Two-stage Exchange Procedure Research Articles

Short Course of Oral Antibiotic Treatment After Two-Stage Exchange Arthroplasty Appears to Decrease Early Reinfection

BackgroundRecent evidence has suggested a benefit to extended postoperative prophylactic oral antibiotics after two-stage exchange arthroplasty for treatment of periprosthetic joint infections. We sought to determine reinfection rates with and without a short course of oral antibiotics after two-stage exchange procedures. MethodsA retrospective review identified patients undergoing two-stage exchange arthroplasty for periprosthetic joint infection of the hip or knee. Patients were excluded if they failed a prior two-stage exchange, had positive cultures at reimplantation, prolonged intravenous antibiotics postoperatively, and/or life-long suppression. This resulted in 444 reimplantations (210 hips and 234 knees). Patients were divided into three cohorts based on the duration of oral antibiotics after reimplantation: no antibiotics (102), ≤2 weeks (266), or >2 weeks (76). The primary endpoint was reinfection within 1 year of reimplantation. ResultsWithin 1 year of reimplantation, there were 34 reinfections. In the no-antibiotic, ≤ 2-week, and >2-week cohorts the reinfection rates were 14.1, 7.0, and 6.4%, respectively. Multivariate Cox regression showed a reduced reinfection rate in the ≤2-week cohort relative to no antibiotics (hazard ratio [HR]: 0.38, P = .01). While the smaller cohort with >2 weeks of antibiotics did not significantly reduce the reinfection rate (HR: 0.41, P = .12), when combined with the ≤2-week cohort, use of oral antibiotics had an overall reduction of the reinfection rate (HR: 0.39, P = .01). ConclusionsThese data support the hypothesis that a short course of oral antibiotics after reimplantation decreases the 1-year reinfection rate. Future randomized studies should seek to examine the efficacy of different durations of oral antibiotics to reduce reinfection. Level of EvidencePrognostic Level IV.

Long-term antibacterial activity of vancomycin from calcium phosphate cement in vivo.

Periprosthetic joint infection is a major complication of total joint arthroplasty, with treatment requiring a two-stage exchange procedure and 6 weeks of systemic antibiotics. However, depending on the infection site, intravenous delivery of antibiotics like vancomycin (VCM) can have poor tissue transferability, thus reducing their therapeutic effect. This study demonstrates the 24-week invivo release profile and antibacterial activity of VCM from calcium phosphate cement impregnated with VCM (CPC/VCM) and compares them with those from polymethylmethacrylate impregnated with VCM (PMMA/VCM). Rats were implanted with the test specimens between the fascia and quadriceps. After implantation for 24 weeks, the test specimens were removed and residual VCM was extracted to calculate the concentration of VCM released into rat tissues. We also examined the antibacterial activity of releasable VCM from the removed test specimens by placing them directly onto the surface of agar. CPC/VCM released greater concentrations of VCM for a longer period of time within the 24 weeks than PMMA/VCM. Moreover, CPC/VCM released 1.4 to 26.1-fold more VCM than PMMA/VCM. Using Staphylococcus aureus, antibacterial activity was logarithmically correlated with VCM concentration across the entire concentration range tested (12.5-800μg/mL). While the area within which inhibition was observed-the inhibition zone-for both CPC/VCM and PMMA/VCM formed and gradually shrank with time after implantation, that for CPC/VCM was significantly larger than that for PMMA/VCM in each week after implantation. CPC/VCM releases greater amounts of VCM with antibacterial activity for longer periods of time than PMMA/VCM, suggesting that CPC is effective for facilitating the release of antibiotics for local action in patients with established postoperative infection.

Does the Implementation of the PRO-IMPLANT Foundation Treatment Algorithm Improve the Outcome of Chronic Periprosthetic Knee Infections? Mid-Term Results of a Prospective Study.

