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Background: Periprosthetic femur fractures (PPFFs) following total hip arthroplasty (THA) have increased in the past decade as the demand for primary surgery continues to grow. Although there is now more evidence to describe the treatment of Vancouver B fractures, there is still limited knowledge regarding factors that cause surgeons to perform either an open reduction and internal fixation (ORIF) or revision THA (rTHA). The purpose of this study was to determine what type of surgeons treat Vancouver B PPFFs at 11 major academic institutions and if there are trends in treatment decision-making regarding the use of ORIF or rTHA based on surgical training or patient factors. Methods: This multicenter retrospective study evaluated patients surgically treated for Vancouver B PPFF after THA between 2014 and 2019. Patients from 11 academic centers located in the United States were included in this study. Surgical outcomes and patient demographics were evaluated based on surgeon training, surgical treatment type, and institution. Results: Presence of Vancouver B2 (odds ratio [OR]: 0.02, P < .001) or B3 (OR: 0.04, P < .001) fractures were independent risk factors for treatment with rTHA. Treatment by a trauma (OR: 12.49, P < .001) or other-specified surgeon (OR: 13.63, P < .001) were independent risk factors for ORIF repair of Vancouver B fractures. There were no differences in outcomes based on surgeon subspecialty training. Conclusions: This study showed the trends in surgeons who surgically manage Vancouver B fractures at 11 major academic institutions and highlighted that regardless of surgical training or surgical treatment type, postoperative outcomes following management of PPFF were similar.

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Introduction: The failure of total knee arthroplasties (TKA) due to aseptic implant loosening is now the most common cause of long-term failure. Patients with varus alignment of the tibial or femoral component with additional bone collapse are a specific subset. It is unclear, however, whether implant fixation fails first or if bone collapse occurs first. Case Report: A 70-year-old lady with 12-year post-primary total knee arthroplasty presented with limping gate with radiological evidence of medial femoral bone collapse and implant loosening. After appropriate pre-operative planning, intraoperatively, after the removal of loose femoral implant which had additional bone loss and careful removal of a well-fixed tibial implant and to prevent collapse due to bone loss, Stryker LCCK implant with long stems on both sides was used. Additional screws on the medial femoral end, along with cement to fill the gap. After 5 years of follow-up, the patient is doing well with a painless full range of movement of the knee joint. Conclusion: Preoperatively one should always evaluate for bone loss and infection and compare with the other side. In case of aseptic collapse of bones, the use of thicker stems is a good way as these act as weight-sharing implants, and proper cementation during revision TKA is essential.

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This study assesses the comorbidities that are associated with failed revision total ankle arthroplasty (TAA) and explores the outcomes following a failed revision TAA. A retrospective analysis was conducted on a cohort of patients who underwent a revision TAA at a single institution from 2008 to 2022. Patients were identified as having revision failure if they required explantation, below-knee amputation (BKA), or a revision of either metal component. Statistical analysis was performed to identify any significant differences and summarize outcomes. The study included a total of 87 patients who underwent revision TAA with 12 patients who subsequently experienced revision failure. The revision TAA failure rate was 13.8%. There were higher rates of former smokers (58.3%; n = 7) and a history of diabetes (33.3%; n = 4) in the failure cohort, although these differences did not reach statistical significance. Limb salvage procedures were achieved in 11 cases (91.7%). Approaches for failed revision TAAs included arthrodesis (n = 5) with 2 isolated ankle arthrodesis (AA) and 3 tibio-talo-calcaneal (TTC) arthrodesis, an additional revision arthroplasty (n = 6), or amputation (n = 1). Ankle arthroplasty retention was successful in 6 cases (50.0%). Our results demonstrate that a second revision approach was chosen in half of the cases, underscoring its viability as a successful intervention according to patient preferences.Level of Evidence: III.

