Infection following total hip or knee arthroplasty is a serious complication. We noted an increase in post-operative infection in cases carried out in a temporary operating theatre. We therefore compared those cases performed in standard and temporary operating theatres and examined the deep periprosthetic infection rates. A total of 1233 primary hip and knee arthroplasties were performed between August 2012 and June 2013. 44% were performed in temporary theatres. The two groups were matched for age, sex, BMI and ASA grade. The deep infection rate for standard operating theatres was 0/684 (0%); for temporary theatres it was 8/539 (1.5%); p=0.001. Use of a temporary operating theatre for primary hip and knee arthroplasty was associated with an unacceptable increase in deep infection. We do not advocate the use of these theatres for primary joint arthroplasty

Deep infection is a devastating complication of total knee arthroplasty (TKA). This study aimed to determine if there was a relationship between surgeon volume and the incidence of revision for infection after primary TKA.

Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 1 September 1999 to 31 December 2020 for primary TKA for osteoarthritis that were revised for infection. Surgeon volume was defined by the number of primary TKA procedures performed by the surgeon in the year the primary TKA was performed and grouped as <25, 25-49, 50-74, 75-99, >100 primary TKA procedures per year. Kaplan Meir estimates for cumulative percent revision (CPR) and Cox Proportional Hazard Ratios were performed to compare rates of revision for infection by surgeon volume, with sub-analyses for patella and polyethylene use, age <65 years and male gender.

5295 of 602,919 primary TKA for osteoarthritis were revised for infection. High volume surgeons (>100 TKA/year) had a significantly lower rate of revision for infection with a CPR at 1 and 17 years of 0.4% (95% CI 0.3, 0.4) and 1.5% (95% CI 1.2, 2.0), respectively, compared with 0.6% (95% CI 0.5, 0.7) and 2.1% (95% CI 1.8, 2.3), respectively, for low volume surgeons (<25 TKR/year). Differences between the high-volume group and the remaining groups remained when sub-analysis for age, gender, ASA, BMI, patella resurfacing and the use of cross-linked polyethylene (XLPE).

High volume surgeons have lower rates of revision for infection in primary TKA.

Endoprosthetic replacement following oncological conditions has shown to be at higher risk of sceptical complications due to the use of implants of unusual size, major soft tissue loss and immunsupression. 373 patients have been treated at our institution for malignant tumours of the bone or soft tissue around the knee with a modular tumour-prostheses of the knee joint since their availability from 1978. Infection or septic complications were identified in 78 patients (20.9%). In 15 cases of superficial wound healing disturbances with a fistula simple excision and revision of the wound was performed. In 48 cases of deep periprosthetic infections patients underwent one-stage revision with explantation of the total prosthetic material except femoral and tibial stems, extensive debridement of the wound and replantation of the disinfected prostheses throughout one operation. In 8 patients two-stage revision of the prostheses was performed, using an antibiotic impregnated cement spacer and Steinmann nails. In 5 patients amputation of the affected limb was indicated, whereas 2 patients could be treated conservatively. Out of the patients treated by one-stage revision 16 developed recurrent infection and had to undergo consecutive surgery. After two-stage surgery 4 patients showed signs of septic recurrence. According to our results deep periprosthetic infection of tumour-prostheses primarily can be treated by one-stage revision, in recurrent infections, however, two-stage revision should be performed. We additionally suggest the use of local or pedicled muscle flaps to obtain better soft tissue coverage of the prostheses after infection

Deep periprosthetic infection after hip or knee arthroplasty is a disconcerting problem for patient and surgeon alike. The diagnosis of infection is sometimes obvious but frequently requires that the surgeon maintain a substantial index of suspicion for infection as the cause of pain or poor outcome after any joint arthroplasty. While surgical debridement with component retention is appropriate in a subgroup of patients with an acute periprosthetic infection most delayed and chronic infections are best treated with component resection. The pre-eminent role of two-stage exchange as the definitive treatment was established over 30 years ago. Two-stage exchange remains the gold-standard in treatment with an established track record from multiple centers and with multiple different types of infecting organisms. Some of the historical problems with two-stage exchange, such as limited mobility during the interval stage, have been mitigated with the development of effective articulating spacer techniques. Further, the emergence of drug resistant bacteria and the possibility of fungal infection make two-stage exchange the best choice for the majority of patients with deep periprosthetic joint infection in 2015

