Aim. The duration of systemic antibiotic therapy following first-stage surgery is contentious. Our Institution's philosophy is to perform an aggressive debridement, use high concentration targeted antibiotics through cement beads and systemic prophylactic antibiotics alone. In the presence of significant soft tissue infection or microbiological diagnostic uncertainty; systemic antibiotics may be prescribed for 5 days whilst awaiting tissue culture results. The aim of this study was to assess the success of our philosophy in the management of PJI of the hip using our two-stage protocol. Method. A retrospective review of our Institution's prospectively-collected database was performed to identify those patients who were planned to undergo a two-stage hip revision procedure for PJI. All patients had a confirmed diagnosis of PJI as per the major criteria of MSIS 2013, a minimum 5-years follow up and were assessed at the time of review using the MSIS working group outcome-reporting tool (2018). They were then grouped into “successful” or “unsuccessful” (suppressive antibiotics, further revision for infection, death within 1 year). Results. 299 intended two-stage hip revisions in 289 patients (6 repeat ipsilateral two-stage, 4 bilateral two-stage) met our inclusion criteria. 258 (86%) patients proceeded to 2. nd. stage surgery. Median follow up was 10.7 years. 91% success rate was observed for those patients who underwent reimplantation; dropping to 86% when including the patients who did not proceed to second stage surgery. The median duration of post-operative systemic antibiotics following first stage surgery was 5 days (IQR 5–9). No significant difference in outcome was observed in patients who received either; < / = 48 hours (86%; n=70) compared to > 48 hours antibiotics (86%; n=229; p=0.96) or </= 5 days of antibiotics (88%; n=202) compared to > 5 days antibiotics (82%; p=0.38). A significant majority had gram-positive (88%) infection with 30% being polymicrobial. Greater success rates were observed for gram-positive PJI (87%); than for gram-negative PJI (84%) and mixed Gram infection (72%; p=0.098). Conclusion. Aggressive surgical debridement with high concentration, targeted local antibiotic delivery at time of first stage hip surgery, without prolonged systemic antibiotics, provides a high rate of success, responsible antibiotic stewardship and reduced hospital costs

Purpose. To analyze the effectiveness of a vancomycin impregnated calcium sulfate cement bead insertion after debridement (of) an acute-immediate stage infected hip arthroplasty. Materials and Methods. Between 2002 and 2008, 13 patients with documented acute-immediate stage infection of hip arthroplasty were reviewed and followed for at least two years postoperatively(average 4.3 years). The preoperative and postoperative clinical and radiologic findings and blood laboratory work were checked. All cases were performed through retention of the implant and massive debridement and saline irrigation. After that a vancomycin impregnated calcium sulfate cement beads was inserted. Results. After the first operation, the average interval for second operation was 27.7 days (17–37). At the second operation, the erythrocyte sediment rate and C-reactive protein were 150.97 mm/hr (34.6 ∼339.7 mm/hr) and 76.4 mg/L (41∼132 mg/L) respectively. Infectious organism were cultured and isolated. There were 5 cases of Methicillin resistant staphylococcus aureus (MRSA). In addition, results of an antibiotics sensitivity test were 8 cases of Vancomycin, and 5 cases of 3rd generation Cephalosporin. Radiologic results showed 10 cases with stable fixation on last follow-up (femoral stem) and 1 case of hip joint space narrowing, acetabular erosion. Conclusion. Vancomycin impregnated, calcium sulfate, cement bead insertion for an acute immediate infection of hip arthroplasty proved to be a useful method

