Faculty Bibliography

BACKGROUND:Use of computer-assisted navigation (CAN) and robotic-assisted (RA) surgery in total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA) both necessitate the use of tracking pins rigidly fixed to the femur and tibia. Although periprosthetic fractures through tracking pin sites are rare, there is a paucity of literature on this potential complication. Therefore, the purpose of this study was to perform a systematic review of the current literature to assess the incidence and clinical outcomes of periprosthetic fractures through tracking pin sites following CAN and RA TKA and UKA. METHODS:A systematic review was performed following PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines using the PubMed, MEDLINE, and Cochrane databases in April 2020. Studies were assessed for the presence of pin site fractures, fracture characteristics, and clinical outcomes. RESULTS:Seventeen clinical studies (5 case series, 1 cohort study, and 11 case reports) involving 29 pin-related fractures were included for review. The overall incidence ranged from 0.06% to 4.8%. The mean time from index arthroplasty to fracture was 9.5 weeks (range, 0 to 40 weeks). The majority of fractures occurred in the femoral diaphysis (59%). Nineteen fractures (66%) were displaced and 10 (34%) were nondisplaced or occult. The majority of cases were atraumatic in nature or involved minor trauma and were typically preceded by persistent leg pain. A transcortical pin trajectory, large pin diameter (>4 mm), diaphyseal fixation, multiple placement attempts, and the use of non-self-drilling, non-self-tapping pins were the most commonly reported risk factors for pin-related periprosthetic fractures following CAN or RA TKA. CONCLUSIONS:Surgeons should maintain a high index of suspicion for pin-related fractures in patients with ongoing leg or thigh pain after CAN or RA TKA in order to avoid fracture displacement and additional morbidity. As CAN and RA TKA have unique complication risks, the debate regarding the value of technology-assisted TKA and its cost-effectiveness continues. LEVEL OF EVIDENCE/METHODS:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Recently, fructosamine has shown promising results in predicting adverse outcomes following total knee arthroplasty. The purpose of this study was to assess the utility of fructosamine to predict adverse outcomes following total hip arthroplasty (THA). A prospective multi-center study involving four institutions was conducted. All primary THA were evaluated for glycemic control using fructosamine levels prior to surgery. Adverse outcomes were assessed at a minimum 1 year from surgery. Primary outcome of interest was periprosthetic joint infection (PJI) based on the International Consensus Meeting (ICM) criteria. Secondary outcomes assessed were superficial infections, readmissions and death. Based on previous studies on the subject, fructosamine levels above 293 µmol/L were used to define inadequate glycemic control. Overall 1212 patients were enrolled in the present study and were available for follow up at a minimum 1 year from surgery. Of those, 54 patients (4.5%) had elevated fructosamine levels (> 293 µmol/L) and these patients were 6.7 times more likely to develop PJI compared to patients with fructosamine levels below 293 µmol/L (p = 0.002). Patients with elevated fructosamine were also associated with more readmissions (16.7% vs. 4.4%, p < 0.007) and a higher mortality rate (3.7% vs. 0.6%, p = 0.057). These associations remained statistically significant in a multi-regression analysis after adjusting for age, comorbidities and length of stay; Adjusted odds ratio were 6.37 (95% confidence interval 1.98-20.49, p = 0.002) for PJI and 2.68 (95% confidence interval 1.14-6.29, p = 0.023) for readmissions. Fructosamine is a good predictor of adverse outcomes in patients undergoing THA and should be used routinely to mitigate morbidity and mortality risk.

The number of revision total knee arthroplasties (TKAs) is greatly increasing. It is important to know how to approach the painful and malfunctioning TKA to determine the etiology and establish surgical plan, and also how to perform a basic revision TKA. Following the conclusion of this chapter, the reader should feel familiar with the full spectrum of treatment for patients who may be indicated for revision TKA.

The COVID-19 pandemic has had unprecedented impact on the United States health care system. One of the consider-ations was the decision to halt elective orthopedic surgery to preserve consumption of scarce resources. However, as the number of COVID-19 cases decrease, there will be discus-sions regarding the modality of resuming elective orthopedic surgery. Ethical considerations will come to the forefront in terms of determining the best course of action, patient selection, resource rationing, and financial implications. These factors will be examined through the lens of the four tenets of bioethics, beneficence, maleficence, autonomy, and justice, to elucidate the best approach in ethically manag-ing elective orthopedic surgery during a global pandemic.

