Infected Knee Prosthesis Research Articles

Irrigation and Debridement

Irrigation and Debridement

A ′two-staged retention coverage reconstruction protocol′ for early exposed septic knee prosthesis with patellar ligament disruption

Background The worst scenario in total knee arthroplasty is early wound breakdown causing prosthesis exposure and necrosis of the patellar ligament. We describe a new protocol for the salvage of early exposed septic knee prosthesis with patellar ligament disruption. Patients and methods Between October 2001 and August 2010, 15 patients (15 knees) presenting with early infected, exposed knee prosthesis with patellar ligament disruption were treated using this new protocol. Strict criteria were used for patient selection suitable for this plan of treatment. Patients had to have presented within 30 days of the index arthroplasty. In addition, no radiographic signs of osteitis or loose prosthetic component were present. In the first stage, thorough debridement accompanied by polyethylene insert removal was performed, along with intraprosthetic antibiotics-impregnated cement spacer insertion. This was followed by a 1-week parentral antibiotic regimen. On the eighth day, a second-stage procedure was performed with spacer removal and new polyethylene insertion, accompanied by medial gastrocnemius flap transposition for prosthesis coverage and patellar ligament reconstruction. Results At the latest follow-up (55.2 months), 13 knees (86.6%) have been retained; Knee Society knee and functional scores in these averaged 79.6 and 74 points, respectively, and these patients had regained sufficient extensor mechanism function to return to ambulation. Conclusion We recommend this protocol for the management of early exposed infected knee prosthesis with patellar ligament disruption. Level of evidence Level IV.

Oral Antibiotic Therapy

Oral Antibiotic Therapy

Usefulness of Adding SPECT/CT to 99mTc-Hexamethylpropylene Amine Oxime (HMPAO)-labeled Leukocyte Imaging for Diagnosing Prosthetic Joint Infections

This study evaluated the usefulness of adding single-photon emission computed tomography (SPECT)/computed tomography (CT) (SPECT/CT) to technetium Tc 99m (Tc) hexamethylpropylene amine oxime (HMPAO)-labeled leukocyte imaging for diagnosing infections in hip or knee joint prostheses. The Tc-HMPAO-labeled leukocyte scans of 164 patients (71 with hip prostheses and 93 with knee prostheses) with clinically suspected prosthetic infections were reviewed retrospectively. Planar images were taken 4 to 6 and 21 to 26 hours after injecting the labeled leukocytes and SPECT/CT images were obtained 4 to 6 hours after the injection. The final diagnosis of infection was based on pathologic findings (n = 70), bacteriological data (n = 61), or clinical follow-up (n = 33). Of the 164 patients, 89 patients had a diagnosis of prosthetic joint infections. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the planar images alone were 82.0%, 88.0%, 89.0%, 80.5%, and 84.8%, respectively. When the planar images were combined with SPECT, the sensitivity, specificity, PPV, NPV, and diagnostic accuracy were 91.0%, 88.0%, 90.0%, 89.2%, and 89.6%, respectively. When the planar images were combined with SPECT/CT, these values increased further to 93.3%, 93.3%, 94.3%, 92.1%, and 93.3%, respectively. Adding CT to SPECT resulted in a greater increase in sensitivity and specificity for hip prosthesis infections than for knee prosthesis infections. SPECT/CT mainly contributed by precisely localizing the anatomical site of the active inflammatory lesion and by delineating the extent of the lesion after diagnosis with SPECT. Single-photon emission computed tomography/CT combined with Tc-HMPAO-labeled leukocyte imaging was useful for diagnosing prosthesis infections, particularly in hip prosthesis infections, as it improved diagnostic accuracy and provided anatomical localization data.

Cementless modular intramedullary nail without bone-on-bone fusion as a salvage procedure in chronically infected total knee prosthesis: long-term results

Our purpose was to evaluate long-term results of two-stage cementless intramedullary nailing without achieving bone-to-bone fusion for treating chronically infected total knee arthroplasty (TKA). Thirty-eight patients treated according to the same protocol were retrospectively evaluated for clinical, functional, laboratory and radiological outcomes. Spacer exchange was necessary for infection persistence in one case. At a minimum two year follow-up, 34 patients (89.5%) showed no infection recurrence; among these 34 patients, 29 (85.3%) reported no or moderate pain [visual analogue scale (VAS) ≤3]; mild to moderate handicap (Lequesne Algofunctional Index < 7.5) was observed in 18 patients (52.9%). No patient underwent revision for aseptic loosening, and no nail breakage was observed. Two-stage cementless intramedullary nailing without achieving bone-to-bone fusion is a viable option for treating chronically infected TKA in selected, complex cases.

