Mepivacaine Versus Bupivacaine Spinal Anesthesia for Primary Total Joint Arthroplasty: A Systematic Review and Meta-Analysis.

BACKGROUND: Mepivacaine is an intermediate acting amide local anesthetic that can be used for neuraxial anesthesia in total joint arthroplasty (TJA) with a shorter duration of action (1.5-2 hours) compared to the more commonly used local anesthetic bupivacaine. The purpose of this study was to perform a systematic review and meta-analysis comparing bupivacaine and mepivacaine spinal anesthesia during elective TJA and the surgical outcomes of the time to full neurologic motor return, pain, mobility, length of stay (LOS), and complications including transient neurologic symptoms and urinary function. METHODS: PubMed, Ovid MEDLINE, and Ovid Embase were screened for "arthroplasty, spinal anesthesia, bupivacaine, and mepivacaine," in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A total of 159 studies were screened and 5 studies were evaluated. Data were compared regarding motor function return, mobility (distance ambulated), pain (visual analog scale [VAS]), LOS, and postoperative complications. RESULTS: Full-text screening yielded 5 studies (3 randomized controlled trials and 2 retrospective cohort studies), with a total of 1,550 patients. Mepivacaine spinals had an earlier return to motor function (154 minutes vs 170 minutes, 95% CI: [-31.6, -0.9], P = .04), shorter LOS (25.95 hours vs 29.96 hours, 95% CI: [-6.8, -1.2], P = .01), and decreased urinary retention (7.15% vs 10.58%, 95% CI: [-6.3%, -0.6%], P = .02) with no differences in pain (VAS 3.57 vs 3.68, 95% CI: [-2.1, 1.9], P = .90) or distance ambulated (94.2 ft vs 89.1 ft, 95% CI: [-15, 25.2], P = .60) compared to bupivacaine spinal anesthesia. CONCLUSIONS: The method of anesthesia administration has been an increasing area of focus for quicker and safer recovery to allow for early ambulation and facility discharge. The rapid recovery facilitated by mepivacaine may further enable outpatient TJA and enhance patient recovery. LEVEL OF EVIDENCE: III.

A novel activated-zinc antiseptic solution effective against MRSA and Pseudomonas aeruginosa: a pig model.

OBJECTIVE: The purpose of this study was to investigate the antimicrobial efficacy of a novel activated zinc solution against meticillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa after one hour, and to evaluate any untoward effect of the solution on local wound tissue at 24 hours after solution exposure in a pig wound model. METHOD: A pathogen-free, commercially raised, Yorkshire-cross female pig was acquired 12 days prior to the procedure. Within one week prior to the procedure, a small loopful of test bacteria, Pseudomonas aeruginosa (pig-isolate) and MRSA (ATCC-6538), were streaked and cultured on a non-selective agar. Full-thickness wounds (n=24) were created and evenly divided into three groups: control wounds (exposed to bacteria but untreated, n=8); wounds treated with Compound 1 (n=8), and wounds treated with Compound 2 (n=8). All wounds were dressed and monitored for one hour and 24 hours. RESULTS: After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable total bacteria of 2.8 log colony forming units (CFUs) and 3.5 logCFUs, respectively. After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable MRSA of 2.3 logCFUs and 1.6 logCFUs, respectively (p=0.009). After one hour, the wounds treated with Compound 1 and Compound 2 had a mean recoverable Pseudomonas aeruginosa of 0.3 logCFUs and 0.0 logCFUs, respectively (p=0.000). After 24 hours of exposure to Compound 1 and Compound 2, there was no statistically significant increased necrosis (p=0.12, p=0.31, respectively) or neutrophilic infiltrate (Compound 2, p=0.12) when compared with control wounds. CONCLUSION: The novel activated-zinc compound used in this study demonstrated a 99.5-99.9% reduction in total bacteria, a 99.9-99.98% reduction in MRSA, and 100% eradication of Pseudomonas aeruginosa one hour after exposure. This novel solution may provide another significant tool to treat and/or prevent wound infections.

A Novel Activated Zinc Solution with Improved Efficacy Against Pseudomonas and MRSA Biofilm Compared to Chlorhexidine and Povidone-Iodine.