INTRODUCTION/BACKGROUND:Acetylsalicylic acid (aspirin) is a commonly prescribed medication, especially in the age group of individuals who undergo elective total hip arthroplasty (THA). Preoperative discontinuation of aspirin is believed to reduce intraoperative bleeding and other complications, but it may increase the risk of perioperative cardiovascular events. In this study we have sought to evaluate the safety of continuous aspirin treatment in patients undergoing elective THA. MATERIALS AND METHODS/METHODS:This is a retrospective analysis of a consecutive cohort who underwent elective THA in a tertiary medical center between 2011 and 2018. The cohort was divided into two groups-one that received continuous preoperative aspirin treatment and one that did not. Blood loss, peri- and postoperative complications, readmissions, and short- and long-term mortality were compared between groups. RESULTS:Out of 757 consecutive patients (293 males, 464 females) who underwent elective primary THA, 552 were in the "non-aspirin" group and 205 were in the "aspirin" group and were not treated preoperative with other medication affecting hemostasis. Perioperative continuation of aspirin treatment did not significantly increase perioperative bleeding, as indicated by changes in hemoglobin levels (P = 0.72). There were no significant differences in short- and long-term mortality (P = 0.47 and P = 0.4, respectively) or other perioperative complications, such as readmission (P = 0.78), deep or superficial infection (P = 1 and P = 0.47, respectively), and cardiovascular events (none in both groups). CONCLUSION/CONCLUSIONS:Peri-operative continuation of aspirin treatment in patients undergoing elective primary THA did not increase perioperative complications or mortality compared to the non-aspirin-treated patients. The protective effects of aspirin from postoperative thrombotic and cardiovascular events are well documented. The current findings dispute the need to preoperatively withhold aspirin treatment in patients undergoing elective primary THA.

BACKGROUND:The purpose of this multicenter, randomized trial was to determine the optimal dosing regimen of tranexamic acid (TXA) to minimize perioperative blood loss in revision total hip arthroplasty. METHODS:Six centers prospectively randomized 175 patients to 1 of 4 regimens: (1) 1-g intravenous (IV) TXA prior to incision (the single-dose IV group), (2) 1-g IV TXA prior to incision followed by 1-g IV TXA after arthrotomy wound closure (the double-dose IV group), (3) a combination of 1-g IV TXA prior to incision and 1-g intraoperative topical TXA (the combined IV and topical group), or (4) 3 doses totaling 1,950-mg oral TXA (the multidose oral group). Randomization was based on revision subgroups to ensure equivalent group distribution. An a priori power analysis (α = 0.05; β = 0.80) determined that 40 patients per group were required to identify a >1-g/dL difference in postoperative hemoglobin reduction between groups. Per-protocol analysis involved an analysis of variance, Fisher exact tests, and two 1-sided t tests for equivalence. Demographic and surgical variables were equivalent between groups. RESULTS:No significant differences were found between TXA regimens when evaluating reduction in hemoglobin (3.4 g/dL for the single-dose IV group, 3.6 g/dL for the double-dose IV group, 3.5 g/dL for the combined IV and topical group, and 3.4 g/dL for the multidose oral group; p = 0.95), calculated blood loss (p = 0.90), or transfusion rates (14% for the single-dose IV group, 18% for the double-dose IV group, 17% for the combined group, and 17% for the multidose oral group; p = 0.96). Equivalence testing revealed that all possible pairings were statistically equivalent, assuming a >1-g/dL difference in hemoglobin reduction as clinically relevant. There was 1 venous thromboembolism, with no differences found between groups (p = 1.00). CONCLUSIONS:All 4 TXA groups tested had equivalent blood-sparing properties in the setting of revision total hip arthroplasty, with a single venous thromboembolism reported in this high-risk population. Based on the equivalence between groups, surgeons should utilize whichever of the 4 investigated regimens is best suited for their practice and hospital setting. Given the transfusion rate in revision total hip arthroplasty despite TXA utilization, further work is required in this area. LEVEL OF EVIDENCE:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Same-day discharge (SDD) surgery in total hip arthroplasty (THA) has been shown to have similar outcomes to non-SDD THA in select patient populations. Hip resurfacing arthroplasty (HRA) is an alternative to THA for young, active patients, making them ideal candidates for SDD. This study compared the safety and efficacy of non-SDD HRA and SDD HRA for specific postoperative outcomes. An electronic data warehouse query was performed for procedures labeled "hip resurfacing." Data collected included demographics, surgical factors, and quality metrics. Statistical analyses were evaluated using a graphing and statistics software program. Categorical variables were analyzed with chi-square tests and continuous variables with Student's t tests, with P<.05 deemed significant. Sixty-three of 274 total HRAs were enrolled in this SDD HRA protocol. No significant difference was observed between SDD HRA and non-SDD HRA baseline characteristics. On postoperative day 0, 98.41% of SDD HRA recipients were discharged successfully. The SDD HRA recipients had shorter stays, with 1.59% requiring a hospital stay of 2 days or more compared with 56.87% of non-SDD HRA recipients (P<.0001). The non-SDD HRA recipients were found to have shorter surgical times than SDD HRA recipients (104.74 vs 125.51 minutes, P=.01). Rates of infection, periprosthetic fractures, emergency department visits, and hospital readmissions were equivalent (P=.99). Same-day discharge HRA is a safe and effective procedure with similar outcomes to non-SDD HRA regarding infections, fractures, emergency department visits, and readmissions. The major benefit of SDD is a shorter hospital stay that may lead to decreased cost while preserving and enhancing quality of care and patient satisfaction. [Orthopedics. 2020;43(6):e595-e600.].

