Tibiocalcaneal arthrodesis using the Ilizarov fixator in compromised hosts: an analysis of 19 patients.

INTRODUCTION: Salvage of joint destruction of the tibiotalar and subtalar joint with necrosis or infection of the talus in compromised hosts is a challenging problem. In these cases, tibiocalcaneal arthrodesis using the Ilizarov external fixator represents a possible alternative to amputation. This retrospective study presents the results and complications of this salvage procedure. MATERIALS AND METHODS: Between 2005 and 2015, 19 patients were treated with tibiocalcaneal arthrodesis using the Ilizarov external fixator. Ten patients received tibiocalcaneal arthrodesis due to an acute or chronic infection with joint destruction. The other nine patients presented posttraumatic necrosis of the talus or Charcot arthropathy. In addition to demographic data, the time spent in the fixator, the major and minor complications and the endpoint of the consolidation were evaluated retrospectively. Furthermore, clinical outcomes were measured using the modified American Orthopedic Foot and Ankle Society (AOFAS) score. RESULTS: The average time spent in the fixator was 22 (range 14-34) weeks. The average follow-up in 17 patients was 116 (range 4-542) weeks. Two patients were lost to follow-up. Complete osseous consolidation was achieved in 14 out of 19 patients. One patient presented partial consolidation, and in four patients, pseudarthrosis could be detected. The mean modified AOFAS score at the final follow-up was 53 out of 86 possible points. CONCLUSION: Tibiocalcaneal arthrodesis using the Ilizarov fixator is a possible salvage procedure even in compromised hosts. However, the healing rates are below the rates reported in the literature for tibiotalar arthrodesis in comparable clinical situations.

Simultaneous septic arthrodesis of the tibiotalar and subtalar joints with the Ilizarov external fixator-an analysis of 13 patients.

PURPOSE: Treatment of joint destruction of the tibiotalar and subtalar joints caused by acute or chronic infections in compromised hosts is a challenging problem. In these cases, simultaneous septic arthrodesis with the use of the Ilizarov external fixator represents a possible alternative to amputation. This case series presents the results and complications of patients with acute or chronic infection of the tibiotalar and subtalar joints. METHODS: Between 2005 and 2015, 13 patients with acute or chronic infections were treated by simultaneous single-stage debridement/arthrodesis of the tibiotalar and subtalar joints. In seven patients, there was a florid infection with fistula formation and soft tissue defects, and in six patients, there was chronic osteomyelitis with closed soft tissue. In addition to the demographic data, the time spent in the fixator, the major and minor complications and the endpoint of consolidation were reviewed. RESULTS: The mean time spent in the fixator was 18 (min 15, max 26) weeks. The mean follow-up time for nine patients was 100 (min 3, max 341) weeks. Complete osseous consolidation of both the tibiotalar and subtalar joints was achieved in 10 patients (77%). In three (23%) patients, there was complete consolidation of one of the joints and partial consolidation of the other joint. CONCLUSION: The Ilizarov external fixator allows for simultaneous arthrodesis of the tibiotalar and subtalar joints in septic joint destruction. However, the healing rates are below the rates reported in the literature for isolated tibiotalar or tibiocalcaneal arthrodesis in comparable clinical situations.

Accuracy of radiographic measurement techniques for the Taylor spatial frame mounting parameters.