INTRODUCTION: The search for the optimal agent for infection eradication in periprosthetic joint infection (PJI) remains challenging as there are limited efficacious and safe options. The ideal solution should have significant bactericidal and anti-biofilm activity to be able to eradicate infection with the preservation of prosthetic components. Therefore, the purpose of this study was to 1) investigate the anti-biofilm efficacy of a novel activated zinc solution against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) biofilm in vitro and 2) compare its efficacy against two leading commercially available antimicrobial irrigants (CHG and 0.35% povidone-iodine [PI]). MATERIALS AND METHODS: A modified Robbins device (MRD) was utilized to replicate Pseudomonas aeruginosa and MRSA biofilms. The primary outcome was to determine bacterial reduction after two hours of biofilm exposure to an activated zinc solution, CHG, and PI, and compare to untreated controls. RESULTS: Against Pseudomonas biofilm, activated zinc demonstrated a 4.5-log (99.996%) reduction, chlorhexidine demonstrated a 0.9-log (87.4%) reduction (p<0.001), and PI demonstrated a 0.8-log (83.1%) reduction (p<0.001). After two hours of exposure, activated zinc had undetectable MRSA with a 7.08-log (100%) reduction, chlorhexidine had a 1.9-log (98.7%) reduction (p<0.01), and PI had a 3.2-log (99.9%) reduction (p<0.01). CONCLUSIONS: Our novel activated zinc compound demonstrated a 99.996% reduction in Pseudomonas biofilm and a 100% reduction in MRSA biofilm. This novel solution may provide a significant tool in the arsenal to treat and/or prevent PJI and other wound infections. Future in vivo studies are warranted to demonstrate clinical utility, efficacy, and safety.

Effectiveness of Autologous Fat Transfer in the Treatment of Scar-Related Conditions: A Systematic Review and Meta-analysis.

BACKGROUND AND AIM: Autologous fat transfer (AFT) has been introduced as a potential treatment option for scar-tissue and its related symptoms. However, the scientific evidence for its effectiveness remains unclear. This meta-analysis aims to evaluate the available evidence regarding the effectiveness of autologous fat transfer for the treatment of scar-tissue and its related conditions. METHODS: PubMed/Medline database was queried from its inception till the end of November 2021. All the relevant studies assessing the effect of autologous fat transfer in the treatment of scar-related conditions were pooled in using a random-effects model. RESULTS: 9 studies (n=179) were included in the meta-analysis. Pooled analysis demonstrates significant improvement in all subscales of the POSAS patient score with most prominent in color 2.4 points (95% CI 1.78-3.041), stiffness 2.9 points (95% CI 2.33-3.45), irregularity 2.2 points (95% CI 1.093-3.297) and thickness 1.8 points (95% CI 0.804-2.719), respectively. Pain and itch improved relatively lesser, 1.3 points (95% CI 0.958-1.674) and 0.6 points (95% CI 0.169-1.215), respectively. The POSAS observer scale showed a relatively lower improvement with the least in vascularity 0.5 points (95% CI 0.098-0.96), pigmentation 0.8 points (95% CI 0.391-1.276) and surface area 0.8 points (95% CI 0.34-1.25). Thickness improved by 1.4 points (95% CI 0.582-2.3), relief 1.0 points (95% CI 0.461-1.545) and pliability 1.5 points (95% CI 1.039-2.036). CONCLUSION: Our findings demonstrate that autologous fat transfer (AFT) is a promising treatment for scar-related conditions as it provides beneficial results in the scar quality. Future research should focus on the long-term effects of AFT and high-level evidence studies such as, randomized controlled trials (RCTs) and cohort studies are required. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Demographic, comorbidity, and episode of care trends in unicompartmental knee arthroplasty: 2008 to 2018.

