Sensitivity and specificity of standardised allergen extracts in skin prick test for diagnoses of IgE-mediated respiratory allergies

Abstract Background Skin prick tests (SPTs) are essential for the diagnosis of IgE-mediated allergy and are influenced by extract quality, biological potency and concentration of allergen. Methods In this open multicentre study 431 patients, aged 18–64 years were enrolled. Patients had a history of IgE-mediated allergy and a sensitisation (previous positive SPT of any manufacturer) against at least one of the investigated allergens: 6-grass pollen, house dust mite, birch and mugwort pollen. In our study, these allergens were tested in five concentrations each. To establish the optimal trade-off between sensitivity and specificity, the area under the receiver operating characteristic (ROC) curve was estimated by comparing the outcome of the SPT with three methods referred to as ‘reference methods’ (specific IgE, clinical case history and a previous SPT). Results For all allergens and reference methods, the area under the ROC curves were highly significant (p < 0.001). Specific IgE reference method resulted in the largest area under the curve (AUC) for all allergens (0.80–0.90) followed by previous SPT (0.70–0.87) and case history (0.65–0.74). Sensitivity of SPT increased with increasing concentration and specificity decreased. For all allergens, compared to specific IgE, the highest sensitivity (specificity at least 80%) was observed for the SPT solution of 50,000 Standardised Units (SU)/mL (grass pollen, birch pollen, house dust mite and mugwort). Conclusion In this study, with a large number of patients, it was demonstrated that clinical case history, previous SPT and specific IgE measurement could all be used as reference methods for the assessment of sensitivity/specificity of SPT solutions. The comparison of SPT with specific IgE resulted in the largest AUC. The highest sensitivity was observed for the SPT solution of 50,000 SU/mL. Trial registration EudraCT: 2006-005304-14

Correspondence (letter to the editor): Adjuvant Radiotherapy

No abstract available

Combinations of hydrogels and mesenchymal stromal cells (MSCs) for cartilage tissue engineering — a review of the literature

Cartilage offers limited regenerative capacity. Cell-based approaches have emerged as a promising alternative in the treatment of cartilage defects and osteoarthritis. Due to their easy accessibility, abundancy, and chondrogenic potential mesenchymal stromal cells (MSCs) offer an attractive cell source. MSCs are often combined with natural or synthetic hydrogels providing tunable biocompatibility, biodegradability, and enhanced cell functionality. In this review, we focused on the different advantages and disadvantages of various natural, synthetic, and modified hydrogels. We examined the different combinations of MSC-subpopulations and hydrogels used for cartilage engineering in preclinical and clinical studies and reviewed the effects of added growth factors or gene transfer on chondrogenesis in MSC-laden hydrogels. The aim of this review is to add to the understanding of the disadvantages and advantages of various combinations of MSC-subpopulations, growth factors, gene transfers, and hydrogels in cartilage engineering

Evaluation of implant fit and frontal plane alignment after bi-compartmental knee arthroplasty using patient-specific instruments and implants

Introduction The goals of successful bi-compartmental knee arthroplasty are to achieve correct fit and positioning of the implant, while appropriately correcting the mechanical alignment of the leg after surgery. As these requirements are not always reliably fulfilled using off-the-shelf implant systems, newer approaches for bi-compartmental resurfacing have been explored. Material and methods In this article we report the radiographic results of 30 patients with anteromedial osteoarthritis (OA) who were treated with a novel patient-specific fixed-bearing bi-compartmental knee resurfacing system using custom-made implants and instruments. Utilizing standardized pre- and postoperative radiographic analyses (based on anterior-posterior and lateral, anterior-posterior weight-bearing full-length radiographs, patella skyline views and preoperative computed tomography (CT) scanning) implant fit and positioning as well as correction of the mechanical axis (hip-knee-ankle angle, HKA) were determined. Results On average, HKA was corrected from 173.4 ±3.47° preoperatively to 179.4 ±2.85° postoperatively. The coronal femoro-tibial angle was corrected on average 5.61°. The preoperative tibial slope measured on lateral views was 6.38 ±2.4°, while the average slope in the CT-based planning protocol (iView) was 6.14 ±2.40°. Postoperative lateral tibial slope was determined to be 5.77 ±1.97°. The thickness of the posterior femoral cuts was measured intraoperatively and, in all cases, corresponded well to the targeted thickness of the cuts provided by the iView. The joint line was preserved in all cases and the average Insall-Salvati index was 1.078 ±0.11 pre- and 1.072 ±0.11 postoperatively. The fit of the implant components measured by over- or underhang was excellent throughout (< 1.01 mm). Conclusions Custom-made bicompartmental knee arthroplasty can ensure optimized fitting and positioning of the implant with restoration of the leg axis. These implants could be considered as an alternative primary solution for knee surgeons treating bi-compartmental disease

