The impact of prior ACL reconstruction on total knee arthroplasty outcomes: a retrospective matched cohort study.

INTRODUCTION: Discrepant data exists regarding the outcomes following total knee arthroplasty (TKA) with a prior anterior cruciate reconstruction (ACLR). The purpose of our study was to compare surgical and medical outcomes in the patients with prior ACLR undergoing TKAs compared to a matched control group of the patients who had undergone TKAs without prior ACLR. We hypothesized that the patients with prior ACLR would have inferior clinical outcomes. MATERIAL/METHODS: We retrospectively queried the PearlDiver-database for patients who underwent TKA following ACLR from 2011 to 2020. We used propensity-score matching to create two cohorts. The two-sided independent t-test and Chi-Squared test were used. RESULTS: We identified 2,174 patients who had prior ACLR before the TKAs. There were another 1,348,870 patients who did not have ACLR before the TKAs. After matching, each group had 2,171 patients. The ACLR-TKA group had significantly lower rates of aseptic revision at 2 years (1.2% vs. 4.0%, OR 0.3, p < 0.01), PJI requiring antibiotic spacer at 2 years (0.3% vs. 0.8%, OR 0.35, p = 0.02), and MUA at 90 days (0.4% vs. 7.5%, OR 0.05, p < 0.01). The rate of wound disruption was lower for the ACLR-TKA group at 90 days (p = 0.03) as were several medical complications including AKI at 90 days (p < 0.01), DVT at 90 days (p < 0.01), pneumonia at 90 days (0.04), and required blood transfusion at 90 days (p < 0.01). CONCLUSION: These results differed from our expectations. Within the limitations of the study, we are unable to determine the factors for the lower complications in the ACLR-TKA group. The data from this study are different from what had been reported in the previous studies.

Total Hip Arthroplasty in Nonagenarians - A National In-Patient Sample-Based Study of Perioperative Complications.

Background: Nonagenarians are a rapidly expanding population in the United States. These patients are met with increasing rates of hip arthritis, necessitating the need for total hip arthroplasty (THA). However, there is currently limited information on hospitalization information and perioperative complications in this population. Methods: In this retrospective study, we used the Nationwide Inpatient Sample (NIS) database from 2016-2019 to analyze the incidence of perioperative complications, length of stay (LOS), and the cost of care (COC) among patients undergoing THAs who were categorized as nonagenarians, and those who were not. Results: The NIS database identified 309 100 patients who underwent THAs from 2016-2019. Of those, 1864 patients (.6%) were nonagenarian, while the remaining 307 236 patients were included under the non-nonagenarian category (control). The mean age in the nonagenarian group was 90 years compared to the control group which had a mean age of 65.8 years. There was an increased incidence of mortality rate (nonagenarian group .2%, control group .03%, P < .001), myocardial infarction (MI) (nonagenarian group .1%, control group .02%, P = .01), acute renal failure (ARF) (nonagenarian group 5.4%, control group 1.6%, P < .001), blood anemia post-operatively (nonagenarian group 28.9%, control group 17.2%, P < .001), and deep vein thrombosis (DVT) (nonagenarian group .48%, control group .07%, P < .001) in the nonagenarian group. The COC for the nonagenarian group was higher than that in the control group (P < .001). The mean LOS was longer in the nonagenarian group (3.1 days) in comparison to the control group (1.96 days) (P < .001). Conclusions: Nonagenarians had significantly higher rates of both orthopedics and medical complications than the younger patients undergoing THAs. In addition, the nonagenarian group incurred higher COC. This information is useful for the providers to make informed decisions regarding patient care and resource utilization for nonagenarian patients undergoing THAs.

Complications of primary total hip arthroplasty in human immunodeficiency virus-positive patients with femoral head osteonecrosis.