Persistent wound drainage after total joint arthroplasty (TJA) has been associated with a higher incidence of superficial and deep periprosthetic infection but the predictors for prolonged drainage and its outcome have not been thoroughly studied. A consecutive series of 7,153 TJA cases performed between 2000 and 2006 at our institute, were recruited into this study. There were 301 cases (4.2%) of persistent wound drainage, defined as discharge from the wound for > 48 hours. The cases were matched in a 2:1 ratio for type of surgery, joint replaced, and date of surgery. This study identified higher BMI (p< 0.005), malnutrition as defined by serum albumin< 3.4g/dl (p< 0.04), longer operative time (p< 0.01), and higher medical comorbidities, in particular diabetes (p< 0.001) as important risk factors for persistent wound drainage. In addition, patients in the drainage group were more likely to have a peak INR of > 1.5 (p< 0.001) during their hospital stay. Patients with wound drainage had a significantly lower hemoglobin postoperatively (p< 0.01) that necessitated greater number of postoperative allogenic transfusions (p=0.004). The hospital length of stay for the drainage group was also significantly higher (p< 0.005). One of the major risk factors for development of deep infection was prolonged drainage (> 7 days). In the deep hematoma and periprosthetic subgroups, the mean of delay in treatment was 6 days in those with retention of the prosthesis and successful outcome, and 9.5 days for those with failure of incision and drainage leading to resection arthroplasty (p= 0.03). 72% of the patient were successfully treated by oral or intravenous antibiotics. 27% required at least one re-operation for deep hematoma and 13% developed deep periprosthetic infection, resulting in 6% rate of resection arthroplasty. 1.5% of those with drainage remained in girdlestone status. This study suggests early surgery for persistent drainage and avoidance of aggressive anticoagulation

Aim: To determine the cost of medical treatment of infection following total joint replacement (TJR) of the hip or knee. With this information, and obtaining the current costs of antibiotics, antibiotic loaded cement and laminar flow theatres, we aimed to calculate the relative cost- benefit of these prophylactic strategies to prevent infection. Method: Fifty two patients who were admitted to The Canberra Hospital (TCH) for treatment of infection at following total joint arthroplasty between January 1996 and January 2001. A detailed cost analysis of treatment costs following infection was performed. All ward, theatre, prosthesis, investigation, pharmaceutical, allied health and medical costs were collated to produce a total cost of treatment. Current costs of prophylactic antibiotics, antibiotic cement and laminar flow theatres were obtained from suppliers. Costs were calculated for different combinations of prophylactic measures using the rates of deep periprosthetic infection reported through the Swedish Arthroplasty Registry. Results: There were 41 deep infections and 13 superficial. The average cost for the 54 patients for the in hospital treatment of infection was $41,215. The cost of treating a superficial infection with antibiotics alone averaged $17,663. The average cost of a two stage revision procedure for deep periprosthetic infection was $79,623. Assuming a hospital volume of 150 cases per year, the use of prophylactic intravenous antibiotics, the use of laminar flow and the combined use of antibiotics and laminar flow were significantly cost effective. The addition of antibiotic loaded cement was marginally cost ineffective in combination with either or both of intravenous antibiotics or laminar flow. Conclusion: The in hospital costs for the treatment of infection after TJR in the Australian setting have been addressed for the first time. Past studies have underestimated the cost of treatment. With this information, we have shown that the combinations of laminar flow and intravenous antibiotic for prophylaxis against infection in TJR are justified on a purely financial cost benefit basis

