Extended Oral Antibiotic Prophylaxis in High-Risk Patients Substantially Reduces Primary Total Hip and Knee Arthroplasty 90-Day Infection Rate

Identifying 10-year cumulative incidence and risk of revision following total hip arthroplasty in patients with and without a diagnosis of human immunodeficiency virus

INTRODUCTION

Prior studies have shown human immunodeficiency virus (HIV) may be a risk factor for early revision following THA, but little data exists looking at long-term implant survivorship. Therefore, the purpose of this study was to compare the 10-year cumulative incidence rate for revision following THA in patients with and without HIV.

METHODS

A retrospective cohort analysis of patients with HIV undergoing elective THA was conducted using a national database. Patients were stratified into asymptomatic HIV (AHIV) and acquired immune deficiency syndrome (AIDS) cohorts. These patients were propensity-score matched to a group of elective THA patients without HIV based on age, gender, and Charlson Comorbidity Index (CCI) at a 1:2 ratio. Kaplan-Meier and Cox Proportional Hazards Regression Analyses were used to assess cumulative incidence and risk of revisions within 10-years of the index procedure.

RESULTS

In total, 678 patients were at-risk at the 10-year mark. There were no differences in 10-year risk of revision THA, amongst patients with HIV when compared to matched and unmatched controls (p > 0.05 for all). Patients with HIV did have an increased risk of periprosthetic joint infection (PJI) following THA when compared to the unmatched control (p = 0.001).

DISCUSSION

Surgeons and patients can be reassured of comparable 10-year revision rates in patients with and without HIV. However, as these patients are at increased risk for PJI and PPF, especially those with AIDS, when compared to the general population, surgeons should consider PJI prophylactic modalities in this patient population.

Periprosthetic Hip Fracture due to Ballistic Injuries

Periprosthetic hip fractures are a common cause for revision. To date, however, there are no reports of periprosthetic fractures (PFs) in total hip arthroplasty caused by ballistic injury (BI). There are no current recommendations on the management of this pathology in the literature. The objective of this paper is to report on 2 successfully treated cases of PF caused by BIs. Additionally, a brief review of the literature regarding open fracture secondary to BIs is carried out. What we consider appropriate initial and definitive management for these patients is outlined. According to our clinical results and current evidence, adequate management for a BI Vancouver B1 femoral PF consists of early antibiotic therapy, surgical debridement, osteosynthesis with variable angle locking plate, structural allograft, cerclage wires, and negative pressure wound therapy.

Increasing Utilization of Extended Oral Antibiotic Prophylaxis Following Total Knee Arthroplasty From 2010 to 2022

BACKGROUND

Extended oral antibiotic (EOA) prophylaxis has been shown to reduce rates of periprosthetic joint infection in high-risk patients following total knee arthroplasty (TKA). Although national societies' recommendations against their use and clinical efficacy remain controversial, the increase in the literature surrounding EOA prophylaxis suggests a potential change in practice patterns that may warrant the creation of national guidelines. The purpose of this study was to investigate the trends in the utilization of EOA prophylaxis following TKA from 2010 to 2022.

METHODS

Patients who underwent primary or aseptic revision TKA between 2010 and 2022 were identified in a national administrative claims database. Temporal trends in EOA usage following primary or revision TKA were calculated, and secondary analysis examined rates of utilization across demographics, including patients considered at high risk for infection. In total, 1,258,759 primary and 91,530 aseptic revision TKA patients were included in this study.

RESULTS

From 2010 to 2022, EOA prescriptions increased by 321 and 368% following primary and revision TKA, respectively. Rates of utilization among high-risk individuals were similar to those of the general population.

CONCLUSIONS

The use of EOA prophylaxis after TKA has increased significantly since 2010. Given their increasing usage and variation in prescription patterns among patients at high risk of infection, guidelines surrounding their use are necessary to promote antibiotic stewardship while preventing rates of infection.

Benefits and Adverse Events Associated With Extended Antibiotic Use for One Year Following Periprosthetic Joint Infection in Total Knee Arthroplasty: A Prospective Cohort Analysis

BACKGROUND

Periprosthetic joint infections (PJIs) are common and serious complications following knee and hip arthroplasty. Our previous retrospective study suggested extended antibiotics following debridement, antibiotics, and implant retention (DAIR) decreased failure rates and were not associated with increased adverse events (AEs) as compared to a standard 6 weeks of antibiotic therapy. Further, extended antibiotics beyond one year did not provide additional benefits. These observations were tested in this prospective cohort study.

METHODS

A prospective cohort of patients who underwent DAIR for total knee arthroplasty PJI and received primary antibiotics were compared to patients who received primary antibiotics combined with extended antibiotics for one year. Participants had a minimum of 2-year follow-up after the final dose of antibiotics.

RESULTS

A prospective cohort of 79 patients was followed, where 39 participants (52.7%) received primary antibiotics and 35 participants (47.3%) received both primary and extended antibiotics following DAIR. Multivariable time-to-event analyses revealed that extended antibiotic use was an independent predictor of treatment success. Infection-free survival differed significantly between the two treatment regimens, as the hazard of PJI failure was significantly lower for extended antibiotics as compared to primary antibiotics alone (adjusted hazard ratio [HR] = 0.46 [0.24 to 0.87], P = 0.017). The AE rates did not significantly differ between patients treated with primary antibiotics only versus primary combined with extended antibiotics.

CONCLUSIONS

This prospective cohort study supports our previous observations that extended antibiotics for one year were associated with lower failure rates as compared to primary antibiotics alone. Extended antibiotics after primary antibiotics were not found to be associated with increased AEs as compared to only primary antibiotics.

Cutibacterium acnes invades submicron osteocyte lacuno-canalicular networks following implant-associated osteomyelitis

Cutibacterium acnes, part of normal skin flora, is increasingly recognized as an opportunistic pathogen capable of causing chronic prosthetic joint infections (PJI) associated with total hip and knee arthroplasty. However, there is a paucity of literature examining the pathogenesis of C. acnes during PJI. To study this, we developed an implant-associated osteomyelitis murine model in which 8-10-week-old C57BL6 mice were subjected to transtibial implantation of titanium or stainless-steel L-shaped pins contaminated with C. acnes. Postsurgery, mice were killed on Days 14 and 28 for terminal assessments of (1) bacterial load in bone, implant, and internal organs (heart, spleen, kidney, and liver), (2) bone osteolysis (micro-CT), (3) abscess formation (histology), and (4) systematic electron microscopy (EM). In vitro scanning EM (SEM) confirmed that C. acnes can form biofilms on stainless-steel and titanium implants. In mice, C. acnes could persist for 28 days in the tibia. Also, we observed C. acnes dissemination to internal organs. C. acnes chronic osteomyelitis revealed markedly reduced bone osteolysis and abscess formation compared to Staphylococcus aureus infections. Importantly, transmission EM (TEM) investigation revealed the presence of C. acnes within canaliculi, demonstrating that C. acnes can invade the osteocyte lacuno-canalicular networks (OLCN) within bone. Our preliminary pilot study, for the first time, revealed that the OLCN in bone can be a reservoir for C. acnes and potentially provides a novel mechanism of why C. acnes chronic implant-associated bone infections are difficult to treat.

Preventing Infections in Reverse Shoulder Arthroplasty

PURPOSE OF REVIEW

Reverse shoulder arthroplasty (rTSA) is a commonly performed procedure to treat degenerative conditions of the shoulder. With its growing utilization, techniques to reliably diagnose and treat prosthetic joint infection (PJI) have become increasingly important. In this review we outline the current research and prevention methods of prosthetic joint infection in rTSA. This includes preoperative considerations, intraoperative, and postoperative treatment algorithms.

RECENT FINDINGS

There is currently no established standardized protocol for preoperative infection prevention or post operative management. However, recent studies have identified risk factors for infection, as well as successful prevention techniques that can be implemented to minimize infection risk. Although there is no standardized protocol currently utilized to diagnose and treat shoulder PJI, we outline a potential set of preventative measures and postoperative management strategies that clinicians can use to properly diagnose and treat patients with this difficult condition.

Obesity and Primary Total Knee Arthroplasty: The Absolute Versus Relative Risk of Periprosthetic Joint Infection at 15 Years

BACKGROUND

When indicating patients for primary total knee arthroplasty (TKA), surgeons and patients must understand the absolute and relative risks of periprosthetic joint infection (PJI) to make an informed decision. We sought to evaluate the long-term risk of PJI following primary TKA stratified by body mass index (BMI) and PJI-related risk factors.

METHODS

We identified 25,160 primary TKAs performed from 2000 to 2021 at a single institution. Patients were stratified as having 0, 1, or ≥ 2 PJI risk factors (diabetes, chronic kidney disease, nonprimary osteoarthritis, immunosuppression, or active smoking) and into BMI categories. The 15-year cumulative risk of PJI was evaluated by BMI and PJI risk factors.

RESULTS

For the entire cohort, the 15-year absolute risk of PJI was 3%. For patients who did not have PJI risk factors, the absolute risk of PJI at 15 years was 3% in normal weight, 4% in class III obesity, and 4% in class IV obesity. Patients who had class III obesity had a 3-time higher relative risk of PJI when than normal-weight patients (P = 0.01). Among patients who had ≥ 2 PJI risk factors, the absolute risk of PJI at 15 years was 5% in normal weight and 6% in patients who have class III obesity.

CONCLUSIONS

Healthy patients who had class III obesity had a 3-time increased risk of PJI relative to healthy, normal-weight patients; however, the absolute risk of PJI at 15 years after primary TKA was 4% in this group. Surgeons and patients must consider both a 3-time increased relative risk of PJI and a 4% absolute risk of PJI at 15 years after primary TKA when considering surgery in otherwise healthy patients who have BMI ≥ 40.

LEVEL OF EVIDENCE

IV.

