Investigation of the pathogen-specific antibody response in periprosthetic joint infection.

PURPOSE: Periprosthetic joint infections (PJIs) are a very demanding complication of arthroplasty. Diagnosis of PJI and pathogen identification pose considerable challenges in clinical practice. We hypothesized that the pathogen-specific immune response to PJI reflects the infection process, provides clinically relevant information on disease course, and has the potential to further optimize antimicrobial therapy. METHODS: We conducted a prospective matched cohort pilot study with 13 patients undergoing two-stage septic revision arthroplasty (PJI patients) between 06/2020 and 06/2021, as well as 11 control patients undergoing one-stage aseptic revision arthroplasty (Non-PJI patients). Pre-, intra- and postoperative serum samples were collected at standardized time points. We developed a custom Luminex®-based quantitative bead-based suspension array (Infection Array; IA), and used it for simultaneous measurement of antibody specificities against 32 pathogens commonly associated with PJI in 267 serum samples. RESULTS: The IA was able to trace the dynamics of the pathogen-specific humoral immune response in all patients against PJI-related pathogens, prominently coagulase-negative staphylococci and streptococci. Pathogen-specific serum antibody titers declined in 62% of PJI patients over the course of treatment, while no changes in antibody titers were observed in 82% of Non-PJI patients during this study. Our serological data strongly suggested that antibody signatures reflect an immune response to microbial invasion. CONCLUSION: Our results provide insights into the pathophysiology of PJI and information on the individual disease courses. The IA is therefore a promising and novel serological tool of high resolution for monitoring the immunoproteomic footprints of infectious pathogens in the course of PJI.

Combined Application of Cold Physical Plasma and Chemotherapeutics against Chondrosarcoma Cells.

Chondrosarcoma (CS) is a rare malignant bone sarcoma that primarily affects cartilage cells in the femur and pelvis. While most subtypes exhibit slow growth with a very good prognosis, some aggressive subtypes have a poorer overall survival. CS is known for its resistance to chemotherapy and radiotherapy, leaving surgery as the sole effective therapeutic option. Cold physical plasma (CPP) has been explored in vitro as a potential therapy, demonstrating positive anti-tumor effects on CS cells. This study investigated the synergistic effects of combining CPP with cytostatics on CS cells. The chemotherapeutic agents cisplatin, doxorubicin, and vincristine were applied to two CS cell lines (CAL-78 and SW1353). After determining their IC20 and IC50, they were combined with CPP in both cell lines to assess their impact on the cell proliferation, viability, metabolism, and apoptosis. This combined approach significantly reduced the cell proliferation and viability while increasing the apoptosis signals compared to cytostatic therapy alone. The combination of CPP and chemotherapeutic drugs shows promise in targeting chemoresistant CS cells, potentially improving the prognosis for patients in clinical settings.

The role of different acetabular morphologies on patient-reported outcomes following periacetabular osteotomy in borderline hip dysplasia.

INTRODUCTION: The treatment option for borderline hip dysplasia (BHD) includes hip arthroscopy and periacetabular osteotomy (PAO). To the present day the controversial discussion remains, which intervention to prefer. Literature reports supporting an educated choice are scare, based on small patient cohorts and do not address the variability of acetabular morphology. Consequently, we intended to report PAO outcomes, from patients diagnosed with BHD, dependent on acetabular morphology, in a large patient cohort and aimed to define risk factors for poor clinical results and patient satisfaction. MATERIALS AND METHODS: A prospective monocentre study was conducted. Patients enrolled underwent PAO for symptomatic BHD (LCEA, 18°-25°). A total of 107 hips were included with 94 complete data sets were available for evaluation with a minimum follow-up of 1 year and a mean follow-up of 2.3 years. The mean age was 31 ± 8.2 years, and 81.3% were female. As the primary outcome measure, we utilized the modified Harris hip score (mHHS) with minimal clinically important change (MCID) of eight to define clinical failure. Results were compared after a comprehensive radiographic assessment distinguishing between lateral deficient vs. anterior/posterolateral deficient acetabular and stable vs. unstable hip joints. RESULTS: Overall, clinical success was achieved in 91.5% of patients and the mHHS improved significantly (52 vs. 84.7, p < 0.001). Eight hips failed to achieve the MCID and four had radiographic signs of overcorrection. Comparing variable joint morphologies, the rate of clinical success was higher in patients with an anterior/posterolateral deficient acetabular covarage compared to lateral deficient acetabular (95.2% vs. 90.4%). tThe highest rate of clinical failure was recorded in unstable hip joints (85.7% vs. 92.5% in stable hips). CONCLUSIONS: This study demonstrates that PAO is an effective means to treat symptomatic BHD with variable acetabular morphologies, achieving a clinical success in 91.5% of all patients. To maintain a high level of safety and patient satisfaction technical accuracy appears crucial.

