In Vitro Biocompatibility of the Novel Ceramic Composite Baghdadite for Defect Augmentation in Revision Total Hip Arthroplasty.

Biological augmentation of bony defects in weight-bearing areas of both the acetabulum and the femur remains challenging. The calcium-silicate-based ceramic Baghdadite is a very interesting material to be used in the field of revision total hip arthroplasty for the treatment of bony defects in weight-bearing and non-weight-bearing areas alike. The aim of this study was to investigate the biocompatibility of Baghdadite utilizing an osteoblast-like, human osteosarcoma cell line (MG-63) and the human monocytic leukemia-derived cell line (THP-1). THP-1-derived macrophages and MG-63 were indirectly exposed to Baghdadite for 7 days using a transwell system. Viability was assessed with MTT assay and pH analysis. To investigate proliferation rate, both cell lines were labelled using CFSE and flow cytometrically analyzed. ELISA was used to measure the secretion of IL-1ß, IL-6 and TNFα. The investigation of viability, while showing a slight difference in optical density for the MTT assays in MG-63 cells, did not present a meaningful difference between groups for both cell lines. The comparison of pH and the proportion of living cells between groups did not present with a significant difference for both THP-1 and MG-63. Baghdadite did not have a relevant impact on the proliferation rate of the investigated cell lines. Mean fluorescence intensity was calculated between groups with no significant difference. Baghdadite exerted a proinflammatory effect, which could be seen in an upregulated production of TNFα in macrophages. Production of IL-1ß and IL-6 was not statistically significant, but the IL-6 ELISA showed a trend to an upregulated production as well. A similar effect on MG-63 was not observed. No relevant cytotoxicity of Baghdadite ceramics was encountered. Baghdadite ceramics exhibit a proinflammatory potential by significantly increasing the secretion of TNFα in THP-1-derived macrophages. Whether this proinflammatory potential results in a clinically relevant effect on osteointegration is unclear and requires further investigation. Baghdadite ceramics provide an interesting alternative to conventional bone substitutes and should be further investigated in a biomechanical and in vivo setting.

[Customized partial pelvis replacement: three-dimensional planning and management concepts]. / Individuelle Beckenteilersatz-Implantate: 3-D-Planung und Versorgungskonzepte.

The planning and implantation of a customized partial pelvis replacement places high demands on both the surgeon and the entire team (engineer, assistants, surgical team). Thanks to careful preoperative planning and meticulous perioperative execution, customized partial pelvic replacement represents a complex but reliable procedure for defect reconstruction even with highly complex acetabular bone defects or after multiple previous surgeries.

Effects of Different Hemoglobin Levels on Near-Infrared Spectroscopy-Derived Cerebral Oxygen Saturation in Elderly Patients Undergoing Noncardiac Surgery.

Background: Near-infrared spectroscopy (NIRS) is a commonly used technique to evaluate tissue oxygenation and prevent harmful cerebral desaturation in the perioperative setting. The aims of the present study were to assess whether surgery-related anemia can be detected via NIRS of cerebral oxygen saturation and to investigate the effects of different perioperative transfusion strategies on cerebral oxygenation, potentially affecting transfusion decision-making. Study Design and Methods: Data from the ongoing multicenter LIBERAL-Trial (liberal transfusion strategy to prevent mortality and anemia-associated ischemic events in elderly noncardiac surgical patients, LIBERAL) were used. In this single-center sub-study, regional cerebral oxygenation saturation (rSO2) was evaluated by NIRS at baseline, pre-, and post-RBC transfusion. The obtained values were correlated with blood gas analysis-measured Hb concentrations. Results: rSO2 correlated with Hb decline during surgery (r = 0.35, p < 0.0001). Different RBC transfusion strategies impacted rSO2 such that higher Hb values resulted in higher rSO2. Cerebral desaturation occurred at lower Hb values more often. Discussion: Cerebral oxygenation monitoring using NIRS provides noninvasive rapid and continuous information regarding perioperative alterations in Hb concentration without the utilization of patients' blood for blood sampling. Further investigations are required to demonstrate if cerebral rSO2 may be included in future individualized transfusion decision strategies.

