Aim. Debridement, Antibiotics, Irrigation, and implant Retention (DAIR) is a surgical treatment protocol suitable for some patients with fracture related infection (FRI). Clinically relevant pre-clinical models of DAIR are scarce and none have been developed in large animals. Therefore, this project aimed to develop a large animal model for FRI including a DAIR approach and compare outcomes after 2 or 5 weeks of infection. Method. Swiss Alpine sheep (n=8), (2–6 years, 50–80 kg) were included in this study. This study was approved by cantonal Ethical authorities in Chur, Switzerland. A 2 mm osteotomy was created in the tibia and fixed with a 10-hole 5.5 mm steel plate. Subsequently, 2.5 mL of saline solution containing 10. 6. CFU/mL of Staphylococcus aureus MSSA (ATCC 25923) was added over the plate. Sheep were observed for 2 (n=3) or 5 weeks (n=5) until revision surgery, during which visibly infected or necrotic tissues were removed, and the wound flushed with saline. All samples were collected for bacterial quantification. After revision surgery, the sheep were treated systemically for 2 weeks with flucloxacillin and for 4 weeks with rifampicin and cotrimoxazole. After 2 further weeks off antibiotics, the animals were euthanized. Bacteriological culture was performed at the end of the study. Bone cores were isolated from the osteotomy site and processed for Giemsa & Eosin and Brown and Brenn staining. A radiographical examination was performed every second week. Results. Bacteriological evaluation of the retrieved samples during revision surgery showed no significant difference between the 2 vs 5 weeks infection periods in term of total CFU counts. At the end of the study, radiographical examination showed callus formation over the osteotomy site in both groups, although the osteotomy was not completely healed in either group. At euthanasia, the 2 weeks infection group showed a higher soft tissue burden compared to the 5 weeks group, whereby the infection in the 5 weeks group was primarily located in the bone and bone marrow. Conclusions. The large animal model of FRI and DAIR was successfully established. Bacteriological outcomes highlight that the increasing duration of the infection does not change the outcome but the location of the infection from a predominantly soft tissue infection to a deeper bone and intramedullary (IM) channel infection. The debridement of the IM channel could potentially reduce the infection burden by eliminating those bacteria not easily reached by systemic antibiotics, though is not practical using conventional techniques

Irrigation with antiseptic agents, antibiotics, and surfactants are used for treatment and prevention of infections. Despite desirable microbicidal actions, studies have demonstrated cytotoxic effects on host tissue that may impair healing. This study investigated the extent of tissue damage caused by commonly used irrigation solutions in the presence or absence of infection. Air pouches created in 60 balb/c mice were divided into two groups (n=30): infected with Staphylococcus aureus and control. One week later the infected group was subdivided into 5 subgroups (n=6) based on irrigation solutions and by day 0 (immediately) and day7 after irrigation (n=3). Solutions included Saline, Bacitracin, Clorpactin, Irrisept and Bactisure. In infected group wash fluid was collected for quantitative analysis of bacterial growth. At the specified times mice were sacrificed, pouch tissue sent for histology, and sections analyzed for inflammation, necrosis, and edema. Inflammation decreased in infected vs sterile pouches for all solutions except Bacitracin day 0 and for all solutions day 7 with significance in all except Bacitracin (p<0.05). On day 0, necrosis increased in infected vs sterile pouches in Bacitracin (p=0.006), Irrisept (p=0.18), or Bactisure (p=0.07); however, on day 7, necrosis significantly decreased in infected pouches for all solutions (p<0.05) except for Clorpactin (p=0.18). Edema decreased in infected vs sterile pouches on day 0 for all solutions with significance in saline, Irrisept, and Bacitracin (p<0.05). On day 7, infected pouches had decreased edema in saline, Bacitracin, and Bactisure (p<0.05) and increased in Irrisept (p<0.05) and Clorpactin (p=0.069) compared to sterile pouches. Bacterial culture of washouts demonstrated that Clorpactin, Irrisept and Bactisure controlled the infection, whereas saline and Bacitracin showed bacterial multiplication 3.9 × 10^7 CFU/ml and 6.7 × 10^7 CFU/ml respectively. Bacitracin wash showed significantly more bacteria growth compared to Clorpactin (p=0.024), Irrisept (p=0.025) and Bactisure (p=0.025). Tissue damage varied with irrigation solutions and the presence or absence of infection. Presence of bacteria appeared to lead to less tissue inflammation and edema. Tissue necrosis varied over time with different solutions. Surgeons must weigh risks and benefits when selecting solutions and determining when to irrigate