Several treatment options for chronic periprosthetic joint infections have been published in the current literature, with an on-going discussion to determine effective management algorithms. To compare outcomes of the two-stage exchange procedure in revision TKA prior to and after implementation of the PRO-IMPLANT Foundation treatment algorithm. The primary endpoints were defined as (i) revisions during the interval time, (ii) duration of the interval time and (iii) successful PJI eradication. Between 02/2013 and 09/2016, 122 patients were included in a single-centre cohort analysis. 55patients were treated according to the previously used algorithm (K1) and 67 according to the PRO-IMPLANT Foundation algorithm (K2). A minimum follow-up period of 3 years was set as the inclusion criterion. Successful eradication of infection was defined in accordance with the consensus criteria by Diaz-Ledezma et al. RESULTS: Successful eradication was achieved in 42 (67%) patients in K1 and 47 (85.5%) in K2 (p ≤ 0.005). The mean interval time was 88 days (range 51 - 353) in K1 and 52 days (range 42 - 126) in K2 (p ≤ 0.005). In K1, a mean of 0.8 (range 0 - 6) revisions were necessary during the interval period compared with 0.5 (range 0 - 4) in K2 (p = 0.066). Implementation of the PRO-IMPLANT treatment algorithm led to significant improvement in the outcome of periprosthetic joint infections. During mid-term follow-up, infection eradication was highly successful, with decreases in the interval time as well as the number of revisions.

Management of Prosthetic Joint Infection following Total Knee Arthroplasty with an Articulating Antibiotic Knee Spacer: An Early Experience

Eradication of deep prosthetic joint infection (PJI) following total knee arthroplasty (TKA) is a vexing problem to patients, surgeons, and the health care system. At present, two-stage exchange is a widely accepted method to treat and resolve PJI following TKA. Various spacers are available following resection arthroplasty and are designed for the local delivery of antibiotics and stability of the knee joint. We report our experience with management of PJI in TKA patients with a novel mobile knee spacer. Methods We retrospectively reviewed 31 consecutive infected knee arthroplasties, (primary TKA, 26) and (revision TKA, 5) performed between 2014 and 2016 treated with two-stage exchanges. The outcome of the spacer cohort and subsequent reimplantation procedure was examined to determine spacer range of motion, postoperative range of motion, and reinfection rate following two-stage exchange. Results Minimal spacer-related complications are reported and a stable knee spacer with flexion up to 95° were observed in most patients. The overall mean ± SD time of interim spacer placement for all patients was 25.7± 21.9 weeks (range, 8-109 weeks). The mean ± SD postoperative follow-up (following reimplantation surgery) was 3.52 ± 1.36 years (range, 1.29-6.03 years). Two patients re-infected and required a second two-stage exchange procedure. Following post second stage reimplantation surgery, all patients demonstrated no evidence of recurrence of infection. Conclusions This customized and modular articulating knee spacer has the potential to significantly reduce spacer-related complications following PJI in both primary and revision TKA and provide enhanced stability and improved knee range of motion. Level of Evidence Prognostic Level IV.

One-stage versus two-stage revision of the infected knee arthroplasty - a randomized multicenter clinical trial study protocol

BackgroundA two-stage prosthesis exchange procedure has been the gold standard in surgical treatment of the chronically infected knee arthroplasty so far. This includes 2 surgeries/hospitalizations and an interim period of 2–3 months between surgeries with impaired health, functional status and quality of life of the patients. A one-stage exchange procedure holds many obvious advantages compared to the two-stage approach, but outcomes of a one-stage versus two-stage procedures have never been investigated in a randomized clinical trial. The purpose of this study is primarily to investigate time-adjusted differences in functional status of patients after one-stage versus two-stage revision. Secondary, to report time-adjusted differences in quality of life, complications (including re-revisions due to infection) and mortality.MethodsThis study is a pragmatic, multi-center, randomized, non-inferiority trial comparing one-stage versus two-stage revision of the infected knee arthroplasty. Seven Danish hospitals are currently participating in the study, but additional hospitals can enter the study if adhering to protocol. Ninety-six patients will be included prospectively. Follow-up will be with PROM-questionnaires and clinical controls up to 10 years. The patients who are not able to participate in the randomized trial are followed in a parallel cohort study.PROM’sOxford Knee Score and EQ5D + EQ5D VAS questionnaires are completed preoperatively and sent out to the study participants at 6 weeks, 3, 6, 9, 12, 18 and 24 months as well as 5 and 10 years postoperatively. In addition a tailor made cost questionnaire on the non-treating hospital resource use, community health and social service use, travel costs, time off work and informal care are sent out.DiscussionIf one of the two treatment alternatives is found superior in both domains of quality of life (both knee-specific and generic) and health economics, that treatment should be promoted. Other outcomes will open informed discussions about treatment strategies for periprosthetic knee infections.Trial registrationThe randomized trial is registered on ClinicalTrials.gov with ID NCT03435679, initial release date January 31, 2018 and the cohort study is registered with ID NCT04427943, submitted January 8, 2020 and posted June 11, 2020.

