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Background Revision total joint arthroplasties (TJAs) are associated with an increased rate of complications. To date, it is unclear what drives readmission after aseptic revision arthroplasty and what measures can be taken to possibly avoid them. The purpose of this study is to (1) determine the reasons for readmission after aseptic revision TJA and (2) identify patient-specific or postoperative risk factors through a multivariate analysis. Methods A retrospective study examined 1503 cases of aseptic revision TJA between 2009 and 2016 at an urban tertiary care hospital. Eighty-seven cases (5.8%) of readmission within 90 days of index surgery were identified. Bivariate and multivariate analyses were performed to assess independent risk factors for readmission. Results The reasons for readmission were infection (38%), wound complications (22%), and dislocation/instability of the prosthetic joint (13%). Only preoperative anemia was associated with an increased odds ratio (OR) of readmission (OR 1.82, 95% confidence interval [CI] 1.126-2.970, P = .015), whereas postoperative venous thromboembolism prophylaxis with aspirin (OR 0.58, 90% CI 0.340-0.974, P = .039) and discharge to an inpatient rehab facility (OR 0.22, 95% CI 0.051-0.950, P = .042) were associated with significantly lower odds of readmission. Conclusion Based on this single institutional study, addressing preoperative anemia and considering the implementation of aspirin for venous thromboembolism prophylaxis may be 2 targets to potentially reduce readmission after aseptic revision TJA.

Introduction The purpose of our study is to directly compare the rates of instability after revision total hip arthroplasty (THA) between a modular dual mobility (DM) and a conventional polyethylene single-bearing surface. Methods We retrospectively reviewed a consecutive series of patients who underwent revision THA from 2012 to 2016 at a single institution with a minimum of 2 years of follow-up. Rates of re-revision, dislocation, complications, and short-form (SF-12) scores were compared between the DM and single-bearing groups. To control for confounding variables, a multivariate logistic regression analysis was performed. Results Of the 267 revision THA patients, 94 patients had a DM bearing articulation (36%), whereas 173 patients (64%) had a conventional single-bearing with a mean follow-up of 37.8 months (range 24 to 73 months). The DM group was more likely to undergo revision THA for instability compared with the single-bearing group (8.5% versus 1.2%, P ≤ 0.005) but had reduced incidence of postoperative dislocations (2.1% versus 8.7%, P = 0.067) and no difference in the rates of re-revisions (9.6% versus 11.6%, P = 0.770). When controlling for confounding variables, patients who received a DM liner had lower rates of dislocation postoperatively than those of single-bearing (odds ratio 0.12, P = 0.019). Discussion Even with a selection bias of surgeons using DM for patients at high risk of instability, patients undergoing revision THA with a DM bearing have reduced rates of dislocation at the intermediate-term follow-up. Further study is needed to identify any potential longer-term complications which may result from a modular DM bearing.

Purpose Fractures of the distal femur remain challenging to treat, and numerous fixation methods are designed to promote stability and fracture healing. Locking plate constructs have recently become the mainstream fixation method, but debate exists on whether to use locking plates alone or to augment them with interfragmentary screws. This article compares outcomes of distal femur fractures treated with a single locking plate alone versus those treated with a locking plate and interfragmentary screws. Methods We retrospectively reviewed 57 patients treated for distal femur fractures from 2010 to 2013. Patients were divided into two groups: Those treated with a locking plate alone utilizing the minimally invasive plate osteosynthesis (MIPO) technique and those treated with combination of a locking plate and interfragmentary screws using an open technique. Postoperative outcomes were obtained via a manual chart review. Fracture healing and callus indices were evaluated from radiographs. Results 9 patients required revision surgery in the locking plate alone group (6 for persistent nonunion and 3 for varus deformity). Only two patients in the combination group required revisions (both for nonunion). Average time to full weight bearing was 19.54 weeks in the locking plate group versus 14.57 weeks in the combination group (p = 0.004). At the time of full weight bearing, frontal (1.15 versus 1.11, p = 0.004) and sagittal (1.22 versus 1.15, P = 0.008) callus indices were both significantly greater in the locking plate group. Conclusions In this study, the combination of a locking plate and interfragmentary screws achieved suitable stability and a faster time to full weight bearing than using a locking plate alone. Surgeons should consider combining a locking plate with interfragmentary screws as an effective method for fixation of distal femur fractures, particularly in cases when plate fixation alone fails to provide adequate fracture stability.

