the number of total joint arthroplasties ( tjas ) performed has increased steadily in recent years , with projected numbers for the coming years rising further . consequently according to recent data , peri - prosthetic joint infection ( pji ) incidence constitutes between approximately 0.3% and 1.7% of all total hip arthroplasties ( tha ) , and between 0.8% and 1.9% of all total knee arthroplasties ( tka ) . pji can be classified in intra - operative , early post - operative , acute haematogenous and chronic infections , according to both timing and cause of infection . the risk factors potentially correlated with acute pji infection can be divided into pre - operative ( usually related to patient comorbidities ) , peri - operative and post - operative , which are mainly linked to the behaviours of the surgeon and the hospital staff . conversely , chronic infections are less influenced by the conduct of the surgeon , as they are most often related to haematogenous diffusion of bacteria . the aim of this paper is to review the recent literature , summarising the most relevant risk factors that the surgeon can modify in order to reduce the incidence of peri - prosthetic joint infection . several studies demonstrated that some comorbidity can be associated with an increased risk of pji . the american academy of orthopaedic surgeons ( aaos ) reported on the different risk factors for pji and developed a guideline for pji prevention and treatment . in 2013 consensus for definition , prevention and management of pji , as an update to the previous guidelines . potential risk factors for development of surgical site infection or peri - prosthetic joint infection after elective total joint arthroplasty , according to the international consensus on periprosthetic joint infection bmi , body mass index ; hba1c , glycated haemoglobin . although the majority of these conditions must be considered as non - modifiable factors , many preventive measures may be adopted to reduce their impact on the development of pji . table 2 summarises the modifiable and non - modifiable factors related to pji , including some preventive measures to manage reversible medical comorbidities , according to the existing literature . pre - operative modifiable and non - modifiable risk factors ; measures the surgeon can adopt to reduce impact of risk factors on development of pji pji , peri - prosthetic joint infections ; bmi , body mass index ; hba1c , glycated haemoglobin ; mrsa , methicillin - resistant staphylococcus aureus ; s. aureus , staphylococcus aureus other potential pre - operative risk factors are intra - articular corticosteroid injections and any infectious disease , particularly urinary tract infection ( uti ) and nasal colonisation with staphylococcus ( s. ) aureus . the relationship between steroid injections and post - operative pji was evaluated in several studies . papavasiliou et al reported an incidence of only 2% of infections in a series of 114 tkas , but all of the infected tkas had previously been treated with an intra - articular corticosteroid injection within the 11-month period prior to surgery . conversely , desai et al stated that the incidence of infection did not increase in patients with prior steroid injection treatment . the correlation between post - operative utis and pji has been demonstrated . however , the association between pre - operative bacteriuria and early deep infections remains uncertain . the presence of symptoms of a uti in association with urinary leukocyte counts greater than 1  10/ml and a bacterial count greater than 1  10/ml should be the only indication for surgical delay . conversely , in asymptomatic patients it is still possible to proceed with tja by treating those patients with urine colony counts greater than 1  10/ml . different authors confirmed that being a high - level nasal carrier of s. aureus is an important and significant independent risk factor for developing ssi with s. aureus . nasal application of mupirocin is widely accepted as treatment for nasal carriers of s. aureus . in a recent randomised controlled trial ( rct ) , mupirocin treatment resulted in a simple , safe and cost - effective intervention that can reduce the risk of ssi . different intra - operative components may play an important role as risk factors for developing pji ( table 3).the first six hours following surgery are the most important regarding infection , as during those hours the numbers of bacteria multiply exponentially . maintaining a low blood level of bacteria in this period is critical , and for this reason prophylactic antibiotics are infused to decrease bacterial multiplication and to extend this  golden period . the pre - operative dose of antibiotics should be administered within one hour before the surgical incision ; this can be extended to two hours for vancomycin and fluoroquinolones . most authors agree that a single pre - operative prophylactic infusion of cefazolin ( 1 gr if < 80 kg ; 2 gr if > 80 kg ) is a good choice . however , recent studies have demonstrated that targeted use of vancomycin and cefazolin among patients undergoing revision tka significantly reduced the rate of overall infections , in particular of mrsa . surgeons should consider additional antibiotic administration if the surgery time is twice the length of the half - life of the antibiotic , or whenever