Two-stage revision for infected total knee arthroplasty: our experience with interval prosthesis

To review our practice of performing two-stage revision for infected total knee arthroplasty using articulating interval prosthesis and to compare the incidence of the recurrence of infection and re-operation rate in patients undergoing two-stage revision as planned with the group of patients who choose not to proceed to the second stage. This study is a retrospective review of 60 consecutive patients undergoing a two-stage revision for infected total knee arthroplasty using articulating interval prosthesis. All cases managed by a single surgeon using a uniform peri-operative protocol, and short-course parenteral antibiotic therapy. Thirty-four patients (57%) (Group 1) underwent the two-stage revision as planned. However, twenty-six patients (43%) (Group 2) opted not to have a second-stage procedure as the first-stage and interval prosthesis had eradicated the infection, resolved the pain and achieved good functional outcome. There were five cases of recurrent infection in the 60 patients (8%) at a mean follow-up 5 years. In those completing the two-stage revision, two patients had recurrent infection. Of the patients who retained the interval prosthesis, there were three recurrent infections. There was no statistically significant difference between the groups in terms of recurrence of infection or re-revision. Two-stage revision with interval prostheses represents a safe and reliable method of treating infected knee prosthesis; however, there may be a role for one-stage revision in selected cases.

“Salvage Microbiology”: Detection of Bacteria Directly from Clinical Specimens following Initiation of Antimicrobial Treatment

BackgroundPCR coupled with electrospray ionization mass spectrometry (ESI-MS) is a diagnostic approach that has demonstrated the capacity to detect pathogenic organisms from culture negative clinical samples after antibiotic treatment has been initiated. [1] We describe the application of PCR/ESI-MS for detection of bacteria in original patient specimens that were obtained after administration of antibiotic treatment in an open investigation analysis.MethodsWe prospectively identified cases of suspected bacterial infection in which cultures were not obtained until after the initiation of antimicrobial treatment. PCR/ESI-MS was performed on 76 clinical specimens that were submitted for conventional microbiology testing from 47 patients receiving antimicrobial treatment.FindingsIn our series, 72% (55/76) of cultures obtained following initiation of antimicrobial treatment were non-diagnostic (45 negative cultures; and 10 respiratory specimens with normal flora (5), yeast (4), or coagulase-negative staphylococcus (1)). PCR/ESR-MS detected organisms in 83% (39/47) of cases and 76% (58/76) of the specimens. Bacterial pathogens were detected by PCR/ESI-MS in 60% (27/45) of the specimens in which cultures were negative. Notably, in two cases of relapse of prosthetic knee infections in patients on chronic suppressive antibiotics, the previous organism was not recovered in tissue cultures taken during extraction of the infected knee prostheses, but was detected by PCR/ESI-MS.ConclusionMolecular methods that rely on nucleic acid amplification may offer a unique advantage in the detection of pathogens collected after initiation of antimicrobial treatment and may provide an opportunity to target antimicrobial therapy and “salvage” both individual treatment regimens as well as, in select cases, institutional antimicrobial stewardship efforts.

Pathogen-driven decision for implant retention in the management of infected total knee prostheses

In prosthetic joint infections (PJIs) of the knee, debridement with implant retention is associated with a high risk of recurrence. A single-centre cohort study was performed with extensive analysis of the literature covering 1980-2012. In 21 patients (mean age 80.4 years, 19 immunosuppressed), in association with 1.5-three months of antibiotic treatment, an attempt was made to salvage the prosthesis by open (11 patients) or arthroscopic (ten patients) debridement. After a mean follow-up of seven years (range four-20 years), patients were in remission in seven cases (33 %). Remission was achieved in 0 % of all methicillin-resistant Staphylococcus aureus (MRSA) infections (zero/three), in 0 % (zero/three) of methicillin-resistant coagulase-negative staphylococcal infections, in 29 % (two/seven) of methicillin-sensitive S. aureus infections and in 75 % (three/four) of infections due to streptococci. The literature review focused on implant preserving approaches yielded 599 cases with an overall success rate of 47 % (284/599) and significantly more remissions in streptococcal vs staphylococcal knee PJIs (43/54 vs 144/324; p < 0.01, odds ratio 4.9, 95 % confidence interval 2.4-10.9). In addition to established indications for explantation such as implant loosening, sinus tract or methicillin resistance, the decision for debridement and retention of knee PJIs should also depend on the pathogen. Implant preservation is futile with methicillin-resistant staphylococci, but seems to be a valid option for streptococcal PJIs.

