Outcomes After Chevron Osteotomy with and Without Additional Akin Osteotomy: A Retrospective Comparative Study.

Background: Chevron osteotomy is one of the most common approaches to hallux valgus corrective surgery. This procedure is often combined with Akin osteotomy of the proximal phalanx of the hallux. There are no definitive guidelines specifying the indications for a given osteotomy technique nor data on postoperative loss of correction or the effect of the type of first-ray surgery on the development of adjacent-joint arthritis. The aim of this study was to assess radiographic treatment outcomes via chevron osteotomy with and without Akin osteotomy. Methods: The study evaluated 117 patients treated in the period 2016-2019. Ninety-nine of those patients underwent distal chevron osteotomy alone, and 18 patients underwent a combined chevron-Akin double osteotomy. The analyzed radiograms had been obtained preoperatively, at 6 weeks after surgery, and after a long-term follow-up. The following parameters were assessed: the intermetatarsal angle (IMA), hallux valgus angle (HVA), interphalangeal angle (IPA), postoperative recurrence of valgus deformity, adjacent-joint arthritis, and complications. Results: Chevron-Akin osteotomy helped maintain lower HVA and IPA values in long-term follow-up in comparison with those in the patients who underwent chevron osteotomy alone. The chevron osteotomy group showed a significant increase in the mean HVA from 18.37° at the first follow-up visit to 20.81° at the last follow-up visit. There were no differences between the groups in terms of the remaining assessed radiographic parameters. Hallux valgus surgery does not increase adjacent-joint arthritis. Conclusion: The use of combined chevron-Akin osteotomy does not affect HVA or IMA correction. The combination of chevron and Akin osteotomies reduces the risk of increased HVA and IPA in long-term follow-up. The additional Akin osteotomy does not increase the risk of adjacent-joint arthritis. Combining chevron osteotomy with Akin osteotomy is recommended in hallux valgus deformity correction.

The Epidemiology of Benign Proliferative Processes of the Skeletal System in Children.

A suspicion of a proliferative bone lesion in a child seems to be a major diagnostic problem for clinicians. There are no diagnostic and treatment algorithms described in the literature and no reliable cohort epidemiological data. Our study was conducted among 289 paediatric patients (0-18 years old) with an initial diagnosis of a bone tumour or tumour-like lesion. The study comprised a retrospective epidemiological analysis, an assessment of the concordance of the initial diagnoses with the histopathological diagnoses and an analysis of the specific locations of the various bone lesions. The results obtained have made it possible to formulate the following conclusions. (1) The most common proliferative bone lesion in children is osteochondroma; also common are fibrous dysplasia, non-ossifying fibromas and bone cysts. (2) Verifying the initial diagnosis by means of biopsy is essential. (3) Osteochondromas are typically located in the metaphyses of long bones, fibrous dysplasia in the femur and skull, cyst-like lesions in the proximal humerus and non-osteochondral fibromas exclusively in the lower limbs. What could improve the quality of treatment for children with primary proliferative bone diseases is the establishment of centres of paediatric orthopaedic oncology skilled in early diagnosis and prompt management.

The Global Registry for Hereditary Angioedema due to C1-Inhibitor Deficiency.

Hereditary angioedema (HAE) is a rare condition, mostly due to genetic deficiency of complement C1 inhibitor (C1-INH). The rarity of HAE impedes extensive data collection and assessment of the impact of certain factors known to affect the course of this disabling and life-threatening disease. Establishing a global registry could assist to overcome such issues and provides valuable patient data from different countries. The HAE Global Registry is a disease-specific registry, with web-based electronic support, where data are provided by physicians and patients through a dedicated application. We collected data between January 1, 2018, and August 31, 2020. Data on 1297 patients from 29 centers in 5 European countries were collected. At least one attack was recorded for 497 patients during the study period. Overall, 1182 patients were diagnosed with HAE type 1 and 115 with type 2. At the time of database lock, 389 patients were taking long-term prophylactic medication, 217 of which were on danazol. Most recorded attacks affected the abdomen, were generally moderate in severity, and occurred in patients who were not on prophylactic treatment (70.6%, 6244/8848). The median duration of attacks was 780 min (IQR 290-1740) in patients on prophylactic medication and 780 min (IQR 300-1920) in patients not on continuous prophylactic medication. In conclusion, the establishment of a registry for C1-INH-HAE allowed collection of a large amount of data that may help to better understand the clinical characteristics of this disease. This information may enhance patient care and guide future therapeutic decisions.

Analyzing stationary States of gene regulatory network using petri nets.

We introduce and formally define the notion of a stationary state for Petri nets. We also propose a fully automatic method for finding such states. The procedure makes use of the Presburger arithmetic to describe all the stationary states. Finally we apply this novel approach to find stationary states of a gene regulatory network describing the flower morphogenesis of A. thaliana. This shows that the proposed method can be successfully applied in the study of biological systems.

Analyzing stationary states of gene regulatory network using petri nets.

We introduce and formally define the notion of a stationary state for Petri nets. We also propose a fully automatic method for finding such states. The procedure makes use of the Presburger arithmetic to describe all the stationary states. Finally we apply this novel approach to find stationary states of a gene regulatory network describing the flower morphogenesis of A. thaliana. This shows that the proposed method can be successfully applied in the study of biological systems.