Antibiotic-loaded Cement Research Articles

Prosthetic joint infections: diagnosis, management, and complications of the two-stage replacement arthroplasty.

Despite improved strategies to prevent prosthetic joint infection, as the total number of joint replacements increases, so does the absolute number of infections. Radiography serves as the first-line imaging modality for the assessment of a suspected prosthetic joint infection. Additionally, serial radiographs acquired after a surgery to eradicate a prosthetic joint infection are an important clinical tool. Prosthetic joint infections are often treated with a 2-stage replacement arthroplasty utilizing a prosthesis with antibiotic-loaded acrylic cement. While complications are uncommon with this procedure, imaging may demonstrate periprosthetic fractures, as well as spacer migration, joint dislocation, and spacer fracture. We describe the classification of prosthetic joint infections, the clinical and imaging diagnosis, and treatment strategies. Familiarity with the hardware utilized in the management of the prosthetic joint infection, and its potential complications is fundamental to accurate imaging interpretation.

The cost-effectiveness of antibiotic-loaded bone cement versus plain bone cement following total and partial knee and hip arthroplasty

BackgroundPostoperative infection is one of the most prevalent complications following total joint arthroplasty (TJA). As such procedures become more prevalent, it is imperative that we develop new prophylactic methods to prevent the need for revision procedures. In recent years, surgeons have opted to use antibiotic-loaded bone cement (ALBC) rather than plain bone cement (PBC) in primary hip and knee replacements due to its theoretical potential of lowering infection rates. However, the cost-effectiveness of this intervention remains in question.Questions/Purposes: To determine the rate of infection and cost-effectiveness of antibiotic-loaded bone cement as compared to plain bone cement in hip and knee arthroplasty. Patients and methodsWe reviewed 4116 primary hip and knee arthroplasty cases performed between 2016 and 2018 at Morristown Medical Center in New Jersey. Data regarding demographics, complications, and any readmissions due to deep infection were collected retrospectively. During that time period there were a total of 4016 knee cases (423 ALBC, 3593 PBC) and 123 hip cases (63 ALBC, 60 PBC). The average cost for one bag of antibiotic-loaded bone cement and plain bone cement for hip and knee arthroplasty was $336.42 and $72.14, respectively. A statistical analysis was performed using Fisher's exact test; the National Healthcare Safety Network (NHSN) surgical site infection guidelines were used to distinguish between superficial and deep infections. ResultsTen patients were readmitted due to deep infection, all of whom had undergone total knee arthroplasty. Of those cases, plain bone cement was used for the index procedure in seven instances and antibiotic-loaded cement was used in three. This resulted in an infection rate of 0.19% and 0.62%, respectively, p = 0.103. There was no statistically significant difference in infection rates between the two groups. A total of 778 bags of ALBC were used in 423 knee surgeries, and 98 bags of ALBC were used in 63 hip cases. The total cost for ALBC in TKA and THA procedures was $261,734.76 (778*336.42) and $32,969.16 (98*336.42), respectively. If PBC had been used during all index procedures, it would have resulted in a total savings of $231,509.28. ConclusionsAntibiotic-loaded cement did not significantly reduce the rate of infection for either knee or hip arthroplasty. Thus, the routine use of antibiotic-loaded cement in primary hip and knee arthroplasty may be an unnecessary financial burden to the healthcare system. A larger sample size and a randomized controlled trial would help confirm our findings and would provide further information on the cost-effectiveness of ALBC cement versus PBC.Significance/Clinical Relevance: In this review of cases performed from 2016 to 2018 there was no statistically significant difference between the rate of infection and the need for revision surgeries for patients treated with ALBC versus PBC. As hospital systems continue to transition towards a bundled payment model, it becomes imperative for providers to reduce any unnecessary costs in order to increase quality and efficiency. We estimate that our hospital system could save nearly $120,000/year by using plain bone cement instead of antibiotic-loaded cement.