BACKGROUND: Femoral head osteonecrosis (FHON) is a well-recognised complication in patients with human immunodeficiency virus (HIV) infection. Total hip arthroplasty (THA) is a reliable solution to FHON and has provided functional improvement and pain relief in these patients. Higher complication rates, in particular infections, have been reported in the series of THAs done in the HIV-positive patients. The purpose of this study was to evaluate the complication rate of THA for FHON in HIV-positive patients managed with the highly active antiretroviral therapy (HAART) protocols. METHODS: A retrospective review was performed of HIV-positive patients with FHON who underwent THAs over a 10-year period at a single institution. RESULTS: A total of 56 THAs (44 patients) met the inclusion criteria. The mean age at the time of THAs was 47 (range 34-60) years. Of the 44 patients, 39 (88.6%) were males. The mean follow-up was 6.6 (range 2.0-11.3) years. The overall complication rate was 12.5%, with 2 (3.6%) cases of deep periprosthetic infections. CONCLUSIONS: HIV-positive patients with FHON undergoing THAs do have a considerable complication rate (12.5%). The deep periprosthetic infection rate (3.6%) in these patients, however, has decreased with contemporary disease modification protocols.

Standardized total knee arthroplasty pathway improves outcomes in minority patients.

OBJECTIVES: Inferior total knee arthroplasty (TKA) outcomes are reported in minority populations. Standardized TKA pathways improve outcomes but have not been studied extensively in minority populations. This study evaluated the impact of TKA pathway standardization at an urban teaching hospital that predominantly treats minority patients. STUDY DESIGN: Retrospective cohort study. METHODS: This study compared primary TKA outcomes before and after implementation of a standardized multidisciplinary pathway that emphasized preoperative education and discharge planning, preemptive multimodal pain control, and early rehabilitation. Patients were grouped as "nonpathway" (n = 144) or "pathway" (n = 182) based on whether they underwent TKA before or after pathway implementation. Outcomes included length of stay (LOS), patient-controlled analgesia (PCA) use, blood transfusion, postoperative hemoglobin, complications, and discharge disposition. Analysis involved negative binomial and multiple logistic regression models, t tests, and Fisher's exact tests. RESULTS: Mean (SD) age was 61.6 (8.7) years, and 36.5% were men. Ethnicity of the patients included Hispanic (44.5%), African American (27.9%), Asian (14.1%), and White (12.9%). Pathway and nonpathway patients were similar demographically and racially. Pathway patients had shorter LOS (P = .04), less PCA use (P < .001), more frequent discharge home (P = .03), fewer transfusions (P = .002), and higher postoperative hemoglobin (P < .001). Overall incidence of complications was similar (P = .61). Nonpathway patients developed more cardiopulmonary complications (P = .02), whereas pathway patients had more wound dehiscence (P = .01). CONCLUSIONS: Compared with nonpathway patients, standardized TKA pathway patients had shorter LOS, decreased PCA use, increased discharge to home, fewer blood transfusions, and higher postoperative hemoglobin, with no difference in total incidence of complication.

Sources of contamination in the operating room: A fluorescent particle powder study.

This study utilized fluorescent particle powder to investigate 2 potential sources of sterile field contamination in the operating room (OR): forced-air warming blankets and OR light manipulation. In part 1, sterile draping for knee replacement surgery was performed on a mannequin in a sterile OR, comparing field contamination with the forced-air warming on versus off during draping. In part 2, OR lights coated with fluorescent powder were manipulated over a sterile field. Proper operation of these devices may reduce the particle burden on the surgical field.

Venous Thromboembolism Prophylaxis after Total Knee Arthroplasty.

Venous thromboembolic disease (VTED) is a major cause of morbidity and mortality after total knee arthroplasty (TKA). Current VTED prophylaxis protocols consist of early mobilization, mechanical compression devices, and pharmacologic agents. Venous phasic flow-regulated below-knee devices are generally favored, but the optimal duration and method of mechanical prophylaxis is unknown. Risk stratification models have been developed to guide pharmacologic prophylaxis. For patients with standard VTED risk profile, aspirin has become increasingly popular. Recent studies have validated the efficacy, relatively low bleeding risks, and cost-effectiveness of aspirin in the patients with standard risk profile. Current evidence suggests that the newer oral anticoagulants, including the factor Xa and the direct thrombin inhibitors, are effective for the reduction of postoperative VTED but may be associated with increased bleeding and wound complication rates.

Stem geometry changes initial femoral fixation stability of a revised press-fit hip prosthesis: A finite element study.

