Is combining massive bone allograft with free vascularized fibular flap the children's reconstruction answer to lower limb defects following bone tumour resection?

SummaryPurpose of the studyBone tumours are frequent conditions in children, and their surgical resection may lead to extensive defects which reconstruction is often challenging. Indeed, local conditions do not promote bone healing, and the achieved surgical result requires to be life-lasting. Capanna suggested a reconstruction technique combining massive allograft and free vascularized fibular flap. The first one is intended to withstand mechanical stress, and the second one offers biological and vascular support to improve bone healing and prevent infections.Materiel and methodsWe report our experience with this technique when applied to the lower limb in a prospective study including seven children, with a mean follow-up of 44 months.ResultsBone healing was achieved by one single procedure in 85.7% of the cases, usually 7 months after surgery. Six out of seven patients achieved a final and long-lasting outcome, five of them following a simple surgical history. Partial weight-bearing was post-operatively allowed at about 2 months, full weight-bearing was initiated at about 5.5 months.DiscussionA low complication rate was reported despite the extent of the disease and the type of the surgical procedure. Capanna's combined reconstructive technique appears very efficient in the management of massive bone defects following tumour resection in children's lower limb.Level of evidenceLevel IV. Retrospective therapeutic study

Analysis of segmental residual growth after progressive bone lengthening in congenital lower limb deformity

SummaryIntroductionThe issue of prognosis in limb length discrepancy in children affected by congenital abnormality remains a subject of concern. Therapeutic strategy must take length prediction into account, to adapt equalization techniques and the timing of treatment. Initial prognosis, however, may need revising after completion of one or several surgical interventions on the pathologic limb. The aim of this study was to determine the different types of growth response that a bone segment can present after progressive lengthening in case of congenital limb length discrepancy.Materials and methodsA series of 114 bone lengthenings with external fixator, performed in 36 girls and 50 boys with congenital lower limb length discrepancy, was retrospectively analyzed. Bone segment growth rates were measured before lengthening, during the first year after frame removal and finally over long-term follow-up, calculating the ratios of radiological bone length to the number of months between two measurements. Mean follow-up was 4.54±0.2 years.ResultsChanges in short- and long-term growth rate distinguished five patterns of bone behavior after lengthening, ranging from growth acceleration to total inhibition.DiscussionThese five residual growth patterns depended on certain factors causing acceleration or, on the contrary, slowing down of growth: age at the lengthening operation, percentage lengthening, and minimal period between two lengthenings. These criteria help optimize conditions for resumed growth after progressive segmental lengthening, avoiding conditions liable to induce slowing down or inhibition, and providing a planning aid in multi-step lengthening programs.Level of evidenceLevel IV. Retrospective study

Mac Cune-Albright syndrome. Answer to the e-quid “Painful lameness in a child”

International audienc

Status and perspectives of SARNET network

43 organisations (research, universities, industry, utilities, safety authorities and TSO) from 22 countries network their capabilities for R&D on Severe Accidents (SA) in SARNET (Severe Accident Research NETwork of excellence) in the EC FP7 for 4 years from April 2009. The overall work represents about 40 persons per year (230 researchers and 20 PhD students). A 43rd partner is currently joining the network: BARC (India). See www.sar-net.e

Proposed relation between SARNET network on severe accidents and TWG Gen.II/III

SA Research Priorities defined in SARNET network should be the basis for proposing in the future relevant R&D programs to address them, when needed, and launch projects with the endorsement of TWG

CoreSOAR Core Degradation State-of-the Art Report Update: Conclusions [in press]

In 1991 the CSNI published the first State-of-the-Art Report on In-Vessel Core Degradation, which was updated to 1995 under the EC 3rd Framework programme. These covered phenomena, experimental programmes, material data, main modelling codes, code assessments, identification of modelling needs, and conclusions including the needs for further research. This knowledge was fundamental to such safety issues as in-vessel melt retention of the core, recovery of the core by water reflood, hydrogen generation and fission product release. In the last 20 years, there has been much progress in understanding, with major experimental series finished, e.g. the integral in-reactor Phébus FP tests, while others have many tests completed, e.g. the electrically-heated QUENCH series on reflooding degraded rod bundles, and one test using a debris bed. The small-scale PRELUDE/PEARL experiments study debris bed quench, while LIVE examines melt pool behaviour in the lower head using simulant materials. The integral severe accident modelling codes, such as MELCOR and MAAP (USA) and ASTEC (Europe), encapsulate current knowledge in a quantitative way. After two EC-funded projects on the SARNET network of excellence, continued in NUGENIA, it is timely to take stock of the vast range of knowledge and technical improvements gained in the experimental and modelling areas. The CoreSOAR project, in NUGENIA/SARNET, drew together the experience of 11 European partners to update the state of the art in core degradation, finishing at the end of 2018. The review covered knowledge of phenomena, available integral experiments, separate-effects data, modelling codes and code validation, then drawing overall conclusions and identifying needs for further research. The final report serves as a reference for current and future research programmes concerning core degradation in NUGENIA, in other EC research projects such as in Horizon2020 and for projects under the auspices of OECD/NEA/CSNI

