Revision Total Hip Research Articles

Parametric analysis of the effect of impaction load on the stability of head-neck junction in total hip arthroplasty

BackgroundTribocorrosion at head-neck interface is one of the main causes leading to the failure of hip implants in total hip arthroplasty. Impaction load has been acknowledged as one of the key factors influencing the stability of the taper junction. It is understood that the magnitude of impaction force differs from the surgeon to surgeon in primary total hip arthroplasty or revision. Clinically, it is sufficient enough to keep the male and female tapers inseparable utilizing a low impaction, which seems to contradict previous researches. The objective of this study was to investigate the effect of impaction loads on the stability of taper junction during assembly and gaits. MethodsA finite element model with 12/14 taper and the taper mismatch of 4′ was developed for investigation. The impaction force profiles were collected from surgeon as the inputs, and then the contact mechanics over one or multiple gaits was further analyzed and validated utilizing hip simulator test. FindingsImpaction force ranging from 200 to 2000 N could provide the same taper connection effect after the first gait due to the secondary seating. As for impaction loads of 3000 N and above, an increased impaction force would lead to the tighter taper connection. InterpretationThe effect of impaction load on the stability of head-neck junction is a piecewise function, indicating that the stability of taper junction is not affected by different impaction loads and tends to be consistent while its magnitude is below the threshold. Instead, the stability of taper junction is positively correlated with impaction force.

Systematic Review and Meta-Analysis of Intrawound Vancomycin in Total Hip and Total Knee Arthroplasty: A Continued Call for a Prospective Randomized Trial

BackgroundPeriprosthetic joint injection (PJI) is a rare, but life-altering complication of total joint arthroplasty (TJA). Though intrawound vancomycin powder (IVP) has been studied in other orthopedic subspecialties, its efficacy and safety in TJA has not been established. MethodsPubMed and MEDLINE databases were used to identify studies utilizing IVP in primary and revision total hip (THA) and knee arthroplasty (TKA). Postoperative PJI data were pooled using random effect models with results reported as odds ratios (ORs) and 95% confidence intervals (CIs). Studies were weighted by the inverse variance of their effect estimates. ResultsOverall, 16 of the 1871 studies identified were pooled for final analysis, yielding 33,731 patients totally. Of these, 17 164 received IVP. In aggregate, patients who received IVP had a decreased rate of PJI (OR 0.46, P < .05). Separately, TKA and THA patients who received IVP had lower rates of PJI (OR 0.41, P < .05 and OR 0.45, P < .05, respectively). Aggregate analysis of primary TKA and THA patients also revealed a decreased PJI rate (OR 0.44, P < .05). Pooled revision TKA and THA patients had a similar decrease in PJI rates (OR 0.30, P < .05). Although no publication bias was appreciated, these findings are limited by the low-quality evidence available. ConclusionWhile IVP may reduce the risk of PJI in primary and revision TJA, its widespread use cannot be recommended until higher-quality data, such as that obtained from randomized control trials, are available. This study underscores the continued need for more rigorous studies before general adoption of this practice by arthroplasty surgeons.

Differences in Patient-Reported Outcome Measures Between Primary and Revision Total Hip Arthroplasty: Realistic Patient Expectations for Patients With Low Baseline Activity.

Primary total hip arthroplasty (pTHA) and revision total hip arthroplasty (rTHA) are not often compared in terms of patient-reported outcome measures (PROMs). However, surgeons and patients need to better understand the differences in PROMs between primary and revision surgery to set realistic patient expectations and recovery milestones. A matched cohort study of pTHA to rTHA was performed with our arthroplasty database of a single surgeon's experience from 2012 to 2018. There was a significant difference in both pre-operative assessment and change from preoperative to postoperative assessment of the PROMs. Patients undergoing pTHA had higher visual analog scale (VAS) pain scores (67.9 vs 57.9, P=.004). Those undergoing rTHA had higher Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (57.1 vs 50.1, P=.008) and Veterans RAND 12 Item Health Survey (VR-12) (33.5 vs 33.1, P=.01) scores. However, a significant change was noted in the difference from preoperative to postoperative scores between the pTHA and rTHA groups: Harris Hip Score (HHS) total score (pTHA 30.7 vs rTHA 4.4, P<.001), WOMAC score (pTHA 29.3 vs rTHA 12.2, P<.001), and VAS pain score (pTHA -48.3 vs rTHA -26.5, P<.001) as well as groin pain (pTHA 1.4% vs rTHA 7.1%, P=.02). Further, PROMs after rTHA were inferior to those after pTHA with several outcome instruments, including HHS, WOMAC score, and VAS pain score. In addition, groin pain was significantly greater in the rTHA cohort compared with the pTHA cohort at the latest follow-up. This study allows surgeons and patients to better understand the differences in PROMs to set realistic patient expectations and recovery milestones. [Orthopedics. 2022;45(4):251-255.].