BACKGROUND: Stable femoral fixation during uncemented total hip arthroplasty is critical to allow for subsequent osseointegration of the prosthesis. Varying stem designs provide surgeons with multiple options to gain femoral fixation. OBJECTIVE: The purpose of this study was to compare the initial fixation stability of cylindrical and tapered stem implants using two different underreaming techniques (press-fit conditions) for revision total hip arthroplasty (THA). METHODS: A finite element femur model was created from three-dimensional computed tomography images simulating a trabecular bone defect commonly observed in revision THA. Two 18-mm generic femoral hip implants were modeled using the same geometry, differing only in that one had a cylindrical stem and the other had a 2 degree tapered stem. Surgery was simulated using a 0.05-mm and 0.01-mm press-fit and tested with a physiologically relevant loading protocol. RESULTS: Mean contact pressure was influenced more by the surgical technique than by the stem geometry. The 0.05-mm press-fit condition resulted in the highest contact pressures for both the cylindrical (27.35 MPa) and tapered (20.99 MPa) stems. Changing the press-fit to 0.01-mm greatly decreased the contact pressure by 79.8% and 78.5% for the cylindrical (5.53 MPa) and tapered (4.52 MPa) models, respectively. The cylindrical stem geometry consistently showed less relative micromotion at all the cross-sections sampled as compared to the tapered stem regardless of press-fit condition. CONCLUSIONS: This finite element analysis study demonstrates that tapered stem results in lower average contact pressure and greater micromotion at the implant-bone interface than a cylindrical stem geometry. More studies are needed to establish how these different stem geometries perform in such non-ideal conditions encountered in revision THA cases where less bone stock is available.

Tapered vs Cylindrical Stem Fixation in a Model of Femoral Bone Deficiency in Revision Total Hip Arthroplasty.

BACKGROUND: Distal fixation achieved with a tapered stem design has demonstrated favorable clinical results in revision total hip arthroplasty in the setting of severe bone defects. However, stem subsidence is common with this stem design. PURPOSE: The purpose of this study is to compare the initial fixation stability of a tapered stem design to a fully porous-coated cylindrical stem design in a model of severe femoral bone deficiency. METHODS: Tapered and cylindrical stems (n = 8) were implanted into a model femur with progressively shorter segments for fixation (9, 6, or 3 cm). The stems were axially loaded, and the force to produce subsidence was recorded. RESULTS: Average loads to produce 150 µm of displacement with a 3-cm segment were higher for the tapered stem (393 N vs 221 N, P < .01). No difference was observed in the 6- or 9-cm models. Average loads to produce failure (>4-mm subsidence) were also higher for tapered stems with a 3-cm segment (1574 N vs 500 N, P < .0001). A regression analysis determined the minimum segment length of 1.5-2.5 cm to obtain stable fixation with a tapered stem design (R(2) = 0.78, P < .001). CONCLUSIONS: Tapered stems required higher loads to produce subsidence than cylindrical stems in a revision THA model. Revision tapered stems require a minimum intact segment of 1.5-2.5 cm to obtain adequate initial fixation stability. Revision tapered stems have superior initial fixation stability to cylindrical stems in the setting of severe bone loss.

Preoperative flexion does not influence postoperative flexion after rotating-platform total knee arthroplasty.

PURPOSE: Preoperative range of motion (ROM) has been regarded as one of the most important factors in predicting postoperative ROM following total knee arthroplasty (TKA). Mobile-bearing TKA designs have been suggested to possibly improve the knee kinematics compared to fixed-bearing designs. The purpose of this study was to examine the difference in postoperative flexion as a function of preoperative flexion in a consecutive series of TKAs done using a posterior-stabilized rotating-platform prosthesis. METHODS: ROM was assessed in 153 consecutive TKAs done using a rotating-platform posterior cruciate-substituting design. Patients were divided into two groups based on their preoperative ROM (Group 1 < 95°, Group 2 > 95°). The Knee Society Score (KSS) and ROM were assessed preoperatively, 3 months and 12 months postoperatively. RESULTS: There was no difference in flexion 12 months after surgery between groups (mean 120° and 123°, respectively. n.s.). After 3 month follow-up, no increase in ROM was experienced by either group. Patients in Group 1 experienced significantly greater increases in both ROM (p < 0.001) and KSS (p < 0.05). There was no difference in the KSS at 12 months after surgery between groups. CONCLUSION: In this series of patients undergoing TKA with a rotating-platform prosthesis, the preoperative ROM was not predictive of the postoperative ROM. Patients with stiff knees preoperatively may benefit from a mobile-bearing design prosthesis.

New anticoagulants for thromboprophylaxis after total knee arthroplasty.