PURPOSE: The purpose of this study is to assess how unicompartmental knee arthroplasty (UKA) patient demographics, comorbidities, and episode of care outcomes have changed from 2008 to 2018 in order to better understand the impact of recent changes in healthcare ideology on UKA. METHODS: The National Surgical Quality Improvement Program was queried to identify demographics, comorbidities, and episode of care outcomes in patients undergoing primary UKA from 2008 to 2013 (n = 3096) vs 2014-2018 (n = 9073). Trends were analyzed using Student's t-tests for continuous variables and Chi-squared tests and Fisher's exact tests for categorical variables. RESULTS: When comparing the years 2008-2013 to 2014-2018, there was no clinically significant difference in age, body mass index (BMI), proportion of patients with a BMI > 40 kg/m2, percentage of diabetes (15.0% vs 15.5; p = 0.715), smoking status (10.2% vs 9.4%; 0.177), COPD (3.0% vs 2.8%; p = 0.645), CHF within 30 days (< 0.1% vs 0.2%; p = 0.060), or acute renal failure (0.0% vs < 0.1%; p = 0.621) in patients undergoing UKA. However, the rate of patients with dyspnea, (5.7% versus 3.6%; p < 0.001), anemia (9.4 versus 7.3%; p < 0.001), and overall morbidity/mortality probability have improved, with a decrease in hospital LOS (2.2 ± 1.9 days versus 1.4 ± 2.1 days; p < 0.001) and an increase in home-discharge (90.7% versus 95.2%; p < 0.001). CONCLUSION: From 2008 to 2018, there was minimal improvement in UKA patients' modifiable comorbidities. However, despite the lack of significant change in patient health status, our findings showed improvement in episode-of-care outcomes, implying that the value of UKA has been increasing over the last decade.

How Accurate Is ICD-10 Coding for Revision Total Knee Arthroplasty?

BACKGROUND: The International Classification of Diseases-10 (ICD-10) came into effect in October 2015. The new procedural codes (ICD-10-PCS) were designed to specify granular aspects of the procedure, including laterality and revised components. This specificity could improve data collection in institutional databases, large registries, and administrative claims data. Given these possible applications, this study's purpose was to assess the accuracy of ICD-10-PCS coding for revision total knee arthroplasty (rTKA). METHODS: This multicenter retrospective analysis utilized the rTKA databases at four academic medical centers for all aseptic rTKAs between October 1, 2015 and July 3, 2019. Operative reports were reviewed to determine laterality and revised components (tibial, femoral, liner, and patellar component), which were then compared with the ICD-10-PCS codes associated with the billing records. Proper coding required both component removal and replacement codes. The correct series of removal and replacement codes was determined using the American Joint Replacement Registry's guidelines. RESULTS: In total, 1906 rTKAs were examined, and 98.0% had at least one proper ICD-10-PCS code, indicating an rTKA had occurred. Coding for components replaced was correct in 76.3% of cases. When examining both removal and replacement codes, accuracy dropped to 57.0%. CONCLUSION: Nearly 25% of rTKA procedures were incorrectly coded for replaced components, and over 40% were incorrectly coded for removed and replaced components. ICD-10-PCS codes can accurately identify that an rTKA has occurred; however, the inaccuracy in identifying which specific components were revised should prompt further evaluation of the coding process before utilizing ICD-10-PCS codes to report granular rTKA data. LEVEL OF EVIDENCE: III, retrospective observational analysis.

What Is the Optimal Irrigation Solution in the Management of Periprosthetic Hip and Knee Joint Infections?

BACKGROUND: Thorough irrigation and debridement using an irrigation solution is a well-established treatment for both acute and chronic periprosthetic joint infections (PJIs). In the absence of concrete data, identifying the optimal irrigation agent and protocol remains challenging. METHODS: A thorough review of the current literature on the various forms of irrigations and their additives was performed to evaluate the efficacy and limitations of each solution as pertaining to pathogen eradication in the treatment of PJI. As there is an overall paucity of high-quality literature comparing irrigation additives to each other and to any control, no meta-analyses could be performed. The literature was therefore summarized in this review article to give readers concise information on current irrigation options and their known risks and benefits. RESULTS: Antiseptic solutions include povidone-iodine, chlorhexidine gluconate, acetic acid, hydrogen peroxide, sodium hypochlorite, hypochlorous acid, and preformulated commercially available combination solutions. The current literature suggests that intraoperative use of antiseptic irrigants may play a role in treating PJI, but definitive clinical studies comparing antiseptic to no antiseptic irrigation are lacking. Furthermore, no clinical head-to-head comparisons of different antiseptic irrigants have identified an optimal irrigation solution. CONCLUSION: Further high-quality studies on the optimal irrigation additive and protocol for the management of PJI are warranted to guide future evidence-based decisions.

2018 John Charnley Award: Analysis of US Hip Replacement Bundled Payments: Physician-initiated Episodes Outperform Hospital-initiated Episodes.

