Smokeless Tobacco Use is Associated With Worse Medical and Surgical Outcomes Following Total Hip Arthroplasty.

BACKGROUND: Studies have demonstrated increased complication risk after total hip arthroplasty (THA) in patients who smoke cigarettes. It is unclear if smokeless tobacco use confers a similar impact. The purpose of this study was to (1) evaluate rates of postoperative complications after THA in smokeless tobacco users and people who smoke compared to matched controls, and (2) compare rates of postoperative complications in smokeless tobacco users versus patients who smoke. METHODS: A retrospective cohort study was conducted using a large national database. For patients who underwent primary THA, smokeless tobacco users (n = 950) and people who smoke (n = 21,585) were matched 1:4 with controls (n = 3,800 and 86,340, respectively), and smokeless tobacco users (n = 922) were matched 1:4 with people who smoke (n = 3,688). Joint complication rates within 2 years and medical complications within 90 days postoperatively were compared using multivariable logistic regressions. RESULTS: Within 90 days of primary THA, smokeless tobacco users demonstrated significantly higher rates of wound disruption, pneumonia, deep vein thrombosis, acute kidney injury (AKI), cardiac arrest, transfusion, readmission and longer length of stay compared to tobacco naïve controls. Within 2 years, smokeless tobacco users demonstrated significantly higher rates of prosthetic joint dislocations and overall joint-related complications compared to tobacco naïve controls. CONCLUSION: Smokeless tobacco use is associated with higher rates of medical- and joint-related complications following primary THA. Smokeless tobacco use may be under-diagnosed in patients undergoing elective THA. Surgeons may consider delineating between smoking and smokeless tobacco use during preoperative counseling.

Is American Joint Replacement Registry Data Consistent With International Survivorship in Hip and Knee Arthroplasty? A Comparative Analysis.

BACKGROUND: In collaboration with the Orthopedic Data Evaluation Panel (ODEP), the American Joint Replacement Registry (AJRR) investigated the consistency of hip and knee arthroplasty survivorship results compared to the UK National Joint Registry (NJR). METHODS: A total of three primary knee devices and three primary hip devices were selected by AJRR and ODEP with known variation in performance. Implant manufacturers independently produced Kaplan Meier survivorship based on NJR data and submitted to ODEP for comparison. The AJRR mirrored the methodology, and results from both sources were stratified into three cohorts (all-age, < 65, and ≥ 65 years). RESULTS: There were 42,671 AJRR and 60,439 NJR primary knee cases and 70,169 AJRR and 422,657 NJR primary total hip arthroplasty cases. For TKA, performance between the AJRR and NJR were consistent, showing similar trends for comparatively high and low performing devices. Both PS and CR devices showed statistical agreement in survivorship for all 3 cohorts. Unicompartmental comparison also showed statistical agreement for the Medicare cohort. The all-age and < 65-year-old cohorts showed similar trends and reached statistical agreement through 7 and 6 years. For total hip arthroplasty, performance between the AJRR and NJR were consistent, showing similar trends for comparatively high and low performing devices; 0.18% average difference in survivorship at final follow-up (8 years). One femoral device did not reach statistical agreement but showed only 0.61% difference in survivorship. The remaining acetabular and femoral devices reached statistical agreement in all-ages and through 7 and 8 years in the ≥ 65-year-old cohort. CONCLUSIONS: AJRR and NJR performance trends and survivorship were similar across hip and knee arthroplasty with greatest consistency in the all-age and ≥ 65 cohorts. This focused comparison of survivorship showed encouraging results for reliability of patient outcomes in AJRR compared to the world's largest joint arthroplasty registry which has strong implications for global improvement in patient safety.

Safety Profile of Seven-Day Intra-articular Antibiotic Irrigation for the Treatment of Chronic Periprosthetic Joint Infection: A Prospective Randomized Phase II Comparative Study.