Total knee arthroplasty (TKA) is one of the most common orthopedic procedures in the United States. The number of TKAs is expected to rise significantly over the next 2 decades. One of the most common complications after TKA is venous thromboembolism (VTE), which is potentially fatal. The incidence of VTE is effectively reduced by prophylactic anticoagulants, and clinical guidelines have been developed to improve VTE management. However, current anticoagulants have limitations in terms of efficacy, safety, half-life, ease of administration, and patient adherence. Moreover, these anticoagulants require routine monitoring and dose adjustment, and potential bleeding complications represent an important concern. A new generation of anticoagulants, including recently approved rivaroxaban, is being developed to address the shortcomings of current agents. The efficacy and safety of these newer agents are comparable with those of existing ones. Rivaroxaban is the only new oral agent that is approved for use in TKA and that has demonstrated an efficacy superior to that of enoxaparin in phase 3 trials. To optimize the management of VTE prophylaxis after TKAs, orthopedic surgeons must have a thorough understanding of these new oral agents.

Apixaban and rivaroxaban decrease deep venous thrombosis but not other complications after total hip and total knee arthroplasty.

Apixaban and rivaroxaban are oral direct factor Xa (FXa) inhibitors used for VTE prevention after total hip (THA) and total knee arthroplasty (TKA). A meta-analysis of level I studies comparing rivaroxaban 10 mg daily or apixaban 2.5 mg twice daily to enoxaparin for the prevention of VTE after THA or TKA was performed analyzing efficacy and safety outcomes. Seven studies met the inclusion criteria including 24,385 patients. Oral FXa inhibitors were superior to enoxaparin in preventing DVT (p<0.00001). There was no difference in the rate of PE, death, major bleeding, blood transfusion requirement, reoperation for bleeding or postoperative wound infections. Oral FXa inhibitors are superior to enoxaparin in preventing DVT after THA and TKA. There is no difference in the rate of PE, death, or postoperative wound complications.

The efficacy and safety of rivaroxaban for venous thromboembolism prophylaxis after total hip and total knee arthroplasty.

Venous thromboembolism (VTE) is a common complication after total hip and total knee arthroplasty. Currently used methods of VTE prophylaxis after these procedures have important limitations, including parenteral administration, and unpredictable plasma levels requiring frequent monitoring and dose adjustment leading to decreased patient compliance with recommended guidelines. New oral anticoagulants have been demonstrated in clinical trials to be equally efficacious to enoxaparin and allow for fixed dosing without the need for monitoring. Rivaroxaban is one of the new oral anticoagulants and is a direct factor Xa inhibitor that has demonstrated superior efficacy to that of enoxaparin. However, the data also suggest that rivaroxaban has an increased risk of bleeding compared to enoxaparin. This paper reviews the available data on the efficacy and safety of rivaroxaban for VTE prophylaxis after total hip and total knee arthroplasty.

Thromboembolic prophylaxis in orthopedic surgery using dabigatran: an oral direct thrombin inhibitor.

Dabigatran etexilate is a direct thrombin inhibitor that has been in clinical use for the prevention and treatment of venous and arterial thrombosis. Dabigatran allows for oral administration, has a rapid onset of action and has a predictable anticoagulant effect. Studies in healthy volunteers and in patients undergoing orthopedic surgery indicate that dabigatran has a predictable pharmacokinetic profile, allowing for a fixed-dose regimen without the need for coagulation monitoring. Dabigatran is approved in the EU and Canada for prophylaxis of thromboembolism in patients undergoing total hip and knee arthroplasties. The focus of this article is on the clinical data of using dabigatran as venous thromboprophylaxis in orthopedic surgery patients.

Total hip arthroplasty in the ankylosed hip.

Altered biomechanics secondary to hip ankylosis often result in degeneration of the lumbar spine, ipsilateral knee, and contralateral hip and knee. Symptoms in these joints may be reduced with conversion total hip arthroplasty (THA) of the ankylosed hip. THA in the ankylosed hip is a technically challenging procedure, and the overall clinical outcome is generally less satisfactory than routine THA performed for osteoarthritis and other etiologies. Functional integrity of the hip abductor muscles is the most important predictor of walking ability following conversion THA. Many patients experience persistent limp, and it can take up to 2 years to fully assess final functional outcome. Risk factors cited for increased risk of failed THA include prior surgical ankylosis and age <50 years at the time of conversion THA.

