Regional Intraosseous Administration of Prophylactic Antibiotics is More Effective Than Systemic Administration in a Mouse Model of TKA

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 intraosseous regional administration of tranexamic acid in total knee arthroplasty on perioperative blood loss: a protocol for a randomised controlled trial

INTRODUCTION

Total knee arthroplasty (TKA) is a common surgical intervention to treat joint diseases. However, TKA is associated with significant blood loss. Tranexamic acid (TXA) has been used to reduce perioperative bleeding and postoperative blood transfusion. This study aims to explore the effectiveness and safety of intraosseous regional administration (IORA) of TXA in TKA and compare differences in perioperative blood loss between IORA of TXA, intravenous infusion of TXA, and combined IORA and intravenous infusion of TXA.

METHODS AND ANALYSIS

This randomised controlled trial will enrol 105 patients with osteoarthritis who meet the inclusion criteria for unilateral TKA. Patients were randomly divided into three groups using the random number table method. Group A received 1.0 g of TXA via IORA, group B received 1.0 g of TXA via intravenous infusion 15 min prior to the tourniquet release, and group C received both IORA of 1.0 g of TXA and intravenous infusion of 1.0 g of TXA. The primary outcome measure is perioperative total blood loss. Secondary outcomes include bleeding events, venous thromboembolism events, inflammation reactions, other complications and knee function assessments.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of Peking Union Medical College Hospital and registered in the Chinese Clinical Trial Registry. Informed consent will be obtained from all the patients before enrolment. The trial will be conducted in accordance with the principles of the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice guidelines. The results of this study will be disseminated through peer-reviewed publications, conference presentations and social media platforms. The findings will provide valuable insights into the use of IORA of TXA in TKA and may lead to the development of new strategies for perioperative blood management in joint replacement surgery.

TRIAL REGISTRATION NUMBER

The Ethics Committee of Peking Union Medical College Hospital (approval number: K2371); Chinese Clinical Trial Registry (trial registration number: ChiCTR2200066293).

Rat model of recalcitrant prosthetic joint infection using biofilm inocula

Prosthetic joint infection (PJI) is a rare but devastating complication of joint arthroplasty. Biofilm formation around the prosthesis confers tolerance to antibiotics so that treatment is challenging. Most animal models of PJI use planktonic bacteria to establish the infection which fails to reproduce the pathology of chronic infection. We aimed to establish a rat model of Staphylococcus aureus PJI in male Sprague-Dawley rats using biofilm inocula and demonstrate its tolerance to frontline antibiotics. Pilot studies indicated that infection could be introduced to the knee joint by a biofilm-coated pin but that handling the prosthetic without disturbing the biofilm was difficult. We, therefore, developed a pin with a slotted end and used a miniature-biofilm reactor to develop mature biofilm in this niche. These biofilm-laden pins consistently produced infection of the bone and joint space. Treatment with high dose cefazolin, 250 mg/kg, starting the day of surgery reduced or cleared pin-adherent bioburden within 7 days, however when escalation from 25 to 250 mg/kg cefazolin treatment was delayed for 48 h, rats were unable to clear the infection. To track infections, we used bioluminescent bacteria, however, the bioluminescent signal did not accurately track the degree of infection in the bone and joint space as the signal did not penetrate the bone. In conclusion, we demonstrate that using a custom prosthetic pin, we can generate biofilm in a specific niche using a novel bioreactor setup and initiate a rat PJI that rapidly develops tolerance to supra-clinical doses of cefazolin.

Intraosseous regional prophylaxis in total knee arthroplasty

Prophylactic antibiotics are important in reducing the risk of periprosthetic joint infection (PJI) following total knee arthroplasty. Their effectiveness depends on the choice of antibiotic and the optimum timing of their administration, to ensure adequate tissue concentrations. Cephalosporins are typically used, but an increasing number of resistant organisms are causing PJI, leading to the additional use of vancomycin. There are difficulties, however, with the systemic administration of vancomycin including its optimal timing, due to the need for prolonged administration, and potential adverse reactions. Intraosseous regional administration distal to a tourniquet is an alternative and attractive mode of delivery due to the ease of obtaining intraosseous access. Many authors have reported the effectiveness of intraosseous prophylaxis in achieving higher concentrations of antibiotic in the tissues compared with intravenous administration, providing equal or enhanced prophylaxis while minimizing adverse effects. This annotation describes the technique of intraosseous administration of antibiotics and summarizes the relevant clinical literature to date.