Enhancing the Impact of Chemotherapy on Ewing Sarcoma Cells through Combination with Cold Physical Plasma.

Although Ewing's sarcoma (ES) is a rare, but very aggressive tumor disease affecting the musculoskeletal system, especially in children, it is very aggressive and difficult to treat. Although medical advances and the establishment of chemotherapy represent a turning point in the treatment of ES, resistance to chemotherapy, and its side effects, continue to be problems. New treatment methods such as the application of cold physical plasma (CPP) are considered potential supporting tools since CPP is an exogenous source of reactive oxygen and nitrogen species, which have similar mechanisms of action in the tumor cells as chemotherapy. This study aims to investigate the synergistic effects of CPP and commonly used cytostatic chemotherapeutics on ES cells. The chemotherapy drugs doxorubicin and vincristine, the most commonly used in the treatment of ES, were applied to two different ES cell lines (RD-ES and A673) and their IC20 and IC50 were determined. In addition, individual chemotherapeutics in combination with CPP were applied to the ES cells and the effects on cell growth, cell viability, and apoptosis processes were examined. A single CPP treatment resulted in the dose-dependent growth inhibition of ES cells. The combination of different cytostatics and CPP led to significant growth inhibition, a reduction in cell viability, and higher rates of apoptosis compared to cells not additionally exposed to CPP. The combination of CPP treatment and the application of cytostatic drugs to ES cells showed promising results, significantly enhancing the cytotoxic effects of chemotherapeutic agents. These preclinical in vitro data indicate that the use of CPP can enhance the efficacy of common cytostatic chemotherapeutics, and thus support the translation of CPP as an anti-tumor therapy in clinical routine.

Revision lateralization osteotomy of the tibial tubercle has excellent outcomes in patients suffering from previous medial tibial tubercle overcorrection.

INTRODUCTION: Tibial tubercle osteotomy (TTO) is a common procedure used to treat patients with patellofemoral instability (PFI) and osteoarthritis (PFOA). Medial patellar maltracking due to previous excessive medialization of the tibial tubercle has rarely been reported. Therefore, the goal of this study was to assess patient-reported outcome measures (PROMs) after revision osteotomy with lateralization of the tibial tubercle (RL-TTO) to correct medial patellofemoral maltracking. MATERIALS AND METHODS: Between 2017 and 2021, a series of 11 patients (male/female 1/10; age 35.8 ± 10.5 years) were treated by RL-TTO, of whom 8 patients could be retrospectively evaluated after a mean of 32.4 ± 15.1 months (range 18-61 months) postoperatively. The Kujala anterior knee pain scale, the patellofemoral subscale of the Knee Osteoarthritis and Outcome Score (KOOS-PF), and a numeric analog scale (NAS; 0-10) regarding anterior knee pain (AKP) at rest and during activity were assessed from pre- to postoperatively. RESULTS: The preoperative mean tibial tubercle-trochlear groove (TT-TG) and tibial tubercle-posterior cruciate ligament (TT-PCL) distances were - 6.5 ± 6.5 mm and 0.7 ± 4.6 mm, respectively. The intraoperatively determined amount of tibial tubercle lateralization averaged 10.7 ± 3.6 mm. The Kujala score and KOOS-PF improved significantly from 33.6 ± 10.1 (23-51) points to 94.4 ± 6.2 points (82-100) (p < 0.001) and from 20.6 ± 13.2 points (0-43.3) to 87.3 ± 9.9 points (72.8-100) (p < 0.001) from pre- to postoperatively, respectively. Pain at rest decreased from 5.8 ± 1.9 to 0.8 ± 0.9 (p < 0.001), and pain during activity decreased from 8.6 ± 1.3 to 1.6 ± 1.5 (p < 0.001). CONCLUSION: RL-TTO significantly improved subjective knee function and AKP in patients suffering from medial patellar maltracking due to previous excessive tibial tubercle medialization osteotomy at short-term follow-up.