Aim. To evaluate the ability of different combinations of antibiotic loaded cement to inhibit bacteria growth and biofilm formation. Method. Cement beads were aseptically prepared using Palacos R (plain 40g PMMA cement) or Palacos R+G (40g PMMA cement containing industrially added 0.5g of gentamicin), with or without supplementary antibiotics as follows: Palacos R; Palacos R+G; Palacos R plus 1g / 2g daptomycin; Palacos R+G plus 1g / 2g of daptomycin; Palacos R plus 1g / 2g vancomcyin; and Palacos R+G plus 1g / 2g vancomycin. After production, each antibiotic loaded acrylic cement (ALAC) combination was allocated into two groups (group 1 and 2). The group 2 cement beads were initially eluted in broth at 37. o. C for 72hours then transferred to fresh broth containing a known concentration of bacteria. The group 1 samples were not eluted but directly immerse in culture broth containing bacteria. All samples were thereafter incubated at 37. o. C for 24 hours. After incubation, group 1 samples were visually assessed for bacterial growth, while for the group 2 samples, biofilm formation were quantified using ultrasonication and viable bacteria counting technique. Three proficient biofilm forming Staphylococcus epidermidis bacterial strains (1457, 1585-RA and 5179-R1) were used for all experiments and the bacteria counts were expressed as colony forming units / ml (CFU/ml). Results. In the group 1 samples, all the ALAC combinations were able to inhibit growth of all the three biofilm bacteria strains assessed except the gentamicin only samples in which biofilm growth were observed within 24hours. Meanwhile, in group 2, bacterial growth and biofilm formation by all three bacterial strains were observed on all the ALAC combinations, with the least biofilm formation being on the Palacos R+G plus 2g daptomycin combinations (mean CFU/ml: 1.04E +06) and the greatest on the gentamicin only cement (mean CFU/ml: 2.3E +07). Conclusions. Our study demonstrates that the highest antimicrobial activity of ALAC is seen in the first 24 hours. However, after 72 hours of antibiotic release, fresh bacterial exposure in fresh broth resulted in varying degrees of biofilm colonisation of all ALAC surfaces. Nonetheless, the overall biofilm formation was least on the gentamicin / daptomycin combinations and the results were statistically significant when compared to plain cement (p < 0.05, two tail t-test)

Prosthetic joint infection(PJI) still remains a concern in orthopaedic practice. Antibiotic-loaded acrylic-cement(ALAC) is a proven means of lowering the incidence of PJI. However, increasing antimicrobial resistance has complicated both prophylaxis and treatment, prompting the use of combination antimicrobial therapy, with the addition of vancomycin to gentamicin-containing ALAC commonly used. The new antimicrobial, daptomycin, has better activity than vancomycin and we studied its elution from ALAC in comparison with vancomycin, along with its impact on the co-elution of gentamicin. Cement beads were prepared from PalacosRG containing, 1g/2g daptomycin, 1g/2g vancomycin and without additional antibiotics. Six replicates of each combination were eluted in PBS at 37oC, at timed intervals, for up to 90days, the antibiotic loss was assessed using validated assays. The mean recovery of gentamicin after 90days was 1.1mg with half eluted within the first 6 hours. Recovery was significantly increased by 60% and 40% with addition of 1g&2g of daptomycin(two-tail t-test: p=0.004 and p=0.02), respectively. Although there was a slight increase in gentamicin recovery in vancomycin loaded samples, this was not statistically significant(p>0.05). The significant increases in gentamicin elution from Palacos RG when supplemented with daptomycin, along with a superior activity, may provide a better synergistic effect than PalacosRG supplemented with vancomycin in the management of PJI