Clinical Results of Antibiotic-Loaded Acrylic Cement Attachment for the Treatment of Pyogenic Arthritis and Infected Total Knee Arthroplasty

Clinical Results of Antibiotic-Loaded Acrylic Cement Attachment for the Treatment of Pyogenic Arthritis and Infected Total Knee Arthroplasty

Comparision of knee range of movement by using static verses dynamic spacer in total knee infection

Introduction: Prosthetic joint infections (PJIs) of total knee arthroplasty (TKA) are the one of the most dreaded complications resulting from TKA. Although different methods of treatment protocols are followed around the world, a two staged exchange arthroplasty is the considered gold standard for PJI’s. The purpose of the present study was to determine the recovery of knee ROM in patients undergoing two stage revision total knee arthroplasty with either dynamic or static antibiotic loaded cement spacers. Methods: This was a retrospective case series performed between 2016 and 2019, Patients with a documented TKA infection that under-went a two-stage revision of both the femoral and tibial component of their TKA were included into the study. A total number of 44 patients who were treated with a spacer made of antibiotic-loaded acrylic cement were included. Twenty two patients were treated with temporary static spacer and 22 patients were treated with dynamic spacers. Results: At 6 months post operative visit, none of the patients had a recurrence in infection. Knee flexion was higher in dynamic spacer group at 2 week, 3 months and 6 months during the post operative period when compared to static spacer group the operation time of revision implantation was also shorter for dynamic spacer group. Conclusion: Our study results suggest that patients treated with dynamic spacer had a faster recovery in terms of range of motion of the knee, and shorter operating time for reimplantation. Our results support the use of dynamic spacers in an infected TKA that are treated with two-stage revision of arthroplasty.

Intramedullary reaming modality for management of postoperative long bone infection: a prospective randomized controlled trial in 44 patients

BackgroundStudies addressing the management of intramedullary infection are mainly retrospective and with a limited number of cases. Reaming can be performed using either conventional reaming or using the reamer/irrigator/aspirator (RIA) system. Until now there have been no comparative prospective studies between these two methods. We aimed to compare the efficacy of RIA with conventional reaming followed by insertion of antibiotic-loaded cement, for the treatment of intramedullary nail infection of long bones. We assessed the rate of remission between groups after two-year follow-up and identified microorganisms using tissue cultures and sonication of explanted intramedullary nail (IMN).MethodsA noninferiority, randomized clinical trial was carried out between August 2013 and August 2015 involving 44 patients of whom a locked IMN implant of the femur and/or tibia was retrieved and who all met the clinical and radiological criteria for IMN-associated osteomyelitis. Patients were randomized into two groups: RIA alone versus conventional reaming followed by antibiotic-loaded cement insertion. Both groups also underwent six-weeks of antibiotic treatment according to the results of the antibiogram. Patients were evaluated after 1, 3, 6, 12 and 24 months for radiological and clinical follow-up.ResultsAfter 24 months, the rate of infection remission was similar between the two groups, 87% in the RIA group and 95.5% in the conventional reaming group (p = 0.60). Among four patients who had recurrence of infection, the time to reappearance of symptoms varied from 20 days to twenty-two months. Staphylococcus aureus and coagulase-negative Staphylococci were isolated in 23 (40.4%) and 13 (22.9%) patients, respectively. Interestingly, we identified 20% (9/45) of polymicrobial infection.ConclusionThis study concludes that the RIA system alone, is noninferior to conventional reaming followed by antibiotic cement spacer in the treatment of IMN infection. However, RIA shows greater efficacy in the collection of infected medullary bone tissue, mainly in cases of infected retrograde nail of the femur.Trial registrationISRCTN82233198. Retroactively registered on July 29, 2019.

Does the use of a closed-suction drain reduce the effectiveness of an antibiotic-loaded spacer in two-stage exchange Arthroplasty for Periprosthetic hip infection? A prospective, randomized, controlled study

