Introduction. Knee arthrodesis is a useful limb salvage technique to maintain function in patients with complex and infected total knee arthroplasties (TKA). There are a number of commonly used external fixators, but no consensus on which of these are optimal. The aim of this study was to synthesise the current literature to guide clinical decision making and improve patient outcomes. We systematically review the literature to compare outcomes of external fixators in arthrodesis following infected TKA. Materials & Methods. A systematic review of the literature of primary research articles investigating the use of external fixators for knee arthrodesis after an infected TKA was conducted. Relevant articles were identified with a search strategy on online databases (EMBASE and Medline) and reviewed by two independent reviewers. Clinical outcome measures were independently extracted by two reviewers which included union rate, infection eradication rate, complication rate, time to fusion, and time in frame. Results. Circular frames were more likely to result in union compared to biplanar (OR 1.40 p=0.456) and monoplanar frames (OR 2.28 p=0.018). Infection recurrence was least likely in those treated by circular frames when compared to monoplanar (OR 0.12 p=0.005) and biplanar external fixators (0.41 P=0.331). Complication rates were highest in the circular fixator group, followed by the monoplanar fixator group and biplanar fixator group at 34%, 31% and 11% respectively. Conclusions. Analysis of the available literature suggests higher union and infection eradication rates with circular frames over the other two fixation methods despite a higher complication rate. There is a paucity in the literature and therefore, no firm conclusions can be drawn. Further research investigating the variations and biomechanical properties between different external fixation methods for knee arthrodesis is necessary. Further clarity in reporting and pooled data would be useful for future analysis

Aim. Prosthetic joint infections (PJI) after failed knee arthroplasty, especially in complicated courses with persisting or recurrent infections, may result in a considerable destruction of bone substance, the extensor apparatus and the surrounding soft tissue. In these cases reconstruction of a proper knee function may be impossible and the only solutions are: knee arthrodesis or above-the-knee amputation (AKA). However, both methods are associated with considerable functional deficits and high complication rates. The primary aim of the current study is to analyse the clinical course, outcome and complications in patients with knee arthrodesis and AKA after PJI and to compare these two methods in terms of the analysed parameters. Method. Patients treated with a knee arthrodesis or AKA after PJI in an 11-year time period were included in this study. Demographic data, comorbidities, infecting characteristics and operative procedures were recorded. Patients were seen in regular intervals and underwent physical and radiographic examination. Major complications such as: re-infection, implant-failure, revision surgeries or stump healing disorders were recorded. Functional outcome with use of the Lower-Extremity-Functional-Score was assessed and the patients reported general health status (SF-12-questionnaire) was recorded. Results. In total 87 patients with a knee arthrodesis and 32 patients with an AKA after PJI were included. Knee arthrodesis was performed in 81 patients with a modular system and in six cases with bone fusion. Re-arthrodesis had to be performed in 21 cases. Survival rate of knee arthrodesis was 86% after one year, 71% after five and 61% after ten years. Major complications such as recurrence of infection (n=16) implant loosening (n=12), implant failure (n=3) or per-implant fracture (n=5) occurred in 30% of the patients. In seven patients an amputation after failed arthrodesis had to be performed. In patients with AKA after PJI a similar complication rate of 34% (p=0.64) was seen. Recurrence of infection was diagnosed in nine patients and a re-amputation had to be performed in four cases. The final functional examination was assessed after a mean interval of 48 month and revealed comparably in both cohorts a comparable limitation of functionality (p=0.181) and a slightly worse physical quality of life after knee arthrodesis compared to patients with AKA (p=0.08). Conclusions. Knee arthrodesis or above the knee amputation after PJIshow similar functional limitations and comparably high complication rates. The patients have to be supervised by an interdisciplinary team to avoid complications and regain quality of life