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Background: Two-stage exchange arthroplasty remains the gold standard for treating chronic hip periprosthetic joint infections. However, controversy remains regarding the optimal spacer type, particularly among patients with increased dislocation risk. This study reports on the outcomes of articulating hip spacers utilizing a single constrained-liner design. Methods: All patients who underwent treatment for hip periprosthetic joint infection at a single institution were screened. Patients were included if they received an articulating spacer utilizing a constrained liner of a single manufacturer design. Indications for constrained liner, demographic variables, and surgical variables were recorded. Patients were assessed for dislocation and component loosening prior to the second stage or at the final follow-up if the second stage was not undertaken. Comparative analysis was performed. Results: Overall, 26 constrained liners were utilized in 25 patients. Indications for constrained liner included history of dislocation (n = 14), massive proximal femoral bone loss (n = 14), greater trochanteric deficiency (n = 12), and absent abductors (n = 7). Many patients had more than one indication. In total, 9 hips (34.6%) underwent a second stage at an average of 7.4 months, while 17 hips never underwent a second stage with an average follow-up of 27.6 months. One patient experienced failure of their constrained liner prior to the second stage due to pelvic discontinuity and massive acetabular bone loss. Conclusions: Utilization of a constrained liner as an articulating spacer is a viable option for patients at high risk of instability. Meticulous cement technique, appropriate component position, and implant selection are crucial in achieving successful outcomes.

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INTRODUCTION: Prolonged length of stay (LOS) following revision total hip arthroplasty (THA) can lead to increased healthcare costs, higher rates of readmission, and lower patient satisfaction. In this study, we investigated the predictive power of machine learning (ML) models for prolonged LOS after revision THA using patient data from a national-scale patient repository. MATERIALS AND METHODS: We identified 11,737 revision THA cases from the American College of Surgeons National Surgical Quality Improvement Program database from 2013 to 2020. Prolonged LOS was defined as exceeding the 75th value of all LOSs in the study cohort. We developed four ML models: artificial neural network (ANN), random forest, histogram-based gradient boosting, and k-nearest neighbor, to predict prolonged LOS after revision THA. Each model's performance was assessed during training and testing sessions in terms of discrimination, calibration, and clinical utility. RESULTS: The ANN model was the most accurate with an AUC of 0.82, calibration slope of 0.90, calibration intercept of 0.02, and Brier score of 0.140 during testing, indicating the model's competency in distinguishing patients subject to prolonged LOS with minimal prediction error. All models showed clinical utility by producing net benefits in the decision curve analyses. The most significant predictors of prolonged LOS were preoperative blood tests (hematocrit, platelet count, and leukocyte count), preoperative transfusion, operation time, indications for revision THA (infection), and age. CONCLUSIONS: Our study demonstrated that the ML model accurately predicted prolonged LOS after revision THA. The results highlighted the importance of the indications for revision surgery in determining the risk of prolonged LOS. With the model's aid, clinicians can stratify individual patients based on key factors, improve care coordination and discharge planning for those at risk of prolonged LOS, and increase cost efficiency.

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BACKGROUND: Surgical techniques in two-stage revision total knee arthroplasty (rTKA) include the use of articulating spacers and static spacers. Shortening of the patellar tendon could be a reason for inferior functional outcomes in two-stage septic rTKA . The aim of this study was to determine if articulating spacers also have negative effects on the extensor mechanism in rTKA. METHODS: This retrospective study includes 65 consecutive patients (23 women, 42 men, age 71.3 ± 1.2; range, 51.2-88.6 years) undergoing septic two-stage rTKA using an articulating spacer between 2014 and 2021 in a single orthopedic center. For all patients, calibrated true lateral radiographs before total knee arthroplasty (TKA) explantation (T0), directly after TKA explantation (T1), shortly before TKA reimplantation (T2) and 6-8 days after TKA reimplantation (T3) were used to calculate the modified Insall Salvati ratio (mISR). RESULTS: Overall, the mISR decreased significantly immediately after explantation (T0 vs. T1, p = 0.002) from 1.43 ± 0.03 to 1.36 ± 0.03 and remained stable until T2 (1.37 ± 0.02, p = 0.74). Following TKA reimplantation, the mISR increased again to 1.43 ± 0.03 (T3). There were no significant differences between T0 and T3 (p = 0.88). Six out of 65 patients (9%) experienced patellar tendon shortening > 10% at T3. CONCLUSIONS: Septic two-stage revision TKA using an articulating spacer does not lead to patellar tendon shortening in the majority of cases. This study suggests that one reason for the improved range of motion after reimplantation may be the use of articulating spacers compared to static spacers.