Background: Postoperative C5 palsy is a common complication following cervical decompression, occurring more frequently after posterior-based procedures. It has been theorized that this is the result of C5 nerve stretch resulting from spinal cord drift with these procedures. As such, it is thought to be less common after anterior cervical decompression and fusion (ACDF). However, no consensus has been reached on its true etiology. The purpose of this study is to assess the rate of C5 palsy following ACDF and to determine whether any radiographic or demographic parameters were predictive of its development. Methods: Two hundred and twenty-six patients who received ACDF between September 2015 and September 2016 were reviewed, and 122 were included in the final analysis. Patient demographic, surgical, and radiographic data were analyzed, including preoperative and postoperative radiographic and motor examination results. The Mann-Whitney U test was used to compare continuous variables between independent groups, and Fisher9s exact test was used to compare categorical variables between groups. Results: Seven patients developed a C5 palsy in the postoperative period, an incidence rate of 5.7%. Among the radiographic parameters evaluated, there were no statistically significant differences between the C5 palsy and nonpalsy groups. Additionally, there were no statistically significant differences in age, patient sex, or numbers of vertebral levels fused between groups. Conclusions: Ultimately, we did not identify any statistically significant demographic or radiographic predictive factors for the development of C5 palsy following ACDF surgery. Level of Evidence: 3.

Background: It is traditionally believed that presence of fungal infection in the nail or skin of patients is a risk factor for subsequent infection. The literature is devoid of any evidence to confirm or refute this belief. This study examined a possible relationship between the presence of superficial skin or nail mycoses and subsequent periprosthetic joint infection (PJI) in patients undergoing total joint arthroplasty (TJA). Methods: This is a single-centre, retrospective study of patients who underwent primary TJA between 2000 and 2018. 55 patients with superficial mycoses of skin or nail, at the time of arthroplasty were identified and a variable number matching with up to a 1:5 ratio was performed with 182 patients undergoing TJA who had no superficial mycosis. The groups were further divided into knee and hip TJA. The outcome of TJA in the cohorts was compared. Results: Preoperative demographics were similar between the 2 groups. The incidence of PJI in patients undergoing TKA within a year was significantly higher in patients with superficial mycosis at 8.6% (3/35) compared to 0% (0/120) in patients without mycosis. However, all infections were caused by bacterial species and none were fungal. Multiple regression analysis demonstrated that the presence of superficial mycosis had a strong correlation with development of PJI postoperatively in our TKA cohort. Conclusions: Identification of fungal infection (mycosis) of skin and nail in patients awaiting TJA is important. These patients appear to have a higher risk for developing bacterial PJI than those without fungal infections. Further study is needed to determine if treatment of these patients prior to arthroplasty stands to reverse the high risk for PJI that these patients carry.

Background Chronic nonsteroidal anti-inflammatory drug (NSAID) use is associated with gastrointestinal bleeding via inhibition of endogenous mucosal protection and platelet aggregation. This study aimed to determine whether extended NSAIDs after joint arthroplasty is associated with increased risk of gastrointestinal bleeding. Methods This was a retrospective study examining 28,794 adults who underwent joint arthroplasty by one of 50 surgeons from 2016 to 2018. Episodes of gastrointestinal bleeding within 90 days postoperatively were identified prospectively. Postoperative medications were reported directly by patients with electronic questionnaires. The primary analysis was performed using binary logistic regression. Results A total of 74 (0.26%) episodes of gastrointestinal bleeding occurred within 90 days (median 8 days) postoperatively. Of 5086 patients with complete data included in the primary analysis, 59.6% had used NSAIDs with median duration of 2 weeks (interquartile range, 0-6 weeks). Patients with gastrointestinal bleeding were significantly older (71.3 vs 67.0 years), required longer hospitalizations (2.1 vs 1.5 days), and more commonly had a history of peptic ulcers (10.8% vs 0.9%). However, there was no positive association between NSAID use and gastrointestinal bleeding. In fact, the odds of gastrointestinal bleeding were lower in patients taking NSAIDs. Gastrointestinal bleeding was associated with anticoagulants, antiplatelet agents, and, to a lesser extent, aspirin. Conclusion NSAIDs were not associated with gastrointestinal bleeding and may be prescribed safely for a majority of patients after joint arthroplasty. The greatest odds of gastrointestinal bleeding occurred in patients with peptic ulcer disease and those who received antiplatelet and anticoagulation agents. Increasing age and bilateral surgery were also associated with gastrointestinal bleeding. Level of Evidence Level III.

