Bacterial Adherence and the Glycocalyx and Their Role in Musculoskeletal Infection

Enhancing treatment outcomes for Acute Periprosthetic Hip Joint infection: optimizing debridement, antibiotics, and Implant Retention through vacuum sealing drainage in the deep tissue

BACKGROUND

Debridement, antibiotics, and implant retention (DAIR) for acute periprosthetic joint infection (PJI) is under debated since the reported success rate is inconsistent. This study aimed to explore the efficacy of vacuum sealing drainage (VSD) used as an adjunct to irrigation and debridement for acute PJI.

METHODS

Patients undergoing debridement, irrigation with component retention, and application of vacuum seal drainage in the deep portion surrounding the infected sites from January 2014 to February 2021 were retrospectively reviewed. The definition of failure included the requirement of prosthesis removal; persistent infection-related symptoms; suppressive antibiotics therapy due to failure of controlling the infection; infection-related death.

RESULTS

45 patients were included in this study with a mean follow-up of 45.62 ± 13.87 months. There were 28 males and 17 females with a mean age of 63.29 ± 17.74 months. The overall success rate was 86.67% with 6 failures. Multivariate analysis revealed a significant association between Charlson comorbidity index and treatment failure (OR = 2.226, 95% CI, 1.057-4.687, p = 0.035).

CONCLUSIONS

The incorporation of VSD in the deeper region enhances the outcomes of DAIR, achieving an 86.67% success rate in managing acute PJI. This approach offers a potentially safe and effective treatment, though patients with higher Charlson comorbidity index and elevated preoperative CRP levels face increased risks of failure.

What Factors Affect Outcome in the Treatment of Fracture-Related Infection?

This international, multi-center study investigated the effect of individual components of surgery on the clinical outcomes of patients treated for fracture-related infection (FRI). All patients with surgically treated FRIs, confirmed by the FRI consensus definition, were included. Data were collected on demographics, time from injury to FRI surgery, soft tissue reconstruction, stabilization and systemic and local anti-microbial therapy. Patients were followed up for a minimum of one year. In total, 433 patients were treated with a mean age of 49.7 years (17−84). The mean follow-up time was 26 months (range 12−72). The eradication of infection was successful in 86.4% of all cases and 86.0% of unhealed infected fractures were healed at the final review. In total, 3.3% required amputation. The outcome was not dependent on age, BMI, the presence of metalwork or time from injury (recurrence rate 16.5% in FRI treated at 1−10 weeks after injury; 13.1% at 11−52 weeks; 12.1% at >52 weeks: p = 0.52). The debridement and retention of a stable implant (DAIR) had a failure rate of 21.4%; implant exchange to a new internal fixation had a failure rate of 12.5%; and conversion to external fixation had a failure rate of 10.3% (adjusted hazard ratio (aHR) DAIR vs. Ext Fix 2.377; 95% C.I. 0.96−5.731). Tibial FRI treated with a free flap was successful in 92.1% of cases and in 80.4% of cases without a free flap (HR 0.38; 95% C.I. 0.14−1.0), while the use of NPWT was associated with higher recurrence rates (HR 3.473; 95% C.I. 1.852−6.512). The implantation of local antibiotics reduced the recurrence from 18.7% to 10.0% (HR 0.48; 95% C.I. 0.29−0.81). The successful treatment of FRI was multi-factorial. These data suggested that treatment decisions should not be based on time from injury alone, as other factors also affected the outcome. Further work to determine the best indications for DAIR, free flap reconstruction and local antibiotics is warranted.

Nanocarriers for combating biofilms: advantages and challenges

Bacterial biofilms are highly resistant to antibiotics and pose a great threat to human and animal health. The control and removal of bacterial biofilms have become an important topic in the field of bacterial infectious diseases. Nanocarriers show great anti-biofilm potential because of their small particle size and strong permeability. In this review, the advantages of nanocarriers for combating biofilms are analyzed. Nanocarriers can act on all stages of bacterial biofilm formation and diffusion. They can improve the scavenging effect of biofilm by targeting biofilm, destroying extracellular polymeric substances, and enhancing the biofilm permeability of antimicrobial substances. Nanocarriers can also improve the antibacterial ability of antimicrobial drugs against bacteria in biofilm by protecting the loaded drugs and controlling the release of antimicrobial substances. Additionally, we emphasize the challenges faced in using nanocarrier formulations and translating them from a preclinical level to the clinical setting.

The "Torment" of Surgical Antibiotic Prophylaxis among Surgeons

Surgical antibiotic prophylaxis (SAP) is one of the peri-operative measures for preventing surgical site infections (SSIs). Its goal is to counteract the proliferation of bacteria in the surgical site during intervention in order to reduce the risk of SSIs. SAP should be administered for surgical interventions where the benefit expected (prevention of SSIs) is higher compared to the risk (serious side effects, such as acute kidney injury, Clostridioides difficile infection, and the spread of antimicrobial resistance). In prescribing SAP, surgeons should have both the awareness necessary “to handle antibiotics with care”, and the knowledge required to use them appropriately.

Back to Basics: Choosing the Appropriate Surface Disinfectant

From viruses to bacteria, our lives are filled with exposure to germs. In built environments, exposure to infectious microorganisms and their byproducts is clearly linked to human health. In the last year, public health emergency surrounding the COVID-19 pandemic stressed the importance of having good biosafety measures and practices. To prevent infection from spreading and to maintain the barrier, disinfection and hygiene habits are crucial, especially when the microorganism can persist and survive on surfaces. Contaminated surfaces are called fomites and on them, microorganisms can survive even for months. As a consequence, fomites serve as a second reservoir and transfer pathogens between hosts. The knowledge of microorganisms, type of surface, and antimicrobial agent is fundamental to develop the best approach to sanitize fomites and to obtain good disinfection levels. Hence, this review has the purpose to briefly describe the organisms, the kind of risk associated with them, and the main classes of antimicrobials for surfaces, to help choose the right approach to prevent exposure to pathogens.