Higher cefazolin concentrations in synovial fluid with intraosseous regional prophylaxis in knee arthroplasty: a randomized controlled trial

BACKGROUND

Prophylactic antibiotics reduce the risk of periprosthetic joint infection. However, conventional systemic administration may not provide adequate tissue concentrations against more resistant organisms such as coagulase-negative staphylococci. Intraosseous regional administration is known to achieve significantly higher antibiotic tissue concentrations than systemic administration, but it is unclear how synovial fluid concentrations are affected. We aimed to compare synovial fluid cefazolin concentrations achieved by regional intraosseous versus systemic intravenous administration, and also to compare synovial fluid cefazolin concentrations with those in subcutaneous fat.

METHODS

A total of 60 patients undergoing primary knee arthroplasty were randomized into 2 groups: group IO received 2 g interosseous cefazolin in 100 mL saline through a tibial cannula after tourniquet inflation and before skin incision; group IV received 2 g cefazolin in 100 mL saline via the median basilic or median cephalic vein 30 min before tourniquet inflation. Subcutaneous fat and synovial fluid samples were collected immediately after skin incision, and cefazolin concentrations were measured by high-performance liquid chromatography.

RESULTS

The cefazolin concentration in synovial fluid was 391.3 ± 70.1 μg/ml in group IO and 17.6 ± 3.5 μg/ml in group IV. The cefazolin concentration in subcutaneous fat was 247.9 ± 64.9 μg/g in group IO and 11.4 ± 1.9 μg/g in group IV.

CONCLUSION

Intraosseous regional administration results in several times higher tissue concentrations than systemic administration, especially in the synovial fluid.

Principles of mechanical and chemical debridement with implant retention

BACKGROUND

Periprosthetic joint infection (PJI) is one of the most common causes of early revision for total hip and knee arthroplasty. Mechanical and chemical debridement typically referred to as debridement, antibiotics, and implant retention (DAIR) can be a successful technique to eradicate PJI in acute postoperative or acute hematogenous infections. This review will focus specifically on the indications, techniques, and outcomes of DAIR.

DISCUSSION

The success of mechanical and chemical debridement, or a DAIR operation, is reliant on a combination of appropriate patient selection and meticulous technique. There are many technical considerations to take into consideration. One of the most important factors in the success of the DAIR procedure is the adequacy of mechanical debridement. Techniques are surgeon-specific and perhaps contribute to the large variability in the literature on the success of DAIR. Factors that have been shown to be associated with success include the exchange of modular components, performing the procedure within seven days or less of symptom onset, and possibly adjunctive rifampin or fluoroquinolone therapy, though this remains controversial. Factors that have been associated with failure include rheumatoid arthritis, age greater than 80 years, male sex, chronic renal failure, liver cirrhosis, and chronic obstructive pulmonary disease.

CONCLUSIONS

DAIR is an effective treatment option for the management of an acute postoperative or hematogenous PJI in the appropriately selected patient with well-fixed implants.

Intraosseous Regional Administration of Prophylactic Antibiotics in Total Knee Arthroplasty

Prosthetic joint infection (PJI) after total knee arthroplasty is a devastating complication. With the development of antibiotic resistance, a safe and effective means of delivering antibiotic prophylaxis is needed. Intraosseous regional antibiotics (IORA) achieve higher local concentrations of antibiotics with fewer systemic side effects. Previous studies have proven the safety of IORA, whereas animal models have proven it to be more effective than intravenous antibiotics for preventing infection following surgery. Recently, large-scale retrospective studies have also demonstrated lower PJI rates following TKA when IORA is used when compared to routine intravenous prophylaxis. In this article, we propose an evidence-based method for the administration of intraosseous antibiotics in TKA, cover the up-to-date data supporting its use, and explore future directions for additional research.

Higher Tissue Concentrations of Vancomycin Achieved With Low-Dose Intraosseous Injection Versus Intravenous Despite Limited Tourniquet Duration in Primary Total Knee Arthroplasty: A Randomized Trial

BACKGROUND

Vancomycin use has been suggested in high risk patients undergoing total knee arthroplasty (TKA). Previous literature has shown that a lower dose (500 mg) of vancomycin given by intraosseous regional administration (IORA) achieves tissue concentrations 4-10 times higher than intravenous (IV) administration. There is increasing interest in performing TKA with limited tourniquet inflation time. The purpose of this study is to evaluate whether IORA of vancomycin can achieve effective tissue concentrations with limited tourniquet inflation time.