Robotic-arm assisted total knee arthroplasty (rTKA) was developed to provide for increased accuracy of component placement compared with conventional manual TKA (mTKA). Whether or not rTKA is cost-effective in a bundled payment model has yet to be addressed. The purpose of this comparative study was to evaluate the short-term clinical outcomes of rTKA and mTKA. We retrospectively reviewed a series of 4,086 consecutive primary TKA performed by one of five surgeons across six different hospitals at our institution from January 2016 to December 2018. Outcomes for rTKA cases (n = 581) and mTKA cases (n = 3,505) were compared using unmatched multivariate analysis and a matched cohort. We analyzed 90-day outcomes, episode-of-care claims data, and short form (SF-12) outcome scores to 2 years postoperatively. In matched bivariate analysis, there was no difference in episode-of-care costs, postacute care costs, complications, 90-day readmission rates, emergency department/urgent care visits, reoperations, and mortality between rTKA and mTKA patients (p > 0.05). Matched patients undergoing rTKA did have a shorter hospital length of stay (1.46 vs. 1.80 days, p

Background Dual mobility (DM) bearings for total hip arthroplasty (THA) have been proposed to reduce the risk of instability in select patients, especially those undergoing revision surgery. The use of DM bearings has not been studied as extensively for use in primary THA. The purpose of this study is to compare outcomes following primary THA with anterior-based approaches between patients receiving DM bearings vs standard bearing hip implants. Methods We retrospectively reviewed a consecutive series of patients undergoing primary THA through an anterior-based approach. A 3:1 propensity score match was performed between the standard and DM bearing patients to control for possible risk factors for instability. Functional outcomes, dislocations, and aseptic revisions were identified for each patient. The effect of DM on postoperative outcomes was determined using univariate statistical analyses. Results In total, 250 DM bearings were compared to 753 standard bearings. We found no difference in dislocation rate between single bearings and DM bearings (0.53% vs 0.4%). There was 1 DM dislocation occurring in a liner with outer diameter of 38 mm. There were no DM dislocations with outer diameter >38 mm. Aseptic revision surgery was more common in DM. This difference was driven by higher incidence of femoral periprosthetic fracture. There were no differences in functional outcomes. Conclusion Dislocation rates are comparably low between DM bearings and standard bearings for THA done using an anterior approach to the hip. Further investigation is needed to determine if specific patient populations may benefit from DM implants for primary THA when an anterior approach to the hip is being used.

Background Revision total joint arthroplasty (TJA) has a higher rate of periprosthetic joint infection (PJI) compared with primary TJA, possibly as the result of increased allogeneic blood transfusion. Tranexamic acid (TXA) is gaining popularity in revision TJA to minimize blood loss and the need for transfusion; however, its effect on PJI reduction has yet to be investigated. The hypothesis of this study was that the administration of TXA during revision arthroplasty is protective against subsequent PJI. Methods A prospectively maintained institutional database was used to identify patients who underwent revision TJA for aseptic failure from 2009 to 2018 and had a minimum follow-up of 90 days. Patients who developed PJI following revision arthroplasty were identified. All patients with PJI met Musculoskeletal Infection Society (MSIS) criteria. A multivariate analysis was performed to identify variables independently associated with PJI after aseptic revision TJA. Results Overall, 1,731 patients who underwent aseptic revision were identified; of these patients, 83 (4.8%) developed PJI. Patients who received TXA had significantly lower rates (p = 0.029) of PJI postoperatively at 3.30% compared with those who did not receive TXA at 5.73%. After controlling for relevant confounding variables, TXA remained a significant independent factor that protected against PJI (odds ratio [OR], 0.47 [95% confidence interval (CI), 0.23 to 0.90]; p = 0.030). Female sex was also identified as a significant independent factor that protected against PJI (OR, 0.52 [95% CI, 0.30 to 0.88]; p = 0.016). However, preoperative anemia was independently associated with an increased risk of subsequent PJI (OR, 2.37 [95% CI, 1.34 to 4.16]; p = 0.003). Conclusions Based on this study conducted at a single institution, the use of TXA during aseptic revision arthroplasty was independently associated with a reduced risk of subsequent acute PJI after adjusting for multiple patient characteristics and surgical factors. Level of evidence Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Background It is unknown whether the outcomes of treatment for periprosthetic joint infection (PJI) are improving with time. This study evaluated trends in PJI treatment outcomes in the hip and knee following 2-stage exchange arthroplasty and irrigation and debridement (I&D) over the last 17 years. Methods We reviewed 550 two-stage exchange arthroplasties and 194 I&Ds between 2000 and 2016 at our institution. Treatment success was defined according to the Delphi consensus criteria and Kaplan-Meier survivorship curves were generated. A multivariate Cox proportional hazards regression model was generated to determine time trends in the outcome of PJI treatment with the year of surgery included as both a continuous covariate (per 1-year increase) and a categorical covariate (2000-2010 or 2011-2016). Results The survivorship of I&D, 2-stage revision, and the total combined cohort were comparable between 2000-2010 and 2011-2016 groups. Multivariate Cox regression analysis showed that the year of surgery was not associated with treatment failure following an I&D or 2-stage exchange arthroplasty, and neither did it increase the risk of non-reimplantation. When year of surgery was considered as a categorical variable, there remained no significant difference in treatment failure following an I&D or 2-stage exchange arthroplasty between the 2000-2010 cohort and 2011-2016 cohort. Conclusion Despite the increasing clinical focus, research advances, and growing literature relating to PJI, we were unable to detect any substantial improvement in the treatment success rates of PJI at our institution over the 17 years examined in this study. Novel treatments and techniques are certainly needed as current and prior strategies remain far from optimal.