Introduction. Antibiotic-loaded acrylic cement (ALAC) is employed in the treatment or prevention of infected total hip arthroplasty (THA). We have administered vancomycin (VCM) as the ALAC for the treatment of THAs with methicillin-resistant Staphylococcus aureus, or for the prevention of THAs with high risks. This study aimed to evaluate the serum concentration of VCM from ALAC in THA or cement beads. Methods. Between December 2013 and February 2014, 16 hips (16 patients) underwent application of the ALAC including VCM at our institution. Two hips were used for the treatment of infection, in the first stage of two-staged revision THAs (i.e., cement beads). Two hips were used for the both treatment and prevention of infection, in one-staged revision THAs. Twelve hips were used for the prevention of infection, in aseptic revision THAs or primary THAs with high risks. Patients were classified into two groups depending on the VCM concentration of ALAC, as follows: high-dose group (2 hips), average 4.4% (3.8–5.0%); low-dose group (14 hips), average 1.6% (1.3–2.5%). The amount of VCM placed as ALAC into the hip was calculated by using the remaining ALAC. The serum concentration of VCM was evaluated at 1 day, 4 days, 7 days, and 28 days after surgery. Statistical analysis was performed by using the t-test, and the differences were considered significant when the p value was <0.05. Results. Average amount of VCM placed as ALAC was 3.5 g (3.1–4.0 g) and 0.9 g (0.3–2.0 g) in the high- and low-dose groups, respectively. The average serum concentration of VCM (μg/mL) was 2.5 and 1.1 on day 1, 2.8 and 1.2 on day 4, 2.3 and 1.1 on day 7, and 1.9 and 1.0 on day 28, in the high- and low-dose groups, respectively. There were significant differences in the high- and low-dose groups on all days. Conclusions. Although the serum concentration of VCM in the high-dose group is significantly increased compared to that in the low-dose group, it is always under the effective blood concentration (5–10 μg/mL) and seem to be clinically safe. Further, we confirmed the continuous effect of ALAC, including VCM, because they were detected at 28 days. However, careful continued follow-up and further evaluation will be required

Introduction. We report our mid-term results and risk factors of a two-stage revision using impaction bone grafting for an infected hip replacement. Methods. A two-stage revision using impacted cancellous allografs and cement was performed in 13 patients (7 total hip replacements, 6 femoral head replacements) with confirmed infection. The mean age of the patients at first stage operation was 63 years (range, 45–84 years). In the first stage, local antibiotics were added to customized cement beads and/or a cement spacer after removal of all components and radical debridement. In the second stage, impaction grafting was done using the X-change system (Exeter). Results. Of the patients, 8 underwent multiple operations to obtain evidence that infection had been overcome in the first stage, and of them, 6 had infection due to methicillin-resistant Staphylococcus aureus (MRSA). The mean duration from first stage operation to second stage revision was 8 months (range, 3–17 months). Only one patient suffered re-infection due to MRSA after second stage revision, which was not the original infecting agent, and the other 12 patients had satisfactory radiological outcomes. The success rate was 92% at the mean follow-up of 4 years (range, 1–10 years) after revision. Conclusion. Allograft bone was shown to be useful for infected hip replacement with a considerable loss of bone stock. We considered that control of MRSA infection is a key factor for successful outcome

Introduction. Infection following traumatic injury of the tibia is challenging, with surgical debridement and prolonged systemic antibiotic therapy well established. Local delivery via cement beads has shown improved outcome, but these often require further surgery to remove. Osteoset-T is a bone-graft substitute composed of calcium sulphate and 4%-Tobramycin, available in pellets that are packed easily into bone defects. Concerns remain regarding the sterile effluent produced as it resorbs, along with the risk of acute kidney injury following systemic absorption. Purpose. We present outcomes of 22 patients treated with Osteoset-T. Methods. Medical notes were reviewed of every case of osteomyelitis of the tibia over a 30-month period, in which Osteoset-T had been used. Excision of infected soft tissue and tibial debridement was performed. Metalwork whenever present removed, before Osteoset-T pellets were packed into any cortical defects or the intra-medullary canal. Further stabilisation (n=9) and soft tissue reconstruction (n=7) was undertaken as required. Intravenous vancomycin and meropenem was administered after sampling. Meropenem discontinued after 3 days if no gram negatives cultured, and vancomycin continued for 1 week. Thereafter targeted antibiotic therapy given for 6 weeks, or ciprofloxacin and rifampicin orally if no growth. Results. Average follow-up was 16 months, with wound complications encountered in 50%. A wound discharge in the early post-operative period was noted in 8 patients (36%) independent of site of Osteoset-T placement, with 6 demonstrating wound healing complications. Whereas only 5 of 14 patients without wound leak developed wound complications, but the difference did not reach significance (p=0.18, Fisher exact test). Union rate and infection eradication was 100%, with only one patient developing a transient acute kidney injury. Conclusion. Despite a high incidence of wound discharge that may promote healing complications, Osteoset-T is an effective adjunct in treatment of chronic tibial osteomyelitis following trauma, with nephrotoxicity concerns not warranted