AIM: The correction accuracy of the Taylor Spatial Frame (TSF) fixator depends considerably on the precise determination of the mounting parameters (MP). Incorrect parameters result in secondary deformities that require subsequent corrections. Different techniques have been described to improve the precision of MP measurement, although exact calculation is reportedly impossible radiologically. The aim of this study was to investigate the accuracy of intraoperative and postoperative radiographic measurement methods compared to direct MP measurement from TSF bone mounting. METHODS: A tibial Sawbone® model was established with different origins and reference ring positions. First, reference MPs for each origin were measured directly on the frame and bone using a calibrated, digital vernier calliper. In total 150 MPs measured with three different radiographic measurement techniques were compared to the reference MPs: digital radiographic measurements were performed using soft-copy PACS images without (method A) and with (method B) calibration and calibrated image intensifier images (method C). RESULTS: MPs measured from a non-calibrated X-ray image (method A) showed the highest variance compared to the reference MPs. A greater distance between the origin and the reference ring corresponded to less accurate MP measurements with method A. However, the MPs measured from calibrated X-ray images (method B) and calibrated image intensifier images (method C) were intercomparable (p = 0.226) and showed only minor differences compared to the reference values but significant differences to method A (p < 0,001). CONCLUSION: The results demonstrate that MPs can be accurately measured with radiographic techniques when using calibration markers and a software calibration tool, thus minimizing the source of error and improving the quality of correction.

Poor outcome of octogenarians admitted to ICU due to periprosthetic joint infections: a retrospective cohort study.

BACKGROUND: Even though surgical techniques and implants have evolved, periprosthetic joint infection (PJI) remains a serious complication leading to poor postoperative outcome and a high mortality. The literature is lacking in studies reporting the mortality of very elderly patients with periprosthetic joint infections, especially in cases when an intensive care unit (ICU) treatment was necessary. We therefore present the first study analyzing patients with an age 80 and higher suffering from a periprosthetic joint infection who had to be admitted to the ICU. METHODS: All patients aged 80 and higher who suffered from a PJI (acute and chronic) after THR or TKR and who have been admitted to the ICU have been included in this retrospective, observational, single-center study. RESULTS: A total of 57 patients met the inclusion criteria. The cohort consisted of 24 males and 33 females with a mean age of 84.49 (± 4.0) years. The mean SAPS II score was 27.05 (± 15.7), the mean CCI was 3.35 (± 2.28) and the most patient had an ASA score of 3 or higher. The PJI was located at the hip in 71.9% or at the knee in 24.6%. Two patients (3.5%) suffered from a PJI at both locations. Sixteen patients did not survive the ICU stay. Non-survivors showed significantly higher CCI (4.94 vs. 2.73; p = 0.02), higher SAPS II score (34.06 vs. 24.32; p = 0.03), significant more patients who underwent an invasive ventilation (132.7 vs. 28.1; p = 0.006) and significantly more patients who needed RRT (4.9% vs. 50%; p < 0.001). In multivariate analysis, RRT (odds ratio (OR) 15.4, CI 1.69-140.85; p = 0.015), invasive ventilation (OR 9.6, CI 1.28-71.9; p = 0.028) and CCI (OR 1.5, CI 1.004-2.12; p = 0.048) were independent risk factors for mortality. CONCLUSION: Very elderly patients with PJI who needs to be admitted to the ICU are at risk to suffer from a poor outcome. Several risk factors including a chronic infection, high SAPS II Score, high CCI, invasive ventilation and RRT might be associated with a poor outcome.

Persistent Fistula for Treatment of a Failed Periprosthetic Joint Infection: Relic From the Past or a Viable Salvage Procedure?

BACKGROUND: New treatment algorithms for periprosthetic joint infections (PJIs) show high success rates in achieving permanent infection eradication with some degree of failure. Different salvage procedures are described, but there is no evidence for persistent fistula (PF). The purpose of this study was to analyze PF as a salvage procedure in patients with therapy-resistant PJIs. METHODS: This retrospective analysis included all patients treated with PF (2005-2018) in a maximum care center with PJI (knee or hip). The baseline parameters (age, sex, BMI) and other data (number of surgeries, pathogen spectrum, American Society of Anesthesiologists classification) were recorded. The function was documented using the Harris Hip Score, the Knee Society Score, and the quality of life using the SF-36 Health Survey. RESULTS: A total of 159 patients were included (80 ± 12 years) and subdivided into four groups: hip (n = 66), knee (n = 13), Girdlestone resection arthroplasty (n = 50), knee arthrodesis (n = 27). Patients stayed 111 ± 87 days in the hospital, underwent six operations and three revisions after establishing PF. The mean American Society of Anesthesiologists score was 2.7. The BMI was 31 ± 3 kg/m2 (P = .1). The follow-up was 2.8 ± 0.5 years including 27 patients. The Harris Hip Score and Knee Society Score were 38 and 34, respectively. SF-36 showed no significant difference. CONCLUSION: The study showed poor outcomes regarding quality of life and the function of the infected joint. Therefore, the indication for establishing a PF in the treatment of PJI must be assessed very critically. PF is only an option for multimorbid patients with a limited life expectancy.

