Maintenance of Surgical Optimization in Total Joint Arthroplasty Patients.

BACKGROUND: There are increased efforts to maximize medical optimization to improve the outcomes of total joint arthroplasty (TJA). However, there is a paucity of literature demonstrating that optimized parameters are maintained throughout the perioperative period. METHODS: A retrospective review of 877 elective TJA patients from 2015 to 2019 was conducted. Patients who underwent medical optimization for body mass index (BMI), hemoglobin A1c (HbA1c), hemoglobin, albumin, and smoking status were reviewed at the initial visit, preoperatively, time of surgery, and one year postoperatively. For each of these variables at each time point, patients were stratified into 3 optimization groups. Analyses were performed to identify mean time to optimization, loss of optimization, and maintenance of optimization. RESULTS: Patients considered not optimized due to specific parameters at the initial visit were as follows: BMI (19%), HbA1c (13.5%), hemoglobin (16%), albumin (19%), and smoking status (9.5%). The mean time to optimization was 187.7 days [longest being BMI (220.1 days), and the shortest being HbA1c (60.9 days) (P = .0003)]. Patients who had intermediate optimization of BMI at the preoperative visit were at higher risk [odds ratio: 2.1 (0.97 to 4.6)] of worsening BMI by time of surgery (P < .0001). Between the preoperative and surgery time points, over 93.5% of patients maintained or improved optimization. CONCLUSIONS: Surgeon led medical optimization efforts alongside a TJA program provide maintenance of, or improvement in optimization in more than half of TJA patients up to one year postoperatively. Patients who had a BMI between 40 and 45 at the preoperative visit are at significant risk of increasing their BMI by the day of surgery.

A pilot study of mitochondrial response to an in vivo prosthetic joint Staphylococcus aureus infection model.

Prosthetic joint infections (PJI) are associated with orthopaedic morbidity and mortality. Mitochondria, the "cell's powerhouses," are thought to play crucial roles in infection response and in increased risk of sepsis mortality. No current research discusses PJI's effect on mitochondrial function and a lack of understanding of immune-infection interactions potentially hinders patient care. The purpose of this pilot study was to evaluate the impact of simulated PJI on local tissue mitochondrial function. Using an established prosthetic implant-associated in vivo model, tissues were harvested from the surgical limb of a methicillin-sensitive Staphylococcus aureus implant-associated infection group (n = 6) and compared to a noninfected group (n = 6) at postoperative day (POD) 21. Using mitochondrial coupling assays, oxygen consumption rate and extracellular acidification rate were assessed in each group. Electron flow through mitochondrial complexes reflected group activity. Electron Paramagnetic Resonance (EPR) spectrometry measured the oxidizing potential of serum samples from infected versus noninfected groups. On POD21, colony-forming units per gram of tissue showed 5 × 109 in the infected group and 101 in the noninfected group (p < 0.0001). Maximal respiration and oxygen consumption due to adenosine triphosphate synthesis were significantly lower in isolated mitochondria from infected limbs (p = 0.04). Both groups had similar complex I, III, IV, and V activity (p > 0.1). Infected group EPR signal intensity reflecting reactive oxygen species levels was 1.31 ± 0.30 compared to 1.16 ± 0.28 (p = 0.73) in the noninfected group. This study highlights PJI's role in mammalian cell mitochondrial dysfunction and oxidative tissue damage, which can help develop interventions to combat PJI.

How Many Patients Qualify for Extended Oral Antibiotic Prophylaxis Infection Following Primary and Revision Hip and Knee Arthroplasties?