Synchrotron-based characterization of arthroprosthetic CoCrMo particles in human bone marrow.

Particles released from cobalt-chromium-molybdenum (CoCrMo) alloys are considered common elicitors of chronic inflammatory adverse effects. There is a lack of data demonstrating particle numbers, size distribution and elemental composition of bone marrow resident particles which would allow for implementation of clinically relevant test strategies in bone marrow models at different degrees of exposure. The aim of this study was to investigate metal particle exposure in human periprosthetic bone marrow of three types of arthroplasty implants. Periprosthetic bone marrow sections from eight patients exposed to CoCrMo particles were analyzed via spatially resolved and synchrotron-based nanoscopic X-ray fluorescence imaging. These analyses revealed lognormal particle size distribution patterns predominantly towards the nanoscale. Analyses of particle numbers and normalization to bone marrow volume and bone marrow cell number indicated particle concentrations of up to 1 × 1011 particles/ml bone marrow or 2 × 104 particles/bone marrow cell, respectively. Analyses of elemental ratios of CoCrMo particles showed that particularly the particles' Co content depends on particle size. The obtained data point towards Co release from arthroprosthetic particles in the course of dealloying and degradation processes of larger particles within periprosthetic bone marrow. This is the first study providing data based on metal particle analyses to be used for future in vitro and in vivo studies of possible toxic effects in human bone marrow following exposure to arthroprosthetic CoCrMo particles of different concentration, size, and elemental composition. Graphical abstract.

Biocompatible Gas Plasma Treatment Affects Secretion Profiles but Not Osteogenic Differentiation in Patient-Derived Mesenchymal Stromal Cells.

Cold physical plasma (CPP), a partially ionized gas that simultaneously generates reactive oxygen and nitrogen species, is suggested to provide advantages in regenerative medicine. Intraoperative CPP therapy targeting pathologies related to diminished bone quality could be promising in orthopedic surgery. Assessment of a clinically approved plasma jet regarding cellular effects on primary bone marrow mesenchymal stromal cells (hBM-MSCs) from relevant arthroplasty patient cohorts is needed to establish CPP-based therapeutic approaches for bone regeneration. Thus, the aim of this study was to derive biocompatible doses of CPP and subsequent evaluation of human primary hBM-MSCs' osteogenic and immunomodulatory potential. Metabolic activity and cell proliferation were affected in a treatment-time-dependent manner. Morphometric high content imaging analyses revealed a decline in mitochondria and nuclei content and increased cytoskeletal compactness following CPP exposure. Employing a nontoxic exposure regime, investigation on osteogenic differentiation did not enhance osteogenic capacity of hBM-MSCs. Multiplex analysis of major hBM-MSC cytokines, chemokines and growth factors revealed an anti-inflammatory, promatrix-assembling and osteoclast-regulating secretion profile following CPP treatment and osteogenic stimulus. This study can be noted as the first in vitro study addressing the influence of CPP on hBM-MSCs from individual donors of an arthroplasty clientele.

Osteoarthrosis, Advanced Age, and Female Sex Are Risk Factors for Inferior Outcomes After Hip Arthroscopy and Labral Debridement for Femoroacetabular Impingement Syndrome: Case Series With Minimum 10-Year Follow-Up.