BACKGROUND: The Centers for Medicare & Medicaid Services (CMS) launched the Bundled Payment for Care Improvement (BPCI) initiative in 2013 to create incentives to improve outcomes and reduce costs in various clinical settings, including total hip arthroplasty (THA). This study seeks to quantify BPCI initiative outcomes for THA and to determine the optimal party (for example, hospital versus physician group practice [PGP]) to manage the program. QUESTIONS/PURPOSES: (1) Is BPCI associated with lower 90-day payments, readmissions, or mortality for elective THA? (2) Is there a difference in 90-day payments, readmissions, or mortality between episodes initiated by PGPs and episodes initiated by hospitals for elective THA? (3) Is BPCI associated with reduced total Elixhauser comorbidity index or age for elective THA? METHODS: We performed a retrospective analysis on the CMS Limited Data Set on all Medicare primary elective THAs without a major comorbidity performed in the United States (except Maryland) between January 2013 and March 2016, totaling more than USD 7.1 billion in expenditures. Episodes were grouped into hospital-run BPCI (n = 42,922), PGP-run BPCI (n = 44,662), and THA performed outside of BPCI (n = 284,002). All Medicare Part A payments were calculated over a 90-day period after surgery and adjusted for inflation and regional variation. For each episode, age, sex, race, geographic location, background trend, and Elixhauser comorbidities were determined to control for major confounding variables. Total payments, readmissions, and mortality were compared among the groups with logistic regression. RESULTS: When controlling for demographics, background trend, geographic variation, and total Elixhauser comorbidities in elective Diagnosis-Related Group 470 THA episodes, BPCI was associated with a 4.44% (95% confidence interval [CI], -4.58% to -4.30%; p < 0.001) payment decrease for all participants (USD 1244 decrease from a baseline of USD 18,802); additionally, odds ratios (ORs) for 90-day mortality and readmissions were unchanged. PGP groups showed a 4.81% decrease in payments (95% CI, -5.01% to -4.61%; p < 0.001) after enrolling in BPCI (USD 1335 decrease from a baseline of USD 17,841). Hospital groups showed a 4.04% decrease in payments (95% CI, -4.24% to 3.84%; p < 0.01) after enrolling in BPCI (USD 1138 decrease from a baseline of USD 19,799). The decrease in payments of PGP-run episodes was greater compared with hospital-run episodes. ORs for 90-day mortality and readmission remained unchanged after BPCI for PGP- and hospital-run BPCI programs. Patient age and mean Elixhauser comorbidity index did not change after BPCI for PGP-run, hospital-run, or overall BPCI episodes. CONCLUSIONS: Even when controlling for decreasing costs in traditional fee-for-service care, BPCI is associated with payment reduction with no change in adverse events, and this is not because of the selection of younger patients or those with fewer comorbidities. Furthermore, physician group practices were associated with greater payment reduction than hospital programs with no difference in readmission or mortality from baseline for either. Physicians may be a more logical group than hospitals to manage payment reduction in future healthcare reform. LEVEL OF EVIDENCE: Level II, economic and decision analysis.

Intra-articular Corticosteroid Injection Following Total Knee Arthroplasty: Is It Effective?

BACKGROUND: Total knee arthroplasty (TKA) for the majority of patients with severe knee osteoarthritis provides relief of symptoms and improved function. However, there remains a subset of dissatisfied patients despite an unremarkable workup. A corticosteroid injection (CSI) is a commonly used nonsurgical treatment for painful knee osteoarthritis but its efficacy in a replaced knee remains unknown. METHODS: A retrospective chart review identified primary TKA patients who subsequently received a CSI into a replaced knee from 2015 to 2016 by a single surgeon. Patients receiving a CSI underwent clinical examination, laboratory analysis to rule out infection, and radiographic evaluation before CSI. Patient variables were recorded and a patient satisfaction survey assessed the efficacy of the injection. The survey response rate was 70.1%. RESULTS: Of the 129 responders, 82.9% remembered the injection. The average time from index arthroplasty to injection was median 5.3 months (interquartile range, 2.1-23.4) and 30.8% of patients received more than 1 injection (range, 1-5). Overall, 76.6% reported decreased pain, 57.9% reported increased motion, and 65.4% reported long-term decreased swelling. Improvement lasted greater than 1 month for 56.1% of patients, and overall 84.1% reported improvement (slight to great) in the knee following CSI. No patient developed a periprosthetic joint infection (PJI) within 1 year of injection. CONCLUSION: This study suggests that certain patients following TKA may benefit from a CSI. However, this should only be performed once clinical, radiographic, and laboratory examination has ruled out conditions unlikely to improve long term from a CSI.

