Faculty Bibliography

BACKGROUND:The incidence of transfusion in contemporary revision total hip arthroplasty (THA) remains high despite recent advances in blood management, including the use of tranexamic acid. The purpose of this prospective investigation was to determine independent risk factors for transfusion in revision THA. METHODS:Six centers prospectively collected data on 175 revision THAs. A multivariable logistic analysis was performed to determine independent risk factors for transfusion. Revisions were categorized into subgroups for analysis, including femur-only, acetabulum-only, both-component, explantation with spacer, and second-stage reimplantation. Patients undergoing an isolated modular exchange were excluded. RESULTS:Twenty-nine patients required at least one unit of blood (16.6%). In the logistic model, significant risk factors for transfusion were lower preoperative hemoglobin, higher preoperative international normalized ratio (INR), and longer operative time (P < .01, P = .04, P = .05, respectively). For each preoperative 1g/dL decrease in hemoglobin, the chance of transfusion increased by 79%. For each 0.1-unit increase in the preoperative INR, transfusion chance increased by 158%. For each additional operative hour, the chance of transfusion increased by 74%. There were no differences in transfusion rates among categories of revision hip surgery (P = .23). No differences in demographic or surgical variables were found between revision types. CONCLUSION:Despite the use of tranexamic acid, transfusions are commonly required in revision THA. Preoperative hemoglobin and INR optimization are recommended when medically feasible. Efforts should also be made to decrease operative time when technically possible.

BACKGROUND:The use of technology such as navigation and robotic systems may improve the accuracy of component positioning in total hip arthroplasty (THA), but its impact on patient-reported outcome measures (PROMs) remains unclear. This study aims to elucidate the association between the use of intraoperative technology and PROMs in patients who underwent primary THA. METHODS:We retrospectively reviewed a consecutive series of patients who underwent primary THA between 2016 and 2020 and answered PROM questionnaires. Patients were separated into 3 groups depending on intraoperative technology utilization: computer-assisted navigation, robotic-assisted, or no technology (conventional) THA. Forgotten Joint Score-12 and Hip disability and Osteoarthritis Outcome Score, Joint Replacemen scores were collected at various time points. Demographic differences were assessed with chi-square and analysis of variance. Mean scores between groups were compared using univariate analysis of covariance, controlling for all significant demographic differences. RESULTS:Of the 1960 cases identified, 896 used navigation, 135 used robotics, and 929 used no technology. There were significant statistical differences in one-year Hip disability and Osteoarthritis Outcome Score, Joint Replacement scores (85.23 vs 85.95 vs 86.76, respectively; P = .014) and two-year Forgotten Joint Score-12 scores (64.72 vs 73.35 vs 74.63, respectively; P = .004) between the 3 groups. However, these differences did not exceed the mean clinically important differences. Length of stay was statistically longest for patients who underwent conventionally performed THA versus navigation and robotics (2.22 vs 1.46 vs 1.91, respectively; P < .001). Surgical time was significantly longer for cases performed using robotics versus navigation and conventionally (119.61 vs 90.35 vs 95.35, respectively; P < .001). CONCLUSION/CONCLUSIONS:Statistical differences observed between all modalities are not likely to be clinically meaningful with regard to early patient-reported outcomes. Although intraoperative use of technology may improve the accuracy of implant placement, these modalities have not yet translated into improved early reported functional outcomes. LEVEL III EVIDENCE/UNASSIGNED:Retrospective cohort.

BACKGROUND:Vancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections. METHODS:We reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups. RESULTS:We reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012). CONCLUSION/CONCLUSIONS:Late infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.