Meningitis or Epidural Abscesses After Neuraxial Block for Removal of Infected Hip or Knee Prostheses

Background Infection, whether localized or systemic, can be a relative contraindication to neuraxial anaesthesia. Data correlating neuraxial anaesthesia and the development of meningitis or epidural abscess in this setting are limited. Methods Retrospective chart review was performed on 710 medical records of patients admitted between 1998 and 2009 for removal of potentially infected total hip and total knee prostheses. Ultimately, 474 patients were identified as being infected. Factors that predisposed a patient to an immunocompromised state, and signs and symptoms of infection in the pre-, intra-, and postoperative stages were documented. Bacteraemic patients were reviewed for signs of neuraxial infection. The endpoint of follow-up was development of complications before hospital discharge. Results All 474 patients had removal of the infected prosthesis under neuraxial anaesthesia. Mean patient age was 65.5 yr (58% >65 yr) and mean length of hospital stay was 21 days. Patient characteristics included concurrent disease (65%), steroid use (5.3%), preoperative antibiotic use (50.8%), signs of inflammatory process (84%), bacteraemia (4.2%), and documented positive intraoperative joint cultures (88%). Using clinical standards for diagnosis of central neuraxial infection, patients developed infectious complications (incidence of 0.6% on 95% confidence interval), although three patients had findings attributable to anaesthesia, including epidural haematoma, psoas abscess, and back pain. Conclusions Based on clinical criteria, our findings suggest that the incidence of central nervous system infection after neuraxial anaesthesia in patients with infected hip and knee prostheses is low after neuraxial block.

Use of temporary implants (spacers) in revision knee arthroplasty

There is currently no consensus concerning the best option of a spacer for two-stage arthroplasty with an infected knee prosthesis. This retrospective study examined case histories of 16 patients who underwent two-stage revision surgery with use of re-sterilized prosthesis elements as spacers. The results of operations, which were performed within the same period (2004–2010) with use of cement spacers (8 patients), were retrospectively analysed. During the postoperative observation period, which averaged 21 months, 24 cases (100 %) developed control over infection, good or excellent clinical results being observed in 18 cases. Two patients did not undergo reimplantation. The patients, treated with re-sterilized elements, had a greater range of movements during the period between the two operations. Reimplantations with use of prosthetic spacers lasted less time, blood losses were lower. We believe that re-sterilized prosthesis elements are a reliable and efficient alternative to cement spacer for treating infected prosthetic knee joint.

Meningitis or epidural abscesses after neuraxial block for removal of infected hip or knee prostheses

Infection, whether localized or systemic, can be a relative contraindication to neuraxial anaesthesia. Data correlating neuraxial anaesthesia and the development of meningitis or epidural abscess in this setting are limited. Retrospective chart review was performed on 710 medical records of patients admitted between 1998 and 2009 for removal of potentially infected total hip and total knee prostheses. Ultimately, 474 patients were identified as being infected. Factors that predisposed a patient to an immunocompromised state, and signs and symptoms of infection in the pre-, intra-, and postoperative stages were documented. Bacteraemic patients were reviewed for signs of neuraxial infection. The endpoint of follow-up was development of complications before hospital discharge. All 474 patients had removal of the infected prosthesis under neuraxial anaesthesia. Mean patient age was 65.5 yr (58% >65 yr) and mean length of hospital stay was 21 days. Patient characteristics included concurrent disease (65%), steroid use (5.3%), preoperative antibiotic use (50.8%), signs of inflammatory process (84%), bacteraemia (4.2%), and documented positive intraoperative joint cultures (88%). Using clinical standards for diagnosis of central neuraxial infection, patients developed infectious complications (incidence of 0.6% on 95% confidence interval), although three patients had findings attributable to anaesthesia, including epidural haematoma, psoas abscess, and back pain. Based on clinical criteria, our findings suggest that the incidence of central nervous system infection after neuraxial anaesthesia in patients with infected hip and knee prostheses is low after neuraxial block.

The pediculated gastrocnemius muscle flap as a treatment for soft tissue problems of the knee - indication, placement and results.