COVID-19 measures as an opportunity to reduce the environmental footprint in orthopaedic and trauma surgery.

Background: Climate change and its consequences on our everyday life have also tremendous impacts on public health and the health of each individual. The healthcare sector currently accounts for 4.4% of global greenhouse gas emissions. The share of the emissions in the health care system caused by the transportation sector is 7%. The study analyses the effect of video consultation on the CO2 emissions during the Covid-19 pandemic in an outpatient clinic of the department of orthopaedics and traumatology surgery at a German university hospital. Methods: The study participants were patients who obtained a video consultation in the period from June to December 2020 and voluntarily completed a questionnaire after the consultation. The type of transport, travel time and waiting time as well as patient satisfaction were recorded by questionnaire. Results: The study comprised 51 consultations. About 70% of respondents would have travelled to the clinic by car. The reduction in greenhouse gas emissions of video consultations compared to a face-to-face presentation was 97% in our model investigation. Conclusion: The video consultation can be a very important part of the reduction of greenhouse gas emissions in the health care system. It also saves time for the doctor and patient and can form an essential part of individual patient care.

Temporary arthrodesis through static spacer implantation in two-stage treatment of periprosthetic joint infections of the knee.

OBJECTIVE: Treatment of chronic periprosthetic joint infection of the knee requires the removal of the implant and thorough debridement, with reimplantation in a second stage surgery. Intramedullary spacers can be helpful during the interval between explantation and reimplantation and provide a temporary arthrodesis which fixes the knee in extension preserving leg length and administers local antibiotic therapy. INDICATIONS: Periprosthetic joint infection of the knee with large bony defects and severe infection of the native joint with advanced destruction/infiltration of the cartilage and bone and/or ligament insufficiency. CONTRAINDICATIONS: Suspected antibiotic resistance of the microbiological pathogen to local antibiotic drugs, incompliant patient, and known allergy to bone cement or antibiotic. SURGICAL TECHNIQUE: After implant removal, suitable metal rods are coated with antibiotic-loaded bone cement and inserted into the cleaned intramedullary canals of femur and tibia. Rods are joined at the joint line with a connector and joint space is filled with more bone cement to achieve temporary and very stable arthrodesis. POSTOPERATIVE MANAGEMENT: Partial weight-bearing and no flexion/extension while spacer is in place; second stage reimplantation as soon as infection is controlled. RESULTS: Complications related to the spacer were rare (5.3%). Reimplantation of an implant was possible in 95 of 113 patients (84%), of those, 23 (20%) received an arthrodesis. Of the 95 patients that were reimplanted, 14 showed signs of recurrent infection. Mean time to last follow-up was 15.6 months post reimplantation. Mean knee pain was 2.9/10; overall function was good; 6 patients had an extension lag; mean total range of motion was 88°.

Commercially manufactured spacers for the treatment of periprosthetic joint infection of the hip.

BACKGROUND: Periprosthetic joint infection remains a common and serious complication after hip arthroplasty. To improve function and patient comfort after joint removal in two-stage revision, commercially manufactured spacers for the hip joint allow retention of the anatomical joint geometry thereby limiting soft tissue contraction and allow mobilization. INDICATIONS: Periprosthetic joint infection of the hip, septic arthritis with severe destruction of the hip cartilage and/or bone requiring arthroplasty. CONTRAINDICATIONS: Allergies to polymethylmethacrylate (PMMA) or antibiotics, severe hip dysplasia with insufficient cranial support, incompliant patient, large osseous defect of the acetabulum, insufficient metaphyseal/diaphyseal support of the femoral bone, resistance of the microbiological pathogen to spacer-inert antibiotic medication, inability to perform primary wound closure requiring temporary open-wound therapy. SURGICAL TECHNIQUE: Preoperative templating on radiograph; removal of joint prosthesis and thorough debridement with removal of all foreign material; trial spacer selection and insertion and trial reduction of the joint, fixing the spacer with PMMA to the proximal femur, final reduction, radiograph and stability test. RESULTS: Data were analyzed from patients treated between 2016 and 2021. In all, 20 patients were treated with preformed spacers and 16 with custom-made spacers. Pathogens were detected in 23 of the 36 cases (64%). Polymicrobial infections were present in 8 of 36 cases (22%). In patients who received preformed spacers, there were 6 cases of spacer-related complications (30%). Of the 36 patients (83%), 30 were reimplanted with a new implant; 3 patients died due to septic or other complications before reimplantation (8%). Average follow-up was 20.2 months after reimplantation. There were no major differences between the two groups of spacers. Patient comfort was not measured.