PURPOSE: (1) To determine the cumulative survivorship using the endpoint of total hip arthroplasty (THA) correlated with osteoarthrosis (Tönnis grade ≤ 1 vs Tönnis grade > 1) at a minimum 10-year follow-up and (2) to identify risk factors for THA conversion. METHODS: This study examined 112 patients who underwent hip arthroscopy for femoroacetabular impingement syndrome (FAIS) between 2007 and 2009. The inclusion criterion was primary hip arthroscopy to treat FAIS with corresponding chondrolabral pathologies. The exclusion criteria were secondary hip pathologies, revision hip arthroscopy, or dysplasia. The mean follow-up period was 11 years. Cumulative survival was estimated by Kaplan-Meier analysis using the endpoint of THA. Risk factors for THA conversion were identified using a multivariate Cox proportional hazards model. RESULTS: Forty patients underwent THA. The cumulative survivorship rate at 11 years was 86% for patients with a Tönnis grade of 1 or less and 46% for those with a Tönnis grade greater than 1. Osteoarthrosis, advanced age, and female sex were associated with lower hip survival rates. In particular, the risk of THA conversion was 24% higher for patients with an advanced age at the time of surgery, 97% higher for female patients, and 133% higher for hips with a Tönnis grade greater than 1. CONCLUSIONS: The survivorship rate at a mean 11-year follow-up after arthroscopic FAIS therapy was 86.3% in the group with a Tönnis grade of 1 or less and 46.4% in the group with a Tönnis grade greater than 1. The presence of osteoarthrosis, advanced age, and female sex adversely affected the outcome. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

[Hip-spine syndrome-current developments and state of the evidence]. / Hip-Spine-Syndrom ­ Aktuelle Entwicklungen und Evidenzlage.

The movements between the spine, pelvis and hip joints are coordinated to allow for a physiological balance of the upper body and the pelvis during sitting and standing. Degenerative changes or spondylodesis of the spine result in decreased pelvic mobility and can lead to increased rates of instability in the presence of total hip arthroplasty (THA). To reduce the risk of THA dislocation several authors have recently recommended functional radiographs of the spine and pelvis, as well as individual safe zones for THA components. The aim of this article is to summarize the current body of knowledge regarding the influence of spinopelvic alignment on THA and provide recommendations for everyday clinical practice.

Validation of Synovial Aspiration in Girdlestone Hips for Detection of Infection Persistence in Patients Undergoing 2-Stage Revision Total Hip Arthroplasty.

BACKGROUND: The aim of this study was to assess the diagnostic performance of synovial aspiration in Girdlestone hips, without a Polymethylmethacrylate (PMMA) spacer, for the detection of infection persistence before total hip arthroplasty (THA) reimplantation. METHODS: Seventy-four patients undergoing stage revision THA surgery were included in this retrospective cohort study. Both synovial cultures and serum C-reactive protein values were acquired before explantation of the THA and of the Girdlestone hip before reimplantation. RESULTS: The diagnostic performance of the synovial aspiration of the Girdlestone hip achieved a sensitivity of only 13% and a specificity of 98%. The determination of the serum C-reactive protein value for Girdlestone hips achieved a sensitivity of 95% and a specificity of only 20%. CONCLUSIONS: Our data show that the Girdlestone aspiration can neither reliably confirm nor exclude a persistence of infection.

Reduced rates of non-union with modified periacetabular osteotomy using peracetic-acid sterilized cancellous allografts.

The objective of the present study was to analyze the clinical and radiological results of periacetabular osteotomies (PAO) using Kirschner wire fixation and an allogeneic cancellous bone graft. This retrospective cohort study included 73 patients (85 PAOs). The allografts were processed from distal femur of cadaveric donors, defatted, sterilized with a peracetic-acid ethanol solution and freeze-dried. The clinical outcome, as measured by the Harris Hip Scores (HHS), the complication rate and the acetabular correction, as measured by radiological parameters, were compared. The postoperative femoral head coverage and HSS were significantly improved. Major complications occurred in five cases (6 %), but in no case did we observe a non-union or a graft-associated adverse effect. Fixation of the acetabular fragment with Kirschner wires in combination with an allogeneic cancellous bone graft is a safe method, with a low complication rate, no loss of correction and can prevent the occurrence of non-union with a high degree of probability.