The role of the periosteal sleeve in the reconstruction of bone defects using a non-vascularised fibula graft in the pediatric population

Following resection of large benign bone tumors surgeons are confronted with bone defects severely affecting the stability of a limb. To restore the mechanical continuity of the bone different treatment methods using bone grafts have been described. In pediatric patients the thick periosteal sleeve is thought to contribute to bone formation

Influence of lengthening on the residual limb growth

Prognosis of limb length discrepancy in children affected by congenital abnormality remains a subject of concern. Therapeutic strategy must take length prediction into account in order to adapt equalization techniques and the timing of treatment. Initial prognosis, however, may need revising after completion of one or several surgical interventions on the pathologic limb. The aim of this study was to determine different types of growth response that a bone segment can present after progressive lengthening in case of congenital limb length discrepancy. Materials and methods. Treatment results were analyzed in 150 patients with congenital lower limb length discrepancy, who underwent surgery at age from 2 to 15 years old. Bone segment growth rates were measured before lengthening, during the first year after frame removal and, finally, over long-term follow-up, calculating the ratios of radiological bone length to the number of months between two measurements. Mean follow-up was 5.1±1.3 years. Results. Changes in short- and long-term growth rate distinguished five patterns of bone behavior after lengthening, ranging from growth acceleration to total inhibition. Discussion and Conclusion. These five residual growth patterns depended on certain factors causing acceleration or, on the contrary, slowing down of growth: age at the lengthening surgery, percentage of lengthening and minimal period between two lengthenings. These criteria help to optimize conditions for resumed growth after progressive segmental lengthening, avoiding conditions liable to induce slowing down or inhibition, and providing a planning aid in multi-step lengthening programs. Keywords: Congenital lower limb length discrepancy, bone lengthening, residual growt

The anatomical basis for anterior interosseous nerve palsy secondary to supracondylar humerus fractures in children

SummaryIntroductionVarious studies have found that 6.6 to 31% of supracondylar elbow fractures in children have nerve-related complications. One-third of these are cases of anterior interosseous nerve (AIN) palsy that usually result in a deficit of active thumb and index flexion. The goal of this cadaver study was to describe the course of the AIN to achieve a better understanding of how it may get injured.Materials and methodsOn 35 cadaver specimens, the median nerve and its collateral branches destined to muscles were dissected at the elbow and forearm levels. The distance at which the various branches arose was measured relative to the humeral intercondylar line. Interfascicular dissection of the AIN was used to map its distribution within the median nerve.ResultsThe AIN arises at an average of 45mm from the humeral intercondylar line. Before emerging from the median nerve, the AIN fascicles were always found in the dorsal part of the median nerve. After emerging, the AIN was divided into two zones. Zone 1 was the transitional portion from its exit point until its entrance into the interosseous space, where it changes direction. Zone 2 was the interosseous portion between the radius and ulna that comes into contact with the anterior interosseous membrane to which it is attached over its entire length until it ends in the pronator quadratus (PQ) muscle. The muscle branches of the AIN destined for the flexor pollicis longus (FPL) and flexor digitorum profundus (FDP) muscles mostly originated in Zone 1, which is the transitional portion between the median nerve and the fixed Zone 2. The branches destined to the pronator teres (PT) and flexor carpi radialis (FCR) originating from the median nerve are more proximal and superficial.DiscussionThe injury mechanisms leading to selective AIN palsy secondary to supracondylar elbow fracture in children are probably the result of two factors: direct contusion of the posterior aspect of the median nerve, and thereby the AIN fascicles, by the proximal fragment; stretching of AIN in Zone 1, which has less ability to withstand stretching than the median nerve and its other branches because the AIN is fixed in Zone 2.ConclusionDetails about the origin and course of the AIN can explain the high percentage of AIN palsy in supracondylar elbow fractures in children.Level of evidenceLevel IV. Anatomic study

Electrochemical Determination of Oxidic Melt Diffusion Coefficients

International audienceThe chemical diffusion coefficient of electroactive species such as Fe3+ and Ce4+ in silicate melts have been measured using an electrochemical technique: square wave voltametry. The experiments are conducted in an induction furnace in which three electrodes (made of platinum or iridium) are inserted in the crucible containing the melt. The technique has been improved to reduce the uncertainties due to the presence of a meniscus on the electrodes. Experimental results have been obtained at temperatures up to 1560 °C. The technique has proven its ability to analyze melts containing several electroactive species. These experimental results are compared to data from the literature