Surgical technique and preliminary results of a moulded, mobile spacer for the treatment of periprosthetic joint infection of the knee.

OBJECTIVE: Mobile knee spacers can be utilized in the first stage of a two-stage exchange in periprosthetic joint infection or septic arthritis of the knee to prevent soft tissue contraction, enable local antibiotic elution, and improve patient mobility. Commercially made moulds enable the surgeon to prepare a reproducible spacer design and match the preparation of the arthroplasty, which will be carried out in a second step. INDICATIONS: Periprosthetic joint infection of the knee and severe cases of septic arthritis of the knee with advanced destruction/infiltration of the cartilage. CONTRAINDICATIONS: Antibiotic resistance of the microbiological pathogen to available antibiotic agents, incompliant patient, large osseous defect preventing proper fixation, known allergy to polymethylmethacrylate (PMMA) or antibiotic, severe soft tissue damage with high ligament instability, especially deterioration of extensor mechanism and insufficient patella/quadricep tendon. SURGICAL TECHNIQUE: After thorough debridement and removal of all foreign material, cutting blocks are used to shape femur and tibia to the implant design required. Using a silicone mould, PMMA with suitable antibiotics is moulded into the shape of the future implant. After polymerization, the implants are fixed onto the bone with additional PMMA without pressurize for the sake of easy removal. POSTOPERATIVE MANAGEMENT: Partial weight bearing with no restriction of flexion/extension while spacer is in place; second stage reimplantation as soon as infection is controlled. RESULTS: In all, 22 cases were treated, mostly with a PMMA spacer containing gentamicin and vancomycin. Pathogens were detected in 13 of 22 cases (59%). We observed two complications (9%). Twenty of 22 patients (86%) were reimplanted with a new arthroplasty; 16 of the 20 patients remained revision-free and infection-free at the last follow-up (average time to follow-up 13 months, range 1-46 months). Average range of motion in flexion and extension at follow-up was 98°.

Periprosthetic joint infection caused by kytococcus schroeteri: The first reported case and a review of the literature.

Oftentimes, Gram-positive cocci are the cause for periprosthetic joint infections (PJI). Most of these infections include bacteria such as Staphylococcus aureus, Staphylococcus epidermidis or other coagulase-negative staphylococci. We here present the first case of a PJI caused by Kytococcus schroeteri. While being a Gram-positive coccus, it is very rarely the cause for infections in the human body. K. schroeteri is part of the micrococcus branch and often encountered as a symbiotic bacterium living on the skin. Regarding its pathogenic potential, not a lot is known since less than a few dozen human infections have been reported worldwide. Furthermore, many of the cases reported are either associated with implanted material, especially heart valves, or associated with patients whose immune response is deficient. Only 3 reports of osteoarticular infections are described so far.

Ceramic Wear Particles: Can They Be Retrieved In Vivo and Duplicated In Vitro?