Aim. Irrigation and debridement with an irrigation solution are essential components of the surgical management of acute and chronic periprosthetic joint infection (PJI). Nevertheless, there is a lack of agreement regarding the most effective solution to use. The aim of the study was to perform a systematic review and meta-analysis of the current literature concerning the efficacy of different irrigation solutions over bacterial biofilm. Method. This study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis extension for Network meta-analysis (PRISMA-NMA) checklist for systematic reviews and meta-analyses. A comprehensive literature search of PubMed, Cochrane Library, Web of Science and Scopus databases from inception to September 1, 2023. We combined terms related to PJI, biofilm and irrigation solutions studied in vitro. We performed a network meta-analysis to analyze which irrigation solution achieved a higher reduction of colony forming units (CFU) after specific exposure times, always with a maximum of five minutes, replicating intraoperative conditions. Effect-size was summarized with logarithmic response ratio (logRR) and 95% confidence intervals (95% CI). The rank probability for each treatment was calculated using the p-scores. Results. We screened 233 potential sources. Following deduplication, screening and full-text review, four studies with ten irrigation solutions for different duration of exposures were included, always less than five minutes, replicating intraoperative conditions. Solutions were studied over mature biofilms of most frequent bacteria grown over metal, bone cement or polyethylene surfaces. The highest effect was achieved with povidone iodine 10% during 5 minutes (logRR: −12.02; 95% CI: −14.04, −9.99). The best ranked solutions were povidone iodine 10% during five, three and one minute (respective p-scores: 0.977, 0.932, 0.887) and its combination with hydrogen peroxide for 3 minutes (p-score: 0.836). Povidone iodine 0.3% acting for 5 minutes completed the top 5 best ranked solutions in this study (p-score: 0.761). We assumed that there were no inconsistencies in our network because after examining both scenarios, with and without inconsistencies, the results were not significantly different. Conclusions. Our results show that 10% povidone-iodine is the best antiseptic solution when studied in vitro in the context of prosthetic joint infection. However, the included studies did not evaluate the possible cytotoxic effects of these solutions. This should also be taken into account before choosing the most appropriate antiseptic solution

We present the first systematic review conducted by the UK Defence Medical Services in conjunction with the Cochrane Collaboration. Irrigation fluids are used to remove contamination during the surgical treatment of traumatic wounds in order to prevent infection. This review aims to determine whether there is evidence that one wound irrigation fluid is superior to another at reducing infection. A pre-published methodology was used and two reviewers independently assessed the search results. The search produced 917 studies, of which three met the inclusion criteria. All were studies in open fractures, incorporating a total of 2,903 patients. Each RCT involved a distinct comparison, precluding meta-analysis: i) sterile saline vs. distilled/boiled water; ii) antibiotic solution vs. soap solution; iii) saline vs. soap solution. The odds ratios of infection following irrigation with various fluids was as follows: i) saline vs. distilled or boiled water 0.25 (95%CI 0.08–0.73); ii) antibiotic solution vs. soap 1.42 (95%CI 0.82–2.46); iii) saline vs. soap solution 1.00 (95%CI 0.80–1.26). These results suggest that neither soap nor antibiotic solution is superior to saline and that saline is inferior to distilled or boiled water