Assessment of fatty degeneration of the gluteal muscles in patients with THA using MRI: reliability and accuracy of the Goutallier and quartile classification systems.

The purpose of this study was to quantify the performance of the Goutallier classification for assessing fatty degeneration of the gluteus muscles from magnetic resonance (MR) images and to compare its performance to a newly proposed system. Eighty-four hips with clinical signs of gluteal insufficiency and 50 hips from asymptomatic controls were analyzed using a standard classification system (Goutallier) and a new scoring system (Quartile). Interobserver reliability and intraobserver repeatability were determined, and accuracy was assessed by comparing readers' scores with quantitative estimates of the proportion of intramuscular fat based on MR signal intensities (gold standard). The existing Goutallier classification system and the new Quartile system performed equally well in assessing fatty degeneration of the gluteus muscles, both showing excellent levels of interrater and intrarater agreement. While the Goutallier classification system has the advantage of being widely known, the benefit of the Quartile system is that it is based on more clearly defined grades of fatty degeneration.

Implications for Femoral Tunnel Placement in Medial Patellofemoral Ligament Reconstruction Considering the Sagittal Trochlear Groove Curvature in Severe Trochlear Dysplasia Before and After Deepening Trochleoplasty.

BACKGROUND: Medial patellofemoral ligament reconstruction (MPFL-R) aims to restore proper ligament function with minimal changes in length during range of motion, yet the ideal area for femoral fixation of the graft remains controversial. PURPOSE: To determine the region where the isometric circular path of a simulated MPFL graft (best-fit circle) follows the sagittal radius curvature of the trochlea in normal (nontrochlear dysplastic) knees and to evaluate the best-fit circle coverage of different femoral fixation points in knees with severe trochlear dysplasia (TD) and after deepening trochleoplasty. STUDY DESIGN: Controlled laboratory study. METHODS: Twelve patients (4 male, 8 female; mean age, 24 ± 8 years) who underwent surgical treatment for recurrent lateral patellar instability due to severe TD were prospectively enrolled in this study. Four previously defined reference points for the femoral MPFL-R (Schöttle, Fujino, Stephen, and Oka) were identified, and the best-fit circle was drawn along the sagittal trochlear groove curvature. The divergence between each best-fit circle and the trochlear groove was calculated, with negative values indicating relative slackening and positive values indicating relative tightening of the simulated MPFL graft. Measurements were made on true-lateral fluoroscopic images before and after deepening trochleoplasty and compared with those of a sex-matched control group. RESULTS: The best-fit circle of the Schöttle point followed the sagittal curvature of the trochlea most closely in both the control and trochlear dysplastic knees, followed by the Fujino, Stephen, and Oka points. As the radius of the trochlear groove curvature increased, the divergence of all best-fit circles to the trochlear groove became negative (all P < .05). This effect was most pronounced at the Stephen and Oka points, followed by the Fujino and Schöttle points (all P < .05). After deepening trochleoplasty, the divergence of the Schöttle point changed toward positive values (11.6% at 40°; P < .001). Concurrently, the best-fit circle divergence of all other reference points improved toward baseline (all P < .05). CONCLUSION: The isometric circle of the Schöttle point provides the best congruence with the sagittal trochlear groove curvature in both the normal trochlea and the dysplastic trochlea. After trochleoplasty, the best-fit circles of more distal femoral fixation points resulted in better congruence with the deepened trochlear groove, whereas the best-fit circle of Schöttle indicated graft tension during flexion. CLINICAL RELEVANCE: According to the present study, different femoral fixation points should be considered depending on whether the TD is corrected.

Comparison of a Single Assessment Numeric Evaluation Method and the Banff Patella Instability Instrument 2.0 for Patients With Patellofemoral Instability.