Role of Anatomical Patella Replacement on Anterior Knee Pain.

BACKGROUND: Anterior knee pain (AKP) remains a complex issue affecting patient satisfaction after total knee arthroplasty. Several radiographic parameters have been shown to be causative factors with various designs. The aim of this study is to evaluate the known radiographic parameters of AKP and clinical outcomes (ie, AKP) in the setting of a modern prosthesis with an anatomic patella button. METHODS: Between July 2012 and December 2013, 90 total knee arthroplasties received 3 skyline views taken at 30°, 45°, and 60°. A patient-administered questionnaire was administered at 2-year follow-up to assess the incidence of AKP, painless noise, and satisfaction. Radiographs were analyzed for patellofemoral overstuffing, patellar tilt, and patellar displacement, and evaluated the patella resection angle. RESULTS: On the patient-administered questionnaire, 10 (11.1%) patients reported AKP of a mild-to-moderate nature. Thirty-one had the best view at 30 Merchant views, 24 had best views at 45, and 35 had best views at 60. We found that patellar resection angle correlated with AKP (odds ratio 1.21, P = .044) and painless noise (odds ratio 1.22, P = .034). Patellar displacement and patellofemoral stuffing did not correlate with AKP or painless noise. No radiographic measurements correlated with changes in Knee Society Score pain or function scores or range of motion. CONCLUSION: We found that a patellar resection angle correlated with the incidence of AKP and painless noise at 2-year follow-up. We failed to find any correlation with patellofemoral overstuffing, patellar displacement, or patellar tilt with clinical outcomes. We recommend the use of 3 Merchant views to fully evaluate the patellofemoral joint.

Primary Total Knee Arthroplasty Implants as Functional Prosthetic Spacers for Definitive Management of Periprosthetic Joint Infection: A Multicenter Study.

BACKGROUND: There are limited data on the utility of a standard primary total knee arthroplasty (TKA) femoral component with an all polyethylene tibia as a functional prosthetic spacer in place of a conventional all cement spacer for the management of periprosthetic joint infection (PJI). The aim of this multicenter study was to retrospectively review (1) ultimate treatment success; (2) reimplantation rates; (3) reoperation rates; and (4) change in knee range of motion in patients managed with functional prosthetic spacers following TKA PJI. METHODS: A retrospective review was performed for patients at 2 tertiary care centers who underwent a functional prosthetic spacer implantation as part of a functional single-stage (n = 57) or all cement spacer conventional two-stage (n = 137) revision arthroplasty protocol over a 5-year period. Outcomes including reinfection, reimplantation, and reoperation rates, success rate as defined by the Delphi criteria, and final range of motion were compared between the 2 cohorts at a minimum of 2-year follow-up. RESULTS: There was no significant difference in reinfection (14.0 vs 24.1%), reoperation (19.3 vs 27.7%), or success rates (78.9 vs 70.8%; P > .05 for all) between the one-stage and two-stage revision TKA cohorts. Mean final total arc of motion was also similar between the 2 groups (105.8 vs 101.8 degrees, respectively). CONCLUSION: Functional prosthetic spacers offer the advantage of a single procedure with decreased overall hospitalization and improved cost-effectiveness with analogous success rates (78.9%) compared with two-stage exchange (70.8%) at mid-term follow-up. Although long-term data are required to determine its longevity and efficacy, the outcomes in this study are encouraging. LEVEL OF EVIDENCE: 3.

Bilateral Femoral Neck Fractures in a Middle-Aged Female After a Low-Energy Fall.