Extended oral antibiotic prophylaxis (EOAP) has been suggested to reduce rates of periprosthetic joint infection (PJI) postoperatively after total joint arthroplasty (TJA). The purpose of this multicenter study is to define how many TJA patients are considered high risk for developing PJI based on published EOAP criteria and determine whether this status is associated with socioeconomic or demographic factors. All primary and aseptic revision TJAs performed in 2019 at three academic medical centers were reviewed. High-risk status was defined based on prior published EOAP criteria. Area deprivation index (ADI) was calculated as a measure of socioeconomic status. Data were reported as means with standard deviation. Both overall and institutional differences were compared. Of the 2,511 patients (2,042 primary and 469 revision) in this cohort, 73.3% met criteria for high risk (primary: 72.9% [1,490] and revision: 74.6% [350]). Patient's race or age did not have a significant impact on risk designation; however, a larger proportion of high-risk patients were women (p = 0.002) and had higher Elixhauser scores (p < 0.001). The mean ADI for high-risk patients was higher (more disadvantaged) than for standard-risk patients (64.0 [20.8] vs. 59.4 [59.4]) (p < 0.001). Over 72% of primary and revision TJA patients at three medical centers met published criteria for EOAP. These patients were more often women, had more comorbidities, and lived in more disadvantaged areas. Our findings suggest that most patients qualify for EOAP, which may call for more stringent criteria on who would benefit extended antibiotic prophylaxis.

A Novel Protocol for Nasal Decolonization Using Prolonged Application of an Alcohol-Based Nasal Antiseptic Reduces Surgical Site Infections in Total Joint Arthroplasty Patients: A Retrospective Cohort Study.

Background: Current nasal decolonization strategies utilize pre-operative agents without consideration for short-term re-colonization or de novo colonization. Many strategies utilize an antibiotic-based agent, raising concerns of limited gram-negative antimicrobial coverage and the emergence of resistant bacterial strains. This study evaluated the clinical utility of a non-antibiotic, alcohol-based nasal decolonization agent in decreasing surgical site infection (SSI) rates after total joint arthroplasty. Patients and Methods: We retrospectively compared an 18-month cohort of elective primary total joint arthroplasty patients treated peri-operatively with an alcohol-based sanitizer to historical controls. The alcohol-based agent was administered pre-operatively the day of surgery and for two weeks after surgery. Patients were followed for 90 days and assessed for signs or symptoms of SSI. Patient and caregiver compliance was recorded. There were 779 patients included in the experimental group and 647 included in the historical control group. Results: Patients receiving alcohol-based nasal decolonization had a lower rate of SSI compared with controls not receiving nasal decolonization (0.64% [5/779] vs. 1.55% [10/647]; p = 0.048; odds ratio, 2.43). Utilization of an alcohol-based nasal sanitizer in the pre-operative and prolonged post-operative setting decreased infection rates by 41.3% in our elective total joint arthroplasty setting. Conclusions: When used pre- and post-operatively, alcohol-based nasal decolonization of bacteria in patients undergoing total joint arthroplasty led to a substantial decrease in SSIs.

Thirty-Day Mortality and Complication Rates in Total Joint Arthroplasty After a Recent COVID-19 Diagnosis: A Retrospective Cohort in the National COVID Cohort Collaborative (N3C).

BACKGROUND: The risk of postoperative complications in patients who had a positive COVID-19 test prior to a total joint arthroplasty (TJA) is unknown. The purpose of this investigation was to study the complications and mortality associated with a recent COVID-19 diagnosis prior to TJA. METHODS: Patients undergoing primary and revision total hip arthroplasties (THAs) or total knee arthroplasties (TKAs) were identified using the National COVID Cohort Collaborative (N3C) Data Enclave. Patients were divided into a COVID-19-positive group (positive polymerase chain reaction [PCR] test, clinical diagnosis, or positive antibody test) and a COVID-19-negative group, and the time from diagnosis was noted. There was no differentiation between severity or acuity of illness available. The postoperative complications reviewed included venous thromboembolism, pneumonia, acute myocardial infarction, readmission rates, and 30-day mortality rates. RESULTS: A total of 85,047 patients who underwent elective TJA were included in this study, and 3,516 patients (4.13%) had had a recent positive COVID-19 diagnosis. Patients diagnosed with COVID-19 at 2 weeks prior to TJA were at increased risk of pneumonia (odds ratio [OR], 2.46), acute myocardial infarction (OR, 2.90), sepsis within 90 days (OR, 2.63), and 30-day mortality (OR, 10.61). CONCLUSIONS: Patients with a recent COVID-19 diagnosis prior to TJA are at greater risk of postoperative complications including 30-day mortality. Our analysis presents critical data that should be considered prior to TJA in patients recently diagnosed with COVID-19. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

EPR Viscometric Measurements Using a 13C-Labeled Triarylmethyl Radical in Protein-based Biotherapeutics and Human Synovial Fluids.