The Influence of Multidrug-Resistant Bacteria on Clinical Outcomes of Diabetic Foot Ulcers: A Systematic Review

Multidrug-resistant organism infections have become important in recent years due to the increased prevalence of diabetic foot ulcers and their possible consequences. This study aimed to systematically review and evaluate ulcer duration, healing time, hospital stay, amputation, and mortality rates in patients with diabetic foot ulcers caused by infection with multidrug-resistant organisms. PubMed, the Cochrane Library, and Web of Science were searched in May 2020 to find observational studies in English about the clinical outcomes of multidrug-resistant organism infection in diabetic foot ulcers. Eight studies met the inclusion criteria, and these studies included 923 patients. The overall methodological quality of the study was moderate. Ulcer duration was described in six studies, and there was no practical association with multidrug-resistant organisms. Two out of three studies reported a longer healing time in multidrug-resistant organism infections than in non-multidrug-resistant organism infections. Clinical outcomes included the duration of hospitalisation, surgeries, amputations, and deaths. Lower limb amputation was the most reported clinical outcome in the included studies, and was more prevalent in the multidrug-resistant organism infections. We concluded that there was not enough evidence that multidrug-resistant organisms hindered the healing of diabetic foot ulcers. In contrast to the clinical outcomes, multidrug-resistant organisms affect both amputation rates and mortality rates.

Outcome of Irrigation and Debridement With Topical Antibiotics Delivery for the Management of Periprosthetic Joint Infection Occurring Within 3 Months Since the Primary Total Joint Arthroplasty

BACKGROUND

Irrigation and debridement with modular component exchange is appealing for surgeons to treat early-stage periprosthetic joint infection (PJI). However, the indication, perioperative protocol, and success rate remain controversial. This study is the first one to present results of debridement, antibiotics, and implant retention (DAIR) with integrated MIT (modular component exchange, povidone-iodine and topical antibiotics delivery) protocol for treating PJI occurring within 3 months since the primary total joint arthroplasty.

METHODS

We retrospectively analyzed patients who received DAIR with MIT protocol in our department between January 2011 and May 2018. Topical antibiotics were delivered in all cases. Topical antibiotics infusion was applied for those infected with multidrug-resistant bacteria, fungus, polymicrobial infection, and culture negative one. Failure was defined as additional surgical intervention for infection after DAIR; persistent sinus tract, drainage or excessive joint pain; need for suppressive antibiotics therapy due to the infection; infection relapse with the same pathogen; reinfection with different microorganism; and infection-related death.

RESULTS

A total of 73 patients with a mean age of 63.30 ± 10.97 years were included in this study, including 43 men and 30 women. There are 41 knees and 32 hips. Thirty patients had sinus tract. With a mean follow-up of 63.79 ± 18.57 months, there were 9 failures in total with an overall success rate of 87.67%. The success rate was 88.57% and 86.84% for those receiving topical antibiotics infusion postoperatively and those without.

CONCLUSIONS

DAIR with a standard MIT protocol is a viable and safe option for PJI occurring within 3 months since the primary total joint arthroplasty.

LEVEL OF EVIDENCE

Level 4, therapeutic study.

Reconstruction of infected post-traumatic bone defects of the distal femur with the CompressⓇ implant. Preliminary results of a staged non-biological strategy

INTRODUCTION

Infected post-traumatic distal femur defects remain a therapeutic challenge. Non-biological reconstruction offers an option for avoiding complex biological knee arthrodesis procedures. The Compress^Ⓡ implant is an alternative to the traditional distal femur stemmed megaprosthesis. The aim of this study is to analyse the first patients treated with a distal femur Compress^Ⓡ prosthesis to manage massive infected post-traumatic defects of the distal femur with joint involvement.

METHODS

We retrospectively reviewed all patients with massive infected defects of the distal femur where this implant was used in a two-stage strategy, together with an antibacterial coating hydrogel (DAC^Ⓡ). The specific protocol, microbiological data, clinical and radiological results, complications, functional results and prosthesis survivorship were determined. Follow-up was for a minimum of 12 months, or until implant removal.

RESULTS

Ten patients (11 Compress^Ⓡ implants) with a mean age of 52 years (range 35-73) were included. On average, patients had undergone 4.4 previous surgical procedures before index surgery. The mean bone defect was 14 cm (range 8-21). After a median follow-up of 27 months (range 12-50 months) no patient had presented with recurrence of the infection, and limb salvage was achieved in all cases. Two patients suffered aseptic loosening which required revision of the femoral component. The short-term survivorship of the implant in our series was 81.8% at 4 years, with all failures occurring in the first 7 months. After this 7-month time threshold, we encountered no further loosening. Regarding functional outcomes, patients had a mean knee ROM of -4/86, expressed high overall satisfaction with the procedure according to the SAPS scale, and had an average LEFS of 52.5% (40-72.5%).

CONCLUSION

Non-biological reconstruction of the distal femur with the Compress^Ⓡ implant is a valid option in selected patients with massive infected defects with joint involvement. Survivorship was high, with all loosening occurring in the first months after surgery-representing a failure in the osseointegration of the implant.

Bone mineral as a drug-seeking moiety and a waste dump

Bone is a dynamic tissue with a quarter of the trabecular and a fifth of the cortical bone being replaced continuously each year in a complex process that continues throughout an individual's lifetime. Bone has an important role in homeostasis of minerals with non-stoichiometric hydroxyapatite bone mineral forming the inorganic phase of bone. Due to its crystal structure and chemistry, hydroxyapatite (HA) and related apatites have a remarkable ability to bind molecules. This review article describes the accretion of trace elements in bone mineral giving a historical perspective. Implanted HA particles of synthetic origin have proved to be an efficient recruiting moiety for systemically circulating drugs which can locally biomodulate the material and lead to a therapeutic effect. Bone mineral and apatite however also act as a waste dump for trace elements and drugs, which significantly affects the environment and human health. Cite this article: Bone Joint Res 2020;9(10):709-718.

Comprehensive structural glycomic characterization of the glycocalyxes of cells and tissues

The glycocalyx comprises glycosylated proteins and lipids and fcorms the outermost layer of cells. It is involved in fundamental inter- and intracellular processes, including non-self-cell and self-cell recognition, cell signaling, cellular structure maintenance, and immune protection. Characterization of the glycocalyx is thus essential to understanding cell physiology and elucidating its role in promoting health and disease. This protocol describes how to comprehensively characterize the glycocalyx N-glycans and O-glycans of glycoproteins, as well as intact glycolipids in parallel, using the same enriched membrane fraction. Profiling of the glycans and the glycolipids is performed using nanoflow liquid chromatography-mass spectrometry (nanoLC-MS). Sample preparation, quantitative LC-tandem MS (LC-MS/MS) analysis, and data processing methods are provided. In addition, we discuss glycoproteomic analysis that yields the site-specific glycosylation of membrane proteins. To reduce the amount of sample needed, N-glycan, O-glycan, and glycolipid analyses are performed on the same enriched fraction, whereas glycoproteomic analysis is performed on a separate enriched fraction. The sample preparation process takes 2-3 d, whereas the time spent on instrumental and data analyses could vary from 1 to 5 d for different sample sizes. This workflow is applicable to both cell and tissue samples. Systematic changes in the glycocalyx associated with specific glycoforms and glycoconjugates can be monitored with quantitation using this protocol. The ability to quantitate individual glycoforms and glycoconjugates will find utility in a broad range of fundamental and applied clinical studies, including glycan-based biomarker discovery and therapeutics.