Aim. Antibiotics have limited activity in the treatment of multidrug-resistant or chronic biofilm-associated infections, in particular when implants cannot be removed. Lytic bacteriophages can rapidly and selectively kill bacteria, and can be combined with antibiotics. However, clinical experience in patients with surgical infections is limited. We investigated the outcome and safety of local application of bacteriophages in addition to antimicrobial therapy. Method. 8 patients (2 female and 6 male) with complex orthopedic and cardiovascular infections were included, in whom standard treatment was not feasible or impossible. The treatment was performed in agreement with the Article 37 of the Declaration of Helsinki. Commercial or individually prepared bacteriophages were provided by ELIAVA Institute in Tbilisi, Georgia. Bacteriophages were applied during surgery and continued through drains placed during surgery three times per day for the following 5–14 days. Follow-up ranged from 1 to 28 months. Results. Median age was 57 years, range 33–75 years. Two patients were diagnosed with a persistent knee arthrodesis infection, one chronic periprosthetic joint infection (PJI), one cardiovascular implantable electronic device (CIED) infection and four patients with left ventricular assist device (LVAD) infection. The isolated pathogens were multi-drug-resistant Pseudomonas aeruginosa (n=3), methicillin-sensitive Staphylococcus aureus (n=4), methicillin-resistant Staphylococcus aureus (MRSA) (n=1) and methicillin-resistant Staphylococcus epidermidis (MRSE) (n=1). 4 infections were polymicrobial. 5 patients underwent surgical debridement with retention of the implant, 1 patient with PJI underwent the exchange of the prosthesis and one patient with LVAD infection was treated conservatively. All patients received intravenous and oral antibiotic therapy and local application of bacteriophages. At follow-up of 12 month, 5 patients were without signs or symptoms of infection, whereas in one patient with LVAD infection, a relapse was observed with emergence of phage-resistant Pseudomonas aeruginosa. In this patient, no surgical revision was performed. Conclusions. Bacteriophage therapy may represent a valid additional approach, when standard antimicrobial and surgical treatment is not possible or feasible, including in difficult-to-treat infections. In our case series, 5 of 6 patients were infection free after 1 year. Further studies need to address the optimal bacteriophage administration route, concentration, duration of treatment and combination with antimicrobials

Periprosthetic infection is a challenging complication of total knee arthroplasty (TKA) which reported incidence varies from 1 to 2% in primary TKA and 3–5% in revision TKA. Persistent infection of TKA may benefit from knee arthrodesis when all reconstruction options have failed. Knee arthrodesis also demonstrated better functional results and pain relief than other salvage procedures such as above-knee amputation. The purpose of this study was to analyze treatment results in patients who underwent knee arthrodesis following infected TKA. Retrospective study with review of the data of all patients treated in our department with knee arthrodesis for chronic infection of knee arthroplasty between 2009 and 2014. Clinical and radiographic data were evaluated as well as several variables: technique used, fusion rate, time to fusion, need for further arthrodesis and complications. Patients with less than 8 months of follow-up were excluded from this study. 46 patients were treated with knee arthrodesis in our department from 2009 to 2014 for chronic infection of total knee arthroplasty. The sample included 26 (57%) women and 20 (43%) men, median age of 70 years. In 45 patients, the technique used was compressive external fixation, while an intramedullary modular nail was used in 1 patient. Mean follow-up of these patients was 35 months (8–57). Primary knee fusion was obtained in 32 (70%) patients with a mean time to fusion of 5,8 months (4–9). 9 (20%) patients needed rearthrodesis and 7 (15%) ultimately achieved fusion. 33 (72%) patients underwent knee arthrodesis in a single surgical procedure, while 13 (28%) firstly removed knee arthroplasty and used a spacer before arthrodesis. Overall complication rate was 35%; 7 (15%) patients experienced persistent infection and 4 (9%) of these undergone above knee amputation. Treatment of septic total knee replacement is a surgical challenge. Compressive external fixation was the method of choice to perform knee arthrodesis following chronic infected TKA. Although complication rate was worrisome, overall fusion rate was satisfactory and this arthrodesis method can be safely performed in one stage

Knee arthrodesis is a potencial salvage procedure for limb preservation in patients with multiple failures of Total Knee Arthroplasty (TKA) with massive bone loss and extensor mechanism deficiency. The purpose of the study is to evaluate the outcome of bridging knee arthrodesis using a modular and non cemented intramedullary nail in patients with septic failure Total Knee Arthroplasty. Between 2005 and 2013 (9 years), 15 patients (13 female and 2 male) with mean age 71.1 years (range 41 to 85) were treated at our Institution with septic two- stage knee arthrodesis using a modular and non- cemented intramedullary nail after multiple failures of septic Total Knee Arthroplasty. Mean follow- up was 70.1 months (24 to 108 months) with a minimum follow- up of 24 months. We evaluated the erradication of infection clinically and with normalization of laboratory parameters (ESR and CRP), limb length discrepancies and complications (periimplant fractures, amputation rates, wound healing disturbances) and the subjective evaluation of the patients after knee arthrodesis. We reported 11 cases of resolution of the infection (73.3 %), with good tolerance of the implant and a mean limb length discrepancies of 15 mm. Of these, 8 patients had been monitored over 5 years without recurrence of the infection. The mean number of previous operations was 4.9 (range 2 to 9). Two patients (13.3 %) required multiples surgical debridements for uncontrolled sepsis and finally underwent knee amputation. Coagulase- negative Staphylococci (SCN) were the most commom pathogen (53.3 %) followed by polimicrobian infections (26.7 %). One patient continues suppressive antibiotic treatment and 1 patient was treated with a one- stage custom- made arthrodesis nail exchange. Bridging knee arthrodesis using a modular and non- cemented intramedullary nail is a salvage procedure with acceptable results in terms of erradication of infection after septic faliure Total Knee Arthroplasty with restoration of limb length discrepancy. Despite these satisfactory results it is not without serious complications such as knee amputation