METHODS

Based on prior power calculations, 24 patients undergoing primary TKA were randomized into 2 groups. Group IV-Systemic received weight-based (15 mg/kg) vancomycin with the tourniquet inflated for cementation only. Group IORA received 500 mg vancomycin via IORA after tourniquet inflation which remained inflated for 10 minutes, then reinflated for cementation only. Vancomycin concentrations from tissue, serum, and drain fluid were compared between the 2 groups.

RESULTS

Median vancomycin concentrations in tissue were significantly higher (5-15 times) at all time points in the IORA group. Concentrations in fat at the time of wound closure, after the tourniquet had been deflated for most of the procedure, were 5.2 μg/g in Group IV-Systemic and 33.1 μg/g in Group IORA (P < .001). Median bone concentrations taken just prior to cementation were 7.9 μg/g in Group IV-Systemic and 21.8 μg/g in Group IORA (P = .006). There were no complications related to IORA.

CONCLUSION

For surgeons who wish to limit tourniquet time and when indicated to use vancomycin, low-dose vancomycin IORA achieves tissue concentrations 5-15 times higher than those achieved by IV administration.

LEVEL OF EVIDENCE

Level 1 therapeutic randomized trial.

Intraosseous Regional Prophylactic Antibiotics Decrease the Risk of Prosthetic Joint Infection in Primary TKA: A Multicenter Study

BACKGROUND

Recent studies have demonstrated that the administration of regional prophylactic antibiotics by intraosseous (IO) injection achieves tissue concentrations around the knee that are 10- to 15-fold higher than intravenous (IV) delivery of prophylactic antibiotics. It is currently unknown whether the use of regional prophylactic antibiotics for primary TKA would result in a lower risk of prosthetic joint infection (PJI).

QUESTIONS/PURPOSES

(1) Is IO injection of prophylactic antibiotics associated with a decreased risk of early (< 12 months) deep PJI compared with traditional IV prophylactic antibiotics? (2) What other patient factors are associated with an increased risk of early PJI after TKA, and do regional prophylactic antibiotics influence these risk factors? (3) Can IO antibiotics be administered to all patients, and what complications occurred from the delivery of IO prophylactic antibiotics?

METHODS

A retrospective comparative study of all primary TKAs (1909 TKAs) over a 5-year period (January 2013 to December 2017) was performed to determine the risk of early PJI. Three primary TKAs did not meet the study inclusion criteria and were excluded from the study, leaving a total of 1906 TKAs (725 IO, 1181 IV) for analysis at a minimum of 12 months after index procedure. Both cohorts exhibited similar ages, BMI, and American Society of Anesthesiologists (ASA) grades; however, a greater proportion of patients in the IO cohort were smokers (p = 0.01), while a greater proportion of patients were diabetic in the IV cohort (p = 0.006). The PJI risk between IO and IV delivery techniques was compared while adjusting for patient demographics and medical comorbidities. Complications related to IO delivery-inability to administer via IO technique, compartment syndrome, fat embolism, and red man syndrome with vancomycin use-were recorded.

RESULTS

The delivery of regional prophylactic antibiotics by the IO technique resulted in a lower PJI risk than IV prophylactic antibiotics (0.1% [1 of 725] compared with 1.4% [16 of 1181]; relative risk 0.10 [95% CI 0.01 to 0.77]; p = 0.03). BMI (β = -0.17; standard error = 0.08; p = 0.02), diabetes (β = -1.80; standard error = 0.75; p = 0.02), and renal failure (β = -2.37; standard error = 0.84; p = 0.01) were factors associated with of PJI, while smoking, sex, and ASA score were not contributing factors (p > 0.05). Although BMI, diabetes, and renal failure were identified as infection risk factors, the use of IO antibiotics in these patients did not result in a lower PJI risk compared with IV antibiotics (p > 0.05). IO antibiotics were able to be successfully administered to all patients in this cohort, and there were no complications related to the delivery of IO antibiotics.

CONCLUSION

Surgeons should consider administering regional prophylactic antibiotics in primary TKA to reduce the risk of early PJI. Future randomized prospective clinical trials are needed to validate the efficacy of regional prophylactic antibiotics in reducing the PJI risk in primary TKA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Incomplete Administration of Intravenous Vancomycin Prophylaxis is Common and Associated With Increased Infectious Complications After Primary Total Hip and Knee Arthroplasty

BACKGROUND

Vancomycin is often used as antimicrobial prophylaxis in patients undergoing total hip or knee arthroplasty. Vancomycin requires longer infusion times to avoid associated side effects. We hypothesized that vancomycin infusion is often started too late and that delayed infusion may predispose patients to increased rates of surgical site infections and prosthetic joint infections.