BACKGROUND: Little is known about retrieved zirconia platelet toughened alumina (ZPTA) wear particles from ceramic-on-ceramic (COC) total hip arthroplasty. Our objectives were to evaluate clinically retrieved wear particles from explanted periprosthetic hip tissues and to analyze the characteristics of in vitro-generated ZPTA wear particles. METHODS: Periprosthetic tissue and explants were received for 3 patients who underwent a total hip replacement of ZPTA COC head and liner. Wear particles were isolated and characterized via scanning electron microscopy and energy dispersive spectroscopy. The ZPTA and control (highly cross-linked polyethylene and cobalt chromium alloy) were then generated in vitro using a hip simulator and pin-on-disc testing, respectively. Particles were assessed in accordance with American Society for Testing and Materials F1877. RESULTS: Minimal ceramic particles were identified in the retrieved tissue, consistent with the retrieved components demonstrating minimal abrasive wear with material transfer. Average particle diameter from in vitro studies was 292 nm for ZPTA, 190 nm for highly cross-linked polyethylene, and 201 nm for cobalt chromium alloy. CONCLUSION: The minimal number of in vivo ZPTA wear particles observed is consistent with the successful tribological history of COC total hip arthroplasties. Due to the relatively few ceramic particles located in the retrieved tissue, in part due to implantation times of 3 to 6 years, a statistical comparison was unable to be made between the in vivo particles and the in vitro-generated ZPTA particles. However, the study provided further insight into the size and morphological characteristics of ZPTA particles generated from clinically relevant in vitro test setups.

Open Access Redefined: Survey Data and Literature Study on the Impact of Sci-Hub in Orthopaedic Research.

BACKGROUND: Since Alexandra Elbanyan founded Sci-Hub in 2011, the website has been used by a growing number of researchers worldwide. Sci-Hub is a so-called shadow library or guerrilla open access format bypassing publishers' paywalls, giving everyone free access to scientific papers. Until today, there have been no publications about usage by orthopaedic and trauma surgeons of Sci-Hub or other "pirate sites" and how it may influence their work. MATERIALS AND METHODS: Orthopaedic and trauma surgeons of four university hospitals in Germany and Europe were consulted using a standardised questionnaire containing multiple items about the use and evaluation of Sci-Hub. In addition, the Medline and Cochrane databases were screened for all studies related to Sci-Hub. Two reviewers independently reviewed all articles and the references of these articles. RESULTS: Of all orthopaedic surgeons consulted, 69% knew of Sci-Hub and 66.7% used it on a regular basis. Of the younger participants (< 45 years old), 77% knew the webpage, while only 25% of older participants (> 45 years old) knew the webpage. Ninety percent found the quality of their citation and research had been enhanced since using Sci-Hub. On a scale of 1 to 10, user-friendliness was rated with a mean rating of 7.58 (95% CI: 7.262-7.891). Ethical or legal concerns among users seem mixed. On a scale of 1 (no concerns) to 5 (many concerns), the mean score was 2.39 (95% CI: 2.154-2.615). Of doctors using Sci-Hub, 89% would recommend it to other colleagues. CONCLUSION: The quality and number of articles in Sci-Hub is outstanding, and the rate of young researchers using the website is high. The most important shift in literature research for decades is a phenomenon mostly used by young researchers and is not the subject of current research itself. Sci-Hub may have already changed how orthopaedic research works.

Preoperative embolization of renal cell carcinoma metastases to the bone prior to stabilization procedures does not result in reduction in intraoperative blood loss.

PURPOSE: The effect of preoperative embolization of bone metastases prior to stabilization procedures in reducing intraoperative blood loss remains controversial. This study aimed to analyze the effect of preoperative embolization on orthopedic stabilization procedures of the extremities and spine in cases with bone metastases from renal cell carcinomas. In particular, do these patients suffer less blood loss during the operation and do they need lesser fluid replacements or packed red cell bags intra- and perioperatively? Does preoperative embolization reduce the duration of surgery? METHODS: We retrospectively reviewed stabilization procedures of the spine and extremities at our institution between 2011 and 2021 for group differences (embolization vs. no embolization) in terms of blood loss, fluid substitution, need for packed red cell transfusions, tumor size, and duration of surgery. RESULTS: We reviewed 79 stabilization procedures of the spine (n = 36) and extremities (n = 43), of which 30 included preoperative embolization procedures. Surprisingly, the embolization group showed a statistically significant increase in blood loss, the need for fluid substitution, and red cell transfusions. Subgroup analysis revealed a significant negative effect of preoperative embolization on stabilization procedures of the extremities. CONCLUSION: Based on our data, preoperative embolization of renal cell carcinoma metastases of the extremities had a negative effect on intraoperative blood loss and the need for fluid substitution and should therefore be avoided. Our data did not show an effect on stabilization procedures of the spine.