Aim. Reconstruction of composite soft-tissue defects with extensor apparatus deficiency in patients with periprosthetic joint infection (PJI) of the knee is challenging. We present a single-centre multidisciplinary orthoplastic treatment concept based on a retrospective outcome analysis over 20 years. Method. One-hundred sixty-seven patients had PJI after total knee arthroplasty. Plastic surgical reconstruction of a concomitant perigenicular soft-tissue defect was indicated in 49 patients. Of these, seven presented with extensor apparatus deficiency. Results. One patient underwent primary arthrodesis and six patients underwent autologous reconstruction of the extensor apparatus. The principle to reconstruct missing tissue ‘like with like’ was thereby favoured: Two patients with a wide soft-tissue defect received a free anterolateral thigh flap with fascia lata; one patient with a smaller soft-tissue defect received a free sensate, extended lateral arm flap with triceps tendon; and three patients received a pedicled medial sural artery perforator gastrocnemius flap, of which one with Achilles tendon. Despite good functional results 1 year later, long-term follow-up revealed that two patients had to undergo knee arthrodesis because of recurrent infection and one patient was lost to follow-up. In parts, results have been published under doi: 10.7150/jbji.47018. Conclusions. A treatment concept and its rationale, based on a single-centre experience, is presented. It differentiates between various types of soft-tissue defects and shows reconstructive options following the concept to reconstruct ‘like with like’. Despite good results 1 year postoperatively, PJI of the knee with extensor apparatus deficiency remains a dreaded combination with a poor long-term outcome

Aim. External fixator knee arthrodesis is a salvage procedure mainly used in cases of end-stage infected total knee replacement (iTKR). A stable fixation combined with bone-ends compression is basic to achieve knee fusion in such a scenario but providing enough stability can be challenging in the presence of severe bone loss after multiple previous procedures. Compared with monoplanar configuration, a biplanar frame achieves improved coronal stiffness, while providing the advantages of good access to the wound and allowance of early ambulation. Our primary hypothesis stated that a biplanar frame would achieve higher and quicker fusion rate than a monolateral configuration. Method. We conducted a retrospective cohort study examining patients managed with biplanar external fixator knee fusion due to non-revisable iTKR between 2014 and 2018. We compared this group of patients with a historical cohort-control patient who had been previously published by our unit in 2013, since we switched from a monoplanar to a biplanar configuration for the management of this kind of complex end-stage iTKR. Primary end-points were fusion rate, time to achieve bone fusion and infection eradication rate. Limb-length discrepancy, pain level, patient satisfaction, and health-related quality of life were also evaluated. Results. A total of 29 cases were finally included; 8 patients were managed with a bilateral external fixator and 21 patients were managed with a monoplanar external fixator. In the biplanar configuration group, infection was eradicated in 100% of the patients, and fusion was achieved in all cases after 5.24 months on average. In comparison, in the monolateral configuration group, infection was eradicated in 18 (86%) out of 21, whereas fusion was achieved in 17 (81%) of the patients after a mean of 10.3 months (range, 4–16). Such difference was statistically significant (p<0.05). In both groups, postoperative pain was mild (VAS score 2,25 and 3,4, respectively) and patients expressed a high degree of satisfaction once fusion was achieved. Conclusions. External fixation knee fusion is a useful limb-salvage procedure in end-stage cases of knee PJI. According to our data, the use of a biplanar configuration allows us to reduce in half (10.3 vs 5.2 months, p<0.05) the time needed to achieve the solid bone fusion in such a complex scenario. In this cohort of previously multi-operated patients, the satisfaction is high, and the level of pain is low if a solid bone fusion free of infection is achieved

The purpose of the following study was to present the general strategy for preserving the lower extremity by knee arthrodesis and to analyze the outcome of knee arthrodeses performed by a special modular system. Between 2009 and 2014 35 knee arthrodeses were performed. 23 patients were male, 12 female. The average age was 66 years (42 to 83 years). The patients underwent an average of 6 operations because of infected knee arthroplasties previous to the knee arthrodesis. The main pathogen was S. epidermidis followed by MRSA. The arthrodeses system included a non cemented femoral and tibial stem (press fit application plus two static locking screws). These were connected by a special stem to stem clamp. Immediate postoperative full weight-bearing was possible in 32 of 35 patients. We saw 4 recurrent infections (all connected to the patients, who did not show a full weight bearing after knee arthrodesis). In two cases re-revision surgery was successful and lead to a sufficient re-arthrodesis. In two cases above-knee-amputation was necessary. Peri-implant fractures were detected in 3 cases. All of them could be cured by changing the arthrodesis stem and to a longer one bridging the fracture. In one case a stem loosening was seen. This was as well addressed by the use of a longer stem. Knee arthrodesis by a modular non cemented system is a god alternative in order to preserve the weight-bearing lower extremity. The complication rate is rather high due to the fact, that this procedure presents the final alternative to do so in patients, who are in extremis in terms of a long lasting aggressive peri-arthroplasty infection the lead to massive destruction of the soft tissue around the knee and a significant loss of function