Historical perspective: Irrigation and debridement (I&D) with modular exchange has historically been the recommended treatment for acute post-operative periprosthetic joint infection (PJI), and acute hematogenous PJI. The theory supporting this practice was that because the bacterial glycocalyx had not yet formed by these early time points, by simply debriding the intra-articular bacterial load and exchanging the modular parts, one could potentially eradicate the infection, retain the prior components, and minimise morbidity to the patient. More recently, literature is coming out suggesting that this may not necessarily be the case. The vast majority of published research on the outcomes following I&D for treatment of PJI has focused on either cohorts of total knee arthroplasty patients or combined cohorts of total hip and knee patients. For this reason, it is difficult to tease out the differential success rate of periprosthetic hip vs. knee infections. Sherrell et al. performed a systematic review of the existing literature and created a table detailing the failure rates for various published articles on I&D for periprosthetic TKA infection. Since it is the glycocalyx that has been thought to be the reason for treatment failure of many cases of PJI treated with I&D, many authors have implicated staphylococcal species as a predictor of a negative outcome with failure rates ranging from 30–35%. Methicillin resistant organisms have been shown to be particularly difficult to eradicate with an isolated I&D, with a 72–84% failure rate at 2 year follow-up. Interestingly, a recent study by Odum et al. suggests that neither the infecting microbe, nor the antibiotic resistance profile of the organism, as has been classically thought, actually predicts success of I&D. Previous reports have indicated that the ability of I&D to control infection is related to the duration of symptoms and its timing relative to the index surgery. However, more recent literature is coming out to support the contrary. Koyonos et al. reviewed the outcomes of a series of 138 cases of PJI treated with I&D based on acuity of infection and concluded that an I&D has a limited role in controlling PJI regardless of acuity. Intuitively, the physical health of the host/patient should influence the success of I&D for treatment of PJI. Several authors have shown that an immunocompromised state is a predictor of treatment failure. Furthermore, Azzam et al. reported that patients with a higher American Society of Anesthesia (ASA) score, a proxy of severity of medical comorbidities, had a significantly higher failure rate. Although potentially appealing due to relative ease of execution and minimal surgical morbidity, the ability to successfully eradicate infection with an arthroscopic procedure may be compromised. Given the inability to perform a radical surgical debridement, nor exchange modular components, arthroscopic debridement should be used with extreme reservation in any case of PJI, regardless of the host, nature of the infecting organism, or acuity of infection. I&D as a conservative, less morbid alternative to two-stage exchange - There is a growing body of literature to suggest that an I&D with modular component exchange may not be the benign, less morbid alternative to the ‘gold standard’ two-stage exchange arthroplasty. In fact, Fehring et al. has reported that the success of a two-stage antibiotic spacer exchange arthroplasty may be compromised by an initial I&D. They found that patients who were initially treated with an I&D only had a 66% chance of eradicating infection following a two-stage exchange arthroplasty, in contrast to historical reports of 80–90% success

There is no doubt that peri-prosthetic joint infection (PJI) is one the most terrible complications of joint arthroplasty. There has been a surge of interest in PJI in recent years as this problem moves to be the last frontier in joint arthroplasty. There are a number of strategies employed for prevention of PJI. Irrigation of the surgical site with various irrigation solutions is one such strategy as it helps reduce bioburden in the wound and reduce the potential for subsequent infection. Although the irrigation solution may work by dilution phenomenon alone, some believe that bactericidal or bacteriostatic agents may be added to the irrigation solution to increase its efficacy. Addition of antibiotics (Abx) to the irrigation solution stems from the same reasoning. There are a number of serious issues related to the addition of Abx to the irrigation solution or in fact, for pouring into the wound (like the vancomycin powder). Efficacy: There are no randomised prospective studies to demonstrate that addition of Abx to the irrigation solution improves “kill”. To do such a study would be logistically challenging. Basic science studies and other clinical studies with a small number of patients have failed to prove the efficacy of Abx in the irrigation solution. In fact, I would argue that the use of agents like dilute betadine is much more likely to be effective in reduction of bioburden without having many of the issues related to the use of Abx in irrigation solution. Emergence of Resistance: Some may argue what would one lose by adding Abx to the wound or the irrigation solution. The modern society is facing an emerging catastrophe. Antimicrobial Resistance (AMR), if it persists, will kill more people than cancer by the year 2050. Annually 1000s of patients die of ESKAPE or AMR related issues. A recent task force convened by the British government produced a report about AMR which is sobering. The main finding of the task force was that continued liberal use of Abx will lead to further escalation of the AMR crisis that threatens the modern society. The guidelines by the CDC, that are about to be published, will discourage clinicians from pouring Abx into wounds and asks clinicians to exercise Abx stewardship. Expense: There are costs associated with the use of Abx in any circumstance including their addition to irrigation solution. With over 1 million joint arthroplasties being done in the US alone, this cost can be substantial. Hypersensitivity reactions: The use of Abx is not without problems. There have been a few fatalities associated with the use of Abx in patients with recognised and possibly unrecognised hypersensitivity to antibiotics