Femoral defects in revision hip arthroplasty: a therapy-oriented classification.

INTRODUCTION: The complex field of femoral defects in revision hip arthroplasty displays a lack of standardized, intuitive pre- and intraoperative assessment. To address this issue, the femoral defect classification (FDC) is introduced to offer a reliable, reproducible and an intuitive classification system with a clear therapeutic guideline. MATERIALS AND METHODS: The FDC is based on the integrity of the main femoral segments which determine function and structural support. It focuses on the femoral neck, the metaphysis consisting of the greater and lesser trochanter, and the femoral diaphysis. The four main categories determine the location of the defect while subcategories a, b and c are being used to classify the extent of damage in each location. In total, 218 preoperative radiographs were retrospectively graded according to FDC and compared to intraoperatively encountered bone defects. To account for inter-rater and intra-rater agreement, 5 different observers evaluated 80 randomized cases at different points in time. RESULTS: A Cohens kappa of 0.832 ± 0.028 could be evaluated, accounting for excellent agreement between preoperative radiographs and intraoperative findings. To account for inter-rater reliability, 80 patients have been evaluated by 5 different observers. Testing for inter-rater reliability, a Fleiss Kappa of 0.688 could be evaluated falling into the good agreement range. When testing for intra-rater reliability, Cohens Kappa of each of the 5 raters has been analyzed and the mean was evaluated at 0.856 accounting for excellent agreement. CONCLUSION: The FDC is a reliable and reproducible classification system. It combines intuitive use and structured design and allows for consistent preoperative planning and intraoperative guidance. A therapeutic algorithm has been created according to current literature and expert opinion. Due to the combination of the FDC with the recently introduced Acetabular Defect Classification (ADC) a structured approach to the entire field of hip revision arthroplasty is now available.

Microbiological Trends and Antibiotic Susceptibility Patterns in Patients with Periprosthetic Joint Infection of the Hip or Knee over 6 Years.

We sought to analyze trends of the causative pathogens and their antibiotic susceptibility patterns in patients with periprosthetic joint infections (PJI) of the hip and knee to get better insights and improve treatment. Retrospective evaluation of all consecutive patients with microbiological detection of a causative pathogen at a tertiary endoprothetic referral center between January 2016 and December 2021 in Germany was performed. Overall, 612 different microorganisms could be detected in 493 patients (hip: n = 293; knee: n = 200). Evaluation did not show a change in the relative abundance of pathogens detected, with coagulase-negative staphylococci (n = 275; 44.9%) found frequently, followed by S. aureus (n = 86; 14.1%), Enterococcus species (n = 57; 9.3%), Streptococcus species (n = 48; 7.8%), and Gram-negative bacteria (n = 80; 13.1%). Evaluation of the antibiotic susceptibilities showed increasing rates of oxacillin-resistant coagulase-negative staphylococci (60.4%; 46.8−76.7%) and piperacillin-tazobactam-resistant Gram-negative bacteria (26.5%; 0−57.1%), although statistically not significant. Resistance of Gram-positive bacteria to vancomycin (<1%) and Gram-negative microorganisms to meropenem (1.25%) remained an exception. In summary, coagulase-negative staphylococci, as the most frequent pathogen, displayed a continuously high rate of oxacillin resistance. For the highest antimicrobial coverage in the case of an empiric therapy/unknown pathogen, vancomycin might be chosen. Level of evidence: IV.