BACKGROUND:Dual mobility (DM) total hip arthroplasty (THA) implants have been advocated for patients at risk for impingement due to abnormal spinopelvic mobility. Impingement against cobalt-chromium acetabular bearings, however, can result in notching of titanium femoral stems. This study investigated the incidence of femoral stem notching associated with DM implants and sought to identify risk factors. METHODS:A multicenter retrospective study reviewed 256 modular and 32 monoblock DM components with minimum 1-year clinical and radiographic follow-up, including 112 revisions, 4 conversion THAs, and 172 primary THAs. Radiographs were inspected for evidence of femoral notching and to calculate acetabular inclination and anteversion. Revisions and dislocations were recorded. RESULTS:Ten cases of femoral notching were discovered (3.5%), all associated with modular cylindrospheric cobalt-chromium DM implants (P = .049). Notches were first observed radiographically at mean 1.3 years after surgery (range 0.5-2.7 years). Notch location was anterior (20%), superior (60%), or posterior (20%) on the prosthetic femoral neck. Notch depth ranged from 1.7% to 20% of the prosthetic neck diameter. Eight cases with notching had lumbar pathology that can affect spinopelvic mobility. None of these notches resulted in stem fracture, at mean 2.7-year follow-up (range 1-7.6 years). There were no dislocations or revisions in patients with notching. CONCLUSION/CONCLUSIONS:Femoral notching was identified in 3.5% of DM cases, slightly surpassing the dislocation rate in a cohort selected for risk of impingement and instability. Although these cases of notching have not resulted in catastrophic failures thus far, further study of clinical sequelae is warranted. Component position, spinopelvic mobility, and implant design may influence risk.

Background/UNASSIGNED:The purpose of this study is to assess whether racial differences influence patient-reported outcome measures (PROMs) following primary total hip (THA) and knee (TKA) arthroplasty. Methods/UNASSIGNED:We retrospectively reviewed patients who underwent primary THA or TKA from 2016 to 2020 with available PROMs. Both THA and TKA patients were separated into three groups based on their ethnicity: Caucasian, African-American, and other races. Patient demographics, clinical data, and PROMs at various time-periods were collected and compared. Demographic differences were assessed using chi-square and ANOVA. Univariate ANCOVA was utilized to compare outcomes and PROMs while accounting for demographic differences. Results/UNASSIGNED:This study included 1999 THA patients and 1375 TKA patients. In the THA cohort, 1636 (82%) were Caucasian, 177 (9%) were African-American, and 186 (9%) were of other races. In the TKA cohort, 864 (63%) were Caucasian, 236 (17%) were African-American, and 275 (20%) were of other races. Surgical-time significantly differed between the groups that underwent THA (88.4vs.100.5vs.96.1; p < 0.001) with African-Americans requiring the longest operative time. Length-of-stay significantly differed in both THA (1.5vs.1.9vs.1.8; p < 0.001) and TKA (2.1vs.2.5vs.2.3; p < 0.001) cohorts, with African-Americans having the longest stay. Caucasians reported significantly higher PROM scores compared to non-Caucasians in both cohorts. All-cause emergency-department (ED) visits, 90-day postoperative events (readmissions&revisions), and discharge-disposition did not statistically differ in both cohorts. Conclusion/UNASSIGNED:Non-Caucasian patients demonstrated lower PROM scores when compared to Caucasian patients following TJA although the differences may not be clinically relevant. LOS was significantly longer for African-Americans in both THA and TKA cohorts. Further investigation identifying racial disparity interventions is warranted. Level of evidence/UNASSIGNED:Prognostic Level III.

