Faculty Bibliography

Culture-positive (CP) and culture-negative (CN) periprosthetic joint infections (PJI) remain a crucial area of research; however, current studies comparing these infections rely on unstandardized outcome reporting tools. Our study aimed to compare the outcomes of two-stage revision of CP and CN PJI using the standardized Musculoskeletal Infection Society (MSIS) outcome reporting tool. We retrospectively reviewed 138 patients who were diagnosed with PJI and indicated for two-stage revision total knee arthroplasty (rTKA). The majority of patients in both CP and CN cohorts achieved infection control without the need for reoperation (54.1% and 62.5%, respectively). There was a significant difference in the overall distribution of MSIS outcomes (p = 0.043), with a significantly greater rate of CN patients falling into Tier 1 (infection control without the use of suppressive antibiotics) (52.5% versus 29.6%, p = 0.011). There was also a significant difference in the distribution of septic versus aseptic reoperations after 2nd stage (p = 0.013), with more CP reoperations being septic and more CN reoperations being aseptic. The duration from first to second stage was significantly shorter in the CN cohort (p = 0.002). While overall infection control was similar between cohorts, these data suggest that the outcomes of two-stage rTKA are favorable in cases of CN PJI.

Periprosthetic joint infections (PJIs) are a devastating complication of joint arthroplasty surgeries that are often complicated by biofilm formation. The development of biofilms makes PJI treatment challenging as they create a barrier against antibiotics and host immune responses. This review article provides an overview of the current understanding of biofilm formation, factors that contribute to their production, and the most common organisms involved in this process. This article focuses on the identification of biofilms, as well as current methodologies and emerging therapies in the management of biofilms in PJI.

INTRODUCTION/BACKGROUND:Understanding the trends among patients undergoing same-day discharge (SDD) total hip arthroplasty (THA) is imperative to highlight the progression of outpatient surgery and the criteria used for enrollment. The purpose of this study was to identify trends in demographic characteristics and outcomes among patients who participated in an academic hospital SDD THA program over 6 years. METHODS:We retrospectively reviewed all patients who enrolled in our institution's SDD THA program from January 2015 to October 2020. Patient demographics, failure-to-launch rate, as well as readmission and revision rates were evaluated. Trends for continuous variables were analyzed using analysis of variance, and categorical variables were analyzed using chi-square tests. RESULTS:In total, 1,334 patients participated in our SDD THA program between 2015 and 2020. Age (54.82 to 57.94 years; P < 0.001) and mean Charlson Comorbidity Index (2.15 to 2.90; P < 0.001) significantly differed over the 6-year period. More African Americans (4.3 to 12.3%; P = 0.003) and American Society of Anesthesiology class III (3.2% to 5.8%; P < 0.001) patients enrolled in the program over time. Sex ( P = 0.069), BMI ( P = 0.081), marital status ( P = 0.069), and smoking status ( P = 0.186) did not statistically differ. Although the failure-to-launch rate (0.0% to 12.0%; P < 0.001) increased over time, the 90-day readmissions ( P = 0.204) and 90-day revisions ( P = 0.110) did not statistically differ. CONCLUSION/CONCLUSIONS:More African Americans, older aged individuals, and patients with higher preexisting comorbidity burden enrolled in the program over this period. Our findings are a reflection of a more inclusive selection criterion for participation in the SDD THA program. These results highlight the potential increase in the number of patients and surgeons interested in SDD THA, which is paramount in the current incentivized and value-based healthcare environment. LEVEL EVIDENCE/METHODS:III, Retrospective Review.

Postoperative stiffness is a challenging problem in the setting of primary total knee arthroplasty. There remains a relatively high prevalence of patients suffering from this condition, and it can lead to unsatisfactory outcomes and need for revision surgery as well as a large financial burden on the health care system. There are a number of factors that predispose patients to developing arthrofibrosis, including patient-specific factors and intraoperative and postoperative considerations. Arthrofibrosis can be treated effectively in the early stages with manipulation under anesthesia with or without lysis of adhesions, however, those who fail to respond to these interventions may require revision surgery, which generally has poorer outcomes when performed for this indication. Current research is focused on understanding the pathologic cascade of arthrofibrosis and novel targeted therapeutics that may decrease stiffness in these patients and improve outcomes.

Prosthetic joint infection (PJI) remains a major cause of failure in total joint arthroplasty. This complication begets an increase in morbidity and mortality along with significant costs to the healthcare system. The use of prophylactic antibiotics has significant decreased the incidence of this complication. However, the incidence of PJI has not drastically decreased over the last 50 years. This review explores the history, current concepts, and future developments for prevention of PJI prior to incision in total joint arthroplasty.

INTRODUCTION/UNASSIGNED:There has been much debate on use of bipolar or unipolar femoral heads in hemiarthroplasty for the treatment of femoral neck fractures. The outcome of these implants should be studied in the America Joint Replacement Registry (AJRR). METHODS/UNASSIGNED:All primary femoral neck fractures treated with hemiarthroplasty between January 2012 and June 2020 were searched in the AJRR. All cause-revision of unipolar and bipolar hemiarthroplasty and reasons for revision were assessed for these patients until June of 2023. RESULTS/UNASSIGNED: 0.0192) had a significant increase in revision risk. CONCLUSIONS/UNASSIGNED:We suggest that surgeons should consider using bipolar prosthesis when performing hemiarthroplasty for femoral neck fracture in patients expected to live >2 years post injury.