the blood loss exceeds 2000 ml and fluid resuscitation is over 2000 ml . to reduce pji infection rate , some authors advocate using antibiotic - loaded bone cement ( albc ) for the cementation . however , it was demonstrated that routine use of albc does not change the pji rate , though it may be useful in the reduction of the pji rate in high - risk patients ( for example those with diabetes or immunosuppression ) . intra - operative factors potentially associated with pjis pji , peri - prosthetic joint infections surgical site preparation also plays a role in reducing pji rate . some authors have confirmed the reduction of pji in patients who underwent pre - admission surgical site preparation using chlorhexidine washing . different studies have evaluated the best solutions for surgical site preparation to reduce pji . in a rct conducted by darouiche et al , it was demonstrated that a chlorhexidine  alcohol solution was more protective than povidone  iodine against both superficial and deep infections . this is probably due to the more rapid action , persistent activity despite exposure to bodily fluids , and residual effect of chlorexidine compared with povidone . the preparation of the surgical site often includes using plastic adhesive drapes and sterile stockinette . however , a recent cochrane review showed no evidence that adhesive drapes reduce surgical site infection rates . the bactericidal action of incision drapes containing iodine is inferior to conventional skin preparation solutions , so using incision drapes as a substitute for conventional skin preparation is not recommended . furthermore , boekel et al concluded that the surgical field for tka can be contaminated by proximal microbial spread from the unprepared foot with the use of a sterile stockinette drape . the risk of pji is also directly correlated with the length of the surgery , which should be less than 2.5 hours as a reasonable cut - off point . zhu et al , in their meta - analysis , concluded that increased operative time is associated with a higher risk of pji development ( or = 2.18 , ci 95% 1.39 - 3.42 , p = 0.003 ) . however , these data may also be correlated with the high complexity of long procedures . furthermore , the surgeon s surgical volume may be directly associated with pji : surgeons with low volumes may have higher rates of infection . hand care is another crucial point in reducing pji infection ; hand surgical scrub recommendations were previously published by the centers for disease control and prevention . in particular , surgeons should remove debris from underneath the fingernails using a nail cleaner under running water , and either an antimicrobial soap or an alcohol - based hand rub should be used persistently for at least five minutes . different studies evaluated the number of glove changes necessary to reduce the risk of pji . of note , beldame et al recommended : renewing outer gloves after draping ( before placing a cutaneous adhesive ) ; opening the instrumentation secondarily , with a new glove change after handling instruments which may cause perforations ; renewing outer gloves after each surgical stage . no strong evidence is available in the literature regarding the appropriate number of glove changes . different authors recommended double gloving to reduce the risk of inner glove perforation , but no correlation with pji has been demonstrated . the role of the personal protection system ( pps ) in preventing pji is still debated . kearns et al demonstrated that the external surface of the pps can not be assumed to be sterile after removal from the original packaging , and they suggested the need to change gloves if the pps is touched or adjusted during the procedure . other authors agree with the consideration of pps as more a personal  protection than equipment specifically to reduce pji . light handles can be a source of contamination , and surgeons must minimise their handling as far as possible . furthermore a limited number of portable devices such as mobile telephones and tablet computers in the operating room is recommended , although no evidence in the literature is able to link their use to increased risk . as airborne pathogens are a potential source of infection , the location and length of time that surgical instruments remain exposed for this reason , all instruments should be opened in operating rooms with clean air systems . these basins are repeatedly used during a surgical procedure and should therefore be considered a potential source of contamination . anto et al demonstrated that 23.8% of specimens from splash basins tested positive for bacterial contamination , and they suggested that surgeons should stop using them . a recent systematic review showed no conclusive results regarding the utility of laminar flow in reducing pji rate . other authors agree that , despite the number of previous studies demonstrating the efficacy of laminar flow , more recent research has failed to prove this efficacy . ultraviolet light seems to be more effective when compared with laminar flow in reducing pji ; however it is characterised by potentially unacceptable health costs to operative personnel . a level iii study showed that the number of door openings had a role in increased infection rate . surgeons may also play a role in reducing the rate of pji using power - pulsed lavage or