Graft-Preserving Arthroscopic Debridement With Hardware Removal Is Effective for Septic Arthritis After Anterior Cruciate Ligament Reconstruction: A Clinical, Arthrometric, and Magnetic Resonance Imaging Evaluation

BACKGROUND

Arthroscopic debridement with graft preservation has been advocated as the treatment of choice for septic arthritis after anterior cruciate ligament (ACL) reconstruction, but no previous studies have investigated if hardware removal, while retaining the graft in situ, improves the success rate. Moreover, it is unclear whether the premature removal of fixation devices may affect graft integration and knee stability.

PURPOSE/HYPOTHESIS

The purpose was to assess the clinical and functional outcomes of patients with septic arthritis after ACL reconstruction who underwent arthroscopic debridement, while retaining the graft in situ but removing fixation devices, and to determine if premature hardware removal affects graft integrity and function. The hypothesis was that arthroscopic debridement with hardware removal would be effective in eradicating infections while not compromising graft integration and function.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From a cohort of 2384 cases of arthroscopic ACL reconstruction, 24 patients with postoperative septic arthritis were included for the analysis; 18 patients were available for a clinical evaluation using the International Knee Documentation Committee (IKDC) form, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Lysholm score, and Tegner score at a minimum 12-month follow-up. Knee laxity was assessed clinically with standardized manual laxity tests and instrumentally using an arthrometer and a triaxial accelerometer. Additionally, 3-T magnetic resonance imaging (MRI) at final follow-up was performed, focusing on the graft signal, the cartilage status, and the occurrence of arthrofibrosis.

RESULTS

Eradication of the infection was achieved in all cases, and only 1 graft removal was performed because of insufficient tension. Among the remaining 23 patients, a single arthroscopic debridement procedure with hardware removal while preserving the graft was effective in 21 cases (91%) at a mean of 30 ± 37 days from ACL reconstruction to debridement. At last follow-up, 2 patients required a further ACL revision procedure. The mean IKDC, WOMAC, Lysholm, and Tegner scores of the patients available for the clinical evaluation were 75 ± 19, 90 ± 8, 79 ± 21, and 6 ± 2, respectively. No abnormal laxity was reported on manual testing, and arthrometric and accelerometer tests also demonstrated good knee stability (mean KT-1000 arthrometer side-to-side difference was 1.6 ± 1.2 mm at manual maximum force). On MRI, a good graft signal was found in 50% of cases, while concomitant signs of arthrofibrosis were detected in 81% of patients. Severe cartilage defects (International Cartilage Repair Society grade ≥3) were reported in 63% of cases.

CONCLUSION

Arthroscopic debridement with hardware removal was effective in the eradication of infections after ACL reconstruction with extra-articular fixation while preserving graft integrity without compromising knee stability. Patients and surgeons should be aware of complications that might affect the outcome, particularly arthrofibrosis and chondrolysis.

Time-dependent surgical instrument contamination begins earlier in the uncovered table than in the covered table

PURPOSE

Time-dependent surgical instrument contamination and the effect of covering during arthroplasty have not been investigated. This study aimed to evaluate time-dependent contamination of surgical instruments and the effect of covering on contamination as well as to perform bacterial typing of contaminated samples. The hypothesis was that covering the surgical instruments would decrease contamination rates.

METHODS

Sixty patients who underwent total knee arthroplasty were randomized and divided into two groups: surgical instruments covered with a sterile towel or surgical instruments left uncovered. K-wires were used to extract microbiological samples. The K-wires were placed in a liquid culture medium at 0, 15, 30, 60, 90, and 120 min. After 24-h incubation period, samples from liquid cultures were cultured on blood agar using swabs. Samples with growth after 48 h were considered contaminated. Microscopic, staining, and biochemical properties were used for bacterial typing.

RESULTS

Bacterial growth started after 30 and 60 min in the uncovered and covered groups, respectively. An increase in the number of K-wires contaminated with time was detected. At least 10,000 CFU/mL bacterial load was observed in the culture samples. Contamination was more significant in the uncovered group. A statistically significant difference in contamination was found between the uncovered and covered groups at 30-, 60-, 90-, and 120 min (p = 0.035, p = 0.012, p = 0.024, and p = 0.037, respectively). The most common bacteria on the contaminated instruments were coagulase-negative Staphylococci (60.4%), Staphylococcus aureus (22.9%), and Streptococcus agalactia (16.7%), respectively.

CONCLUSION

The risk of contamination increases with time. However, it may decrease if surgical instruments are covered. In the clinical practice, empiric antibiotic regimens based on the type of identified microorganisms in this study may be developed for postoperative periprosthetic joint infection prophylaxis.

LEVEL OF EVIDENCE

Prognostic, Level II.

Endothelial glycocalyx in acute care surgery - what anaesthesiologists need to know for clinical practice

The endothelial glycocalyx (EG) is the thin sugar-based lining on the apical surface of endothelial cells. It has been linked to the physiological functioning of the microcirculation and has been found to be damaged in critical illness and after acute care surgery. This review aims to describe the role of EG in severely injured patients undergoing surgery, discuss specific situations (e.G. major trauma, hemorrhagic shock, trauma induced coagulopathy) as well as specific interventions commonly applied in these patients (e.g. fluid therapy, transfusion) and specific drugs related to perioperative medicine with regard to their impact on EG.EG in acute care surgery is exposed to damage due to tissue trauma, inflammation, oxidative stress and inadequate fluid therapy. Even though some interventions (transfusion of plasma, human serum albumin, hydrocortisone, sevoflurane) are described as potentially EG protective there is still no specific treatment for EG protection and recovery in clinical medicine.The most important principle to be adopted in routine clinical practice at present is to acknowledge the fragile structure of the EG and avoid further damage which is potentially related to worsened clinical outcome.