Risk Factors for Failure and Optimal Treatment of Total Joint Arthroplasty for Septic Arthritis

BackgroundPatients with native joint septic arthritis are one of the highest risk groups for developing complications following total joint arthroplasty (TJA), especially periprosthetic joint infection(PJI). There is a paucity of information on the risk factors for developing PJI and the optimal treatment modality of the native septic joint that can mitigate that risk. This multicenter study aimed to determine these risk factors, including prior treatment. MethodsA retrospective study of 233 TJAs performed, following prior septic arthritis at five institutions, was conducted. Comorbidities, organism profile, prior surgery, etiology of septic arthritis, and other relevant variables were reviewed. The primary outcome was the development of PJI, defined by Musculoskeletal Infection Society criteria. Bivariate and multivariate analyses were performed to identify risk factors for PJI. ResultsOverall, the PJI rate was 12.4% in patients who underwent TJA after native septic arthritis. Predisposing risk factors for PJI included antibiotic-resistant organisms, male gender, diabetes, and a postsurgical cause of septic arthritis eg open reduction internal fixation. When controlling for potential confounders, multivariate analysis revealed that male gender, diabetes, and a postoperative etiology were predictors of PJI. The definitive treatment modality for the septic joint did not affect the rate of PJI for both arthroscopy vs irrigation and debridement (I&D), and two-stage exchange vs single-stage procedure. DiscussionThis study has identified several risk factors for developing PJI in patients with prior septic joint arthritis, some of which are modifiable. The initial treatment modality of the native septic joint has no bearing on the development of PJI after TJA.

Four versus six weeks of antibiotic therapy for osteoarticular infections after implant removal: a randomized trial.

The optimal duration of antibiotic therapy for treating orthopaedic implant infections after surgical drainage and complete implant removal is unknown. This was a single-centre, unblinded, prospective trial randomizing (1:1) eligible patients to either 4 or 6 weeks of systemic, pathogen-targeted antibiotic therapy. Clinical trial registration number: ClinicalTrials.gov (NCT0362209). We analysed 123 eligible patients (62 in the 4 week antibiotic arm and 61 in the 6 week arm) in the ITT analysis. The patients' median age was 64 years, 75 (61%) were men and 38 (31%) were immunocompromised. The most common types of infection treated included: two-stage exchange procedure for prosthetic joint infection (n = 38); orthopaedic plate infection (44) and infected nail implants (11). The median duration of post-explant intravenous antibiotic therapy was 4 days. Overall, 120 episodes (98%) were cured microbiologically and 116 (94%) clinically after a median follow-up period of 2.2 years. During follow-up, four patients had a clinical recurrence with a pathogen other than the initial causative agent. We noted recurrence of clinical infection in four patients in the 4 week arm and three patients in the 6 week arm (4/62 versus 3/61; χ2 test; P = 0.74); in all cases, this occurred at around 2 months following the end of antibiotic treatment. We found no statistically significant difference in the rates of clinical or microbiological remission between patients randomized to only 4 compared with 6 weeks of systemic antibiotic therapy after removal of an infected osteoarticular implant.

Economic Analysis in a Diagnosis Related Groups System for Two-stage Exchange of Prosthetic-joint Infections.