Duration of cefazolin prophylaxis did not impact infection risk in a murine model of joint arthroplasty

To minimize periprosthetic joint infection (PJI) risk, some clinicians prescribe extended antibiotic prophylaxis (EAP) following total joint arthroplasty (TJA). Given the limited evidence supporting EAP, we sought to evaluate impact of prophylactic antibiotic duration on PJI risk in a murine TJA model. A titanium prosthesis was implanted into the proximal tibia of 89 mice and inoculated with 102 colony forming units (cfu) of Staphylococcus aureus Xen36. Control mice (n = 20) did not receive antibiotics. Treated mice received either 24 h (n = 35) or 4 days (n = 34) of cefazolin prophylaxis. Cultures were obtained from the prostheses, tibia, femur, and knee tissues 3 weeks after surgery. All mice in the control group developed PJI. Both prophylaxis regimens reduced the rate of PJI relative to the control, with only 2/35 mice in the 24-h cohort (p < 0.0001) and 1/34 in 4-day cohort developing PJI (p < 0.0001). CFU counts from the prostheses, bone and knee tissues were reduced for the 24-h and 4-day prophylaxis cohorts relative to the control (p < 0.0001 for both). There was no difference in rates of PJI or CFU counts between the two prophylaxis cohorts (p = 0.58). Prophylactic cefazolin profoundly reduced rates of PJI in a murine model of TJA in which all control animals developed PJI. Extending cefazolin prophylaxis duration from 24 h to 4 days did not result in improved PJI rates or decreased bacterial loads in infected cases. While these results strongly support use of antibiotic prophylaxis for TJA, EAP did not appear to add benefit in the described mouse model.

Impact of Extended Prophylactic Antibiotics on Risk of Prosthetic Joint Infection in Primary Total Hip Arthroplasty: A Matched Cohort Analysis

BACKGROUND

Extended oral prophylactic antibiotics have been increasingly used in arthroplasty with the goal of reducing the risk of prosthetic joint infection (PJI). While a reduction in the rate of PJI has been noted with extended oral antibiotic regimens in high-risk patients, no large database study has assessed infection risk after primary total hip arthroplasty among well-balanced cohorts receiving and not receiving postoperative extended oral antibiotics.

METHODS

A retrospective cohort study was conducted using a national database, TriNetX, to identify patients who underwent primary total hip arthroplasty. This cohort was stratified by oral antibiotic prescription within one day of procedure. A one-to-one propensity score matching based on age, sex, class of obesity, and medical comorbidities was conducted. Outcomes explored in this study were 90-day risk of PJI, superficial skin infection, deep skin infection, and all-cause revision.

RESULTS

90-day postoperative infection complications of PJI were higher in the group receiving antibiotics (hazard ratio: 1.83, P -value = 0.012). Other complications such as superficial skin infection, deep skin infection, and all-cause revision showed no statistically significant differences.

CONCLUSION

This database analysis of 5,476 patients demonstrated no decrease in complications of PJI, superficial or deep skin infection, or revision at 90 days. Future randomized controlled trials are needed to evaluate the efficacy of extended oral antibiotics.

LEVEL OF EVIDENCE

III.

Extended Prophylactic Antibiotics for Primary and Aseptic Revision Total Joint Arthroplasty: A Meta-Analysis

BACKGROUND

There is growing interest in extended antibiotic prophylaxis (EAP) following total joint arthroplasty (TJA); however, the benefit of EAP remains controversial. For this investigation, both oral and intravenous antibiotic protocols were included in the EAP group.

METHODS

The Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials, PubMed, MEDLINE, Web of Science, Ovid Embase, Elton B. Stephens CO, and Cumulative Index to Nursing and Allied Health Literature were queried for literature comparing outcomes of primary and aseptic revision total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients who were treated with either ≤24 hours of postoperative antibiotic prophylaxis (standard of care [SoC]) or >24 hours of EAP. The primary outcome was periprosthetic joint infection (PJI). A pooled relative-risk random-effects Mantel-Haenszel model was implemented to compare cohorts.

RESULTS

There were 18 studies with a total of 19,153 patients included. There was considerable variation in antibiotic prophylaxis protocols with first-generation cephalosporins being the most commonly implemented antibiotic for both groups. Patients treated with EAP were 35% less likely to develop PJI relative to the SoC (P = .0004). When examining primary TJA, patients treated with EAP were 39% and 40% less likely to develop a PJI for TJA (P = .0008) and THA (P = .02), respectively. There was no significant difference for primary TKA (P = .17). When examining aseptic revision TJA, EAP led to a 36% and 47% reduction in the probability of a PJI for aseptic revision TJA (P = .007) and aseptic revision TKA (P = .008), respectively; there was no observed benefit for aseptic revision THA (P = .36).

CONCLUSIONS

This meta-analysis demonstrated that patients treated with EAP were less likely to develop a PJI relative to those treated with the SoC for all TJA, primary TJA, primary THA, aseptic revision TJA, and aseptic revision TKA. There was no significant difference observed between EAP and SoC for primary TKA or aseptic revision THA.

Should All Patients Receive Extended Oral Antibiotic Prophylaxis? Defining Its Role in Patients Undergoing Primary and Aseptic Revision Total Joint Arthroplasty

BACKGROUND

Prior studies have demonstrated reduced periprosthetic joint infection (PJI) rates following extended oral antibiotics (EOAs) for high-risk patients undergoing primary total joint arthroplasty (TJA). This study compared 3-month PJI rates in all patients undergoing primary or aseptic revision TJA with or without EOA prophylaxis.

METHODS

In total, 2,982 consecutive primary (n = 2,677) and aseptic revision (n = 305) TJAs were performed by a single, fellowship-trained arthroplasty surgeon from 2016 to 2022 were retrospectively reviewed. Beginning January 2020, all patients received 7 days of 300 mg oral cefdinir twice daily immediately postoperatively. Rates of PJI at 3 months were compared between patients who received or did not receive EOA.

RESULTS

Rates of PJI at 3 months in patients undergoing primary and aseptic revision TJA were significantly lower in those receiving EOA prophylaxis compared to those who did not (0.41 versus 1.13%, respectively; P = .02). After primary TJA, lower PJI rates were observed with EOA prophylaxis utilization (0.23 versus 0.74%, P = .04; odds ratio [OR] 3.85). Following aseptic revision TJA, PJI rates trended toward a significant decrease with the EOA compared to without (1.88 versus 4.83%, respectively; P = .16; OR 2.71).

CONCLUSIONS

All patients undergoing primary or aseptic revision TJA who received EOA prophylaxis were 3.85 and 2.71 times less likely, respectively, to develop PJI at 3 months compared to those without EOA. Future studies are needed to determine if these results are maintained at postoperative time periods beyond 3 months following primary TJA.

LEVEL OF EVIDENCE

III, Retrospective review.

Obesity and Primary Total Hip Arthroplasty: The Absolute versus Relative Risk of Periprosthetic Joint Infection at 15 Years

BACKGROUND

To make an informed decision about total hip arthroplasty (THA), surgeons and patients need to understand the absolute and relative risks of periprosthetic joint infection (PJI). We sought to evaluate the long-term risk of PJI following primary THA stratified by body mass index (BMI) and PJI-related risk factors.

METHODS

We identified 21,550 primary THAs performed from 2000 to 2021 at a single institution. Patients were stratified as having 0, 1, or ≥ 2 PJI risk factors (diabetes, chronic kidney disease, nonprimary osteoarthritis, immunosuppression, or active smoking) and into BMI categories. The 15-year cumulative risk of PJI was evaluated by BMI and PJI risk factors.

RESULTS

For the entire cohort, the 15-year absolute risk of PJI was 2%. For patients who did not have PJI risk factors, the absolute risk of PJI at 15 years was 1% in normal weight, 2% in class III obesity, and 4% in class IV obesity. Patients who had class III and IV obesity had a 3-times and 9-times higher relative risk of PJI, respectively (P = .03, P < .001). Among patients who had ≥ 2 PJI risk factors, the absolute risk of PJI at 15 years was 2% in normal weight, 4% in class III obesity, and 18% in class IV obesity.

CONCLUSIONS

Healthy patients who had class III and IV obesity had a 3-times and 9-times increased risk of PJI at 15 years relative to normal weight patients. However, the absolute risk of PJI at 15 years was 2 and 4%, respectively. Given emerging data questioning whether BMI modification decreases PJI risk, surgeons and patients must consider both a 3-times to 9-times increased relative risk of PJI and a 2 to 4% absolute risk of PJI at 15 years for healthy patients who had a BMI ≥ 40.

LEVEL OF EVIDENCE

IV.

Not so Fast: Extended Oral Antibiotic Prophylaxis Does Not Reduce 90-Day Infection Rate Following Joint Arthroplasty

BACKGROUND

Periprosthetic joint infection (PJI) is a devastating complication following both total hip (THA) and knee (TKA) arthroplasty. Extended oral antibiotic (EOA) prophylaxis has been reported to reduce PJI following TJA in high-risk patients. The purpose of this study was to determine if EOA reduces PJI in all-comers and high-risk THA and TKA populations.

METHODS

This is a retrospective cohort study, including 4,576 patients undergoing primary THA or TKA at a single institution from 2018 to 2022. Beginning in 2020, EOA prophylaxis was administered for 10 days following THA or TKA at our institution. Patients were separated into 2 cohorts (1,769 EOA, 2,807 no EOA) based on whether they received postoperative EOA. The 90-day and 1-year outcomes, with a focus on PJI, were then compared between groups. A subgroup analysis of high-risk patients was also performed.

RESULTS

There was no difference in 90-day PJI rates between cohorts (EOA 1 versus no EOA 0.8%; P = .6). The difference in the rate of PJI remained insignificant at 1 year (EOA 1 versus no EOA 1%; P = .9). Similarly, our subgroup analysis of high-risk patients demonstrated no difference in postoperative PJI between EOA (n = 254) and no EOA (n = 396) (0.8 versus 2.3%, respectively; P = .2). Reassuringly, we also found no differences in the incidence of Clostridium difficile infection (EOA 0.1 versus no EOA 0.1%; P > .9) or in antibiotic resistance among those who developed PJI within 90 days (EOA 59 versus no EOA 83%; P = .2).

CONCLUSIONS

With the numbers available for analysis, EOA prophylaxis was not associated with PJI risk reduction following primary TJA when universally deployed. Furthermore, among high-risk patients, there was no statistically significant difference. While we did not identify increased antibiotic resistance or Clostridium difficile infection, we cannot recommend wide-spread adoption of EOA prophylaxis, and clarification regarding the role of EOA, even in high-risk patients, is needed.