Sepsis following total knee replacement (TKR) is a disastrous complication. The knee arthrodesis comes as the final solution to solve the chronic infection after multiple failed surgeries. Our objective was to review these procedures performed in our institution for the past 20 years. We present a retrospective study with 5 cases of severe unsolved knee infection after TKR, who have been finally submitted to knee arthrodesis performed between 1993 and 2008. The patients are 4 males and 1 female, with a mean age of 62 years (ranging from 55 to 74 years) at the time of surgery. They presented MRSA infection (3 cases), P aeruginosa infection (1 case) and Mycobacterium tuberculosis (1 case). The average follow up was 25 months (between 12–48 months). The Visual Analogic Scale (VAS) value was registered. The mean number of surgeries before the arthrodesis was 3,6. In 4 of the 5 cases the surgeon used an external fixator to achieve the fusion. In the other patient, an intramedullary nail was used. The arthrodesis was performed in a single-time surgery in every patient. All cases achieved knee fusion and the mean time of consolidation was 5,1 months, with the longest being 8 months until fusion. No bone graft was used in any of these cases, and the mean size of leg length discrepancy was 2,8 cm. The average VAS was 3,6. In one patient with an external fixator there was a relapse of the infection (MRSA infection), but with adequate antibiotic therapy (vancomycin) ended up to resolve. There are no records of any other complication. The knee arthrodesis appears as last but useful resort in extreme cases of relapse infection after a TKR and multiple unsuccessful surgeries. Although it comprises an elevated level of morbidity, it also seems to allow to heal difficult and multi resistant infections and with few complications

Aims. To evaluate the place of the massive prostheses in the most complex periprosthetic infections cases (PJis). Method. Between 2011 and 2017, 516 hip and knee revisions for periprosthetic infections had been performed in our hospital by the same senior surgeon. We report a prospective series of 58 patients treated between 2011 and the end of 2017. 26 males and 32 females with on average 69,4 years old (38–86). Infection involved TKA in 39 cases (26 TKA revisions, 11 primary TKA), THA in 18 cases (10 revisions, 7 primary THA), a femoral pseudoarthrosis with posttraumatic gonarthrosis in one case and a septic humeral pseudoarthrosis in one case. We used one stage procedures in 38 cases (14 hips, 23 knees, 1 shoulder) and 20 two stages surgeries (16 knees and 4 hips). Additional technics used with massive prostheses, all for TKA PJis: 4 massive extensor systemallografts performed two times in a one stage procedure, two local flaps (medial gastronecmienmuscle). Two perioperative hyperbaric procedures used to limit the risks of wound complications. Results. The average follow-up is 38 months (12–62 months). The rate of sucess to treat the infection at this follow-up is 89,7 %. We report our feedback of the different massive components uses and the qualities/defaults we noted. The most frequent complication was skin events like wound swelling and delayed cicatrisations in 13 cases. 3 cases of one stages needed a complementary debridement in the three weeks after the surgery with always a good local and infectious evolution. This series report 5 failures of two stages TKA revisions. In 4 cases, the initial local soft tissues conditions were compromised. Conclusions. The use of massive prostheses to treat PJIs is a good option for the complex cases. It can be a good alternative of knee arthrodesis. These components must be used, preferentially for oldest patients, in cases of extreme bone loss or extensed osteitis to secure the bone debridement and the quality of the reconstruction. In our series, the one stage procedure is a validated option even by using complementary technics as bone allografts, extensor system allografts or flaps. The two stages procedure is a secondary option, particularly when softtissues status is compromised before or after the debridement, and mostly for the knees