METHODS

We reviewed clinical data for all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients at our institution between 2013 and 2020 who received intravenous vancomycin as primary perioperative gram-positive antibiotic prophylaxis. We calculated duration of infusion before incision or tourniquet inflation, with a cutoff of 30 minutes defining adequate administration. Patients were divided into two groups: 1) appropriate administration and 2) incomplete administration. Surgical factors and quality outcomes were compared between groups.

RESULTS

We reviewed 1047 primary THA and TKA patients (524 THAs and 523 TKAs). The indication for intravenous vancomycin usage was allergy (61%), methicillin-resistant staphylococcus aureus colonization (17%), both allergy and colonization (14%), and other (8%). 50.4% of patients began infusion >30 minutes preoperatively (group A), and 49.6% began infusion <30 minutes preoperatively (group B). Group B had significantly higher rates of readmissions for infectious causes (3.6 vs 1.3%, P = .017). This included a statistically significant increase in confirmed prosthetic joint infections (2.2% vs 0.6%, P = .023). Regression analysis confirmed <30 minutes of vancomycin infusion as an independent risk factor for PJI when controlling for comorbidities (OR 5.22, P = .012).

CONCLUSION

Late infusion of vancomycin is common and associated with increased rates of infectious causes for readmission and PJI. Preoperative protocols should be created to ensure appropriate vancomycin administration when indicated.

Results of debridement, antibiotics, and implant retention for periprosthetic knee joint infection supplemented with the use of intraosseous antibiotics

AIMS

Debridement, antibiotics, and implant retention (DAIR) remains one option for the treatment of acute periprosthetic joint infection (PJI) despite imperfect success rates. Intraosseous (IO) administration of vancomycin results in significantly increased local bone and tissue concentrations compared to systemic antibiotics alone. The purpose of this study was to evaluate if the addition of a single dose of IO regional antibiotics to our protocol at the time of DAIR would improve outcomes.

METHODS

A retrospective case series of 35 PJI TKA patients, with a median age of 67 years (interquartile range (IQR) 61 to 75), who underwent DAIR combined with IO vancomycin (500 mg), was performed with minimum 12 months' follow-up. A total of 26 patients with primary implants were treated for acute perioperative or acute haematogenous infections. Additionally, nine patients were treated for chronic infections with components that were considered unresectable. Primary outcome was defined by no reoperations for infection, nor clinical signs or symptoms of PJI.

RESULTS

Mean follow-up for acute infection was 16.5 months (12.1 to 24.2) and 15.8 months (12 to 24.8) for chronic infections with unresectable components. Overall non-recurrence rates for acute infection was 92.3% (24/26) but only 44.4% (4/9) for chronic infections with unresectable components. The majority of patients remained on suppressive oral antibiotics. Musculoskeletal Infection Society (MSIS) host grade was a significant indicator of failure (p < 0.001).

CONCLUSION

The addition of IO vancomycin at the time of DAIR was shown to be safe with improved results compared to current literature using standard DAIR without IO antibiotic administration. Use of this technique in chronic infections should be applied with caution. While these results are encouraging, this technique requires longer follow-up before widespread adoption. Cite this article: Bone Joint J 2021;103-B(6 Supple A):185-190.

2021 Chitranjan S. Ranawat Award: Intraosseous vancomycin reduces periprosthetic joint infection in primary total knee arthroplasty at 90-day follow-up

AIMS

Infection complicating primary total knee arthroplasty (TKA) is a common reason for revision surgery, hospital readmission, patient morbidity, and mortality. Increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) is a particular concern. The use of vancomycin as prophylactic agent alone or in combination with cephalosporin has not demonstrated lower periprosthetic joint infection (PJI) rates, partly due to timing and dosing of intravenous (IV) vancomycin administration, which have proven important factors in effectiveness. This is a retrospective review of a consecutive series of primary TKAs examining incidence of PJI, adverse reactions, and complications using IV versus intraosseous (IO) vancomycin at 30-day, 90-day, and one-year follow-up.

METHODS

A retrospective review of 1,060 patients who underwent TKA between May 2016 to July 2020 was performed. There were 572 patients in the IV group and 488 in the IO group, with minimal 30 days of follow-up. Patients were followed up at regularly scheduled intervals (two, six, and 12 weeks). No differences between groups for age, sex, BMI, or baseline comorbidities existed. The IV group received an IV dose of 15 mg/kg vancomycin given over an hour preceding skin incision. The IO group received a 500 mg dose of vancomycin mixed in 150 ml of normal saline, injected into proximal tibia after tourniquet inflation, before skin incision. All patients received an additional dose of first generation cephalosporin. Evaluation included preoperative and postoperative serum creatinine values, tourniquet time, and adverse reactions attributable to vancomycin.

