Faculty Bibliography

BACKGROUND:There are a variety of methods available to treat periprosthetic joint infection (PJI), including 2-stage revision with the use of an antibiotic spacer. This study compares the outcomes of real-component (RC) and all-cement (AC) articulating spacers for total hip arthroplasty (THA) PJI treatment. METHODS:This multicenter retrospective study assessed all articulating spacers placed for THA PJI between April 2011 and August 2020. Patients were dichotomized based on spacer type (RC vs AC). RESULTS:One hundred four patients received articulating spacer constructs (RC group = 75, AC group = 29). Leg-length discrepancy was significantly greater in the AC group after the second stage (3.58 vs 12.00 mm, P = .023). There were no significant differences in reoperation rates following first-stage spacer placement (P = .752) and time to reimplantation (P = .127) between the groups. There were no significant differences in reinfection rates (RC group = 10.0%, AC group = 7.1%, P = 1.000) and reoperation rates following second-stage revision THA (RC group = 11.7%, AC group = 10.7%, P = 1.000). Hospital length of stay (in days) had a trend toward being shorter following the first (7.35 vs 11.96, P = .166) and second stage (3.95 vs 5.43, P = .107) for patients in the RC group. Patients in the RC group were more likely to be discharged home following the first (P = .020) and second (P = .039) stages. CONCLUSION/CONCLUSIONS:Given that there were no differences in reinfection and reoperation rates between the 2 spacer constructs, RC articulating spacers may provide a significant benefit for patient comfort during 2-stage exchange treatment of PJI while adding no increase in risk profile.

Venous thromboembolism (VTE) is a rare, but serious complication following total knee arthroplasty (TKA). Current VTE guidelines recommend pharmacologic agents with or without intermittent pneumatic compression devices (IPCDs). At our institution, both 81-mg aspirin (ASA) twice a day (BID) and portable IPCDs were previously prescribed to TKA patients at standard risk for VTE, but the IPCDs were discontinued and patients were treated with ASA alone going forward. The aim of this study is to determine if discontinued use of outpatient IPCDs is safe and does not increase the rate of VTE or any other related complications in patients following TKA. A retrospective review of 2,219 consecutive TKA cases was conducted, identifying patients with VTE, bleeding complications, infection, and mortality within 90 days postoperatively. Patients were divided into two cohorts. Patients in cohort one received outpatient IPCDs for a period of 14 days (control), while those in cohort two did not (ASA alone). All study patients received inpatient IPCDs and were maintained on 81-mg ASA BID for 28 days. A posthoc power analysis was performed using a noninferiority margin of 0.25 (α = 0.05; power = 80%), which showed that our sample size was fully powered for noninferiority for our reported deep vein thrombosis (DVT) rates, but not for pulmonary embolism (PE) rates. A total of 867 controls and 1,352 patients treated with ASA alone were identified. Only two control patients were diagnosed with a PE (0.23%), while one patient in the ASA alone group had DVT (0.07%). There was no statistical difference between these rates (p = 0.33). Furthermore, no differences were found in bleeding complications (p = 0.12), infection (p = 0.97), or 90-day mortality rates (p = 0.42) between both groups. The discontinued use of outpatient portable IPCDs is noninferior to outpatient IPCD use for DVT prophylaxis. Our findings suggest that this protocol change may be safe and does not increase the rate of VTE in standard risk patients undergoing TKA while using 81-mg ASA BID.

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/METHODS:III.

BACKGROUND:Targets of acetabular inclination and anteversion have been suggested based on a patient's spinopelvic mobility. Current methods in total hip arthroplasty (THA) include manual instrumentation, computer-assisted navigation, and robotic-assisted surgery. This study aims to compare the accuracy of these 3 methods in targeting the functional safe zone. METHODS:This is a prospective multicenter study including a series of 251 consecutive primary posterior THA patients from April 2019 to January 2021. Preoperative lateral standing and sitting spinopelvic radiographs were obtained. Each patient was classified using the Hip-Spine Classification. A functional safe zone plan was determined. Surgeons used their preferred method (manual instrumentation, computer-assisted, or robotic-assisted). Postoperative anteversion and inclination was measured and compared to the preoperative plan. Mean differences between preoperative and postoperative values were calculated. Welch's t-test was used to assess significant between-group differences with P < .05 considered significant. RESULTS:Of the 249 patients, there were 63 manual instrumentation, 68 computer-assisted navigation, and 118 robotic-assisted surgery. Robotic-assisted surgery (rTHA) was significantly more accurate in targeting anteversion (1 ± 2) compared to manual instrumentation (mTHA; 7 ± 6, P < .001) and computer-assisted navigation (cTHA; 6 ± 6, P < .001). rTHA was also significantly more accurate in targeting inclination (1 ± 1) compared to mTHA (8 ± 7, P < .001) and cTHA (6 ± 7, P < .001). Although cTHA had greater accuracy in targeting both inclination and anteversion compared to mTHA, these differences were not statistically significant. CONCLUSION/CONCLUSIONS:Robotic-assisted surgery was more accurate than both computer-assisted navigation and manual instrumentation in targeting the functional safe zone in primary THA. Further research is needed to evaluate the effect of improved accuracy on dislocation rates.