How Should Antibiotics Be Used in Primary and Revision Hip and Knee Arthroplasty? An Introduction

Joint arthroplasty is a highly successful surgical treatment for symptomatic arthritis of the hip and knee. Despite excellent pain relief and prosthesis survival of approximately 90% at 20 years, complications occur [[1]Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)Hip, Knee & Shoulder Arthroplasty: 2021 Annual Report. AOA, Adelaide2021: 1-432https://aoanjrr.sahmri.com/annual-reports-2021Google Scholar]. Deep periprosthetic joint infection (PJI) is among the top 2 causes of failure around the world after primary and revision, hip and knee replacement at both short-term and long-term follow-up [1Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR)Hip, Knee & Shoulder Arthroplasty: 2021 Annual Report. AOA, Adelaide2021: 1-432https://aoanjrr.sahmri.com/annual-reports-2021Google Scholar, 2Meyer J.A. Zhu M. Cavadino A. Coleman B. Munro J.T. Young S.W. Infection and periprosthetic fracture are the leading causes of failure after aseptic revision total knee arthroplasty.Arch Orthop Trauma Surg. 2021; 141: 1373-1383Crossref PubMed Scopus (9) Google Scholar, 3Le D.H. Goodman S.B. Maloney W.J. Huddleston J.I. Current modes of failure in TKA: infection, instability, and stiffness predominate.Clin Orthop Relat Res. 2014; 472: 2197-2200Crossref PubMed Scopus (183) Google Scholar]. In distinction to many other problems, such as dislocation and polyethylene wear that can be directly influenced by improvements in surgical technique and prosthesis design, surgeons may find it more frustrating to reduce surgical site infections. It is important to remember that appropriate use of prophylactic antibiotics, introduced over 50 years ago, remains the single most effective intervention available [[4]Burke J.F. The effective period of preventive antibiotic action in experimental incisions and dermal lesions.Surgery. 1961; 50: 161-168PubMed Google Scholar]. In our well-intentioned pursuit of completely eliminating PJI we can sometimes fall victim to the more is better philosophy. Indeed, over the past few years we have seen the introduction of new delivery methods, dosing schedules, and adjunctive products that encourage us to expand our use of prophylactic antibiotics without conclusive evidence. Additionally, our own success has led us to implement change before results from level 1A studies are available. Although PJI remains a persistent concern, the absolute rate of PJI after hip and knee arthroplasty remains low. Consequently, proving the value of new interventions remains problematic due to the large number of patients and extended follow-up duration required for definitive studies [[5]Thompson K.M. Oldenburg W.A. Deschamps C. Rupp W.C. MD Smith C.D. Chasing zero: the drive to eliminate surgical site infections.Ann Surg. 2011; 254: 430-436Crossref PubMed Scopus (65) Google Scholar]. Furthermore, the distinctions among prophylactic, treatment, and suppressive use of antibiotics have become blurred at times. It is important to remember that overuse of antibiotics has potentially significant consequences including the emergence of antibiotic resistance at the individual and societal levels, and individual patient side effects that can have serious consequences, such as acute kidney injury and allergic reaction [[6]Kheir M.M. Dilley J.E. Ziemba-Davis M. Meneghini R.M. The AAHKS clinical research award: extended oral antibiotics prevent periprosthetic joint infection in high-risk cases: 3855 patients with 1-Year follow-up.J Arthroplasty. 2021; 36: S18-S25Abstract Full Text Full Text PDF PubMed Scopus (20) Google Scholar]. In this series of papers, drawn from presentations from the AAHKS Annual Meeting Symposium: Antibiotic Use in Primary and Revision Total Hip and Knee Arthroplasty, we will discuss the most effective uses of antibiotics before, during, and after surgery in order to reduce deep PJI. Each paper, authored by an expert in the field, will summarize the published data and clinical guidelines pertinent to the topic and distill the information to pragmatic advice that is ready for use in your practice. Download .docx (.02 MB) Help with docx files Conflict of Interest Statement for Clarke

Patient-reported outcome after primary and aseptic revision hip arthroplasty: 1-year follow-up of 3,559 primary and 406 revision THAs in an institutional registry.