BACKGROUND: Bilateral hip fractures after low-energy mechanism are a rare phenomenon. Most published case reports include presentations of bilateral hip fractures in the elderly with low-energy mechanism. There is no report, to our knowledge, that illustrates this rare occurrence in middle-aged individuals after a low-energy fall from standing height. CASE PRESENTATION: We present a case of a 50-year-old female with history of cerebrovascular accident (CVA) who presented to our institution with bilateral valgus-impacted femoral neck fractures after a mechanical fall from standing height. The patient underwent successful in-situ percutaneous screw placement in bilateral hips. CONCLUSION: Although patient age is an obvious risk factor, middle-aged individuals with a medical history affecting bone mineral content may also be prone to bilateral insufficiency fractures. Individuals complaining of joint pain (with a history of conditions including renal failure, obesity, endocrinopathies, etc.) should have advanced imaging, if screening plain radiographs are negative, in an effort to identify occult fractures.

Tranexamic Acid Reduces Transfusion Rates in Obese Patients Undergoing Total Joint Arthroplasty.

BACKGROUND: While tranexamic acid (TXA) has been well shown to reduce blood loss after joint replacement surgery, little is known regarding its effectiveness in obese patients. The aim of this study was to evaluate the effect of TXA changes in hematocrit and hemoglobin levels as well as incidence of packed red blood cell (pRBC) transfusions in obese patients undergoing total joint arthroplasty (TJA). MATERIAL AND METHODS: Between January 2014 and May 2015, 420 consecutive primary joint replacements were performed by two surgeons at our institution. One-hundred-fifty-seven patients (total hip arthroplasty [THA]=29; total knee arthroplasty [TKA]=128) were obese with a body mass index (BMI) greater than or equal to 30 kg/m2. Medical records were reviewed and identified that TXA was utilized in 85 (54.1%) arthroplasties (study group) and was compared to a consecutive series of 72 (45.9%) TJAs (control group). TXA was given intravenously (IV) in two doses: (1) one gram prior to incision and (2) one gram at the time of femoral preparation in THA or prior to cementation in TKA. Changes in hemoglobin and hematocrit levels, number of pRBC transfusions, and occurrence of thrombolytic events were recorded. RESULTS: The changes in hematocrit (7.2% vs. 8.1%) and hemoglobin levels (3.0 g/dl vs. 3.3 g/dl) were less in the group that received TXA than the control group, albeit not significantly (p=0.100 and p=0.278, respectively). Within the control group, 26 (36.1%) patients required a pRBC transfusion with a mean of 2.0 units per patient (range:1-5); whereas, only eight (9.4%) patients with TXA required a mean of 1.6 units per patient (range: 1-2). The use of TXA significantly reduced the incidence of pRBC transfusions, especially in TKA (p<0.001). Sub-analyses revealed that transfusion rates were even more significantly reduced by TXA in obesity type II and III. Two pulmonary emboli were reported in the group that did not receive TXA; whereas, no thrombolytic events were reported in the group that did receive TXA. CONCLUSION: Utilization of TXA significantly reduced the rate of pRBC transfusions in obese patients.

Are All Periprosthetic Joint Infections the Same? Evaluating Major vs Minor Criteria.

BACKGROUND: The diagnosis of periprosthetic joint infection (PJI) can be made when 1 major criterion or 3 of 5 minor criteria are present. However, the outcomes of patients with a major vs minor criteria for diagnosis have not been studied. The objective of this study was to evaluate if a difference in outcome of surgical intervention existed between patients with PJI who were diagnosed with a major criterion or a combination of minor criteria. METHODS: A retrospective chart review identified 277 primary total hip or knee arthroplasty patients who had developed PJI based on the International Consensus Meeting definition. Patients were further stratified into "major" vs "minor" groups. Patient demographics, PJI workup, surgical treatment, microbiological growth, and clinical outcomes were recorded. Treatment success was defined by using the Delphi criteria. Standard statistical analysis was performed. RESULTS: Overall, 34 patients met minor-only criteria (12.2%), whereas 243 met major criteria. Of the minor-only patients, 16 (47%) were culture negative. When controlling for confounding variables, there was no statistically significant difference with regard to treatment success (minor 94.1% vs major 82.3%, P = .085) between groups at final follow-up (mean 110 months, range 2.3-567 months). Only higher Charlson comorbidity index (P = .001) and an initial 2-stage surgical procedure (P = .003) were associated with decreased treatment success. CONCLUSION: PJI patients were similar between both criteria groups, and there was no difference in treatment success as defined by the Delphi criteria between minor-only PJI and major criteria PJI patients.

Positive Blood Cultures in Periprosthetic Joint Infection Decrease Rate of Treatment Success.