Background: The concept of Single Assessment Numeric Evaluation (SANE) has been introduced for several clinical entities; however, a validated SANE focusing on patients with patellofemoral instability has not been described. Purpose/Hypothesis: The purpose of this study was to investigate the expressiveness of SANE questions (SQs) for the assessment of patients experiencing patellofemoral instability. It was hypothesized that the complexity of patellofemoral instability cannot be demonstrated by a single question. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: Between October 2022 and March 2023, 120 consecutive patients (male/female, 50/70; mean age, 23.9 ± 8.0 years; mean body mass index, 25.3 ± 5.1 kg/m2) with patellofemoral instability were assessed with the Banff Patella Instability Instrument 2.0 (BPII 2.0). Patients were randomized into 3 groups (40 patients each) and asked to answer 1 of 3 SQs: "How do you rate your knee joint if a completely stable kneecap means 100%?" (SQ 1), "How do you rate your knee joint if complete satisfaction means 100%?" (SQ 2), and "How do you rate your knee joint if complete normal function means 100%?" (SQ 3). Means ± standard deviations were compared using 1-way analysis of variance, the correlation between BPII 2.0 and each SQ was assessed by Pearson correlation, and Bland-Altmann analysis was performed to investigate biases of each SQ in comparison with BPII 2.0. Results: The mean BPII 2.0 score was 40.5 ± 16.8 points, and the mean results of SQ 1, SQ 2, and SQ 3 were 44.2% ± 26.0%, 42.6% ± 25.4%, and 44.2% ± 18.9%, respectively, without significant differences between the groups (all P > .05). The correlations between BPII 2.0 and SQ 1, SQ 2, and SQ 3 were high (r = 0.75; 95% CI, 0.58 to 0.86; P < .0001), low (r = 0.35; 95% CI, -0.05 to 0.6; P = .02), and low (r = 0.31; 95% CI, -0.002 to 0.56; P = .051), respectively. Bland-Altman analysis between BPII 2.0 and SQ 1, SQ 2, and SQ 3 revealed biases of -0.12 (SD, 17.1), -1.45 (SD, 24.4), and -8.0 (SD, 19.4), respectively. Conclusion: The SQ "How do you rate your knee joint if a completely stable kneecap means 100%?" demonstrated concurrent validity with the BPII 2.0 and may serve as a helpful tool to quickly assess patients with recurrent patellofemoral instability in a preoperative setting.

Cold Physical Plasma Reduces Motility of Various Bone Sarcoma Cells While Remodeling the Cytoskeleton.

BACKGROUND/AIM: Cold physical plasma (CPP) has emerged as an effective therapy in oncology by inducing cytotoxic effects in various cancer cells, including chondrosarcoma (CS), Ewing's sarcoma (ES), and osteosarcoma (OS). The current study investigated the impact of CPP on cell motility in CS (CAL-78), ES (A673), and OS (U2-OS) cell lines, focusing on the actin cytoskeleton. MATERIALS AND METHODS: The CASY Cell Counter and Analyzer was used to study cell proliferation and determine the optimal concentrations of fetal calf serum to maintain viability without stimulation of cell proliferation. CellTiter-BlueCell viability assay was used to determine the effects of CPP on the viability of bone sarcoma cells. The Radius assay was used to determine cell migration. Staining for Deoxyribonuclease I, G-actin, and F-actin was used to assay for the effects on the cytoskeleton. RESULTS: Reductions in cell viability and motility were observed across all cell lines following CPP treatment. CPP induced changes in the actin cytoskeleton, leading to decreased cell motility. CONCLUSION: CPP effectively reduces the motility of bone sarcoma cells by altering the actin cytoskeleton. These findings underscore CPP's potential as a therapeutic tool for bone sarcomas and highlight the need for further research in this area.

Factors Affecting Choice of Surgical Treatment of Cartilage Lesions of the Knee: An Analysis of Data From 5143 Patients From the German Cartilage Registry (KnorpelRegister DGOU).