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Background: The aim of this study was to assess the prevalence, microbiological spectrum, risk factors, and clinical outcomes of unexpected-positive-intraoperative-cultures (UPIC) in presumed aseptic and unclear revision-total-hip-/knee-arthroplasties (rTHA and rTKA) compared to culture-negative (CN) revisions. Methods: This study reviewed all International-consensus-meeting-2018 (ICM 2018) negative or inconclusive rTHA (n = 751) and rTKA (n = 679) performed at our institution from 2011 to 2020 with a minimum follow-up of two years. A Kaplan-Meier-analysis was performed to determine the septic and aseptic-free implant survival in cases with UPIC's and matched culture-negative cases. Patient demographics, risk factors, microbiological spectrum and clinical outcomes were evaluated. Results: There were significantly more UPIC cases in rTHA 196/751 (26.1 %) compared to rTKA 113/679 (16.6 %); (p < 0.001). UPICs in rTKA and rTHA have a lower septic and aseptic implant-free-survival compared to CN revisions. Patients with a history of nickel allergy have a higher risk of an UPIC in rTHA and rTKA (p < 0.001). Septic re-revisions after UPIC had a significantly (H: p = 0.004; K: p = 0.030) shorter time period to the primary/previous surgery (H: 84 (IQR:41-797); K: 115 (IQR:55-446)) compared to patients with aseptic re-revisions after UPIC (H:1248 (IQR:178-3534); K: 827 (IQR:361-1183)). Conclusion: UPICs have a higher rate of septic and aseptic failure than CN outcomes. UPICs are twice as common in rTHA compared to rTKA. Preoperative PJI workup reduces the UPIC rate. Nickel allergy is a risk factor for UPIC. Early revisions with UPICs after primary THA or TKA have a higher risk of septic failure. The translational potential of this article: This article provides new information on revision rates for UPIC and potential risk factors for UPIC and its treatment failure.

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BACKGROUND: A greater Area Deprivation Index (ADI), a tool that gauges socioeconomic disadvantage at the neighborhood level, is associated with worse healthcare outcomes following primary total hip arthroplasty (THA). However, its association with revision THA (rTHA) is unknown. This study aimed to determine the association between ADI and rates of postoperative healthcare resource utilization following rTHA. METHODS: A total of 996 patients who underwent rTHA between 2016 and 2022 were enrolled in a prospective study. The primary outcomes assessed were non-home discharge disposition (DD), length of stay (LOS) ≥ 3 days, 90-day emergency department (ED) visits, and 90-day hospital readmissions. The ADI was calculated using the patient's home address at the time of surgery, with greater ADI indicating greater socioeconomic disadvantage. We evaluated the mediation effect of patient race on ADI and postoperative healthcare utilization using a multivariable logistic regression model. RESULTS: A higher median ADI was revealed for patients who experienced non -home discharge (P = 0.001), extended LOS (P < 0.001), and ED readmission within 90-days of surgery (P = 0.045). When comparing septic versus aseptic rTHA patients, there were significant differences in healthcare resource utilization but no difference in ADI between the two groups. For aseptic rTHA, ADI significantly mediated the effect of race on both non-home DD and LOS ≥ 3 (41% and 46% mediation, respectively). In septic rTHA, ADI mediated 31.1% of the effect of race on non-home DD, but showed minimal mediation effect on LOS. The mediation effect of ADI on ED admission and hospital readmission was minimal for both groups CONCLUSION: Higher ADI scores are associated with increased healthcare utilization after rTHA, including longer hospital stays and more non-home discharges. The ADI significantly mediates the effect of race on these outcomes, particularly in aseptic rTHA cases, suggesting that neighborhood socioeconomic factors play a crucial role in previously observed racial disparities.