BACKGROUND: Systemic intravenous antimicrobials yield poor outcomes during treatment of periprosthetic joint infection due to the inability to obtain minimum biofilm eradication concentrations. This study evaluated the safety of a novel method of optimized local delivery of intra-articular antibiotics (IAAs). METHODS: This was a Phase II, multicenter, prospective randomized trial evaluating safety of a rapid (seven-day) two-stage exchange arthroplasty with IAA irrigation compared to standard two-stage exchange. The Experimental Group received irrigation using 80 mg tobramycin daily with a 2-hour soak, followed by hourly irrigation using 125 mg vancomycin with a 30-minute soak via an intramedullary irrigation device. The Control Group received an antibiotic-loaded cement spacer with vancomycin (average 8.4 g) and tobramycin (average 7.1 g, total 16 g antibiotics). Both groups received 12 weeks of systemic antibiotics following Stage 2. Safety measures included adverse events, peak vancomycin/tobramycin serum concentrations (Experimental Group), blood transfusion, and mortality. There were thirty-seven patients randomized to the Experimental Group and 39 to control. There was no difference in baseline demographics or comorbidities. RESULTS: There were no antibiotic medication-related adverse events and 2 serious adverse events related to antibiotic instillation. Of 188 vancomycin peak measurements, 69% had detectable serum level concentrations, with all concentrations well below the maximum acceptable trough threshold of 20 µg/mL. Of the 103 tobramycin peak measurements, 45% had detectable levels, with all below the maximum acceptable peak threshold of 18 to 24 µg/mL. There was no difference in blood transfused per subject (Experimental: 655 mL versus Control: 792 mL; P = .4188). There were two (2) deaths in the Experimental Group and four (4) in the control. CONCLUSIONS: The use of IAA is safe with minimal systemic antibiotic exposure. There was no difference in the rates or severity of serious adverse events between groups. Further research is being conducted to examine treatment efficacy.

The Chitranjan S. Ranawat Award: Manipulation Under Anesthesia to Treat Postoperative Stiffness After Total Knee Arthroplasty: A Multicenter Randomized Clinical Trial.

BACKGROUND: Manipulation under anesthesia (MUA) occurs in 4% of patients after total knee arthroplasty (TKA). Anti-inflammatory medications may target arthrofibrosis pathogenesis, but the data are limited. This multicenter randomized clinical trial investigated the effect of adjuvant anti-inflammatory medications with MUA and physical therapy on range of motion (ROM) and outcomes. METHODS: There were 124 patients (124 TKAs) who developed stiffness after primary TKA for osteoarthritis enrolled across 15 institutions. All received MUA when ROM was < 90° at 4 to 12 weeks postoperatively. Randomization proceeded via a permuted block design. Controls received MUA and physical therapy, while the treatment group also received one dose of pre-MUA intravenous dexamethasone (8 mg) and 14 days of oral celecoxib (200 mg). The ROM and clinical outcomes were assessed at 6 weeks and 1 year. This trial was registered with ClinicalTrials.gov. RESULTS: The ROM significantly improved a mean of 46° from a pre-MUA ROM of 72 to 118° immediately after MUA (P < .001). The ROM was similar between the treatment and control groups at 6 weeks following MUA (101 versus 99°, respectively; P = .35) and at one year following MUA (108 versus 108°, respectively; P = .98). Clinical outcomes were similar at both end points. CONCLUSIONS: In this multicenter randomized clinical trial, the addition of intravenous dexamethasone and a short course of oral celecoxib after MUA did not improve ROM or outcomes. However, MUA provided a mean ROM improvement of 46° immediately, 28° at 6 weeks, and 37° at 1 year. Further investigation in regards to dosing, duration, and route of administration of anti-inflammatory medications remains warranted. LEVEL OF EVIDENCE: Level 1, RCT.

The Role of a New Hinged Total Knee Arthroplasty System for Use in a Variety of Complex Knee Scenarios: A Case Series.

Hinged knee arthroplasties are commonly used in scenarios where there are major ligament deficiencies or bone loss around the knee. They are applicable in native knees with major deformities and during revisions. They can also be used as a salvage procedure after distal femoral resection. The new modular hinged device system, namely the Triathlon Hinge Knee (THK) System (Stryker, Mahwah, New Jersey), reflects the advancements of third-generation design and enhances surgical flexibility by allowing streamlined integration with the Triathlon Total Stabilized (TS) System (Stryker, Mahwah, New Jersey) and the Global Modular Replacement System (GMRS, Stryker, Mahwah, New Jersey). Additionally, the Triathlon Revision Tibial Baseplate (Stryker, Mahwah, New Jersey) has been launched as part of THK and is compatible with the Modular Rotating Hinge (MRH , Stryker, Mahwah, New Jersey) femur, which allows the Revision Baseplate to replace the existing tibial component while leaving the existing MRH Femoral Component in place. The Triathlon Revision Tibial Baseplate enables orthopaedic surgeons to use constrained or hinged prostheses, including both distal and total femoral replacement options, without changing the Tibial Baseplate. This is because the TS, MRH, THK, and GMRS femurs are compatible with the new Triathlon Revision Tibial Baseplate. Additionally, the system can be augmented with metaphyseal cone constructs to help provide a stable foundation for reconstruction. This report explores the application of a new modular hinged device system in various scenarios, starting with (1) complex primary hinged knee arthroplasty, followed by revision hinged knee arthroplasty cases including (2) failed TKA with medial collateral ligament (MCL) dysfunction, (3) severe arthrofibrosis post-TKA, (4) revisions for prosthetic joint infection, (5) extensor mechanism deficiency, and (6) arthrofibrosis with extensor mechanism disruption, concluding with a case of (7) distal femoral arthroplasty for periprosthetic fracture post-failed TKA.