Patients Who Have Prior Solid Organ Transplants Have Increased Risk of 10-Year Periprosthetic Joint Infection Revision Following Primary Total Knee Arthroplasty: A Propensity-Matched Analysis

BACKGROUND

Total knee arthroplasty (TKA) for solid organ transplant (SOT) patients is becoming more prominent as life expectancy in this population increases. However, data on long-term (10 year) implant survivorship in this cohort are sparse. The purpose of this study was to compare 90-day, 2-year, 5-year, and 10-year implant survivability following primary TKA in patients who did and did not have prior SOT.

METHODS

The PearlDiver database was utilized to query patients who underwent unilateral elective TKA with at least 2 years of active follow-up. These patients were stratified into those who had a SOT before TKA and those who did not. The SOT cohort was propensity-matched to control patients based on age, sex, Charlson Comorbidity Index, and obesity in a 1:2 ratio. Cumulative incidence rates and hazard ratios (HRs) were compared between the SOT, matched, and unmatched cohorts.

RESULTS

No difference was observed in 10-year cumulative incidence and risk of all-cause revision surgery in TKA patients with prior SOT when compared to matched and unmatched controls. Compared to the matched control, the SOT cohort had no difference in the risk of revision when stratified by indication and timing. However, when compared to the unmatched control, patients who had prior SOT had a higher risk for revision due to periprosthetic joint infection at 10 years (HR: 1.80; 95% confidence interval: 1.17 to 2.76) as well as all-cause revision within 90 days after TKA (HR: 1.93; 95% confidence interval: 1.10 to 3.36).

CONCLUSIONS

Prior SOT patients have higher rates of all-cause revision within 90 days and periprosthetic joint infection within 10 years when compared to the general population, likely associated with the elevated number of comorbidities in SOT patients and not the transplant itself. Therefore, these patients should be monitored in the preoperative and early postoperative settings to optimize their known comorbidities.

Oral Postoperative Antibiotic Prophylaxis for Outpatient Total Hip and Knee Arthroplasty: Describing Current Practices

BACKGROUND

Despite an increase in outpatient total hip arthroplasty (THA) and total knee arthroplasty (TKA), large-scale data are lacking on current practice for antibiotic prophylaxis prescribing. We aimed to describe current oral antibiotic prophylaxis practices nationally for outpatient THA and TKA.

METHODS

This nationwide retrospective cohort study included primary outpatient THA or TKA procedures in patients aged 18 to 64 years from 2018 to 2021 using a national claims database. Oral antibiotic prescriptions filled perioperatively (defined as 5 days before to 3 days after surgery) were extracted; these were categorized and assumed to represent postoperative prophylaxis. Multivariable logistic regression measured associations between patient and surgery characteristics and perioperative oral antibiotic prophylaxis. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) are reported.

RESULTS

Oral antibiotic prescriptions were filled in 16.5% of 73,015 outpatient THA and TKA (18.4% of 24,857 THAs, 15.5% of 48,158 TKAs) procedures. Prescriptions were most often for cephalosporins (74.3%), with cephalexin (52.8%), and cefadroxil (19.1%) being the most common. Non-cephalosporin antibiotics prescribed were mainly clindamycin (6.8%), sulfamethoxazole-trimethoprim (6.7%), and doxycycline (6.2%). The odds of receiving oral antibiotic prophylaxis were higher for THA compared to TKA (OR 1.13, 95% CI 1.09 to 1.18, P < .001) and in the presence of obesity, diabetes, and autoimmune conditions (OR 1.08 to 1.13, P < .001 to .01). Ambulatory surgery center procedures also had significantly increased odds of prophylaxis compared to hospital-based outpatient surgeries (OR 2.62, 95% CI 2.51 to 2.73, P < .001). Additionally, regional and time-based variations were noted.

CONCLUSIONS

Perioperative oral antibiotic prophylaxis prescriptions were filled in only 16.5% of outpatient THA and TKA cases, with variation in the type of antibiotic prescribed. The receipt of any prophylaxis and specific medications was associated with demographic, clinical, and procedure-related characteristics. Follow-up research will evaluate associations with infection risk reduction.

Can ChatGPT Answer Patient Questions Regarding Total Knee Arthroplasty?

The internet has introduced many resources frequently accessed by patients prior to orthopaedic visits. Recently, Chat Generative Pre-Trained Transformer, an artificial intelligence-based chat application, has become publicly and freely available. The interface uses deep learning technology to mimic human interaction and provide convincing answers to questions posed by users. With its rapidly expanding usership, it is reasonable to assume that patients will soon use this technology for preoperative education. Therefore, we sought to determine the accuracy of answers to frequently asked questions (FAQs) pertaining to total knee arthroplasty (TKA).Ten FAQs were posed to the chatbot during a single online interaction with no follow-up questions or repetition. All 10 FAQs were analyzed for accuracy using an evidence-based approach. Answers were then rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification."Of the 10 answers given by the chatbot, none received an "unsatisfactory" rating with the majority either requiring minimal (5) or moderate (4) clarification. While many answers required nuanced clarification, overall, answers tended to be unbiased and evidence-based, even when presented with controversial subjects.The chatbot does an excellent job of providing basic, evidence-based answers to patient FAQs prior to TKA. These data were presented in a manner that will be easily comprehendible by most patients and may serve as a useful clinical adjunct in the future.

Psoriasis Is a Risk Factor for Surgical Site Infection After Primary TKA

BACKGROUND

The relationship between psoriasis and complications after primary TKA is not well defined. Current studies are limited to small, single-center studies evaluating fewer than 150 patients with psoriasis, with some studies reporting an increased risk of surgical site infection (SSI) and another reporting no associated risk. There is a need to reevaluate the risk of psoriasis and postoperative complications, including SSI, to better risk-stratify and guide practice in this patient population.

QUESTIONS/PURPOSES

(1) Compared with patients without psoriasis, after accounting for potential confounders such as age, insurance, and comorbidities, do patients with psoriasis have a higher odds of superficial SSI after primary TKA? (2) Do patients with psoriasis have a higher odds of deep SSI after primary TKA?

METHODS

Patients 18 years or older who underwent unilateral, primary TKA between 2015 and 2019 were identified in the PearlDiver database (n = 490,722). Patients with rheumatoid, septic, or posttraumatic arthritis were excluded, as well as patients with bone neoplasias (n = 188,557). Additionally, patients with less than 2 years of follow-up (n = 53,673) were excluded. In all, 248,492 patients were included in this study; 0.4% (1078) were in the psoriasis group and 99% (247,414) were in the control group. Overall 2-year superficial and deep SSI rates were stratified and compared between patients with psoriasis and a control group of patients who did not have psoriasis as the primary outcome. Secondary outcomes included the odds of undergoing an aseptic revision or manipulation under anesthesia.

RESULTS

In the multivariable analysis, which controlled for potential confounders such as age, sex, Elixhauser comorbidity index, hypertension, diabetes mellitus, and liver disease, the odds of SSI-either superficial or deep-remained higher for patients with psoriasis (OR 1.74 [95% confidence interval 1.03 to 2.96]; p = 0.04). When focusing on superficial infections in the multivariable analysis, patients with psoriasis had a higher odds of superficial SSI than those in the control group (OR 2.83 [95% CI 1.26 to 6.34]; p = 0.01). The odds of deep SSI were not different between the two cohorts in our multivariable analysis (OR 1.32 [95% CI 0.66 to 2.66]; p = 0.43). Patients with psoriasis did not have an increased odds of undergoing an aseptic revision (OR 0.79 [95% CI 0.48 to 1.32]; p = 0.38) or manipulation under anesthesia (OR 0.74 [95% CI 0.52 to 1.06]; p = 0.10).

CONCLUSION

Patients with psoriasis had higher overall rates of SSI at 2 years of follow-up than patients without psoriasis. Our findings suggest that psoriasis is a risk factor for superficial SSI after primary TKA and is an important comorbidity for surgeons to consider before surgery. Further research is needed to assess the role of adjunctive interventions in patients with psoriasis to mitigate the elevated odds of superficial SSI.

LEVEL OF EVIDENCE

Level II, prognostic study.

Additional doses of prophylactic antibiotics post-arthroplasty: Are there any benefits?

Guidelines for prophylactic antibiotic administration in total joint replacement vary considerably in terms of drug, dosage, route of administration and duration of cover. Despite the range of treatment options available, infection remains the most common reason for arthroplasty failure in the decades following a procedure, simultaneously increasing health care costs and lowering patient satisfaction considerably. This work aims to evaluate whether there are benefits to administering further doses of antibiotic post-arthroplasty, in addition to the recommendations of current protocols. We present a review of evidence surrounding infection rates in a variety of prophylactic regimens, and weigh this against further considerations such as cost to the patient and risks of nephrotoxicity. In summary, the available evidence does not suggest a benefit to administering additional doses post-arthroplasty in most cases. However, further doses may benefit those deemed at high risk of infection, or those in areas of high methicillin-resistant Staphylococcus aureus prevalence.

Addition of gentamicin for antibiotic prophylaxis in hip hemiarthroplasty does not decrease the rate of surgical site infection

BACKGROUND

The addition of Gram-negative coverage to antibiotic prophylaxis protocols prior to elective total hip arthroplasty (THA) has been reported to reduce periprosthetic joint infection (PJI). However, it is unknown whether adding a Gram-negative-targeted antibiotic agent improves outcomes in the trauma population. This study aimed to investigate whether the addition of a single, pre-operative dose of Gentamicin is associated with lower rates of PJI in patients undergoing hemiarthroplasty (HA) as treatment for a hip fracture.

METHODS

We retrospectively reviewed cases of patients who underwent HA as treatment for a hip fracture from January 2011 to January 2022, and had a minimum 1-year of follow-up. Patients were divided into two groups based on the antibiotic prophylaxis they received during surgery: cefazolin (control group) or cefazolin with addition of Gentamicin (case group). The primary outcome was the rate of surgical site infections (SSI), and secondary outcomes included rates of prosthetic joint infection (PJI) and superficial SSIs.

