection Network (ODIN). Using real-world data from five institutions across Australia, the Netherlands and the USA, 563 cases of PJI (470 culture positive, 93 culture negative) were queried between 1995 and 2021. Patients with CN-PJI had negative cultures on pre-operative aspiration, blood or intra-operative cultures. Demographics, history of surgery on the infected joint, presenting symptoms, operative details, laboratory values and intra-operative findings were recorded. Multivariable regression was used to determine the association between these variables and culture negativity. Results: The prevalence of CN-PJI was 16.5 %. Bivariate analysis revealed that patients with CN-PJI were more likely to be female, have a revision arthroplasty or prior PJI, have a longer duration of symptoms and were less likely to present with fever, wound dehiscence or wound necrosis; they also had lower hemoglobin and serum CRP ( p < 0.05 for all). Using multivariable regression, the only factor significantly associated with CN-PJI was a duration of symptoms of > 12 weeks (OR 2.24, 95 % CI 1.008-4.964, p = 0.048 ). Conclusions: Patients with prolonged symptoms were twice as likely to have negative cultures, supporting the traditional belief that CN-PJI presents more insidiously. These clinical data should be used to guide the selection of advanced investigations.

BACKGROUND:Periprosthetic joint infection (PJI) is a challenging complication following total joint arthroplasty. A two-stage exchange has been the gold standard in the treatment of chronic PJI. However, when this fails, further treatment options become limited. In patients who fail two-stage exchange, the reinfecting organism is different from the original in 50 to 80% of the occurrences. This study aimed to understand reinfection patterns in an attempt to better predict reinfecting organisms to improve the management of PJI. METHODS:A retrospective query of our institution's PJI registry identified 185 patients (188 procedures, 110 knees, and 78 hips) who underwent a first-time two-stage exchange for culture-positive chronic PJI of total knee and hip arthroplasties from January 2010 to December 2020. Patients who had polymicrobial infections, culture-negative results, or fungal infections were excluded. The primary outcome variable was reoperation for reinfection and comparing the index organism to the reinfecting organisms. RESULTS:Of the 188 procedures, 31 (16.5%) failed due to reinfection. Among reinfections, 30 (96.8%) were gram-positive, with Staphylococcus aureus species accounting for 22 (71.0%) of the cases. The most common organisms cultured were for methicillin-sensitive S. Aureus, methicillin-resistant S. Aureus, coagulase-negative staphylococcus, and streptococcus. Of reinfections, 19 (61.3%) had a different organism, eight (25.8%) had the same organism, and four (12.9%) were culture-negative. Patients experiencing reinfection were significantly younger (P = 0.012), with no other patterns or predictors identified. CONCLUSIONS:The majority of reinfections following a two-stage exchange for PJI occur with a different organism than the index infection. We did not find a reliable method to predict the reinfecting organisms based on the initial infecting organism alone. However, the same four gram-positive organisms were the most frequently encountered in both the primary infection and the reinfection. Further research is required to understand factors contributing to reinfection and help guide prevention strategies.

BACKGROUND:Debridement, antibiotics, and implant retention (DAIR) requires careful patient selection. The CRIME80 (COPD, C-reactive protein, Rheumatoid arthritis, Index surgery, Male, Exchange of mobile components, age greater than 80 years) score is a tool designed to predict treatment failure in patients who have late-acute PJI treated with DAIR. We aimed to assess the predictive performance of the CRIME80 score in patients who have early and late acute PJI. METHODS:We conducted an international multicenter validation study using retrospectively collected data from patients who had acute infections of the hip or knee treated with DAIR. Failure was defined as: (i) removal of the prosthesis; (ii) the need for suppressive antibiotics one or more years after surgery for PJI; (iii) relapse of infection as determined by the treating clinician; (iv) repeated DAIR more than seven days after the initial procedure; or (v) death. Nonparametric estimation of the area under the receiver operating curve (AUC) was used to establish the discriminative performance of the CRIME80 score. The cohort included 281 knee and 99 hip infections treated with DAIR. RESULTS:Although the CRIME80 score showed a linear trend with failure, the score only had modest discriminative performance (AUC in hip PJI: 0.63, 95% confidence interval (CI) 0.51 to 0.74; AUC in knee PJI: 0.57, 95% CI 0.51 to 0.64). There was no significant difference in performance in early acute (AUC: 0.62, 95% CI 0.55 to 0.69) and late acute (AUC: 0.55, 95% CI 0.45 to 0.65) infections. This finding was consistent across several sensitivity analyses. CONCLUSIONS:Our study found that the CRIME80 tool had limited predictive performance. This finding was consistent across patients who had PJI of the hip or knee and early or late acute infection. Given these findings, the benefit of implementing the CRIME80 score in clinical practice remains uncertain.

