Faculty Bibliography

INTRODUCTION/BACKGROUND:The purpose of this multicenter, double-blinded, prospective, randomized controlled trial was to determine the safest and most effective dose of intravenous (IV) dexamethasone administered during primary total knee arthroplasty (TKA). METHODS:There were 404 patients undergoing inpatient primary TKA randomized across 11 centers to receive four mg (n = 138), eight mg (n = 137), or 16 mg (n = 129) of IV dexamethasone intraoperatively. All sites utilized the same perioperative multimodal protocol. Opioid consumption measured in morphine milligram equivalents (MME), pain scores, nausea scores, vomiting episodes, and sleep duration was collected for seven days postoperatively. Glucose levels were measured on postoperative day (POD) one. The mean age was 68 years, the mean body mass index was 33, and 62% were women. Independent sample t-tests were used for continuous data, and Chi-square and Fisher's exact tests were used for discrete data. Demographic characteristics were comparable between groups, suggesting successful randomization. RESULTS:Patients who received 16 mg IV dexamethasone consumed less MME on POD one (38 versus 37 versus 27 MME; P = 0.047) and had fewer vomiting episodes (P = 0.02). Patients who received 16 mg also had lower pain scores at rest at 24 hours, 48 hours, and one week. There were no differences in cumulative opioid consumption within the first 48 hours (P = 0.24), one week (P = 0.43), or pain with activity at any time point. The POD one glucose was highest in patients who received 16 mg (P < 0.001). There were no differences in length of stay, hours slept, or 90-day complication rates between groups. CONCLUSION/CONCLUSIONS:High-dose (16 mg) IV dexamethasone in TKA reduces opioid consumption, pain, and vomiting on the first day after surgery. Outcomes, including opioid consumption, sleep, and nausea, are comparable beyond 24 hours for all doses.

INTRODUCTION/BACKGROUND:Maintaining follow-up after total joint arthroplasty (TJA) is critical to monitor patient outcomes and complications. However, patient factors associated with follow-up compliance have not been described previously. This study aimed to characterize demographic and perioperative characteristics associated with TJA follow-up compliance. METHODS:This was a retrospective review of all primary, elective total hip and knee arthroplasty (THA and TKA) procedures at an urban, tertiary care center from 2011 to 2022. Patient follow-ups were categorized as early (0 to 90 days), mid-term (91 days to two years), and late-term (greater than two years). Patient characteristics, including age, sex, race, smoking status, spoken language, body mass index, income class, insurance type, distance from hospital, 90-day readmission, American Society of Anesthesia Status, and Charlson Comorbidity Index (CCI), were compared at each period, and logistic regression identified predictors of follow-up. RESULTS:In total, 2,836 TKA and 3,056 THA procedures were analyzed, with overall follow-up rates of 78.9 and 76.8%, respectively. Among all TJA patients, those who did not have follow-up were more likely to be younger, men, White, active smokers, live further from the hospital, and have lower CCIs. Uniquely, for TKA patients, higher income status predicted lower overall and early follow-up rates, while English-speaking predicted lower early and higher late follow-up rates in this subgroup. Differences between groups based on follow-up status decreased as follow-up time increased. Regression analyses showed loss to follow-up increased with increased distance from the hospital and current smoking. Uniquely, for THA, men predicted loss-to-follow-up. CONCLUSION/CONCLUSIONS:Younger age, men, White race, higher income, current smoking, and increased distance from the hospital are associated with increased early, but not late, loss to follow-up after TJA. Future studies should assess the influence of other factors, including home support and telemedicine use, on follow-up rates.