Arthrodesis. Today, knee arthrodesis is most commonly performed for cases of chronic sepsis after total knee arthroplasty in patients who are not candidates for reimplantation. This is typically a host in whom the risk of recurrent infection is high, especially when extensor mechanism problems such as patellar tendon rupture is present. Local and systemic host factors place the patient at this high risk for failure of reimplantation. Local factors include chronic lymphedema, major vessel disease, venous stasis, extensive scarring and radiation fibrosis. Systemic problems include malnutrition, malignancy, extremes of age, hepatic or renal failure, diabetes mellitus and alcohol abuse. Also, at least in one study, patients who fail one two-stage reimplantation have at least a 50% change for recurrence the second time. Methods of knee arthrodesis include external fixation, single or double plate fixation and intramedullary nailing either monolithic or modular. External fixation can be performed as a single procedure. With external ring fixators leg lengthening has been described. Plate and nailing procedures are commonly performed after the infection is eradicated. If infection recurs but fusion has occurred, removal of a modular nail may be difficult although techniques have been described. Fusion rates of 85% to 100% have been reported with the newer techniques and fusion rates are usually correlated with the amount of bone loss after removal of the prosthesis. Optimal position of fusion is slight anatomic valgus and slight flexion. Placing a bowed intramedullary nail with the bow anteromedially can facilitate this alignment. One study comparing arthrodesis after failed knee arthroplasty with primary total knee replacement found nearly identical Short-Form 36 scores. Physical mobility was better with knee arthroplasty but pain control was better with arthrodesis. Resection Arthroplasty. Indication: Low demand patient with comorbidities. Results: Falahee et al.; 28 knees;15 patients walked independently; Most severely disabled more satisfied. Less disabled least satisfied. Amputation - Above the Knee Amputations after TKA (Sierra et al). Prevalence: 0.36% (all causes – most common was peripheral vascular disease), 0.14% (for causes related to TKA: infection, periprosthetic fracture, pain, bone loss, vascular complication). Results: 25 amputations for causes related to TKA; Avg 8.6 years after TKA. Complications: deep infection 5, superficial infection 1, skin necrosis 1, perioperative death 1. 9 of 25 fitted with above knee prosthesis; Only 5 were walking even to limited degree with prosthesis

Aim. Knee arthrodesis (KA) and above knee amputation (AKA) have been used for salvage of failed total knee arthroplasty (TKA) in the setting of periprosthetic joint infection (PJI). The factors that lead to a failed fusion and progression to AKA are not well understood. The purpose of our study was to determine factors associated with failure of a staged fusion for PJI and predictive of progression to AKA. Method. We retrospectively reviewed a single-surgeon series of failed TKA for PJI treated with two-stage KA between 2000 and 2016 with minimum 2-year follow-up. Patient demographics, comorbidities, surgical history, tissue compromise, and radiographic data were recorded. Outcomes were additional surgery, delayed union, Visual Analog Pain scale (VAS) and Western Ontario and McMaster Activity score (WOMAC). No power analysis was performed for this retrospective study. Medians are reported as data were not normally distributed. Results. Fifty-one knees underwent fusion with median follow-up of 7 years (interquartile range (IQR) of 2–18 years). Median age was 71 years old (IQR 47 – 98), with a M:F ratio of 23:28. Median BMI was 34.3 kg/m2 (IQR 17.9–61). Infection was eradicated in 47 knees (92.2%); 24 knees (47.0%) required no additional surgery. 41 patients (83.6%) remained ambulatory after knee fusion, with 21% of these patients (10 total) requiring no ambulatory assistive device. Median VAS following arthrodesis was 4.6 (range 0–10). Median WOMAC was 36.2 (range 9–86). Three TKAs (5.9%) underwent AKA for overwhelming infection. Predictors of AKA were chronic kidney disease (OR 4.0, 95% CI 0.6–26.8), peripheral vascular disease (OR 3.5, 95% CI 0.3–44.7), AORI III bone loss (OR 2.6, 95% CI 0.4–35.2), instability (OR 2.2, 95% CI 0.2–15.9), and immunosuppression (OR 1.1, 95% CI 0.1–7.8). Tobacco use (OR 8.6, 95%CI 2.4–31.4), BMI>25 (OR 3.8, 95% CI 0.43–32.5) and instability prior to arthrodesis (OR 2.51, 95% CI 0.77–8.21) were associated with non-union. All other risk factors (gender, diabetes mellitus, chronic kidney disease, peripheral vascular disease, massive bone stock loss, and immunosuppression) were not associated with arthrodesis failure. Conclusions. Staged KA for PJI in severely compromised hosts provides a functional limb free of infection and rarely results in conversion to AKA. Given our small sample size, ability to establish statistical significance of predictive factors for AKA after PJI was limited, but CKD, peripheral vascular disease, AORI III bone loss, instability, and immunosuppression trended towards significance as predictors of failure of KA after PJI predisposing to AKA