RESULTS

Incidence of PJI with minimum 90-day follow-up was 1.4% (eight knees) in the IV group and 0.22% (one knee) in IO group (p = 0.047). This preliminary report demonstrated an reduction in the incidence of infection in TKA using IO vancomycin combined with a first-generation cephalosporin. While the study suffers from limitations of a retrospective, multi-surgeon investigation, early findings are encouraging.

CONCLUSION

IO delivery of vancomycin after tourniquet inflation is a safe and effective alternative to IV administration, eliminating the logistical challenges of timely dosing. Cite this article: Bone Joint J 2021;103-B(6 Supple A):13-17.

Intraosseous Regional Administration of Antibiotic Prophylaxis in Total Knee Arthroplasty

Background

Periprosthetic joint infection (PJI) is a devastating complication following total knee arthroplasty (TKA), and perioperative antibiotics are commonly administered to try to mitigate the chance of infection. Intraosseous regional administration (IORA) of prophylactic antibiotics during TKA is a method of antibiotic delivery that has been shown to achieve markedly higher tissue concentrations at much lower doses. Other advantages include ease of administration, ability to time the antibiotic delivery with the surgical start time for maximal effectiveness, and less systemic side effects. The concept is similar to a Bier block, except that IORA involves the use of antibiotics instead of local anesthetic to perfuse the limb and is given via intraosseous rather than intravenous access.

Description

After standard patient preparation and draping, the tourniquet is inflated and an intraosseous needle is inserted into the proximal medial face of the tibia, just medial and slightly above the level of the tubercle. A large syringe containing the desired antibiotic (typically 500 mg vancomycin suspended in normal saline solution) is connected to the needle and the solution is administered over 1 to 2 minutes. The intraosseous needle can then be removed and the surgical procedure proceeds as it normally would per surgeon preference and technique.

Alternatives

Systemic administration of intravenous antibiotics, vancomycin powder, and antibiotic-impregnated cement are alternative options that can be utilized during TKA.

Rationale

IORA has several distinct advantages over other methods of antibiotic delivery, including the ability to (1) deliver antibiotic directly to the surgical bed and avoid systemic delivery, (2) precisely time and quickly administer antibiotics to achieve highest concentrations at the start of and throughout the surgical procedure, and (3) avoid several common and potentially serious side effects, especially those associated with antibiotics such as vancomycin.

Expected Outcomes

This technique for antibiotic delivery achieves markedly higher tissue concentrations compared with systemic administration, without prolonged preoperative infusion times. Intraosseous delivery optimizes timing and reduces the risk of systemic side effects while simultaneously providing equal or enhanced antibiotic prophylaxis in TKA. This delivery mechanism is especially useful in patients who are at high risk for infection and in the revision TKA setting. Further, there is little to no additional risk and the use of this method does not substantially prolong operative time.

Important Tips

The proximal aspect of the tibia is the optimal injection site because the cortex is thinner in this region, making needle insertion easier. Additionally, the metaphyseal bone allows faster flow rates for the infusion. We have found that insertions made slightly more proximally are easier and have faster flow rates. Of note, although the antibiotic is infused into the tibia, as seen in the attached technique video, intraosseous administration achieves rapid uptake into the vascular tree. Therefore, all tissues distal to the tourniquet, including the femur and patella, will receive this optimal dose as well.We prefer the use of a power driver (EZ-IO; Teleflex); however, manual needles (Cook Medical) can also be utilized. Longer needles are available if needed for obese patients.Flow rates are variable and the infusion typically takes 1 to 2 minutes to complete. If the flow rate is slow, twisting and withdrawing the needle slightly (2 to 4 mm) may increase the rate. This contrasts with the 1 to 2-hour intravenous infusion time required when vancomycin is administered systemically.In our experience, intraosseous injection is still successful in the case of a previous high tibial osteotomy, although the flow rate may be slower.In complex revision cases with compromised proximal tibial bone, the medial malleolus is an alternative site for intraosseous administration.Choice of antibiotic: as vancomycin is difficult to adequately administer intravenously, it is ideally suited for IORA. We have studied and utilized a 500-mg dose of vancomycin suspended in a solution of 140 mL of normal saline solution (prepared by our pharmacy). Of note, we have not found rapid infusion of intraosseous vancomycin to cause red-man syndrome as it would with rapid systemic infusion. This is because of the lower dose of 500 mg and the use of the tourniquet, which keeps the antibiotic in the local tissues about the knee without allowing systemic exposure. All patients, regardless of weight or the size of their limb, receive the dose of 500 mg of vancomycin.As cefazolin does not have the same difficulties with intravenous administration, we continue to use standard intravenous prophylaxis with an appropriate weight-based dose of cefazolin prior to incision.Indications for IORA of vancomycin include clinical scenarios in which vancomycin would be administered intravenously. These indications include revision TKA, obesity (body mass index >40 kg/m²), diabetes, beta-lactam allergy, known colonization with methicillin-resistant Staphylococcus aureus (MRSA), patients coming from institutions with a high prevalence of MRSA, previous ligamentous surgical procedure or osteotomies, and current or recent smokers. IORA can be utilized even in the primary TKA setting if the patient is considered high-risk as defined by the criteria above. We also use IORA during reimplantation following 2-stage exchange for PJI and in patients undergoing irrigation and debridement for acute PJI when the organism has been identified preoperatively.