AIMS/UNASSIGNED:The aim of this study was to assess the variations in the positioning of components between sides in patients who underwent staged bilateral total hip arthroplasty (THA), and whether these variations affected patient-reported outcome measures (PROMs). METHODS/UNASSIGNED:A retrospective review included 207 patients who underwent staged bilateral THA between June 2017 and November 2022. Leg length, the height and anteversion of the acetabular component, and the coronal and sagittal angles of the femoral component were assessed radiologically and compared with the contralateral THA. The effect of the surgical approach and the technology used on this variation was also assessed. Linear regression was used to investigate the variations between the two THAs and the PROMs. RESULTS/UNASSIGNED:Between the two sides, the mean leg length varied by 4.6 mm (0.0 to 21.2), the mean height of the acetabular component varied by 3.3 mm (0.0 to 13.7), the mean anteversion varied by 8.2° (0.0° to 28.7°), the mean coronal alignment of the femoral component varied by 1.1° (0.0° to 6.9°), and the mean sagittal alignment varied by 2.3° (0.0° to 10.5°). The use of the direct anterior approach resulted in significantly more variation in the alignment of the femoral component in both the coronal (1.3° vs 1.0°; p = 0.036) and sagittal planes (2.8° vs 2.0°; p = 0.012) compared with the use of the posterior approach. The posterior approach generally led to more anteversion of the acetabular component than the anterior approach. The use of robotics or navigation for positioning the acetabular compoment did not increase side-to-side variations in acetabular component-related positioning or leg length. Despite considerable side-to-side variations, the mean Hip disability and Osteoarthritis Outcome, Joint Replacement (HOOS JR) score was not affected by variations in the postioning of the components. CONCLUSION/UNASSIGNED:Staged bilateral THA resulted in considerable variation in the positioning of the components between the two sides. The direct anterior approach led to more variations in anteversion of the acetabular component and sagittal alignment of the femoral component than the posterior approach. The use of computer navigation and robotics did not improve the consistency of the positioning of the components in bilateral THA. Variations in the positioning of the components was not associated with differences in PROMs, indicating that patients can tolerate these differences.

The efficacy of "Expanded Gram-Negative Antimicrobial Prophylaxis" (EGNAP) in preventing postoperative infections has been previously reported in total hip arthroplasty (THA). However, it remains unclear as to whether these benefits extend to total knee arthroplasty (TKA). This study investigated whether adding EGNAP to our institution's preoperative antibiotic prophylaxis protocol would affect periprosthetic joint infection (PJI) risk in TKA patients. We retrospectively reviewed 10,666 elective, unilateral, primary TKA cases performed at a single-specialty tertiary academic hospital from 2018 to 2022. Before June 2021, all patients received 2 g of cefazolin for 24 h as part of the prophylactic antibiotic protocol. After June 2021, gentamicin or aztreonam (EGNAP) was added to the protocol for all TKA patients. Patients were grouped based on whether they received EGNAP or not (control group) before surgery. The groups were propensity score-matched in a 2:1 ratio. PJI and nephrotoxicity (using RIFLE criteria) risk was compared. After matching, the final study population consisted of 3007 patients in the non-EGNAP group and 1503 patients in the EGNAP group. There was no significant difference between the EGNAP and no EGNAP groups in the overall incidence of PJI (1.9% vs. 2.0%; p = 0.111) or the incidence of Gram-positive PJIs (0.3% vs. 0.8%; p = 0.103). The incidence of Gram-negative PJIs was 0.5% in the EGNAP group and 0.4% in the no EGNAP group, which was also not different between the groups (p = 0.692). There were no differences in nephrotoxicity between groups (p = 0.521). The addition of EGNAP to the antibiotic prophylactic protocol prior to TKA had no effect on overall or Gram-negative PJI risk in TKA patients. The findings of this study suggest that while EGNAP is safe to use and has minimal nephrotoxic effects, its prophylactic benefits do not extend to the primary TKA population. This may be attributed to the generally low rate of Gram-negative infections in TKA patients, where adding EGNAP does not provide a clear advantage in reducing the risk of such infections, unlike its potential benefits in primary THA population. This study investigates the effects of using prophylactic Gram-negative antibiotics prior to TKA and shows that though it is safe to use, Gram-negative bacterial coverage may have no impact on postoperative infection incidence.

INTRODUCTION/BACKGROUND:Previous studies have identified perioperative gastric aspiration events as a contributor to varying outcomes following orthopedic trauma patients. However, current literature does not report on the effect an aspiration event has on outcomes for patients undergoing total hip arthroplasty (THA) or total knee arthroplasty (TKA), nor do current studies identify risk factors for perioperative aspiration events. MATERIALS AND METHODS/METHODS:We retrospectively reviewed patients who underwent primary, unilateral total joint arthroplasty (TJA) from May 2011 to December 2021. Patients undergoing primary THA/TKA for fracture and oncological indications were excluded. A total of 35,108 patients were stratified according to no aspiration event (35,077 patients) or perioperative aspiration event (intraoperative, day zero, to day seven, 31 patients). Patient demographics and clinical outcomes data were collected and compared. RESULTS:The perioperative aspiration group had a higher average Charlson Comorbidity Index (CCI) (4.03 vs. 2.96, p = 0.008). The aspiration group was more likely to be placed in a lateral decubitus position (54.8% vs. 30.5%, p = 0.003). Patients experiencing an aspiration event had a longer length of stay (LOS) (5.74 vs. 2.66, p < 0.001) and lower rates of home discharge (58.1% vs. 82.5%; p < 0.001). No difference in adverse outcomes such as rate of readmission, revision, and mortality were observed between groups. Multivariable regressions did not show significantly higher odds of aspiration based on surgery type, positioning, or any other demographic factors. CONCLUSION/CONCLUSIONS:This study demonstrates that patients experiencing a perioperative aspiration event during or immediately following TJA do not incur higher rates of readmission, revision, or mortality if treated in a timely manner. However, they do incur longer LOS and higher non-home discharge rates. Further research can explore non-demographic risk factors for perioperative aspiration.