This study documents the use of bone graft harvested by the RIA system and used in treating segmental bone loss in the femur and tibia following trauma. Eight patients with segmental defects of the tibia or femur were enrolled in the study. The segmental defects were optimized for bone grafting by repeated debridements and muscle flap coverage as required. Graft was harvested from the ipsilateral femur via a percutaneous technique. Volumes of bone graft were recorded and then placed to the defect site during the same surgical procedure. The average age of the patients was twenty-nine years (sixteen to forty-one years). In the five tibiae and three femora there were four grade IIIA, three grade IIIB and One grade IIIC injuries. Muscle flap coverage was required in four patients. The average size of defect was 7 cm (1–14.5 cm). The RIA grafting was performed at an average of three months (2.5 – 5 months) post injury. The average bone graft volume obtained was 73cc(45–90 cc). The average hemoglobin drop was 4.4g/dl(2.3 – 8.0 g/dl) and the average hematocrit drop was 12.3%(6–21%). One patient required transfusion. Donor site complications were limited to one post-operative bleed. Defect site complications included one wound dehiscence and two infections. Radiographic union of the defects was achieved at an average time of four months (two to twelve months). Grafting of large segmental defects using RIA bone graft has resulted in union at an average of four months. This technique represents an alternative to bone transport for treatment of segmental defects. Reamed Irrigation Aspirator (RIA) allows access to large volumes of bone graft from the femur through percutaneous technique. The grafting technique was utilized to obtain graft for eight segmental defects in the tibia and femur. These healed at an average of four months

Aim

This study aims to evaluate the effectiveness of a pre-formulated irrigation solution¹ (containing ethanol, acetic acid, sodium acetate, benzalkonium chloride, and sterile water) compared to saline solution in managing acute periprosthetic joint infections (A-PJI) during Debridement, Antibiotic, and Implant Retention (DAIR) surgeries. The primary objective is to assess the healing rate using this solution¹ versus saline in A-PJI patients, with “cure” defined by a set of criteria including no recurrence, wound issues, or need for ongoing suppressive antibiotics after 1 year. Principio del formularioFinal del formulario

Introduction

Debridement, Antibiotics and Implant Retention (DAIR) remains the norm for the treatment of acute periprosthetic joint infection (PJI) despite less than optimal success rates. Intraosseous (IO) administration of vancomycin has been shown to have significantly increased local bone and tissue concentrations compared to systemic antibiotics, with lower systemic antibiotic levels compared to intravenous. The purpose of this study was to evaluate if the addition of IO regional antibiotics to our protocol at the time of DAIR would improve outcomes.

Aim

The efficacy of various irrigation solutions in removing microbial contamination of a surgical wound and reducing the rate of subsequent surgical site infection (SSI), has been demonstrated extensively. However, it is not known if irrigation solutions have any activity against established biofilm. This issue is pertinent as successful management of patients with periprosthetic joint infection (PJI) includes the ability to remove biofilm established on the surface of implants and necrotic tissues. The purpose of this study was to evaluate the efficacy of various irrigation solutions in eradicating established biofilm, as opposed to planktonic bacteria, in a validated in vitro model.