Background: Small bowel cancers, specifically duodenal cancer, occur at very low rates but require aggressive surgical resection when diagnosed. An even rarer finding is the presence of intestinal malrotation. Case Presentation: We present the unique case of a patient with both duodenal cancer and partial intestinal malrotation undergoing pancreaticoduodenectomy. We discuss the challenges faced and techniques used to successfully perform a surgical resection in this circumstance. Conclusion: Understanding of intestinal malrotation and review of the imaging is crucial in preparing for a resection of a duodenal tumor in a patient with this condition.

The purpose of our study is to directly compare the rates of instability after revision total hip arthroplasty (THA) between a modular dual mobility (DM) and a conventional polyethylene single-bearing surface.We retrospectively reviewed a consecutive series of patients who underwent revision THA from 2012 to 2016 at a single institution with a minimum of 2 years of follow-up. Rates of re-revision, dislocation, complications, and short-form (SF-12) scores were compared between the DM and single-bearing groups. To control for confounding variables, a multivariate logistic regression analysis was performed.Of the 267 revision THA patients, 94 patients had a DM bearing articulation (36%), whereas 173 patients (64%) had a conventional single-bearing with a mean follow-up of 37.8 months (range 24 to 73 months). The DM group was more likely to undergo revision THA for instability compared with the single-bearing group (8.5% versus 1.2%, P ≤ 0.005) but had reduced incidence of postoperative dislocations (2.1% versus 8.7%, P = 0.067) and no difference in the rates of re-revisions (9.6% versus 11.6%, P = 0.770). When controlling for confounding variables, patients who received a DM liner had lower rates of dislocation postoperatively than those of single-bearing (odds ratio 0.12, P = 0.019).Even with a selection bias of surgeons using DM for patients at high risk of instability, patients undergoing revision THA with a DM bearing have reduced rates of dislocation at the intermediate-term follow-up. Further study is needed to identify any potential longer-term complications which may result from a modular DM bearing.

Background Traditional pain management after total knee arthroplasty (TKA) relies heavily on opioids. Although there is evidence that in-hospital multimodal pain management (MMPM) is more effective than opioid-only (OO) analgesia, there has been little focus on postdischarge pain management. The hypothesis of this study was that MMPM after TKA would reduce pain scores and opioid consumption in the 30-day period after hospital discharge. Methods This is a prospective, 2-group, comparative study with a provider cross-over design comparing a 30-day OO prn regimen with a MMPM regimen and opioid medications prn. The primary outcome measure was visual analog scale pain score and opioid-related side effects. Secondary outcome measures included morphine milligram equivalents consumed, failure of the protocol, and opioid refills. Results There were 216 patients included in the trial, with final data available for 143. There was no clinically meaningful difference in visual analog scale score between the 2 groups at any time. Average opioid consumption at 30 days was 582.5 and 386.4 morphine milligram equivalents for the OO and MMPM cohorts, respectively (P = .0006). Average number of opioid pills consumed at 30 days was 91.8 and 60.4 for OO and MMPM cohorts, respectively (P = .0004). Conclusion A 30-day postdischarge multimodal pain regimen reduced opioid use after TKA while maintaining a similar level of pain control as the OO regimen. OO regimens are at an increased risk of needing additional medications to control pain. Level of Evidence Level II. Registry Name www.clinicaltrials.gov . Trial Number NCT04003350.