BackgroundThere is a concern regarding the use of a closed-suction drain (CSD) in two-stage exchange arthroplasty for periprosthetic joint infection as it may decrease the antibiotic concentrations in the joint fluids. The purpose of this study was to identify whether the use of a CSD could reduce local antibiotic concentrations following spacer implantation.MethodsA prospective, randomized, controlled trial was conducted at our institution between January 2018 and November 2018. We enrolled 32 patients undergoing two-stage exchange arthroplasty for periprosthetic hip infection with an interim cement spacer containing 4-g vancomycin and 2-g meropenem per 40-g methyl-methacrylate cement polymer. Patients were randomized and evenly divided into the study group (non-CSD) and control group (CSD group) by sealed envelopes. Drainage samples of joint fluids (n = 160) were collected every 24 h for the first five days following spacer implantation. The antibiotic concentrations of drainage samples were measured by high-performance liquid chromatography, and the bioactivities of the drainage samples against methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA) and E. coli were assessed.ResultsThere was no significant difference in the decrease of vancomycin (study group vs. control group: 163.20 ± 77.05 vs. 162.39 ± 36.31; p = 0.917) and meropenem concentration (123.78 ± 21.04 vs. 117.27 ± 19.38; P = 0.548) between the two groups during the first five days following spacer implantation. All joint drainage samples in each group exhibited antibacterial activity against MSSA, MRSA and E. coli.ConclusionsThe use of CSD following the implantation of an antibiotic-loaded cement spacer does not reduce the effectiveness of such a spacer in two-stage exchange arthroplasty.(Chinese Clinical Trial Registry, ChiCTR-INR-17014162. Registered 26 December 2017.)

Reliability of intra-operative frozen section study in revision of infected hip arthroplasty

IntroductionFrozen sections are extensively used to help in the diagnosis of periprosthetic joint infection during revision hip arthroplasty, though there are insufficient data in relation to its usefulness.MethodsTwenty-one patients with infected hip arthroplasties were operated in the form of one or two-staged revision hip arthroplasties. A frozen section was obtained intra-operatively and > 5 PMN’s/ HPF was considered as a positive indicator of infection. If the frozen section was reported negative (≤5 PMN’s/HPF), the revision prosthesis was implanted after a thorough debridement and a wash. If the frozen section was reported as positive, post the debridement; a non-articulating antibiotic-loaded cement spacer was implanted for 8 weeks, supplemented with 3 weeks of intravenous antibiotics and 3 weeks of oral antibiotics. This was followed by an antibiotic-free interval of 2 weeks. The patient was taken up for a revision surgery once the frozen section study was negative (≤5 PMN’s/HPF). The patients were followed up for a minimum of 1 year to a maximum of 2 years after the revision for any evidence of infection (assessed clinically, serologically, and radiologically).ResultsFrozen section analysis of PMNs per high power field had a 100% specificity in our patients in detecting periprosthetic joint infection.ConclusionFrozen section study is a safe, rapid, cheap and reliable intra-operative modality to diagnose periprosthetic joint infection.

Is short-course systemic antibiotic therapy using an antibiotic-loaded cement spacer safe after resection for infected total knee arthroplasty? A comparative study

Most patients who undergo two-stage exchange arthroplasty surgery for total knee arthroplasty prosthetic joint infection (TKA-PJI) receive a six-week course of systemic antibiotic treatment after the first stage procedure. However, the optimal duration of therapy has not been conclusively determined. We included 64 patients with periprosthetic knee infection who had undergone two-stage exchange arthroplasty. Between March 2003 and December 2009, 21 patients were given a short-course (less than 1 week) antibiotic treatment, and 43 were given a standard-course (4-6 weeks) treatment during the interim period. We compared length of hospital stay, duration of intravenous and overall systemic antibiotic treatments, and rate of recurrent periprosthetic knee infection between groups. Short-course antibiotic treatment was associated with a shorter hospital stay and a shorter duration of intravenous and systemic antibiotic treatment. Implant survival regarding re-resection arthroplasty and chronic oral antibiotic suppression as primary endpoints was not significant different statistically between two groups (p=0.317). The 1-year implant survival rates were 91.7% in the short-course group and 89.8% in the standard-course group. The 5-year implant survival rates were 85.2% and 74.0%, respectively. After the first stage of resection arthroplasty for a two-stage exchange arthroplasty, a short course of antibiotic treatment had similar implant survival rates in comparison to the standard 6-week course. With radical debridement combined with an antibiotic-loaded cement spacer along with serial monitoring of the patient, a short course antibiotic treatment may be adequate in patients with TKA-PJI.

Staged Revision with Antibiotic Spacers for Infected Hindfeet vs One-Stage Revision Using an Ilizarov Ringfixator: What’s Better?