The viscosity measurements are of clinical significance for evaluation of the potential pathological conditions of biological lubricants such as synovial fluids of joints, and for formulation and characterization of peptide- and protein-based biotherapeutics. Due to inherent potential therapeutic activity, protein drugs have proven to be one of the most efficient therapeutic agents in treatment of several life-threatening disorders, such as diabetes and autoimmune diseases. However, home-use applications for treating chronic inflammatory diseases, such as diabetes and rheumatoid arthritis, necessitate the development of high-concentration insulin and monoclonal antibodies formulations for patient self-administration. High protein concentrations can affect viscosity of the corresponding drug solutions complicating their manufacture and administration. The measurements of the viscosity of new insulin analogs and monoclonal antibodies solutions under development is of practical importance to avoid unwanted highly viscous, and therefore, painful for injection drug formulations. Recently, we have demonstrated capability of the electron paramagnetic resonance (EPR) viscometry using viscosity-sensitive 13C-labeled trityl spin probe (13C1-dFT) to report the viscosity of human blood, and interstitial fluids measured in various organs in mice ex-vivo and in anesthetized mice, in vivo. In the present work, we demonstrate utility of the EPR viscometry using 13C1-dFT to measure microviscosity of commercial insulin samples, antibodies solution, and human synovial fluids using small microliter volume samples (5-50 µL). This viscometry analysis approach provides useful tool to control formulations and administration of new biopharmaceuticals, and for evaluation of the state of synovial fluids of importance for clinical applications.

A Pilot Study Using a Standardized Method of Measuring Distress Demonstrates Higher Levels in Septic Revisions.

Background: Combined Orthopaedic Infectious Disease Clinics facilitate care for prosthetic joint infection (PJI) patients similar to multidisciplinary care in cancer centers. The National Comprehensive Cancer Network developed a standardized distress thermometer (DT) to measure distress in cancer patients. We propose using this tool to assess distress in PJI patients. Methods: In this pilot study, a retrospective review of patients treated in our combined clinic over 2 years was conducted. In addition to providing information surrounding their treatment, patients completed a questionnaire and DT, adapted with permission from the National Comprehensive Cancer Network. DT scores were compared to a chronologically collected matched aseptic control group. Results: There were 122 patients in the septic group and 40 patients in the aseptic group. On a scale of 0-10 (10, the highest level of distress), the septic group reported a mean DT score of 6.18 (±3.2), which was significantly higher than the aseptic mean score of 3.33 (±2.06) [P < .0001]. Over 75% of patients in the septic group reported a DT score ≥4, the cutoff used in most cancer centers to warrant additional support. Twenty-one percent of the septic group (26/122) reported extreme distress (defined as a score ≥10) compared to 0/40 of aseptic patients. Conclusions: Patients treated for PJI experience significantly higher levels of distress compared to aseptic revision patients. More attention is needed to measure and clinically address distress. Improved screening for distress would allow us to provide more comprehensive care and possibly improve compliance, outcomes, and resources available for the treatment of PJI patients.

Randomized Trial of Postoperative Venous Thromboembolism Prophylactic Compliance: Aspirin and Mobile Compression Pumps.

BACKGROUND: Aspirin, as a routine venous thromboembolism (VTE) prophylaxis, is approved along with pneumatic compression pumps by the American College of Chest Physicians. We assessed compliance of aspirin and pump use after total joint arthroplasty. METHODS: A randomized trial of aspirin alone or aspirin/mobile compression pumps after total joint arthroplasty was performed. Aspirin and pump compliance, VTE events, and satisfaction with pump use were collected. Compliance was assessed through an internal device monitor and drug log book. Patients were also contacted 90 days postoperatively for reported symptomatic VTEs. RESULTS: Each group had 40 patients and greater than 94% compliance with aspirin use, with no difference between groups (P = 0.55). Overall pump compliance during the first 14 days after hospital discharge was 51% (SD ± 33), which was significantly worse than aspirin compliance at 99% (SD ± 4.1) (P < 0.0001). Only 10 patients were compliant (>20 hr/d) with recommended pump use throughout the entire recommended period. There was no notable association between aspirin compliance and VTE within 90 days. There was no notable association between pump compliance and VTE at 90 days. However, average pump use compliance was 20% in patients with VTE and 54% in patients without VTE within 90 days. With the numbers available in this compliance study, there was no significant difference (P = 0.11). DISCUSSION: Aspirin compliance was notably greater than pump compliance. In this study, we found that pump compliance was not associated with lower VTE risk. In fact, no increased risk was recognized in patients with an average pump usage of >50%. Further study is warranted to define the duration of pump use required for clinical significance. The recommended use of compression pumps should continue to be examined.