BACKGROUND:Late acute hematogenous periprosthetic joint infections (LAHPJIs) pose a unique challenge to the arthroplasty surgeon. While debridement, antibiotics, and implant retention (DAIR) is a common method for treatment, success rates vary widely. Our study aimed to provide clarity on the efficacy of DAIR in treating LAHPJIs, as well as to identify factors associated with treatment success, which may guide decision-making for optimizing patient outcomes. METHODS:A retrospective review of all LAHPJI cases treated with DAIR from 2010 to 2020 at a single institution was performed. A LAHPJI was defined as symptoms < four weeks in a joint that is > three months from surgery. A PJI was defined by the Musculoskeletal Infection Society criteria. Patients were classified based on McPherson classification, which includes host type (A, B, or C) and extremity grade (1, 2, or 3). Failure was defined as recurrent infection. In total, 152 LAHPJIs (110 knees, 42 hips) were included with a median follow-up of 6.4 years. RESULTS:Kaplan-Meier analysis demonstrated 75% infection-free survival at five years, with 70.7% of failures occurring within the first year after DAIR. McPherson systemic host grade significantly predicted the success of DAIR, with failure rates of 8.7, 24.4, and 40% in type A, B, and C hosts, respectively (P = 0.02). Multivariable regression revealed that type C hosts were 5.3 times more likely to fail treatment than type A (95% confidence interval 1.06 to 26.75, P = 0.04). Polymicrobial infections were most common (30.3%), followed by methicillin-sensitive Staphylococcus aureus (16.4%). CONCLUSIONS:A DAIR is a viable treatment option for LAHPJI, especially in type A hosts. Careful history should confirm symptoms for less than four weeks. Patients who have a high comorbidity burden and elevated preoperative inflammatory labs should be monitored closely for treatment failure.

BACKGROUND:While numerous risk factors have been associated with failure following a two-stage exchange for periprosthetic joint infection (PJI), little prior research has evaluated specifically when failure occurs postoperatively. The purpose of this study was to investigate the timing of failure following a two-stage exchange for chronic PJI and to determine whether any patient- or organism-specific risk factors are associated with early failure. METHODS:From our institutional registry, we identified 589 two-stage exchanges performed for PJI of the hip or knee from 2010 to 2021. After excluding patients for lack of failure (n = 357) and inadequate chart information (n = 142), we were left with 90 (15% of 589) total joint arthroplasties (56 knees and 34 hips) in 90 patients that failed following a two-stage exchange. These patients were divided into two groups by the timing of failure: early (within 5 years postoperatively) and late (> 5 years postoperatively). Potential patient- and organism-specific risk factors for failure were compared between groups. RESULTS:The median time to failure was 579 days (interquartile range, 204 to 1,246). The cumulative percentage of patients who failed within 1, 5, and 10 years following reimplantation was 40, 84, and 98%, respectively. Systemic inflammatory disease was associated with early failure (n = 21 early failures versus n = 0 late failures; P = 0.03), with 100% of patients who had systemic inflammatory disease failing early. A resistant organism identified intraoperatively trended toward being significantly associated with early failure (n = 16 early failures versus n = 0 late failures; P = 0.10). CONCLUSIONS:Most failures following a two-stage exchange (84%) occurred early, within 5 years following reimplantation. Patients with systemic inflammatory disease and/or a resistant organism identified intraoperatively were most at risk for early failure. These data may guide surgeons regarding follow-up monitoring and the duration of suppressive antibiotics. LEVEL OF EVIDENCE:Level IV, retrospective review.