RESULTS

The final study population consisted of 1521 patients. 336 patients (22.1%) were in the case group and 1185 (77.9%) patients were in the control group. Rates of SSI were comparable between the groups (3.8% for the case group vs. 2.8% in the control group, p = 0.34). This held true for both PJIs (3.5 vs. 2.5%, p = 0.3) and superficial SSIs (0.29 vs. 0.33%, p = 0.91). The distribution of the causing pathogen was similar between the groups (p = 0.84). Gentamicin susceptibility rates of the Gram-negative bacteria associated with PJI were similar between the cohorts (p = 0.51).

CONCLUSIONS

The addition of a single, pre-operative dose of Gentamicin to the antibiotic prophylaxis protocol of patients undergoing HA as treatment for a hip fracture was not associated with lower rates of SSI, PJI or superficial SSI. The findings of this study indicate that the prophylactic benefits of Gentamicin may not apply to HA as they do to THA.

How Many Patients Qualify for Extended Oral Antibiotic Prophylaxis Infection Following Primary and Revision Hip and Knee Arthroplasties?

Extended oral antibiotic prophylaxis (EOAP) has been suggested to reduce rates of periprosthetic joint infection (PJI) postoperatively after total joint arthroplasty (TJA). The purpose of this multicenter study is to define how many TJA patients are considered high risk for developing PJI based on published EOAP criteria and determine whether this status is associated with socioeconomic or demographic factors. All primary and aseptic revision TJAs performed in 2019 at three academic medical centers were reviewed. High-risk status was defined based on prior published EOAP criteria. Area deprivation index (ADI) was calculated as a measure of socioeconomic status. Data were reported as means with standard deviation. Both overall and institutional differences were compared. Of the 2,511 patients (2,042 primary and 469 revision) in this cohort, 73.3% met criteria for high risk (primary: 72.9% [1,490] and revision: 74.6% [350]). Patient's race or age did not have a significant impact on risk designation; however, a larger proportion of high-risk patients were women (p = 0.002) and had higher Elixhauser scores (p < 0.001). The mean ADI for high-risk patients was higher (more disadvantaged) than for standard-risk patients (64.0 [20.8] vs. 59.4 [59.4]) (p < 0.001). Over 72% of primary and revision TJA patients at three medical centers met published criteria for EOAP. These patients were more often women, had more comorbidities, and lived in more disadvantaged areas. Our findings suggest that most patients qualify for EOAP, which may call for more stringent criteria on who would benefit extended antibiotic prophylaxis.

Association between radiographic soft-tissue thickness and increased length of stay, operative time, and infection rate after reverse shoulder arthroplasty

BACKGROUND

Reverse shoulder arthroplasty (RSA) is a widely performed surgical procedure to address various shoulder pathologies. Several studies have suggested that radiographic soft-tissue thickness may play a role in predicting complications after orthopedic surgery, but there have been limited studies determining the use of radiographic soft-tissue thickness in RSA. The purpose of this study was to evaluate whether radiographic soft-tissue thickness could predict clinical outcomes after RSA and compare the predictive capabilities against body mass index (BMI). We hypothesized that increased radiographic shoulder soft-tissue thickness would be a strong predictor of operative time, length of stay (LOS), and infection in elective RSA.

MATERIAL AND METHODS

A retrospective review of patients undergoing RSA at an academic institution was conducted. Preoperative radiographic images were evaluated including measurements of the radius from the humeral head center to the skin (HS), deltoid radius-to-humeral head radius ratio (DHR), deltoid size, and subcutaneous tissue size. Different correlation coefficients were used to analyze various types of relationships, and the strength of these associations was classified based on predefined boundaries. Subsequently, multivariable linear and logistic regressions were performed to determine whether HS, DHR, deltoid size, and subcutaneous tissue size could predict LOS, operative time, or infection while controlling for patient factors.

RESULTS

HS was the most influential factor in predicting both operative time and LOS after RSA, with strong associations indicated by standardized β coefficients of 0.234 for operative time and 0.432 for LOS. Subcutaneous tissue size, deltoid size, and DHR also showed stronger predictive values than BMI for both outcomes. In terms of prosthetic joint infection, HS, deltoid size, and DHR were significant predictors, with HS demonstrating the highest predictive power (Nagelkerke R2 = 0.44), whereas BMI did not show a statistically significant association with infection. Low event counts resulted in wide confidence intervals for odds ratios in the infection analysis.

CONCLUSION

Greater shoulder soft-tissue thickness as measured with concentric circles on radiographs is a strong predictor of operative time, LOS, and postoperative infection in elective primary RSA patients.

Sex-related differences in periprosthetic joint infection research

Introduction: Periprosthetic joint infections (PJIs) have emerged as a focal point in the realm of orthopedics, garnering widespread attention owing to the escalating incidence rates and the profound impact they impose on patients undergoing total joint arthroplasties (TJAs). Year after year, there has been a growing trend in the analysis of multiple risk factors, complication rates, and surgical treatments in the field. This study aims to illuminate the status of the sex-related differences in periprosthetic joint infections and advance research in this field. Methods: A systematic review was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. The final reference list comprised longitudinal studies (both retrospective and prospective) and randomized controlled trials. A sex-based analysis was conducted to assess differences between males and females. Results: A total of 312 studies were initially identified through online database searches and reference investigations. Nine studies were subsequently included in the review. Eight out of nine studies examined the risk of developing PJI after total joint replacement. Notably, only half of these studies demonstrated a statistically significant value, with a p  value  < 0.05 , indicating a higher risk of infectious complications in males compared to females. Conclusion: According to the current literature, there appears to be a propensity for males to develop periprosthetic joint infection after total joint arthroplasty at a higher rate than the female population. Enhancing sex-related analysis in this field is imperative for gathering more robust evidence and insights.

Early Periprosthetic Femur Fractures After Primary Cementless Total Hip Arthroplasty: High Risk of Periprosthetic Joint Infection and Subsequent Reoperation

BACKGROUND

Periprosthetic femur fracture (PFF) following total hip arthroplasty (THA) is a leading cause of early reoperation. The objective of this study was to compare rates of periprosthetic joint infection (PJI) and reoperation following PFFs occurring early postoperatively to those that occurred late.

METHODS

We retrospectively identified 173 consecutive surgically managed PFFs following primary THA. Cases were categorized as "early" if they occurred within 90 days of THA (n = 117) or "late" if they occurred following the initial 90 days (n = 56). Mean age at time of PFF was 68 years (range, 26 to 96) and 60% were women. Mean body mass index was 29 (range, 16 to 52). Mean follow-up was 2 years (range, 0 to 13). Kaplan-Meier survival analysis estimated cumulative incidences of PJI and reoperation.

RESULTS

Early PFFs had higher 2-year cumulative incidence of PJI (11% versus 0%, P < .001) and reoperation (24% versus 13%, P = .110). Following early PFF, 27 patients required reoperation (ie, 13 for PJI, 5 for instability, 2 for re-fracture, 2 for painful hardware, 2 for non-union, 1 for adverse local tissue reaction, 1 for aseptic loosening, and 1 for leg-length discrepancy). Following late PFF, 5 patients required reoperation (ie, 3 for instability, 1 for re-fracture, and 1 for non-union).

CONCLUSIONS

There are greater incidences of PJIs and overall reoperations following early PFFs compared to late PFFs after THA. In addition to focusing efforts on prevention of early PFFs, surgeons should consider antiseptic interventions to mitigate the increased risk of PJI after treatment of early PFF.

Suppressive Antibiotic Therapy After Debridement, Antibiotics, and Implant Retention is Well-Tolerated Without Inducing Resistance: A Multicenter Study

BACKGROUND

Suppressive antibiotic therapy (SAT) after total joint arthroplasty (TJA) debridement, antibiotics, and implant retention (DAIR) maximizes reoperation-free survival. We evaluated SAT after DAIR of acutely infected primary TJA regarding: 1) adverse drug reaction (ADR)/intolerance; 2) reoperation for infection; and 3) antibiotic resistance.

METHODS

Patients who underwent total knee arthroplasty (TKA) or total hip arthroplasty (THA) DAIR for acute periprosthetic joint infection at two academic medical centers from 2015 to 2020 were identified (n = 115). Data were collected on patient demographics, infecting organisms, antibiotics, ADR/intolerances, reoperations, and antibiotic resistances. Median SAT duration was 11 months. Stepwise multivariate logistic regressions were used to identify covariates significantly associated with outcomes of interest.

RESULTS

There were 11.1 and 16.3% of TKA and THA DAIR patients, respectively, who had ADR/intolerance to SAT. Patients prescribed trimethoprim/sulfamethoxazole (P = .0014) or combination antibiotic therapy (P = .0169) after TKA DAIR had increased risk of ADR/intolerance. There was no difference in reoperation-free survival between TKA (83.3%) and THA (65.1%) DAIR (P = .5900) at mean 2.8-year follow-up. Risk of reoperation for infection was higher among TKA Staphylococcus aureus infections (P = .0004) and lower with increased SAT duration (P < .0450). The optimal duration of SAT was nearly 2 years. No cases of antibiotic resistance developed due to SAT.

CONCLUSIONS

Consider SAT after TJA DAIR due to improved reoperation-free survival and favorable safety profile. Prolonged SAT did not induce antibiotic resistance. Use trimethoprim/sulfamethoxazole with caution because of the increased likelihood of ADR/intolerance.

LEVEL OF EVIDENCE

Therapeutic Level III.

How are Oral Antibiotics Being Used in Total Joint Arthroplasty? A Review of the Literature

While the role and benefit of perioperative intravenous (IV) antibiotics in patients undergoing total joint arthroplasty (TJA) is well-established, oral antibiotic use in TJA remains a controversial topic with wide variations in practice patterns. With this review, we aimed to better educate the orthopedic surgeon on when and how oral antibiotics may be used most effectively in TJA patients, and to identify gaps in the literature that could be clarified with targeted research. Extended oral antibiotic prophylaxis (EOAP) use in high-risk primary, aseptic revision, and exchange TJA for infection may be useful in decreasing periprosthetic joint infection (PJI) rates. When prescribing oral antibiotics either as EOAP or for draining wounds, patient factors, type of surgery, and type of infectious organisms should be considered in order to optimally prevent and treat PJI. It is important to maintain antibiotic stewardship by administering the proper duration, dose, and type of antibiotics and by consulting infectious disease when necessary.

