Revision Total Knee Research Articles

Longitudinal rates, risk factors, and costs of superficial and deep incisional surgical-site infection (SSI) after primary and revision total knee arthroplasty: A US retrospective claims database analysis.

We evaluated longitudinal rates, risk factors, and costs of superficial and deep incisional surgical-site infection (SSI) 6 months after primary total knee arthroplasty (pTKA) and revision total knee arthroplasty (rTKA). Patients were identified from January 1, 2016 through March 31, 2018, in the IBM MarketScan administrative claims databases. Kaplan-Meier survival curves evaluated time to SSI over 6 months. Cox proportional hazard models evaluated SSI risk factors. Generalized linear models estimated SSI costs up to 12 months. Of the 26,097 pTKA patients analyzed (mean age, 61.6 years; SD, 9.2; 61.4% female; 60.4% commercial insurance), 0.65% (95% CI, 0.56%-0.75%) presented with a deep incisional SSI and 0.82% (95% CI, 0.71%-0.93%) with a superficial incisional SSI. Also, 3,663 patients who had rTKA (mean age, 60.9 years; SD, 10.1; 60.6% female; 53.0% commercial insurance), 10.44% (95% CI, 9.36%-11.51%) presented with a deep incisional SSI and 2.60% (95% CI, 2.07%-3.13%) presented with a superficial incisional SSI. Infections were associated with male sex and multiple patient comorbidities including chronic pulmonary disease, pulmonary circulatory disorders, fluid and electrolyte disorders, malnutrition, drug abuse, and depression. Adjusted average all-cause incremental commercial cost ranged from $14,298 to $29,176 and from $41,381 to 59,491 for superficial and deep incisional SSI, respectively. SSI occurred most frequently following rTKA and among patients with pulmonary comorbidities and depression. The incremental costs associated with SSI following TKA were substantial.

C-reactive protein/albumin and C-reactive protein/fibrinogen ratios for the diagnosis of periprosthetic joint infection in revision total joint arthroplasty.

Testing for systemic inflammation markers is considered a simpler method for diagnosing periprosthetic joint infection (PJI). Changes in the C-reactive protein/albumin ratio (CRP/Alb ratio) and C-reactive protein/fibrinogen ratio (CRP/Fib ratio) are associated with PJI. This study aimed to evaluate the application of CRP/Alb and CRP/Fib ratios as novel inflammation-based markers for the diagnosis of PJI. We retrospectively evaluated 445 patients who underwent total hip and knee revision arthroplasties between January 2010 and February 2021. Of these, 129 patients were also independently evaluated for PJI with coagulation-related comorbidities. The patients were divided into two groups: the aseptic revision (268 patients) and PJI revision groups (187 patients). Subsequently, we evaluated the diagnostic value of the CRP/Alb and CRP/Fib ratios compared to other inflammation-based diagnoses using the area under the curve (AUC) values. The AUC values of the CRP/Alb and CRP/Fib ratios were 0.880 and 0.872, respectively, suggesting similar diagnostic potentials for PJI. The CRP/Alb and CRP/Fib ratios were better than the erythrocyte sedimentation rate (ESR), Alb, and Fib, whose AUC values were 0.765, 0.352, and 0.730, respectively, for the diagnosis of PJI. The optimal cut-off for the CRP/Alb ratio was 0.13, with good sensitivity (85.0%) and specificity (78.4%). The optimal cut-off CRP/Fib ratio was 2.04, with good sensitivity (81.3%) and specificity (80.6%). Notably, the CRP/Alb and CRP/Fib ratios had the highest sensitivity, followed by four conventional inflammatory markers, namely, CRP, ESR, Alb, and Fib, which had sensitivities of 80.2%, 67.4%, 50.8%, and 54.0%, respectively. Similar findings were observed in patients with coagulation-related comorbidities. Both the CRP/Alb and CRP/Fib ratios were significantly higher in patients with PJI than in those with aseptic failure and showed better sensitivity and specificity for diagnosing PJI than classical inflammatory markers.