Aim. This study aimed to identify risk factors for development of deep periprosthetic joint infection (PJI) in patients following surgical treatment of neck of femur fracture. Method. This study identified a consecutive series of 2,822 (2,052 female, 73%) patients who underwent either hemiarthroplasty (n=1,825, 65%) or fixation (DHS) (n=997, 35%) for fractured neck of femur performed between January 2009 and June 2015 at our institution. Full patient demographics, co-morbidity and peri-operative complication data were determined. The majority of patients were either ASA 2 (n=663, 23%) or ASA 3 (n=1,521, 54%), mean age = 81.3 years (SD 10.3). All patients were followed up post-operatively by a dedicated surgical site infection (SSI) monitoring team in order to identify patients who developed a PJI within 1 year. A stepwise multivariable logistic regression model was used to identify patient and surgical factors associated with increased risk of infection. Predictors with a p-value of <0.20 in the univariate analysis were included in the multivariate analysis. Results. Thirty-nine (39) cases of deep periprosthetic infection were identified (hemiarthroplasty n=35, DHS n=4) representing an overall deep infection rate of 1.4% (hemiarthroplasty 1.9%, DHS 0.4%). The most common infecting pathogen was a pure growth of coagulase negative Staphylococcus (n=9, 23%) followed by a pure growth of Staphylococcus aureus (n=7, 18%). An increased risk of PJI was observed in patients who underwent hemiarthroplasty compared to those treated by fixation (odds ratio (OR) 6.50, 95%CI 2.26 – 18.7, p=0.001). Of patient factors, only blood transfusion within 30 days (OR 3.51, 95%CI 1.72 – 7.13, p=0.001) and the presence or development of pressure sores on or during admission (OR 2.99, 95%CI 1.24 – 7.19, p=0.015) were significantly associated with an increased risk of development of PJI. Use of high-dose dual antibiotic cement (gentamicin and clindamycin) was associated with a two-fold reduction in the risk of PJI (OR 0.39, 95%CI 0.20 – 0.76, p=0.005) vs standard dose gentamicin antibiotic cement. Conclusions. This study found: 1) a deep infection rate similar to that reported earlier from large number studies from the UK, 2) a six-fold higher deep infection rate in hemiarthroplasties, compared to internal fixations, and 3) a three-fold higher infection rate in patients who suffer concomitant pressure sores or receive a blood transfusion up to 30 days post-operatively

Propionibacteria are organisms of low virulence, although they do cause deep periprosthetic infections. The aim of this study was to show that Propionibacteria do not always cause a significant rise in ESR and CRP. Between May 2001 and May 2004, we identified 77 patients with prosthetic joint replacements colonised with Propionibacteria, 47 males and 30 females. There were 47 hip joint replacements, 27 knee joint replacements, 2 endoprosthetic replacements of the femur and 1 shoulder joint replacement. We retrieved successfully the medical records of 66 patients in order to identify the number of patients treated for an infected prosthetic joint arthroplasty. The pre-operative values of ESR and CRP were recorded. For the purposes of this study, an ESR rate of 30mm/hr or higher and a CRP level of 10mg/lt or higher were considered to be suggestive of infection and were deemed a positive result. All of the 77 patients had both ESR and CRP measured pre-operatively. In only 16 (21%) both ESR and CRP were higher than 30mm/hr and 10mg/l respectively. In 33 patients (43%) with prosthetic joint replacements colonised with Propionibacteria, the pre-operative values of ESR and CRP were normal. 23 patients were treated for an infected prosthetic joint arthroplasty. In 7 (30%) of those patients both ESR and CRP were normal. This suggests that normal pre-operative values of ESR and CRP in suspected failed prosthetic joint replacements might not exclude infection, if the causative organism is of low virulence such as Propionibacteria

Introduction and purpose: Two-stage reimplantation of a hip replacement is the treatment of choice for deep periprosthetic infections. The purpose of this study is to analyse the survival of the femoral component in two-stage hip replacement reimplantations and compare the results of cemented and cementless components. Materials and methods: Between 1988 and 1998 our hospital carried out 169 two-stage reimplantations for treatment of first episodes of deep infection. The femoral component was cemented in 121 cases and cementless in 48. All patients were followed up clinically and radiologically for at least five years. Results: The two-stage revision was associated with a significant clinical improvement. The reinfection rate was 9% (16/169), of which 11 patients underwent revision surgery and five received chronic suppressive antibiotic treatment. Eight patients required revision due to aseptic loosening and two for periprosthetic fracture. With the numbers available, fixation with or without cement showed no significant differences. Conclusions: The two-stage revision of an infected hip prosthesis resolved the infection in 91% of the cases. An additional 5% required revision due to aseptic loosening. The surgical outcomes seem to be independent of the femoral component fixation (cemented or cementless)