BACKGROUND:Two-stage revisions for chronic periprosthetic joint infections (PJIs) often include antibiotic-loaded cement spacers to control for infection and preserve function. While studies have reported on complications (dislocations, readmissions, and reoperations) after static versus articulating spacer types, there is a paucity of evidence about whether the degree of spacer constraint in articulating spacers affects these complications. This study aims to address a key gap in understanding as to whether the level of spacer constraint affects complications in two-stage revision THA utilizing articulating spacers. QUESTIONS/PURPOSES/OBJECTIVE:(1) Among patients receiving nonconstrained versus constrained articulating antibiotic spacers during first-stage revision THA for PJI, are there differences in major complications, such as dislocation, loosening, periprosthetic fracture, reinfection, and unplanned revisions? (2) After second-stage reimplantation, do patients who received a nonconstrained versus constrained liner during the first stage show differences in the risk of complications, reoperations, and readmissions? METHODS:This is a retrospective review of 539 patients who underwent two-stage revision THA for PJI at a single-specialty, urban academic referral center between July 2011 and March 2023. Of these 539 patients, 72% (388) were excluded for undergoing a full component revision (femoral or acetabular) for any reason before their first stage, 3% (15) for receiving static spacers, and 6% (35) for receiving prefabricated femoral mono-block stems as part of their first stage. Those who underwent only liner exchange were not excluded. The remaining 19% (101 of 539) of patients were included in the final analysis and categorized by degree of liner constraint: 32 were in the nonconstrained group and 69 were in the constrained group. All surgeons included in this study specialize in adult reconstruction and are fellowship trained, and the selected level of constraint was solely based on their routine practice for articulating spacer construct. Baseline characteristics and clinical data, including age, self-reported gender, race, BMI, American Society of Anesthesiologists score, smoking status, surgical history, and perioperative details, were collected. There were no differences in baseline characteristics between the groups except for smoking status. A priori power analysis determined that 150 patients (75 per group) would be needed to detect a statistical difference in the risk of dislocation between groups, assuming a 20% dislocation risk for the constrained group, at a 0.05 alpha level, and 80% power. RESULTS:Between patients receiving nonconstrained versus constrained liners, there were no differences in complications after the first stage of revision. Three percent (1 of 32) of the nonconstrained liners developed dislocations compared with 3% (2 of 69) in the constrained group (relative risk [RR] 1.1 [95% confidence interval (CI) 0.09 to 12.3]; p > 0.99). Three percent (1 of 32) of the nonconstrained group developed periprosthetic fractures compared with 7% (5 of 69) in the constrained group (RR 0.4 [95% CI 0.05 to 3.69]; p = 0.72). Similarly, 3% (1 of 32) versus 7% (5 of 69) had persistent infection (RR 0.4 [95% CI 0.05 to 3.69]; p = 0.72). One incident of loosening occurred in the constrained group. There were also no differences in spacer revision incidence: 10% (3 of 32) of the nonconstrained group and 10% (7 of 69) of the constrained group underwent an unplanned revision after the first stage (RR 1.0 [95% CI 0.29 to 3.91]; p = 0.91). For the second stage, dislocation was 14% (3 of 21) in the nonconstrained group and 10% (5 of 52) in the constrained group (RR 1.1 [95% CI 0.2 to 5.9]; p > 0.99). When comparing periprosthetic fractures, 10% (2 of 21) of the nonconstrained group developed periprosthetic fractures compared with 4% (2 of 52) in the constrained group (RR 2.2 [95% CI 0.3 to 16.6]; p = 0.78). Nineteen percent (4 of 21) in the nonconstrained group had persistent infection compared with 12% (6 of 52) in the constrained group (RR 1.5 [95% CI 0.39 to 5.74]; p = 0.81). The occurrence of readmission after the second stage was 19% (4 of 21) in the nonconstrained group compared with 15% (8 of 52) in the constrained group (RR 1.1 [95% CI 0.3 to 3.9]; p > 0.99). Twenty-four percent (5 of 21) of patients in the nonconstrained group required a surgery-related emergency department visit compared with 13% (7 of 52) in the constrained group (RR 1.6 [95% CI 0.4 to 5.6]; p = 0.64). The incidence of reoperation was 14% (3 of 21) in the nonconstrained group and 13% (7 of 52) in the constrained group (RR 0.9 [95% CI 0.2 to 3.8]; p > 0.99). CONCLUSION/CONCLUSIONS:Our results indicated no differences in the risk of dislocations, reinfections, reoperations, and readmissions between patients undergoing constrained versus nonconstrained articulating spacers for two-stage revision THA. Because constrained liners are typically preferred in patients at higher risk of instability, our findings suggest that their use does not necessarily increase the risk of complications. However, because of the small sample size, larger studies are needed to demonstrate whether there is superiority of liner constraint in this patient population. LEVEL OF EVIDENCE/METHODS:Level III, therapeutic study.