Contemporary Strategies to Prevent Infection in Hip and Knee Arthroplasty

PURPOSE OF REVIEW

Prosthetic joint infection (PJI) remains a serious concern in lower limb arthroplasty. Despite the significant consequences of PJI, the assessment of the safety and efficacy of preventative measures is challenging due to a low event rate. Notwithstanding, enormous efforts have been made in this arena, and prevention strategies continue to evolve. This review provides an update on contemporary literature (published within the last 5 years) pertaining to infection prevention in primary hip and knee arthroplasty.

RECENT FINDINGS

Patient optimization has been highlighted as a critical preoperative factor in mitigating PJI risk. Recent evidence emphasizes the importance of preoperative glycaemic control, nutritional status, weight optimization and smoking cessation prior to hip and knee arthroplasty. Perioperatively, attention to detail in terms of surgical skin preparation agent and technique as well as prophylactic antibiotic agent, spectrum, dose and timing is important with statistically and clinically significant differences seen between differing strategies. Intraosseous regional antibiotic administration is an emerging technique with promising preclinical data. Dilute betadine lavage also shows promise. Data supporting bundled interventions continues to grow. A multimodal approach is required in PJI prevention, and attention to detail is important with each element. Patient optimization is critical, as is the execution of the planned perioperative infection prevention strategy.

Effectiveness of Prophylactic Intraosseous Antibiotic versus Intravenous Antibiotic in Knee Surgeries in Pigs: Experimental Study

Objective  To demonstrate that the intraosseous (IO) access is more effective compared with the intravenous (IV) access for prophylactic antibiotic administration in knee joint surgeries, using 36 pigs as live models.

Materials and Methods  Skin, subcutaneous tissue, cartilage, and bone samples were collected, analyzed and compared after the administration of IV or IO antibiotic in different groups.

Results  When comparing the IO and IV groups, the IO group showed a higher concentration of prophylactic antibiotic in the skin ( p  = 0.049), cartilage ( p  = 0.018), and bone ( p  = 0.002), in the analysis of the first 24 hours after 30 minutes of infusion.

Conclusion  Since complications regarding this practice are rare, the use of this pathway may be an alternative to reduce the risk of surgical site infection in orthopedic surgeries, leading to a decrease in morbidity and mortality and hospital expenses with readmission or prolonged hospitalization time. However, further research and further experimental studies in humans are required, as the effectiveness of the method in pigs has been proved.

Use of regional administration of prophylactic antibiotics in total knee arthroplasty

Prosthetic joint infection after total knee arthroplasty is an infrequent, yet serious complication. Antimicrobial prophylaxis plays an important role in reducing the rate of surgical site infections. To be effective as an antimicrobial prophylaxis, the serum, tissue and bone concentrations of the antibiotic must be greater than the target organism's minimum inhibitory concentration. As antibiotic resistance increases current intravenous prophylactic dosing has been shown to be subtherapeutic for some patients. Intravenous regional administration and intraosseous regional administration of prophylactic antibiotics are novel methods used to increase the antibiotic tissue concentrations, which may enhance the efficacy of prophylactic antibiotics in total knee arthroplasty. Currently, literature has shown both intravenous regional administration and intraosseous regional administration to be safe and effective techniques. However, there is no clinical evidence to show that it results in a reduction of prosthetic joint infection rates. This study summarizes the current knowledge base on the use of regional administration of prophylactic antibiotics in total knee arthroplasty.