An analysis on prospective data collected on our hip database was carried out on all patients undergoing primary cemented unilateral total hip arthroplasty in the last 5 years comparing the short term outcomes between diabetics and non-diabetics. There were 1220 non-diabetics and 77 diabetics identified from the database with at least 3 years follow up. (average 3.6 years). We found no significant difference with respect to age, sex and diagnosis between the 2 groups. Diabetics did have a significantly higher BMI (30.2 versus 27.7, p< 0.001) and higher incidence of coronary artery disease (31% versus 15%, p< 0.001) We found no increase in the rate of deep periprosthetic infection, superficial wound complications, dislocation, blood loss and DVT between diabetics and non-diabetics even after adjusting for potential confounders of age, sex, diagnosis, BMI and the presence of coronary artery disease. The only factor that was found to be significantly different between the 2 groups was length of stay (10.73 versus 9.56 days, p< 0.05). Further analysis of the diabetic group only showed no difference with regard the same outcomes between insulin-dependent, diet-controlled and diet and oral hypoglycaemic-controlled patient subsets. From this study we conclude that at the time of taking informed consent from diabetic patients undergoing total hip arthroplasty the only potential difference from non-diabetics is that the length of stay may be longer

Problem: Deep infection after hip- or knee-replacement is a severe complication that may lead to implant removal or arthrodesis. Aim: In our hospital intraoperativ subcoutanues culture samples were taken before wound closure. We wanted to know if positive cultures are of any predicitive value in relation to early or late periprosthetic infection. If so, is there a consequence in treatment ? Also costs were analysed. Material and methods: In 2002 we performed 167 primary hip and knee replacements. We retrospectivaly analysed the outcome of 159 cases over a follow-up period of up to 28 month. Results: In 96.8% of the cases a culture sample was taken. Of these 5.8% showed germ growth. In only 4 cases positive cultures were followed by a change in treatment, either antibiotics or revision. Of nine patients with revision surgery only one had a positive culture. Four cases showed germ growth during revision surgery after sterile cultures during implantation. Most often different bacterias were found in primary and revision surgery. In 1.25% deep periprosthetic infection occured. One required second stage knee-replacement, one case ended in resection arthroplasty. Conclusion: Intraoperative culture sample is of no predictive value in primary joint replacement. There is no correlation between positiv cultures and indication for revision surgery. However costs for culture analysis and antibiotics are low compared to the increase of expense caused by periprosthetic infections

Bacteriophage state currently an attractive alternative for antibiotics, especially due to the strong in vitro activity and lack of side effects. Eight patients with chronic infection in musculoskeletal system.are presented. This group includes: 3 cases of deep periprosthetic infection, posttraumatic osteomyelitis of tibia in 2 cases, infected pseudoarthrosis of femur in 1 case, chronic hematogenous osteomyelitis of tibia in 1 case, chronic infection in diabetic foot in 1 case. Adequate tissue specimen for bacteriology was taken during operation and selection of bacteria strains was subsequently done and appropriate phage were cultured. Phage were taken orally by patients 4–6 weeks after operation. Despite of paralel phage and systemic antibiotic administration all patients underwent operative debridement of infected bone. Simultaneously, every 7 days parameters of immunological response was measured in peripheral blood. They were: lymphocyte B activity (PFC and SAC test), lymphocyte T (NK) activity and phagocytose stimulation (PMA 30 test). There was a two-fold increase of lymphocyte B activity in PFC test with peak on day 7 after phage administration. Additionally slightly increase of NK cells and phagocytic activity and both increase and decrease of lymphocyte B and T activity in SAC test was observed. Eventually remission of infection was achieved in 6 from 8 patients. It is difficult to state a correlation between in vitro bactericidal effect of bacteriophage, immunological stimulation in peripheral blood and clinical results achieved after both operative and antimicrobial therapy