Introduction

The use of irrigation solution during surgical procedures is a common and effective practice in reduction of bioburden and the risk of subsequent infection. The optimal irrigation solution to accomplish this feat remains unknown. Many surgeons commonly add topical antibiotics to irrigation solutions assuming this has topical effect and eliminates bacteria. The latter reasoning has never been proven. In fact a few prior studies suggest addition of antibiotics to irrigation solution confers no added benefit. Furthermore, this practice adds to cost, has the potential for anaphylactic reactions, and may also contribute to the emergence of antimicrobial resistance. We therefore sought to compare the antimicrobial efficacy and cytotoxicity of irrigation solution containing polymyxin-bacitracin versus other commonly used irrigation solutions.

Prevention and treatment of total joint infection is closely related to biofilm formation and concentration of antibiotics achieved in the area around the implants. Most total joint infections are caused by bacteria that enter the wound at the time of the operation. These bacteria can attach to surfaces and rapidly form biofilm that is highly resistant to antibiotics. Prophylactic antibiotics given intravenously achieve concentration of local antibiotics in the knee in response to intravenous antibiotics about 1/3 of that achieved in the serum, and the level is transient. This may be enough to treat the planktonic form of the bacteria, but far from enough to treat the biofilm. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery. Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and cost analysis shows remarkable monetary benefit to this effect.

Infected total joints benefit especially from direct application of antibiotics to the local area. The safety and efficacy of this protocol was evaluated in patients undergoing primary or revision TKA by measuring joint and serum levels of vancomycin following IV administration (as a prophylactic) and IA administration (as a treatment for infected TKA), and comparing the levels with each method. Therapeutic levels of vancomycin were present in the knee following IV or IA administration, but much higher levels were possible with IA administration (average of 6.8 and 9,242µg/mL, respectively). Vancomycin achieved therapeutic levels in the synovial fluid of the knee with IV administration, but clearance from the knee was rapid, suggesting that the synovial fluid concentration may be sub-therapeutic for hours before the next IV dose is given. In contrast, IA delivery of vancomycin resulted in peak levels that were thousands of times higher, and trough levels remained therapeutic for 24 hours in both the joint space and in the serum (minimum trough levels of 8.4 and 4.2µg/mL, respectively). The elimination constant (half-life) of IA-administered vancomycin was 3.1 hours.

Directly infusing antibiotics into the infected area maintains a high local concentration level while minimizing systemic toxicity. This method avoids the use of antibiotic-loaded cement and the potential for growth of antibiotic-resistant strains of bacteria. These findings support single-stage revision in cases treated with cementless revision and IA antibiotics.

Preventing and treating infection in orthopaedic implant surgery requires achieving concentrations that are above the minimal biofilm eradication concentration. This can be achieved only with direct application.

Introduction

Debridement, antibiotics, and implant retention (DAIR) for acute prosthetic hip infection is a popular low morbidity option despite less than optimal success rates. We theorized that the delay between DAIR and explantation in failed cases may complicate eradication due to biofilm maturation and entrenchment of bacteria in periprosthetic bone. We ask, what are the results of two-stage reimplantation after a failed DAIR versus an initial two-stage procedure?

Prevention and treatment of total joint infection is closely related to biofilm formation and concentration of antibiotics achieved in the area around the implants. Most total joint infections are caused by bacteria that enter the wound at the time of the operation. These bacteria can attach to surfaces and rapidly form biofilm that is highly resistant to antibiotics. Prophylactic antibiotics given intravenously achieve concentration of local antibiotics in the knee in response to intravenous antibiotics about 1/3 of that achieved in the serum, and the level is transient. This may be enough to treat the planktonic form of the bacteria, but far from enough to treat the biofilm. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery. Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and cost analysis shows remarkable monetary benefit to this effect.

Infected total joints benefit especially from direct application of antibiotics to the local area. The safety and efficacy of this protocol was evaluated in patients undergoing primary or revision TKA by measuring joint and serum levels of vancomycin following IV administration (as a prophylactic) and IA administration (as a treatment for infected TKA), and comparing the levels with each method. Therapeutic levels of vancomycin were present in the knee following IV or IA administration, but much higher levels were possible with IA administration (avg. of 6.8 and 9,242 µg/mL). Vancomycin achieved therapeutic levels in the synovial fluid of the knee with IV administration, but clearance from the knee was rapid, suggesting that the synovial fluid concentration may be sub-therapeutic for hours before the next IV dose is given. In contrast, IA delivery of vancomycin resulted in peak levels that were thousands of times higher, and trough levels remained therapeutic for 24 hours in both the joint space and in the serum (minimum trough levels of 8.4 and 4.2 µg/mL, respectively). The elimination constant (half-life) of IA-administered vancomycin was 3.1 hours.