BACKGROUND: Blood cultures are often obtained at the time of periprosthetic joint infection (PJI) diagnosis yet they are not considered part of the diagnostic criteria and the effects of a positive result on surgical outcome are unknown. The purposes of this study are to characterize the use of blood cultures when diagnosing PJI and to determine the association of positive blood cultures with PJI treatment success. METHODS: A retrospective chart review on 320 patients surgically treated for primary hip and knee PJIs was performed from 2006-2013 at 2 academic medical centers with minimum 12-month follow-up. Treatment success was defined by the Delphi criteria. Multiple logistic regression analysis was performed to identify variables associated with treatment success. RESULTS: Blood cultures were obtained from 53.1% of PJI patients (170/320) at the time of diagnosis. The same organism was identified 86.0% of the time in blood culture and operative culture. Patients with positive blood cultures at the time of PJI diagnosis had elevated synovial white blood cell count (98,979, P = .012), elevated serum C-reactive protein (24.2 mg/L, P < .001), and decreased treatment success (65.1%) compared with those with a negative blood culture (85.0%) and those without a blood culture (82.7%, P = .013). A positive blood culture remained associated with decreased PJI treatment success using multiple logistic regression analysis. CONCLUSION: The presence of positive blood cultures at the time of PJI diagnosis decreased PJI treatment success. Further prospective studies are needed to help identify the role of blood cultures in the work up of PJI and treatment optimization in these patients.

Effects of Coronal Limb Alignment and Ligament Balance on Pain and Satisfaction Following Total Knee Arthroplasty at Short-Term Follow Up.

INTRODUCTION: Few studies have evaluated the concomitant effect of both total knee arthroplasty (TKA) limb alignment and ligament laxity. Therefore, the primary aim of this study is to evaluate the impact of lower extremity alignment on the short-term outcome (one year) following TKA, including pain relief, function, and patient satisfaction. The secondary aim of the study is to evaluate the impact of ligament laxity and balance on early outcomes following TKA. MATERIALS AND METHODS: A prospective evaluation of mechanical alignment and ligament tension was performed for 110 consecutive TKAs using an identical surgical technique. Patients were evaluated with knee society score, visual analog pain score, and satisfaction one year following TKA. Linear regression analysis was then performed to determine the effect of lower extremity alignment and ligament laxity. RESULTS: There was no significant relationship between lower extremity alignment and outcome measures. A significant relationship was identified between medial collateral laxity in full extension and knee society scores for function, but not for pain. There was also a significant relationship identified between lateral knee laxity at 90 degrees of flexion and knee society score and pain at one-year follow up. CONCLUSION: Our results demonstrated no correlation between mechanical alignment restoration and pain or function. However, more interestingly, this study found patients with medial laxity in extension and lateral laxity in knee flexion, similar to normal physiologic knee laxity, to have less pain and greater function and satisfaction at one-year short-term follow up.

Cost Savings in a Surgeon-Directed BPCI Program for Total Joint Arthroplasty.

BACKGROUND: There are few studies available on the savings generated and strategies employed for cost reduction in total joint arthroplasty. In this study, our organization-a group of private practices partnering with a consultant-aimed to analyze the impact of a preoperative protocol on overall cost savings. MATERIALS AND METHODS: Using administrative data from the Medicare Bundled Payments for Care Improvement (BPCI) initiative, 771 consecutive total joint arthroplasty patients from 2009-2014 were compared with 408 consecutive BPCI patients from 2014-2017. The 30-day episode and Medicare part B total cost of care was analyzed. This included inpatient and post-discharge expenditure, laboratory and imaging costs, physician and ER visits, and readmission. RESULTS: Average total episode cost declined by $3,174 or 13% from $23,925 to $20,752 (p<0.001) in the BPCI period. Readmission rate was unchanged (p=0.20), and there was a 48% reduction in the percent of patients presenting to the emergency room (p=.03). There was a decline of $2,647 (78%) in skilled nursing cost per case, which represented the majority of savings. Post-discharge imaging, laboratory test claims, postoperative emergency room visits, primary care physician (PCP) visits, and cost per episode all decreased. The decrease in PCP utilization did not result in increased medical complications or readmissions. CONCLUSION: Our preoperative patient-education protocol has decreased non-home discharge, unnecessary postoperative physician visits, and diagnostic testing resulting in an episode cost savings of 13%. With Advanced BPCI on the horizon, orthopedic surgeon control as the awardee of the bundle, combined with an increasing focus on patient education, will continue to lower costs and improve patient care.