Risk factors and outcome of patients with periprosthetic joint infection admitted to intensive care unit.

INTRODUCTION: Prosthetic joint infection (PJI) is a severe complication after total joint replacement surgery. The current study analyzes the outcome and mortality of patients admitted to an intensive care unit following PJI. METHODS: Retrospective analysis of all patients treated between 2012 and 2016 due to PJI in the surgical intensive care unit of a university hospital. RESULTS: A total of 124 patients were included. The mean age was 75 ± 11 years. Of those 124 patients, 85 patients (68.5%) suffered a prosthetic infection of the hip, 33 patients (27.3%) of the knee, six patients (4.8%) of hip and knee. 52 patients were male (40.9%). The assessed mean Simplified Acute Physiology Score II (SAPSII) was 29.6 ± 5.9. The mortality rate was 21% (26/124). Of surviving patients, 53.1% were discharged home, 25.5% were transferred to a nursing home, and 21.4% were transferred to a geriatric rehabilitation center. Comparing survivors to non-survivors, the non-survivor group showed a higher incidence of renal replacement therapy (46.1 vs 3.0%; p < 0.01), higher SAPSII on admission (35.7 vs. 29.0; p = 0.01) and higher Charlson Comorbidity Indices (CCI) (5.5 vs. 2.82; p < 0.01). The multivariate regression identified CCI (odds ratio 1.49; p < 0.01) and renal replacement therapy (odds ratio 12.4; p < 0.01) as independent risk factors for increased mortality. CONCLUSIONS: Admission to an intensive care unit was associated with a mortality rate of 21%. Factors associated with poor outcomes included renal replacement therapy, higher admission SAPII scores, and higher admission Charlson comorbidity index. These factors could be used for individual risk assessment on admission to the ICU.

Sonication of retrieved implants improves sensitivity in the diagnosis of periprosthetic joint infection.

BACKGROUND: Sonication is a valuable tool in the diagnosis of periprosthetic joint infections (PJI). However, conditions and definition criteria for PJI vary among studies. The aim of this study was to determine the diagnostic performance (i.e., specificity, sensitivity) of sonicate fluid culture (SFC) against periprosthetic tissue culture (PTC), when using European Bone and Joint Infection Society (EBJIS) criteria. METHODS: From March 2017 to April 2018, 257 implants were submitted for sonication. PJI was defined according to the EBJIS criteria as well as according to the International Consensus Meeting criteria of 2018 (ICM 2018). Only cases with at least one corresponding tissue sample were included. Samples were cultured using traditional microbiological plating techniques. Sensitivity and specificity were determined using two-by-two contingency tables. McNemar's test was used to compare proportions among paired samples. Subgroup analysis was performed dividing the cohort according to the site of PJI, previous antibiotic treatment, and time of manifestation. Prevalence of pathogens was determined for all patients as well as for specific subgroups. RESULTS: Among the 257 cases, 145 and 112 were defined as PJI and aseptic failure, respectively. When using the EBJIS criteria, the sensitivity of SFC and PTC was 69.0 and 62.8%, respectively (p = .04). Meanwhile, the specificity was 90.2 and 92.9%, respectively (p = .65). When adopting ICM 2018 criteria, the sensitivity of SFC and PTC was 87.5 and 84.4% (p = .63) respectively, while the specificity was 85.1 and 92.5% (p = .05), respectively. The most commonly identified pathogens were coagulase-negative staphylococci (26% overall), while 31% of PJI were culture-negative and 9% polymicrobial. CONCLUSIONS: SFC exhibited significantly greater sensitivity versus PTC when using the EBJIS criteria. Nevertheless, the diagnosis of PJI remains a difficult challenge and different diagnostic tools are necessary to optimize the outcome.