The AAHKS Clinical Research Award: Intraosseous Regional Prophylaxis Provides Higher Tissue Concentrations in High BMI Patients in Total Knee Arthroplasty: A Randomized Trial

BACKGROUND

Obesity is an established risk factor for periprosthetic joint infections after total knee arthroplasty (TKA). In obese patients, a larger dose of prophylactic vancomycin based on actual body weight is required to reach therapeutic concentrations. It is unclear how tissue concentrations are affected when intraosseous regional administration (IORA) is used in this population. This study compared tissue concentrations of low-dose vancomycin via IORA vs actual body weight-adjusted systemic intravenous (IV) dose in primary TKA.

METHODS

Twenty-two patients with a body mass index (BMI) >35 undergoing TKA were randomized into 2 groups. The IV group received 15 mg/kg (maximum of 2 g) of systemic IV vancomycin and the IORA group received 500 mg vancomycin into the tibia. Subcutaneous fat and bone samples were taken at regular intervals. Tissue antibiotic concentrations were measured using liquid chromatography coupled with tandem mass spectrometry. A blood sample was taken 1 to 2 hours after tourniquet deflation to measure systemic concentration.

RESULTS

The mean BMI was 41.1 in the IORA group and 40.1 in the IV systemic group. The overall mean tissue concentration in subcutaneous fat was 39.3 μg/g in the IORA group and 4.4 μg/g in the IV systemic group (P < .01). Mean tissue concentrations in bones were 34.4 μg/g in the IORA group and 6.1 μg/g in the IV systemic group (P < .01).

CONCLUSION

Low-dose IORA was effective in the high-BMI population group, providing tissue concentrations of vancomycin 5-9 times higher than systemic administration. IORA optimizes timing of vancomycin administration and provides high tissue antibiotic concentrations during TKA in this high-risk patient group.

The John N. Insall Award: Higher Tissue Concentrations of Vancomycin Achieved With Intraosseous Regional Prophylaxis in Revision TKA: A Randomized Controlled Trial

BACKGROUND

In primary TKA, prophylaxis with low-dose vancomycin through intraosseous regional administration (IORA) achieves tissue concentrations six to 10 times higher than systemic administration and was shown to provide more effective prophylaxis in an animal model. However, in revision TKA, the presence of a tibial implant may compromise IORA injection, and tourniquet deflation during a prolonged procedure may lower tissue concentrations.

QUESTIONS/PURPOSES

(1) Does low-dose IORA reliably provide equal or higher tissue concentrations of vancomycin compared with systemic IV administration in revision TKA? (2) Are tissue concentrations of vancomycin after IORA maintained for the duration of the revision TKA despite a period of tourniquet deflation? (3) Is there any difference in early postoperative (< 6 weeks) complications between IORA and systemic IV administration in revision TKA?

METHODS

Twenty patients undergoing aseptic revision TKA were randomized to two groups. The IV group received 1 g systemic IV prophylactic vancomycin. The IORA group received 500 mg vancomycin as a bolus injection into a tibial intraosseous cannula below an inflated thigh tourniquet before skin incision. In all patients receiving IORA, intraosseous tibial injection was technically possible despite the presence of a tibial implant. Mean procedure length was 3.5 hours in both groups. Mean initial tourniquet inflation was 1.5 hours with a second inflation for a mean of 35 minutes during cementation. During the procedure, subcutaneous fat and bone samples were taken at regular intervals. Tissue vancomycin concentrations were measured using high-performance liquid chromatography.

RESULTS

Overall geometric mean tissue concentration of vancomycin in fat samples was 3.7 μg/g (95% confidence interval [CI], 2.6-5.2) in the IV group versus 49.3 μg/g in the IORA group (95% CI, 33.2-73.4; ratio between means 13.5; 95% CI, 8.2-22.0; p < 0.001); mean tissue concentrations in femoral bone were 6.4 μg/g (95% CI, 4.5-9.2) in the IV group versus 77.1 μg/g (95% CI, 42.4-140) in the IORA group (ratio between means 12.0; 95% CI, 6.2-23.2; p < 0.001). Vancomycin concentrations in the final subcutaneous fat sample taken before closure were 5.3 times higher in the IORA group versus the IV group (mean ± SD, 18.2 ± 11.6 μg/g IORA versus 3.6 ± 2.5 μg/g; p < 0.001). The intraarticular concentration of vancomycin on postoperative Day 1 drain samples was not different between the two groups with the numbers available (mean 4.6 μg/L in the IV group versus 6.6 μg/g in the IORA group; mean difference 2.0 μg/g; 95% CI, 6.2-23.2; p = 0.08).