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The evaluation, classification, and treatment of significant bone loss after total knee arthroplasty (TKA) continue to be a complex and debated topic in revision TKA (rTKA). Despite the introduction of new evidence and innovative technologies aimed at addressing the approach and care of severe bone loss in rTKA, there is no single document that systematically incorporates these newer surgical approaches. Therefore, a comprehensive review of the treatment of severe bone loss in rTKA is necessary. The Stavros Niarchos Foundation Complex Joint Reconstruction Center Hospital for Special Surgery, dedicated to clinical care and research primarily in revision hip and knee replacement, convened a Management of Bone Loss in Revision TKA symposium on June 24, 2022. At this meeting, the 42 international invited experts were divided into groups; each group was assigned to discuss questions related to 1 of the 4 topics: (1) assessing preoperative workup and imaging, anticipated bone loss, classification system, and implant surveillance; (2) achieving durable fixation in the setting of significant bone loss in revision TKA; (3) managing patellar bone loss and the extensor mechanism in cases of severe bone loss; and (4) considering the use of complex modular replacement systems: hinges, distal femoral, and proximal tibial replacements. Each group came to consensus, when possible, based on an extensive literature review and interactive discussion on their group topic. This document reviews each these 4 areas, the consensus of each group, and directions for future research.

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BACKGROUND: Acetabular bone loss is a major challenge in the setting of revision total hip arthroplasty (THA). Porous tantalum augments have emerged as a viable solution to acetabular bone loss in revision THA. The purpose of this study was to evaluate the survivorship, clinical, and radiological outcomes of these implants. METHODS: We identified 104 augment implants from our retrospective chart review of revision total hip arthroplasty from June 2003 to July 2013. Of these patients, 75 (72.1%) were women, mean age at surgery was 66.2 years (range, 27 to 87); and a mean follow-up was 13.2 years (range, 0.25 to 18.2). Kaplan-Meier survival analysis was performed, with failure defined as revision for aseptic loosening of the acetabular reconstruction. RESULTS: There was significant improvement in the Harris Hip Score from 40.0 to 77.3 (P < 0.001) and the Oxford Hip Score from 14.9 to 36.3 (P < 0.001). Survivorship for failure due to aseptic loosening was 98.8% (95% CI [confidence interval] 96.4 to 100) at 24 months with 60 hips at risk, and 90.4% (95% CI 83.0 to 97.8) at 60 and 120 months with 38 and 18 hips at risk, respectively. The overall rate of all complications was 34 (32.7%). Of these complications, 21 (20.2%) required repeat revision surgery. The revision rate due to aseptic loosening of the augment, infection, dislocation, aseptic loosening of the femoral component, reconstruction failure, and heterotopic ossification was 7 (6.7%), 5 (4.8%), 4 (3.8%), 2 (1.9%), 2 (1.9%), and 1 (0.96%), respectively. CONCLUSION: Treatment of acetabular defects during revision THA using porous tantalum augments provides acceptable implant survivorship and favorable clinical outcomes at mid-term (5-10 year) and long-term (>10 year) follow-up.