Porous metal block based on topology optimization to treat distal femoral bone defect in total knee revision

Metal block augmentations are common solutions in treating bone defects of total knee revision. However, the stress shielding and poor osteointegration resulted from metal block application could not be neglected in bone defects restoration. In this study, a novel porous metal block was designed with topology optimization to improve biomechanical performance. The biomechanical difference of the topologically optimized block, solid Ti6Al4V block, and porous Ti6Al4V block in treating bone defects of total knee revision was compared by finite element analysis. The inhomogeneous femoral model was created according to the computed tomography data. Combined with porous structures, minimum compliance topology optimization subjected to the volume fraction constraint was utilized for the redesign of the metal block. The region of interest was defined as a 10 mm area of the distal femur beneath the contacting surface. The biomechanical performance of daily motions was investigated. The von Mises stress, the strain energy density of the region of interest, and the von Mises stress of metal blocks were recorded. The results were analyzed in SPSS. In terms of the region of interest, the maximum von Mises stress of the topological optimized group increased obviously, and its average stress was significantly higher than that of the other groups (p < 0.05). Moreover, the topologically optimized block group had the highest maximum strain energy density of the three groups, and the lowest maximum stress of block was also found in this group. In this study, the stress shielding reduction and stress transfer capability were found obviously improved through topology optimization. Therefore, the topological optimized porous block is recommended in treating bone defects of total knee revision. Meanwhile, this study also provided a novel approach for mechanical optimization in block designing.

Correlation of clinical joint function with histopathological features of knee joint fibrosis

Objective: To investigate the correlation between the joint function and the histologic grading after total knee arthroplasty, to aid in the early diagnosis and prognostication of arthrofibrosis. Methods: A total of 29 patients including 22 females and 7 males were enrolled retrospectively from October 2015 to October 2020. These patients had a mean age of 63 years (range 41 to 79 years) and underwent total knee revision in Jishuitan Hospital due to joint contraction or loss of range of motion. Histologic assessment was carried out by utilizing immunohistochemistry (IHC) and the Masson staining to evaluate the fibrosis and inflammation of the samples. Results: By light microscopy, early stage arthrofibrosis showed massive proliferation of myofibroblasts and fibroblasts with SMA expression by IHC. In late stage arthrofibrosis, hyaline degeneration occured with extensive hyperplasia of fibrosis-related tissue. The arthrofibrosis samples appeared blue with Masson staining. Lymphocytes showed perivascular distribution. The arthrofibrosis tissue was mostly grade 3 (26 samples) in histologic assessment, moderate grade (25 samples) in ALVAL score, and grade 1 (23 samples) in lymphocyte grading. Fibrosis grading showed an overwhelming correlation with range of motion (ROM) of the joint. The ALVAL score was highly correlated with the WOMAC score. There was also a direct correlation between inflammatory cell infiltration and pain. The fibrosis grading joint with ALVAL score showed a good predictive value of joint function after joint replacement surgery. Conclusions: The histologic assessment score is closely correlated to the joint function with predictive values for the prognosis after joint replacement surgery.

Impact of Coronavirus Disease-2019 Protocols on Primary and Revision Total Knee Arthroplasty.

Background: Surgical site infection (SSI) after total knee arthroplasty (TKA) is associated with increased morbidity and healthcare expenditures. During the coronavirus disease-2019 (COVID-19) pandemic, our institution intensified hygiene standards, including greater glove, personal protective equipment (PPE), and mask use. We assessed the effect of these changes on SSI rates in primary total knee arthroplasty (pTKA) and revision total knee arthroplasty (rTKA). Patients and Methods: A retrospective review was performed identifying TKA from January 2019 to June 2021 at a single institution. Baseline characteristics and outcomes were compared before (January 2019 to February 2020) and during (May 2020 to June 2021) the COVID-19 pandemic when no restriction on operative services was in place and were further analyzed during the first (May 2020 to November 2020) and second (December 2020 to June 2021) periods after full operative services were restored. Results: A total of 3,398 pTKA (pre-pandemic: 1,943 [57.2%]; pandemic: 1,455 [42.8%]) and 454 rTKA (pre-pandemic: 229 [50.4%]; pandemic: 225 [49.6%]) were included. For primary cases, superficial and deep SSI rates were similar before and during COVID-19; however, for revision TKA, the incidence of all (-0.32%, p = 0.035) and superficial (-0.32%, p = 0.035) SSIs decreased during COVID-19. Primary TKA had longer operative times (p < 0.001) and shorter length of stay (LOS; p < 0.001) during COVID-19. Both pTKA (p < 0.001) and rTKA (p = 0.003) were discharged to skilled nursing facilities less frequently during COVID-19 as well. Conclusions: After our hospital implemented COVID-19-motivated hygienic protocols, superficial SSI rates decreased in rTKA but not in pTKA. During COVID-19, patients were less likely to be discharged to skilled nursing facilities, and pTKA operative times increased. Although these changes occurred during intensified hygiene protocols, further research is needed to determine how these factors contributed to the observed changes.