Intravenous antibiotic duration in the treatment of prosthetic joint infection: systematic review and meta-analysis.

Introduction: Long antibiotic courses, including intravenous (IV) and oral administrations, are utilized in prosthetic joint infection (PJI) treatment. This meta-analysis examines the non-inferiority of short courses ( <  4 weeks) of IV antibiotics compared to long courses in treating PJI. Critical review of IV treatment is necessary due to the clinical, physical, and financial burden associated with it and its continued prolonged use in the US without much evidence to support the practice. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), databases were searched using predefined medical subject headings (MeSH). Results: The nine included studies reported 521 total hip arthroplasties (THAs) and 530 total knee arthroplasties (TKAs). There was no significant difference in the overall success rate in short- vs. long-duration IV antibiotics for PJI treatment: odds ratio (OR) of 1.65, 95 % confidence interval (CI) of 0.78-3.46, and p = 0 .18. However, due to the moderate to high heterogeneity ( I 2 = 68  %, p   <  0.01) amongst studies, an adjusted success rate was calculated after the exclusion of two studies. This showed a statistically significant difference between both groups (OR of 2.45, 95 % CI of 1.21-4.96, p   <  0.001) favoring a short course of antibiotics and reflecting a more homogenous population ( I 2 = 51  %, p = 0 .06). Conclusion: This study highlights the limited data available for evaluating IV antibiotic duration in the setting of PJI. We found that a shorter duration of IV antibiotics was non-inferior to a longer duration, with an improved OR of 2.45 for treatment success, likely shortening inpatient stay as well as lessening side effects and antimicrobial resistance with a lower cost to patients and overall healthcare.

Flip Autograft Technique for Anterolateral Femoral Deficiency in Total Knee Arthroplasty.

Anterolateral bone loss of the femur within the trochlear groove presents a unique and rare issue in primary total knee arthroplasty (TKA). Unlike distal and posterior femur bone loss for which most contemporary TKA systems have modular augments, the same does not exist for anterolateral bone loss. We present a technique in which a patient's host bone from the standard distal femoral cuts was used to augment and provide a stable base for cementing of final femoral implants. Currently, the patient has 3-year follow-up with excellent results in terms of pain control with no evidence of component failure on the most recent radiographs. This technique provides a simple solution to a complex problem within primary TKA.

Thromboelastography is predictive of mortality, blood transfusions, and blood loss in patients with traumatic pelvic fractures: a retrospective cohort study.

PURPOSE: In patients with traumatic pelvic fractures, thromboelastography (TEG) is a useful tool to rapidly evaluate and identify coagulation disturbances. The purpose of this study was to examine the coagulation kinetics of patients with traumatic pelvic fractures (pelvic ring and/or acetabulum) by analyzing the TEG results at initial presentation and its relationship with mortality and blood loss. METHODS: A retrospective review at our Level-1 trauma center was conducted to identify Full Trauma Team activations (FTTa) with traumatic pelvic and/or acetabular fractures who were evaluated with a TEG on initial presentation between 2012 and 2016. In-hospital mortality, product transfusion, and hemoglobin changes were analyzed. Subgroup analysis was performed based on pelvic fracture type. RESULTS: 141 patients with a mean age of 49.0 ± 20.8 years and mean Injury Severity Score (ISS) of 25.18 ± 12.8 met inclusion criteria. PRBC transfusion occurred in 78.0% of patients; a total of 1486 blood products were transfused. A total of 65 patients (46.1%) underwent operative treatment for the pelvic injuries, and 18 patients (12.7%) required embolization. The overall in-hospital mortality rate was 14.9%. The degree of clot lysis at 30 min (LY30) was significantly associated with blood loss (p < 0.0001), units of packed red blood cells (PRBCs) transfused (p < 0.0001), and mortality rate (p = 0.0002). CONCLUSION: Increased fibrinolysis evidenced by an elevated LY30 on initial TEG in patients with traumatic pelvic fractures is associated with increased blood loss, blood product transfusions, and mortality. Future studies should evaluate the clinical utility of reversing hyperfibrinolysis on initial TEG. LEVEL OF EVIDENCE: Prognostic level III.