Background and purposePatient-reported outcomes (PROMs) after primary total hip arthroplasty (THA) and revision THA are important information in the preoperative shared decision-making process. We present 1-year results on pain, function, and quality of life following primary and revision THA.Patients and methodsFrom 2010 to 2018, 3,559 primary THA and 406 revision THAs were included in our institutional quality registry. PROMs were registered preoperatively, 3 months, and 1 year after surgery, numeric rating scale (0–10) for pain during mobilization and at rest, health-related quality of life (EQ-5D), and a hip-specific physical function score (HOOS-PS). 2 anchor questions were asked 1 year after surgery concerning joint function and willingness to go through surgery again.ResultsThere were statistically significant improvements in all PROMs at the 3-month follow-up in both groups. All PROMs improved more in the primary group relative to the revision group. 1 year after surgery, pain during mobilization was reduced with a mean change of 5.1 (SD 2.6) for primary THA and 2.9 (SD 3.0) for revision THA. 93% of primary THA patients reported both better function 1 year after surgery and that they would have gone through surgery again, compared with 78% and 79% in the revision THA group.InterpretationPrimary THA patients reported better function and more pain relief than the revision THA group 1 year after surgery. Pain during mobilization shows the most marked improvement in both groups, which is important preoperative information for patients.

Elective lower limb orthopedic arthroplasty surgery in patients with pulmonary hypertension.

Patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension (PH) are at increased risk when undergoing anesthesia and major surgery. Data on outcomes for elective orthopedic surgery in patients with PH are limited. A patient pathway was established to provide access to elective lower limb arthroplasty. This included assessment of orthopedic needs, fitness for anesthesia, preoperative optimization, and intra‐ and postoperative management. Patient data were retrospectively retrieved using patient's hospital records. Between 2012 and 2020, 29 operations (21 total hip replacements [THRs], 7 total knee replacements [TKRs], 1 total hip revision) were performed in 25 patients (mean age: 67 years). Perioperatively, 72% were treated with low‐dose intravenous prostanoid. All had arterial lines, and central access and perioperative lithium dilution cardiac output monitoring was used in 86% of cases. Four patients underwent GA, 21 spinal anesthesia, and 4 CSE anesthesia. Supplemental nerve blocks were performed in all patients undergoing general, and 12 of 21 undergoing spinal anesthesia. All were managed in high dependency postoperatively. Hospital length of stay and complication rates were higher than reported in non‐PH patients. Perioperative complications included hypotension requiring vasopressors (n = 10), blood transfusion (n = 7), nonorthopedic infection (n = 4), and decompensated right heart failure (n = 1). There was no associated mortality. All implants were functioning well at 6 weeks and subsequent follow‐up. EmPHasis‐10 quality of score decreased by 5.5 (±2.1) (p = 0.04). A dedicated multiprofessional pathway can be used to safely select and manage patients with PH through elective lower limb arthroplasty.

The Potential Value of Monocyte to Lymphocyte Ratio, Platelet to Mean Platelet Volume Ratio in the Diagnosis of Periprosthetic Joint Infections.