Modular Revision System for Complex Hip Revisions: A Case Series.

Revision total hip arthroplasty (THA) is a procedure with many challenges, especially when patients exhibit femoral bone defects. The causes of these defects vary, ranging from removal of prior implants to aseptic loosening. As surgeons navigate these challenges, a reliable surgical system is important. One modular fluted tapered system provides surgeons with tools to address complex hip revision cases. Introduced in 2003, this system has been utilized in over 180,000 procedures, demonstrating its reliability and effectiveness. Previously, the body stem came in sizes 155mm to 235mm. In the discussed case series, we present six distinct patient cases that highlight the advantages and efficacy of a newly introduced modification of the system; that is the use of smaller stemmed components (now 115mm). With each patient presenting unique challenges, we have demonstrated the use of this new short-stem version for multiple applications for various revision scenarios.

Risk Should Not Be a "Four-Letter Word" in Healthcare. Risk and the Future of Musculoskeletal Care.

Orthopaedics has seen a rapid transition to value-based care. As we transition away from fee-for-service models, healthcare systems, groups, and surgeons are being asked to take on an increasing amount of risk. While on the surface risk may have a negative connotation, managing risk allows surgeons to maintain autonomy while taking on value-based care to the next level. The purpose of this paper, the first in a series of 2, is to walk through the impact that value-based care has had on musculoskeletal surgeons, to understand the continued movement healthcare is making into risk sharing models, and to introduce the concept of surgeon specialist-led care.

Cemented Femoral Stem Fixation: Back to the Future.

BACKGROUND: Periprosthetic fractures following elective and nonelective hip arthroplasty remain one of the most common modes of early failure. METHODS: This symposium will explore the current role of cemented fixation and periprosthetic fracture, focusing on history and rationale for cemented stem fixation, registry data, and other potential advantages of cemented stem fixation. A meticulous and methodical surgical technique of cemented stem fixation is paramount to the success and will be thoroughly discussed. RESULTS: The role of stem fixation, and its effect on periprosthetic fracture is well-documented in the literature. Yet despite this, the utilization of cemented stem fixation remains low in the United States. This paradox is multifactorial. CONCLUSION: In addition to a notable reduction in the risk of periprosthetic femur fractures, cemented stem fixation has numerous other advantages and is reproducible with a methodical surgical technique.

A Specialist-Led Care Model: Aligning the Patient and Specialist for the Greatest Impact.

In the previous paper, discussing "Risk and the Future of Musculoskeletal Care," we reviewed the basic concepts of the risk corridor, implications on health care overall if we maintain a fee-for-service model, and the need for musculoskeletal specialists to begin taking on/managing risk to reinforce our presence in a "value-based care" system. This paper discusses the successes and failures of recent value-based care models and provides the framework for the paradigm of a specialist-led care model. We posit that orthopedic surgeons are the most knowledgeable physicians to manage musculoskeletal conditions, create new and innovative models, and lead value-based care to the next level.

High Rate of Intramedullary Canal Culture Positivity in Total Knee Arthroplasty Resection for Prosthetic Joint Infection.

BACKGROUND: Periprosthetic infection is a devastating complication following total knee arthroplasty. A 2-stage protocol often includes an interim antibiotic spacer with intramedullary (IM) dowels. However, the necessity of IM dowels has recently been challenged. Specifically, the data supporting bacterial colonization of the IM canal are limited and controversial. The purpose of this study was to identify the rate of positive IM cultures during resection arthroplasty in periprosthetic knee infection. METHODS: A total of 66 IM diaphyseal cultures were taken during resection arthroplasty from 34 patients diagnosed with periprosthetic knee infection. These IM cultures were taken from the femoral and tibial canals using separate sterile instruments. All patients had infected primary total knee arthroplasty implants at the time of resection. RESULTS: Thirty one percent (n = 21) of IM canal cultures in this study were positive from either the tibial or the femoral diaphysis at the time of resection arthroplasty. There were 18 of 21 (86%) of the positive IM canal cultures with concordant intraoperative joint cultures where the IM cultures matched the intraarticular cultures. CONCLUSION: With a 31% positive IM canal culture rate, this study confirms the logic of using IM dowels with an antibiotic spacer to treat periprosthetic knee infection. Since the failure of a 2-stage reimplantation is catastrophic, any attempt to provide additional local antibiotic delivery seems warranted. Since nearly one-third of our patients had positive IM cultures, this simple addition to an antibiotic spacer has the potential to improve 2-stage results. Claims supporting the elimination of IM dowels during resection arthroplasty seem ill-advised.

