Faculty Bibliography

INTRODUCTION/BACKGROUND:Computer-assisted navigation systems (CAS) are increasingly being integrated into total knee arthroplasty (TKA) procedures, but perceptions of associated learning curve and increased operative time continue to curtail uptake. Newer-generation navigational systems aim to streamline integration into surgical workflow to mitigate increases in operative time. Here, we assess the impact of a novel imageless CAS on operative time for TKA. METHODS:A retrospective analysis of prospectively collected data of a cohort of patients undergoing primary unilateral TKA with one of three surgeons between October 2019 and March 2020 was conducted. Consecutive cases using a novel imageless CAS were included in analysis. For each surgeon, average operative time was recorded and compared in sequential five-case cohorts to average operative time for the same procedure performed conventionally using a two-tailed t test. RESULTS:Average conventional operative times were 95.9 ± 15.0, 86.6 ± 13.7, and 116.9 ± 25.1 min for the three surgeons. Initial CAS-assisted operative times increased to 107.0 ± 9.8 (p = 0.07) and 102.4 ± 13.2 (p = 0.06) min for Surgeons 1 and 2 and decreased to 113.2 ± 9.8 min (p = 0.52) for Surgeon 3. Most recent CAS-assisted operative times were 94.8 ± 13.9 (p = 0.88), 88.7 ± 15.3 (p = 0.84), and 104.8 ± 13.2 (p = 0.12) min as compared to pre-CAS. Absolute differences for the most recent navigated procedures ranged from 12.1 min faster to 2.0 min slower. CONCLUSION/CONCLUSIONS:The learning curve for TKA navigation may be as few as 10 cases, and any associated increases in operative time may be transient and non-significant. Moreover, navigation may ultimately speed operative time, perhaps as the result of enhanced intraoperative assessment of alignment.

INTRODUCTION/BACKGROUND:Same-day discharge (SDD) total joint arthroplasty (TJA) programs often have stringent selection criteria. Some patients deemed ineligible may nonetheless be discharged the day of surgery. This study compares outcomes between patients enrolled in our SDD TJA program who were SDD to those who did not participate in the program but were also SDD. METHODS:We retrospectively reviewed all patients who were SDD following TJA from 2015-2020. Patients were stratified into two cohorts based on whether they were formally enrolled in our institution's SDD TJA program. Propensity-score matching was performed to limit confounding and independent sample t-tests or Pearson's chi-squared tests were used to compare outcomes of interest between the matched groups. RESULTS:Of the 1,778 patients included, 1,384(78%) completed the SDD TJA program and 394(22%) were SDD but did not participate in the SDD TJA program. Upon 1:1 propensity-score matching, a total of 550 patients were matched for comparison. Surgical time was significantly longer for patients who did not participate in the SDD TJA program compared to those who participated in the program (109.39vs.87.29 minutes; p<0.001). Discharge disposition(p=0.999), 90-day ED-visit (p=0.476), 90-day all-cause readmissions(p=0.999), 90-day all-cause revisions(p=0.563), as well as HOOS,JR and KOOS,JR scores at all time-points did not significantly differ. CONCLUSION/CONCLUSIONS:Enrollment in a formal SDD TJA program may not be a necessary precursor to achieving similar outcomes following TJA for patients that are SDD without formally enrolling. Therefore, a formal program may no longer be needed at an institution with well-established evidence-based protocols with strong success and experience with value-based care.

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.

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.

Aseptic loosening is a common cause of revision total hip arthroplasty (rTHA) and with the rising number of primary THAs, revisions for aseptic loosening represent a significant burden for arthroplasty surgeons. Aseptic loosening remains a diagnostic and management challenge. Loosening can occur as a result of inadequate initial fixation, mechanical loss of fixation over time or a biologic loss of fixation over time. However, in most cases, etiology is multifactorial involving all three factors. The diagnosis of aseptic loosening involves a careful history, focused clinical exam and thorough evaluation of imaging using several diagnostic modalities. The careful evaluation of serial radiographs remains the cornerstone of diagnosis with additional input from advanced imaging modalities such as FDG-PET, DEXA, MRI and several others, each offering unique advantages and disadvantages. In certain patients, history and physical exam might be the only initial obvious signs of loosening and thus unexplained continuous pain augmented by imaging findings serve as an indication for revision surgery.

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.