Full-thickness burns around the knee can involve the extensor mechanism. The gastrocnemius flap is well described for soft tissue reconstruction around the knee. We describe a method where a Whichita Fusion Nail¯ knee arthrodesis, combined with a medial gastrocnemius muscle flap was used to salvage the knee and preserve the lower leg following a full-thickness contact burn. The gastrocnemius flap for wound coverage of an open knee joint was originally described in 1970 and remains the workhorse for soft tissue knee reconstruction. There are a number of local alternatives including the vastus lateralis, medialis and sartorius flap; and perforator flaps such as the medial sural artery perforator island flap and islanded posterior calf perforator flap, however many of these are unsuitable for larger defects. Full-thickness burns around the knee can put the extensor mechanism at risk and subsequent rupture is a possible consequence. The gastrocnemius flap has been used to cover a medial knee defect with exposed joint cavity following a burn and also been used in post burn contracture release around the knee. The primary indication for Wichita fusion nail is a failed total knee replacement. It allows intramedullary stabilization with compression at the arthrodesis site to stimulate bone union. With fusion rates reported up to 100% and low complication rates as compared to other methods of fusion, the technique has a useful role in limb salvage type procedures. While use of the gastrocnemius flap in knee burns has been described before we believe this is the first time that this combination of techniques, namely knee arthrodesis with soft tissue reconstruction using a gastrocnemius flap, has been reported. Combining these procedures with a multidisciplinary approach provides a useful alternative leading to limb salvage and avoiding the need for an above knee amputation when extensor reconstruction is not possible

Introduction. Infection following total knee arthroplasty (TKA) is a catastrophic complication. In the United States, for chronic, first time infected TKA, the gold standard remains a 2-stage reimplantation (2SR) procedure, with reported success rates approaching 90%. However, there is a lack of consensus on the treatment of subsequent reinfections. Question. The purpose of this study was to use published data on infected TKA to develop a decision tree analysis to determine the treatment method likely to yield the highest quality of life for a patient following a failed 2SR. Methods. We performed a systematic review of the English literature to determine the expected success rates and functional outcomes of a 2SR procedure, chronic suppression, arthrodesis, and amputation for treatment of infected TKA. Utility and disutility tolls were derived for each treatment option and a decision tree analysis (Figure) was conducted using TreeAgePro 2012 (Williamstown, Massachussetts). The efficacy of each of the treatment nodes was calculated based on prior published methods for each study. These values were subsequently varied to perform a sensitivity analysis. Results. Initial search yielded 204 papers; 18 studies met inclusion criteria. The composite success rate for 2SR was 79.1% (range 33.3%–100%). The utility and disutility toll (cost for treatment) for 2SR were 0.473 and 0.20, respectively; the toll for undergoing chronic suppression was set at 0.05; the utility for arthrodesis was 0.740 and for amputation 0.423. In all iterations of the decision tree analysis with varying sensitivities, knee arthrodesis emerged as the treatment most likely to yield the highest expected quality of life following a failed 2SR for infection. Discussion. Our study found that 2SR is successful at a lower rate than that traditionally cited. We also describe, for the first time, the typical rate at which salvage procedures are utilized after a failed 2SR. Finally, our study suggests that a successful fusion optimizes the patient's expected quality of life after a first failed 2SR. This outcome held up through sensitivity analysis. Conclusion. Based on best available evidence, knee arthrodesis should be strongly considered as the treatment of choice for patients who have persistent infected TKA following a failed 2-stage reimplantation procedure

Background. Clinical and anatomical complications from total knee replacement (TKR) procedures are debilitating, and include weakness, damage, and the loss of native anatomy. As the annual number of primary TKR surgeries in the United States has continued to rise, to a projected 3.48 million in 2030, there has been a concomitant rise in revision surgery. Damage to or loss of native knee anatomy as a result of TKR revision can leave the patient with irreversible knee dysfunction, which is a contra-indication for most TKR systems on the market. This leaves the multi-revision patient with limited medical options. Complete fusion of the joint, known as arthrodesis, is indicated in some cases. Arthrodesis is also commonly indicated for traumatic injury, bone loss, quadriceps extensor mechanism damage, and osteosarcoma. While this treatment may resolve pain and allow a patient to walk, the inability to flex the knee results in considerable functional complications. Patients with arthrodesis are unable to drive, sit in close-quarter spaces, or engage in a significant number of activities of daily living. Product Statement. The authors have developed and patented the Engage Knee System, a novel TKR system that allows a patient to lock and unlock the knee joint by means of a handheld, non-invasive device. An internal locking mechanism is constructed of materials that have been used in orthopedic joint replacements that have been approved through the FDA 510(k) process. A lightweight, handheld magnetic device is used to actuate the locking mechanism. No percutaneous components are required or present. This device allows a patient to lock their knee joint in full extension to ambulate with the functional equivalence of an arthrodesis, but allows a patient to unlock the device and bend the knee to engage in passive activities that would be otherwise difficult or impossible. The IP portfolio for this technology is owned by Clemson University, and they are seeking a partner/licensee to pursue further technology development and validation. Methods. A literature review of knee arthrodesis incidence and prevalence has been published by the inventors. Three- dimensional gait analysis was used to characterize rigid-knee gait kinematics and kinetics to verify potential implant design loads. Multiple physical prototypes of the design were created and implanted in Sawbones synthetic knee models, and a final prototype using industry-standard arthroplasty materials was contract-manufactured. Results. The Engage system is capable of locking and unlocking in full extension with the use of a non-invasive hand-held device. The device will support the loading patterns and magnitudes during stiff knee gait, as estimated through gait analysis and musculoskeletal modeling, when it is locked in full extension. Conclusion. The Engage Knee System bridges the gulf between existing treatments, and addresses not only patients who would otherwise undergo arthrodesis, but also patients who have avoided treatment or who currently undergo high-risk revision procedures. The device is also a viable option for arthrodesis takedown, providing patients who have already undergone arthrodesis a means of regaining knee flexion