Background: Symptomatic full-thickness cartilage lesions of the knee joint are considered an indication for cartilage repair surgery. Patient- and lesion-specific factors like age, nutritional status, etiology of defect, or integrity of corresponding joint surface remain controversial in indicating cartilage repair surgery. Furthermore, the selection of the most suitable cartilage repair technique for a specific cartilage lesion remains debatable. Purpose: To evaluate indications and choice of treatment method for cartilage repair surgery, depending on patient- and lesion-specific data from the German Cartilage Registry. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 6305 consecutive patients who underwent cartilage repair surgery of the knee evaluated and 5143 complete datasets were included in the analysis (follow-up rate, 81.5%). Patient-specific (age, body mass index, smoking status, previous operations, clinical leg axis) and lesion-specific (size, grading, location, etiology) data were provided by the attending surgeon at the time of surgery. Appropriate statistical tests were used to compare data depending on type and normality of data. Multivariable logistic regressions were calculated to investigate independent factors for the choice of specific cartilage repair techniques. Results: The median size of treated cartilage lesions was 3.6 cm2, and most defects were of degenerative origin (54.8%). Of the registered patients, 39.2% were categorized as overweight and 19.6% as obese, while 23.3% were smokers. The most prevalently documented operative techniques were the autologous chondrocyte implantation (ACI) (52.4%), bone marrow stimulation (BMS) (17.3%), and BMS augmented with collagen scaffolds (9.3%). Independent factors that made the use of ACI more likely were bigger lesion size, previous surgery at the joint, and lesions located at the trochlea or the patella. On the contrary, BMS or augmented BMS were preferred in older patients, with damaged corresponding joint surface, and with more concomitant surgeries. Conclusion: Cartilage repair surgery was indicated irrespective of nutritional status, smoking status, or etiology of the treated lesion. ACI was the most prevalent technique and was preferred for younger patients and patellar lesions. While older patients with degenerative changes to the joint were not excluded from cartilage repair surgery, the use of ACI was restricted.

Reconstruction of Paprosky IIIB acetabular defects with porous tantalum shells and augments using the footing technique.

Aims: The use of a porous metal shell supported by two augments with the 'footing' technique is one solution to manage Paprosky IIIB acetabular defects in revision total hip arthroplasty. The aim of this study was to assess the medium-term implant survival and radiological and clinical outcomes of this technique. Methods: We undertook a retrospective, two-centre series of 39 hips in 39 patients (15 male, 24 female) treated with the 'footing' technique for Paprosky IIIB acetabular defects between 2007 and 2020. The median age at the time of surgery was 64.4 years (interquartile range (IQR) 54.4 to 71.0). The median follow-up was 3.9 years (IQR 3.1 to 7.0). Results: The cumulative medium-term survival of the acetabular construct was 89%. Two hips (5.1%) required further revision due to shell loosening, one hip (2.6%) due to shell dislocation, and one hip (2.6%) due to infection. The median Harris Hip Score improved significantly from 47 points (IQR 41.5 to 54.9) preoperatively to 80 points (IQR 73.5 to 88.6) at the latest follow-up (p < 0.001). Conclusion: The reconstruction of Paprosky IIIB acetabular defects with porous tantalum shells and two augments using the 'footing' technique showed excellent medium-term results. It is a viable option for treating these challenging defects.

Effective combination of cold physical plasma and chemotherapy against Ewing sarcoma cells in vitro.

Ewing's sarcoma (ES) is the second most common bone tumor in children and adolescents and is highly malignant. Although the new chemotherapy has significantly improved the survival rate for ES from about 10 to 75%, the survival rate for metastatic tumors remains around 30%. This treatment is often associated with various side effects that contribute to the suffering of the patients. Cold physical plasma (CPP), whether used alone or in combination with current chemotherapy, is considered a promising adjunctive tool in cancer treatment. This study aims to investigate the synergistic effects of CPP in combination with cytostatic chemotherapeutic agents that are not part of current ES therapy. Two different ES cell lines, RD-ES and A673, were treated with the determined IC20 concentrations of the chemotherapeutic agents cisplatin and methotrexate (MTX) in combination with CPP. The effects on population doubling, cell viability, and apoptotic processes within these cell lines were assessed. This combination therapy has led to a reduction of population doubling and cell viability, as well as an increase in apoptotic activity in cells compared to CPP monotherapy. The results of this study provide evidence that combining CPP with non-common chemotherapy drugs such as MTX and CIS in the treatment of ES enhances the anticancer effects of these drugs. These findings open up new possibilities for the effective use of these drugs against ES.