Prevention of Orthopedic Prosthetic Infections Using Evidence-Based Surgical Site Infection Care Bundles: A Narrative Review

Background: The number of primary/revision total joint replacements (TJR) are expected to increase substantially with an aging population and increasing prevalence of comorbid conditions. The 30-day re-admission rate, in all orthopedic specialties, is 5.4% (range, 4.8%-6.0%). A recent publication has documented that the surgical site infection (SSI) infection rate associated with revision total knee (rTKR, 15.6%) and revision total hip (rTHR, 8.6%) arthroplasties are four to seven times the rate of the primary procedures (2.1%-2.2%). These orthopedic infections prolong hospital stays, double re-admissions, and increase healthcare costs by a factor of 300%. Methods: A search of PubMed/MEDLINE, EMBASE and the Cochrane Library publications, which reported the infection risk after TKR and THR, was undertaken (January 1, 1995 to December 31, 2021). The search also included documentation of evidence-based practices that lead to improved post-operative outcomes. Results: The evidence-based approach to reducing the risk of SSI was grouped into pre-operative, peri-operative, and post-operative periods. Surgical care bundles have existed within other surgical disciplines for more than 20 years, although their use is relatively new in peri-operative orthopedic surgical care. Pre-admission chlorhexidine gluconate (CHG) showers/cleansing, staphylococcal decolonization, maintenance of normothermia, wound irrigation, antimicrobial suture wound closure, and post-operative wound care has been shown to improve clinical outcome in randomized controlled studies and meta-analyses. Conclusions: Evidence-based infection prevention care bundles have improved clinical outcomes in all surgical disciplines. The significant post-operative morbidity, mortality, and healthcare cost, associated with SSIs after TJR can be reduced by introduction of evidence-based pre-operative, intra-operative, and post-operative interventions.

Modular Augmentation in Varus-Valgus–Constrained Knee Arthroplasty—Do We Need Sleeves to Avoid Femoral Loosening After Excessive Distal Augmentation?

BackgroundIn revision total knee arthroplasty, zonal fixation methods with a combination of augments, press-fit stems, and sleeves are popular. We hypothesized that high distal femoral augmentation with diaphyseal press-fit stems leads to an increased rate of early aseptic loosening and that femoral metaphyseal sleeves improve implant survival. Therefore, we retrospectively investigated implant survival in relation to augment heights and sleeves. MethodsA total of 136 patients with mean clinical follow-up of 50 months (range, 28-85) who underwent modular total knee arthroplasty and revision total knee arthroplasty with semiconstrained implants between January 2012 and July 2018 were retrospectively evaluated. Implant survival with 4, 8, and 12 mm distal femoral augments was compared to no distal augmentation. Subsequently, a subgroup analysis was performed for femoral sleeve implantation. ResultsWe observed an implant survival rate of 97.0%, 87.5%, and 69.2% for 4, 8, and 12 mm distal femoral augmentation, respectively (P = .73; P = .19; P = .008). The implant survival rate with femoral sleeves was 95.8% for the 8 mm augments and 85.7% for the 12 mm augments (P = .42; P = .96). Without femoral sleeves, the implant survival rate was 78.3% with the 8 mm augments and 50.0% with the 12 mm augments (P = .02; P < .001). ConclusionHigher rates of aseptic femoral loosening were identified for distal femoral augmentation of 8 mm or more without metaphyseal sleeve fixation in semiconstrained implants. Thus, in cases with femoral metaphyseal bone damage requiring high distal femoral augmentation, metaphyseal sleeves should be used to avoid early aseptic femoral loosening.

Biomechanical Comparison Between Porous Ti6Al4V Block and Tumor Prosthesis UHMWPE Block for the Treatment of Distal Femur Bone Defects.