Acetabular Revision With Intramedullary and Extramedullary Iliac Fixation for Pelvic Discontinuity

Background: Parallel to the increase in revision hip procedures surgeons face more and more complex anatomical challenges with pelvic discontinuity (PD) being one of the worst-case scenarios. Here we report on our clinical results using an asymmetric acetabular component for the treatment of PD. The implant is armed in a monoblock fashion with an extramedullary iliac flange and provides the possibility to augment it with an intramedullary iliac press-fit stem. Methods: In a single-center retrospective cohort study we analyzed prospectively collected data of 49 patients (35 female, 14 male) suffering from unilateral periprosthetic PD treated with an asymmetric acetabular component between 2009 and 2017. The mean follow-up was 71 months (21-114). Complications were documented and radiographic and functional outcomes were assessed. Results: Kaplan-Meier analysis revealed a 5-year implant survival of 91% (confidence interval 77%-96%). The 5-year survival with revision for any cause was 87% (CI 74%-94%). The overall revision rate was 16% (n = 8). Two patients required acetabular component revision due to aseptic loosening. Four patients (8%) suffered from periprosthetic infection: one patient was treated with a 2-stage revision, and another one with resection arthroplasty. The other 2 patients were treated with debridement, irrigation, and exchange of the mobile parts. Of 6 patients (12%) suffering from hip dislocation, 2 required implantation of a dual mobility acetabular component. The mean Harris Hip Score improved from 41 preoperatively to 79 at the latest follow-up (P < .001). Conclusion: Our findings demonstrate that an asymmetric acetabular component with extramedullary and optional intramedullary iliac fixation is a reliable and safe treatment method for periprosthetic PD resulting in good clinical and radiographic mid-term results.</p

Revision of unicompartmental knee arthroplasty using the in situ referencing technique (Revision des unikompartimentellen Kniegelenkersatzes mit der In-situ-Referenzierungstechnik)

Objective: Revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) with the in situ referencing technique aiming to preserve as much ligament function and epi-metaphyseal bone stock as possible. Indications: Aseptic loosening, progression of osteoarthritis, periprosthetic fracture, periprosthetic infection, arthrofibrosis, polyethylene wear, malalignment, instability, femoro-tibial impingement. Contraindications: Unexplained pain, localized or systemic active infection (anywhere). Surgical technique: Referencing for the tibia and the femur cuts is performed prior to implant removal. The tibial cutting jig and the initial tibial resection level is set in a way that the sawblade just fits under the tibial implant. In case too much bone needs to be removed to achieve flush implant sitting on both the medial and lateral tibia, a step cut needs to be performed to build up the medial defect with an augment. Prior to femoral component removal, rotational alignment is determined and intramedullary referencing for the distal femur osteotomy is performed. Level of constraint and additional tibial stem fixation is chosen according to the amount of bone resected and according to ligament stability. Postoperative management: Sterile dressings and elastic compression bandaging. No limitation of active/passive range of motion. Full weight-bearing or partial weight-bearing for 2 weeks postoperatively in the presence of bone or soft tissue defects. Results: Between 2008 and 2019, 84 patients underwent revision of unicompartmental knee arthroplasty. The mean follow-up was 64 months (range 3–132 months). Implant survival after revision of UKA to TKA was 92% (95% CI = 82–97%) at 5 years of follow-up and 86% (95% CI = 69–93%) at 10 years of follow-up. The mean Oxford knee score was 20.1 (6–39, SD ± 6.5) preoperatively and 30.2 (3–48, SD ± 11.3) postoperatively. The mean visual analogue scale was 6.9 (range 1–10, SD ± 1.8) preoperatively and 3.9 (range 0–9, SD ± 2.6) postoperatively.</p