Category:HindfootIntroduction/Purpose:The treatment of hindfeet infections with a two-stage revision surgery using an antibiotic-loaded cement spacer is an established treatment strategy. If the soft tissue situation is critical or if patients do have severe comorbidities, the use of a one-stage procedure, using an Ilizarov ringfixator to perform the arthrodesis is also an option. We wanted to compare the outcome of patients who either received the two-stage revision or the one-stage procedure.The purpose of the study was to determine the likelihood of infection control and radiological consolidation of the arthrodesis after either two-stage or one-stage revision in patients with hindfoot infection, as defined by the Musculoskeletal Infection Society PJI criteria. The postoperative AOFAS score was used to measure the clinical outcome.Methods:Between 1995 and 2015, we treated 12 patients with a two-stage procedure using an antibiotic-loaded cement spacer, followed by antibiotic therapy. The second stage consisted of a hindfoot arthrodesis. Of those, 7 were available for review at a minimum of 24 months. 3 were excluded because they were deceased (due to old age). Two moved abroad, leaving 7 patients for analysis.During the same time period we treated 13 patients with a one-stage hindfoot arthrodesis using an Ilizarov ringfixator. Of those, 10 were available for review at a minimum of 24 months. 2 were excluded because they were deceased due to old age, leaving 10 patients for analysis.The primary outcome included the proportion of patients achieving infection control, defined as the absence of the Musculoskeletal Infection Society PJI criteria. Radiological consolidation on standard foot X-rays was also determined. The clinical outcome was assessed with the AOFAS hindfoot score.Results:Successful infection control in the two-stage revision group was achieved in 6 out of 7 patients (86%). One patient achieved infection control only after a below-knee amputation. The mean AOFAS score at the latest follow-up was 75.Radiological consolidation was achieved in 70% (5 out of 7, with one patient needing an amputation for infection control).In the Ilizarov-group, successful infection control was achieved in 9 out of 10 patients (90%). One patient achieved infection control only after a below-knee amputation. The mean AOFAS score at the latest follow-up was 70. Radiological consolidation was achieved in 80% (8 out of 10, with one patient needing an amputation for infection control).Conclusion:A one-stage arthrodesis using an Ilizarov ringfixator for infection control in infected hindfeet leads to comparable infection control and radiological consolidation as the established two-stage procedure with an antibiotic-loaded cement spacer. The clinical outcome, measured by the AOFAS hindfoot score, is also comparable in both groups. The one-stage procedure using an Ilizarov ringfixator should therefore be considered as a treatment option, when soft tissues or comorbidities do not allow a two-stage procedure. It is an option to avoid a below-knee amputation in those patients.

Treatment of periprosthetic hip infection with retention of a well-fixed stem: six to 13-year outcomes

BackgroundTreatment of periprosthetic joint infection (PJI) is challenging, generally requiring complete implant removal. However, recently reported treatments involve partial retention of implants because of the severe local and systemic burden on the patients and difficulties in functional preservation. Long-term results should be evaluated because of the risk of residual biofilm on the retained implant and late infection recurrence. We evaluated 6 to 13-year clinical outcomes of two-stage treatment of chronic PJI retaining well-fixed cementless stems.MethodsAmong 36 surgeries for deep infection following hip arthroplasty performed from 2004 to 2011, six hips had a well-fixed and well-functioning cementless stem. These six hips were all chronic PJI and were treated without stem removal. The first-stage surgery involved acetabular cup removal and reconstruction by filling the acetabular defect with antibiotic-loaded acrylic cement, creating a socket-like hemispherical dent, and reducing the retained femoral head to this dent. After confirming infection eradication the second-stage acetabular reconstruction was performed. One patient died of an unrelated noninfective cause 1 year after the operation. Clinical outcomes of the remaining five patients were followed for 6 to 13 years.ResultsBetween the two surgeries (range; 2–5 months), patients underwent active range-of-motion and ambulation exercises. No dislocation was found during the interval. No recurrence of infection was found and good functional outcomes and radiographic findings were observed during the average follow-up of 109 months in all five patients.ConclusionsTwo-stage treatment with retention of a well-fixed stem may minimize local and systemic burden of the patient and enhance functional preservation while obtaining long-term infection control. Although further study could establish the effectiveness and indications for this treatment option, currently used indications should be carefully evaluated considering factors including local and systemic conditions of the patient, implant fixation status, and type of bacteria.