BACKGROUND:Investigations into reimbursement trends for primary and revision arthroplasty procedures have demonstrated a steady decline over the past several years. Revision total hip arthroplasty (rTHA) due to infection (rTHA-I) has been associated with higher resource utilization and complexity, but long-term inflation-adjusted data have yet to be compared between rTHA-I and rTHA due to aseptic complications (rTHA-A). The present study was performed to analyze temporal reimbursement trends regarding rTHA-I procedures compared with those for rTHA-A procedures. METHODS:The Centers for Medicare & Medicaid Services (CMS) Physician Fee Schedule Look-Up Tool was used to extract Medicare reimbursements associated with 1-stage and 2-stage rTHA-I as well as 1-stage rTHA-A procedures from 2002 to 2019. Current Procedural Terminology (CPT) codes for rTHA were grouped according to the American Academy of Orthopaedic Surgeons coding reference guide. Monetary values were adjusted for inflation using the consumer price index (U.S. Bureau of Labor Statistics; reported as 2019 U.S. dollars) and used to calculate the cumulative and average annual percent changes in reimbursement. RESULTS:Following inflation adjustment, the physician fee reimbursement for rTHA-A decreased by a mean [and standard deviation] of 27.26% ± 3.57% (from $2,209.11 in 2002 to $1,603.20 in 2019) for femoral component revision, 27.41% ± 3.57% (from $2,130.55 to $1,542.91) for acetabular component revision, and 27.50% ± 2.56% (from $2,775.53 to $2,007.61) for both-component revision. Similarly, for a 2-stage rTHA-I, the mean reimbursement declined by 18.74% ± 3.87% (from $2,063.36 in 2002 to $1,673.36 in 2019) and 24.45% ± 3.69% (from $2,328.79 to $1,755.45) for the explantation and reimplantation stages, respectively. The total decline in physician fee reimbursement for rTHA-I ($1,020.64 ± $233.72) was significantly greater than that for rTHA-A ($580.72 ± $107.22; p < 0.00001). CONCLUSIONS:Our study demonstrated a consistent devaluation of both rTHA-I and rTHA-A procedures from 2002 to 2019, with a larger deficit seen for rTHA-I. A continuation of this trend could create substantial disincentives for physicians to perform such procedures and limit access to care at the population level. LEVEL OF EVIDENCE/METHODS:Economic and Decision Analysis Level IV. See Instructions for Authors for a complete description of levels of evidence.

INTRODUCTION/BACKGROUND:There is debate regarding whether the use of computer-assisted technology, such as navigation and robotics, has any benefit on outcomes or patient-reported outcome measures (PROMs) following total knee arthroplasty (TKA). This study aims to report on the association between intraoperative use of technology and outcomes in patients who underwent primary TKA. METHODS:We retrospectively reviewed 7096 patients who underwent primary TKA from 2016-2020. Patients were stratified depending on the technology utilized: navigation, robotics, or no technology. Patient demographics, clinical data, Forgotten Joint Score-12 (FJS), and Knee injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS, JR) were collected at various time points up to 1-year follow-up. Demographic differences were assessed with chi-square and ANOVA. Clinical data and PROMs were compared using univariate ANCOVA, controlling for demographic differences. RESULTS:A total of 287(4%) navigation, 367(5%) robotics, and 6442(91%) manual cases were included. Surgical-time significantly differed between the three groups (113.33 vs 117.44 vs 102.11; P < .001). Discharge disposition significantly differed between the three groups (P < .001), with more manual TKA patients discharged to a skilled nursing facility (12% vs 8% vs 15%; P < .001) than those who had technology utilized. FJS scores did not statistically differ at three-months (P = .067) and one-year (P = .221). We found significant statistical differences in three-month KOOS, JR scores (59.48 vs 60.10 vs 63.64; P = .001); however, one-year scores did not statistically differ between all groups (P = .320). CONCLUSION/CONCLUSIONS:This study demonstrates shorter operative-time in cases with no utilization of technology and clinically similar PROMs associated with TKAs performed between all modalities. While the use of technology may aid surgeons, it has not currently translated to better short-term outcomes. LEVEL III EVIDENCE/UNASSIGNED:Retrospective Cohort.

BACKGROUND:While vancomycin powder and dilute povidone-iodine (VIP) is associated with fewer total joint arthroplasty (TJA) periprosthetic joint infections (PJI), its effect on PJI organism profiles is unclear. This study evaluates primary TJA PJI organism profiles before and after the implementation of a VIP protocol. METHODS:In total, 18,299 primary TJAs performed at a university-affiliated, not-for-profit orthopedic hospital from before (1/2012-12/2013) and after (1/2016-12/2019) a VIP protocol was initiated were reviewed to identify deep PJIs that occurred within 90 days of the index arthroplasty as defined by the Musculoskeletal Infection Society guidelines. Demographics, overall organism incidence (n/TJAs), and relative organism incidence (n/PJIs) from the two cohorts were compared. RESULTS:In total, 103 TJA PJIs were identified (pre-VIP: 32/3982; VIP: 71/14,317). Following the introduction of VIP, the overall and relative incidence of coagulase-negative staphylococcal TJA PJIs significantly decreased (overall: 0.20% to 0.04%, P = .004; relative: 25.00% to 8.45%, P = .031). In response, the relative incidence of MSSA TJA PJIs significantly increased (18.75% to 40.85%, P = .042). Broken down by arthroplasty type, VIP was associated with a significantly lower overall incidence of coagulase-negative staphylococcal total knee arthroplasty (TKA) PJIs (0.27% to 0.06%, P = .015), a significantly lower overall incidence of MRSA TKA PJIs (0.18% to 0.03%, P = .031), and a nonsignificant decrease in the overall incidence of gram-negative TKA PJIs (0.18% to 0.04%, P = .059). No organism profile changes were found in total hip arthroplasty PJIs. CONCLUSION/CONCLUSIONS:VIP is not associated with more difficult to treat primary TJA PJIs. While promising, these findings require a prospective randomized controlled trial for confirmation. LEVEL OF EVIDENCE/METHODS:Level III, Retrospective cohort study.