Aim. For which patients is bone defect reconstruction with the Masquelet-technique after the treatment of osteomyelitis suitable and which results did we have. Methods. From 11/2011 to 4/2018 we treated 112 Patients (36f, 76m) with bone defects up 150mm after septic complications with the Masquelet-technique. We had infected-non-unions of upper and lower extremity, chronic osteomyelitis, infected knee-arthrodesis and knee- and ankle-joint-empyema. On average the patients were 52 (10–82) years old. The mean bone defect size was 48 mm (15–150). Most of our patients came from other hospitals, where they had up to 20 (mean 5.1) operations caused by the infection. Time before transfer in our hospital was on average 7,1 months (0,5–48). 77 patients received free (25) or local (52) flaps because of soft tissue-defects. 58 patients suffered a polytrauma. In 23 cases femur, in 4 cases a knee arthrodesis, in 68 cases tibia, in 1 case foot, 6 times ankle-joint arthrodesis, in 6 cases humerus, in 4 cases forearm were infected resulting in bone defects,. In most cases the indication for the Masquelet-technique was low-/incompliance due to higher grade of brain injury and polytrauma followed by difficult soft tissue conditions and problems with segmenttransport. In 2/3 positive microbial detection succeeded at the first operation. Mainly we found difficult to treat bacteria. After treating the infection with radical sequestrectomy, removal of foreign bodies and filling the defect with antibiotic loaded cementspacer and external fixation we removed the spacer in common 6–8 weeks later and filled the defect with autologeous bone graft. Most of the patients needed an internal fixation after removing of the fixex. All patients were examined clinically and radiologically every 4–6 weeks in our outpatient department until full weight bearing, later every 3 Months. Results. in 93 of 112 cases the infection was clinically treated successful. 48 patients are allowed full weight bearing (45 with secondary internal plates). There were 18 recurrences of infection, 3 patients underwent lower limb amputation. Conclusions. For patients with low-/incompliance for various reasons and for those with difficult soft tissue conditions following flaps the masquelet technique is a valuable alternative to normal bone graft or segmenttransport. The stiffness of the new masquelet-bone as a rod seems a problem and internal fixation is necessary

Aim. Optimal strategies for surgical and antimicrobial management of Candida periprosthetic joint infections (PJI) are unclear. We present a retrospective case series of patients diagnosed with PJI caused by Candida spp. Method. Patients treated at our institution with Candida PJI from 01/2017 to 04/2018 were retrospectively included with isolation of Candida spp. in synovial fluid, intraoperative tissue or sonication fluid culture. PJI was defined by the proposed European Bone and Joint Infection Society (EBJIS) criteria. Treatment failure was defined as relapse or persistence of infection. Results. We included 9 patients (4 men and 5 women, mean age 75 years) involving 4 knee and 5 hip joint prosthesis. Risk factors for Candida PJI were prior PJI (n=4), diabetes mellitus (n=3), chronic kidney disease (n=3), obesity (n=3), negative-pressure wound therapy (n=3), rheumatoid arthritis (n=1) and chronic decubitus (n=1). Two patients had no risk factors for Candida PJI identified. Infection was acquired postoperatively (n=7), hematogenously (n=1) or contiguously through communicating vesico-articular sinus (n=1). The causative pathogen was C. albicans in 5, C. parapsilosis in 3, C. tropicalis in 1 patient, isolated from periprosthetic tissue samples (n=7), sonication fluid (n=3) and blood cultures (n=2); bacterial co-pathogens were isolated in 8 patients. Histopathological analysis revealed low-grade inflammation in all 6 patients, in whom it was performed. All patients were treated with oral fluconazole for 3 months, two initially received intravenous caspofungin and three received suppression with oral fluconazole for additional 9 months (total treatment 12 months). Liposomal amphotericin B (300–700 mg per 40 g bone cement) was admixed to spacer cement in 3 patients. Debridement and prosthesis retention was performed in one patient with tumor prosthesis after bone resection due to osteochondrosarcoma. In the remaining 8 patients the prosthesis was removed, with one-stage reimplantation in 1 patient and two-stage reimplantation in 3 patients (after 6 weeks, 3 months and 7 months); two patients are currently awaiting reimplantation, one died due to reason not related to PJI and another underwent knee arthrodesis. Among 5 patients with prosthesis in place, relapse occurred in one patient with prosthesis retention. Another patient experienced new PJI of the exchanged prosthesis caused by Staphylococcus aureus. Conclusions. All Candida PJI presented as chronic infection with low-grade inflammation. Treatment with prostheses retention failed, whereas in 4 patients who underwent two-stage exchange and long-term antifungal suppression, no relapse or persistence of infection was observed. All patients received oral fluconazole for ≥3 months