Retention of prosthetic articulating spacer after infected hip arthroplasty as a semipermanent implant: A case report

Prosthesis with antibiotic-loaded acrylic cement was designed as a temporary articulating cement spacer in a two-stage procedure before definitive reimplantation for the treatment of periprosthetic joint infections. It is designed to remain in situ for about 6–12 weeks, until evidence of infection is controlled before reimplantation of a definitive total hip replacement. This study presents a case of a patient with prosthetic articulating spacer retention for 6 years, previously performed for an infected unipolar hemiarthroplasty for which he refused second-stage reimplantation. He remains relatively asymptomatic with no evidence of infection, implant loosening, or fracture. The patient is able to walk with a frame with minimal hip pain.

Influence of Fixation Methods on Prosthetic Joint Infection Following Primary Total Knee Replacement: Meta-Analysis of Observational Cohort and Randomised Intervention Studies.

The type of fixation used in primary total knee replacement (TKR) may influence the risk of prosthetic joint infection (PJI). We conducted a systematic review and meta-analysis to assess published evidence linking type of fixation (cemented, uncemented, or hybrid) with the risk of PJI following primary TKR. Randomised controlled trials (RCTs) and observational cohort studies comparing fixation methods and reporting PJI incidence following primary TKR were identified in MEDLINE, Embase, Web of Science, and Cochrane Library up until November 2018. Summary measures were relative risks (RR) with 95% confidence intervals (CIs). We identified 32 eligible articles (24 observational studies and 8 RCTs) involving 1,161,292 TKRs. In pooled analysis of observational studies, uncemented fixation was associated with a decreased overall PJI risk when compared with cemented fixation at 0.76 (0.64–0.89). Comparing antibiotic-loaded cemented fixation with plain cement, there was no significant difference in overall PJI risk at 0.95 (0.69–1.31), but PJI risk was increased in the first 6-month postoperative period to 1.65 (1.12–2.43). Limited data from RCTs showed no differences in PJI risk among the fixation types. Observational evidence suggests uncemented fixation may be associated with lower PJI risk in primary TKR when compared with cemented fixation. In the early postoperative period, antibiotic-loaded cemented fixation may be associated with increased PJI risk when compared with plain cement. This may either reflect appropriate selection of higher risk patients for the development of PJI to cemented and antibiotic-loaded cement or may reflect a lower PJI risk in uncemented TKR due to factors such as shorter operative time.

Hip Spacers in Two-Stage Revision for Periprosthetic Joint Infection: A Review of Literature.

Infection after total hip arthroplasty (THA) is a devastating complication with significant consequences for patients. In literature, single and two-stage revision, irrigation and debridement, Girdlestone resection arthroplasty, and arthrodesis and amputation are reported as possible treatments. Recently, two-stage revision has become popular as the gold standard treatment for chronic hip joint infections after THA. In this review, we evaluate the current literature about microbiology of periprosthetic joint infections and the use of antibiotic-loaded cement spacers. We aim to give an overview about indications, clinical results, and mechanical complications for spacers implantation, evaluating also selection criteria, pharmacokinetic properties, and systemic safety of the most frequently used antibiotics.

A preliminary study of the novel antibiotic-loaded cement computer-aided design-articulating spacer for the treatment of periprosthetic knee infection