A Medial Congruent Polyethylene Offers Satisfactory Early Outcomes and Patient Satisfaction in Total Knee Arthroplasty.

BACKGROUND: Although a successful operation, almost 20% of patients are dissatisfied with total knee arthroplasty (TKA). The purpose of this retrospective cohort study was to see if a medial congruent (MC) polyethylene would offer satisfactory early outcomes and patient satisfaction after TKA. METHODS: We reviewed prospectively collected data on 327 TKAs using multiple bearings within the same implant system. Ninety-six received an MC bearing, 70 received a cruciate-retaining (CR) bearing, and 161 received a posterior-stabilized (PS) bearing. We evaluated the visual analog scale pain scores and range of motion (ROM) at 2 weeks, 6 weeks, 3 months, and 1 year; Patient-Reported Outcomes Measurement Information System (PROMIS-10) score and Knee Injury and Osteoarthritis Outcome Score (KOOS) at 3 months and 1 year; and Forgotten Joint Score (FJS-12) at 1 year. RESULTS: All groups had similar KOOS and PROMIS-10 scores. MC knees had lower visual analog scale scores than PS knees at all time points (P < .05) and a higher ROM than PS at 2 weeks (98.6 vs 93.7, P = .002). MC knees had a significantly higher FJS-12 than CR knees (71.6 vs 58.7, P = .02). More MC knees were "very satisfied" than CR (92.6% vs 81.5%, P = .04). Fewer MC knees were "not at all satisfied" than CR (1.2% vs 9.2%, P = .04). There were similar satisfaction ratings with MC and PS. CONCLUSIONS: An MC bearing provided similar or improved early pain, ROM, KOOS, PROMIS-10, FJS-12, and patient satisfaction as compared with standard bearings in TKA.

The Effect of the COVID-19 Pandemic on Hip and Knee Arthroplasty Patients in the United States: A Multicenter Update to the Previous Survey.

BACKGROUND: In March 2020, elective total hip and knee arthroplasty (THA and TKA) were suspended across the United States in response to the COVID-19 pandemic. We had previously published the results of a survey to the affected patients from 6 institutions. We now present the results of a larger distribution of this survey, through May and June 2020, to electively scheduled patients representing different regions of the United States. METHODS: Fifteen centers identified through the American Association of Hip and Knee Surgeons Research Committee participated in a survey study of THA and TKA patients. Patients scheduled for primary elective THA or TKA but canceled due to the COVID-19 elective surgery stoppage (3/2020-5/2020) were included in the study. Descriptive statistics along with subgroup analysis with Wilcoxon rank were performed. RESULTS: In total, surveys were distributed to 2135 patients and completed by 848 patients (40%) from 15 institutions. Most patients (728/848, 86%) had their surgery postponed or canceled by the surgeon or hospital. Unknown length of surgical delay remained the highest source of anxiety among survey participants. Male patients were more likely to be willing to proceed with surgery in spite of COVID-19. There were minimal regional differences in responses. Only 61 patients (7%) stated they will continue to delay surgery for fear of contracting COVID-19 while in the hospital. CONCLUSION: Similar to the previous study, the most anxiety-provoking thought was the uncertainty, over if and when the canceled joint replacement surgery could be rescheduled. Patients suffering from the daily pain of hip and knee arthritis who have been scheduled for elective arthroplasty remain eager to have their operation as soon as elective surgery is allowed to resume.

Tissue-level cytokines in a rodent model of chronic implant-associated infection.