New oral anticoagulants in venous thromboembolism prophylaxis in orthopaedic patients: are they really better?

Prophylaxis against venous thromboembolism (VTE) is considered standard of care. Appropriate chemoprophylaxis for VTE has been mandated by the United States government agencies and consumer groups. However, controversies exist regarding the most clinically relevant and safe chemoprophylaxis protocols in patients undergoing joint replacement surgery. Thus, this paper reviews the clinical efficacy and safety of newer oral anticoagulants. A literature search was performed for oral anticoagulants in advanced stages of development using PubMed and abstracts from thrombosis meetings. Most clinical trial data have demonstrated equal or superior efficacy in venographic endpoints in comparison to low-molecular-weight heparins (LMWH). However, bleeding complications have been reported to occur with oral anticoagulants as frequently as or more frequently than with LMWH. Other potential complications reported include liver enzyme elevation and cardiac irregularities. It remains to be established whether newer oral anticoagulants will be better alternatives to the current standard-of-care in real-life medical clinical practice.

Oral dabigatran versus enoxaparin for thromboprophylaxis after primary total hip arthroplasty (RE-NOVATE II*). A randomised, double-blind, non-inferiority trial.

This trial compared the efficacy and safety of oral dabigatran, a direct thrombin inhibitor, versus subcutaneous enoxaparin for extended thromboprophylaxis in patients undergoing total hip arthroplasty. A total of 2,055 patients were randomised to 28-35 days treatment with oral dabigatran, 220 mg once-daily, starting with a half-dose 1-4 hours after surgery, or subcutaneous enoxaparin 40 mg once-daily, starting the evening before surgery. The primary efficacy outcome was a composite of total venous thromboembolism [VTE] (venographic or symptomatic) and death from all-causes. The main secondary composite outcome was major VTE (proximal deep-vein thrombosis or non-fatal pulmonary embolism) plus VTE-related death. The main safety outcome was major bleeding. In total, 2,013 were treated, of whom 1,577 operated patients were included in the primary efficacy analysis. The primary efficacy outcome occurred in 7.7% of the dabigatran group versus 8.8% of the enoxaparin group, risk difference (RD) -1.1% (95%CI -3.8 to 1.6%); p<0.0001 for the pre-specified non-inferiority margin. Major VTE plus VTE-related death occurred in 2.2% of the dabigatran group versus 4.2% of the enoxaparin group, RD -1.9% (-3.6% to -0.2%); p=0.03. Major bleeding occurred in 1.4% of the dabigatran group and 0.9% of the enoxaparin group (p=0.40). The incidence of adverse events, including liver enzyme elevations and cardiac events, during treatment was similar between the groups. Extended prophylaxis with oral dabigatran 220 mg once-daily was as effective as subcutaneous enoxaparin 40 mg once-daily in reducing the risk of VTE after total hip arthroplasty, and superior to enoxaparin for reducing the risk of major VTE. The risk of bleeding and safety profiles were similar.

The eighth American college of chest physicians guidelines on venous thromboembolism prevention: implications for hospital prophylaxis strategies.

Venous thromboembolism (VTE) is the most common potentially preventable form of hospital-related mortality. It presents as a major healthcare burden, affecting both medical and surgical patients. The prevention of VTE has been identified as one of the most important in-hospital safety practices in the US. VTE guideline recommendations provide a framework for clinical practice and guide VTE prophylaxis policies. Guidelines produced by the American College of Chest Physicians (ACCP) are considered to be the 'gold standard' in VTE prevention, diagnosis and management, and have been updated. A number of differences exist between the new 2008 ACCP guidelines on VTE prevention and the previous version published in 2004. There are variations regarding VTE prevention, including new and stronger evidence-based recommendations for several indications and agents. The updated guidelines give a strong recommendation that every hospital develop a VTE prevention policy, which is particularly important given the current international drive to reduce the incidence of VTE. A formal hospital policy should help improve compliance with appropriate VTE prophylaxis strategies. The ACCP guidelines form a basis for improving patient safety at a time of public reporting of quality of care, hospital accreditation, national standards of care, and pay for performance initiatives. In this review, changes in recommendations for VTE prevention in the 2008 ACCP guidelines compared with the previous edition in 2004 are outlined. In addition, outstanding areas of debate are discussed and the role of the 2008 ACCP guidelines in the context of the new VTE performance measures analyzed.