Introduction: Deep periprosthetic infections are infrequent but devastating situations in total joint arthroplasty. During the last years the total number and the percentage of total joint infections with multiresistant bacteria has increased. The aim of this study was to investigate the antimicrobial activity of a new bone cement loaded with nanoparticulate silver against bacteria with different antibiotic resistance. Material and Methods: An in vitro proliferation test was used to test antimicrobial properties of 1% nanoparticulate silver bone cement, gentamicin-loaded, tobramycin-loaded and plain bone cement. This in vitro testing method consisted of two incubation steps. During the first step the tested bacteria could adhere to the bone cement surface. In the second step bacteria either seeded out of vital daughter cells in case of no antimicrobial effect of the cement or were killed by the antibacterial properties of the cement. Seeding out of daughter cells was detected by a microplate reading system resulting in specific time proliferation curves. Several staphylococci and gram-negative strains with different resistance profiles against methicillin, tobramycin, and gentamicin were tested including MRSA and MRSE. Results: 1% nanoparticulate silver bone cement showed bactericidal effect against all tested strains, including MRSA and MRSE. Gentamicin and tobramycin cement was not effective against bacteria with high resistance level against the respective antibiotic. Plain bone cement was not effective against any strain. Conclusion: 1% nanoparticulate silver bone cement exhibited excellent antibacterial properties that could not be reached by gentamicin or tobramycin-loaded cement. Good activity against MRSA could also already be shown in a first animal trial. If further in vivo investigations confirm these promising results nanoparticulate silver bone cement is a new alternative for prophylaxis in total joint arthroplasty

Introduction: One of the primary complications in total hip and knee arthroplasty is infection. One of the major risk factors for deep periprosthetic infection is wound infection. This alone is associated with a substantial morbidity-increase which, in turn, increases hospital admittance time and therefore adds significant costs to the healthcare system. The aim of this study is to determine whether contamination of instruments used during primary insertion of a prosthesis, can be considered an early indicator for the occurrence of prolonged wound discharge. Early antibiotic treatment could then prevent this and decrease hospital admittance time and costs to the health care system. Material and Methods: During 121 procedures, swabs were taken from the first unused broach at the beginning and at the end of the procedure. Removed material from the bone (acetabulum and femur in the hip joint; femur and tibia in case of the knee joint) was tested for contamination as well. During 50 procedures a control swab was taken. The patients on the ward were also monitored to find out whether prolonged wound discharge occurred and to see after how many days the patients were discharged. Results: In 46 cases (38%) at least one culture showed microbial growth. In the other 75, there was no growth at all. If one of the cultures is positive, there is a 52% risk of prolonged wound discharge. Ifall cultures are negative, this risk is reduced to 13% (Chi-square: PO.001). Patients with a positive peroperative culture have to remain in the hospital for an additional 2.4 days (T-test: P-0.001). Conclusion: Peroperative culturing during primary insertion of a knee or hip prosthesis, provides a reliable tool to predict postoperative duration of wound discharge and hospital-admittance time

The purpose of this randomized controlled trial is to evaluate the efficacy of using dilute betadine versus sterile saline lavage in aseptic revision total knee (TKA) and hip (THA) arthroplasty to prevent acute postoperative deep periprosthetic joint infection (PJI). Of the 450 patients that were randomized, 5 did not have 90-day follow-up, 9 did not receive the correct treatment, and 4 were excluded for intraoperative findings consistent with PJI. 221 Patients (144 knees and 77 hips) received saline lavage only and 211 (136 knees and 75 hips) received a three-minute dilute betadine lavage (0.35%) prior to wound closure. Patients were observed for the incidence of acute postoperative deep PJI within 90 days of surgery. Statistical analysis was performed using t-tests or Fisher's exact test where appropriate. Power analysis determined that 285 patients per group are needed to detect a reduction in the rate of PJI from 5% to 1% (alpha=0.05, beta=0.20). There were seven PJIs in the saline group and one in the betadine lavage group (3.2% vs. 0.5%, p=0.068). There were no significant differences in any baseline demographics between groups suggesting appropriate randomization. Although we believe the observed difference between treatments is clinically relevant, it was not statistically significant with the sample size enrolled thus far and enrollment is ongoing. Nonetheless, we believe that these data suggests that dilute betadine lavage is a simple method to reduce the rate of acute postoperative PJI in patients undergoing aseptic revision procedures