Systemic cytokine concentrations have been extensively studied in implant-associated infections, providing sensitive diagnostic markers. However, less is known about the relationships of tissue-level cytokines surrounding the joint. The aim of this study was to define the cytokine profiles of tissues to investigate the use of these cytokines as markers of debridement in chronic joint infection. Using a rodent model, muscle samples were obtained from rats following Kirschner wire implantation and infection with Staphylococcus aureus to determine if: (1) differences exist in cytokine concentrations with proximity to infection, and (2) localized infection-specific markers can be identified on a tissue level to potentially serve as debridement markers in the future. Samples were collected from 4 distinct locations, and the concentrations of interleukin(IL)-1α, IL-1ß, IL-4, IL-5, IL-6, IL-10, IL-12p70, IL-13, granulocyte-macrophage colony-stimulating factor, interferon-γ, and tumor necrosis factor-α were quantified in each sample, relative to the amount of tissue. Cytokine concentrations differed with proximity to the joint when implant or infection was present, and tissues at the operative knee joint showed the highest levels of most cytokines. Additionally, IL-1ß, IL-4, and IL-6 showed promise, beyond diagnostics, as tissue-level indicators of infection response. Ultimately, this study illustrated that tissue-level evaluation provided insight into infection-specific response, and these markers may be useful for guiding the debridement of implant-associated infections.

Localized cytokine responses to total knee arthroplasty and total knee revision complications.

BACKGROUND: The study of localized immune-related factors has proven beneficial for a variety of conditions, and one area of interest in the field of orthopaedics is the impact of implants and localized infections on immune response. Several cytokines have shown increased systemic concentrations (in serum/plasma) in response to implants and infection, but tissue-level cytokines have not been investigated as thoroughly. METHODS: This exploratory study investigated tissue-level cytokines in a cohort of patients (N = 17) in response to total knee arthroplasty and total knee revision to better understand the immune response to implants and localized infection (e.g., prosthetic joint infection). The overall goal of this study was to provide insight into the localized cytokine response of tissues and identify tissue-level markers specific to inflammation caused by implants vs. inflammation caused by infection. Tissues were collected across several anatomical locations and assayed with a panel of 20 human inflammatory cytokines to understand spatial differences in cytokine levels. RESULTS: In this study, six cytokines were elevated in implanted joints, as compared to native joints: IL-10, IL-12p70, IL-13, IL-17A, IL-4, and TNF-α (p < 0.05). Seven cytokines showed infection-dependent increases in localized tissues: IL-1α, IL-1ß, IL-6, IL-8, MCP-1, MIP-1α, and MIP-1ß (p < 0.05). CONCLUSIONS: This study demonstrated that differences exist in tissue-level cytokines in response to presence of implant, and some cytokines were specifically elevated for infection; these responses may be informative of overall tissue health. These results highlight the utility of investigating localized cytokine concentrations to offer novel insights for total knee arthroplasty and total knee revision procedures, as well as their complications. Ultimately, this information could provide additional, quantitative measurements of tissue to aid clinical decision making and patient treatment options.

Impact of Cytokines and Phosphoproteins in Response to Chronic Joint Infection.

The early cellular response to infection has been investigated extensively, generating valuable information regarding the mediators of acute infection response. Various cytokines have been highlighted for their critical roles, and the actions of these cytokines are related to intracellular phosphorylation changes to promote infection resolution. However, the development of chronic infections has not been thoroughly investigated. While it is known that wound healing processes are disrupted, the interactions of cytokines and phosphoproteins that contribute to this dysregulation are not well understood. To investigate these relationships, this study used a network centrality approach to assess the impact of individual cytokines and phosphoproteins during chronic inflammation and infection. Tissues were taken from patients undergoing total knee arthroplasty (TKA) and total knee revision (TKR) procedures across two tissue depths to understand which proteins are contributing most to the dysregulation observed at the joint. Notably, p-c-Jun, p-CREB, p-BAD, IL-10, IL-12p70, IL-13, and IFN-γ contributed highly to the network of proteins involved in aseptic inflammation caused by implants. Similarly, p-PTEN, IL-4, IL-10, IL-13, IFN-γ, and TNF-α appear to be central to signaling disruptions observed in septic joints. Ultimately, the network centrality approach provided insight into the altered tissue responses observed in chronic inflammation and infection.

Portable compression devices in total joint arthroplasty: poor outpatient compliance.

