Consolidation of massive bone allografts in limb-preserving operations for bone tumours

This study analysed the influence of several factors affecting the consolidation time of 83 massive bone allografts in 79 patients with malignant bone tumours: osteosarcoma 57; Ewing's sarcoma 8; malignant fibrous histiocytoma 3; chondrosarcoma 4; fibrosarcoma 5; and giant cell tumours 2. The mean age of the patients was 19 years and the mean length of the allografts was 18 cm. The minimum follow up was for 12 months. The mean consolidation time for metaphyseal and diaphyseal osteotomies was 6.5 and 16 months respectively. Fifteen diaphyseal osteotomies required autologous cancellous grafting. There were 8 allograft fractures after consolidation. The following factors which might influence consolidation were analysed: age of the host and donor; allograft length and site; type of osteotomy and osteosynthesis; intra-arterial and systemic chemotherapy; intraoperative and external radio-therapy. In diaphyseal osteotomies there were statistically significant differences in consolidation time with the use of systemic chemotherapy, external radiotherapy and the recipient's age

Measurement of bone lengthening forres; an experimental model in the lamb

To obtain the mechanical behaviour pattern of the lengthening process. DESIGN. IN VIVO: measurement of forces during bone engthening in lambs. BACKGROUND: A series of parameters of a mechanical and biological nature have a bearing on all lengthening processes, and most of them are not fully understood. METHODS: A strain-gauge-monitored unilateral fixator was designed and used to obtain data about the changes which took place in the forces of elongation at a rate of 1 mm/day in four lambs while a 3 cm progressive lengthening of the left tibia was being performed, analysing how these forces behaved from day to day, and how they changed in the course of a single day. RESULTS: The maximum forces in all the animals each day occur after distraction, and the forces reach their greatest magnitude between days 21 and 25 after surgery, attaining values of slightly over 8 kg (40-50% of the animal's weight). The maximum daily force starts to drop 1 h after distraction, and continues to decrease gradually throughout the day until it reaches a value slightly greater than the initial force on the previous day. CONCLUSION: This pattern is due to the distraction of soft tissues which gradually adapt to their new situation, thereby reducing the level of stress. RELEVANCE: In the daily bone lengthening procedure, the greatest forces are produced in a short period of time immediately after lengthening. they could be reduced to decrease pain in the patient and loads on the device by performing lengthening over a greater number of steps or using dynamic equipment able to absorb these forces

Empleo de aloinjerto óseo en la reparación quirúrgica de fracturas del platillo tibial

Cada vez es mayor el número de indicaciones posibles en el uso de aloinjertos en patología osteoarticular. Muchas veces supone una alternativa válida frente al uso de autoinjerto, evitando así la morbilidad que conlleva la extracción del injerto del propio paciente. Presentamos 6 casos de frac tura de platillo tibial externo en las que existía depresión central y hundimiento de la superficie articular (tipo B3 según la clasificación AO) en cuyo tratamiento quirúrgico se ha utilizado el injerto óseo de banco (fragmento de cabeza femoral tallada a medida) para el soporte del platillo tibial deprimido una vez levantado y conseguida la congruencia articular. En todos los casos se obtuvo un resultado satisfactorio en cuanto a la función de soporte y a la consolidación sin existir complicaciones per o postoperatorias

Natural fibers as an alternative of reinforcement in composite materials. a review.

 Actualmente, existe la necesidad en todo el mundo, de crear nuevos materiales que sean amigables con el medio ambiente, para ser reemplazados por aquellos en donde la naturaleza requiere de tiempos de descomposición elevados.  En este contexto, las fibras naturales se presentan como una alternativa de material para el consumo en la fabricación de partes industriales, principalmente por su bajo costo, menor peso y un consumo de energía inferior durante la fase producción, frente a las fibras sintéticas.  Por tanto, en el siguiente documento se presenta una revisión, sobre las propiedades más relevantes de las fibras naturales para utilizadas como refuerzo en materiales compuestos. Se destaca inicialmente la estructura y clasificación de las fibras lignocelulosicas, luego las principales propiedades que se pueden determinar, posteriormente se concentra el estudio en las propiedades mecánicas, térmicas y morfológicas, plasmando los resultados obtenidos por diversos autores alrededor del mundo. Finalmente se hace una discusión sobre los resultados y las implicaciones de los mismos en la selección de la matriz polimérica y el proceso de fabricación de materiales compuestos. Palabras clave: estabilidad térmica, materiales compuestos, resistencia mecánica, morfología.

Aloinjertos en artrodesis vertebrales extensas

La cirugía de las deformidades, fracturas y tumores vertebrales requiere frecuentemente artrodesis amplias, lo cual conlleva la dificultad de obtener suficiente injerto óseo autólogo (particularmente en niños y en casos de deformidades paralíticas) y la necesidad de una segunda incisión, con el consiguiente aumento del tiempo quirúrgico y eventual morbilidad. Estudiamos 52 pacientes afectos de deformidades, fracturas o tumores vertebrales que fueron intervenidos mediante artrodesis vertebral extensa, en los que se utilizó aloinjerto de cabeza femoral como hueso esponjoso para aumentar la cantidad obtenida del propio lecho de artrodesis (estructuras posteriores). Además, en tres ocasiones se utilizó como injerto óseo intersomático un fragmento de cabeza femoral tallado a medida, realizándose una costotransversectomía para su colocación. El seguimiento fue entre 1 y 4 años. La única complicación observada fue la aparición de seromas de resolución espontánea en los 15 primeros casos. Posteriormente este problema se evitó con el lavado repetido del injerto, una vez triturado, con suero fisiológico caliente. En nuestra experiencia, la utilización de aloinjertos óseos permitió disminuir el tiempo quirúrgico de las intervenciones y a su vez evitar nuevas incisiones, sin reducir se las posibilidades de obtener una correcta artrodesis vertebral