Total hip arthroplasty in patients with colostomy: impact on inpatient complications, hospital costs, and length of stay

INTRODUCTION

The presence of permanent end-colostomy is traditionally thought of as a risk factor for complications following orthopedic joint replacement; however, literature supporting this association is scarce. This study aims to discern how length of stay, cost of stay, and inpatient complications following total hip arthroplasty (THA) are impacted by presence of colostomy.

METHODS

Data from the National Inpatient Sample was analyzed by International Classification of Diseases, 10th Revision, Clinical Modification regarding THA in patients with and without end-colostomy. Unmatched and matched analyses comparing length of stay, cost of stay, and post-operative adverse outcomes between the two groups were conducted. In the unmatched analysis, 445 THA patients with colostomy were compared to 367,449 THA patients without colostomy. The colostomy patients were then matched for age, sex, race, diabetes, obesity, and the matched groups consisted of 445 patients with and 425 patients without colostomy, respectively.

RESULTS

Compared to the THA without colostomy group, the colostomy group was significantly older, had longer hospital stays, and greater cost of stay. When matched for age and comorbidities, length of hospital stay (p < 0.001) and cost of stay (p = 0.002) remained significantly higher. The colostomy group was at significantly increased risk for periprosthetic fracture, dislocation, and infection compared to all THA patients. When matched for age and common comorbidities, the colostomy group had significantly higher risk in only periprosthetic dislocation [p = 0.003, OR 11.8 (1.6-4.6, 95% CI)] and periprosthetic infection [p < 0.05, OR 2.7 (0.97-7.7 95% CI)].

CONCLUSION

Patients with colostomy are at risk of longer hospital courses and greater incurred costs following THA compared to patients without colostomy. They are additionally at significantly increased risk of periprosthetic dislocation and periprosthetic infection, warranting treatment as high-risk patients.

STUDY DESIGN

Retrospective cohort study.

Assessing ChatGPT Responses to Common Patient Questions Regarding Total Hip Arthroplasty

BACKGROUND

The contemporary patient has access to numerous resources on common orthopaedic procedures before ever presenting for a clinical evaluation. Recently, artificial intelligence (AI)-driven chatbots have become mainstream, allowing patients to engage with interfaces that supply convincing, human-like responses to prompts. ChatGPT (OpenAI), a recently developed AI-based chat technology, is one such application that has garnered rapid growth in popularity. Given the likelihood that patients may soon call on this technology for preoperative education, we sought to determine whether ChatGPT could appropriately answer frequently asked questions regarding total hip arthroplasty (THA).

METHODS

Ten frequently asked questions regarding total hip arthroplasty were posed to the chatbot during a conversation thread, with no follow-up questions or repetition. Each response was analyzed for accuracy with use of an evidence-based approach. Responses were rated as "excellent response not requiring clarification," "satisfactory requiring minimal clarification," "satisfactory requiring moderate clarification," or "unsatisfactory requiring substantial clarification."

RESULTS

Of the responses given by the chatbot, only 1 received an "unsatisfactory" rating; 2 did not require any correction, and the majority required either minimal (4 of 10) or moderate (3 of 10) clarification. Although several responses required nuanced clarification, the chatbot's responses were generally unbiased and evidence-based, even for controversial topics.

CONCLUSIONS

The chatbot effectively provided evidence-based responses to questions commonly asked by patients prior to THA. The chatbot presented information in a way that most patients would be able to understand. This resource may serve as a valuable clinical tool for patient education and understanding prior to orthopaedic consultation in the future.

Examining the Efficacy of Drain Tip Cultures in Predicting Postoperative Surgical Site Infections in Hip Arthroplasty: A 15-Year Retrospective Study

Background Postoperative surgical site infections (SSIs) are a significant complication of surgical procedures, leading to increased morbidity, prolonged hospital stays, and substantial healthcare costs; however, the use of drain tip cultures to diagnose SSIs in patients is controversial. The objective of this study was to evaluate the efficacy of drain tip cultures for the prediction of postoperative SSIs in patients recovering from hip arthroplasty. Methodology The data were collected from 1204 patients who underwent hip arthroplasty procedures over 15 years, and statistical analysis was performed to evaluate the diagnostic value of drain tip culture in determining surgical site infection. We also used these data to evaluate whether preexisting conditions such as hypertension or diabetes affected the probability of a patient getting an SSI. Results Drain tip cultures were positive in 12 of 1,112 cases of primary hip arthroplasty, but only one of these 12 patients was ultimately diagnosed with an SSI (sensitivity, 12.5%; specificity, 99.0%; p = 0.0834). Results from postoperative drain tip cultures performed in patients undergoing revision arthroplasty included two false positives and three false negatives; interestingly, no true positives were detected in any of the revision arthroplasty cases we evaluated (sensitivity, 0％; specificity, 97.8％; p = 0.9355). Conclusion Our results indicate that drain tip cultures have no statistically significant predictive value for the diagnosis of postoperative SSIs and thus should not be used as a primary diagnostic or predictive tool for SSIs. We recommend exploring other diagnostic tools for the postoperative diagnosis of SSIs. Standardized guidelines should therefore be established to improve the predictive value of the different methods.

The Use of Oral Antibiotics After Total Joint Arthroplasty: A Critical Analysis Review

» There is conflicting and insufficient evidence that extended oral antibiotic (EOA) therapy prevents infection in high-risk patients undergoing primary total joint arthroplasty (TJA), limiting recommendation for or against the practice.» In the case of aseptic revision TJA, the evidence is also conflicting and limited by underlying confounders, preventing recommendation for use of EOA.» There is fair evidence that use of EOA after debridement antibiotic therapy and implant retention of the prosthesis prolongs infection-free survival, but randomized controlled trials are needed. On the other hand, there is strong evidence that patients undergoing 2-stage revision should receive a period of suppressive oral antibiotics after the second stage.» The optimal duration of EOA in primary TJA, aseptic revision, and debridement antibiotic therapy and implant retention of the prosthesis is unknown. However, there is strong evidence that 3 months of EOA suppression may be appropriate after reimplantation as part of 2-stage exchange arthroplasty.» Complications secondary to EOA are reported to be between 0% and 13.7%, yet are inconsistently reported and poorly defined. The risks associated with antibiotic use, including development of antimicrobial resistance, must be weighed against a possible decrease in infection rate.

10-Year Cumulative Incidence and Indications for Revision Total Knee Arthroplasty Among Patients Who Have Sickle Cell Disease

BACKGROUND

Literature regarding total knee arthroplasty (TKA) outcomes in sickle cell disease (SCD) is limited. Moreover, 10-year survivorship of SCD implants is unknown. This study aimed to observe 10-year cumulative incidence and indications for revision TKA in patients who did and did not have SCD.

METHODS

Patients who underwent primary TKA were identified using a large national database. The SCD patients were matched by age, sex, and a comorbidity index to a control cohort in a 1:4 ratio. The 10-year cumulative incidence rates were determined using Kaplan-Meier survival analyses. Multivariable analyses were conducted using Cox proportional hazard modeling. Chi-squared analyses were conducted to compare indications for revision between cohorts. In total, 1,010 SCD patients were identified, 100,000 patients included in the unmatched control, and 4,020 patients included in the matched control.

RESULTS

Compared to the unmatched control cohort, SCD patients exhibited higher 10-year all-cause revision (HR: 1.86; P < .001) with higher proportions of revisions for periprosthetic joint infection (PJI) (P < .001), aseptic loosening (P < .001), and hematoma (P < .001). Compared to the matched control, SCD patients had higher 10-year all-cause revision (Hazard Ratio (HR): 1.39; P = .034) with a higher proportion of revisions for PJI (P = .044), aseptic loosening (P = .003), and hematoma (P = .019).

CONCLUSION

Independent of other comorbidities, SCD patients are more likely to undergo revisions for PJI, aseptic loosening, and hematoma compared to patients who do not have SCD. Due to the high-risk of these complications, perioperative and postoperative surgical optimization should be enforced in SCD patients.

Surgical approaches to periprosthetic femoral fractures for plate fixation or revision arthroplasty

Periprosthetic femoral fractures are increasing in incidence, and typically occur in frail elderly patients. They are similar to pathological fractures in many ways. The aims of treatment are the same, including 'getting it right first time' with a single operation, which allows immediate unrestricted weightbearing, with a low risk of complications, and one that avoids the creation of stress risers locally that may predispose to further peri-implant fracture. The surgical approach to these fractures, the associated soft-tissue handling, and exposure of the fracture are key elements in minimizing the high rate of complications. This annotation describes the approaches to the femur that can be used to facilitate the surgical management of peri- and interprosthetic fractures of the femur at all levels using either modern methods of fixation or revision arthroplasty.

The Challenge of Emerging Resistant Gram-Positive Pathogens in Hip and Knee Periprosthetic Joint Infections

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An increase in resistant bacterial pathogens has occurred over the last 4 decades.

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Careful patient selection and improving or correcting risk factors for periprosthetic joint infection (PJI) before elective surgical treatment are strongly recommended.

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Appropriate microbiological methods, including those used to detect and grow Cutibacterium acnes, are recommended.

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Antimicrobial agents used in the prevention or management of infection should be selected appropriately and the duration of therapy should be carefully considered in order to mitigate the risk of developing bacterial resistance.

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Molecular methods including rapid polymerase chain reaction (PCR) diagnostics, 16S sequencing, and/or shotgun and/or targeted whole-genome sequencing are recommended in culture-negative cases of PJI.

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Expert consultation with an infectious diseases specialist (if available) is recommended to assist with the appropriate antimicrobial management and monitoring of patients with PJI.

Do Elevated Serum C-Reactive-Protein Levels Excuse Delayed Surgery for Femoral Neck Fractures?

In elderly patients with femoral neck fractures, preoperative serum C-reactive protein (CRP) values might be elevated due to active infections. Although there are limited data on CRP as a predictor of periprosthetic joint infection (PJI), out of concern, this could lead to delayed surgery. Therefore, we aim to investigate whether elevated serum-CRP levels justify delayed surgery for femoral neck fractures. A retrospective analysis was performed of the records of patients undergoing arthroplasty who were found to have an elevated CRP level of 5 mg/dL or more between January 2011 to December 2020. The patients were stratified to three groups, according to initial serum CRP levels at a cut off of 5 mg/dL and the time between admission and surgery (<48 vs. ≥48 h after admission). This study revealed that the patients with elevated serum CRP levels and delayed surgery showed a worse survival rate and significantly more postoperative complications than the patients on whom surgery was performed immediately. There were no significant differences in terms of PJI and prolonged wound healing in the inter-group comparison. Therefore, delays to surgery on the basis of elevated CRP values offer no benefits to patients with femoral neck fractures.