Bacterial osteomyelitis in veterinary orthopaedics: Pathophysiology, clinical presentation and advances in treatment across multiple species

Bacterial osteomyelitis in veterinary patients can be challenging to diagnose and treat, given limited therapeutic options and reported success rates. Osteomyelitis is frequently associated with surgical implant devices, including those required to optimise stability and healing of fractures. However, management of osteomyelitis sometimes necessitates the removal of these surgical implant devices in order to eradicate infection or limit implant-related osteolysis. The goal of this article is to provide a general and species-specific review of bacterial osteomyelitis in a selection of domestic veterinary species, including cats, dogs, horses, cattle and camelids, with a focus on classification, clinical presentation, aetiologic agents, and common therapeutic interventions reported in the literature. New treatment options emerging from research and human medicine will be also discussed, as they also apply to current or future care of veterinary patients with osteomyelitis.

Non-union: Indications for external fixation

External fixation is currently used as the definitive mode of fracture stabilisation in the management of ˜50% of long-bone non-unions. Distinction between non-union and delayed union is a diagnostic dilemma especially in fractures healing by primary bone repair. This distinction is important, as non-unions are not necessarily part of the same spectrum as delayed unions. The aetiology of a fracture non-union is usually multifactorial and the factors can be broadly categorized into mechanical factors, biological (local and systemic) factors, and infection. Infection is present in ˜40% of fracture non-unions, often after open fractures or impaired wound healing, but in 5% of all non-unions infection is present without any clinical or serological suspicion. General indications for external fixation include clinical scenarios where; 1) percutaneous correction of alignment, or mechanical stimulation of the non-union site is required; 2) fixation of juxta-articular or 'emmental' bone fragments is necessary; and 3) staged bone or soft tissue reconstruction is anticipated. Specific anatomical indications include infected non-unions of the tibia, humerus, and juxta-articular bone. External fixation is an essential tool in the management of fracture non-unions. However, with greater understanding of the outcomes associated with both external and internal fixation the relative indications are now being refined.

Treatment of Prosthetic Joint Infection with Debridement, Antibiotics and Irrigation with Implant Retention - a Narrative Review

Prosthetic joint infection usually requires combined medical and surgical therapy. While revision surgery is widely considered to be the gold standard surgical procedure, debridement, antibiotics and irrigation with implant retention is a very appealing alternative. There is however great controversy regarding its real worth with success rates ranging from 0% to over 90%. A number of different patient and host related variables as well as specific aspects of surgical and medical management have been described as relevant for the final outcome. Along this paper, the authors will provide the readers with a critical narrative review of the currently available literature while trying to provide concise and practical treatment recommendations regarding adequate patient selection criteria, proper surgical technique and optimal antibiotic therapy.

Non-union after plate fixation

Approximately a third of patients presenting with long-bone non-union have undergone plate fixation as their primary procedure. In the assessment of a potential fracture non-union it is critical to understand the plating technique that the surgeon was intending to achieve at the primary procedure, i.e. whether it was direct or indirect fracture repair. The distinction between delayed union and non-union is a diagnostic dilemma especially in plated fractures, healing by primary bone repair. The distinction is important as nonunions are not necessarily part of the same spectrum as delayed unions. The etiology of a fracture non-union is usually multifactorial and the factors can be broadly categorized into mechanical factors, biological (local and systemic) factors, and infection. Infection is present in ~40% of fracture non-unions, often after open fractures or impaired wound healing, but in 5% of all non-unions infection is present without any clinical or serological suspicion. Methods to improve the sensitivity of investigation in the search of infection include the use of; sonication of implants, direct inoculation of theatre specimens into broth, and histological examination of non-union site tissue. Awareness should be given to the potential anti-osteogenic effect of bisphosphonates (in primary fracture repair) and certain classes of antibiotics. Early cases of delayed/non-union with sufficient mechanical stability and biologically active bone can be managed by stimulation of fracture healing. Late presenting non-union typically requires revision of the fixation construct and stimulation of the callus to induce fracture union.

[Infected osteosynthesis]

BACKGROUND

Infections after osteosynthesis are a feared complication of the surgical treatment of fractures and should be dealt with by a multidisciplinary team. In addition to the surgeon, also included in this multidisciplinary team are a specialist for infectious diseases, a microbiologist, a radiologist and often a plastic surgeon. This review article describes the current knowledge on the pathogenesis, diagnostics, classification and treatment. The aim is to demonstrate some basic rules in the treatment of infections associated with implants and to show potential therpeutic approaches.

MATERIAL AND METHODS

The principles of diagnostics and combined surgical and antibiotic treatment are presented based on the current specialist literature.

RESULTS

With the help of a team approach the goals of treatment of an infected osteosynthesis, i.e. fracture healing, return to function and eradication of infection can be achieved. While the osteosynthesis material can usually be retained in acute infections, it is better to remove the infected hardware in chronic infections as eradication of the mature biofilm is no longer possible.

DISCUSSION

With adequate local wound débridement, the use of local and systemic antibiotics, as indicated by the specialist for infectious diseases and appropriate soft tissue coverage and wound closure, acute as well as chronic infections can be successfully treated. Nowadays, the surgeon has many different options for the management of bone defects. Depending on the anatomical location and the size of the defect a variety of techniques ranging from acute shortening to the Masquelet technique up to the Ilizarov distraction technique are available. These techniques should be combined with local bactericidal treatment.

Animal Models of Osteomyelitis

There are numerous reports in the literature using animal models of osteomyelitis for investigating pathogenesis, diagnosis, and treatment of bone infections. Rabbits, rats, and dogs are commonly used animals, and, less frequently, chickens, guinea pigs, miniature pigs, goats, and sheep. Commonly used bones for creating local osteomyelitis include tibia, femur, and radius, and, less frequently, mandible and spine. When designing a specific model, one should consider which animal and which bone will be used, which route for inoculation (either local injection or systemically through vascular injection), which bacterial species and how many bacteria should be applied, if and what sclerosing agent, foreign body or implant should be employed, and if local trauma is needed. Basic methods of evaluation include clinical observation, radiography, microbiology, and histology.

Tibial plateau levelling osteotomy implant removal: A retrospective analysis of 129 cases

Objective: To evaluate a cohort of dogs undergoing tibial plateau levelling osteotomy (TPLO) implant removal to determine key clinical features, prevalence, and indications for implant removal.

Methods: Medical records of dogs undergoing TPLO implant removal at a private referral practice (Dallas Veterinary Surgical Center) between 2004–2008 were reviewed. Patient signalment, implant type, presence of concurrent medical disease, surgeon, antibiotic use, aerobic bacterial culture result, and operative findings were recorded. Data were analyzed using paired t-test, Fisher’s exact test, and Wilcoxon-rank sum test. Statistical significance was set at p <0.05.