ObjectiveTo explore the possibility of obtaining more accurate information from routine blood tests for the diagnosis of periprosthetic joint infection (PJI).MethodsThis is a retrospective study. Between 2017 and 2018, a total of 246 patients who underwent total hip or knee revision surgery were included in this study. There were 146 females and 100 males, and the mean age of the patients was 62.1 ± 12.75 years. Laboratory parameters erythrocyte sedimentation rate (ESR), C‐reactive protein (CRP), D‐dimer, plasma fibrinogen, serum white blood cell (WBC), and calculable ratio markers were collected. Based on leukocytes (monocyte count, neutrophil count, lymphocyte count), platelet count, and mean platelet volume Inflammation‐related ratio markers were calculated, which including monocyte to lymphocyte ratio (MLR), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), and platelet to mean platelet volume ratio (PMR). Follow‐up of all studied cases for at least 1 year. The diagnostic value of the markers based on the receiver operating characteristic (ROC) analysis. The most optimal combinations of blood markers were selected by the prediction models. Statistical analyses and prediction models were performed using R software.ResultsOf the 246 patients, 125 were diagnosed with PJI and 121 with aseptic loosening. A higher rate of patients underwent revision surgery due to hip prosthesis loosening in the aseptic loosening group (74.4%) compared to the PJI group (45.6%, P < 0.001). ROC curves showed that the area under the curve (AUC) for classical markers, fibrinogen was 0.853 (95% confidence interval [CI], 0.805–0.901), ESR was 0.836 (95% CI, 0.785–0.887) and CRP was 0.825 (95% CI, 0.773–0.878). Followed by the PMR, PLR, NLR and MLR, which showed promising diagnostic performance with AUCs of 0.791, 0.785, 0.736, and 0.733. The AUCs of the ratio markers were higher than those of D‐dimer (0.691;95% CI, 0.6243–0.7584) and serum WBC (0.622; 95% CI, 0.552–0.691). After the predictive model calculation, AUC was up to 0.923 (95% CI, 0.891–0.951) when plasma fibrinogen combined with MLR and PMR and interpreted excellent discriminatory capacity with a sensitivity of 86.40% and a specificity of 84.17%. The new combination significantly increases the accuracy and reliability of the diagnosis of PJI (P < 0.001). The AUC increased to 0.899 (95% CI, 0.861–0.931; P = 0.007) and 0.916 (95% CI, 0.880–0.946; P < 0.001), followed by CRP and ESR, respectively. All plasma fibrinogen, ESR, and CRP combined with both PMR and MLR achieved the highest specificity (89.17%) and PPV (85.34%).ConclusionThe diagnostic performance greatly improved when plasma fibrinogen, ESR, and CRP combined with ratio markers.

Total Hip and Knee Revisions are Really Outpatient Procedures? Implications of the Removal From the Inpatient Only List

BackgroundIn 2021, the Centers for Medicare and Medicaid Services (CMS) removed over 200 procedures from the Inpatient Only (IPO) list including revision total hip (THA) and total knee arthroplasties (TKA). The purpose of this study is to determine if some revision TKA and THA procedures may be appropriate for outpatient status. MethodsWe reviewed a consecutive series of 1026 revision THA and TKA patients at our tertiary academic institution from 2015 to 2020. An outpatient procedure was defined as a length of stay of <2 midnights. We queried our prospectively collected arthroplasty database and compared demographics, comorbidities, surgical indication, type of procedure, discharge disposition, readmissions, and complications between the outpatient and inpatient groups. ResultsThere were only 166 revision patients (16%) who met outpatient criteria. Revision THA outpatients were more likely to have a head and liner exchange (49% vs 25%, P < .001) and an indication of instability (93% vs 44%, P < .001). Revision TKA outpatients were more likely to have an isolated liner exchange (34% vs 14%, P < .001) and have an indication of instability (67% vs 25%, P < .001). Patients undergoing a revision for infection and aseptic loosening were more likely to require an inpatient stay than other revision indication (P < .05). ConclusionThe vast majority of revision TKA and THA patients met CMS inpatient criteria. In addition to a projected decrease in facility reimbursement, concerns exist for the safety of early discharge and access to care for these complex patients if CMS removes all revisions from the Inpatient Only list.

Procedures With Longer Intraoperative Times Undervalue Surgeon Work in Total Joint Arthroplasty: A Large, Nationwide Database Study.

Work relative value units (wRVUs) measure a surgeon's time and intensity required to perform the pre-service, intra-service, and post-service work of a surgical procedure and are commonly used to compare a physician's work between different procedures. Previous literature across multiple specialties report that longer, often revision, operations are undervalued when compared to primary procedures. Our study aims to analyze the differences in intra-operative time, and its corresponding wRVU/h between the Medicare benchmarks and real-world time-stamped data for total joint arthroplasty procedures. Thirteen primary and revision hip and knee arthroplasty procedures were identified, and intra-operative times were collected using the National Surgical Quality Improvement Program databases from 2014 to 2019. The Relative Value Scale Update Committee's (RUC) estimated median intra-operative times for each procedure was compared to the calculated median intra-operative times from National Surgical Quality Improvement Program, as were their corresponding wRVU/h. Procedures were additionally stratified by "long" (>110minutes) and "short" (≤110minutes) intra-operative times. The RUC over-estimated intra-operative time by 35.24% on average and this overestimation was more profound in longer operations than shorter operations (47.75% vs 15.22%, P= .011). The RUC intensity per unit time values (wRVU/h) between "long" and "short" procedures were significantly different (P<.001) and showed the undervaluation of intensity for the longer procedures by an average of 3.47 wRVU/h. Our study provides further evidence that physician work is undervalued in revision total hip and knee surgeries.