BackgroundIn comparison to static spacers, articulating spacers have been shown to result in a similar infection eradication rate in two-stage revision of periprosthetic knee infections. However, the optimal construct for articulating spacers has not been identified yet. The aim of this study was to present a preliminary result of treatment for periprosthetic knee infection using a novel computer-aided design (CAD)-articulating spacer.MethodsWe retrospectively reviewed 32 consecutive cases of chronic periprosthetic knee infection occurring from January 2015 to December 2015. In these cases, we used an antibiotic-loaded, optimized CAD-articulating spacer based on the retrieved knee prosthesis. Evaluation included infection eradication rate, the Hospital of Special Surgery (HSS) knee score, range of motion (ROM), and spacer-related mechanical complications. All cases were regularly followed-up for 2 years minimum.ResultsTwenty-eight of 32 patients (87.5%) had infection eradication; 18 patients (56.3%) received reimplantation successfully. The mean interval between spacer insertion and reimplantation was 8.8 months (range 4.0–12.5 months). The mean HSS knee score and ROM significantly increased during each interval (p < 0.0001 for both). The mean HSS knee scores were 31.2 (range 20–48) at initial visit, 65.4 (range 60–78.8) at 1 month after spacer insertion, and 84.2 (range 78–90) at 3 months after reimplantation (p < 0.0001). The mean ROM were 72.0° (range 15–100°), 85.6° (range 35–110°), and 102.0° (range 80–122°), respectively (p = 0.002). Two (6.3%) spacer-related mechanical complications occurred.ConclusionsThe CAD-articulating spacer in two-staged revision of periprosthetic knee infection significantly controlled infection, improved clinical outcomes, increased ROM, and decreased mechanical complications in the preliminary study. Further larger clinical studies are needed to confirm the findings presented here.

Short-course versus long-course antibiotics in prosthetic joint infections: a systematic review and meta-analysis of one randomized controlled trial plus nine observational studies

Prosthetic joint infections (PJIs) often require long-course antibiotic therapy. However, recent studies argue against the current practice and raise concerns such as the development of antibiotic resistance, side effects of medications and medical costs. To review and compare the outcomes of short-course and long-course antibiotics in PJIs. We conducted a systemic review and meta-analysis using a predefined search term in PubMed and EMBASE databases. Studies that met the inclusion criteria from inception to June 2018 were included. The quality of the included studies was assessed. A total of 10 articles and 856 patients were analysed, comprising 9 observational studies and 1 randomized controlled trial. Our meta-analysis showed no significant difference between short-course and long-course antibiotics (relative risk = 0.87, 95% CI = 0.62-1.22). Additionally, the older the studied group was, the more short-course antibiotics were favoured. When treating PJI patients following debridement, antibiotics and implant retention, an 8 week course of antibiotic therapy for total hip arthroplasty and a 75 day course for total knee arthroplasty may be a safe approach. For two-stage exchange, a shorter duration of antibiotic treatment during implant-free periods is also generally safe with the usage of antibiotic-loaded cement spacers.

The management of infected shoulder arthroplasty by two-stage revision.

There remains no gold standard management for deep shoulder periprosthetic joint infection (PJI). This case series aims to present our experience of two-stage revision arthroplasty, including eradication of infection and reoperation rates. We retrospectively reviewed patients undergoing revision arthroplasty for shoulder PJI between 2006 and 2015. Cases were confirmed using Musculoskeletal Infection Society (MSIS) and American Academy of Orthopaedic Surgeons (AAOS) guidelines. TSA removal, debridement and irrigation preceded antibiotic-loaded cement spacer insertion and a minimum of six weeks intravenous antibiotics. Reimplantation was performed as a second stage following a negative aspirate. Twenty-eight patients underwent a first stage procedure (mean age 69 years; 16 male, 12 female). Propionibacterium acnes, Methicillin-sensitive Staphylococcus aureus, Coagulase-negative Staphylococcus and Staphylococcus epidermidis were the commonest microorganisms cultured. Five cases had mixed growths and six cases provided no growth. Three patients did not proceed to a second stage. Twenty-five patients underwent reimplantation (mean interval 6.7 months), with 80% remaining infection-free (mean follow-up 38.3 months). Managing complex and late presentation shoulder PJI with two-stage revision is associated with high rates of infection eradication (80%). In the absence of a management consensus, our experience supports two-stage revision arthroplasty for eradicating infection in this complex patient group.

Acute kidney injury after hip or knee replacement: Can we lower the risk?

Patients who undergo hip or knee replacement (total joint arthroplasty) face a risk of acute kidney injury that may be higher than previously thought and that increases steeply if they undergo surgical revision to treat prosthetic joint infection. This article assesses the incidence of and risk factors for acute kidney injury after primary total joint arthroplasty or placement of an antibiotic-loaded cement spacer to treat infection, and offers suggestions on how to reduce the risk.

Two-stage reimplantation in periprosthetic knee infection.