Results: The TPLO implants were removed from 126 dogs (n = 129, 4.8% of TPLO procedures) during the study period. Average time interval from TPLO to implant removal was 16.0 ± 17.8 months. The most common clinical signs were the presence of an open wound (n = 80), draining tract (n = 64), and lameness (n = 59). Culture of tissue or fluid from the implant bed or implants was positive for bacterial growth in 95/115 cases. A significantly greater proportion of the implants removed were Slocum TPLO plates (n = 109 6.1%) when compared to other TPLO plate types (n = 20 2.3%) (p <0.0001). No association was identified between a positive bacterial culture and measured variables.

Clinical significance: Local bacterial infection and clinical signs of inflammation were the most common reasons for TPLO implant removal. There may be an increased implant-associated complication rate for Slocum TPLO plates in the study population.

Outcomes following debridement, antibiotics and implant retention in the management of periprosthetic infections of the hip: a review of cohort studies

AIMS

The aims of the study were to review and analyse the reported series of debridement, antibiotics and implant retention (DAIR) in the management of infected total hip arthroplasties (THAs) to establish the overall success and the influencing factors.

PATIENTS AND METHODS

Using a standardised recognised study protocol, meta-analysis of observational studies in epidemiology guidelines, a comprehensive review and analysis of the literature was performed. The primary outcome measure was the success of treatment. The search strategy and inclusion criteria which involved an assessment of quality yielded 39 articles for analysis, which included 1296 patients.

RESULTS

The proportion of success following DAIR in the management of an infected THA appeared to improve after 2004 with a pooled mean proportion of success of 72.2%. For all reported series, from 1977 onwards, there was improved success with early debridement (< 7 days; 75.7%) and exchange of modular components (77.5%). There was a statistically non-significant improvement if debridement was performed within four weeks of the initial procedure (73.0%).

CONCLUSION

The reported success following DAIR has improved since 2004. The only determinants of outcome which we found were the timing of debridement after the onset of symptoms of infection and the exchange of modular components. Cite this article: Bone Joint J 2017;99-B:1488-66.

Plasticity of Candida albicans Biofilms

Candida albicans, the most pervasive fungal pathogen that colonizes humans, forms biofilms that are architecturally complex. They consist of a basal yeast cell polylayer and an upper region of hyphae encapsulated in extracellular matrix. However, biofilms formed in vitro vary as a result of the different conditions employed in models, the methods used to assess biofilm formation, strain differences, and, in a most dramatic fashion, the configuration of the mating type locus (MTL). Therefore, integrating data from different studies can lead to problems of interpretation if such variability is not taken into account. Here we review the conditions and factors that cause biofilm variation, with the goal of engendering awareness that more attention must be paid to the strains employed, the methods used to assess biofilm development, every aspect of the model employed, and the configuration of the MTL locus. We end by posing a set of questions that may be asked in comparing the results of different studies and developing protocols for new ones. This review should engender the notion that not all biofilms are created equal.

In vivo bactericidal efficacy of the Ti6Al4V surface after ultraviolet C treatment

Background

Biomaterial-associated infections are one of the most important complications in orthopedic surgery. The main goal of this study was to demonstrate the in vivo bactericidal effect of ultraviolet (UV) irradiation on Ti6Al4V surfaces.

Materials and methods

An experimental model of device-related infections was developed by direct inoculation of Staphylococcus aureus into the canal of both femurs of 34 rats. A UV-irradiated Ti6Al4V pin was press-fit into the canal by retrograde insertion in one femur and the control pin was inserted into the contralateral femur. To assess the efficacy of UV radiation, the mean colony counts after inoculation in the experimental subjects and the control group were compared at different times of sacrifice and at different inoculum doses.

Results

At 72 h, the mean colony counts after inoculation in experimental femurs were significantly lower than those of the control group, with a reduction percentage of 76 % (p = 0.041). A similar difference between control and experimental pins was observed at 24 h using an inoculum dose <10⁴ colony-forming units (CFU), for which the reduction percentage was 70.48 % (p = 0.017).

Conclusion

The irradiated surface of Ti6Al4V is able to reduce early bacterial colonization of Ti6AlV pins located in the medullar channel and in the surrounding femur. The reductions depend on the initial inoculums used to cause infection in the animals and the greatest effects are detected for inoculums <10⁴ CFU.

Level of evidence

Not applicable.

Evaluation of the Time-dependent Contamination of Spinal Implants: Prospective Randomized Trial

STUDY DESIGN

Prospective study OBJECTIVE.: To evaluate contamination in spinal implants using a liquid culture medium and the effect of covering an implant set on contamination.

SUMMARY OF BACKGROUND DATA

Postoperative infection rates increase with the use of spinal implants. Because implant contamination may be an important origin for postoperative infections, investigation, evaluation, and taking required precautions to prevent these contaminations are critical.

METHODS

Patients operated on for various spinal pathologies were randomized. The patients were divided into groups of covered and uncovered implant sets. The screw samples were placed in liquid culture medium immediately after opening the implant set. The implant set in the covered group was immediately covered with a sterile surgical towel. A new screw was taken from the implant set and cultured in the liquid culture medium every 30 minutes. At the end of 24 hours, swabs with samples from the liquid culture medium were used to culture blood agar. At the end of 48 hours, the samples with growth were considered contaminated.

RESULTS

Growth started after 30 minutes in the uncovered group, whereas only a single growth was noted after 60 minutes in the covered group. Contamination increased with time in both groups, but more so in the open group. A statistically significant difference in contamination was found between the groups at and after 30 minutes.

CONCLUSION

Contamination increases with time in all implant materials. Contamination rates can be reduced by using simple precautions, such as covering the implant set. Culturing the entire implant samples in liquid culture medium is accepted as a safe and more effective method in evaluating contamination.

LEVEL OF EVIDENCE

2.