Directly infusing antibiotics into the infected area maintains a high local concentration level while minimizing systemic toxicity. This method avoids the use of antibiotic-loaded cement and the potential for growth of antibiotic-resistant strains of bacteria. These findings support single-stage revision in cases treated with cementless revision and IA antibiotics.

Preventing and treating infection in orthopaedic implant surgery requires achieving concentrations that are above the minimal biofilm eradication concentration. This can be achieved only with direct application.

Infection is still a major problem in implant surgery. Most infections are caused by bacteria that enter the wound at the time of the operation. Although prophylactic antibiotics given intravenously have been shown to be effective if given during the correct time frame, the concentration of local antibiotics in the knee in response to intravenous antibiotics is about 1/3 that achieved in the serum, and the level is transient. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery.

Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and cost analysis shows a remarkable monetary benefit to this effect.

Local antibiotic irrigation during implant surgery is inexpensive, easy, and effective.

Despite long-standing dogma, a clear relationship between the timing of surgical irrigation and the development of subsequent deep infection has not been established in the literature. Traditionally, irrigation of an open fracture has been recommended within six-hours of injury based on animal studies from the 1970s, however the clinical basis for this remains unclear. Using data from a multi-centre randomized controlled trial of 2,447 open fracture patients, the primary objective of this secondary analysis is to determine if a relationship exists between timing of wound irrigation (within six hours of injury versus beyond six hours) and subsequent reoperation rate for infection or healing complications within one year for patients with open extremity fractures requiring surgical treatment.

To adjust for the influence of patient and injury characteristics on the timing of irrigation, a propensity score was developed from the data set. Propensity-adjusted regression allowed for a matched cohort analysis within the study population to determine if early irrigation put patients independently at risk for reoperation, while controlling for confounding factors. Results were reported as odds ratios (ORs), 95% Confidence Intervals (CIs), and p-values. All analyses were conducted using STATA 14 (StataCorp LP, College Station, TX, USA).

Two thousand, two hundred eighty-six of 2,447 patients randomized to the trial from 41 orthopaedic trauma centers across five countries had complete data regarding time to irrigation. Prior to matching, the patients managed with early irrigation had a higher proportion requiring reoperation for infection or healing complications (17% versus 12.8%, p=0.02), however this does not account for selection bias of more severe injuries preferentially being treated earlier. After the propensity score-matching algorithm was applied, there were 373 matched pairs of patients available for comparison. In the matched cohort, reoperation rates did not differ between early and late groups (16.1% vs 16.6%, p=0.84). When accounting for propensity matching in a logistic regression analysis, early irrigation was not associated with reoperation (OR 0.93, 95% CI 0.62 to 1.40, p=0.73).

When accounting for other variables, late irrigation does not independently increase risk of reoperation.

Infection is still a major problem in implant surgery. Most infections are caused by bacteria that enter the wound at the time of the operation. Although prophylactic antibiotics given intravenously have been shown to be effective if given during the correct time frame, the concentration of local antibiotics in the knee in response to intravenous antibiotics is about 1/3 that achieved in the serum, and the level is transient. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery.

Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and costs analysis shows a remarkable monetary benefit to this effect.

Local antibiotic irrigation during implant surgery is inexpensive, easy, and effective.

Infection is still a major problem in implant surgery. Most infections are caused by bacteria that enter the wound at the time of the operation. Although prophylactic antibiotics given intravenously have been shown to be effective if given during the correct time frame, the concentration of local antibiotics in the knee in response to intravenous antibiotics is about 1/3 that achieved in the serum, and the level is transient. The concentration of antibiotics in the joint fluid achieved with antibiotics applied locally during surgery is 1000 times higher, and can be maintained throughout the procedure. High concentration persists in drainage fluid for 24 hours after surgery.