Pain levels and patient comfort after lower limb arthroplasty comparing i.v. patient-controlled analgesia, continuous peripheral nerve block and neuraxial analgesia: a retrospective cohort analysis of clinical routine data.

BACKGROUND: Insufficient pain control after lower limb arthroplasty results in delayed recovery and increased risk for pain chronicization. The ideal kind of analgesia is still discussed controversially. We conducted a retrospective analysis of single-center routine data from a German university hospital, including patients receiving either total hip (THA) or knee arthroplasty (TKA). METHODS: All patients received general anesthesia. Patients undergoing THA received either continuous epidural ropivacaine infusion (0.133%, Epi) or patient-controlled analgesia (PCA) with the Wurzburg Pain Drip (tramadol, metamizole and droperidol, WPD) or with piritramide (Pir). After TKA, patients received either continuous femoral nerve block (ropivacaine 0.2%, PNB) or Pir. RESULTS: The analyzed cohort comprised 769 cases. Use of WPD after THA (n = 333) resulted in significantly reduced Numeric Rating Scale (NRS) values at rest, compared to Epi (n = 48) and Pir (n = 72) (.75 [IQR 1.14] vs. 1.17 [1.5], p = .02 vs. 1.47 [1.33], p < .0001) as well as maximum NRS scores (2.4 [1.7] vs. 3.29 [1.94], p < .001 vs. 3.32 [1.76], p < .0001). Positive feedback during follow-up visits was significantly increased in patients with a WPD PCA (p < .0001), while negative feedback (senso-motoric weakness/technical problems/nausea/dizziness/constipation) was particularly increased in Epi patients and lowest in those with WPD (p < .0001). After TKA, Pir (n = 131) resulted in significantly reduced NRS values at rest, compared to PNB (n = 185) (1.4 [1.4] vs. 1.6 [1.68], p = .02). Positive feedback was increased in patients with a Pir PCA in comparison with PNB (p = .04), while negative feedback was increased in PNB patients (p = .04). Overall, WPD presented with the lowest rate of any complications (8.7%), followed by Pir (20.2%), PNB (27.6%) and Epi (31.3%) (p < .001). CONCLUSIONS: In the assessed population, the use of a WPD PCA after THA offered better pain control and patient comfort in comparison with continuous epidural or piritramide-based analgesia. After TKA, the use of a Pir PCA provided superior analgesia and a lower complication rate compared to continuous PNB.

Microbiological Profiles of Patients with Periprosthetic Joint Infection of the Hip or Knee.

Periprosthetic joint infections (PJI) are one of the most devastating consequences after total joint arthroplasty. We sought to analyze the causative pathogens of patients with PJI to get better insights and improve treatment. We performed a retrospective study of all patients with PJI of the hip and knee with microbiological detection of a causative pathogen at a tertiary endoprothetic referral center between January 2016 and March 2021. A total of 432 cases with PJI (hip: n = 250; knee: n = 182) were included. The most common causative pathogen were coagulase-negative staphylococci (n = 240; 44.2%), of which Staphylococcus epidermidis (n = 144; 26.7%) was the most frequently detected, followed by S. aureus (n = 77; 14.3%) and enterococci (n = 49; 9%). Gram-negative pathogens and fungi could be detected in 21% (n = 136) and 2.4% (n = 13) of all cases. Overall, 60% of all coagulase-negative staphylococci were oxacillin-resistant, while none of these displayed to be vancomycin-resistant. In summary, the majority of pathogens in cases of PJI could be identified as coagulase-negative staphylococci. For empirical therapy vancomycin might provide the highest antimicrobial coverage in case of an unknown pathogen.

Increased rate of enteric bacteria as cause of periprosthetic joint infections in patients with liver cirrhosis.