Deep peri-prosthetic infection after partial or total knee arthroplasty is a disconcerting problem for patient and surgeon alike. The diagnosis of infection is sometimes obvious but frequently requires that the surgeon maintain a substantial index of suspicion for infection as the cause of pain or poor outcome after any joint arthroplasty. While surgical debridement with component retention is appropriate in a subgroup of patients with an acute peri-prosthetic infection, most delayed and chronic infections are best treated with component resection. With carefully selected patients and very aggressive debridement protocols some success has been demonstrated in Europe with single-stage exchange for infection. Most surgeons in North America, however, are unfamiliar with the very aggressive debridement techniques employed at European centers that promote single stage replant; and few surgeons in North America are currently comfortable in cementing a hinged total knee replacement in place for the typical infected TKA nor do they have the patience to re-prep and drape with an entirely new OR setup after debridement and prior to the insertion of the new implant − 2 steps that are often mentioned as important to the success of single stage exchange. The pre-eminent role of two-stage exchange as the definitive treatment was established over 30 years ago. Two-stage exchange remains the gold-standard in treatment with an established track record from multiple centers and with multiple different types of infecting organisms. Some of the historical problems with two-stage exchange, such as limited mobility during the interval stage, have been mitigated with the development of effective articulating spacer techniques. Further, the emergence of drug resistant bacteria and the possibility of fungal infection make two-stage exchange the best choice for the majority of patients with deep periprosthetic joint infection in 2017

Aims

The aim of this study was to report patient and clinical outcomes following robotic-assisted total knee arthroplasty (RA-TKA) at multiple institutions with a minimum two-year follow-up.

Introduction. The current recommendation by the AAOS in the 2010 clinical practice guidelines for the use of MRI to diagnose a periprosthetic joint infection (PJI) is “inconclusive” given the lack of evidence to support its use. The purpose of this study was to determine the utility of MRI with metal reduction artifact sequencing in diagnosing a periprosthetic joint infection (PJI) after total hip arthroplasty (THA). Methods. 176 patients who underwent MRI with multi-acquisition variable resonance image combination (MAVRIC) to reduce metal artifact for a painful THA between the years of 2009–2013 were retrospectively evaluated. All MRIs were read by one of four radiologists with extensive experience in interpreting MRIs after THA. All MRIs were performed using a 1.5 Tesla magnet. Of the 176 patients examined, 16 patients were found to have a deep periprosthetic joint infection using Musculoskeletal Infection Society (MSIS) criteria after the MRI was performed. MRI reads were classified as either positive (read as “evidence of active infection” or “suspicious for infection”) or negative (read as no evidence of infection). Only one patient who had a positive MRI read was excluded because of loss to followup after the MRI was performed. Results. Of the 160 aseptic patients, only one patient was read as suspicious for infection (false positive rate = 0.6%, specificity=99.4%, negative predictive value (NPV)=98.8%). Of the 16 patients with an infected THA, 14 patients were read as positive for infection (false negative rate=12.5%, sensitivity = 87.5%, positive predictive value (PPV)=93%). Conclusion. MRI with metal reduction artifact sequence is a highly specific test to diagnose or rule out a PJI with a low false positive rate and excellent PPV and NPV however, given its lower sensitivity than published for the serum C-reactive protein, is not recommended as a general “screening” test for all patients with pain after THA to rule out infection