The effect of the COVID-19 pandemic on revision total hip and knee arthroplasty at a large academic hospital network

We sought to quantify the impact of COVID-19 on canceled revision total joint arthroplasty (TJA) in a large academic hospital network. We performed a retrospective analysis of revision TKA and THA in a healthcare system containing 5 hospitals in a time period of 8 months prior to and 8 months after the cessation of elective surgery. We found a 30.1% decrease in revision TKA and a 6.80% decrease in revision THA. Revision TJA volume decreased in our healthcare system during COVID-19 compared to prior to the pandemic, which will likely have lasting financial and clinical ramifications for the healthcare system.

CoCrMo-Nanoparticles induced peri-implant osteolysis by promoting osteoblast ferroptosis via regulating Nrf2-ARE signalling pathway.

ObjectivesAseptic loosening (AL) is the most common reason of total hip arthroplasty (THA) failure and revision surgery. Osteolysis, caused by wear particles released from implant surfaces, has a vital role in AL. Although previous studies suggest that wear particles always lead to osteoblast programmed death in the process of AL, the specific mechanism remains incompletely understood and osteoblast ferroptosis maybe a new mechanism of AL.Materials and MethodsCoCrMo nanoparticles (CoNPs) were prepared to investigate the influence of ferroptosis in osteoblasts and calvaria resorption animal models. Periprosthetic osteolytic bone tissue was collected from patients who underwent AL after THA to verify osteoblast ferroptosis.ResultsOur study demonstrated that CoNPs induced significant ferroptosis in osteoblasts and particles induced osteolysis (PIO) animal models. Blocking ferroptosis with specific inhibitor Ferrostatin‐1 dramatically reduced particle‐induced ferroptosis in vitro. Moreover, in osteoblasts, CoNPs significantly downregulated the expression of Nrf2 (nuclear factor erythroid 2‐related factor 2), a core element in the antioxidant response. The overexpression of Nrf2 by siKeap1 or Nrf2 activator Oltipraz obviously upregulated antioxidant response elements (AREs) and suppressed ferroptosis in osteoblasts. Furthermore, in PIO animal models, the combined utilization of Ferrostatin‐1 and Oltipraz dramatically ameliorated ferroptosis and the severity of osteolysis.ConclusionsThese results indicate that CoNPs promote osteoblast ferroptosis by regulating the Nrf2‐ARE signalling pathway, which suggests a new mechanism underlying PIO and represents a potential therapeutic approach for AL.

Results of Acetabular Microfracture in Patients undergoing FAI surgery are Strongly Correlated with Age (142)

Objectives:Full-thickness cartilage injury is not uncommon in patients undergoing primary treatment of Femoroacetabular impingement (FAI). Treatment of these lesions with microfracture is commonly performed. However, the outcomes of these procedures relative to other patients undergoing FAI surgery is not well established and the literature on this topic is limited to small, retrospective single surgeon studies. The purpose of the present study was to evaluate outcomes of patients who underwent concurrent FAI correction and acetabular microfracture and to identify predictors treatment failure.Methods:A prospective multicenter cohort study of the treatment of FAI was performed. A total of 760 hips undergoing primary FAI surgery were enrolled. Inclusion criteria were primary FAI surgery, Tonnis 0 or 1 osteoarthritis grade, and age between 16 and 55 years. A total of 61 hips underwent treatment of full-thickness acetabular cartilage lesions with microfracture, with 55 (90.2%) having follow-up greater than 1 year (mean 4.0 years). This group had a mean age of 35.0+10.1 years, BMI of 27.2+4.2, and included 81.8% (45/55) males. A comparison cohort of 492 hips undergoing primary FAI surgery without treatment of acetabular full-thickness cartilage was utilized. Baseline, intraoperative, and follow-up data was recorded including the modified Harris hip score (mHHS) and HOOS domains of pain, ADLs, sports and recreation, symptoms, and quality of life. Composite failure was characterized by reoperation [total hip arthroplasty (THA) or revision surgery] or clinical failure (failure to meet either MCID or PASS for mHHS). Age was assessed in 5 year intervals. Students t-test was used for continuous variables and chi squared were used for categorical variables. A p value less than 0.05 was considering significant.Results:Hips undergoing acetabular microfracture were more likely (compared to comparison cohort) to be male (81.8% vs. 40.9%, p<.001) older (35.0 vs. 29.9 years, p=0.001), had higher BMI (27.2 vs. 25.0, p=.001), and greater alpha angle (69.6 vs. 62.3, p<.001). In the microfracture cohort, 12.7% of patients progressed to THA (compared to 3.0% in comparison cohort, p=.001), while the rate of composite failure was similar to the comparison cohort (29.1% vs. 26.0%, p=.618). Age was highly correlated with the risk of THA and composite failure. The rate of THA for patients <35, 35-40*, and >40 years* of age was 0%, 20.0%, and 22.7% p=.016*), while the rate of composite failure in these groups was 17.4%, 20.0% and 45.5%, respectively (p=.029*). Hips greater than 35 years of age demonstrated inferior HOOS outcomes for domains of pain, ADLs, sports and recreation, QOL, and symptoms and SF-12 physical component scores(Table 1).Conclusions:The results of acetabular microfracture in patients undergoing FAI surgery at a mean follow-up of 4.0 years postoperatively are strongly correlated with age. Patients under 35 years of age demonstrate excellent outcomes with low rates of revision or progression to THA. Acetabular microfracture should have a limited to absent role in patients over the age of 40.