Background Although there is an increasing trend toward reporting the outcome of hip and knee arthroplasty separately, it remains unknown whether joint-specific reporting is necessary for periprosthetic joint infection (PJI) as sample sizes are already low, given its relatively rare occurrence. The aim of this study is to compare treatment outcomes of PJI occurring after knee and hip arthroplasty. Furthermore, we aim to establish the necessary follow-up time for an accurate reporting of PJI treatment outcomes. Methods A retrospective study of 792 cases of hip and knee PJI treated with irrigation and debridement or two-stage exchange arthroplasty from 2000 to 2017 was performed. Treatment failure was defined based on the Delphi method–based criteria. The Kaplan-Meier survivorship curves were generated, and a log-rank test was used to evaluate differences in survivorship. A multivariate Cox proportional hazards regression and a sensitivity analysis using propensity matching were performed. A two-piecewise linear regression model was used to examine the threshold effect of time after treatment on survival rates. Results There were no significant differences between hip and knee PJIs in overall survivorship (P = .71), or when stratified by irrigation and debridement (P = .39), or two-stage exchange arthroplasty (P = .59). There was also no difference by joint in the multivariate or sensitivity analysis. Survival rates had the most dramatic rates of decrease in the initial months after treatment of PJI but began to plateau after 1.09 years. Conclusion This study reveals no difference in treatment outcomes between knee and hip PJIs. In addition, given the difficulty with obtaining follow-up, we suggest that one-year follow-up is sufficient for an accurate reporting of treatment failure.

Biofilm-associated implant-related bone and joint infections are clinically important due to the extensive morbidity, cost of care and socioeconomic burden that they cause. Research in the field of biofilms has expanded in the past two decades, however, there is still an immense knowledge gap related to many clinical challenges of these biofilm-associated infections. This subject was assigned to the Biofilm Workgroup during the second International Consensus Meeting on Musculoskeletal Infection held in Philadelphia USA (ICM 2018) (https://icmphilly.com). The main objective of the Biofilm Workgroup was to prepare a consensus document based on a review of the literature, prepared responses, discussion, and vote on thirteen biofilm related questions. The Workgroup commenced discussing and refining responses prepared before the meeting on day one using Delphi methodology, followed by a tally of responses using an anonymized voting system on the second day of ICM 2018. The Working group derived consensus on information about biofilms deemed relevant to clinical practice, pertaining to: (1) surface modifications to prevent/inhibit biofilm formation; (2) therapies to prevent and treat biofilm infections; (3) polymicrobial biofilms; (4) diagnostics to detect active and dormant biofilm in patients; (5) methods to establish minimal biofilm eradication concentration for biofilm bacteria; and (6) novel anti-infectives that are effective against biofilm bacteria. It was also noted that biomedical research funding agencies and the pharmaceutical industry should recognize these areas as priorities. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

One of the methods of radioactive waste management that is receiving considerable attention today is the storage of nuclear waste in geological formations. At present, the geological formation for storage that appears most desirable is the rock salt formation. Although no historical data are available to judge the long-term structural adequacy of such storage in salt, current technology makes it feasible to analyze and design the structure and make reasonable predictions about its performance. It is possible to demonstrate such an analytical technique and to predict the structural behavior of the salt during the operating life of the facility.

This paper summarizes the creep consideration in the design of nuclear waste storage facilities in salt, describes the non-linear analysis method for evaluating the design adequacy, and presents computational results for the current storage design. The application of rock mechanics instrumentation to assure the appropriateness of the design is discussed.It also describes the design evolution of such a facility, starting from the conceptual design, through the preliminary design, to the detailed design stage The empirical design method, laboratory tests and numerical analyses, and the underground in situ tests have been incorporated in the design process to assure the stability of the underground openings, retrievability of waste during the operating phase and encapsulation of waste after decommissioning.