Health Policy Views and Political Advocacy of Arthroplasty Surgeons: A Survey of the American Association of Hip and Knee Surgeons Members.

BACKGROUND: The American Association of Hip and Knee Surgeons (AAHKS) is the largest specialty society for arthroplasty surgeons in the United States and is dedicated to education, research, and advocacy. The purpose of this study was to identify the health policy views of AAHKS members and better characterize their advocacy participation. METHODS: A 22 question survey was electronically distributed multiple times via email link to all 3,638 United States members of AAHKS who were in practice or training in 2022. Study results were analyzed using descriptive statistics. RESULTS: There were 311 responses (9%), with 18% of respondents being within 5 years of practice and 38% having more than 20 years of practice. Respondents identified as Republicans (40%), Independents (37%), and Democrats (21%). Top policy issues included preserving physician reimbursement and equitable fee schedule representation (95%), the burden of prior authorization (53%), the impact of Center of Medicare and Medicaid Services regulations (39%), and medical liability and tort reform (39%). Members ranked maintaining appropriate physician reimbursement (44%) and advocating for patients (37%) as the top benefits to participation in advocacy. A majority of respondents (81%) stated that they spend more time on presurgery optimization now than 10 years ago. The most common barrier to advocacy participation was a lack of time (77%). CONCLUSION: Responding AAHKS members are well-informed, politically engaged, patient-oriented, and eager for a voice in policy decisions that affect the professional future of arthroplasty surgeons. These results can be used to help direct strategic efforts of the AAHKS Advocacy Committee to further increase advocacy efforts.

Smokeless Tobacco Use is Associated With Worse Outcomes Following Total Knee Arthroplasty.

BACKGROUND: Studies have demonstrated increased complication risk after total knee arthroplasty (TKA) in patients who smoke cigarettes, but it is unclear if smokeless tobacco use confers a similar impact. The purpose of this study was to (1) evaluate rates of postoperative complications after TKA in smokeless tobacco users and smokers as compared to matched controls, and (2) compare rates of postoperative complications in smokeless tobacco users versus smokers to determine if one is associated with significantly higher rates of postoperative complications. METHODS: A retrospective cohort study was conducted using a national database. For patients who underwent primary TKA, smokeless tobacco users (n = 1,535) and smokers (n = 28,953) were matched at a 1:4 with controls (n = 6,140 and 115,812, respectively), and smokeless tobacco users (n = 1,481) were matched at a 1:4 with smokers (n = 5,924). Rates of joint complications within 2 years and medical complications within 90 days postoperatively were compared using multivariable logistic regressions. RESULTS: After primary TKA, compared to controls, smokeless tobacco users demonstrated significantly higher rates of aseptic loosening/mechanical failure within 2 years, longer lengths of stay, and higher rates of urinary tract infection, pneumonia, deep vein thrombosis, and acute kidney injury within 90 days. Compared to smokers, smokeless tobacco users demonstrated significantly lower rates of aseptic revision and lower rates of wound disruption. CONCLUSION: Smokeless tobacco use is associated with higher rates of both medical and joint complications following primary TKA. However, smoking is associated with higher risk for complications than smokeless tobacco use. LEVEL OF EVIDENCE: Level III.

The Impact of Glucagon-Like Peptide-1 Agonists on Hip and Knee Arthroplasty and Perioperative Considerations.

Glucagon-Like Peptide agonists have traditionally been used for glycemic control in diabetic patients. However, there has been a dramatic rise in their utilization for weight loss management. As such, arthroplasty surgeons will encounter an increasing number of patients on these medications, and therefore it is important to understand the implications of their use in the perioperative period. This review will describe the pharmacological actions of these medications as well as the impact on hip and knee arthroplasty patients, and considerations for perioperative management. Because of the rapid adaption and utilization of these drugs, the science is evolving at a fast pace. More and longer-term studies are needed to truly understand the impact of these medications on total joint arthroplasty utilization and in management of these patients in the perioperative period.