Purpose. Failure resulting from a recurrent infection in total knee arthroplasty (TKA) is a challenging problem. Knee arthrodesis is one treatment option, however fusion is not always successful, as there is huge bone defect. The authors reports a new arthrodesis technique that uses a bundle of flexible intramedullary rods and an antibiotic-loaded cement spacer. Methods. There were 13 cases of arthrodesis due to recurrent periprosthetic joint infection, which were performed by the first author (WS Cho) at Asan Medical Center in Seoul from 2005 to 2014. All previous prosthetic components were removed and cement was thoroughly excised using a small osteotome. Two stage operation was done in most of cases. After thorough debridement, antibiotics loaded cement was inserted in first stage, flexible intramedullary rods were inserted retrogradely in the femoral side with the knee in flexion under fluoroscopy guidance. After filling the femoral intramedullary canal, the rods were then driven back securely into the tibial medullary canal. We aimed for as much rod length as possible to maximize stability. After 6 weeks of first stage operation, the rods of the femoral and tibial sides were arranged such that they overlapped and interdigitated to maximize mechanical strength, maintain the limb length and keep the rotational alignment. The interdigitating rod ends were tightly fixed using two (or three) cerclage wires. Antibiotic-loaded cement was filled into the knee joint space so that the cement is fit to the irregular contour of the femur and tibia, which was resulted from the severe bone loss. Postoperatively, patients were allowed to weight bear as tolerated. Results. The procedure was successful in every cases with no evidence of rod or cement failure at least 1 year follow up. Also there was no recurrence of infection. Conclusion. Although this simple method was not for bony union, the authors could achieve stable knee joint without recurrence of infection

Aim & introduction. Infected knee with bone defect resulting from failed total knee arthroplasty (TKA) or destruction of native joint can necessitate restoration of segmental defect and arthrodesis for therapy of infection and maintenance of walking ability. In segmental knee defect external fixators or KAFO are not suitable, not comfortable and poor tolerated by elderly patients. Both custom-made Femoro-Tibial Nail (FTN) combined with acrylic cement spacer and Knee Arthrodesis Nail System (KANS) offer maintenance of supportive function of extremity and avoidance of leg length discrepance after removal of TKA. Method. The group consists of 13 patients. In 12 cases knee arthrodesis have been performed due to infection with bone defect after removal of infected TKA, and in 1case due to inflammatory destruction of native knee joint. In 7 cases FTN with ALAC spacer and in 6 cases KANS (5 cases Orthopedic Salvage System-OSS; 1 case Link KANS) was used. In cases treated with FTN the gap between distal femur and proximal tibia was filled with hand-made acrylic cement spacer loaded with selected antibiotic (2g per 40 g cement) so that the spacer finally gained cylindrical shape. Results. Stable knee was noted after 7 years in 4 of 7 knees treated with FTN with ALAC spacer and after 2 years in 6 of 6 after KANS. Infection free knee was gained after 7 years in 4 of 7 cases treated with FTN with ALAC spacer and after 2 years in 5 of 6 cases treated with KANS. Amputation was necessary after 6 years in 3 of 7 cases treated with FTN with ALAC spacer and after 2 years in none case treated with KANS. Complications occurred in 2 cases after FTN with ALAC spacer (1x: FTN breackage, 1x: stress fracture of femoral neck) and in 1 case after KANS (OSS implant failure). Replacement of FTN nail and cement spacer in 1 case and respectively revision of OSS KANS in 1 cases was performed. Conclusions. Compared with the KANS, custom-made FTN combined with ALAC spacer proved to be effective up to 6 years, but shoved higher rate of complications and amputations after 6 years. It can be considered as a temporary low-cost salvage procedure for infected TKA with segmental bone defect as 1. st. stage in two-stage arthrodesis for infected knee prosthesis

Aims

The timing of when to remove a circular frame is crucial; early removal results in refracture or deformity, while late removal increases the patient morbidity and delay in return to work. This study was designed to assess the effectiveness of a staged reloading protocol. We report the incidence of mechanical failure following both single-stage and two stage reloading protocols and analyze the associated risk factors.