INTRODUCTION: Periprosthetic joint infections (PJI) are a major complication in joint-arthroplasty. Rifampicin is often used as an additional agent to treat PJI, because it penetrates bacterial biofilms. However, rifaximin, belonging to the same antibiotic class as rifampicin, is frequently used to prevent episodes of hepatic encephalopathy in patients with cirrhosis and may induce resistance to rifampicin. The aim of this study was to examine the microbial pattern of periprosthetic joint infections in cirrhotic patients and to test the hypothesis that intake of rifaximin increases the rate of resistance to rifampicin in periprosthetic joint infections. METHODS: A cohort of cirrhotic patients and PJI (n = 25) was analysed on the characteristics of bacterial isolates from sonication and tissue analysis. In a second step a subgroup analysis on the development of rifampicin resistant bacterial specimens, depending on the intake of rifaximin (8 rifaximin intake patients vs. 13 non rifaximin intake patients) was performed. RESULTS: Intestinal bacteria were found in 50% of the specimens, which was significantly more frequent than in a control cohort. By comparison of the single bacterial isolates, rifampicin resistance was detected in 69.2% (9/13) of the rifaximin-intake samples. In contrast, the non-rifaximin-intake isolates only were resistant to rifampicin in 22.2% (4/18) of the cases (p = 0.01). The odds ratio for developing a rifampicin-resistance through rifaximin intake was calculated as OR = 13.5. CONCLUSION: Periprosthetic joint infections have a high incidence of being caused by enteric bacteria in cirrhotic patients. Due to this change in microbial pattern and the innate resistance to rifampicin of most of gram-negative bacteria, the therapy with rifampicin should be carefully considered. The association between the use of rifaximin and developed resistance to rifampicin has a major impact on the treatment of PJI.

[Use of custom-made acetabular components (CMAC) as part of a two-stage procedure in patients with severe periacetabular bone loss]. / "Custom-made acetabular components" (CMAC) beim zweizeitigen Wechsel und bei höhergradigen periazetabulären Knochendefekten.

OBJECTIVE: Implantation of custom-made acetabular components (CMAC) with load transmission onto the remaining bone stock and reconstruction of the "center of rotation" (COR) in cases of severe periacetabular bone defects. INDICATIONS: Severe periacetabular bone loss (Paprosky type IIIA/B) with or without pelvic discontinuity after septic or aseptic loosening with inadequate load capacity of the dorsal pillar and/or large supraacetabular defects. CONTRAINDICATIONS: Acute or local infections, lack of compliance, taking into account the risks and complications: missing or limited expected postoperative functional gain, multimorbid patients with potential inoperability during the first and/or second intervention. SURGICAL TECHNIQUE: Lateral transgluteal or posterolateral approach while protecting neurovascular and muscular structures. Preparation of the implant site based on preoperative planning with augmentation of bone defects as far as possible. Primarily stable anchoring with 2 angle-stable pole screws in the ilium, an optional pole screw in the pubic bone for determination of COR, and stabilization screws in the iliac wing (optionally angle-stable). Use of dual mobility cup according to the soft tissue tension and intraoperative stability. POSTOPERATIVE MANAGEMENT: For the first 6 weeks postoperative partial weight-bearing (20 kg), followed by a gradual increase of the load (10 kg per week). RESULTS: Between 2008 and 2018, 47 patients with a Paprosky type III defect underwent implantation of a monoflanged CMAC. Main complication was a periprosthetic joint infection with subsequent need for implant removal in 9 of 10 cases. Harris Hip Score improved from 21.1 to 61.5 points. X­ray imaging displayed an angle of inclination of 42.3 ± 5.3°, an anteversion of 16.8 ± 6.2°, a ∆ H of 0.5 ± 0.2 mm and a ∆ V of 17.7 ± 1.1 mm according to Roessler et al.

Risk factors for implant failure of custom-made acetabular implants in patients with Paprosky III acetabular bone loss and combined pelvic discontinuity.