Total Knee Arthroplasty in Patients with Spinal Cord Injury: Impact on Medical Complications, Hospital Costs and Length of Stay

INTRODUCTION

Patients with spinal cord injury (SCI) with degenerative joint disease of the knee may require total knee arthroplasty (TKA). This study examines the demographic and immediate postoperative outcomes of patients with SCI who undergo TKA.

METHODS

Admissions data for TKA and SCI were analyzed from the National Inpatient Sample database using International Classification of Diseases, 10th Revision, Clinical Modification diagnosis codes. An extensive array of preoperative and postoperative variables was compared among SCI TKA patients and non-SCI TKA patients. An unmatched and matched analysis using a 1:1 propensity match algorithm was conducted to compare the two groups.

RESULTS

Patients with SCI tend to be younger and have a 7.518 times greater risk of acute renal failure, 2.3 times greater risk of blood loss, and higher risk of local complications, including periprosthetic fracture and prosthetic infection. The average length of stay in the SCI cohort was 2.12 times greater, with a 1.58 times higher mean total incurred charge than the non-SCI group.

CONCLUSION

SCI is associated with an increased risk of acute renal failure, blood loss anemia, periprosthetic fractures and infections, a longer length of stay, and greater incurred charges in TKA patients.

STUDY DESIGN

Retrospective study.

Intraosseous Regional Administration of Antibiotic Prophylaxis for Total Knee Arthroplasty: A Systematic Review

BACKGROUND

Intraosseous regional administration (IORA) of antibiotics after tourniquet inflation has recently been introduced as a technique to deliver antibiotics directly to the surgical site among patients undergoing total knee arthroplasty (TKA).

METHODS

PubMed and Embase were queried for studies reporting on IORA for perioperative prophylaxis during TKA. Primary outcome measures were local tissue antibiotic concentrations and rates of prosthetic joint infection (PJI). Eight studies were included for analysis. Four studies (all randomized controlled trials) compared local tissue concentrations between patients receiving IORA and intravenous (IV) antibiotics. Six studies assessed the rate of PJI among patients receiving IORA versus IV antibiotics.

RESULTS

All studies found a statistically significant increase in antibiotic concentration in femoral bone and fat samples in patients who were treated with IORA (44.04 μg/g [fat] and 49.3 μg/g [bone] following 500 mg of intraosseous vancomycin) versus IV (3.5 μg/g [fat] and 5.2 μg/g [bone] following 1 g IV of vancomycin). The two studies powered to determine differences in PJI rates found a statistically significant decrease in the rate of PJI among patients receiving IORA versus IV antibiotics. The incidence of PJI in patients treated with IORA and IV antibiotics across all studies was 0.3 and 1.1%, respectively.

CONCLUSION

Perioperative IORA of antibiotics in TKA provides local tissue concentrations of antibiotics that are on average 10 times higher than IV administration alone. Although more adequately powered investigations are necessary to determine the effectiveness of IORA in reducing PJI rates, adoption of IORA should be considered in high-risk patients where elevated tissue antibiotic concentrations would be of a maximum benefit.

Enhanced Recovery after Total Joint Arthroplasty (TJA): A Contemporary Systematic Review of Clinical Outcomes and Usage of Key Elements

BACKGROUND

Enhanced recovery after surgery (ERAS) is a pathway designed to improve the care of surgical patients and achieve early recovery. The clinical outcomes and usage of key elements of ERAS pathways in total joint arthroplasty (TJA) need further reanalysis. This article aims to provide an overview of the latest clinical outcomes and current usage of key elements of ERAS pathways in TJA.

METHODS

We undertook a systematic review of the PubMed, OVID, and EMBASE databases in February 2022. Studies investigating the clinical outcomes and usage of key elements of ERAS in TJA were included. The components of successful ERAS programs and their usage were further determined and discussed.

RESULTS

Twenty-four studies involving 216,708 patients assessed ERAS pathways for TJA. A total of 95.8% (23/24) of studies reported a reduced length of stay (LOS), followed by reduce overall opioid consumption or pain (87.5% [7/8]), save costs (85.7% [6/7]), improvements in patient-reported outcomes or functional recovery (60% [6/10]), and reduced incidence of complications (50% [5/10]). In addition, preoperative patient education (79.2% [19/24]), anesthetic protocol (54.2% [13/24]), use of local anesthetics for infiltration analgesia or nerve blocks (79.2% [19/24]), perioperative oral analgesia (66.7% [16/24]), perioperative surgical factors including reduced use of tourniquets and drains (41.7% [10/24]), use of tranexamic acid (41.7% [10/24]) and early mobilization (100% [24/24]) were contemporary comparatively "active" components of ERAS.

CONCLUSIONS

ERAS for TJA has favorable clinical outcomes in terms of reducing LOS and overall pain, saving costs, accelerating functional recovery, and reducing complications, although the evidence is still low in quality. In the current clinical scenario, only some "active" components of the ERAS program are widely used.

Dose optimization in surgical prophylaxis: sub-inhibitory dosing of vancomycin increases rates of biofilm formation and the rates of surgical site infection

Antibiotic stewardship is viewed as having great public health benefit with limited direct benefit to the patient at the time of administration. The objective of our study was to determine if inappropriate administration of antibiotics could create conditions that would increase the rates of surgical infection. We hypothesized that sub-MIC levels of vancomycin would increase Staphylococcus aureus growth, biofilm formation, and rates of infection. S. aureus MRSA and MSSA strains were used for all experiments. Bacteria were grown planktonically and monitored using spectrophotometry. Quantitative agar culture was used to measure planktonic and biofilm bacterial burden. A mouse abscess model was used to confirm phenotypes in vivo. In the planktonic growth assay, increases in bacterial burden at ¼ MIC vancomycin were observed in USA300 JE2 by 72 h. Similar findings were observed with ½ MIC in Newman and SH1000. For biofilm formation, USA300 JE2 at ¼ and ½ MIC vancomycin increased biofilm formation by approximately 1.3- and 2.3-fold respectively at 72 h as compared to untreated controls. Similar findings were observed with Newman and SH1000 with a 2.4-fold increase in biofilm formation at ½ MIC vancomycin. In a mouse abscess model, there was a 1.2-fold increase with sub-MIC vancomycin at 3 days post infection. Our study showed that Sub-optimal vancomycin dosing promoted S. aureus planktonic growth and biofilm formation, phenotypic measures of bacterial virulence. This phenotype induced by sub-MIC levels of vancomycin was also observed to increase rates of infection and pathogenesis in our mouse model. Risks of exposure to sub-MIC concentrations with vancomycin in surgical procedures are greater as there is decreased bioavailability in tissue in comparison to other antibiotics. This highlights the importance of proper antibiotic selection, stewardship, and dosing for both surgical prophylaxis and treatment of infection.

Prevention Techniques Have Had Minimal Impact on the Population Rate of Prosthetic Joint Infection for Primary Total Hip and Knee Arthroplasty: A National Database Study

BACKGROUND

Several studies over the years have offered modalities that may greatly decrease the rate of periprosthetic joint infection when implemented. As a result, one would expect a drastic decrease in infection rate among the implementing population with its widespread use. The purpose of this study was to assess whether there exists a decrease in infection rate over time, after accounting for available confounding variables, within a large national database.

METHODS

A large national database from 2005 to 2019 was queried for primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). In total, 221,416 THAs and 354,049 TKAs were performed over the study period. Differences in 30-day infection rate were assessed with time and available preoperative risk factors using multinominal logistic regressions.

RESULTS

Rate of infection overall trended downward for both THA and TKA. After accounting for confounding variables, odds of THA infection marginally decreased over time (odds ratio 0.968 [0.952-0.985], P < .0001), while the odds of a TKA infection marginally increased with time (odds ratio 1.037 [1.020-1.054], P < .0001).

CONCLUSION

Individual peer-reviewed publications have presented infection control modalities demonstrating dramatic decreases in infection rate while analysis at a population level shows almost no changes in infection rate over a 15-year time period. This study supports continued investigation for influential modalities in preventing periprosthetic joint infection and care in patient selection for primary hip and knee arthroplasty.

Incidence, Risk Factors, and Subsequent Complications of Postoperative Hematomas Requiring Reoperation After Primary Total Hip Arthroplasty

Background

Studies analyzing the incidence and clinical implications of postoperative hematomas after total hip arthroplasty (THA) remain limited. The purpose of the present study was to use the National Surgical Quality Improvement Program (NSQIP) dataset to determine rates, risk factors, and subsequent complications of postoperative hematomas requiring reoperation after primary THA.

Methods

Study population included patients who underwent primary THA (CPT code: 27130) from 2012-2016 recorded in NSQIP. Patients who developed a hematoma requiring reoperation in the 30-day postoperative period were identified. Multivariate regressions were created to identify patient characteristics, operative variables, and subsequent complications that were associated with a postoperative hematoma requiring reoperation.

Results

Among the 149,026 patients who underwent primary THA, 180 (0.12%) developed a postoperative hematoma requiring reoperation. Risk factors included body mass index (BMI) ≥ 35 (relative risk [RR]: 1.83, P = .011), American Society of Anesthesiologists (ASA) class ≥3 (RR: 2.11, P < .001), and history of bleeding disorder (RR: 2.71, P < .001). Associated intraoperative characteristics were an operative time ≥100 minutes (RR: 2.03, P < .001) and use of general anesthesia (RR: 1.41, P = .028). Patients developing a hematoma requiring reoperation were at higher risk of subsequent deep wound infection (RR: 21.57, P < .001), sepsis (RR: 4.3, P = .012), and pneumonia (RR: 3.69, P = .023).

Conclusions

Surgical evacuation for a postoperative hematoma was performed in about 1 in 833 cases of primary THA. Several nonmodifiable and modifiable risk factors were identified. Given the 21.6 times increased risk of subsequent deep wound infection, select, at-risk patients may benefit from closer monitoring for signs of infection.