Background: There is a constant increase of joint arthroplasties performed, with an infectious risk of 1-2%. Different therapeutic options for prosthetic-joint infections exist, but surgery remains essential. With a two-stage exchange procedure, a success rate above 90% can be expected. Currently, there is no consensus regarding the optimal interval duration between explantation and reimplantation. This retrospective study aimed to assess the economic impact of a two-stage exchange from a single-hospital perspective.Methods: 21 patients who have undergone a two-stage exchange of a hip or knee prosthetic-joint infection at the University Hospital of Lausanne (Switzerland) from 2012 to 2013 were included. The revenues earned according to the Swiss Diagnosis Related Groups (SwissDRG) system introduced in 2012 and the costs were compared for each hospital stay.Results: The remuneration ranged from 26'806 to 42'978 Swiss francs (CHF) (~ 22'905-36'723 EUR, median 36'338 CHF, ~ 31'049 EUR). The median total cost per patient was 76'000 CHF (~ 65'000 EUR) (51'151 to 118'263; hip median 79'744, knee median 66'708). The main determinant of the costs was the length of the hospital stay. Revenues never covered all the costs, even with a short-interval procedure. The hospital lost a median of 35'000 CHF per patient (~ 30'000 EUR) (22'280 to 64'666).Conclusion: The current DRG system may not be specific enough for rewarding prosthetic-joint infections. Several options could be considered to act on the length of the hospital stay. In order to cover costs in complicated cases, such as prosthetic-joint infections, more specific DRGs are needed.

Bacterial biofilm formation is variably inhibited by different formulations of antibiotic-loaded bone cement in vitro.

The aim of the present study was to quantitatively assess biofilm growth on the surface of bone cements discs containing different antibiotics, including colistin and linezolid. Biofilms of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Staphylococcus epidermidis were grown on bone cement discs for 96h. Biofilm amounts were measured by confocal laser microscopy using live/dead staining and dedicated software at different time intervals (48, 72, and 96h). Bone cement containing vancomycin was not effective at reducing MRSA biofilm formation 96h following bacterial inoculation. At a comparable time interval, linezolid-, clindamycin-, and aminoglycoside-loaded cement was still active against this biofilm. At the 72- and 96-h observations, S. epidermidis biofilm was present only on tobramycin and gentamicin discs. P. aeruginosa biofilms were present on cement discs loaded with colistin at all time intervals starting from the 48-h observation, whereas no biofilms were detected on tobramycin or gentamicin discs. Bone cements containing different antibiotics have variable and time-dependent windows of activity in inhibiting or reducing surface biofilm formation. The effectiveness of bone cement containing vancomycin against MRSA biofilm is questionable. The present study is clinically relevant, because it suggests that adding the right antibiotic to bone cement could be a promising approach to treat periprosthetic infections. Indeed, the antibiofilm activity of different antibiotic-loaded bone cements could be preoperatively assessed using the current methodology in two-stage exchange procedures.

Effect of Sonication on the Elution of Antibiotics from Polymethyl Methacrylate (PMMA).

Background: In the setting of prosthetic joint infections treated with a two-stage procedure, spacers can be sonicated after removal. We hypothesize that the sonication process may cause an increased elution of antibiotics from the spacer, leading to elevated concentrations of antibiotics in the sonication fluid inhibiting bacterial growth. We aimed to evaluate in vitro the influence of sonication on the elution of antibiotics from polymethyl methacrylate (PMMA) over time and to determine whether these concentrations are above the minimum inhibitory concentrations (MIC) for microorganisms relevant in prosthetic joint infections.Methods: PMMA blocks impregnated with vancomycin, fosfomycin, gentamicin or daptomycin were incubated in phosphate-buffered saline (PBS) at 37°C for up to 6 weeks. PBS was changed once a week. Concentrations were determined from samples of each antibiotic every week, and after 5 minutes of sonication at 2, 4 and 6 weeks.Results: With sonication there was a trend toward an increase of the elution of antibiotics. This increase was significant for vancomycin at 2 and 4 weeks (p=0.008 and 0.002 respectively) and for fosfomycin at 2 weeks (p=0.01).Conclusion: The effect of sonication could play a role in clinical results, especially for daptomycin and gentamicin for which the MIC is close to the concentration of antibiotics at 4 and 6 weeks.We conclude that elution of antibiotics from PMMA along with the effect of sonication could inhibit bacterial growth from spacers, resulting in false negative results in the setting of two-stage exchange procedures for prosthetic joint infections.