Introduction. The current recommendation by the AAOS in the 2010 clinical practice guidelines for the use of MRI to diagnose a periprosthetic joint infection (PJI) is “inconclusive” given the lack of evidence to support its use. The purpose of this study was to determine the utility of MRI with metal reduction artifact sequencing in diagnosing a periprosthetic joint infection (PJI) after total hip arthroplasty (THA). Methods. 176 patients who underwent MRI with multi-acquisition variable resonance image combination (MAVRIC) to reduce metal artifact for a painful THA between the years of 2009–2013 were retrospectively evaluated. All MRIs were read by one of four radiologists with extensive experience in interpreting MRIs after THA. All MRIs were performed using a 1.5 Tesla magnet. Of the 176 patients examined, 16 patients were found to have a deep periprosthetic joint infection using Musculoskeletal Infection Society (MSIS) criteria after the MRI was performed. MRI reads were classified as either positive (read as “evidence of active infection” or “suspicious for infection”) or negative (read as no evidence of infection). Only one patient who had a positive MRI read was excluded because of loss to followup after the MRI was performed. Results. Of the 160 aseptic patients, only one patient was read as suspicious for infection (false positive rate = 0.6%, specificity=99.4%, negative predictive value (NPV)=98.8%). Of the 16 patients with an infected THA, 14 patients were read as positive for infection (false negative rate=12.5%, sensitivity = 87.5%, positive predictive value (PPV)=93%). Conclusion. MRI with metal reduction artifact sequence is a highly specific test to diagnose or rule out a PJI with a low false positive rate and excellent PPV and NPV however, given its lower sensitivity than published for the serum C-reactive protein, is not recommended as a general “screening” test for all patients with pain after THA to rule out infection

Objective. Bacterial infection is a serious complication after joint replacement surgery. In particular, methicillin-resistant Staphylococcus aureus (MRSA) and epidermidis(MRSE) are very difficult to eradicate in infected prosthetic joint. Therefore, the retention rate of initial prosthesis affected with such resistant microorganisms is still low. Gentian violet shows potent antibacterial activity against gram-positive cocci as minimal bactericidal concentration is less than 0.1 %. In the present study, we investigated the efficacy of treatment with gentian violet against MRSA and MRSE infections after THA, TKA, and bipolar hip hemiarthroplasty (BHP). Methods. There were 8 patients in this study; five patients with deep periprosthetic MRSA infection (2 THA, 2 BHP, 1 revision TKA); 3 patients with MRSE infection (1 revision THA, 1 BHP, 1 TKA). When infection was suspected after the surgery, we quickly obtained synovial fluid and periprosthetic soft tissue from the joint and applied to culture and microscopic examinations for detection of microorganisms. After identification of bacterial species, we immediately debrided the affected joint and washed thoroughly twice with 0.1% solution of gentian violet for 3 minutes each, followed by intra-articular multiple injection of arbekacin sulfate solution. Then we inserted an aspiration tube into the joint and administered appropriate antibiotics intravenously. If the inflammatory symptoms persisted in spite of the first treatment, we repeated the treatment until inflammation signs and intra-articular microorganisms could not be detected. Results. At first we examined the bactericidal activity of gentian violet solution against MRSA and MRSE by culture examination with or without the solution. We confirmed gram-negative bacillicould be alive but the both MRSA and MRSE could not be alive by the treatment with 0.01 % solution of gentian violet for 3 minutes. The treatment with gentian violet allowed subsidence of the infection in all patients. Furthermore, we could preserve 4 prostheses with MRSA infection; 1 THA, 1 revision TKA and 2 BHPs; 2 prostheses with MRSE infection; 1 TKA, 1BHP. However, we could not preserve 2 prostheses, 1 THA with MRSA infection and 1 revision THA with MRSE infection. Thus, the prosthetic retention rate of this study for MRSA and MRSE infections was 75 %. We performed two-stage operation for the 2 patients in whom we could not preserve the prostheses as follows: after excision of the infected total hips followed by successful reimplantation. Moreover, all of the patients in this study are able to keep the walking ability after joint replacements. Conclusion. Infection of methicillin-resistant Staphylococcus species after joint replacement surgery has tended to increase. Gentian violet exerts a potent antibacterial activity against such microorganisms at the concentration of less than 0.1 %. We obtained good retention rate by the treatment using gentian violet against MRSA and MRSE infections after the joint surgeries. In addition, both MRSA and MRSE have not showed drug resistance for gentian violet. Therefore, we suggest that gentian violet will become a promising adjunct agent for infection after joint replacement surgery not only methicillin-sensitive but also methicillin–resistant Staphylococcus species