Incidence and risk factors for heterotopic ossification following periprosthetic joint infection of the hip.

INTRODUCTION: Heterotopic ossifications (HOs) commonly occur following total hip arthroplasty. Data regarding the appearance of HO after periprosthetic joint infection (PJI) of the hip are rare. Therefore, the aim of this study was to analyze the incidence and potential risk factors for the development of HO in patients with PJI of the hip. MATERIALS AND METHODS: We performed a single-center, retrospective study including patients treated with a two- or multistage operation and patients undergoing salvage procedure in cases of PJI of the hip with a minimum follow-up of 6 months. A total of 150 patients were included in the analysis. The Brooker-scale was used to classify HO. Patients were divided in three groups: (1) No HO, (2) HO Brooker type 1-4, and (3) high-grade HO (HO Brooker type 3 and 4). In each group, we checked possible risk factors for the development of HO for statistical significance. RESULTS: Patients included in our study had a mean age of 70.4 ± 12.1 years. Of all patients, 75 were women (50%). HOs could be found in 70 patients (46.7%). Twenty-seven patients showed HO Brooker type 1, 23 type 2, 15 type 3 and 5 type 4. Male gender [odds ratio (OR) 2.14; p = 0.022], smoking (OR 5.75; p = 0.025) were significant risk factors for HO. A chronic infection (OR 3.54; p = 0.029) and a higher number of procedures (p = 0.009) were significant risk factors for the development of high-grade HO. CONCLUSIONS: HOs often occur following surgical care of PJI. Male gender, smoking, a chronic infection and high number of operations are risk factors for developing HO after PJI.

[Correction of posttraumatic deformities of the distal tibia with focal dome osteotomy]. / Korrektur posttraumatischer Fehlstellungen der distalen Tibia mithilfe der fokalen Domosteotomie.

BACKGROUND: Supramalleolar deformities require surgical correction to avoid posttraumatic osteoarthrosis of the knee or ankle joint and to prevent definitive treatment options, such as total ankle arthroplasty or arthrodesis of the ankle joint. Various methods for the operative correction of supramalleolar deformities have been described in the literature. OBJECTIVE: What results can be achieved with focal dome osteotomy to correct posttraumatic supramalleolar deformities? MATERIAL AND METHODS: A total of 10 patients (mean age 37 years) with a supramalleolar posttraumatic deformity were treated by focal dome osteotomy. The mean follow-up was 27 months (min. 6, max. 105 months), 5 patients were female and 5 male. The supramalleolar varus/valgus deformity was on average 20° (at least 12°, maximum 33°). Preoperative and postoperative mechanical axis and joint angles were determined on digital radiographs. The American Orthopedic Foot and Ankle Society (AOFAS) score was used to assess the clinical outcome. RESULTS: In seven patients the anatomical leg axis could be restored. In three patients a residual deformity of 2.8° was observed. Bone grafting was not necessary in any of the cases. Of the patients eight had free ankle mobility and two showed an average movement limit of 30° compared to the contralateral side. Posttraumatic ankle arthrosis was not observed in the short-term and medium-term results. The mean AOFAS score of 80 points (minimum 70, maximum 98) documented a functionally good result. CONCLUSION: Supramalleolar dome type osteotomy is a technically difficult method for acute correction of supramalleolar deformities. The functional results and complication rates are comparable to those in the literature for alternative osteotomy techniques.