Polysaccharide intercellular adhesin in biofilm: structural and regulatory aspects

Staphylococcus aureus and Staphylococcus epidermidis are the leading etiologic agents of implant-related infections. Biofilm formation is the main pathogenetic mechanism leading to the chronicity and irreducibility of infections. The extracellular polymeric substances of staphylococcal biofilms are the polysaccharide intercellular adhesin (PIA), extracellular-DNA, proteins, and amyloid fibrils. PIA is a poly-β(1-6)-N-acetylglucosamine (PNAG), partially deacetylated, positively charged, whose synthesis is mediated by the icaADBC locus. DNA sequences homologous to ica locus are present in many coagulase-negative staphylococcal species, among which S. lugdunensis, however, produces a biofilm prevalently consisting of proteins. The product of icaA is an N-acetylglucosaminyltransferase that synthetizes PIA oligomers from UDP-N-acetylglucosamine. The product of icaD gives optimal efficiency to IcaA. The product of icaC is involved in the externalization of the nascent polysaccharide. The product of icaB is an N-deacetylase responsible for the partial deacetylation of PIA. The expression of ica locus is affected by environmental conditions. In S. aureus and S. epidermidis ica-independent alternative mechanisms of biofilm production have been described. S. epidermidis and S. aureus undergo to a phase variation for the biofilm production that has been ascribed, in turn, to the transposition of an insertion sequence in the icaC gene or to the expansion/contraction of a tandem repeat naturally harbored within icaC. A role is played by the quorum sensing system, which negatively regulates biofilm formation, favoring the dispersal phase that disseminates bacteria to new infection sites. Interfering with the QS system is a much debated strategy to combat biofilm-related infections. In the search of vaccines against staphylococcal infections deacetylated PNAG retained on the surface of S. aureus favors opsonophagocytosis and is a potential candidate for immune-protection.

Treating periprosthetic joint infections as biofilms: key diagnosis and management strategies

Considerable evidence suggests that microbial biofilms play an important role in periprosthetic joint infection (PJI) pathogenesis. Compared to free-floating planktonic bacteria, biofilm bacteria are more difficult to culture and possess additional immune-evasive and antibiotic resistance mechanisms, making infections harder to detect and eradicate. This article reviews cutting-edge advances in biofilm-associated infection diagnosis and treatment in the context of current PJI guidelines and highlights emerging technologies that may improve the efficacy and reduce costs associated with PJI. Promising PJI diagnostic tools include culture-independent methods based on sequence comparisons of the bacterial 16S ribosomal RNA gene, which offer higher throughput and greater sensitivity than culture-based methods. For therapy, novel methods based on disrupting biofilm-specific properties include quorum quenchers, bacteriophages, and ultrasound/electrotherapy. Since biofilm infections are not easily detected or treated by conventional approaches, molecular diagnostic techniques and next-generation antibiofilm treatments should be integrated into PJI clinical practice guidelines in the near future.

Revealing a world of biofilms--the pioneering research of Bill Costerton

Bill Costerton is recognized as the founding father of the field of biofilms, which is the study of microorganisms attached to surfaces. He was a true pioneer and was passionate about directly observing living complex microbial communities to learn how they function in different ecosystems. His multidisciplinary approach to the study of biofilms forged a common way of thinking about the ways in which microorganisms survive and function in the environment as well as in medical, dental, industrial, agricultural, engineering and other contexts. In this Essay, we outline some of the achievements that Bill made during his scientific journey.

Clinical Outcomes of Multidrug Resistant Pseudomonas aeruginosa Infection and the Relationship With Type III Secretion System in Patients With Diabetic Foot

The objective was to analyze the clinical outcomes of multidrug resistant Pseudomonas aeruginosa (MDRPA) infection and determine the relationship between type III secretion system (TTSS) and MDRPA in diabetic foot (DF) patients. A total of 117 patients infected with P aeruginosa were recruited and grouped into MDRPA and non-MDRPA group according to antimicrobial susceptibility testing. TTSS genes were detected by polymerase chain reaction (PCR). Potential risk factors for MDRPA infection were examined using univariate and multivariate analyses. Clinical outcomes were compared on the basis of MDRPA or TTSS virulence gene. Previous antibiotic therapy, previous hospitalization and osteomyelitis were associated with MDRPA infection. MDRPA group had a higher amputation/toe rate (32.6% vs 16.2%) and lower healing rate (20.9% vs 41.9%) than non-MDRPA group ( P = .032). A significantly higher proportion of exoU was present in MDRPA group (75.0% vs 25.0%, P < .05) than non-MDRPA group. Patients infected with exoU isolates had a lower healing rate and higher amputation/toe rate (25.0% vs 65.2%, 33.3% vs 8.7%, P < .05) than infected with exoS isolates. The exoU gene was predominance among MDRPA strains. The poor clinical outcomes of MDRPA infection in patients with DF were attributable to exoU gene.

Multiple arthroscopic debridement and graft retention in septic knee arthritis after ACL reconstruction: a prospective case-control study

PURPOSE

This study was undertaken to prospectively analyse, at a mean five-year follow-up, the clinical, functional, and radiographic outcomes in patients who developed postoperative acute septic knee arthritis following anterior cruciate ligament (ACL) reconstruction using hamstring autograft. We also assessed the effect of multiple arthroscopic debridement and graft retention on the functional outcomes in comparison with the matched control group.

METHODS

From a consecutive case series of 2,560 ACL-injured patients who were treated with arthroscopic ACL reconstruction, we report on 24 cases with postoperative septic knee arthritis. These patients were individually matched for age, sex, comorbidity, body mass index (BMI) and preinjury Tegner activity scale in a ratio of 1/1. Clinical, laboratory, synovial fluid analysis and culture were performed. Arthroscopic debridement and graft retention was done for all cases, in addition to antibiotic therapy i.v.. A detailed physical examination, KT1000 laxity testing, Lysholm knee score, Tegner activity level scale, International Knee Documentation Committee (IKDC), and Knee Injury and Osteoarthritis Outcome Score (KOOS) were completed.

RESULTS

In all cases, treatment of infection was successful after a median of three (range one to six) repeated arthroscopic graft debridement and retention, in addition to antibiotic therapy i.v.. At an average of five years follow-up, two patients had over five millimetres manual maximum side-to-side difference in laxity. There were no significant differences between groups regarding Lysholm score, IKDC and KOOS. Median final Tegner activity score was 5.5 versus 7 in the control group (p = 0.004). Complications included graft rupture in three patients, loss of range of motion in five, Sudeck's atrophy in one and moderate joint narrowing in two. There were no recurrences of septic arthritis or bone infection.

CONCLUSION

Graft retention seems not only possible but appropriate in view of the experience presented in this article for postoperative septic knee arthritis using hamstring autograft. A potential residual complication is arthrofibrosis, which deserves maximum attention.

Diagnosis and management of infection in the diabetic foot

Foot infections are common in persons with diabetes mellitus. Most diabetic foot infections occur in a foot ulcer, which serves as a point of entry for pathogens. Unchecked, infection can spread contiguously to involve underlying tissues, including bone. A diabetic foot infection is often the pivotal event leading to lower extremity amputation, which account for about 60% of all amputations in developed countries. Given the crucial role infections play in the cascade toward amputation, all clinicians who see diabetic patients should have at least a basic understanding of how to diagnose and treat this problem.