We report a case of a 74-year-old female with a history of a prosthetic joint infection that was successfully treated with a single-stage exchange arthroplasty, off antibiotics, and without symptoms for 20 months. She presented 1 week after a cat scratch with acute knee pain, and aspiration grew Pasteurella multocida. She was successfully treated with surgical debridement and a prolonged course of antibiotics. Debate remains in the literature regarding whether recurrent infections represent a previously undetected organism or a new infection. Our report provides convincing evidence that, at least in some circumstances, the infection is new. Furthermore, this is the first case described of P. multocida resulting in a recurrent prosthetic joint infection after a previously successful exchange arthroplasty due to a different causative organism.

BACKGROUND:In recent years, there has been an increased utilization of dual-mobility (DM) implants in primary total hip arthroplasty (THA) to mitigate the risk of postoperative hip instability. This study aimed to present mid-term outcomes of DM bearings in primary THA using data from the American Joint Replacement Registry. METHODS:Screening was conducted on patients aged ≥ 65 years who underwent primary THA between 2012 and 2018. Patients were categorized into three groups: (1) DM articulation, (2) ≤ 32-mm femoral head, and (3) ≥ 36-mm femoral head. Multivariable statistical modeling was employed to analyze patient and hospital characteristics, minimizing potential confounding variables and identifying independent associations with revision. Cox proportional hazards regression analyses were used to assess all-cause revision and revision specifically for instability. A total of 207,526 primary THAs were identified. Among them, 13,896 (6.7%) utilized DM articulation, 60,358 (29.1%) had a femoral head size of ≤ 32 mm, and 133,272 (64.2%) had a femoral head size of ≥ 36 mm. RESULTS:At the 8-year follow-up, the all-cause revision rate was higher in the DM group (3.5%, 95% confidence interval [CI] 3.1 to 4.1) compared to the ≤ 32-mm (2.6%, 95% CI 2.5 to 2.8) and ≥ 36-mm (2.7%, 95% CI 2.5 to 2.9) groups. However, the revision rate for instability was comparable among the DM (0.4%, 95% CI 0.2 to 0.5), ≤ 32 mm (0.5%, 95% CI 0.4 to 0.5), and ≥ 36 mm (0.3%, 95% CI 0.3 to 0.4) groups at 8-year follow-up. CONCLUSIONS:The utilization of DM was associated with higher overall revision rates. However, no significant differences in rates of revision for instability were observed among any of the bearing surface groups. These findings may be attributed to surgeons selectively utilizing DM articulations in higher-risk patients.

Periprosthetic joint infections (PJI) are associated with substantial morbidity, affecting between 1 and 2% of patients undergoing a primary joint arthroplasty and approximately 7% of patients undergoing an aseptic joint revision [1]. Management of this condition typically requires prolonged hospital stays, multiple surgical procedures, and long-term antibiotic therapy. Such intensive management is associated with adverse mental health outcomes [2], reductions in overall quality of life [3], and high rates of morbidity [4, 5].