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BACKGROUND: The clinical challenge of unexpected positive intraoperative cultures (UPICs) persists in two-stage resection arthroplasty for managing periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA). This study aimed to investigate the incidence of UPICs during the definitive reimplantation phase of two-stage resection arthroplasty of the knee and to assess both the infection- and revision-free survivorship of the implanted prosthesis. METHODS: This retrospective study included 450 two-stage resection arthroplasties of primary knee prostheses performed between January 2012 and April 2017. Patients were excluded if they: (1) underwent three or more staged resections; (2) had ambiguous clinical documentation or deviated from the two-stage protocol; or (3) underwent revision arthroplasty prior to the PJI. Additionally, patients presumed aseptic before the second-stage reimplantation were excluded if they lacked joint aspiration or met the 2011 Musculoskeletal Infection Society (MSIS) criteria for PJI before implantation. RESULTS: After exclusions, 300 patients were analyzed. Among them, 14% had UPIC during the second-stage reimplantation. The follow-up time was 2,316 (range, 1,888 to 3,737) days and 2,531 (range, 1,947 to 3,349) days for UPIC and negative intraoperative culture (NIC) groups, respectively. Re-revision due to subsequent PJI occurred in 26.2% of UPIC patients and 15.1% of NIC patients. The 2-year infection-free survival rates for the NIC, 1 UPIC, and ≥ 2 UPIC cohorts were 99.5, 98.2, and 94.3%, respectively, while the 5-year survival rates were 92.1, 91.1, and 54.3%, respectively. The unfavorable survivorship was significantly different in multiple UPIC cases (P < 0.001). Multiple UPICs with pathogens consistent with the first-stage findings were strongly associated with the risk of reinfection (P < 0.001). CONCLUSIONS: An UPIC was identified in 14% of second-stage reimplantations. Patients who had multiple UPICs demonstrated truncated survivorship and suboptimal outcomes relative to the NIC and single UPIC cohorts, especially with pathogen consistency to the first-stage surgery.

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BACKGROUND: Community deprivation has been linked to poor health outcomes following primary total knee arthroplasty (pTKA), but few studies have explored revision TKA (rTKA). The present study analyzed implications of neighborhood deprivation on rTKA outcomes by characterizing relationships between Area Deprivation Index (ADI) and (1) non-home discharge disposition (DD), (2) hospital length of stay (LOS), (3) 90-day emergency department (ED) visits, (4) 90-day hospital readmissions, and (5) the effect of race on these healthcare outcomes. METHODS: A total of 1,434 patients who underwent rTKA between January 2016 and June 2022 were analyzed. Associations between the ADI and postoperative healthcare resource utilization outcomes were evaluated using multivariate logistic regression. Mediation effect was estimated using a nonparametric bootstrap resampling method. RESULTS: Greater ADI was associated with non-home DD (p < 0.001), LOS ≥ 3 days (p < 0.001), 90-day ED visits (p = 0.015), and 90-day hospital readmission (p = 0.002). Although there was no significant difference in ADI between septic and aseptic patients, septic patients undergoing rTKA were more likely to experience non-home discharge (p < 0.001), prolonged LOS (p < 0.001), and 90-day hospital readmission (p = 0.001). The effect of race on non-home DD was found to be mediated via ADI (p = 0.038). Similarly, results showed the effect of race on prolonged LOS was mediated via ADI (p = 0.01). CONCLUSION: A higher ADI was associated with non-home discharge, prolonged LOS, 90-day ED visits, and 90-day hospital readmissions. The impacts of patient race on both non-home discharge and prolonged LOS were mediated by ADI. This index allows clinicians to better understand and address disparities in rTKA outcomes.