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. / Verbessert die Implementierung des PRO-IMPLANT Foundation Behandlungsalgorithmus die Therapie chronischer periprothetischer Knieprotheseninfektionen? Ergebnisse einer prospektiven Studie.

BACKGROUND: 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. OBJECTIVES: 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. MATERIAL AND METHODS: Between 02/2013 and 09/2016, 122 patients were included in a single-centre cohort analysis. 55 patients 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). CONCLUSION: 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.

Is the bioactivity of induced membranes time dependent?

PURPOSE: The induced membrane technique (IMT) is a two-stage surgical procedure for reconstruction of bone defects. Bone grafting (second stage of IMT) is recommend after 4-8 weeks assuming the highest bioactivity of IMs. However, larger studies concerning the biology and maturation of IMs and a potential time dependency of the bioactivity are missing. Therefore, aim of this study was the time-dependent structural and cellular characterization of cement spacer IMs concomitantly to an analysis of membrane bioactivity. METHODS: IMs from 60 patients (35-82 years) were obtained at different maturation stages (1-16 weeks). IMs were studied by histology and co-culture with mesenchymal stem cells (MSC). IM lysates were analyzed by ELISA and protein microarray. RESULTS: Increasing vascularization and fibrosis were found in membranes older than 4 and 7 weeks, respectively. MSC grew out from all membranes and all membranes enhanced proliferation of cultured MSC. Osteocalcin and osteopontin (in membrane lysates or induced in MSC by membrane tissue) were found over all time points without significant differences. In contrast to alkaline phosphatase activity, increasing levels of osteoprotegerin were found in membranes. CONCLUSION: The histological structure of IMs changes during growth and maturation, however, biologically active MSC and factors related to osteogenesis are found over all time points with minor changes. Thus, membranes older than 8 weeks exert regenerative capacities comparable to the younger ones. The postulated narrow time frame of 4-8 weeks until bone grafting can be questioned and surgeons may choose timing for the second operation more independently and based on other clinical factors.

Erratum to 'Conversion From Knee Arthrodesis Back to Arthroplasty: A Particular Challenge in Combination With Fungal Periprosthetic Joint Infection' [Arthroplasty Today 6 (2020) 1038-1044].

[This corrects the article DOI: 10.1016/j.artd.2020.10.007.].

Sonication in the diagnosis of fracture-related infections (FRI)-a retrospective study on 230 retrieved implants.

BACKGROUND: In fracture-related infections (FRI), both the diagnosis of the infection and the identification of the causative pathogen are crucial to optimize treatment outcomes. Sonication has been successfully used for periprosthetic joint infections (PJI); however, its role in FRI remains unknown. Our aim was to determine the diagnostic accuracy (sensitivity, specificity) of sonicate fluid culture (SFC). The primary objective was to compare SFC with peri-implant tissue culture (PTC) overall and among subgroups using the consensus definition by Metsemakers et al. The secondary objective was to determine the yield of SFC in possible fracture-related infections (PFRI). METHODS: From March 2017 to May 2019, 230 cases of retrieved implants were retrospectively reviewed. To perform sonication, explants were placed in sterile polypropylene jars intraoperatively. After treatment in an ultrasonic bath (Bandelin, Berlin, Germany), sonicate fluid was incubated into blood culture bottles, and conventional culturing was eventually performed. Sensitivity and specificity were determined using two-by-two contingency tables. McNemar's test was used to compare proportions among paired samples while Fisher's exact test was used for comparison between categorical variables. RESULTS: Of the 230 cases, 107 were identified as FRI, whereas 123 were aseptic revision cases (ARC). Of the latter, 105 were labeled as PFRI. Sensitivity of SFC was higher in comparison with PTC, although this did not reach statistical significance (90.7% vs. 84.1%; p = .065). The specificity of SFC was significantly lower than that of PTC (73.2% vs. 88.6%; p = .003). In PFRI, SFC yielded significantly more positive results than PTC (33/105 vs. 14/105; p = .003). Overall, 142 pathogens were identified by SFC, whereas 131 pathogens were found by PTC. CONCLUSIONS: We found that sonication of fracture fixation devices may be a useful adjunct in FRI, especially in "low-grade" infections lacking confirmatory clinical criteria. Standardized diagnostic protocols are warranted in order to further optimize the diagnostic accuracy.