BACKGROUND:Opioids have played an important part in post-operative analgesia, but concerns with associated morbidity and the fate of leftover pills have prompted the creation of opioid-sparing protocols. The purpose of this study is to investigate the impact of the implementation of an opioid-sparing protocol on survey-based patient satisfaction scores following total hip arthroplasty (THA). METHODS:This study is a retrospective review of prospectively collected data on patients who underwent primary THA between November 2014 and July 2019. Inclusion criteria consisted of primary elective THA with complete Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey information. Cohorts were separated based on their date of surgery relative to the start of an institutional opioid-sparing-protocol in October 2018. Discharge prescriptions and refills were recorded on chart review and converted to milligram morphine equivalents (MME) for comparison between different opioids. HCAHPS results were analyzed for percentage of "top box" ratings for comparison between the 2 groups. RESULTS:In total, 1003 patients met inclusion criteria: 804 pre-protocol and 199 post-protocol. Mean length of stay decreased from 1.74 ± 1.03 to 1.50 ± 1.11 days (P < .001). Pre-operative Visual Analog Scale pain decreased from 7.00 ± 2.30 to 6.41 ± 2.66 (P = .011) as did the rate of opioid refills (15.6%-9.1%; P = .019). Quantity of opioid medication prescribed upon discharge also decreased from 432 ± 298 to 114 ± 156 MME (P < .001). There was no change in "top box percentages" for satisfaction with pain control (79.7% pre-protocol, 82.1% post-protocol; P = .767). There was a significant increase in proportion of patients reporting top box satisfaction with their overall surgical experience after protocol implementation (88.2%-94.0%; P = .018). CONCLUSION/CONCLUSIONS:A reduction in opioids prescribed after THA is not associated with a decrease in patient satisfaction with regard to pain control, as measured by the HCAHPS survey, nor is it associated with an increase in post-operative opioid refills. LOE: III. CLINICAL RELEVANCE/CONCLUSIONS:This study suggests that HCAHP scores are not negatively impacted by a reduction in post-operative opioid analgesics.

BACKGROUND:To create a safe zone, an understanding of the combined femoral and acetabular mating during hip motion is required. We investigated the position of the femoral head inside the acetabular liner during simulated hip motion. We hypothesized that cup and stem anteversions do not equally affect hip motion and combined hip anteversion. METHODS:Hip implant motion was simulated in standing, sitting, sit-to-stand, bending forward, squatting, and pivoting positions using the MATLAB software. A line passing through the center of the stem neck and the center of the prosthetic head exits at the polar axis (PA) of the prosthetic head. When the prosthetic head and liner are parallel, the PA faces the center of the liner (PA position = 0, 0). By simulating hip motion in 1-degree increments, the maximum distance of the PA from the liner center and the direction of its movement were measured (polar coordination system). RESULTS:The effect of modifying cup and stem anteversion on the direction and distance of the PA's change inside the acetabular liner was different. Stem anteversion influenced the PA position inside the liner more than cup anteversion during sitting, sit-to-stand, squatting, and bending forward (P = .0001). This effect was evident even when comparing stems with different neck angles (P = .0001). CONCLUSION:Cup anteversion, stem anteversion, and stem neck-shaft angle affected the PA position inside the liner and combined anteversion in different ways. Thus, focusing on cup orientation alone when assessing hip motion during different daily activities is inadequate.