Extended Oral Antibiotic Prophylaxis After Aseptic Total Hip or Knee Arthroplasty Revisions: A Preliminary Report

BACKGROUND

It is unknown whether extended oral antibiotic (EOA) prophylaxis reduces periprosthetic joint infection (PJI) rates after aseptic revision total hip (THA) and knee arthroplasty (TKA). The literature is scarce. Therefore, we sought to ascertain whether EOA prophylaxis decreases PJI rates after aseptic first-time revision THA and TKA when compared to standard prophylaxis.

METHODS

This is a retrospective review of 328 consecutive revisions (3 surgeons, single institution, from September 27, 2017 to December 31, 2019). Preoperative 2013 Musculoskeletal Infection Society (MSIS) criteria, radiographs, and medications were reviewed. Inclusion criteria included aseptic first-time revision THA and TKA. Exclusion criteria were positive intraoperative cultures and/or histology, PJI (2013 MSIS criteria), hemiarthroplasty/partial arthroplasty revision, revision using foreign material (ie, mesh), metastatic bone disease, and intravenous antibiotics >24 hours after surgery. A total of 178 revisions were included, and 2 groups were set apart based on antibiotic prophylactic regime. The following were the groups: (1) EOA prophylaxis (>24 hours, n = 93) and (2) standard prophylaxis (≤24 hours, n = 85). Demographics, joint types, lengths of stay, skin-to-skin operative times, revision types, transfusions, discharge dispositions, and PJIs (per 2013 MSIS criteria) after the first-time revision were compared between groups. There were no significant differences in demographics. However, skin-to-skin operative time was significantly higher in the EOA group (123 minutes versus 98 minutes, P = .01). Mean follow-up was 849 days (range, 15-1,671). Statistical significance was set at a P value lower than .05.

RESULTS

Postoperative PJI rates were not significantly different: 2.2% EOA prophylaxis versus 3.5% standard prophylaxis (P = .671).

CONCLUSION

No significant difference was found between PJI rates between both prophylactic regimens. A large multicenter study with a larger sample size is needed to support EOA after aseptic revisions.

LEVEL OF EVIDENCE

Level III.

Extended Oral Antibiotic Prophylaxis After Aseptic Revision Total Hip Arthroplasty: Does It Decrease Infection Risk?

BACKGROUND

Extended oral antibiotic prophylaxis (EOA) has been shown to reduce infection after high-risk primary total hip arthroplasties (THAs) and reimplantations. However, data are limited regarding EOA after aseptic revision THAs. This study evaluated the impact of EOA on infection-related outcomes after aseptic revision THAs.

METHODS

We retrospectively identified 1,107 aseptic revision THAs performed between 2014 and 2019. Patients who received EOA >24 hours perioperatively (n = 370) were compared to those who did not (n = 737) using an inverse probability of treatment weighting model. Their mean age was 65 years (range, 19-98 years), mean body mass index was 30 kg/m² (range, 16-72), and 54% were women. Outcomes included cumulative probabilities of any infection, periprosthetic joint infection (PJI), and re-revision or reoperation for infection. Mean follow-up was 4 years (range, 2-8 years).

RESULTS

The cumulative probability of any infection after aseptic revision THA was 2.3% at 90 days, 2.7% at 1 year, and 3.5% at 5 years. The cumulative probability of PJI was 1.7% at 90 days, 2.1% at 1 year, and 2.8% at 5 years. There was a trend toward an increased risk of any infection (hazards ratio [HR] = 2.6; P = .058), PJI (HR = 2.6; P = .085), and re-revision (HR = 6.5; P = .077) or reoperation (HR = 2.3; P = .095) for infection in patients who did not have EOA at the final clinical follow-up.

CONCLUSIONS

EOA after aseptic revision THA was not associated with a statistically significant decreased risk of any infection, PJI, or re-revision or reoperation for infection at all time points.

LEVEL OF EVIDENCE

Level III.

"Recommendations for periprosthetic joint infections (PJI) prevention: the European Knee Associates (EKA)-International Committee American Association of Hip and Knee Surgeons (AAHKS)-Arthroplasty Society in Asia (ASIA) survey of members"

PURPOSE

Periprosthetic joint infections (PJIs) represent a devastating consequence of total joint arthroplasty. The European Knee Associates (EKA), the American Association of Hip and Knee Surgeons (AAHKS) International Committee, and the Arthroplasty Society in Asia (ASIA) board members were interested in quantifying differences in arthroplasty surgeons' use of various PJI prevention measures to provide clinical recommendations to reduce PJI incidence.

METHODS

A prospective Microsoft Forms online survey was distributed among EKA, AAHKS International Committee, and ASIA members and their affiliated arthroplasty surgeons. The survey consisted of 20 single and multiple response questions focused on PJI prevention strategies at three perioperative periods: preoperatively, intraoperatively, and postoperatively.

RESULTS

Three hundred and ninety-four arthroplasty surgeons from 6 different continents completed the survey. Preoperative: (A) PJI Risk Stratification: 40.6% routinely set thresholds (e.g., BMI, HgbA1C) to be met to qualify for surgery, 36.5% only review past medical history; 9.1% use machine learning to personalize PJI risk; (B) BMI limit: 36% no limit; 15.4% BMI < 35; 30.9% BMI < 40; 17.2% BMI < 45; (C) Nutritional status: 55.3% do not screen; among those who screen their patients (44.7%), albumin is the single most used marker (86.3%); (D) Hyperglycemia/Diabetes: 83.3% check this comorbidity; 88.1% use HgbA1C as single best screening test; (E) MRSA nasal colonization: 63.7% do not test; 28.9% test all patients; 7.4% test selectively. Intraoperative: (A) Antibiotic prophylaxis in high-risk patients: 43.4% use single antibiotic for 24 h; 21.3% use double antibiotic for 24 h; 14.2% use single/double antibiotic for 7 days postoperatively; (B) Skin-cleansing: 68.7% at home (45.6% chlorhexidine sponge; 11.9% clippers); (C) Intraoperative skin disinfection: 46.9% single chlorhexidine; 25% double chlorhexidine-povidone-iodine;15.4% single povidone-iodine; (D) Tranexamic acid (TXA) to reduce bleeding/SSI: 96% yes (51% double IV dose, 35.2% single IV dose, 23.6% intra-articular injection); (E) Surgical suction drain: 52% do not use drains; 19.7% use a drain < 24 h; (F) Intra-articular lavage: 64.9% use only saline; 28.1% use dilute povidone-iodine; (G) Antibiotic local delivery to prevent PJI: 82.4% use antibiotic-added cement. Postoperative: (A) Routine monitoring of PJI serologic markers: 42% only in symptomatic patients; 34.2% do not; 20.8% in all patients; (B) Serologic markers to rule in/out PJI: 95.9% CRP; 71% SEDRATE; 60.6% WBC; (C) Synovial fluid test to rule in/out PJI: 79.6% culture/sensitivity; 69.5% WBC count; 31.4% CRP.

CONCLUSIONS

This survey demonstrated that notable differences still exist in the application of PJI preventive measures across different geographic areas: Optimizing the patient preoperatively and applying multimodal intraoperative strategies represent newer, clinically relevant steps in the effort to reduce the burden of PJI. More uniform guidelines still need to be produced from international scientific societies in order facilitate a more comprehensive approach to this devastating complication.

LEVEL OF EVIDENCE

IV.

Individualized surgical antibiotic prophylaxis – why, when, and how?

"Surgical site infections (SSI) greatly concern clinicians, as they are associated with significant morbidity and mortality, prolonged hospitalization, and costs. Antibiotic prophylaxis plays a pivotal role among the procedures that are usually employed for the prevention of surgical-related infections. This narrative review aims to cover some of the particular situations when the clinician might consider individualizing antibiotic prophylaxis for a patient. With the rising incidence of multi-drug resistant bacteria carriage among not only hospitalized or institutionalized patients but also patients from the community, there might be a tendency to use extended-spectrum antibiotics for longer periods for surgical infection prevention. However, the inappropriate use of antibiotics increases the selection pressure, thus favoring the spreading of resistant bacteria. Moreover, specific patient characteristics or pathologies might need to be considered to customize the type, dose, or length of administration of an antibiotic as surgical prophylaxis. Using prosthetic material or prolonged surgeries with large fluid shifts are other situations when individualized antibiotic prophylaxis might be thought of. Keeping in mind that it is of utmost importance that everyone adheres to the current guidelines for surgical antibiotic prophylaxis, customization of local protocols according to well-thought-out strategies might prove beneficial in SSI prevention."

Post-operative prophylactic antibiotics in aseptic revision hip and knee arthroplasty: a propensity score matching analysis

The use of extended antibiotic (EA) prophylaxis (> 24 h) remains controversial in aseptic revision arthroplasty. We sought to determine whether EA prophylaxis reduces the risk of periprosthetic joint infection (PJI) in aseptic revision hip and knee arthroplasty. A total of 2800 patients undergoing aseptic revision hip and knee arthroplasty at five institutional databases from 2008 to 2017 were evaluated. One to two nearest-neighbor propensity score matching analysis was conducted between patients who did and did not receive extended antibiotic prophylaxis. The matching elements included age, sex, body mass index, Charlson comorbidity index, hospital distribution, year of surgery, joint (hip or knee), surgical time, CRP, preoperative hemoglobin, albumin, and length of stay. The primary outcome was the development of PJI, which was assessed at 30 days, 90 days, and 1 year following revision and analyzed separately. A total of 2467 (88%) patients received EA prophylaxis, and 333 (12%) patients received standard antibiotic (SA) prophylaxis (≤ 24 h). In the propensity-matched analysis, there was no difference between patients who received EA prophylaxis and those who did not in terms of 30-day PJI (0.3% vs. 0.3%, p = 1.00), 90-day PJI (1.7% vs. 2.1%, p = 0.62) and 1- year PJI (3.8% vs. 6.0%, p = 0.109). For revision hip, the incidence of PJI was 0.2% vs 0% at 30 days (p = 0.482), 1.6% vs 1.4% at 90 days (p = 0.837), and 3.4% vs 5.1% at 1 year (p = 0.305) in the EA and SA group. For revision knee, the incidence of PJI was 0.4% vs 0.9% at 30 days (p = 0.63), 1.8% vs 3.4% at 90 days (p = 0.331), and 4.4% vs 7.8% at 1 year (p = 0.203) in the EA and SA group. A post hoc power analysis revealed an adequate sample size with a beta value of 83%. In addition, the risks of Clostridium difficile and resistant organism infection were not increased. This multi-institutional study demonstrated no difference in the rate of PJIs between patients who received extended antibiotic prophylaxis and those who did not in aseptic revision arthroplasty. The risk of C. difficile and resistant organism infection was not increased with prolonged antibiotic use.