Three-stage revision arthroplasty for the treatment of fungal periprosthetic joint infection: outcome analysis of a novel treatment algorithm : a prospective study.

AIMS: Fungal periprosthetic joint infections (fPJIs) are rare complications, constituting only 1% of all PJIs. Neither a uniform definition for fPJI has been established, nor a standardized treatment regimen. Compared to bacterial PJI, there is little evidence for fPJI in the literature with divergent results. Hence, we implemented a novel treatment algorithm based on three-stage revision arthroplasty, with local and systemic antifungal therapy to optimize treatment for fPJI. METHODS: From 2015 to 2018, a total of 18 patients with fPJI were included in a prospective, single-centre study (DKRS-ID 00020409). The diagnosis of PJI is based on the European Bone and Joint Infection Society definition of periprosthetic joint infections. The baseline parameters (age, sex, and BMI) and additional data (previous surgeries, pathogen spectrum, and Charlson Comorbidity Index) were recorded. A therapy protocol with three-stage revision, including a scheduled spacer exchange, was implemented. Systemic antifungal medication was administered throughout the entire treatment period and continued for six months after reimplantation. A minimum follow-up of 24 months was defined. RESULTS: Eradication of infection was achieved in 16 out of 18 patients (88.8%), with a mean follow-up of 35 months (25 to 54). Mixed bacterial and fungal infections were present in seven cases (39%). The interval period, defined as the period of time from explantation to reimplantation, was 119 days (55 to 202). In five patients, a salvage procedure was performed (three cementless modular knee arthrodesis, and two Girdlestone procedures). CONCLUSION: Therapy for fPJI is complex, with low cure rates according to the literature. No uniform treatment recommendations presently exist for fPJI. Three-stage revision arthroplasty with prolonged systemic antifungal therapy showed promising results. Cite this article: Bone Jt Open 2021;2(8):671-678.

Facing multidrug-resistant pathogens in periprosthetic joint infections with self-administered outpatient parenteral antimicrobial therapy-A prospective cohort study.

A key factor in the successful management of periprosthetic joint infection (PJI) besides the surgical regime is a consistent antimicrobial therapy. Recently, oral versus intravenous (IV) antibiotics for bone and joint infection trial demonstrated the noninferiority of oral antimicrobial therapy compared to IV, implying that an early transition to oral administration is reasonable. It is likely that the international consensus meeting of musculoskeletal Infections and the European Bone and Joint Infection Society will consider these findings. However, rising levels of antimicrobial resistance are challenging and recommendations for dealing with multidrug-resistant (MDR) pathogens resistant to oral antibiotics are lacking. This study focuses on establishing guidance towards their management in PJI. From December 2015 to June 2019, patients with MDR pathogens were included in a single-center prospective cohort study and treated with self-administered outpatient parenteral antimicrobial therapy (S-OPAT) based on a two-stage revision strategy. Demographics, pathogens, antimicrobial agents, and outcomes were recorded. A total of 1738 outpatient days in 26 patients were analyzed. The incidence of pathogens resistant to oral antibiotics in PJI was 4%, most frequently encountered were staphylococcus epidermidis. The Kaplan-Meier-estimated infection-free survival after 3 years was 90% (95% confidence interval, 84.6%-95.5%). We recorded adverse events in 6 of 54 (11%) S-OPAT episodes (3.45/1000 S-OPAT days). (i) S-OPAT in two-stage revision arthroplasty to counter increasing numbers of MDR pathogens resistant to oral agents can achieve a high infection eradication rate and (ii) should therefore be taken into account at the next society's consensus treatment updates.

