Faculty Bibliography

INTRODUCTION/UNASSIGNED:Advanced age is considered a major risk factor for postoperative complications in total hip arthroplasty (THA). Consequently, older patients undergoing THA may require more detailed pre-procedural examinations and more healthcare resources postoperatively than younger patients. The purpose of this study was to compare discharge parameters and complication rates of THA in patients ⩾90 years old to those <90 years old. METHODS/UNASSIGNED:-tests. RESULTS/UNASSIGNED:= 1.000). CONCLUSIONS/UNASSIGNED:Although THA patients over 90 years of age had a longer LOS and differing discharge disposition, these patients had similar complications compared to their younger counterparts. Thus, our study supports similar efficacy of THA in patients 90 years and older relative to younger THA candidates.

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: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.

BACKGROUND:Image-guided joint aspirations used to assist the diagnosis of periprosthetic joint infection (PJI) may commonly result in a dry tap-or insufficient fluid for culture and cell count analysis. Dry tap aspirations are painful and invasive for patients and often utilize a subsequent saline lavage to obtain a microbiology sample. Currently, there is a paucity of the literature addressing predictors that could suggest whether a dry tap will occur. The purpose of this study was to examine the effects of various factors on "dry tap" occurrence in patients with suspected PJI following total hip arthroplasty (THA). METHODS:A retrospective review was performed among THA patients suspected for PJI who received image-guided joint aspiration procedures at our institution from May 2016 to February 2020. The procedural factors included the imaging modality used for aspiration, anatomic approach, needle gauge size used, and the presence of a trainee. The patient-specific factors included number of prior ipsilateral hip surgeries, femoral head size, ESR/CRP values, and BMI. RESULTS:In total, 336 patients met our inclusion criteria. One hundred and twenty hip aspirations resulted in a dry tap (35.7%) where the patients underwent a saline lavage. Among the procedural and patient-specific factors, none of the factors were found to be statistically different between the two cohorts nor conferred any greater odds of a dry tap occurring. CONCLUSION/CONCLUSIONS:No associations with dry tap occurrence were found among the procedural and patient-specific factors studied. Further research is needed to identify additional factors that may be more predictive of dry taps.

INTRODUCTION/BACKGROUND:Although tourniquet use in primary total knee arthroplasty (TKA) has been widely studied, the outcomes associated with tourniquet use in revision TKA (rTKA) remains relatively unexplored. This study investigates surgical outcomes and patient satisfaction in association with tourniquet use during aseptic rTKA. METHODS:We retrospectively reviewed all patients who underwent rTKA for aseptic causes at our institution from 2011-2020. Patients were separated into two cohorts based on tourniquet inflation during the procedure. Outcomes of interest included estimated blood loss (EBL), change in hemoglobin (Hb), surgical time, length-of-stay (LOS), reoperation rate, and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS,JR) scores. RESULTS:Of the 1,212 patients included, 1,007 (83%) underwent aseptic rTKA with the use of a tourniquet and 205 (17%) without the use of a tourniquet. The mean tourniquet inflation time was 93.0 minutes (SD:33.3 minutes). Blood loss was significantly less for patients in the tourniquet cohort as measured through EBL(224.1vs.325.1 mL,p<0.001) and change in preoperative to postoperative Hb(1.75vs.2.04 g/dL,p<0.001). There were no statistical differences in surgical time(p=0.267) and LOS(p=0.206) between the two groups. The reoperation rate was significantly greater for patients who did not have a tourniquet utilized (20.5%vs.15.0%,p=0.038). Delta improvement in KOOS,JR scores from baseline to 3-months postoperatively did not statistically differ between the two cohorts (p=0.560). CONCLUSION/CONCLUSIONS:While delta improvements in KOOS,JR scores were similar for both cohorts, patients who did not have a tourniquet inflated during aseptic rTKA had increased blood loss and were more likely to undergo subsequent reoperation compared to patients who did.