Hypoalbuminemia Predicts Failure of Two-Stage Exchange for Chronic Periprosthetic Joint Infection of the Hip and Knee.

BACKGROUND: Nutritionally compromized patients, with preoperative serum albumin (SAB) < 3.5g/dL, are at higher risk for periprosthetic joint infection (PJI) in total joint arthroplasty. The relationship between nutritional and PJI treatment success is unknown. The purpose of this study was to examine the relationship between preresection nutrition and success after first-stage resection in planned two-stage exchange for PJI. METHODS: A retrospective review was performed on 418 patients who had first-stage resection of a planned two-stage exchange for chronic hip or knee PJI between 2014 and 2018. A total of 157 patients (58 hips and 99 knees) were included who completed first stage, had available preop SAB and had a 2-year follow-up. Failure was defined as persistent infection or repeat surgery for infection after resection. Demographic and surgical data were abstracted and analyzed. RESULTS: Among knee patients with preop SAB >3.5 g/dL, the failure rate was 32% (15 of 47) versus a 48% (25 of 40) failure rate when SAB <3.5 g/dL (P = .10). Similarly, the failure rate among hip patients with preop SAB >3.5 g/dL versus 12.5% (3 of 24) versus 44% (15 of 34) for hip patients with SAB <3.5 g/dL (P = .01). Multivariable regression results indicated that patients with SAB< 3.5 g/dL (P = .0143) and Musculoskeletal Infection Society host type C (P = .0316) were at an increased risk of failure. CONCLUSION: Low preoperative SAB and Musculoskeletal Infection Societyhost type-C are independent risk factors for failure following first-stage resection in planned two-stage exchange for PJI. Efforts to nutritionally optimize PJI patients, when possible, may improve the outcome of two-stage exchange.

Is the American Joint Replacement Registry Able to Correctly Classify Revision Total Knee Arthroplasty Procedural Diagnoses?

BACKGROUND: The American Joint Replacement Registry (AJRR) is a powerful tool for the study of revision total knee arthroplasty (rTKA). The AJRR uses International Classification of Diseases-10 (ICD-10-CM) codes for recording surgical diagnoses. However, the validity of this methodology is unknown. The purpose of this study was to determine the accuracy of ICD-10-CM codes, as used by AJRR, in classifying rTKA diagnoses. METHODS: There were 988 rTKAs performed from 2015 to 2021 identified in our institutional total joint registry (TJR). Revision diagnoses were obtained from TJR, in which trained abstractors prospectively record diagnoses independent of ICD-10-CM data. The ICD-10-CM diagnosis codes submitted to AJRR were retrieved for the same procedures. The accuracy of ICD-10-CM codes for classifying rTKA diagnoses as septic versus aseptic, aseptic loosening, instability, and periprosthetic fracture was assessed using Cohen's Kappa statistics, sensitivities, and specificities. RESULTS: Concordance between AJRR-submitted codes and TJR was excellent (97.3%, k = 0.9) for identifying septic versus aseptic revisions. Agreement for aseptic diagnoses varied from very good for loosening (k = 0.65) and instability (k = 0.64) to fair for periprosthetic fracture (k = 0.36). Specificity was high (> 94%) for all three diagnoses, but sensitivity was lower at 71%, 63%, and 28% for loosening, instability, and periprosthetic fracture, respectively. CONCLUSION: The AJRR submitted ICD-10-CM diagnosis codes correctly classified rTKA cases as septic or aseptic with remarkable accuracy, but accuracy for more granular diagnoses varied. These data demonstrate the potential for diagnosis-specific limitations when using administrative claims data for registry reporting and have important implications for researchers using ICD-10-CM data.