A study on finite element analysis methodologies and approaches used for total hip arthroplasty

The continuously increasing necessities of total hip arthroplasty (THA) and revision hip arthroplasty (RHA) due to the worldwide increasing aging population and increased accident rates have caught the attention of researchers for improving the biological and mechanical performances of transplanted hip implants. There has been an excessive amount of research works in this context in the last few decades using finite element analysis (FEA). This review article aimed to identify the major criteria and approaches that FEA can implement so that superior performances from hip implants can be obtained. The study revealed some important areas and approaches such as geometrical design, topology optimization, utilization of beneficial materials, functional grading of materials (FGM), and helpful coating layers that can be optimized for improving the performances of hip implants. Furthermore, the study focused on defining suspected failure regions and the role of fixation devices in reducing the failure of the hip implant prosthesis.

Deciphering the low abundance microbiota of presumed aseptic hip and knee implants.

16S rRNA gene sequencing of DNA extracted from clinically uninfected hip and knee implant samples has revealed polymicrobial populations. However, previous studies assessed 16S rRNA gene sequencing as a technique for the diagnosis of periprosthetic joint infections, leaving the microbiota of presumed aseptic hip and knee implants largely unstudied. These communities of microorganisms might play important roles in aspects of host health, such as aseptic loosening. Therefore, this study sought to characterize the bacterial composition of presumed aseptic joint implant microbiota using next generation 16S rRNA gene sequencing, and it evaluated this method for future investigations. 248 samples were collected from implants of 41 patients undergoing total hip or knee arthroplasty revision for presumed aseptic failure. DNA was extracted using two methodologies—one optimized for high throughput and the other for human samples—and amplicons of the V4 region of the 16S rRNA gene were sequenced. Sequencing data were analyzed and compared with ancillary specific PCR and microbiological culture. Computational tools (SourceTracker and decontam) were used to detect and compensate for environmental and processing contaminants. Microbial diversity of patient samples was higher than that of open-air controls and differentially abundant taxa were detected between these conditions, possibly reflecting a true microbiota that is present in clinically uninfected joint implants. However, positive control-associated artifacts and DNA extraction methodology significantly affected sequencing results. As well, sequencing failed to identify Cutibacterium acnes in most culture- and PCR-positive samples. These challenges limited characterization of bacteria in presumed aseptic implants, but genera were identified for further investigation. In all, we provide further support for the hypothesis that there is likely a microbiota present in clinically uninfected joint implants, and we show that methods other than 16S rRNA gene sequencing may be ideal for its characterization. This work has illuminated the importance of further study of microbiota of clinically uninfected joint implants with novel molecular and computational tools to further eliminate contaminants and artifacts that arise in low bacterial abundance samples.