BACKGROUND:Optimal femoral stem alignment and femoral canal fill have been associated with improved osteointegration in patients undergoing cementless total hip arthroplasty (THA). Direct anterior approach (DAA) has become more popular among new surgeons, and the ability to achieve appropriate stem alignment and canal fill due to limited surgical exposure may pose added risks. To mitigate these concerns, several modern tissue sparing stem designs have been designed. This study aimed to compare implant canal fill and alignment between two of the leading DAA-friendly femoral stems available. METHODS:This was a multi-center, retrospective study of patients who underwent DAA THA with either A (n = 149) or B stem (n = 85) between 2021 and 2023 and had a minimum one-year follow-up. Radiographic measures of proximal femoral morphology, including canal calcar ratio (CCR), Morphological Cortical Index (MCI), and Dorr Class (based on the CCR), as well as postoperative measures including femoral canal fill ratio (CFR), signs of osteointegration and stem alignment were analyzed and compared between stem types. RESULTS:, p = 0.082). Spot weld formation was significantly higher in stem A group (59.7% vs. 37.6%, P = 0.001). CONCLUSION/CONCLUSIONS:For patients with similar femoral morphology undergoing DAA THA, the stem A group demonstrated superior anatomical fit in the metaphyseal region, as evidenced by CFR, spot weld formation and implant positioning. Further longer follow up research is needed to elucidate these findings and their correlation to clinical outcomes.

BACKGROUND:Methylene blue (MB), a phenothiazine dye with antimicrobial activity, is used to stain soft tissues and guide thoroughness of debridement during revision total knee arthroplasty (rTKA) for periprosthetic joint infection (PJI). The purpose of this study was to determine if instillation of MB prior to arthrotomy impacts culture yield in TKA PJI. METHODS:We retrospectively reviewed 266 patients diagnosed with TKA PJIs according to the 2018 International Consensus Meeting (ICM) criteria from January 2018 - March 2023 at a single academic hospital. Demographics, perioperative outcomes, and preoperative and intraoperative culture positivity were compared between patients who received intraoperative MB (MB group; n = 26) and those who did not (nMB group; n = 241). A record of detected organisms was included in the analysis. RESULTS:There was no difference in preoperative aspiration culture positivity between groups. However, the MB group had a higher percentage of preoperative to intraoperative culture concordance (89.5 vs. 69.9%; P = 0.04). Although the overall rate of intraoperative culture positivity did not differ significantly between groups, the MB group had more intraoperative cultures obtained per patient (4.9 vs. 4.5; P = 0.02) and higher numbers of positive intraoperative cultures per patient. Concordance rates for patients in both groups with positive preoperative and negative intraoperative cultures were similar (10.5 vs. 16.5%, P = 0.50). Among patients with negative preoperative cultures, intraoperative culture positivity was more discordant in the MB group (0 vs. 18.8%; P = 0.03). There was no difference in the number of patients that received antibiotics following aspiration (68.4 vs. 49.6%; P = 0.12). CONCLUSION/CONCLUSIONS:While MB use did not affect overall culture positivity, it could interfere with intraoperative pathogen detection in patients with negative preoperative cultures. In these cases, MB should be avoided to decrease inaccuracies in intraoperative culture yield. If preoperative cultures are positive, MB may improve surgical debridement and likelihood of infection eradication.