Clinical outcome of extended trochanteric osteotomy in two-stage revision of periprosthetic hip infection

Objective To investigate the efficacy of using an extended trochanteric osteotomy as part of a two-stage exchange procedure for periprosthetic hip infection. Methods We retrospectively analyzed 16 patients (16 hips) including 9 males and 7 females who had extended trochanteric osteotomy as part of two-stage revision procedure for periprosthetic hip infection from January 2008 to January 2012, the average age was 65.2±6.4 years at the time of operation. The two-stage revision protocol included taking out of all implants using extended trochanteric osteotomy, meticulous debridement, restoration of the osteotomies and fixed with cerclage wiring, implantation of antibiotic bone cement spacer in first stage. After sequential therapy of antibiotics through peripheral vein and enteral prescription, the prosthesis was implanted in the second stage. Harris hip score was used to evaluate the hip function. X-ray radiograph was conducted to evaluate the healing of osteotomy, eradication of infection, prosthesis stability, displacement and looseness. Results All patients were followed-up for 24-90 months (53.4±7.2 months on the average). The interval between the first and second surgery was 8.6±2.1 months with a range from 5-18 months. All osteotomies healed uneventfully, with the average heal time 13.2 ± 1.3 weeks (range from 8 to 16 weeks). The infection was eradicated in 15 hips (93.8%) at the second surgery. One hip with staphylococcus epidermidis infection was confirmed by bacterial culture of synovial fluid in second surgery. Infection symptom disappeared after sequential antibiotic therapy. At the last follow-up, all patients had successful eradication of infection, with Harris score improved from 38.6 ± 5.4 preoperatively to 86.4 ± 3.2. Thirteen patients achieved bone ingrowths, while the other 3 patients had fibrous ingrowths. Two cases had intraoperative fracture, 2 had postoperative spacer dislocation. Conclusion Extended trochanteric osteotomy as part of a two-stage exchange arthroplasty can be performed safely and effectively in periprosthetic hip infection, with reliable osteotomy healing. Furthermore, it does not influence the effects of infection treatment and component stability. Key words: Arthroplasty, replacement, hip; Osteotomy; Prosthesis-related infections; Reoperation

Espaciadores estáticos de cemento con antibiótico en la infección protésica de rodilla. [Static cement spacers in total knee infection. Custom manufacturing technique and postoperative motion.

<p><strong>Introducción: </strong>Conjuntamente al aumento de los reemplazos totales de rodilla (RTR) realizados anualmente se ha incrementado el número de infecciones posteriores a esta cirugía. Está demostrado en la bibliografía mundial que las revisiones en dos tiempos logran mayores porcentajes de curación que las efectuadas en un solo tiempo. El objetivo del presente trabajo es mostrar nuestros resultados en revisiones de RTR infectadas, tratadas en 2 tiempos, con la utilización de espaciadores estáticos.<strong></strong></p><p><strong>Materiales y Método: </strong>Entre 1997 y 2010 se efectuaron en nuestro centro 153 revisiones de RTR de los cuales 33 (21%) fueron a causa de una infección peri protésica crónica, tratada en 2 tiempos con el uso de un espaciador estático de cemento con ATB. La serie se conformó de 33 rodillas en 32 pacientes, con un promedio de edad de 69 años y un seguimiento de 3,5 años.</p><p><strong>Resultados: </strong>De las 33 rodillas se obtuvo la curación en 30 (91%). Veintiocho rodillas fueron reimplantadas exitosamente, 2 rodillas con curación de la infección no fueron reimplantadas por distintos motivos y permanecieron con el espaciador en forma definitiva y en 3 hubo persistencia de la infección.</p><p>De las 28 reimplantadas todas evolucionaron favorablemente, logrando una movilidad de 90° a los 3,15 meses POP en promedio.</p><p><strong>Conclusión: </strong>Con la utilización de espaciadores estáticos de rodilla obtuvimos un porcentaje de curación similar a los publicados con el uso de espaciadores articulados. La ventaja de los primeros es su fácil fabricación y colocación, otorgándole a la articulación una adecuada estabilidad con un bajo costo económico.<strong></strong></p>