Total hip revision with custom-made spacer and prosthesis: A case report

BACKGROUNDBoth periprosthetic joint infections (PJIs) and severe femoral segmental defects are catastrophic complications of total hip arthroplasty (THA), and both present a significant challenge in revisional surgery. There are limited data available to guide clinical decision making when both occur concurrently. CASE SUMMARYA 61-year-old woman presented with a 6-mo history of a sinus tract at the site of her original THA incision. Radiological imaging revealed a total hip joint implant with an ipsilateral segmental femoral defect. Based on histological, radiological, laboratory, and clinical features, a diagnosis of concurrent chronic PJI and segmental femoral defect (Type IIIB, Paprosky classification) was made. After multidisciplinary team discussion, three-dimensional (3D)-printed, custom-made antibiotic spacers were created that could be used to mold antibiotic-loaded cement spacer. These were placed following PJI debridement in the first stage of revision surgery. After the PJI was eliminated, a 3D-printed, custom-made, femoral prosthesis was created to repair the considerable femoral defect. After 20-mo follow-up, the patient had excellent functional outcomes with a near-normal range of hip movement. So far, neither evidence of recurrent infection nor loosening of the prosthesis has been observed. CONCLUSIONWe describe a case of “two-stage, custom-made” total hip revision to treat PJI with a concurrent segmental femoral defect. Use of a personalized, 3D-printed spacer and proximal femoral prosthesis led to satisfactory hip function and no early postoperative complications. Use of a customized implant provides surgeons with an alternative option for patients where no suitable spacer or implant is available. However, the long-term function, longevity, and cost-effectiveness of the use of custom-made prostheses have yet to be fully explored.

Évolution et facteurs de risque de transfusion et d’accident thrombo-embolique après arthroplastie primaire et de révision de prothèses totales de hanche et de genou : analyse d’une base nationale sur 736061 cas

BackgroundOver the last years, new transfusion guidelines and pharmaceuticals have been introduced in primary and revision total hip and knee arthroplasty (P-THA, P-TKA, R-THA, R-TKA). In the US, a substantial decrease in transfusions has been observed in recent years. Little data exists on the subject in Europe. In this context we aimed to analyze: 1) Is there also a significant decrease in blood transfusion for these procedures in Germany? 2) Which patient and hospital related factors are associated with the risk of blood transfusion? 3) Is there a trend in complications, especially venous thromboembolism and stroke events that can be linked to tranexamic acid use? HypothesisThere is a significant trend in decreasing blood transfusions in hip and knee arthroplasty. MethodsUsing nationwide healthcare insurance data for inpatient hospital treatment, 736,061 cases treated between January 2011 and December 2017 were included (318,997 P-THAs, 43,780 R-THAs, 338,641 P-TKAs, 34,643 R-TKAs). Multivariable logistic regression was used to model the odds of transfusion as a function of the year of surgery. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated. ResultsIn each cohort the odds of transfusion decreased over time (2017 vs. 2011 (reference): P-THA: OR 0.42 (95%CI 0.39–0.45), P-TKA: OR 0.41 (95%CI 0.37–0.46), R-THA: OR 0.52 (95%CI 0.47–0.58), R-TKA: OR 0.53 (95%CI 0.46–0.61). Patient-related risk factors for blood transfusion included older age, female gender, lower Bodu Mass Index, comorbidities such as renal failure, cardiac arrhythmia, congestive heart failure, valvular disease, coagulopathy, depression, and antithrombotic medication prior to surgery. Venous thromboembolism or stroke events did not increase over the study period. DiscussionThe incidence of blood transfusions in primary and revision TKA and THA decreased over the study period. This may be due to new transfusion guidelines and the introduction of novel pharmaceuticals such as tranexamic acid. A further improved patient blood management and a focus on vulnerable patient groups might lead to a further future reduction of transfusions, especially in R-THA. Level of EvidenceIII; comparative observational Study.

Letter to the editor regarding “Outcomes of patients with unexpected diagnosis of infection at total hip or total knee arthroplasty revisions”

Letter to the editor regarding “Outcomes of patients with unexpected diagnosis of infection at total hip or total knee arthroplasty revisions”

Outcomes of patients with unexpected diagnosis of infection at total hip or total knee arthroplasty revisions.

The pre-operative differential diagnosis between periprosthetic joint infections (PJIs) and aseptic failure is challenging particularly in low virulence and biofilm-related infections. This study aimed to assess the incidence and survival of patients with unexpected PJIs in a presumed aseptic revision of total hip (THA) and knee (TKA) arthroplasties. A retrospective analysis of a prospective cohort of patients was performed with 295 patients undergoing THA (n = 241) or TKA (n = 54) revision for presumed aseptic causes. Patients were diagnosed with unexpected PJI taking into account leukocyte count in the synovial fluid, sonicate, synovial culture, and tissue cultures of samples collected during surgery. The primary endpoint was the infection-free implant survival rate at theoneyear follow-up. The unexpected PJIs were 60 out of 295 (20.3%), whereas 235 (79.7%) were aseptic revisions. In the unexpected PJI group, 6 (11.1%) patients underwent knee revision and 54 (22.4%) hip revision. At the oneyear follow-up, one patient (1.6%) in the unexpected PJI group and 3 (1.3%) in the aseptic group (p = 1.0) failed for infection. The infection-free implant survival rate at the oneyear follow-up was 98.3% (C.I. 95%, 94.9-99.9%) for the unexpected PJI group and 98.7% (C.I. 95%, 97.3-99.9%) (p = 0.82) for the aseptic group. The incidence of unexpected PJIs in a presumed aseptic revision of THAs and TKAs has been previously underestimated. The infection-free implant survival rate at the oneyear follow-up in patients with unexpected PJIs was not significantly lower compared with patients undergoing aseptic revision.