Studies done with use of local antibiotics in spinal implant surgery indicate a major reduction in the rate of infection, and costs analysis shows a remarkable monetary benefit to this effect.

Local antibiotic irrigation during implant surgery is inexpensive, easy, and effective.

Polymethylmethacrylate (PMMA) Acrylic Bone Cement is a polymer used to anchor the prosthesis during Joint Replacement Surgery. Arthroplasty with Bone Cement is associated with late loosening, compromising prosthetic stability leading to Revision arthroplasty. Different irrigating solutions such as Hydrogen Peroxide or Saline are used during arthroplasty. The aim of the study was to analyse the effects of Hydrogen Peroxide on the mechanical properties of Bone Cement.

Materials and Methods: Cement was mixed as per standard methods used in theatre, in a vacuum and at a temp of 18 degrees centigrade. Once the cement was mixed it was then placed in conical moulds and the exposed surface was either exposed to saline or Hydrogen Peroxide solution (6% from a standard theatre preparation). We studied the effect of Hydrogen Peroxide on Dough time, Curing time, Surface Analysis and Hardness of PMMA. Dough time was performed with latex examination gloves. Curing time was measured at 15 seconds intervals using a Vickers hardness transistor. Cement hardness was assessed using the same machine. Surface analysis was performed by preparing the samples using a grit rotaforce machine. Palacos Bone Cement was used and tests were conducted according to ASTM F-451 and ISO 5833 standards.

Results: The samples exposed to hydrogen peroxide showed an increase in the dough time in comparison to the controls from 3.5 minutes to 5 minutes. Curing time showed a difference of 13.5 minutes for the controls as opposed to 17 minutes for the HP contaminated samples. Surface hardness reduced from a mean of 17.5hv to 14.3hv after exposure to hydrogen peroxide (p< 0.05). There was increased staining of the Hydrogen Peroxide sample, with surface irregularities, and an associated increase in surface porosity. Surface porosity increased from 120um (SD 11.2) to 180um (SD 8.7) (p< 0.05).

Conclusion: We have shown that the use of hydrogen peroxide contamination of bone cement interferes with the biomechanical properties of the cement, leading to an overall reduction in strength and hardness of the cement. This may lead to an associated reduction in the strength of the bone cement interface and precipitate early micro-motion and loosening of the prosthesis.

Debridement of an infected total joint arthroplasty with retention of mechanically stable components is often performed for acute cases of periprosthetic infection (PPI). However, the reported success of such a procedure to fully eradicate infection has varied widely. The objective of this study was to elucidate the efficacy of debridement in both infected THA and TKA and attempt to identify risk factors responsible for failure.

During the years 2000–2005, 71 TKA and 69 THA underwent irrigation and debridement for acute PPI (< 4 weeks). All patients were followed up prospectively for at least two years. Detailed data including demographics, comorbidities, surgical history, and medication intake was collected. Intraoperative data, organism profile, and complications were also documented. Failure was defined as patient requiring additional surgical procedure for control of infection or loosening.

Of the 140 patients, 24% required repeat irrigation and debridement for postoperative drainage, hema-toma formation, or systemic symptoms. One third of these revision debridement patients underwent multiple consecutive debridements. Two-stage resection arthroplasty was required in 65 patients (46%) of the entire cohort. Fifty-eight percent of the patients with resection required revision of their cement spacer block due to continuous drainage and systemic symptoms indicative of persistent infection. We noted a total of 86 failures (61%) that required either an additional debridement or resection arthroplasty after the first debridement procedure. The failure rates of THA (62%) and TKA (55%) individually were similar (p=0.253).

Although the concept of conservative management of PPI with debridement and retention of components is an attractive alternative to resection arthroplasty, we have found that 60% of patients undergoing this procedure will inevitably undergo two-stage arthroplasty. Furthermore, more than half of the patients that required resection arthroplasty developed infection of their spacer that entailed revision of the cement block. Therefore, we can conclude that this procedure has a high failure rate and should be implemented in only a select group of patients.