BACKGROUND:Manipulation under anesthesia (MUA) occurs in 4% of patients after total knee arthroplasty (TKA). Anti-inflammatory medications may target arthrofibrosis pathogenesis, but the data are limited. This multicenter randomized clinical trial investigated the effect of adjuvant anti-inflammatory medications with MUA and physical therapy on range of motion (ROM) and outcomes. METHODS:There were 124 patients (124 TKAs) who developed stiffness after primary TKA for osteoarthritis enrolled across 15 institutions. All received MUA when ROM was < 90° at 4 to 12 weeks postoperatively. Randomization proceeded via a permuted block design. Controls received MUA and physical therapy, while the treatment group also received one dose of pre-MUA intravenous dexamethasone (8 mg) and 14 days of oral celecoxib (200 mg). The ROM and clinical outcomes were assessed at 6 weeks and 1 year. This trial was registered with ClinicalTrials.gov. RESULTS:The ROM significantly improved a mean of 46° from a pre-MUA ROM of 72 to 118° immediately after MUA (P < .001). The ROM was similar between the treatment and control groups at 6 weeks following MUA (101 versus 99°, respectively; P = .35) and at one year following MUA (108 versus 108°, respectively; P = .98). Clinical outcomes were similar at both end points. CONCLUSIONS:In this multicenter randomized clinical trial, the addition of intravenous dexamethasone and a short course of oral celecoxib after MUA did not improve ROM or outcomes. However, MUA provided a mean ROM improvement of 46° immediately, 28° at 6 weeks, and 37° at 1 year. Further investigation in regards to dosing, duration, and route of administration of anti-inflammatory medications remains warranted. LEVEL OF EVIDENCE/METHODS:Level 1, RCT.

BACKGROUND/UNASSIGNED:Increased load bearing across the patellofemoral and tibiofemoral articulations has been associated with total knee arthroplasty (TKA) complications. Therefore, the purpose of this study was to quantify the biomechanical characteristics of the patellofemoral and tibiofemoral joints and simulate varying weight-bearing demands after posterior cruciate ligament-retaining (CR) and posterior-stabilized (PS) TKAs. METHODS/UNASSIGNED:Eight fresh-frozen cadaveric knees (average age, 68.4 years; range, 40-86 years) were tested using a custom knee system with muscle-loading capabilities. The TKA knees were tested with a CR and then a PS TKA implant and were loaded at 6 different flexion angles from 15° to 90° with progressively increasing loads. The independent variables were the implant types (CR and PS TKA), progressively increased loading, and knee flexion angle (KFA). The dependent variables were the patellofemoral and tibiofemoral kinematics and contact characteristics. RESULTS/UNASSIGNED:The results showed that at higher KFAs, the position of the femur translated significantly more posterior in CR implants than in PS implants (36.6 ± 5.2 mm and 32.5 ± 5.7 mm, respectively). The patellofemoral contact force and contact area were significantly greater in PS than in CR implants at higher KFAs and loads (102.4 ± 12.5 N and 88.1 ± 10.9 N, respectively). Lastly, the tibiofemoral contact force was significantly greater in the CR than the PS implant at flexion angles of 45°, 60°, 75°, and 90° KFA, the average at these flexion angles for all loads tested being 246.1 ± 42.1 N and 192.8 ± 54.8 N for CR and PS implants, respectively. CONCLUSIONS/UNASSIGNED:In this biomechanical study, CR TKAs showed less patellofemoral contact force, but more tibiofemoral contact force than PS TKAs. For higher loads across the joint and at increased flexion angles, there was significantly more posterior femur translation in the CR design with a preserved posterior cruciate ligament and therefore significantly less patellofemoral contact area and force than in the PS design. The different effects of loading on implants are an important consideration for physicians as patients with higher load demands should consider the significantly greater patellofemoral contact force and area of the PS over the CR design.

INTRODUCTION/BACKGROUND:The influence of prior colostomy or ileostomy on patients undergoing joint arthroplasty remains poorly understood. Our study aimed to assess whether patients with an ostomy undergoing hip and knee arthroplasties have worse postoperative outcomes and increased rates of revisions. METHOD/METHODS:A single-center, retrospective review of patients with a history of bowel ostomy who underwent a primary total hip arthroplasty (THA), hemiarthroplasty (HA), and total knee arthroplasty (TKA) from 2012 to 2021. A total of 24 THAs, 11 HAs, and 25 TKAs in patients with open small or large bowel stoma were identified. A ten-to-one propensity score match was utilized to establish cohorts with comparable demographics but no prior ostomy procedure. RESULTS:Patients with stomas undergoing elective THA showed greater 90-day ED visits (20.0 vs. 5.0%, P = 0.009), 90-day all-cause readmissions (20.0 vs. 5.0%, P = 0.009), 90-day non-orthopedic readmissions (10.0 vs. 0.5%, P < 0.001), 90-day readmissions for infection (5.0 vs. 0.5%, P = 0.043), all-cause revisions (15.0 vs. 0.5%, P < 0.001), revisions for PJI (5.0 vs. 0%, P = 0.043), and revisions for peri-prosthetic fracture (10.0 vs. 0%, P < 0.001). Patients with stomas undergoing non-elective hip arthroplasties exhibited a longer mean LOS (12.1 vs. 7.0 days, P < 0.001) and increased 90-day all-cause readmissions (40.0 vs. 17.3%, P = 0.034), 90-day orthopedic readmissions (26.7 vs. 6.0%, P = 0.005), all-cause revisions (13.3 vs. 2.0%, P = 0.015), revisions for peri-prosthetic fracture (6.7 vs. 0%, P = 0.002), and revisions for aseptic loosening (6.7 vs. 0%, P = 0.002). There were no significant differences in readmission or revision rates between ostomy patients undergoing TKA and a matched control group. CONCLUSION/CONCLUSIONS:Patients undergoing hip arthroplasties with an open stoma are at an increased risk of hospital encounters and revisions, whereas TKA patients with stomas are not at increased risk of complications. These findings emphasize the importance of recognizing and addressing the unique challenges associated with this patient population.