Utility of the ACS-NSQIP surgical risk calculator in predicting postoperative complications in patients undergoing oncologic proximal femoral replacement.

Proximal femur replacement (PFR) in the setting of tumor resection is associated with a high rate of postoperative complication. The online American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator is approved by the Center of Medicare and Medicaid services to estimate 30-day postoperative complications. This study was to determine if the ACS-NSQIP can predict postoperative complications following PFR. We reviewed 103 (61 male and 42 female) patients undergoing PFR using the Current Procedural Terminology (CPT) codes available in the calculator: 27125 (hemiarthroplasty), 27130 (total hip), 27132 (conversion to total hip), 27134 (revision total hip), 27137 (revision acetabulum), 27138 (revision femur), and 27365 (excision tumor hip). The predicted rates of complications were compared with the observed rates. Complications occurred in 54 (52%) of patients, with the predicted risk based on CPT codes: 27125 (21.5%); 27130 (7.8%); 27132 (16.6%), 27134 (17.8%), 27137 (14.4%), 274138 (22.7%), and 27365 (16.2%). The calculator was a poor predictor of complications (27125, area under the curve [AUC] 0.576); (27130, AUC 0.489); (27132, AUC 0.490); (27134, AUC 00.489); (27137, AUC 0.489); (27138, AUC 0.471); and (27365, AUC 0.538). Oncologic PFR is known for complications. The ACS-NSQIP does not adequately predict the incidence of complications, and therefore cannot reliably be used in their shared decision-making process preoperative.

A Retrospective Analysis Comparing Post-Operative Bleeding with Various Doses of Aspirin after Lower Extremity Joint Arthroplasty or Revision.

Previous studies have shown that aspirin is noninferior to other anticoagulation therapies in preventing postoperative venous thromboembolism following lower extremity arthroplasty or revision; however, its optimal dosing for this indication is less clear. This study aims to compare the odds of bleeding between different aspirin dosages following lower extremity joint arthroplasty or revision. This is a 3-year retrospective multi-center cohort study across the United States and its territories. This study included patients admitted for total hip or knee arthroplasty or revision and were treated with prophylactic aspirin. Patients were assigned to groups based on a total daily aspirin dose of 81, 162, 325, or 650 mg. Data were analyzed for postsurgical bleeding and thromboembolism events occurring during the initial admission and up to 40 days following surgery. Other exploratory variables included type of surgery, hip or knee arthroplasty, length of stay, and patient demographic data. Among 53,848 patients receiving aspirin, 3922 received a total daily dose of 81 mg, 19,341 received a total daily dose of 162 mg, 5256 received a total daily dose of 325 mg, and 25,329 received a total daily dose of 650 mg. Bleeding occurred in 466 (0.87%) patients and venous thromboembolism (VTE) in 209 patients (0.39%). The odds of bleeding were compared using logistic regression, with the 650-mg dose as the reference group. None were statistically significant for bleeding between all studied aspirin doses: 81 mg (OR 1.12, 95% CI 0.83-1.51, p = 0.451), 162 mg (OR 0.83, 95% CI 0.67-1.03, p = 0.097), and 325 mg (OR 0.83, 95% CI 0.59-1.13, p = 0.245). The odds of VTE were also not statistically significant: 81 mg (OR 0.71, 95% CI 0.40-1.17, p = 0.181), 162 mg (OR 0.75 95% CI 0.54-1.03, p = 0.072), and 325 mg (OR 1.00, 95% CI 0.64-1.53, p = 0.989). There were no significant differences in the odds of bleeding or venous thromboembolism among all studied aspirin dosages in patients receiving aspirin for thromboprophylaxis following lower extremity joint arthroplasty or revision.