BACKGROUND: Aspirin and mechanical compression devices are approved means of venous thromboembolism (VTE) prophylaxis after total joint arthroplasty. Prior studies of mechanical compression pumps after joint arthroplasty have been limited to the inpatient setting. The purpose of this study was to evaluate outpatient compliance and utilization factors in a rural population after elective hip or knee arthroplasty. METHODS: Utilization for portable pneumatic compression pumps after joint arthroplasty was prospectively recorded (hours). Compliance was defined as the recommended 20 hours per day. A questionnaire 2 weeks postoperatively assessed factors that may contribute to noncompliance. Patients were followed up for 90 days postoperatively to record VTE events. RESULTS: Data were collected for 115 joint arthroplasty patients (50 hips, 65 knees). Postdischarge day one had the highest average usage at 13.2 hours/day (66.0%, range 0%-100%), but this number fell to 4.8 hours/day (24.0, range 0%-100%) by day 14. Patient compliance (>20 hours use/day) was highest on postdischarge day one at 40 patients (34.7%). By postdischarge day 14, patient compliance fell to 17 patients (14.8%). Difficulty using the pumps (P = .027) and pump-associated heat (P = .009) were significantly associated with patient compliance. A deep vein thrombosis and nonfatal pulmonary embolism were recorded in 2 separate patients. CONCLUSIONS: This study demonstrated poor outpatient compliance with portable pneumatic compression devices. Poor compliance was related to pump heat and difficulty with pump use. Even with poor compliance, a low incidence of VTE events was observed.

Liposomal Bupivacaine Offers No Benefit Over Ropivacaine for Multimodal Periarticular Injection in Total Knee Arthroplasty.

Local infiltration analgesia has become a mainstay of pain control for total knee arthroplasty. This study compared the efficacy and cost between periarticular injection cocktails containing liposomal bupivacaine vs ropivacaine. Two hundred forty-two primary total knee arthroplasties performed between September 2013 and January 2016 were retrospectively reviewed. All patients received similar pre-operative medications and a periarticular injection. The control group received 300 mg of ropivacaine, while the study group received liposomal bupivacaine. All patients received the same preoperative, intraoperative, and postoperative adjunct medications. Visual analog scale pain scores, narcotic requirements, distance walked, range of motion, length of stay, Knee Society Scores, and need for manipulation under anesthesia were recorded. Mean visual analog scale pain score 23 to 32 hours postoperatively, mean visual analog scale pain score during the entire hospitalization, and length of stay were lower in the ropivacaine group compared with the liposomal bupivacaine group. Knee range of motion was higher at 2 weeks in the ropivacaine group. There were no statistically significant differences in the other outcome measures. The cost of ropivacaine was considerably lower than the cost of liposomal bupivacaine. Bupivacaine added to liposomal bupivacaine addressed the delayed onset of this medication and gave an accurately matched comparison with the ropivacaine cocktail. All outcomes tested with liposomal bupivacaine were either equivalent or inferior to those with ropivacaine. When used as a component of a periarticular injection cocktail, liposomal bupivacaine offers no advantages over ropivacaine and has a considerably higher cost. [Orthopedics. 2020; 43(2):91-96.].

The Effect Of Increasing Femoral Head Size On The Force Required For Dislocation.

Alternative bearings allow for the increased utilization of large femoral heads in total hip arthroplasty. This study demonstrated the effect of increasing femoral head size on the force required for dislocation during intraoperative assessment. Using a standard posterior approach, 10 cadaver hips underwent total hip arthroplasty; components were implanted in a standard fashion. The extremity was attached to a custom jig to replicate intraoperative assessment (internal rotation with 90° of hip flexion/neutral adduction). This range of motion (ROM) was repeated in triplicate using femoral head sizes of 28mm, 32mm, 36mm, 40mm, and 44mm. The ROM to dislocation (degrees) and torque (N*m) required were recorded. With increasing head sizes, there was a significant increase in torque required for dislocation (p<0.0001). The least square means torques (N*m) for each femoral head size (28-44mm) were 2.07, 2.15, 2.42, 2.74, and 3.65N*m. The corresponding least square means ROMs prior to dislocation were 43.5°, 46.2°, 50.8°, 54.3°, and 59.5°. There was a significant difference in ROM between nonadjacent head sizes (i.e., 28mm and 44mm) (p<0.0001). Total hip implant stability is multifactorial. Increasing femoral head size may confer stability during intraoperative assessment by increasing both the ROM prior to dislocation and the force required for dislocation.