A silver ion-doped calcium phosphate-based ceramic nanopowder-coated prosthesis increased infection resistance

BACKGROUND

Despite progress in surgical techniques, 1% to 2% of joint arthroplasties become complicated by infection. Coating implant surfaces with antimicrobial agents have been attempted to prevent initial bacterial adhesion to implants with varying success rates. We developed a silver ion-containing calcium phosphate-based ceramic nanopowder coating to provide antibacterial activity for orthopaedic implants.

QUESTIONS/PURPOSES

We asked whether titanium prostheses coated with this nanopowder would show resistance to bacterial colonization as compared with uncoated prostheses.

METHODS

We inserted titanium implants (uncoated [n = 9], hydroxyapatite-coated [n = 9], silver-coated [n = 9]) simulating knee prostheses into 27 rabbits' knees. Before implantation, 5 × 10(2) colony-forming units of Staphylococcus aureus were inoculated into the femoral canal. Radiology, microbiology, and histology findings were quantified at Week 6 to define the infection, microbiologically by increased rate of implant colonization/positive cultures, histologically by leukocyte infiltration, necrosis, foreign-body granuloma, and devitalized bone, and radiographically by periosteal reaction, osteolysis, or sequestrum formation.

RESULTS

Swab samples taken from medullary canals and implants revealed a lower proportion of positive culture in silver-coated implants (one of nine) than in uncoated (eight of nine) or hydroxyapatite-coated (five of nine) implants. Silver-coated implants also had a lower rate of colonization. No cellular inflammation or foreign-body granuloma was observed around the silver-coated prostheses.

CONCLUSIONS

Silver ion-doped ceramic nanopowder coating of titanium implants led to an increase in resistance to bacterial colonization compared to uncoated implants.

CLINICAL RELEVANCE

Silver-coated orthopaedic implants may be useful for resistance to local infection but will require in vivo confirmation.

From in vitro to in vivo Models of Bacterial Biofilm-Related Infections

The influence of microorganisms growing as sessile communities in a large number of human infections has been extensively studied and recognized for 30–40 years, therefore warranting intense scientific and medical research. Nonetheless, mimicking the biofilm-life style of bacteria and biofilm-related infections has been an arduous task. Models used to study biofilms range from simple in vitro to complex in vivo models of tissues or device-related infections. These different models have progressively contributed to the current knowledge of biofilm physiology within the host context. While far from a complete understanding of the multiple elements controlling the dynamic interactions between the host and biofilms, we are nowadays witnessing the emergence of promising preventive or curative strategies to fight biofilm-related infections. This review undertakes a comprehensive analysis of the literature from a historic perspective commenting on the contribution of the different models and discussing future venues and new approaches that can be merged with more traditional techniques in order to model biofilm-infections and efficiently fight them.

Periprosthetic joint infection: Current concept

Periprosthetic joint infection (PJI) is one of the most devastating and costly complications following total joint arthroplasty (TJA). Diagnosis and management of PJI is challenging for surgeons. There is no "gold standard" for diagnosis of PJI, making distinction between septic and aseptic failures difficult. Additionally, some of the greatest difficulties and controversies involve choosing the optimal method to treat the infected joint. Currently, there is significant debate as to the ideal treatment strategy for PJI, and this has led to considerable international variation in both surgical and nonsurgical management of PJI. In this review, we will discuss diagnosis and management of PJI following TJA and highlight some recent advances in this field.

Revision total knee arthroplasty: infection should be ruled out in all cases

We hypothesized that some aseptic revision total knee arthroplasty failures are indeed caused by occult infection. This prospective study recruited 65 patients undergoing revision total knee arthroplasty. The mean follow-up period was 19 months. Collected synovial fluid was analyzed by Ibis T5000 biosensor (Abbott Molecular Inc, Ill; a multiplex polymerase chain reaction technology). Cases were considered as infected or aseptic based on the surgeon's judgment and Ibis findings. Based on Ibis biosensor, 17 aseptic cases were indeed infected that had been missed. Of these 17 cases, 2 developed infection after the index revision. A considerable number of so-called aseptic failures seem to be occult infections that were not adequately investigated and/or miscategorized as aseptic failure. We recommend that all patients undergoing revision arthroplasty be investigated for periprosthetic joint infection.

Aseptic loosening of total hip arthroplasty: infection always should be ruled out

BACKGROUND

It is believed that some cases of aseptic failure of THA may be attributable to occult infections. However, it is unclear whether preoperative erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are more likely elevated in these patients than those without overt infection.

QUESTIONS/PURPOSES

We asked whether some patients with aseptic THA failures have abnormal serologic indicators of periprosthetic joint infection (PJI) at the time of revision, namely ESR and/or CRP.

METHODS

Three hundred twenty-three revision THAs for aseptic loosening from 2004 to 2007 were retrospectively evaluated. We categorized all cases into two groups: (1) those with overt PJI (n = 14) plus patients who had a positive intraoperative culture during the index revision (n = 13) and (2) those who did not require rerevision (n = 276) or required surgery for noninfected causes (n = 20). Mean and frequency of abnormal ESR and CRP were compared between the two groups. The minimum followup was 11 months (average, 35 months; range, 11-54 months).

RESULTS

The mean and frequency of abnormal CRP in first group (n = 27) at 2.1 mg/dL and 48% respectively, were greater than those of the uninfected (n = 296) at 1.2 mg/dL and 27%, respectively. However, there were no differences between two groups regarding mean or frequency of abnormal ESR.

CONCLUSION

Some patients with presumed aseptic loosening may have abnormal serologic indicators of PJI that either have escaped diagnosis or were not adequately investigated. All patients undergoing revision THA should have ESR and CRP measured preoperatively and those with abnormal CRP should have additional evaluations to rule out or confirm PJI.

Bone and joint infections in adults: a comprehensive classification proposal

Introduction and methods

Ten currently available classifications were tested for their ability to describe a continuous cohort of 300 adult patients affected by bone and joint infections. Each classification only focused, on the average, on 1.3 ± 0.4 features of a single clinical condition (osteomyelitis, implant-related infections, or septic arthritis), being able to classify 34.8 ± 24.7% of the patients, while a comprehensive classification system could describe all the patients considered in the study.

Result and conclusion

A comprehensive classification system permits more accurate classification of bone and joint infections in adults than any single classification available and may serve for didactic, scientific, and clinical purposes.