Background: No objective radiographic scoring system exists to classify metaphyseal cone stability. Our purpose was to create a novel, systematic method to radiographically evaluate metaphyseal cone fixation based on radiographic findings suggestive of cone stability. Methods: A retrospective analysis was conducted of revision total knee arthroplasty patients (6/2015-12/2017) using porous titanium femoral or tibial metaphyseal cones in conjunction with short cemented stems (50 mm-75 mm). Minimum follow-up was 2 years. Survivorship free of aseptic loosening and reoperation, as well as radiographic evaluation using a novel cone zone scoring system were analyzed. Results: Forty-nine revision total knee arthroplasties were included in the study (12 femoral, 48 tibial cones), the majority, performed for aseptic loosening (25/49, 51%). Median follow-up was 39 months (range 25-58). Using the radiographic cone zone scoring method, >90% of all femoral cones were classified as likely stable or stable with strong, statistically significant intraclass correlations between all 3 reviewers. Similarly, >97% of all tibial cones were classified as likely stable or stable, with moderate, statistically significant intraclass correlations between all 3 reviewers. Only 1 femoral and 1 tibial cone were considered at risk of loosening. The study sample demonstrated 100% survivorship free of revision for aseptic loosening without evidence of radiographic loosening in any case. Conclusions: Using a novel systematic cone zone scoring and classification method, the overwhelming majority of femoral and tibial cones were classified as likely stable or stable, with no identified cases of aseptic loosening or related revision. Further studies are needed to validate this objective classification method.

Background: Periprosthetic joint infection (PJI) continues to challenge surgeons and patients. The burden of fungal organisms may represent approximately 1% of all PJI. Additionally, fungal PJI is difficult to treat. Most available case series are small and report poor success rates. Fungi are opportunistic pathogens and patients who have fungal PJI are believed to be immunocompromised. Additionally, fungal biofilms are more complex than those formed by other pathogens and confer additional drug resistance. Due to these factors, treatment failure is common. Methods: A retrospective review of our institutional registry was performed to identify patients treated for fungal PJI. There were 49 patients identified with 8 excluded for not having follow-up, which left 22 knees and 19 hips for analyses. Demographics, clinical characteristics, and surgical details were collected. The primary outcome was failure defined as reoperation for infection following the index surgery for fungal PJI within 1 year of the index surgery. Results: Failure occurred in 10 of 19 knees and 11 of the 22 hips. A higher proportion of patients who have extremity grade C failed treatment, and every patient who failed was host grade 2 or 3. The average number of prior surgeries and time from resection to reimplantation were similar between groups. Conclusion: To our knowledge, this represents the largest cohort of fungal PJIs reported in the literature to date. This data supports other literature in that failure rates were high. More study is needed to further understand this entity and improve care for these patients. (c) 2023 Published by Elsevier Inc.

BACKGROUND:Increasingly, dual mobility (DM) articulations have been used in revision total hip arthroplasty (THA), which may prevent postoperative hip instability. The purpose of this study was to report on outcomes of DM implants used in revision THA from the American Joint Replacement Registry (AJRR).METHODS:Revision THA cases performed between 2012 and 2018 Medicare were eligible and categorized by 3 articulations: DM, ≤32 mm, and ≥36 mm femoral heads. The AJRR-sourced revision THA cases were linked to Centers for Medicare and Medicaid Services (CMS) claims data to supplement (re)revision cases not captured in the AJRR. Patient and hospital characteristics were described and modeled as covariates. Using multivariable Cox proportional hazard models, considering competing risk of mortalities, hazard ratios were estimated for all-cause re-revision and re-revision for instability. Of 20,728 revision THAs, 3,043 (14.7%) received a DM, 6,565 (31.7%) a ≤32 mm head, and 11,120 (53.6%) a ≥36 mm head.RESULTS:At 8-year follow-up, the cumulative all-cause re-revision rate for ≤32 mm heads was 21.9% (95%-confidence interval (CI) 20.2%-23.7%) and significantly (P < .0001) higher than DM (16.5%, 95%-CI 15.0%-18.2%) and ≥36 mm heads (15.2%, 95%-CI 14.2%-16.3%). At 8-year follow-up, ≥36 heads had significantly (P < .0001) lower hazard of re-revision for instability (3.3%, 95%-CI 2.9%-3.7%) while the DM (5.4%, 95%-CI 4.5%-6.5%) and ≤32 mm groups (8.6%, 95%-CI 7.7%-9.6%) had higher rates.CONCLUSION:The DM bearings are associated with lower rates of revision for instability compared to patients who had ≤32 mm heads and higher revision rates for ≥36 mm heads. These results may be biased due to unidentified covariates associated with implant selection.