BACKGROUND:Cementless total knee arthroplasty (TKA) has recently regained popularity, yet data has raised concerns about rates of arthrofibrosis following these procedures. The purpose of this study was to utilize the American Joint Replacement Registry to compare rates of early manipulation under anesthesia (MUA) in cementless and cemented primary TKAs that use technology or manual instrumentation. METHODS:We queried the American Joint Replacement Registry for all patients ages 18 to 95 years who underwent cemented or cementless primary TKA over a 7-year period. Patients were stratified based on whether technology (robotics or computer-assisted navigation) was used during the primary surgery. Groups were then compared for rates of MUA within 90-day of the index surgery using multivariable logistic regression models. A total of 340,841 cases were included in the study, 78,397 (23%) of which used technology and 262,444 (77%) which did not. Within the technology cohort, there were 51,500 (65%) robotic and 26,897 (35%) navigated cases. There were 65% of technology-assisted TKAs and 92% of manual TKAs cemented. RESULTS:In the technology group, multivariable analysis demonstrated significantly higher odds of MUA in cemented TKAs compared to cementless (odds ratio [OR] 1.95, 95% confidence interval [CI] [1.06 to 3.59]; P = 0.031). Robotic cases had significantly higher odds of MUA with cemented compared to cementless implants (OR 2.38, 95% CI [1.27 to 4.46]; P = 0.007), while there was no difference in MUA related to cementation in the navigated cases (OR 3.53, 95% CI [0.48 to 25.95]; P = 0.22). In the manual group, there were no significant differences in MUA rates related to cementation use (OR 1.14, 95% CI [0.8 to 1.64]; P = 0.46). CONCLUSIONS:Cementless TKA did not increase odds of MUA. In further analyzing cement use into technology and manual cohorts, robotic-assisted cemented TKAs had higher rates of early MUA than cementless. Identification of risk factors leading to early arthrofibrosis may be patient dependent and further study is required to elucidate any surgical considerations.

BACKGROUND:High body mass index (BMI) is a risk factor for tibial baseplate loosening following total knee arthroplasty (TKA) but may not adequately correlate with stresses at the tibial baseplate. In this study, we aimed to determine an optimal cutoff of a weight-to-tibial baseplate surface-area ratio (weight/SA) for predicting aseptic tibial baseplate loosening. We further examined whether tibial stem extensions have a protective effect. METHODS:We identified 16,368 patients who underwent primary, elective TKA from June 2011 to March 2023. Patient demographics, including age, sex, and race, implants used, and revision surgeries were extracted. Revisions were manually reviewed to confirm revision indications. The exact surface areas of tibial baseplates were obtained from manufacturers. Receiver operating characteristic (ROC) analysis of patients without tibial stem extensions was utilized to examine the utility of BMI and weight/SA for predicting aseptic tibial baseplate loosening. Optimal weight/SA and BMI cutoffs for predicting loosening were determined. The effect of tibial stem extensions on loosening was then examined in patients at or above (n = 7,698; 3.7% with stem extension) and below (n = 8,670; 1.3% with stem extension) the determined weight/SA cutoff. RESULTS:There were 16,368 patients in the final sample (median age, 67 years; 68.9% female; 54.1% White). Weight/SA (area under the curve [AUC] = 0.653; p < 0.001) was a better predictor of aseptic tibial baseplate loosening requiring revision compared with patient BMI (AUC = 0.624; p < 0.001). The optimal weight/SA cutoff for predicting loosening was 0.0162 kg/mm2 (sensitivity = 0.747, specificity = 0.537). Multivariable logistic regression demonstrated that being at or above the weight/SA cutoff (odds ratio [OR] = 3.17; p < 0.001) but not the BMI cutoff (p = 0.911) was a significant predictor of revision for tibial baseplate loosening in patients without stem extensions. No cases of revision for aseptic tibial baseplate loosening in patients with stem extensions occurred either at or above or below the cutoff. The rate of revision for aseptic tibial baseplate loosening in patients without stem extensions was 0.3% for patients below and 1.0% for patients at or above the weight/SA cutoff. CONCLUSIONS:The ratio of weight-to-tibial baseplate surface area was more predictive of revision for aseptic tibial baseplate loosening following TKA compared with BMI alone. For patients with obesity with small tibial baseplate sizes, utilization of a tibial stem extension may protect against tibial loosening. LEVEL OF EVIDENCE/METHODS:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.