Aim. Bacterial biofilms play a key role in prosthetic infection (PI) pathogenesis. Establishment of the biofilm phenotype confers the bacteria with significant tolerance to systemic antibiotics and the host immune system meaning thorough debridement and prosthesis removal often remain the only possible course of treatment. Protection of the prosthesis and dead-space management may be achieved through the use of antibiotic loaded cements and beads to release high concentrations of antibiotics at the surgical site. The antibacterial and antibiofilm efficacy of these materials is poorly understood in the context of mixed species models, such as are often encountered clinically. Methods. A P. aeruginosa and S. aureus in vitro co-culture biofilm model was grown using 1/5th BHI supplemented with 20 µM hemin. The ability of beads made from a synthetic calcium sulfate (CaSO4) loaded with vancomycin, tobramycin and vancomycin & tobramycin in combination to prevent biofilm formation and kill established co-culture biofilms were assessed using viable cell counts and confocal scanning laser microscopy (CSLM) over a 7 day time course. To assay for genetic changes to the individual species as a result of their presence together within a biofilm, mutation rates were measured using fluctuation analysis following growth as planktonic and biofilm cultures, alone or in co-culture. Mutants were determined based on their ability to grow on agar plates containing an inhibitory concentration of rifampicin. Mutation rates were calculated using the Ma-Sandri-Sarkar Maximum Likelihood Estimator and 94% confidence intervals compared for significance. Results. Mixed species biofilms displayed differential sensitivity to vancomycin alone and tobramycin alone CaSO4-loaded beads relative to single species biofilms. Preliminary data suggests 10- and 100-fold increase in mutation rates of P. aeruginosa and S. aureus, respectively, when in a co-culture relative to monospecies biofilm which, while further work is needed, may directly or indirectly contribute to the differing antibiotic sensitivities observed. A broad-spectrum intervention of CaSO4-loaded vancomycin & tobramycin beads was able to prevent bacterial colonisation and attenuate P. aeruginosa and S. aureus mixed species biofilm formation for multiple days. Conclusions. Synthetic antibiotic-loaded CS beads, with a broad-spectrum antibiotic combination, have potential to reduce or eliminate mixed species biofilm formation on implant material by providing locally high concentrations over sufficient time periods to aid in the management of PIs. * Stimulan, Biocomposites Ltd

Periprosthetic joint infection (PJI) complicates between 0.5% and 1.2% primary total hip arthroplasties (THAs) and may have devastating consequences. The traditional assessment of patients suffering from PJI has involved the serological study of inflammatory markers and microbiological analysis of samples obtained from the joint space. Treatment has involved debridement and revision arthroplasty performed in either one or two stages.

We present an update on the burden of PJI, strategies for its diagnosis and treatment, the challenge of resistant organisms and the need for definitive evidence to guide the treatment of PJI after THA.

Cite this article: Bone Joint J 2016;98-B(1 Suppl A):27–30.

Between November 1994 and June 1999, 35 patients referred to our Problem Fracture Service with chronic diaphyseal osteomyelitis were treated using a closed double-lumen suction irrigation system after reaming and arthroscopic debridement of the intramedullary canal. This is a modified system based on that of Lautenbach.

Between June and July 2007 the patients were reviewed by postal questionnaire and telephone and from the case notes. At a mean follow-up of 101 months (2 to 150), 26 had no evidence of recurrence and four had died from unrelated causes with no evidence of recurrent infection. One had been lost to follow-up at two months and was therefore excluded. Four had persisting problems with sinus discharge and one had his limb amputated for recurrent metaplastic change.

Our results represent a clearance of infection of 85.3% (29 of 34), with recurrence in 11.8% (4 of 34). They are comparable to the results of the Papineau and Belfast techniques, but with considerably less surgical insult to the patient.