With the increase of endoprosthetic knee replacements, there is also an increase of critical wounds to the knee due to a high incidence of soft tissue problems (ranging from wound healing defects to severe wound infections). The literature describes a general rate of soft tissue complications of up to 20% [1], [2], with 5% [3] involving exposed bone. These complications are an increasingly important problem for surgeons. Since sufficient coverage of bones, tendons and prosthetic material with soft tissue is a necessity, the use of a pediculated muscle flap is the only solution in some cases. The gastrocnemius muscle is very useful for this purpose. It is an elaborate procedure which is associated with a high rate of complications. However, this procedure can establish a secure coverage with soft tissue, and the function of the prosthesis and the patient’s extremity can be saved. We have treated 23 patients with a gastrocnemius rotation flap after knee prosthesis or knee arthrodesis infection with consecutive soft tissue damage at our hospital from 8/2004 through 3/2011. The overall rate of healing of the knee infections with stable soft tissue status is almost 87%. The revision rate with lifting of the flap and revision of the sutures at the point of insertion as well as the point of extraction was about 35% with long-term conservative or additional surgical treatments.

High Rate of Infection Control with One-stage Revision of Septic Knee Prostheses Excluding MRSA and MRSE

The rate of infection control for one-stage revision of infected knee arthroplasties is unclear as are the factors influencing infection control. Such factors include duration of infection and the type of infected prosthesis. We therefore determined: (1) the rate of infection control with one-stage revision of septic knee prostheses, (2) the clinical knee scores that can be achieved, (3) whether the duration of infection or the type of prosthesis influence the level of infection control, and (4) whether different types of prostheses influence the knee scores. We retrospectively reviewed prospectively collected data from 63 patients who underwent one-stage revisions of septic knee endoprostheses (six unicondylar, 37 primary total knee replacement prostheses, and 20 hinged knee endoprostheses) between 2004 and 2006. All were treated locally and systemically with microorganism-specific antibiotics. For this study we excluded patients with Methicillin-resistant Staphylococcus aureus and Methicillin-resistant Staphylococcus epidermidis or unknown microorganisms. The patients were examined for infection every 3 months and Oxford and Knee Society scores were assessed at the same time. The minimum followup was 24 months (mean followup, 36 months; range, 24-70 months). None of the patients with replacement unicondylar and primary total knee replacement prostheses had recurrence of infection. Three of the 20 patients with the hinged infected knee prostheses had recurrences; these three patients had chronic infections and had undergone two to three revision operations during at least a 5-year period. The likelihood of infection control was influenced by the duration of infection. The mean Knee Society knee score 24 months after surgery was 72 points (range, 20-98 points), the Knee Society function score was 71 points (range, 10-100 points), and the Oxford-12 knee score was 27 points (range, 13-44 points). One-stage revision of septic knee prostheses achieved an infection control rate of 95% and higher knee scores than reported for two-stage revisions. Higher rates of recurrent infection appeared to be associated with long-term chronic infections of hinged prostheses.

Abiotrophia defectiva knee prosthesis infection: A case report

BackgroundAbiotrophia species have rarely been implicated in osteoarticular infections. We report one case of an A. defectiva knee prosthesis infection.Case presentationA 71-year-old man of Italian origin presented with pain and swelling of the knee four years after the implantation of a total knee replacement prosthesis. While standard culturing of the synovial fluid resulted in no isolation of microorganisms, the direct inoculation of the synovial fluid into a rich culture medium resulted in the identification of A. defectiva by polymerase chain reaction sequencing. Repeated attempts of culturing microorganisms from blood were negative, and echocardiograms and colonoscopies were unremarkable. High-dose amoxicillin for nine months and a two-stage replacement of the knee prosthesis led to full patient recovery by the time of the 12-month follow-up examination.ConclusionsBecause Abiotrophia spp. are fastidious microorganisms, it is likely that cases of Abiotrophia orthopedic infection are misdiagnosed as culture-negative infections. Direct inoculation of synovial fluids into rich broth medium and further polymerase chain reaction-based detection of culture-negative synovial fluids are key tests for accurate documentation and detection of these infections.