Tantalum Augments Combined with Antiprotrusio Cages for Massive Acetabular Defects in Revision Arthroplasty.

BACKGROUND: Tantalum components have gained popularity for the management of Paprosky type IIIA and IIIB defects during revision total hip arthroplasty. Although the use of antiprotrusio cages solely shows suboptimal results, there are certain defects that still require their use. We hypothesized that combining tantalum augments and an antiprotrusio cage would (1) improve radiographic stability, (2) enhance survivorship, (3) decrease complications, and (4) improve clinical outcomes. METHODS: We retrospectively reviewed 20 patients with Paprosky type IIIA or IIIB defects who underwent revision of the acetabular component with a highly porous tantalum augment and an antiprotrusio cage combination. Preoperative and postoperative radiographs, survivorship free from aseptic component revision, and the Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, and Short Form-36 scores were analyzed. The mean follow-up was 2.8 years. RESULTS: At the most recent follow-up, no antiprotrusio cages had migrated and all tantalum augments had radiographic evidence of osseointegration. In addition, only 2 components were revised for aseptic etiologies and only 1 was loose. Both were revised secondary to failures of the inferior flange of the antiprotrusio cage. All clinical outcome scores significantly improved postoperatively. Finally, the risk of major postoperative complications was noted to be 10%. CONCLUSIONS: In summary, a tantalum augment combined with an antiprotrusio cage in Paprosky IIIA and IIIB defects with divergent anatomy not amenable to a hemispherical socket provides a reliable technique to restore the anatomic hip center and prevent superior migration and provides a bony ingrowth surface. Longer term follow-up is required before the technique is widely adapted. LEVEL OF EVIDENCE: Level IV, therapeutic studies.

Conversion From Knee Arthrodesis Back to Arthroplasty: A Particular Challenge in Combination With Fungal Periprosthetic Joint Infection.

A 58-year-old female treated at an outside facility with knee arthrodesis due to persistent periprosthetic joint infection fulfilled all prerequisites for a conversion back to arthroplasty, as part of a 2-stage revision. Owing to the detection of Candida parapsilosis, the treatment concept was converted to a three-stage procedure. A scheduled spacer exchange with additional amphotericin B-loaded polymethylmethacrylate was conducted as an intermediate revision before reimplantation. Conversion in the setting of fungal periprosthetic joint infection presents a challenge, and successful treatment hinges on the use of proper antifungal and antimicrobial protocols, advanced surgical techniques, and a multidisciplinary team approach. At the 3-year follow-up, successful infection eradication as measured by the Delphi-based consensus definition was achieved with a range of motion of 0°-100°.

Microbial findings and the role of difficult-to-treat pathogens in patients with periprosthetic infection admitted to the intensive care unit.

Little is known about patients with Periprosthetic Joint Infection (PJI) admitted to the Intensive Care Unit (ICU). The purpose of this study was threefold: i) To report the microbiological findings of ICUpatients with PJI. ii) To compare the clinical data between Difficult-To-Treat (DTT) and non-DTT PJI. iii) To identify risk factors for mortality. This is a retrospective study from a tertiary healthcare center in Germany from 2012-2016. A total of 124 patients with 169 pathogens were included. The most common bacteria were Staphyloccous aureus (26.6%), Staphyloccus epidermidis (12.4%), Enterococci ssp. and Escherichia coli (respectively 9.4%). DTT PJI was diagnosed in 28 patients (22.6%). The main pathogens of DTT PJI were Staphylococus epidermidis (14.5%), Escherichia coli (12.7%), Staphylococcus aureus and Candida spp. (respectively 9.1%). Polymicrobial PJI, number of pathogens, ICU stay and mortality were significantly differrent between DTT PJI and non-DTT PJI (p≤0.05). Multivariate logistic regression identified prolonged ICU stay and DTT PJI as risk factors for mortality. In conclusion, we suggest, that the term of DTT pathogens is useful for the intensivist to assess the clinical outcome in ICU-patients with PJI.