INTRODUCTION/BACKGROUND:Although technology-assisted total hip arthroplasty (TA-THA) may improve implant positioning, it remains unknown whether TA-THA confers improved clinical outcomes. We sought to examine national TA-THA utilization trends and compare clinical outcomes between TA-THA and unassisted THA (U-THA). METHODS:Patients who underwent primary, elective THA from 2010 to 2018 were identified using the American College of Surgeons National Surgical Quality Improvement Program database. Demographic, perioperative, and 30-day outcomes were queried and collected. Patients were stratified based on whether they underwent TA-THA, which included computer navigation or robotics, and U-THA. Propensity score matching paired patients undergoing TA-THA or U-THA on a 1:1 basis. RESULTS:Of the 238,755 THA patients, 3,149 cases (1.3%) were done using TA-THA. Comparing the unmatched TA-THA and U-THA groups, race distribution (P < 0.001) and baseline functional status (P < 0.001) differed. Propensity score matching yielded 2,335 TA-THA and U-THA pairs. Perioperatively, the TA-THA cohort had longer mean surgical times (101.0 ± 34.0 versus 91.9 ± 38.8 minutes, P < 0.001), but lower transfusion rates (5.7% versus 7.8%, P = 0.005). As compared with the U-THA group, the TA-THA group had a shorter mean hospital length of stay (2.0 ± 1.1 versus 2.5 ± 2.0 days, P < 0.001) and a higher proportion of patients discharged home (85.8% versus 75.7%, P < 0.001). Notably, the TA-THA cohort had higher readmission rates (3.8% versus 2.4%, P < 0.001). Major complication and revision surgery rates did not markedly differ between groups. DISCUSSION/CONCLUSIONS:TA-THA utilization rates remain low among orthopaedic surgeons. As compared with U-THA, TA-THA yield mixed perioperative and 30-day outcomes. Surgeons must consider the clinical benefits and drawbacks of TA-THA when determining the proper surgical technique and technology for each patient. Clinical trials assessing long-term functional and clinical outcomes between U-THA and TA-THA are required to further elucidate the utility of assistive technologies in THA. LEVEL III EVIDENCE/UNASSIGNED:Retrospective Cohort Study.

INTRODUCTION/BACKGROUND:Periprosthetic joint infection (PJI) after total hip arthroplasty (THA) is challenging to diagnose. We aimed to evaluate the impact of dry taps requiring saline lavage during preoperative intraarticular hip aspiration on the accuracy of diagnosing PJI before revision surgery. METHODS:A retrospective review was conducted for THA patients with suspected PJI who received an image-guided hip aspiration from May 2016 to February 2020. Musculoskeletal Infection Society (MSIS) diagnostic criteria for PJI were compared between patients who had dry tap (DT) versus successful tap (ST). Sensitivity and specificity of synovial markers were compared between the DT and ST groups. Concordance between preoperative and intraoperative cultures was determined for the two groups. RESULTS:In total, 335 THA patients met inclusion criteria. A greater proportion of patients in the ST group met MSIS criteria preoperatively (30.2%vs.8.3%, p<0.001). Patients in the ST group had higher rates of revision for PJI (28.4%vs.17.5%, p=0.026) and for any indication (48.4%vs.36.7%, p=0.039). MSIS synovial WBC count thresholds were more sensitive in the ST group (90.0%vs.66.7%). There was no difference in culture concordance (67.9%vs.65.9%,p=0.709), though the DT group had a higher rate of negative preoperative cultures followed by positive intraoperative cultures (85.7%vs.41.1%, p=0.047). CONCLUSION/CONCLUSIONS:Our results indicate that approximately one-third of patients have dry hip aspiration, and in these patients cultures are less predictive of intraoperative findings. This suggests that surgeons considering potential PJI after THA should apply extra scrutiny when interpreting negative results in patients who require saline lavage for hip joint aspiration.

INTRODUCTION:Posterior cruciate ligament (PCL) retention may impact a patient's awareness of their artificial joint following primary total knee arthroplasty (pTKA) due to increased proprioception and more native knee kinematics. Therefore, the purpose of this study was to investigate whether cruciate-retaining (CR) or posterior-stabilized (PS) implants influence the Forgotten Joint Score (FJS-12) following pTKA. METHODS:We retrospectively reviewed all patients who underwent pTKA with a CR or PS implant at our institute between October 2017 and March 2021. Of the 6,258 patients identified, 5,587 did not have recorded FJS-12 scores at either three months, one year, or two years postoperatively nor a Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) preoperatively, three months, or one year postoperatively, and these were considered lost to follow up. Thus, a total of 671 cases were identified and subsequently stratified into two cohorts based on whether they received a CR (n=236, 35%) or PS (n=435, 65%) implant. Patients who received PS implants were further divided into constrained (CoN) and non-constrained (NCoN) liner cohorts. Multivariable linear regression analysis was used to compare patient-reported outcome (PRO) scores. RESULTS:There were no significant differences in PRO scores between CR and PS implants at any time point. Patients in the CoN (n=74) cohort had significantly higher FJS-12 scores at one year (CoN: 56.31 + 25.34 vs NCoN: 42.24 + 27.00, p=0.001) and two years (CoN: 58.52 + 33.71 vs NCoN: 46.97 + 27.44, p=0.013) postoperatively compared to patients in the NCoN (n=361) cohort. CONCLUSION:Although our analysis demonstrated significant differences in FJS-12 scores at one and two years postoperatively depending upon the liner constraint, there were no significant differences in FJS-12 scores between CR and PS implants. Therefore, while retention of the PCL does not impact patient awareness of their artificial joint, the level of liner constraint may influence outcomes if the PCL is sacrificed.