Articulating Spacers as a Modified One-Stage Revision Total Knee Arthroplasty: A Preliminary Analysis.

INTRODUCTION: Periprosthetic joint infection (PJI) following primary total knee arthroplasty (TKA) is a challenging complication for surgeons and patients alike. Although two-stage revision arthroplasty remains the gold standard PJI management in the United States, one-stage revision has had success in many parts of Europe. The aim of this study was to retrospectively review: 1) ultimate treatment success; 2) necessary antibiotic duration; 3) change in knee range of motion (ROM); and 4) final Knee Society Scores (KSS) in a case series of patients managed with retention of articulating antibiotic spacers following PJI. MATERIALS AND METHODS: A retrospective review was performed on all patients treated for chronic PJI after primary TKA with retention of articulating antibiotic spacers at a minimum of one-year follow-up. Descriptive analysis was utilized to evaluate demographic characteristics, discharge destination, follow-up and antibiotic durations, Knee Society Score (KSS), and rates of treatment failure. Paired-Samples t-Tests were utilized to evaluate mean changes in flexion and extension between the preoperative and postoperative time periods. RESULTS: Our final cohort included 29 patients who were managed with articulating spacer retention at a mean follow-up of 16.8 (range, 12.0 to 23.1) months, with 21 patients (72.4%) medically unfit for multiple surgeons and eight patients (27.6%) satisfied with their function. Mean age was 61.3 (range, 41 to 85) years and mean Charlson Comorbidity Index (CCI) was 6.1 (mean, 0 to 12). The predominant infecting organism was Methicillin-Resistant Staphylococcus aureus (MRSA), which was involved in eight patients (27.6%). There was a significant increase in postoperative knee flexion (+14.7°; p<0.001) and no decrease in postoperative knee extension (+2.3°; p=0.361). Treatment success in our cohort was 79.3% (23 patients), with four patients (13.8%) having chronic wound drainage and two patients (6.9%) requiring multiple spacer exchanges. Sixteen patients (55.2%) were able to complete their antibiotic regimen, with the remaining patients unable to discontinue their antibiotics by latest clinic follow-up. DISCUSSION: One-stage exchange arthroplasty offers the advantage of a single procedure with analogous failure rates compared to two-stage exchange, decreases hospitalization, and improves cost-effectiveness, which is paramount in today's healthcare environment. To our knowledge, this is the first study in the United States to evaluate outcome scores, function, and success rate of a modified one-stage revision TKA technique. Although we are unable to make definitive conclusions based on the small sample size, the outcomes in this study are encouraging.

Effect of Bundled Payments and Health Care Reform as Alternative Payment Models in Total Joint Arthroplasty: A Clinical Review.

BACKGROUND: In an effort to control rising healthcare costs, healthcare reforms have developed initiatives to evaluate the efficacy of alternative payment models (APMs) for Medicare reimbursements. The Center for Medicare and Medicaid Services Innovation Center (CMMSIC) introduced the voluntary Bundled Payments for Care Improvement (BPCI) model experiment as a means to curtail Medicare cost by allotting a fixed payment for an episode of care. The purpose of this review is to (1) summarize the preliminary clinical results of the BPCI and (2) discuss how it has led to other healthcare reforms and alternative payment models. METHODS: A literature search was performed using PubMed and the CMMSIC to explore different APMs and clinical results after implementation. All studies that were not in English or unrelated to the topic were excluded. RESULTS: Preliminary results of bundled payment models have shown reduced costs in total joint arthroplasty largely by reducing hospital length of stay, decreasing readmission rates, as well as reducing the number of patients sent to in-patient rehabilitation facilities. In order to refine episode of care bundles, CMMSIC has also developed other initiatives such as the Comprehensive Care for Joint Replacement (CJR) pathway and Surgical Hip and Femur Fracture (SHFFT). CONCLUSION: Despite the unknown future of the Affordable Care Act, BPCI, and CJR, preliminary results of alternative models have shown promise to reduce costs and improve quality of care. Moving into the future, surgeon control of the BPCI and CJR bundle should be investigated to further improve patient care and maximize financial compensation.