Objective/UNASSIGNED:The purpose of this study was to investigate whether immediate or delayed tailored DAIR treatment based on microbial species is the optimal treatment for acute post-operative periprosthetic joint infection (PJI). Methods/UNASSIGNED:A multicenter retrospective study was conducted to identify patients who underwent debridement, antibiotics, and implant retention (DAIR) for PJI. Decision analysis modeling was employed to determine the treatment strategy that yielded the greatest patient outcome. Results/UNASSIGNED:316 patients who underwent DAIR for PJI were identified. Conclusion/UNASSIGNED:The decision analysis model determined that the optimal treatment strategy is to perform an immediate DAIR to achieve the greatest QALY outcomes in TKA and THA patients with acute PJI.

Background/UNASSIGNED:Proper sizing of femoral and tibial components has been associated with long-term outcomes and survivorship in simultaneous bilateral total knee arthroplasty (SBTKA) and may be a reason for differences in outcomes between knees. The aim of this study compares post-operative outcomes and revision rates in patients undergoing SBTKA with different component sizes. Methods/UNASSIGNED:A retrospective review was conducted at a single academic institution identifying patients who underwent SBTKA from 2011 to 2019. Inclusion criteria included: primary osteoarthritis, similar pre-operative deformity, and same implant manufacturer. The primary outcome compares pre- and post-op (delta, Δ) Knee Society Score-Knee Score (KSS-KS) and range of motion (ROM) between knees. Secondary outcome measures were all-cause revisions rates, including manipulations under anesthesia and arthroscopy with or without lysis of adhesions. Results/UNASSIGNED:149 patients were identified who met the inclusion criteria: 128 patients had femoral size difference (FSD) of 0, 138 patients had tibial size difference (TSD) of 0, 21 patients with FSD of 1, and 11 patients with TSD of 1. There was no difference in ΔKSS-KS or ΔROM in patients for any FSD or TSD. Revisions for aseptic loosening were greater for TSD 1 compared to TSD 0 (p < 0.001). No other differences in cause of revision were identified. Conclusion/UNASSIGNED:A TSD of 1 may be associated with increased revision rates for aseptic loosening in both smaller and larger sized implants. Surgeons may achieve optimal patient outcomes in SBTKA with proper sized implants through increased awareness of component asymmetry and repeat intraoperative evaluation when asymmetrical measurements occur.