The increasing number of total knee arthroplasties performed yearly worldwide has resulted in a concomitant rise in bacterial infections. Two-stage reimplantation has been reported as the most successful method of treating periprosthetic knee infections. The purpose of this study was to describe all the phases of the two-stage reimplantation and to review the literature regarding the topic. Most significant and recent papers about the management of periprosthetic knee infection through a two-stage reimplantation protocol were carefully analysed and reviewed. Our personal experience, previously published, with two-stage-reimplantation protocol was also briefly reported. Two-stage reimplantation has been reported as the most successful method of treating periprosthetic knee infections. The strategy of using an antibiotic-loaded cement spacer and intravenous antibiotics with delayed exchange arthroplasty is actually considered the state-of-the-art, with a reported success rate of 88-96%. The two-stage protocol has been reported as a viable option also for patients with a periprosthetic knee infection by multidrug-resistant organisms. On the other hand, open debridement with polyethylene exchange and single-stage reimplantation have been reported effective only in selective case series involving acute infections by low-virulence organisms. The strategy that involves the use of cement spacer, intravenous antibiotic therapy, and successive revision total knee implantation is nowadays considered the gold standard for the management of the periprosthetic knee infection. This treatment is actually considered the first choice not only for chronic but also for acute infections, especially in the presence of resistant bacteria.

Management of Chronically Infected Total Knee Arthroplasty With Severe Bone Loss Using Static Spacers With Intramedullary Rods

BackgroundTwo-stage revision with static antibiotic spacers is the preferred treatment for chronically infected total knee arthroplasty (TKA) associated with severe bone loss. Intramedullary rods to reinforce static spacers have been described. On those, however, bacterial colonization may occur and hamper infection control. This study reports the microbiological findings on the spacer rods and the treatment outcome among these patients. MethodsWe reviewed 97 infected TKA with extensive bone loss treated with antibiotic-loaded cement spacers reinforced with intramedullary rods. Mean interim period with the spacer in situ was 9 weeks (range: 6-24 weeks). Intraoperative cultures and sonicated spacer rods were analyzed. Mean follow-up after TKA reimplantation was 41 months (range: 27-56 months). Treatment success was defined using the modified Delphi consensus criteria. ResultsTwenty-two patients (23%) had treatment failure, including 3 reinfections caused by the same organism, 9 reinfections caused by a different organism, 9 patients required interim spacer exchange, and 1 patient died in the early postoperative course. Sonication cultures of the spacer rods were positive in 2 cases (2%), and none of them failed. Host and limb status was significantly worse in patients who sustained reinfection. At the latest follow-up, all patients had a TKA in place, and 2 patients received chronic antibiotic suppression. ConclusionTwo-stage revision with the use of intramedullary rods is a safe and efficient treatment for chronically infected TKA with severe bone loss. Most reinfections grew different organisms compared with initial infection. Compromised hosts and extremities may be subjected to chronic antibiotic suppression.

Partial two-stage exchange at the site of periprosthetic hip joint infections.

In the past 10years an increasing number of studies about partial two-stage exchange arthroplasty in the management of periprosthetic hip infections have been published. The aim of the present work was to systematically review the current knowledge about this procedure, and critically verify the success as well as the complications of this treatment option. A literature search was performed through PubMed until June 2018. Search terms were "partial two stage hip" and "partial retention hip", and "retaining well fixed hip". A total of 7 studies reporting on a total of 80 patients could be identified. All studies had a level of evidence IV. The great majority of the studies reported on the isolated removal of the acetabular cup and placement of an antibiotic-loaded cement spacer head onto the retained, well-fixed stem. Most of the periprosthetic infections were caused by staphylococci. The infection eradication rate varied between 81.3 and 100% at a mean follow-up between 19 and 70months. Poor outcome was observed at the site of MRSA infections. The partial two-stage exchange arthroplasty appears to be a possible option in the management of PJI when one prosthetic component is well-fixed so that their removal might result in significant bone loss and compromise of fixation at the time of the later prosthesis reimplantation, and the causative organisms are not multiresistant. The small numbers published about this protocol does not allow for a generalization of application and should be only applied in highly selected patients. Future studies with larger collectives and longer follow-ups are welcome to evaluate the clinical success of this option and its possible role in the management of PJI.