Recombinant human bone morphogenetic protein 7 exerts osteo-catabolic effects on bone grafts that outweigh its osteo-anabolic capacity

This study aimed to investigate the effects of recombinant human bone morphogenetic protein (rhBMP-7) on human cancellous bone grafts (BGs) while differentiating between anabolic and catabolic events. Human BGs alone or supplemented with rhBMP-7 were harvested 14 weeks after subcutaneous implantation into NOD/Scid mice, and studied via micro-CT, histomorphometry, immunohistochemistry and flow cytometry. Immunohistochemical staining for human-specific proteins made it possible to differentiate between grafted human bone and newly formed murine bone. Only BGs implanted with rhBMP-7 formed an ossicle containing a functional hematopoietic compartment. The total ossicle volume in the BMP+ group was higher than in the BMP- group (835 mm(3) vs. 365 mm(3), respectively, p < 0.001). The BMP+ group showed larger BM spaces (0.47 mm vs. 0.28 mm, p = 0.002) and lower bone volume-to-total volume ratio (31% vs. 47%, p = 0.002). Immunohistochemical staining for human-specific proteins confirmed a higher ratio of newly formed bone area (murine) to total area (0.12 vs. 0.001, p < 0.001) in the BMP+ group, while the ratio of grafted bone (human) area to total area was smaller (0.14 vs. 0.34, p = 0.004). The results demonstrate that rhBMP-7 induces BG resorption at a higher rate than new bone formation while creating a haematopoietic niche. Clinicians therefore need to consider the net catabolic effect when rhBMP-7 is used with BGs. Overall, this model indicates its promising application to further decipher BMPs action on BGs and its potential in complex bone tissue regeneration

Revision Arthroplasty Through the Direct Anterior Approach Using an Asymmetric Acetabular Component

Despite increasing numbers of primary hip arthroplasties performed through the direct anterior approach (DAA), there is a lack of literature on DAA revision arthroplasty. The present study was performed in order to evaluate outcomes and revision rates after revision through the DAA using an asymmetric acetabular component with optional intra- and extramedullary fixation. In a retrospective cohort study, we analyzed prospectively collected data of 57 patients (61 hips, 43 female, 18 male) who underwent aseptic acetabular component revision through the DAA with the abovementioned implant system between January 2015 and December 2017. The mean follow-up was 40 months (12–56). Survival rates were estimated using the Kaplan–Meier method. All complications were documented and functional outcomes were assessed pre- and postoperatively. Kaplan–Meier analysis revealed an estimated five-year implant survival of 97% (confidence interval CI 87–99%). The estimated five-year survival with revision for any cause was 93% (CI 83–98%). The overall revision rate was 6.6% (n = 4). Two patients had to undergo revision due to periprosthetic infection (3.3%). In one patient, the acetabular component was revised due to aseptic loosening four months postoperatively. Another patient suffered from postoperative iliopsoas impingement and was treated successfully by arthroscopic iliopsoas tenotomy. Two (3.3%) of the revised hips dislocated postoperatively. The mean Harris Hip Score improved from 35 (2–66) preoperatively to 86 (38–100) postoperatively (p < 0.001). The hip joint’s anatomical center of rotation was restored at a high degree of accuracy. Our findings demonstrate that acetabular revision arthroplasty through the DAA using an asymmetric acetabular component with optional intra- and extramedullary fixation is safe and practicable, resulting in good radiographic and clinical midterm results