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BACKGROUND: Postoperative delirium (POD) is a common surgical complication. However, the incidence and risk factors associated with postoperative delirium after revision total knee arthroplasty (rTKA) have not been comprehensively explored through extensive national databases. METHODS: Utilizing the National Inpatient Sample (NIS), the largest comprehensive U.S. hospital healthcare database, we undertook a retrospective investigation involving 127,400 patients who underwent rTKA between 2010 and 2019. We assessed various aspects, including patient demographics, hospital characteristics, pre-existing medical conditions, and perioperative complications. RESULTS: The overall incidence of postoperative delirium (POD) in patients undergoing rTKA between 2010 and 2019 was 0.97%. The highest incidence rate of 1.31% was recorded in 2013. Notably, this patient cohort demonstrated advanced age, increased burden of co-morbidities, prolonged hospital stays, increased hospitalization costs, and elevated in-hospital mortality rates (P < 0.001). Moreover, non-elective admissions, non-private insurance payments, and a preference for teaching hospitals were commonly observed among these patients. During their hospitalization, individuals who developed delirium subsequent to rTKA were more prone to experiencing certain perioperative complications. These complications encompassed medical issues like acute myocardial infarction, continuous invasive mechanical ventilation, postoperative shock, sepsis, stroke and other medical problems. Additionally, surgical complications including hemorrhage / seroma / hematoma, irrigation and debridement, prosthetic joint infection, periprosthetic fracture, and wound dehiscence / nonunion were noted. Several risk factors were found to be linked with the development of POD. These included advanced age (≥ 75 years), alcohol abuse, coagulation disorders, congestive heart failure, depression, fluid and electrolyte imbalances, and more. Conversely, female sex, having private insurance, and undergoing elective hospitalization emerged as protective factors against POD. CONCLUSION: Our findings suggest that the general prevalence of POD in rTKA is relatively low according to NIS. There was a significant connection between the POD of rTKA and advanced age, prolonged length of stay (LOS), more in-patients' costs, higher in-hospital mortality rate, increased comorbidities, postoperative medical complications and postoperative surgical complications. This study helps to understand the risk factors associated with POD to improve poor outcomes.

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INTRODUCTION: The increasing prevalence of primary hip arthroplasty has led to a parallel rise in revision cases. Femoral revision often entails compromised bone integrity, requiring consideration of various solutions for optimal reconstructive options. Despite technological advancements, there is limited evidence on the clinical outcomes of the latest modular revision stems. This study aimed to evaluate the clinical outcomes and survival rates of next generation uncemented modular revision stem in patients undergoing hip revision surgery. MATERIALS AND METHODS: This retrospective single-center study assessed the survival and failure causes of a specific uncemented modular stem in 48 patients undergoing hip revision surgery between 2012 and 2022. Data included preoperative parameters, surgical details, and postoperative outcomes measured through clinical and radiographic assessments. Forty-eight patients (25 males, 23 females; mean age 72 years) were included, with a mean Charlson Comorbidity Index of 5. Preoperative diagnoses varied, with periprosthetic joint infection (PJI) being the most common (45.8%), followed by periprosthetic fractures (27.1%). Partial revisions occurred in 60.4%, total revisions in 39.6%. According to Paprosky classification of femoral bone loss, type II and III were the most represented, respectively 35.4% and 50%. RESULTS: At a mean follow-up of 4.6 years, stem survival was 92.5%. Complications (20%) included dislocation, PJI, fracture, and loosening; the overall reoperation rate was 12.5%. The SF-12 physical score was 43.6, while the mental score was 51.1. The HOOS score was 71.8, and the HHS score was 71.4. Radiographic analysis identified nonprogressive osteolysis in 15.1% of patients. CONCLUSIONS: This study on this uncemented modular revision stem demonstrated favorable outcomes in an elder fragile population with moderate to severe femoral bone loss. The implant's modularity provides versatility in addressing various defects, without any implant breakage observed during the study period. Literature comparison highlighted similar outcomes despite sample size differences. The promising results warrant continued investigation into the long-term survivorship of this modular stem system.