Intra-articular injection of two different doses of autologous bone marrow mesenchymal stem cells versus hyaluronic acid in the treatment of knee osteoarthritis: long-term follow up of a multicenter randomized controlled clinical trial (phase I/II)

Background: Mesenchymal stromal cells (MSCs) are a promising option to treat knee osteoarthritis (OA). Their safety and usefulness have been reported in several short-term clinical trials but less information is available on the longterm efects of MSC in patients with osteoarthritis. We have evaluated patients included in our previous randomized clinical trial (CMM-ART, NCT02123368) to determine their long-term clinical efect. Materials: A phase I/II multicenter randomized clinical trial with active control was conducted between 2012 and 2014. Thirty patients diagnosed with knee OA were randomly assigned to Control group, intraarticularly administered hyaluronic acid alone, or to two treatment groups, hyaluronic acid together with 10×106 or 100×106 cultured autol‑ ogous bone marrow-derived MSCs (BM-MSCs), and followed up for 12 months. After a follow up of 4 years adverse efects and clinical evolution, assessed using VAS and WOMAC scorings are reported. Results: No adverse efects were reported after BM-MSCs administration or during the follow-up. BM-MSCs-adminis‑ tered patients improved according to VAS, median value (IQR) for Control, Low-dose and High-dose groups changed from 5 (3, 7), 7 (5, 8) and 6 (4, 8) to 7 (6, 7), 2 (2, 5) and 3 (3, 4), respectively at the end of follow up (Low-dose vs Control group, p=0.01; High-dose vs Control group, p=0.004). Patients receiving BM-MSCs also improved clinically accord‑ ing to WOMAC. Control group showed an increase median value of 4 points (−11;10) while Low-dose and Highdose groups exhibited values of −18 (−28;−9) and −10 (−21;−3) points, respectively (Low-dose vs Control group p=0.043). No clinical diferences between the BM-MSCs receiving groups were found. Conclusions: Single intraarticular injection of in vitro expanded autologous BM-MSCs is a safe and feasible proce‑ dure that results in long-term clinical and functional improvement of knee OA

High Diversity of vacA and cagA Helicobacter pylori Genotypes in Patients with and without Gastric Cancer

BACKGROUND: Helicobacter pylori is associated with chronic gastritis, peptic ulcers, and gastric cancer. The aim of this study was to assess the topographical distribution of H. pylori in the stomach as well as the vacA and cagA genotypes in patients with and without gastric cancer. METHODOLOGY/PRINCIPAL FINDINGS: Three gastric biopsies, from predetermined regions, were evaluated in 16 patients with gastric cancer and 14 patients with dyspeptic symptoms. From cancer patients, additional biopsy specimens were obtained from tumor centers and margins; among these samples, the presence of H. pylori vacA and cagA genotypes was evaluated. Positive H. pylori was 38% and 26% in biopsies obtained from the gastric cancer and non-cancer groups, respectively (p = 0.008), and 36% in tumor sites. In cancer patients, we found a preferential distribution of H. pylori in the fundus and corpus, whereas, in the non-cancer group, the distribution was uniform (p = 0.003). A majority of the biopsies were simultaneously cagA gene-positive and -negative. The fundus and corpus demonstrated a higher positivity rate for the cagA gene in the non-cancer group (p = 0.036). A mixture of cagA gene sizes was also significantly more frequent in this group (p = 0.003). Ninety-two percent of all the subjects showed more than one vacA gene genotype; s1b and m1 vacA genotypes were predominantly found in the gastric cancer group. The highest vacA-genotype signal-sequence diversity was found in the corpus and 5 cm from tumor margins. CONCLUSION/SIGNIFICANCE: High H. pylori colonization diversity, along with the cagA gene, was found predominantly in the fundus and corpus of patients with gastric cancer. The genotype diversity observed across systematic whole-organ and tumor sampling was remarkable. We find that there is insufficient evidence to support the association of one isolate with a specific disease, due to the multistrain nature of H. pylori infection shown in this work

Experimental ovine toxoplasmosis: influence of the gestational stage on the clinical course, lesion development and parasite distribution

P. 1-14The relation between gestational age and foetal death risk in ovine toxoplasmosis is already known, but the mechanisms involved are not yet clear. In order to study how the stage of gestation influences these mechanisms, pregnant sheep of the same age and genetic background were orally dosed with 50 oocysts of Toxoplasma gondii (M4 isolate) at days 40 (G1), 90 (G2) and 120 (G3) of gestation. In each group, four animals were culled on the second, third and fourth week post infection (pi) in order to evaluate parasite load and distribution, and lesions in target organs. Ewes from G1 showed a longer period of hyperthermia than the other groups. Abortions occurred in all groups. While in G2 they were more frequent during the acute phase of the disease, in G3 they mainly occurred after day 20 pi. After challenge, parasite and lesions in the placentas and foetuses were detected from day 19 pi in G3 while in G2 or G1 they were only detected at day 26 pi. However, after initial detection at day 19 pi, parasite burden, measured through RT-PCR, in placenta or foetus of G3 did not increase significantly and, at in the third week pi it was lower than that measured in foetal liver or placenta from G1 to G3 respectively. These results show that the period of gestation clearly influences the parasite multiplication and development of lesions in the placenta and foetus and, as a consequence, the clinical course in ovine toxoplasmosis.S