Adjunctive Rifampin Is Crucial to Optimizing Daptomycin Efficacy against Rabbit Prosthetic Joint Infection Due to Methicillin-Resistant Staphylococcus aureus

Daptomycin is an attractive option for treating prosthetic joint infection, but the 6-mg/kg of body weight/day dose was linked to clinical failure and emergence of resistance. Using a methicillin-resistant Staphylococcus aureus (MRSA) knee prosthesis infection in rabbits, we studied the efficacies of high-dose daptomycin (22 mg/kg given intravenously [i.v.] once daily [o.d.]; equivalent to 8 mg/kg/day in humans) or vancomycin (60 mg/kg given intramuscularly [i.m.] twice daily [b.i.d.]), both either alone or with adjunctive rifampin (10 mg/kg i.m. b.i.d.). After partial knee replacement with a silicone implant, 10(7) MRSA CFU was injected into the knees. Treatment started 7 days postinoculation and lasted 7 days. Positive cultures were screened for the emergence of mutant strains, defined as having 3-fold-increased MICs. Although in vivo mean log(10) CFU/g of daptomycin-treated (4.23 ± 1.44; n = 12) or vancomycin-treated (4.63 ± 1.08; n = 12) crushed bone was significantly lower than that of controls (5.93 ± 1.15; n = 9) (P < 0.01), neither treatment sterilized bone (2/12 and 0/12 rabbits with sterile bone, respectively). Daptomycin mutant strains were found in 6/12, 3/12, and 2/9 daptomycin-treated, vancomycin-treated, and control rabbits, respectively; no resistant strains emerged (MIC was always <1 mg/liter). Adjunctive rifampin with daptomycin (1.47 ± 0.04 CFU/g of bone [detection threshold]; 11/11 sterile bones) or vancomycin (1.5 ± 0.12 CFU/g of bone; 6/8 sterile bones) was significantly more effective than monotherapy (P < 0.01) and prevented the emergence of daptomycin mutant strains. In this MRSA joint prosthesis infection model, combining rifampin with daptomycin was highly effective. Daptomycin mutant strains were isolated in vivo even without treatment, but adjunctive rifampin prevented this phenomenon, previously found after monotherapy in humans.

Outcome and Predictors of Treatment Failure in Total Hip/Knee Prosthetic Joint Infections Due to Staphylococcus aureus

Variables associated with the outcome of patients treated for prosthetic joint infections (PJIs) due to Staphylococcus aureus are not well known. The medical records of patients treated surgically for total hip or knee prosthesis infection due to S. aureus were reviewed. Remission was defined by the absence of local or systemic signs of implant-related infection assessed during the most recent contact with the patient. After a mean posttreatment follow-up period of 43.6 ± 32.1 months, 77 (78.6%) of 98 patients were in remission. Retention of the infected implants was not associated with a worse outcome than was their removal. Methicillin-resistant S. aureus (MRSA)-related PJIs were not associated with worse outcome, compared with methicillin-susceptible S. aureus (MSSA)-related PJIs. Pathogens identified during revision for failure exhibited no acquired resistance to antibiotics used as definitive therapy, in particular rifampin. In univariate analysis, parameters that differed between patients whose treatment did or did not fail were: American Society of Anesthesiologists (ASA) score, prescription of adequate empirical postsurgical antibiotic therapy, and use of rifampin combination therapy upon discharge from hospital. In multivariate analysis, ASA score ≤2 (odds ratio [OR], 6.87 [95% confidence interval {CI}, 1.45-32.45]; P = .04) and rifampin-fluoroquinolone combination therapy (OR, 0.40 [95% CI, 0.17-0.97]; P = .01) were 2 independent variables associated with remission. The results of the present study suggest that the ASA score significantly affects the outcome of patients treated for total hip and knee prosthetic infections due to MSSA or MRSA and that rifampin combination therapy is associated with a better outcome for these patients when compared with other antibiotic regimens.

Gait analysis in patients with a preformed articulated knee spacer

Two-stage revision is one of the most widely accepted procedures to eradicate infection and restore function in infected knee prosthesis; while the use of an articulated spacers is advocated by many as a means to preserve function between stages, no data are available regarding gait parameters after spacer implant. The aim of present study was to assess and compare the gait parameters of patients with articulated knee spacers with a normal reference population and with the sound limb.Computerised gait analysis, was performed 8 to 14weeks after the infected knee prosthesis had been removed and a preformed, articulated, knee spacer had been implanted, in 10 consecutive patients.Kinematic data show a mean gait velocity reduction of 70% and a decrease of the range of motion of the operated knee of 59%, compared with controls. While ground reaction forces were only slightly reduced, frontal and sagittal moments and calculated powers around the affected knees were near zero or zero.Our findings point out the ability of a preformed articulated spacer to preserve, although reduced, the normal gait parameters and joint range of motion and the capacity of the human body to provide useful postural modifications, even in the absence of the proprioceptive input from a normal knee or from a traditional total knee replacement.