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INTRODUCTION: Arthrofibrosis is a common postoperative total knee arthroplasty (TKA) complication that results in limited range of motion (ROM). There is limited literature on outcomes after revision TKA (rTKA) for arthrofibrosis based on preoperative ROM restriction. The aims of this study were to: (1) examine ROM trajectory after rTKA for arthrofibrosis patients who have severe versus non-severe limitations; (2) compare ROM gains and final arc of motion (AOM) between severe and non-severe cohorts; (2a) compare ROM gain in a severe cohort treated with a rotating hinge (RH) versus a non-rotating hinge (non-RH) construct; and (3) assess the impact of arthrofibrosis severity on patient-reported outcome measures (PROMs). METHODS: Patients were divided into 2 groups: Group A had preoperative ROM < 70o (severe), and Group B had preoperative ROM > 70o (non-severe). Patients were assessed clinically using AOM gain, absolute ROM, Knee injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS, JR), Lower Extremity Activity Scale (LEAS), and pain scores. Postoperative gains in AOM were compared between both groups. RESULTS: A total of 56 rTKAs (Group A (severe): n = 36, Group B (non-severe): n = 20) were performed for patients who have postoperative fibrosis. Group B had better ROM at the one-year timepoint (Group B: 95.9 ± 22.5 versus Group A: 83.2 ± 25.7). Group A had significantly better improvement in absolute AOM than Group B (31.1 ± 20.9 versus 11.4 ± 25.0, P < 0.01). The RH group demonstrated significantly better absolute AOM gain than the non-RH group (41.3 ± 19.4 versus 18.3 ± 15.2, P < 0.001). However, there were no significant differences in PROMs between Groups A and B or between RH and NRH groups at the final follow-up. DISCUSSION: Final ROM achieved between severe and non-severe arthrofibrosis groups were similar, and patients who have severe arthrofibrosis can expect greater absolute ROM gains and similar functional outcomes than non-severe arthrofibrosis patients. The RH rTKAs provided greater AOM gains for patients who have severe arthrofibrosis, with equivalent functional outcomes to non-RH implants. For severe arthrofibrosis patients, RH designs provided twice the overall ROM gain, however, longer follow-up is necessary to determine whether RH designs have inferior overall implant survivorship.

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There are instances where a patient's prosthetic hip is unable to be dislocated intraoperatively during a conversion or revision arthroplasty, despite scar removal and standard dislocation maneuvers. We describe a technique that involves an in situ disassociation of the femoral head component from the trunnion without the need for additional osteotomies. This maneuver may be beneficial in cases of protrusio, muscular stiffness, high soft tissue tension, arthrofibrosis, and ankylosis due to heterotopic ossification, as well as cases that involve a large femoral head or acetabular constraint. We also present a case of a 61-year-old male with a chronic prosthetic hip infection who underwent a two-stage revision surgery where this technique was utilized.

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Introduction: The rising use of modular implants in revision total knee arthroplasty offers surgeons greater flexibility in addressing bone defects and achieving uniform gaps compared to monoblock counterparts. However, this enhanced functionality brings specific complications such as loosening and breakage at component coupling sites, leading to challenges due to mechanical failures and suboptimal fixation. Extracting broken components during revision surgery poses a significant challenge, prompting innovative techniques to facilitate extraction. Case Report: We present a rare case of modular femoral component mechanical failure in a 69-year-old male, manifesting as left knee instability and acute pain while walking 4 years following revision of total knee replacement due to infection. Radiographs revealed mechanical failure of the Sigma Total Condylar-III Revision prosthesis bolt, with intra-operative extraction efforts complicated by a lodged broken bolt. Despite initial challenges, successful extraction was achieved using mosquito forceps and a universal nail extractor. Conclusion: This case highlights the importance of documenting rare instances of mechanical failure in modular implants, emphasizing the need to understand prevalence rates and various surgical techniques for implant extraction. Our experience underscores the utility of the universal nail extractor as a valuable tool in managing difficult implant removal during revision surgery. Surgeons must remain vigilant and innovative in addressing challenges encountered during modular implant revisions.