Purpose: The management of bone defects is a crucial content of total knee revision. This study compared the biomechanical performance of porous Ti6Al4V block and tumor prosthesis UHMWPE block in treating distal femoral bone defects. Methods: The finite element models of AORI type 3 distal femoral bone defect treated with porous Ti6Al4V block and UHMWPE block were established. Sensitivity analysis was performed to obtain the appropriate mesh size. The biomechanical performance of treatment methods in bone defects were evaluated according to the peak stress, the Von Mises stress distribution, and the average stresses of regions of interest under the condition of standing on one foot and flexion of the knee. Statistical analysis was conducted by independent samples t-test in SPSS (p < 0.05). Results: In the standing on one-foot state, the peak stress of the porous Ti6Al4V block was 12.42 MPa and that of the UHMWPE block was 19.97 MPa, which is close to its yield stress (21 MPa). Meanwhile, the stress distribution of the UHMWPE block was uneven. In the flexion state, the peak stress of the porous Ti6Al4V block was 16.28 MPa, while that of the UHMWPE block was 14.82 MPa. Compared with the porous Ti6Al4V block group, the average stress of the region of interest in UHMWPE block group was higher in the standing on one foot state and lower in the flexion state (p < 0.05). Conclusion: More uniform stress distribution was identified in the porous Ti6Al4V block application which could reserve more bone. On the contrary, uneven stress distribution and a larger high-stress concentration area were found in the UHMWPE block. Hence, the porous Ti6Al4V block is recommended for the treatment of AORI type 3 distal femoral bone defect.

The Cost-Effectiveness of Tibial Metaphyseal Cones in Revision Total Knee Arthroplasty.

The purpose of this study is to evaluate the cost-effectiveness of tibial cones in revision total knee arthroplasty. A Markov model was used for cost-effectiveness analysis. The average cone price was obtained from Orthopedic Network News. The average cone aseptic loosening rate was determined by literature review. Hospitalization costs and baseline re-revision rates were calculated using the PearlDiver Database. The maximum cost-effective cone price varied from $3514 at age 40 to $648 at age 90, compared to the current average selling price of $4201. Cones became cost-effective with baseline aseptic loosening rates of 0.89% annually at age 40 to 4.38% annually at age 90, compared to the current average baseline loosening rate of 0.76% annually. For the average patient, tibial cones are not cost-effective, but may become so at lower prices, in younger patients, or in patients at substantially increased risk of aseptic loosening.

Unsuspected Positive Cultures in Planned Aseptic Revision Knee or Hip Arthroplasty-Risk Factors and Impact on Survivorship.

Unsuspected positive cultures (UPCs) may be found at the time of planned aseptic revision surgery and have previously been associated with decreased implant survival. However, reported rates vary greatly, and potential risk factors are widely unknown. This study investigates the rate of UPCs, implant survival, as well as potential risk factors for UPCs and revision. This is a retrospective, single-center study on 434 cases of total hip arthroplasty (THA 277) and knee revision arthroplasty (TKA 157) performed between 2010 and 2017. Microbiology culture results, revision-free survival (RFS) and infection-free (IFS) survival, and the potential impact of UPCs as well as patient- or procedure-related risk factors were investigated at a minimum follow-up of 24 months (median 41 months). A total of 37% of patients had a positive culture (160/434). 27% (119/434) had a solitary positive culture, and 9% (41/434) had ≥2 positive cultures of the same species. Most commonly, coagulase-negative staphylococci were cultured. Overall, 32% (13/41) of patients with ≥2 positive cultures underwent revision for infection compared with 6% (17/274) of patients with negative cultures. RFS and IFS were reduced if ≥2 cultures were positive. Single positive cultures had no impact on RFS or IFS. Male sex, elevated serum C-reactive protein, and obesity were independently associated with finding ≥2 UPCs in revision THA. Appearance of ≥2 UPCs in aseptic revision leads to reduced RFS and IFS. Males, obese patients, and patients with elevated serum C-reactive protein planned for THA revision should be considered for extended diagnostics to rule out periprosthetic joint infection.

Comparison of Operating Room Air Quality in Primary Versus Revision Total Knee Arthroplasty.