Rates of Antimicrobial Resistance With Extended Oral Antibiotic Prophylaxis After Total Joint Arthroplasty

Background

There is increased interest and utilization of extended oral antibiotic prophylaxis (EOAP) following primary and revision total hip arthroplasties (THAs) and total knee arthroplasties (TKAs). The purpose of this study was to look for potential associations between EOAP and differential rates of antimicrobial resistance or epidemiology of organisms causing periprosthetic joint infection (PJI) following primary and aseptic revision THAs/TKAs.

Methods

Patients who developed PJI following a primary or aseptic revision TKA/THA at a single institution from 2009 to 2020 were retrospectively identified. Patients who received at least 7 days of EOAP following the surgery were noted. Rates of antimicrobial resistance were compared between standard antibiotic prophylaxis and EOAP cohorts using the Fisher's exact test.

Results

One hundred twenty-eight cultures were obtained from 119 patients with PJI. Fourty-four cases (37%) developed PJI after EOAP. Staphylococcus aureus was the most frequently isolated organism (30% of all cultures; 78% were methicillin-sensitive). Rates of antimicrobial resistance were similar between standard antibiotic prophylaxis and EOAP cohorts in all but 2 instances: Increased resistance to erythromycin and trimethoprim-sulfamethoxazole was observed in coagulase-negative Staphylococci isolates in the EOAP cohort (89% vs 21%, P < .01; 44% vs 0%, P = .02). An increased frequency of gram-negative organisms was observed in the EOAP group (22% vs 8%, P = .03).

Conclusions

Rates of antimicrobial resistance were not significantly different between EOAP and standard antibiotic prophylaxis cohorts except in coagulase-negative Staphylococci. The increased frequency of gram-negative infections was present in the EOAP cohort. Larger, multicenter studies are needed to better understand the impact of EOAP on antimicrobial resistance and PJI epidemiology.

Level of Evidence

Level III; retrospective cohort study.

Cefadroxil-Induced Clostridium difficile Infection Following Total Knee Arthroplasty

Perioperative infection prophylaxis is a fundamental element of total knee arthroplasty (TKA). There has been a recent trend toward the use of extended postoperative oral antibiotics in high-risk patients. We describe a case report of a patient who underwent a primary TKA and subsequently developed Clostridium difficile colitis after an extended course of postoperative prophylactic oral cefadroxil. Following the C. difficile infection, the patient eventually developed bacteremia and a multidrug-resistant Escherichia coli prosthetic joint infection which required multiple debridements. Extended use of postoperative prophylactic oral cefadroxil may increase the risk of C. difficile-associated diarrhea. Additionally, our case suggests that C. difficile infection may subsequently increase the risk of bacteremia which could lead to prosthetic joint infection. More evidence is required to further define this risk.

Recrudescent infection after deep brain stimulator reimplantation

OBJECTIVE

The efficacy of deep brain stimulation (DBS) in treating the symptoms of movement disorders can be life changing for patients. Thus, the 5%-15% incidence of stimulator-related infection requiring removal of the device can be particularly disheartening. Although DBS system reimplantation is generally successful, this is not always the case. The literature is replete with publications describing the incidence of infection and the associated features. However, the literature is sparse in terms of information on the incidence of recurrent or recrudescent infection after system reimplantation. The goal of this paper was to evaluate factors leading to unsuccessful reimplantation of a DBS system following initial infection.

METHODS

Data were reviewed for all DBS procedures performed by one surgeon (K.L.H.) over 19 years including the infectious agent, location of infection, treatment regimen, and subsequent reimplantation of a DBS system and long-term outcome.

RESULTS

In this series of 558 patients who had undergone DBS surgery, 37 (6.6%) subsequently developed an infection. Infections with methicillin-sensitive Staphylococcus aureus, Enterobacter species, or coagulase-negative staphylococci were predominant. Four patients had cerebritis, one had meningitis, and the rest had soft tissue infections of the pocket or scalp. All had their entire DBS system explanted, followed by 4-6 weeks of intravenous antibiotics and surveillance for recrudescence for an additional period of at least 30 days. Twenty-five patients subsequently underwent DBS system reimplantation, and the procedure was successful in 22. Three of the 4 patients with cerebritis developed a subsequent wound infection after system reimplantation. None of the other 22 patients developed a recurrence. The odds ratio for developing a recurrent infection after cerebritis was 28.5 (95% CI 1.931-420.5, p = 0.007).

CONCLUSIONS

This study, the largest series of DBS system reimplantations following infection, demonstrated that most patients can have successful reimplantations without recurrent infection. However, patients who have had DBS-related cerebritis have a nearly 30-fold increased risk of developing reinfection after reimplantation. Alternative strategies for these patients are discussed.

The Cost-Effectiveness of Extended Oral Antibiotic Prophylaxis for Infection Prevention After Total Joint Arthroplasty in High-Risk Patients

BACKGROUND

Extended oral antibiotic prophylaxis may decrease rates of prosthetic joint infection (PJI) after total joint arthroplasty (TJA) in patients at high risk for infection. However, the cost-effectiveness of this practice is not clear. In this study, we used a break-even economic model to determine the cost-effectiveness of routine extended oral antibiotic prophylaxis for PJI prevention in high-risk TJA patients.

METHODS

Baseline PJI rates in high-risk patients, the cost of revision arthroplasty for PJI, and the costs of extended oral antibiotic prophylaxis regimens were obtained from the literature and institutional purchasing records. These variables were incorporated in a break-even economic model to calculate the absolute risk reduction (ARR) in infection rate necessary for extended oral antibiotic prophylaxis to be cost-effective. ARR was used to determine the number needed to treat (NNT).

RESULTS

Extended oral antibiotic prophylaxis with Cefadroxil in patients at high risk for PJI was cost-effective at an ARR in baseline infection rate of 0.187% (NNT = 535) and 0.151% (NNT = 662) for TKA and THA, respectively. Cost-effectiveness was preserved with varying costs of antibiotic regimens, PJI treatment costs, and infection rates.

CONCLUSION

The use of extended oral antibiotic prophylaxis may reduce PJI rates in patients at high risk for infection following TJA and appears to be cost-effective. However, the current evidence supporting this practice is limited in quality. The use of extended oral antibiotic prophylaxis should be weighed against the possible development of future antimicrobial resistance, which may change the value proposition.

Patients at a high risk of PJI: Can we reduce the incidence of infection using dual antibiotic-loaded bone cement?

Prosthetic joint infection (PJI) is one of the most devastating complications of orthopedic surgery. However, not all patients are equally at the risk of severe infection. The incidences of PJI vary with the host and surgery-related risk factors. It is now generally accepted that some important medical comorbidities may predispose the patients to a high risk of PJI. Time-consuming and invasive surgical procedures, such as revision arthroplasties, are also associated with a high incidence of PJI, presumably due to the increased risk of surgical site contamination. Effective infection-preventing strategies should begin with identifying and optimizing the patients at a high risk of infection prior to surgery. Optimizing the operating room environment and antibiotic prophylaxis are also essential strategies that help minimize the overall incidence of infection in orthopedic surgery. The ideal antibiotic prophylaxis is still under debate, and discussions have emerged about whether variations or adjustments to the standard protocol are justified in patients at a high risk of infection. This also includes evaluating the possible benefits and risks of using high-dose dual antibiotic-loaded bone cement instead of low-dose single antibiotic-loaded bone cement in arthroplasty. This review summarizes the evidence showing that the combination of two local antibiotics in bone cement exerts a strong and longer-lasting antimicrobial effect against PJI-associated pathogens. This conclusion is consistent with the preliminary clinical studies showing a low incidence of PJI in high-risk patients undergoing cemented hemiarthroplasty, cemented revision, and primary arthroplasty if dual ALBC is used. These results may encourage clinicians to consolidate this hypothesis in a wider clinical range.

Dual Antibiotic Prophylaxis in Primary Total Knee Arthroplasty-No Benefit for Extremely Obese Patients

We performed this study to assess the effectiveness of multimodal total knee arthroplasty prosthetic joint infection (TKA-PJI) prophylaxis including "on-time" dual-antibiotic prophylaxis, and the influence of body mass index (BMI) on prophylaxis effectiveness. After obtaining Institutional Review Board approval, we assessed 1,802 primary TKAs (1,496 patients) who received cefazolin alone or cefazolin combined with vancomycin for TKA-PJI prophylaxis. A detailed chart review was performed to determine patient demographic features (age, gender, BMI, American Society of Anesthesiologists Score), antibiotic selection, vancomycin administration timing, and 1-year PJI rates. Statistical assessment was accomplished using a two-sided Student's t-test or Fisher's exact test. Patients who received dual-antibiotic prophylaxis with "on time" vancomycin infusion (Group CVt) had significantly lower infection rates than other TKA patients (0.8 vs. 2.7%, p < 0.01). "On Time" vancomycin administration was associated with a lower TKA-PJI rate for patients with a BMI < 45 kg/m² (0.5 vs. 2.6%, p < 0.01) with no infections in 120 TKA patients with a BMI between 40 and 44.9 kg/m² (p < 0.01). No difference was noted for patients with a BMI ≥ 45 kg/m² (3.3 vs. 2.6%, p = 0.71). There were no infections in 150 TKA patients with a normal BMI (18-25 kg/m²) in any PJI-prophylaxis treatment group. Adoption of a dual-antibiotic prophylaxis approach can successfully reduce TKA-PJI rates among overweight and moderately obese patients. The approach does not appear to influence outcomes for low risk patients with a normal BMI (18-25 kg/m²) or for higher risk patients with a BMI > 45 kg/m².