Sonication of antibiotic-loaded cement spacers in a two-stage revision protocol for infected joint arthroplasty

BackgroundCulturing of the sonication fluid of removed implants has proven to be more sensitive than conventional periprosthetic tissue culture for the microbiological diagnosis of prosthetic joint infection. Since bacteria surviving on antibiotic-loaded cement spacers used in a two-stage exchange protocol for infected arthroplasties may cause the persistence of infection, in this study we asked whether the sonication also could be used to identify bacteria on antibiotic-loaded cement spacers removed at the second surgical stage during a two-stage exchange procedure to confirm whether or not the prosthetic joint infection had been eradicated.MethodsWe cultured the sonication fluid of cement spacers that had been originally implanted in a two-stage exchange protocol in 21 patients (mean age, 66 years) affected by prosthetic joint infection (16 total knee prostheses and 5 hip prostheses). The cement spacers were vortexed for 30 seconds and then subjected to sonication (frequency 35–40 KHz). The resulting sonicate fluid was cultured for aerobic and anaerobic bacteria.ResultsThe sonication fluid culture of the removed spacer was positive in six patients (29%), with isolation of methicillin-sensible Staphylococcus Aureus (MSSA) in three cases, methicillin-resistant Staphylococcus Aureus (MRSA) in one case and Pseudomonas Aeruginosa in two cases. In three of these positive cases, the traditional culture of periprosthetic tissue was negative. Two patients with positive sonication culture of the spacer were successfully treated by early debridement of the revision prosthesis and systemic antibiotic therapy. In three patients a knee arthrodesis was planned and performed as the second surgical stage. In two of them the infection was caused by highly resistant Pseudomonas Aeruginosa. The other patient with a MSSA infection had been poorly compliant with the systemic antibiotic therapy due to her mental impairment. The patient originally affected by MRSA infection of his primary hip arthroplasty developed recurrent infection of his revision prosthesis and eventually underwent Girdlestone arthroplasty.ConclusionsThe sonication culture can be used to discover any bacteria on the antibiotic-loaded cement spacer during a two-stage exchange protocol, thus permitting the adoption of timely treatment options, such as the early prosthetic debridment.

Paper 107: Prospective Comparative Study Between Static Cement Spacer and Mobile Cement Spacer in Infected Total Knee Arthroplasties

Infection in total knee arthroplasty (TKA) is a devastating complication. The two-stage exchange procedure has evolved as an effective treatment option. The use of antibiotic-impregnated cement spacers may be considered at the first-stage surgery. Spacers may be static or mobile type. This prospective study was undertaken to compare the clinical results achieved using static cement spacer and mobile cement spacer in infected TKA.

The relationship between microbiology results in the second of a two-stage exchange procedure using cement spacers and the outcome after revision total joint replacement for infection

Patients with infected arthroplasties are normally treated with a two-stage exchange procedure using polymethylmethacrylate bone cement spacers impregnated with antibiotics. However, spacers may act as a foreign body to which micro-organisms may adhere and grow. In this study it was hypothesised that subclinical infection may be diagnosed with sonication of the surface biofilm of the spacer. The aims were to assess the presence of subclinical infection through sonication of the spacer at the time of a second-stage procedure, and to determine the relationship between subclinical infection and the clinical outcome. Of 55 patients studied, 11 (20%) were diagnosed with subclinical infection. At a mean follow-up of 12 months (interquartile range 6 to 18), clinical failure was found in 18 (32.7%) patients. Of the patients previously diagnosed with subclinical infection, 63% (7of 11) had failed compared with 25% (11 of 44) of those without subclinical infection (odds ratio 5.25, 95% confidence interval 1.29 to 21.4, p = 0.021). Sonication of the biofilm of the surface of the spacer is useful in order to exclude subclinical infection and therefore contributes to improving the outcome after two-stage procedures.