wound lavage at surgery . in a level iv study , different post - operative variables may also play a role as risk factors for pji development . antibiotic prophylaxis for other surgical procedures before and after tja , such as dental care or urological procedures , seems to play a role as a despite the lack of literature demonstrating the relationship between dental procedures and pji , the current recommendation of the aaos is to use antibiotic prophylaxis in patients with a tja who are undergoing dental procedures , as well as any other invasive procedure . furthermore , patients should be aware that any infection is a potential source of haematogenous dissemination . as previously reported by different authors , patients with tja who have an active infection anywhere in the body are at risk of developing a pji . for this reason , a prompt diagnosis and management of those infections is a mandatory prevention mechanism . there is still debate regarding the association between blood transfusion and pji . in a level ii study , pulido et al demonstrated that transfusion with allogenic blood is an independent risk factor for pji . patients receiving allogenic transfusions were 2.1 times more likely to develop pji compared with patients receiving no transfusion . in their study , innerhofer et al concluded that allogenic filtered transfusion is an independent variable for pji prediction ( or 23.65 ; ci 95% , 1.3 - 422.1 ; p = 0.01 ) . furthermore , the centers for disease control and prevention guidelines defined peri - operative allogeneic transfusion as a potential risk factor for developing pji , but concluded that the interpretation of the existing literature is difficult due to variations in assessment criteria . however , different measures can be adopted to reduce the need for blood transfusion , such as pre - operative screening for anaemia and its treatment , intra - operative accurate haemostasis , minimisation of surgical time and use of tranexamic acid . haematoma and persistent wound drainage were also related to an increased pji rate ; these conditions should be treated promptly with antibiotic prophylaxis , a decrease in anticoagulation dose , surgical evacuation of the haematoma , irrigation and debridement and modular component exchange . recently , more advanced surgical bandages such as hydrofibre absorbent dressings were proposed , with the aim of reducing the medication to allow for better wound healing and to prevent bacteria from entering the wound site from the external environment . in a level ii study , cai et al concluded that advanced surgical dressings such as hydrofibre may contribute to a reduction in the incidence of acute pji . infection represents a major challenge in tja , and is costly and demanding to manage for both surgeons and patients . the main risk factors involved in pji development are divided into pre - operative , intra - operative and post - operative factors . the surgeon can act to reduce the impact of some reversible comorbidities , for example controlling glycaemia in diabetic patients or improving malnutrition . various intra - operative risk factors such as operating theatre traffic , use of light handles , pulsed lavage or number of glove changes may also be related to infection . post - operative risk factors include transient bacteraemia related to dental procedures or other infections , wound care and blood transfusion as well as haematoma , and wound drainage should be controlled with care . no benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article .
total joint arthroplasty ( tja ) is one of the most common orthopaedic procedures . 
 nevertheless , several complications can lead to implant failure.peri-prosthetic joint infections ( pji ) certainly represent a significant challenge in tja , constituting a major cause of prosthetic revision . 
 the surgeon may have an important role in reducing the pji rate by limiting the impact of significant risk factors associated to either the patient , the operative environment or the post - operative care.in the pre - operative period , several preventive measures may be adopted to manage reversible medical comorbidities . 
 other recognised pre - operative risk factors are urinary tract infections , intra - articular corticosteroid injections and nasal colonisation with staphylococcus ( s. ) aureus , particularly the methicillin - resistant strain ( mrsa).in the intra - operative setting , protective measures for pji include antibiotic prophylaxis , surgical - site antisepsis and use of pre - admission chlorhexidine washing and pulsed lavage during surgery . in this 
 setting , the use of plastic adhesive drapes and sterile stockinette , as well as using personal protection systems , do not clearly reduce the risk of infection . 
 on the contrary , using sterile theatre light handles and splash basins as well as an increased traffic in the operating room are all associated with an increased risk for pji.in the post - operative period , other infections causing transient bacteraemia , blood transfusion and poor wound care are considered as risk factors for pji.cite this article : ratto n , arrigoni c , rosso f , bruzzone m , dettoni f , bonasia de , rossi r. total knee arthroplasty and infection : how surgeons can reduce the risks . 
 efort open rev 2016;1 : 339 - 344 doi : 10.1302/2058 - 5241.1.000032 .