The infected knee prosthesis

Deep infections are among the most severe complications in total knee arthroplasty; infection rates described in recent articles range between 1 and 2%. The most important infection risk prevention measures are skin preparation, antibiotic prophylaxis, and screening and management for methicillin-resistant Staphylococcus aureus (MRSA). Debridement and prosthesis preservation is indicated for acute postoperative infections or for acute hematogenous disseminations over well performing prostheses. The following criteria should be met for the result to be favorable: short delay from onset of symptoms (less than 2–3 weeks), Gram-positive germs, absence of prolonged wound drainage and presence of a stable implant. Two-stage replacement is currently the gold standard for treating chronic prosthetic knee infections. The survival rate free of implant removal for reinfection with this technique stands at 93% at 5 years and 85% at 10 years. Moreover, initial recovery figures are preserved with the passage of time. Survivorship free of implant removal for any reason is 90% at 5 years and 77% at 10 years. Articulated spacers seem to be better than static ones. Polymicrobial and Gram-negative infections can be controlled in late knee arthroplasty infections. On the other hand, infections by MRSA are less likely to be controlled by the standard regimens. Preoperative prophylactic antibiotics do not affect the results of intraoperative cultures and therefore they should not be withheld before surgery for an infected TKA when an organism has been identified on aspiration preoperatively, and there has been no recent (4 weeks) antimicrobial therapy.

Timing of DVT Prophylaxis and Risk of Postoperative Knee Prosthesis Infection

This multicenter prospective study was performed to determine risk factors for knee prosthesis infection and the effect of timing doses of prophylactic low-molecular-weight heparins (LMWH) related to time of surgery on the risk of knee prosthesis infection. A total of 5496 consecutive patients who underwent total knee arthroplasty from 2005 to 2006 in 13 orthopedic centers were prospectively followed up for 6 months, and the incidence of knee prosthesis infection was recorded. A case control study was nested in the cohort. Case patients were matched to uninfected (control) patients, and the timing of perioperative LMWH was recorded as the main risk factor. Fifty patients developed postoperative knee prosthesis infection during the follow-up period, yielding an incidence of prosthesis infection of 0.91% (95% CI, 0.68%-1.20%). Forty-four patients were matched to 106 controls. Case patients received the first LMWH dose ±12 hours from the start of surgery more frequently than their control counterparts (odds ratio, 1.5; 95% CI, 0.73-3.0). After adjusting by main risk factors, no statistical association was found between close perioperative timing of LMWH and risk of prosthesis infection. Diabetes mellitus (adjusted odds ratio, 3.2; 95% CI, 1.2-8.8) and wound hematoma (adjusted odds ratio, 4.2; 95% CI, 1.1-16.5) were found to be independent risk factors for prosthesis infection.

High-dose antibiotic infusion for infected knee prosthesis without implant removal

BackgroundRetention of a prosthesis represents an attractive surgical modality for the infected but well-fixed knee prosthesis because patients need to stay in bed after removal of all components. Some additional postoperative treatment would be needed, however, when treated only with débridement because of its low success rate. MethodsIn this study, intraarticular antibiotic infusion into the infected joints after débridement, while retaining the implants, was performed for six well-fixed total knee arthroplasties (TKAs), one revision TKA, and five tumor megaprostheses with an average follow-up period of 47.5 months (range 20–82 months). TKA patients with a polyethylene insert or those with all exchangeable components and all polyethylene parts in tumor megaprostheses underwent device removal and thorough débridement of the soft tissues. Subsequently, new polyethylene inserts were implanted in the TKA patients. The removed metallic prostheses were resterilized and reimplanted, and new polyethylene inserts were implanted in the tumor megaprostheses patients. The wound was closed in layers after insertion of a catheter percutaneously. The patients received organism-specific intraarticular antibiotics through the catheter twice a day until the infection disappeared clinically. ResultsThere was no recurrence of infection in the TKA and revision TKA patients. Four of five knees treated with tumor megaprostheses exhibited recurrence of the infection. Infection was finally healed, however, in all cases by the same treatment procedure. ConclusionsAlthough some patients experienced recurrence of infection, successful implant salvage was achieved in all cases with the same treatment procedure. Patients do not need to stay in bed during this treatment. Therefore, this method should be considered as one of the treatment options for infected knee prostheses.