AIMS/OBJECTIVE:Although readmission has historically been of primary interest, emergency department (ED) visits are increasingly a point of focus and can serve as a potentially unnecessary gateway to readmission. This study aims to analyze the difference between primary and revision total joint arthroplasty (TJA) cases in terms of the rate and reasons associated with 90-day ED visits. METHODS:We retrospectively reviewed all patients who underwent TJA from 2011 to 2021 at a single, large, tertiary urban institution. Patients were separated into two cohorts based on whether they underwent primary or revision TJA (rTJA). Outcomes of interest included ED visit within 90-days of surgery, as well as reasons for ED visit and readmission rate. Multivariable logistic regressions were performed to compare the two groups while accounting for all statistically significant demographic variables. RESULTS:Overall, 28,033 patients were included, of whom 24,930 (89%) underwent primary and 3,103 (11%) underwent rTJA. The overall rate of 90-day ED visits was significantly lower for patients who underwent primary TJA in comparison to those who underwent rTJA (3.9% vs 7.0%; p < 0.001). Among those who presented to the ED, the readmission rate was statistically lower for patients who underwent primary TJA compared to rTJA (23.5% vs 32.1%; p < 0.001). CONCLUSION/CONCLUSIONS: 2022;3(7):543-548.

BACKGROUND:Although several techniques and implants have been developed to address bone loss in revision total knee arthroplasty (rTKA), management of these defects remains challenging. This review article discusses the indications and management options of bone loss following total knee arthroplasty based on preoperative workup and intraoperative findings. MAIN TEXT/METHODS:Various imaging modalities are available that can be augmented with intraoperative examination to provide a clear classification of a bony defect. For this reason, the Anderson Orthopaedic Research Institute (AORI) classification is frequently used to guide treatment. The AORI provides a reliable system by which surgeons can classify lesions based on their size and involvement of surrounding structures. AORI type I defects are managed with cement with or without screws as well as impaction bone grafting. For AORI type IIA lesions, wedge or block augmentation is available. For large defects encompassing AORI type IIB and type III defects, bulk allografts, cones, sleeves, and megaprostheses can be used in conjunction with intramedullary stems. CONCLUSIONS:Treatment of bone loss in rTKA continues to evolve as different techniques and approaches have been validated through short- and mid-term follow-up. Extensive preoperative planning with imaging, accurate intraoperative evaluation of the bone loss, and comprehensive understanding of all the implant options available for the bone loss are paramount to success.

INTRODUCTION/BACKGROUND:Surgeons can improve their practice by understanding potentially avoidable reasons for early revision total knee arthroplasty (rTKA). The purpose of this study is to describe potentially avoidable indications for rTKA within 5 years of the index procedure. METHODS:This retrospective observational analysis utilized the rTKA database at a large, academic orthopedic specialty hospital to identify 167 consecutive rTKA from 2014 to 2019 performed within 5 years after primary TKA (pTKA). Two fellowship-trained arthroplasty surgeons reviewed the cases to classify them as potentially avoidable or unavoidable. Unavoidable indications for rTKA included infection/wound complication, arthrofibrosis, instability due to underlying collagen disease or significant weight loss, and any traumatic event leading to pTKA failure. Potentially avoidable indications included atraumatic instability, intraoperative fracture, metal allergy, and atraumatic patellar instability or maltracking. Aseptic loosening was considered avoidable if it occurred in the presence of component malpositioning or poor cementation technique. RESULTS:There were 112 (67.1%) unavoidable cases and 55 avoidable cases (32.9%). Of the unavoidable cases, there were 68 rTKA for infection or wound complications (60.7%), 23 for arthrofibrosis (20.5%), 6 for instability (5.4%), 6 for postoperative fracture (5.4%), 6 for aseptic loosening (5.4%), and 3 for extensor mechanism pathology following trauma (2.6%). Of the potentially avoidable rTKA, 24 were for aseptic loosening (43.7%), 23 for atraumatic instability (41.8%), 6 for atraumatic extensor mechanism pathology (10.9%), 1 for nickel allergy (1.8%), and 1 for intraoperative fracture (1.8%). CONCLUSION/CONCLUSIONS:These findings indicate that over 30% of early rTKA are potentially avoidable. Interventions should focus on addressing potentially avoidable causes such as short-term aseptic loosening and instability to reduce the need for costly and resource-intensive rTKA. Level of evidence III, retrospective observational analysis.