Management of the infected shoulder prosthesis: a retrospective analysis and review of the literature

Experience with infected shoulder arthroplasty is limited. Treatment options are either one- or two-stage reimplantation, débridement with retention of the prosthesis, resection arthroplasty or arthrodesis. We retrospectively analysed ten patients with an infected shoulder prosthesis and evaluated the diagnostic and therapeutic management as well as the clinical outcome, assessed by the Constant score, Neer's criteria and the mean abduction ability. We identified an infecting organism before surgery in nine patients. Four patients were treated by two-stage exchange reimplantation, five by resection arthroplasty and one underwent serial débridement combined with vacuum-irrigation therapy. Infection was eradicated in all patients of this series. The mean Constant score in resected patients was 32.7, in patients treated by stage exchange 40.1 (no difference) and we measured 90 points in the patient with retention of the implant. In patients treated by resection arthroplasty, merely the mean abduction yielded a better result (63 vs 31°) than in patients treated by two-stage exchange-with the pain level being identical in both groups. Treatment of infected shoulder implants in patients who often have to deal with concomitant diseases remains unsatisfactory. Two-stage exchange procedures yielded only slightly better functional results than resection arthroplasty, which should be considered in cases of elderly or chronically ill patients because it offers good pain relief. Serial débridement combined with irrigation therapy is a new method which offers good clinical results, however with an unknown risk of persisting infection. The authors recommend isolating the infecting organism prior to surgery to allow the administration of organism-specific antibiotics as early as possible during surgery in order to efficiently eradicate the infection.

The use of two-stage exchange arthroplasty with depot antibiotics in the absence of long-term antibiotic therapy in infected total hip replacement

We present a series of 114 patients with microbiologically-proven chronically-infected total hip replacement, treated between 1991 and 2004 by a two-stage exchange procedure with antibiotic-loaded cement, but without the use of a prolonged course of antibiotic therapy. The mean follow-up for all patients was 74 months (2 to 175) with all surviving patients having a minimum follow-up of two years. Infection was successfully eradicated in 100 patients (87.7%), a rate which is similar to that reported by others, but where prolonged adjuvant antibiotic therapy has been used. Using the technique described, a prolonged course of systemic antibiotics does not appear to be essential and the high cost of the administration of antibiotics can be avoided.

Technique and Timing of Two-stage Exchange for Infection in TKA

Infection in total knee arthroplasty is a devastating complication. The two-stage exchange procedure has evolved as an effective treatment option. The classification and alternatives to a two-stage procedure are presented. Current diagnosis and monitoring of infection in total knee arthroplasty with laboratory, aspiration, and imaging techniques are reviewed. The timing, technique, and results of a two-stage procedure are discussed. A knee aspiration with synovial fluid cell count and culture may be a useful adjunct. The use of antibiotic-impregnated cement spacers may be considered at the first-stage surgery. Spacers may be static or articulating, intramedullary dowels, preformed or constructed in the operating room, and provide single- or multiple-agent antibiotic (and antifungal) joint space delivery. Proper technique, antibiotic dosing, and indications with these devices will avoid complications between stages. The most common complications encountered with the use of spacers include dislocation/instability, implant extrusion, overstuffing of the patellofemoral and tibiofemoral joints, and implant or periprosthetic fracture. At the second stage of the procedure, surgical exposure, intraoperative frozen sections, assessment of bone and soft tissue defects, the integrity of the extensor mechanism, and implant selection are important factors to consider in the second-stage reimplantation revision total knee arthroplasty. Level V, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

A complication of the acrylic block technique in the delayed exchange for an infected knee arthoplasty

Two-stage exchange procedures appear to give the most consistent results in the management of the deep infection after the Total Knee Arthroplasty w x 1,3,5,7,8,10,11 . The use of an antibiotic impregnated polymethw x ylmethacrylate 4 spacer block in the interval after radical primary debridement, provides antibiotic delivery, preserves some movement and stability and perhaps greater patient comfort and mobility. We report a subluxed acrylic block used in the first stage causing significant compromise of a vascularised medial gastrocnemius flap used to repair a soft tissue defect after debridement. This case suggests that in an effort to prevent both migration and translation of an acrylic block, intra-operative fashioning of the spacer block should include intramedullary projection on both femoral and tibial sides.