Outpatient Parenteral Antibiotic Therapy (OPAT) with Peripherally Inserted Central Catheter in Patients with Periprosthetic Joint Infection. / Die ambulante i. v. Antibiotikatherapie mittels PICC Line in der Behandlung von chronischen periprothetischen Infektionen.

BACKGROUND: A key factor in the successful treatment of periprosthetic joint infection is the consistent antimicrobial therapy. Depending on the pathogen antimicrobial susceptibility, intravenous (i. v.) antibiotics may not be switched to oral medication at patient discharge, without risking a treatment failure. The implementation of an outpatient i. v. therapy using peripherally inserted central catheters (PICCs) allows for early discharge with continuation of adequate antimicrobial therapy. METHODS: We prospectively evaluated the systematic use of PICC in 11 patients with periprosthetic joint infection. Inclusion criterion was the detection of a pathogen that cannot be optimally treated with oral antibiotics according to the current treatment concept (Trampuz et al.). RESULTS: A total of 12 PICCs in 11 patients were analysed. An error or mechanical nerve irritation was not observed. The occurrence of a catheter-related bloodstream infection (CRBSI) was not recorded. None of our patients had PICC-associated infections, thrombophlebitis or thrombosis. One patient stopped therapy due to a lack of compliance. Ten patients successfully completed their treatment. At a mean follow-up of 29 months, successful infection eradication as measured by the Delphi criteria was achieved in 100%. CONCLUSION: Although the number of patients included in the study was small, our short-term results suggest a good applicability of PICCs in the outpatient i. v. antimicrobial therapy for treatment of periprosthetic joint infection. Catheter-associated complications could not be observed in our collective. The successful infection control in all cases despite proven difficult-to-treat infection is promising.

Risk analysis and clinical outcomes of intraoperative periprosthetic fractures: a retrospective study of 481 bipolar hemiarthroplasties.

BACKGROUND: Intraoperative periprosthetic fractures (IPF) are a well-described complication following hip hemiarthroplasty. Our aims were to identify risk factors that characterize IPF and to investigate postoperative mobility. METHODS: We retrospectively reviewed 481 bipolar hemiarthroplasties for displaced femoral neck fractures; of which, 421 (87.5%) were performed without cement, from January 2013 to March 2018. Data on the patients' demographics, comorbidities, femoral canal geometry (Dorr canal type, Canal Flare Index), surgeon's experience (junior vs. senior surgeon), and timing of surgery (daytime vs. on-call duty) were obtained. In patients with intraoperative fractures, further information was obtained. Patient mobility was assessed using matched-pair analysis. Mobility was classified according to the NHFD mobility score. The chi-square test, Fisher's exact test, and Fisher-Freeman-Halton exact test were used for comparison between categorical variables, while the Mann-Whitney U test was used for continuous variables. The data analysis was performed using SPSS. RESULTS: Of 481 procedures, 34 (7.1%) IPFs were encountered. The Dorr canal type C was identified as a significant risk factor (p = .004). Other risk factors included female sex (OR 2.30, 95% CI .872-6.079), stovepipe femur (OR 1.749, 95% CI .823-3.713), junior surgeon (OR 1.204, 95% CI .596-2.432), and on-call-duty surgery (OR 1.471, 95% CI .711-3.046), although none showed a significant difference. Of 34 IPFs, 25 (73.5%) were classified as Vancouver type A. The treatment of choice was cerclage wiring. Within the 12 matched pairs identified, the postoperative mobility was slightly worse for the IPF group (delta = .41). CONCLUSIONS: IPF is a serious complication with bipolar hemiarthroplasty. The identification of risk factors preoperatively, in particular femur shape, is crucial and should be incorporated into the decision-making process.