Airborne biologic particles (ABPs) can be measured intraoperatively to evaluate operating room (OR) sterility. Particulate matter (PM) up to 2.5 microns can contain microbial species which may increase infection risk. Our study examines the differences in air quality and ABP count in primary total knee arthroplasty (TKA) and revision TKA (rTKA). We analyzed primary and rTKAs in a single OR at an academic institution from January 2020 to December 2020. Procedures from March 15, 2020, to May 4, 2020, were excluded to avoid COVID-related confounding. Temperature, humidity, and ABP count per minute were recorded with a particle counter intraoperatively and cross-referenced with surgical data from the electronic health records using procedure start and end times. Descriptive statistics were used to evaluate the differences in variables. P values were calculated using t-test and chi-square test. A total of 107 TKA cases were included: 79 (73.8%) primary TKAs and 28 (26.2%) rTKAs. Time spent in an OR was significantly higher for rTKAs (primary: 176 ± 46.7minutes vs revision: 220 ± 47.1 minutes, P < .0001). Compared to primary TKAs, rTKAs had significant percent increases in ABP rates for particles measuring 0.3 μm (+70.4%, P < .001), 0.5 μm (+97.2%, P < .0001), 1.0 μm (+53.2%, P= .001), and 2.5 μm (+30.3%, P= .017) and for PM 2.5 (+108.3%, P < .001) and PM 5.0 (+105.6%, P < .001). rTKAs had significantly longer time spent in an OR and significant percent increases in ABP rates for particles measuring 0.3 μm, 0.5 μm, and 1.0 μm compared to primary TKAs. Measurements of PM 2.5 and 5.0 (which can contain large numbers of microbes) were also significantly greater in rTKAs. Further research is needed to determine whether the size and quantity of ABPs translate to higher infection rates after rTKA.

Summary of outcomes of a non-invasive biomechanical therapy for patients with knee osteoarthritis

Osteoarthritis (OA) is the second most frequent chronic musculoskeletal (MSK) condition after low back pain and a leading cause of disability in the elderly. The number of people living with disability will continue to rise with the aging of the population. Moreover, the rapid increase in rates of surgical intervention, i.e. Total knee replacement (TKR) and revision TKRs, is expected to place an immense burden on the health care system and society. There is a call for better rehabilitation, new interventions, and disease management for patients with knee OA. The purpose of this article is to review the biomechanics of knee OA and biomechanical interventions and to summarize the current literature on a non-invasive, home-based biomechanical treatment for patients with knee OA. The evidence suggests an improvement in symptoms and biomechanical indicators after using the home-based biomechanical intervention. In the presence of value-based payment to improve efficiency and effectiveness in delivering medical care, these results are promising.

Porous Metal Block Based on Topology Optimization to Treat Distal Femoral Bone Defect in Total Knee Revision

Porous Metal Block Based on Topology Optimization to Treat Distal Femoral Bone Defect in Total Knee Revision

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.

The application of close incisional negative pressure wound therapy in revision arthroplasty among asian patients: a comparative study

IntroductionPeri-prosthetic joint infection (PJI) was one of the main causes of revision of arthroplasty. In order to reduce wound complications and surgical site infections, close incisional negative pressure wound therapy (ciNPWT) has been introduced into arthroplasty. This study was designed to review the clinical benefits of the application of ciNPWT in revision arthroplasty.MethodsThis was a single-centre retrospective comparative study approved by the Institutional Review Board. Patients, who underwent revision total knee arthroplasty or revision total hip arthroplasty at the author’s institution from January 2016 to October 2019, were included in this study. The ciNPWT cohort included all eligible patients, who underwent operations from January 2018 to October 2019, with the use of ciNPWT(n = 36). The control cohort included all eligible patients, who underwent operations from January 2016 to December 2017 with the use of conventional dressing(n = 48). The incidences of wound complications were compared to both cohorts.ResultsThere was a statistically significant difference in the rate of superficial surgical site infection (SSI) between control cohort and ciNPWT cohort (12.5% in control vs 0% in ciNPWT, p = 0.035). However, there was no statistically significance of the overall wound complication rate for both cohorts. (14.6% in control vs 8.3% in ciNPWT, p = 0.504).ConclusionsThe application of ciNPWT could result in a lower rate of superficial surgical site infection when compared with conventional dressing among the patients undergoing revision total knee and total hip arthroplasties.Trial registrationUW19-706

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.

The Proximal Placement of the Knee Joint in the 1-Stage Treatment of Infected Knee Revisions With Large Anterior Soft Tissue Defects

Introduction: No good mechanisms are available for reconstruction of large anterior soft tissue defects associated with infected total knees [periprosthetic joint infections of the knee (PJI-K)]. Patellectomy is usually required due to involvement with adjacent large anterior soft tissue defects left after radical debridement, free flaps are required for closure. This type of flap necessitates the use of a drop lock brace in ambulation. Our question is whether the proximal placement of the knee joint with longer tibial segments can reduce the number of free flaps and reduce the need for a drop lock brace by reattaching the quadriceps directly to the hinged tibial component. Methods: We retrospectively analyzed 35 cases with a minimum 2-year follow-up. Of 1-stage total knee revisions for PJI-K with the proximal placement of the knee joint for large anterior soft tissue defects left after debridement. Results: The average knee joint displacement was 85 mm. Eleven recurred with infection and 4 required amputation. Eighteen had enough extensor power to walk with a cane or walker as opposed to requiring a drop lock brace. Fifteen patients did not need any free or local flaps, rather these patients only required adjacent soft tissue transfer during surgery. Discussion: This novel proximal placement of the knee joint in patients with PJI-K who have large anterior soft tissue defects lessens the need for free flaps. The proximal placement also allows for reconstruction of what is left of the quadriceps mechanism into the tibial component and usually provides enough extensor power to lock the hinge joint.