INTRODUCTION/BACKGROUND:The purpose of this study was to identify common complications and the rates of readmission and revision in total knee arthroplasty (TKA) patients younger than 65 years. METHODS:Using the American Joint Replacement Registry, we conducted a retrospective review of all TKAs done in patients aged 18 to 65 years from 2012 to 2020. Demographic factors such as age, sex, Charlson Comorbidity Index (CCI), and preoperative Veterans RAND 12-Item Health Survey Physical Component Summary (VR-12 PCS) scores were collected. We excluded patients older than 65 years and revision, oncologic, and nonelective cases. Primary outcomes included cumulative revision rate, 90-day readmission rate, and reason for revision. Univariate analysis and the Kaplan-Meier method were used. RESULTS:Six thousand one hundred seventy-nine patients were included. The average age was 58.8 years (SD 5.5 years), 61% were female, 82% were White, and 88% had a CCI of 0 (1 = 8% and ≥2 = 4%). The mean follow-up was 42.51 months. Seventy-four patients (1.2%) underwent revision. Sixty-nine patients (1.1%) were readmitted within 90 days. No factors assessed increased revision rates. Revision-free survivorship was 98.7% (95% CI 98.4 to 99.0) and 98.6% (95% CI 98.2 to 99.0) at 5 and 8 years, respectively. Infection (15%), aseptic loosening (14%), and instability (12%) were the most common indications for revision. CONCLUSION/CONCLUSIONS:TKA done in young and presumed active patients has excellent survivorship. Long-term follow-up is needed to assess survival trends in this growing population.

INTRODUCTION/BACKGROUND:Airborne biologic particles (ABPs) can be measured intraoperatively to evaluate operating room (OR) sterility. Particulate matter (PM) up to 2.5 microns can contain microbial species which may increase infection risk. Our study examines differences in air quality and ABP count in primary (pTKA) and revision total knee arthroplasty (rTKA). METHODS:We analyzed primary and revision TKAs in a single operating room at an academic institution from January 2020 to December 2020. Procedures from March 15, 2020-May 4, 2020 were excluded to avoid COVID-related confounding. Temperature, humidity, and ABP count per minute were recorded with a particle counter intraoperatively and cross-referenced with surgical data from the electronic health records (EHR) using procedure start and end times. Descriptive statistics were used to evaluate differences in variables. P-values were calculated using t-test and chi-square. RESULTS:A total of 107 TKA cases were included: 79(73.8%) pTKAs and 28(26.2%) rTKAs. Time spent in room was significantly higher for rTKAs (primary: 176+46.7 minutes vs. revision: 220+47.1,p<0.0001). Compared to pTKAs, rTKAs had significant percent increases in ABP rates for particles measuring 0.3um(+70.4%,p<0.001), 0.5um(+97.2%,p<0.0001), 1.0um(+53.2%,p=0.001), 2.5um(+30.3%,p=0.017), and for PM 2.5(+108.3%,p<0.001) and PM5.0(+105.6%,p<0.001). CONCLUSION/CONCLUSIONS:RTKAs had significantly longer time spent in room and significant percent increases in ABP rates for particles measuring 0.3um, 0.5um, and 1.0um compared to pTKAs. Measurements of PM2.5 and PM5.0 (which can contain large numbers of microbes) were also significantly greater in rTKAs. Further research is needed to determine whether the size and quantity of ABPs translates to higher infection rates following rTKA.

INTRODUCTION/BACKGROUND:Traditionally, most efforts have focused on readmission rates while little has been reported on emergency department (ED) presentation. This study aims to analyze the difference between same-day discharge (SDD) and non-SDD primary total hip and knee arthroplasty (THA and TKA) cases to determine the rate and reasons associated with 90-day ED presentations. METHODS:We retrospectively reviewed all patients who underwent primary THA and TKA between 2011-2021. The patients were separated into two cohorts: 1.)SDD;2.)required a longer length-of-stay(LOS). The primary outcome was an ED visit within 90-days of the index operation. Secondary outcomes included reasons for ED visits and readmission rates. Multivariable logistic regressions were performed to compare the two groups while accounting for significant demographic variables. RESULTS:Of the 24,933 patients included, 1,725(7%) were SDD and 23,208(93%) required a longer LOS. The overall rate of 90-day ED visits was significantly lower for patients who were SDD compared to non-SDD (1.6%vs.4.0%,p=0.004). However, when stratified based on the reason for ED visit, no single cause was significant between the two cohorts. The most commonly reported reasons were pain (32.1%vs.26.7%,p=0.064) and other non-orthopedic related medical issues (25.0%vs.29.5%,p=0.206). Among those who presented to the ED, the readmission rate did not statistically differ (25.0%vs.23.4%,p=0.131). CONCLUSION/CONCLUSIONS:Patients that underwent SDD were less likely to present to the ED within 90-days following their surgery compared to non-SDD. Approximately three-fourths of the patients in both cohorts that visited the ED did not require readmission. Future efforts should focus on developing interventions to reduce the burden of these visits on the healthcare system.