Increased Incidence of Methicillin-Resistant Staphylococcus aureus in Knee and Hip Prosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) is a devastating complication of knee and hip arthroplasty. Past literature has shown that gram-positive bacteria are commonly responsible for these infections, although limited research exists studying the changes in the microbial profile of PJIs over time. This study sought to analyze the incidence and trends of pathogens responsible for PJI over three decades. METHODS: This is a multi-institutional retrospective review of patients who had a knee or hip PJI from 1990 to 2020. Patients with a known causative organism were included and those with insufficient culture sensitivity data were excluded. There were 731 eligible joint infections from 715 patients identified. Organisms were divided into multiple categories based on genus/species and 5-year increments were used to analyze the study period. The Cochran-Armitage trend tests were used to evaluate linear trends in microbial profile over time and a P-value <.05 was considered statistically significant. RESULTS: There was a statistically significant positive linear trend in the incidence of methicillin-resistant Staphylococcus aureus over time (P = .0088) as well as a statistically significant negative linear trend in the incidence of coagulase-negative staphylococci over time (P = .0018). There was no statistical significance between organism and affected joint (knee/hip). CONCLUSION: The incidence of methicillin-resistant Staphylococcus aureus PJI is increasing over time, whereas, coagulase-negative staphylococci PJI is decreasing, paralleling the global trend of antibiotic resistance. Identifying these trends may help with the prevention and treatment of PJI through methods such as remodeling perioperative protocols, modifying prophylactic/empiric antimicrobial approaches, or transitioning to alternative therapeutic strategies.

Dual Mobility Articulation in Revision Total Hip Arthroplasty: An American Joint Replacement Registry Analysis of Patients Aged 65 Years and Older.

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.

Treatment Outcomes of Fungal Periprosthetic Joint Infection.

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.

Can the American Joint Replacement Registry Utilize Administrative Claims Data to Accurately Classify Revision Total Hip Arthroplasty (THA) Surgical Diagnoses?

BACKGROUND: The American Joint Replacement Registry (AJRR) is a valuable tool for studying revision total hip arthroplasty (rTHA). Currently, International Classification of Diseases-10 (ICD-10) codes are utilized by the AJRR for classifying surgical diagnoses. However, the validity of this methodology is unknown. The purpose of this study was to determine the accuracy of these codes, as used by AJRR, in classifying rTHA diagnoses. METHODS: We identified 908 rTHAs performed at our institution from 2015 to 2021 using our total joint registry (TJR). Revision diagnoses were obtained from the TJR, which contains prospectively recorded surgical diagnoses collected by trained abstractors, independent from ICD-10 data. The ICD-10 diagnosis codes, as submitted to AJRR, were retrieved for the same procedures. The accuracy of ICD-10 codes for classifying rTHA diagnoses as septic versus aseptic, instability, aseptic loosening, and periprosthetic fracture was assessed using Cohen's Kappa statistic, sensitivity, and specificity. RESULTS: Concordance between AJRR-submitted data and TJR for classifying rTHA as septic or aseptic was excellent (96.9%; k = 0.87). Agreement for aseptic diagnoses varied from very good for instability (k = 0.76) and loosening (k = 0.67) to moderate for periprosthetic fracture (k = 0.54). Specificity was high (>96%) for all 3 aseptic diagnoses, but sensitivity was lower at 74%, 68%, and 44% for instability, loosening, and periprosthetic fracture, respectively. CONCLUSION: The AJRR submitted ICD-10 data correctly classifies the infection status of rTHA procedures with outstanding accuracy, but the accuracy for more granular diagnoses was variable. These data demonstrate the potential for diagnosis specific limitations when utilizing ICD-10 administrative claims for registry reporting.

Does Treatment at a Specialized Prosthetic Joint Infection Center Improve the Rate of Reimplantation.

BACKGROUND: Two-stage exchange arthroplasty is currently the preferred treatment method for periprosthetic joint infection (PJI). The effectiveness of this strategy in returning patients to premorbid function has recently been challenged. In a review of 18,535 PJI knee patients, 38% did not undergo reimplantation. In another review of 18,156 hip and knee PJI patients, 43% did not undergo reimplantation. These disturbing statistics led us to ask whether treatment at a specialized PJI center could improve the rate of reimplantation compared to the previously noted studies from large national administrative databases. METHODS: A retrospective review of our registry was performed to identify 390 patients who underwent a two-stage exchange after total knee arthroplasty and total hip arthroplasty who had a confirmed chronic bacterial PJI, defined by Musculoskeletal Infection Society criteria, from January 2010 through December 2019. Variables included number of joints resected, number reimplanted, and the number not reimplanted. RESULTS: Of the 390 patients undergoing 2-stage treatment, 386 of 390 (99%) were reimplanted and 4 of 390 (1%) were not reimplanted due to medical issues. CONCLUSION: We have shown that 2-stage treatment at a PJI center significantly improves the rate of reimplantation. A specialized PJI center with experienced revision surgeons doing high volume infection procedures complemented by infectious disease and medical consultants familiar with the special needs of PJI patients may be advantageous. A national network of such centers may have the ability to improve outcomes, standardize treatment protocols, and allow for collaborative research.