BACKGROUND:Obesity is a recognized risk factor for severe knee osteoarthritis. However, it remains unclear how obesity prevalence trends in the current population undergoing total knee arthroplasty (TKA) compare with those seen in individuals not undergoing this procedure. In this study, we assessed the yearly trends in body mass index (BMI) and obesity rates between patients who have undergone primary TKA and those in the general population. METHODS:We retrospectively reviewed all patients ≥18 years of age from January 2013 through December 2020 who underwent primary, elective TKA and those who had an annual routine physical examination at our institution within the same period. Baseline demographic characteristics were collected. The independent samples t test was used to compare means and the chi-square test was used to compare proportions between the 2 cohorts, and a linear regression was used to determine the significance of the yearly trends. RESULTS:A total of 11,333 patients who underwent primary TKA and 1,158,168 patients who underwent an annual physical examination were included in this study. After adjusting for age, we found the mean BMI for the TKA group to be significantly greater (p < 0.001) every year compared with the annual physicals group. The proportion of patients who were categorized into any obesity class (BMI, ≥30 kg/m2), Class-I obesity (BMI, 30 to 34.9 kg/m2), Class-II obesity (BMI, 35 to 39.9 kg/m2), and Class-III obesity (BMI, ≥40 kg/m2) was significantly higher for the TKA group each year compared with the annual physicals group. An analysis of trends over time showed a significantly increasing trend (p < 0.001) in BMI and obesity rates for the annual physicals group, but a stable trend for patients undergoing TKA. CONCLUSIONS:Patients who underwent TKA continued to have higher BMI than the general population, which showed a steady increase over time. Physicians need to continue in their efforts to educate patients on weight management and healthy lifestyles to potentially delay the need for a surgical procedure. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

INTRODUCTION/BACKGROUND:The purpose of this study is to report on the association between the number of stairs to enter home and length of stay (LOS), discharge disposition, and patient reported outcome measures (PROMs) among patients who underwent primary total joint arthroplasty (TJA). MATERIALS AND METHODS/METHODS:We retrospectively reviewed patients who underwent primary total hip or knee arthroplasty between January 2016 and March 2020. Only patients with documentation of the number of stairs to enter their homes were included in the study. The two cohorts were separated into four groups: none, 1-10, 11-20, and > 20 stairs. Collected variables included demographic data, LOS, discharge disposition, and PROMs. Chi-square and ANOVA were utilized to determine significance. RESULTS:Of the 1116 patients included, 510 underwent THA, and 606 underwent TKA. There was no statistical difference in LOS (THA: p = 0.308; TKA: p = 0.701) and discharge disposition (THA: p = 0.371; TKA: p = 0.484) in both cohorts regardless the number of stairs. There was no statistical difference in FJS-12 scores at 3 months (THA: p = 0.590; TKA: p = 0.206), 12 months (THA: p = 0.217; TKA: p = 0.845), and 21 months (THA: p = 0.782; TKA: p = 0.296) postoperatively for both cohorts. There was no statistical difference in HOOS, JR scores preoperatively (p = 0.278) and at 3 months postoperatively (p = 0.527) for the THA cohort, as well as KOOS, JR scores preoperatively and at 3 and 12 months postoperatively (p = 0.557; p = 0.522; p = 0.747) for the TKA cohort. CONCLUSION/CONCLUSIONS:We found no statistical differences in LOS, discharge disposition, and PROMs in patients who underwent TJA, irrespective of the number of stairs negotiated to enter their home. These findings can aid surgeons to provide preoperative education and reassurance to patients who have concerns with their discharge planning due to the walk-up stairway at their residence.

BACKGROUND:The purpose of this study is to determine if the number and types of patient-reported drug allergies are associated with prosthetic joint infection (PJI) and functional outcomes following total joint arthroplasty (TJA). METHODS:This is a retrospective review of all patients who underwent a primary, elective total hip (THA) or knee arthroplasty (TKA) over a 10-year period at a single academic institution. Demographic, clinical information, and number and type of patient-reported drug allergy was collected. Univariate and multivariate logistic regressions were performed to identify risk factors for PJI and risk of PJI based on number of allergies. Univariate analysis was also performed to identify if the number of patient-reported allergies affected functional outcome scores. RESULTS:Of 31,109 patients analyzed, there were 941 (3%) revisions for infection (491 knees and 450 hips). At least one allergy was reported by 16,435 (52.8%) patients, with a mean of 1.2 ± 1.9. Those who underwent revision for infection had a significantly higher number of reported allergies (1.68 ± 1.9 vs 1.23 ± 1.9, P < .0005, 95% confidence interval -0.58 to 0.33). On univariate regression the number of allergies independently predicted revision TJA for infection (P < .0001) as did age, gender, body mass index, and smoking status. On multivariate regression for each additional patient-reported allergy, risk of PJI increased by 1.11 times (95% confidence interval 1.07-1.14, P < .0001). Number of patient-reported allergies did not predict 3-month or 1-year functional outcome scores. CONCLUSION/CONCLUSIONS:Patients with a higher number of reported allergies may be at increased risk of PJI following TJA. LEVEL OF EVIDENCE/METHODS:Prognostic Level II.