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BACKGROUND: This study used finite element analysis (FEA) to compare the biomechanical stability of bispherical metal augment (BA) and wedge-shaped trabecular-metal augment (TA) in different acetabular defect reconstruction models, thereby explaining the application value of this novel bispherical augment in complex hip revision. METHODS: Three different acetabular defect pelvis models originating from three representative patients with different types of severe acetabular defects (Paprosky IIC, IIIA, and IIIB) were constructed and reconstruction with BA and TA technique was simulated. Based on the FEA models, the displacement of reconstruction implants, relative displacement of bone implants, and hemi-pelvic von Mises stress were investigated under static loads. RESULTS: BA acquired smaller reconstruction system displacement, less relative displacement of bone implants, and lower pelvic von Mises stress than TA in all Paprosky IIC, IIIA, and IIIB defect reconstructions. CONCLUSION: The FEA results show that BA could acquire favourable biomechanical stability in severe acetabular defect reconstruction. This technique is a reliable method in complex hip revision.

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BACKGROUND: The purpose of this study was to determine implant survivorship and functional outcomes for revision total knee arthroplasty (rTKA) with contemporary rotating-hinge knee implants. METHODS: A retrospective review identified 115 rTKAs using contemporary rotating-hinge implants from 2014 to 2018 for the treatment of instability (34, 30%), reimplantation after periprosthetic joint infection (PJI) (33, 29%), aseptic loosening (25, 22%), arthrofibrosis (14, 12%), periprosthetic fracture (4, 3%), osteolysis (4, 3%), and femoral component fracture (1, 1%). There were 70 women (61%), and the mean age was 67 years (range, 27 to 94). The mean follow-up was 3 years (range, 2 to 6). Kaplan-Meier analysis and Cox proportional hazard models estimated survivorship. RESULTS: The re-revision rate was 20% (23 of 115) at an average of 18 months postoperatively. Re-revision indications included PJI (n = 14), aseptic loosening (n = 4), arthrofibrosis (n = 2), instability/malalignment (n = 1), femoral stem fracture (n = 1), and hinge mechanism disruption (n = 1). At 2 and 5 years, survivorship free from all-cause re-revision was 86 and 64%, and survivorship free from re-revision for aseptic loosening was 100 and 87%, respectively. Use of a rotating-hinge implant in reimplantation after PJI was a risk factor for subsequent re-revision (hazard ratio = 2.4, P = 0.046). On a radiographic review of unrevised rotating-hinges, there were major radiolucent lines around 2 femoral and 5 tibial components. The mean Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement increased from 43 preoperatively to 60 at 1 year (P < 0.001). CONCLUSIONS: In patients treated with a rotating-hinge implant for rTKA, there were relatively poor 2-year (86%) and 5-year (64%) survivorship free from all-cause re-revision, most commonly due to PJI. Midterm survivorship free from re-revision for aseptic loosening was modest (87%). There should be a goal to mitigate complications in complex rTKAs with rotating-hinge implants, namely PJI.

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PURPOSE: This study investigates the association between preoperative serum sodium levels and 30-day postoperative complications following aseptic revision total shoulder arthroplasty (TSA). METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried for all patients who underwent aseptic revision TSA from 2015 to 2022. The study population was divided into two groups based on preoperative serum sodium levels: eunatremia (135-144 mEq/L) and hyponatremia (< 135 mEq/L). Logistic regression analysis was performed to investigate the relationship between hyponatremia and early postoperative complications. RESULTS: Compared to eunatremia, hyponatremia was independently associated with a significantly greater likelihood of experiencing any complication (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.14-2.40; P = .008), blood transfusions (OR 2.45, 95% CI 1.24-4.83; P = .010), unplanned reoperation (OR 2.27, 95% CI 1.07-4.79; P = .032), and length of stay > 2 days (OR 1.63, 95% CI 1.09-2.45; P = .017). CONCLUSION: Hyponatremia was associated with a greater rate of early postoperative complications following noninfectious revision TSA. This study sheds light on the role of preoperative hyponatremia as a risk factor for postoperative complications and may help surgeons better select surgical candidates and improve surgical outcomes in the setting of revision TSA.

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