Both younger and elderly patients in pain are willing to undergo knee replacement despite the COVID-19 pandemic: a study on surgical waiting lists.

PurposeTo identify factors influencing patient’s availability to re-schedule primary total knee replacement (TKR) or revision (RKR) surgery after the lockdown (March–May 2020) during the COVID-19 pandemic.MethodsA prospective cohort study through a telephone survey was performed in 156 patients (143 for primary and 13 for revision) included in the TKR and RKR surgical waiting list before March 2020. Contact of each patient with COVID-19, stress and anxiety, perceived pain, and function were obtained in the interviews, and also the preference of each patient to have re-scheduled surgery (early or late). Finally, we registered their response (acceptance or refusal) when surgery was effectively re-scheduled.Results88 out of 156 patients waiting for knee replacement (76/143 of those waiting for TKR, 12/13 of those waiting for RKR) declared themselves ready for surgery in less than 1 month. When re-scheduled, 115 patients underwent surgery and 41 refused. Significantly different preferences were found for age (more prone to surgery if under 65), revision surgery (more readily available), pain (7.9 ± 1.7/10 in NRS in those undergoing surgery, 5.6 ± 2.3/10 in those refusing, p = 0.000), or COVID-19 diagnosis, but not other close contact with COVID-19, comorbidities, stress, or anxiety. A logistic regression model confirmed that revision surgery (OR 9.33), perceived severe pain (OR 5.21), and age under 65 years (OR 5.82) were significantly associated with patient preference. The probability of patients over 65 to prefer early surgery reached 60% only with pain at or above 9/10.ConclusionsSurgical timing preferences for knee replacement vary between patients older than 65 years (immediate surgery only when pain is intense) and younger patients (immediate surgery no matter the amount of pain). Even if COVID-19 severely stroke our population, the need for knee replacement stood in the young population and even in the aged population at risk for COVID when pain was important.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00167-021-06611-x.

Les pertes sanguines sont 1,38 à 2,17 fois plus importantes après reprise de PTG qu’après PTG primaire : analyse rétrospective de 898 cas

BackgroundThere are a number of factors that influence blood loss during and after primary total knee arthroplasty (TKA) and revision TKA (rTKA). The purpose of this study was to provide a factorial assessment that would aid surgeons in managing expected blood loss in rTKA, when compared to TKA. The first question asked was the blood loss and transfusions between TKA and rTKA and the second question were risk factors for blood loss after rTKA. HypothesisBlood loss in any rTKA is higher than in TKA by a factor of 2. Patients and methodsA retrospective single-center consecutive series of rTKA between 2006 and 2018 was performed. Based on the rTKA types identified in joint registries, 4 rTKA cohorts were created: aseptic minor rTKA, aseptic major rTKA, 1st stage, and 2nd stage septic rTKA. A consecutive TKA cohort from the same study period was used to create a propensity score matched cohort with the aseptic major rTKA cohort. ResultA total of 622 rTKA were identified. Aseptic major rTKA had double the median blood loss than TKA. The lowest blood loss was observed in the TKA group followed by aseptic minor rTKA, and the highest in 2nd stage septic rTKA. The median total blood loss was higher in all rTKA by a factor ranging between 1.38 and 2.17. Higher age, female gender, lower preoperative hemoglobin, chronic heart disease and history of myocardial infarction were risk factors for increased blood loss. The type of rTKA performed was not predictive of blood loss in the linear regression analysis. DiscussionBlood loss after rTKA is 1.38- to 2.17-fold higher than after TKA. The blood loss observed in 2nd stage septic rTKA and aseptic major rTKA was the highest. Older, female patients, with a low preoperative hemoglobin were identified to be at the highest risk of blood loss after rTKA. Strategies for further blood loss reductions need to be utilized to the fullest extent for these procedures. Level of evidenceIII; retrospective prognostic study.