BACKGROUND: Severe acetabular bone loss in revision total hip arthroplasty (RTHA), both with or without pelvic discontinuity, remains a great challenge in orthopaedic surgery. OBJECTIVE: The aim of this study was to evaluate risk factors for failure of custom-made acetabular implants in RTHA. METHODS: Seventy patients with severe acetabular bone loss (Paprosky Type III) and pelvic discontinuity, who required RTHA, were included in our study. All prostheses were constructed based on a thin-layer computed-tomography (CT) scan of the pelvis. The treatment was considered unsuccessful in the event of periprosthetic joint infection (PJI) or aseptic loosening (AL) with need for explantation of the custom-made acetabular implant. RESULTS: The average follow-up was 41.9 ± 34.8 months (range 1.5-120). Implant survival at last follow-up was 75.7% (53 of 70). Explantation was necessary in 17 cases (15 PJI; 2 AL). Previous PJI as reason for RTHA (p= 0.025; OR 3.56 (95% CI: 1.14; 11.21)), additional revision of femoral components (p= 0.003; OR 8.4 (95% CI: 1.75; 40.42)), rheumatoid disease (p= 0.039; OR 3.43 (95% CI: 1.01; 11.40)), elevated preoperative CRP > 15.2 mg/l (p= 0.015; AUC: 0.7) and preoperative haemoglobin < 10.05 (p= 0.022; AUC: 0.69) were statistically significant risk factors associated with treatment failure. Age and BMI were not statistically significant contributing to implant failure. CONCLUSION: Risk factors for treatment failure were a previous PJI, additional revision of femoral component, rheumatoid disease, elevated preoperative CRP and low preoperative haemoglobin. Awareness of these risk factors will help to improve future treatment standards.

The psychological burden of a two-stage exchange of infected total hip and knee arthroplasties.

Infection is one of the most challenging complications after total joint arthroplasties affecting up to 30,000 patients in the US per year. This study investigates the psycho-social burden induced by the two-stage intervention in infected hip or knee replacements. All patients were treated with a two-stage exchange and were assessed at three different timepoints regarding their psychological conditions. Our findings suggest that psychological sequelae after treatment of periprosthetic joint infection are clearly underestimated in the literature and psychological correlates and side effects should be further highlighted during the training process of young surgeons.

sCD28, sCD80, sCTLA-4, and sBTLA Are Promising Markers in Diagnostic and Therapeutic Approaches for Aseptic Loosening and Periprosthetic Joint Infection.

Aseptic prosthetic loosening and periprosthetic joint infections (PJI) are among the most frequent complications after total knee/hip joint arthroplasty (TJA). Current research efforts focus on understanding the involvement of the immune system in these frequent complications. Different immune cell types have already been implicated in aseptic prosthetic loosening and PJI. The aim of this study was to systematically analyze aspirates from knee and hip joints, evaluating the qualitative and quantitative composition of soluble immunoregulatory markers, with a focus on co-inhibitory and co-stimulatory markers. It has been shown that these molecules play important roles in immune regulation in cancer and chronic infectious diseases, but they have not been investigated in the context of joint replacement. For this purpose, aspirates from control joints (i.e., native joints without implanted prostheses), joints with TJA (no signs of infection or aseptic loosening), joints with aseptic implant failure (AIF; i.e., aseptic loosening), and joints with PJI were collected. Fourteen soluble immunoregulatory markers were assessed using bead-based multiplex assays. In this study, it could be shown that the concentrations of the analyzed immunoregulatory molecules vary between control, TJA, AIF, and PJI joints. Comparing TJA patients to CO patients, sCD80 was significantly elevated. The marker sBTLA was significantly elevated in AIF joints compared to TJA joints. In addition, a significant difference for eight markers could be shown when comparing the AIF and CO groups (sCD27, sCTLA-4, sCD137, sCD80, sCD28, sTIM-3, sPD-1, sBTLA). A significant difference was also reached for nine soluble markers when the PJI and CO groups were compared (sLAG-3, sCTLA-4, sCD27, sCD80, sCD28, sTIM-3, sPD-1, IDO, sBTLA). In summary, the analyzed immunoregulatory markers could be useful for diagnostic purposes as well as to develop new therapeutic approaches for AIF and PJI.