Hydroxylapatite Silver Phosphate Ceramics: Production, Analysis and Biological Testing of their Antibacterial Effectiveness

One important, and perhaps the crucial reason for lack of success in permanent implants is their colonization by bacteria (ref. 1,2 ). There are various reports of bacteria lodging the surface implants and their success in escaping from the host's defense mechanisms. Quantitative studies of ecosystems have established that more than 99,9% of the bacteria within the system live in microcolonies within biofilms that are adherent to inert surfaces ( ref. 3,4 ). Many of the bacteria that colonize the surfaces of clinical biomaterials also grow in thick, adherent biofilms ( 10, 11 ). - They may be introduced when a biomaterial is implanted or they may be carried to the surface of the biomaterial by a transient bacteriemia. Once there, their adherence is probably a virulence factor and it may enhance their protection against both antibiotics and natural host defences. The adherence of bacteria in industrial systems protect them from chemical and biocides and antiseptics. Adherence of autochtonous bacteria to ephitelium protects them from surfactants, opsonizing antibodies and phagocytic macrophages ( 12,13,14,15,16,17 ). - Apparently what is needed is antibacterial protection confined to the surface of the implant to prevent bacterial invasion of the implant. Antimicrobial penetration into the surrounding tissues is probably unnecessary.

Tissue Tolerance and Antibacterial Effectiveness of Hydroxylapatite Silver Phosphate Ceramics

The tissue compatibility of the hydroxylapatite silver phosphate ceramics could be demonstrated in the cortex of mongrel dogs. The assessment was done by histomorphometrical methods. The toxicity depends on the content of silver phosphate and the method of manufacture.- In treatment of an experimentally induced osteomyelitis in dogs, hydroxylapatite silver phosphate containing granules had better success than an autologous spongiosa graft or hydroxylapatite granules without the agent.

The nature and role of microbial biofilm in infections associated with prosthetic devices

An understanding of the role of microbial biofilm in infections associated with prosthetic devices is essential for the implementation of successful treatment regimens.

The resistance of maxillofacial reconstruction plates to biofilm formation in vitro

OBJECTIVES/HYPOTHESIS

Bacterial biofilms, bacteria surrounded by a protective glycocalyx, have been demonstrated on bioimplants placed within and outside of the head and neck region. The presence of the biofilm often makes decontamination of an infected implant impossible, requiring removal of the implant. Infections attributable to biofilm formation within the facial skeleton after reconstruction with implants may result in delayed union, fibrous union, malunion, nonunion, and malocclusion. These complications often require removal of the implant and secondary surgery. Although the incidence of infections necessitating implant removal is relatively low, the increased numbers of implants being placed make this a growing problem. Previous work in the authors laboratory has demonstrated a resistance to biofilm formation on different types of pressure-equalizing tubes. The hypothesis evaluated in the study is that such resistance to biofilm formation is due to the inability of bacteria to adhere to the tubes because of the material's smoothness or surface charge.

STUDY DESIGN

A controlled observational study.

METHODS

Scanning electron microscopy was used to evaluate the formation of biofilms in vitro for a common strain of Staphylococcus aureus on four implantable materials. The implantable materials included titanium and polylactide resorbable plates.

RESULTS

Consistent with the authors' prior findings, they were able to produce bacterial biofilm reliably on a silicone pressure equalizing tube but were unable to demonstrate biofilm formation on the titanium or resorbable implants.

CONCLUSION

The absence of biofilm formation on these implants can best be explained by the surface charge or polarity properties of these materials. These findings are consistent with the relatively low incidence of infections among patients receiving these implants in maxillofacial applications.

Safety of instrumentation in patients with spinal infection

OBJECT

Treatment of spine infection remains a challenge for spine surgeons, with the most effective method still being a matter of debate. Most surgeons agree that in early stages of infection, antibiotic treatment should be pursued; under certain circumstances, however, surgery is recommended. The goals of surgery include radical debridement of the infective focus. In some cases, when surgery causes mechanical spinal instability, the question arises whether the risk of recurrent infection outweighs the benefits of spinal instrumentation and stabilization. The authors report their series of cases in which instrumentation was placed in actively infected sites and review the relevant literature.

METHODS

The authors performed a retrospective analysis of all cases of spinal infection that were surgically treated with debridement and placement of instrumentation at their institution between 2000 and 2006. Patient presentation, risk factor, infective organism, surgical indication, level of involvement, type of procedure, and ultimate outcome were reviewed. Improved outcome was based on improvement of initial American Spinal Injury Association Impairment Score.

RESULTS

Forty-seven patients (32 men, 15 women) were treated with instrumented surgery for spinal infection. Their average age at presentation was 54 years (range 37-78 years). Indications for placement of instrumentation included instability, pain after failure of conservative therapy, or both. Patients underwent surgery within an average of 12 days (range 1 day to 5 months) after their presentation to the authors' institution. The average length of hospital stay was 25 days (range 9-78 days). Follow-up averaged 22 months (range 1-80 months). Eight patients died; causes of death included sepsis (4 patients), cardiac arrest (2), and malignancy (2). Only 3 patients were lost to follow-up. Using American Spinal Injury Association scoring as the criterion, the patients' conditions improved in 34 cases and remained the same in 5. Complications included hematoma (2 cases), the need for hardware revision (1), and recurrent infection (2). Hardware replacement was required in 1 of the 2 patients with recurrent infection.

CONCLUSIONS

Instrumentation of the spine is safe and has an important role in stabilization of the infected spine. Despite the presence of active infection, we believe that instrumentation after radical debridement will not increase the risk of recurrent infection. In fact, greater benefit can be achieved through spinal stabilization, which can even promote accelerated healing.

Prophylactic antibiotic usage in patients undergoing inguinal mesh hernioplasty - A clinical study

BACKGROUND

There is ambiguity about the use of antibiotic prophylaxis in inguinal mesh hernioplasty. We have tried to assess the efficacy of antibiotic prophylaxis in this procedure.

MATERIALS AND METHODS

A randomized double blind placebo controlled study was conducted which included 55 patients who underwent an inguinal mesh hernioplasty over a 2 year period. The patients were evaluated for the status of the suture line as well as the presence of wound infection.

RESULTS

Out of 55 patients 29 were randomized to the antibiotic arm and 26 to the placebo group. The groups were well matched for all variables studied excluding wound infections, which occurred at a rate of 10.34% (n = 3) in the antibiotic group and 15.38% (n = 4) in the placebo arm, (p > 0.01).

CONCLUSION

This study did not document any statistically significant difference observed between those who received antibiotics and those receiving placebo in terms of any of the prognostic end points evaluated for Lichtenstein mesh hernioplasty.