CONCLUSIONS

IORA administration of vancomycin in patients undergoing revision TKA resulted in tissue concentrations of vancomycin five to 20 times higher than systemic IV administration despite the lower dose. High tissue concentrations were maintained throughout the procedure despite a period of tourniquet deflation. These preliminary results justify prospective cohort studies, which might focus on broader safety endpoints in more diverse patient populations. We believe that these studies should evaluate patients undergoing revision TKA in particular, because the risk of infection is greater than in patients undergoing primary TKA.

LEVEL OF EVIDENCE

Level I, therapeutic study.

Role of Systemic and Local Antibiotics in the Treatment of Open Fractures

The orthopedic community has learned much about the treatment of open fractures from the tremendous work of Ramon Gustilo, Michael Patzakis, and others; however, open fractures continue to be very difficult challenges. Type III open fractures continue to be associated with high infection rates. Some combination of systemic and local antibiotics may be most appropriate in these high-grade open fractures. Further research is still necessary in determining optimal systemic antibiotic regimens as well as the role of local antibiotics. Any new discoveries related to novel systemic antibiotics or local antibiotic carriers will need to be evaluated related to cost.

Theoretical approach to local infusion of antibiotics for infected pancreatic necrosis

BACKGROUND/OBJECTIVES

Infected pancreatic necrosis is a major complications of acute pancreatitis. If drainage is required, local administration of antibiotics through transmural nasocystic or percutaneous catheter may allow increasing local antibiotic concentrations. Drug diffusion becomes the main factor influencing local drug tissue penetration. The present study aims at providing the rationale for the design of new research protocols evaluating the efficacy of local antibiotics for infected pancreatic necrosis.

METHODS

A review of microbiological data was performed for the most common organisms causing the infection, antibiotics spectrum and minimum inhibitory concentrations (MIC). A search of the physico-chemical properties of antibiotics was performed to calculate the diffusion coefficients. An estimation of the antibiotic concentrations in pancreatic tissue was obtained using a mathematical model. Efficacy factors (EF) were calculated and the stability of the antibiotic solutions were evaluated to optimize the dosing regimen.

RESULTS

Piperacillin, vancomycin and metronidazole achieve high concentrations in the surrounding tissue very fast. Imipenem, ceftriaxone, ciprofloxacin, gentamicin, linezolid and cloxacillin achieve intermediate concentration values. Tigecycline, showed the lowest concentration values (<2 mg/L). Calculated EF is highest for piperacillin and imipenem short after administration and near to surface diffusion area (0.5 cm), but EF of imipenem is higher at deeper areas and longer time after administration.

CONCLUSIONS

Considering obtained results, some solutions are proposed using saline as diluent and 25 °C of temperature during administration. Imipenem has the best theoretical results in empiric local treatment. Linezolid and tigecycline solutions are not recommended.

Orally Administered Salacia reticulata Extract Reduces H1N1 Influenza Clinical Symptoms in Murine Lung Tissues Putatively Due to Enhanced Natural Killer Cell Activity

Influenza is a major cause of respiratory tract infection. Although most cases do not require further hospitalization, influenza periodically causes epidemics in humans that can potentially infect and kill millions of people. To countermeasure this threat, new vaccines need to be developed annually to match emerging influenza viral strains with increased resistance to existing vaccines. Thus, there is a need for finding and developing new anti-influenza viral agents as alternatives to current treatments. Here, we tested the antiviral effects of an extract from the stems and roots of Salacia reticulata (SSRE), a plant rich in phytochemicals, such as salacinol, kotalanol, and catechins, on H1N1 influenza virus-infected mice. Following oral administration of 0.6 mg/day of SSRE, the incidence of coughing decreased in 80% of mice, and only one case of severe pulmonary inflammation was detected. Moreover, when compared with mice given Lactobacillus casei JCM1134, a strain previously shown to help increase in vitro natural killer (NK) cell activity, SSRE-administered mice showed greater and equal NK cell activity in splenocytes and pulmonary cells, respectively, at high effector cell:target cell ratios. Next, to test whether or not SSRE would exert protective effects against influenza in the absence of gut microbiota, mice were given antibiotics before being inoculated influenza virus and subsequently administered SSRE. SSRE administration induced an increase in NK cell activity in splenocytes and pulmonary cells at levels similar to those detected in mice not treated with antibiotics. Based on our results, it can be concluded that phytochemicals in the SSRE exerted protective effects against influenza infection putatively via modulation of the immune response, including enhancement of NK cell activity, although some protective effects were not necessarily through modulation of gut microbiota. Further investigation is necessary to elucidate the molecular mechanisms underlying the protective effects of SSRE against influenza infection.