[Alloplastic material for bone substitution. Animal experiments and clinical study].
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The good results obtained with silicon implants used in the frontal region are reported by the authors. After the correct primary treatment the reconstructive operations have been performed at the least 6 months after the lesion, if the environment of the defect was free from any reaction during this time. 14 implantations have been performed in 2 years. Satisfactory functional and cosmetic results were obtained and the implant was to be removed in no case.
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Cialit preserved cartilage was used to fill defects of the bulla of porpoises and the histological healing was studied. Hyaline and elastic cartilage are showing an integration without reactions. The cartilage is resorbed consecutively by the recipient and substituted by bone. Whereas the hyaline cartilage shows a complete bony substitute and a small enlargement we can registrate that the elastic cartilage often shows a resorptive tendency with replacement of connective tissue and loss of the shape. The histological results are corresponding to the clinical results when using preserved cartilage in middle ear surgery for restoring the posterior wall.
PURPOSE: The choice of reconstructive material for orbital floor fractures remains a subject of debate. While autologous bone has historically been considered the "gold standard," alloplastic implants offer potential advantages in reducing surgical morbidity. This meta-analysis aimed to compare the safety and efficacy of autologous bone grafts versus alloplastic implants in orbital floor reconstruction. METHODS: A systematic review was conducted in accordance with PRISMA guidelines (PROSPERO: CRD420251140583). Electronic databases (PubMed, Scopus, Web of Science, Cochrane Library) were searched from inception to August 2025. Randomized controlled trials and comparative cohort studies evaluating functional outcomes (diplopia, enophthalmos) and complications (ectropion, infection, malposition) were included. Data were synthesized using a random-effects model, with risk ratios (RR) and 95% confidence intervals (CI) calculated. RESULTS: Twenty studies comprising 2,119 patients were included. Alloplastic implants demonstrated statistically significant superiority in periocular safety, with a reduced risk of postoperative ectropion compared to autologous grafts (RR = 2.245; p = 0.020). In an exploratory sensitivity analysis excluding one outlier study, autologous grafts were associated with a significantly higher risk of implant malposition (RR = 2.074; p = 0.004). Autologous reconstruction was associated with a strong trend toward increased postoperative pain (p = 0.052) and inherent donor-site morbidity. No statistically significant differences were observed regarding infection (p = 0.402), enophthalmos (p = 0.201), or diplopia (p = 0.221). CONCLUSION: Alloplastic implants were associated with a lower risk of ectropion and implant malposition, with functional outcomes statistically comparable to autologous bone. Given the elimination of donor-site morbidity, alloplastic biomaterials represent a safe and effective alternative for orbital floor reconstruction; however, the predominance of retrospective, heterogeneous studies in the current evidence base means these findings should inform, rather than replace, individualized surgical decision-making pending further high-quality randomized trials.
1. Congenital angiodysplasias of the extremities are often associated with skeletal disorders, i.e., overgrowth (local giantism, hyperplasia) or reduced growth (hypoplasia). From a clinical point of view three types of combined lesions may be differentiated: (a) a secondary local giantism induced by hemodynamically active congenital a.v. fistulas, usually of intra- and extraosseous location (Weber-type); - (b) local giantism in combination with venous and/or lymphatic angiodysplasias; in this group skeletal overgrowth seems not to be caused by the vascular anomalies but represents more probably a coordinated "inborn error" of tissue composition and distribution (Klippel-Trenaunay-type); - (c) hemangiomatosis usually of venous (cavernous) type, affecting soft tissues as well as bones in association with skeletal hypoplasia. There is a retardation of bone growth by substitution and destruction of the epiphysial cartilages by the intraosseous hemangioma (Servelle-Martorelltype). In most cases (a-c) the use of special angiological investigations allows a clear diagnosis particularly concerning the pathogenesis of skeletal disorders. 2. In looking for an unequivocal terminology the clinical classification of these anomalies should be based on the leading clinical symptome, i.e., the giantism or the angiodysplasia. In this respect the vascular findings take on a predominant position. Paying regard to historical aspects the classification may be completed by the additional term "Klippel-Trenaunay" type, "Weber" type, "Servelle-Martorell" type. 3. An exact angiologic diagnosis gives further informations about prognosis and choice of treatment (group I: Early operative elimination or reduction of the a-v shuntvolume; group II and III: "wait and see!"; usually conservative treatment with compression bandages).
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The authors used a personal technique for the management of infected jaw fractures. If the fracture cleft was not wider than 1 cm, they performed a surgical revision (having made an incision through the mucoperiosteum of the oral vestibule) and replaced the excochleated gra-ulation tissue (including sequestrums) by lyophilized cartilage. The bone fragments were immoblized by bone sutures previously applied and also by additional plastic splints. The substitution of the cartilage by bone begun 6-8 weeks after the surgical intervention (as evidenced by radiographs); the process had terminated in about 6-10 months, the implanted cartilage being completely replaced by newly formed bone. The observation involved 16 cases. The method is also recommended for treatment on an out-patient basis.
The authors report the results of 19 functional investigations carried out for osteochondritis in 11 cases, and osteonecrosis of the knee in 8 cases. The 8 cases of osteonecrosis all had hemodynamic disorders with increased pressure in the bone marrow and stasis due to circulatory obstruction. On the other hand, 5 cases of osteochondritis out of the 11 explored had no disturbance of marrow blood supply. However, of the 6 cases of osteochondritis with vascular disorders, there were 5 who had some other reason which might explain the disorder blood supply within the bone. It thus seems that one may contrast two types of disease: -One, characterized by an intra-osseous circulatory disorder for which one might reserve the terms osteonecrosis, which occurs in patients aged over 60 years, but which may be observed in juvenile forms. - The other, characterised by the absence of any hemodynamic disturbance and in which the foreign body seems to result from a very localised disorder which does not affect the bone marrow blood supply. One may use here the term, osteochondritis. We propose to substitute this physiopathological classification for the classical division based on age and on X-rays. Investigation of the blood supply of the bone, permits, as with strontium, early diagnosis at a pre-radiological stage.
A valuable aeration of the middle ear from the Eustachian tube to the aditus ad antrum is realized by the implantation of a one inch long part of the Vena saphena magna. A tube of polyethylene introduced in the ostium of the Eustachian tube maintains the vein in position during 3-4 weeks, the intima of the vein is an empeachment for synechia with the promontorium. By a special incision the deeper tissues of the ear are formed to a pediculated flap. The splitting of this flap enables the formation of a superficial thin flap, which includes the skin of the external auditory conduct. Applicated on the fascia, a consolidated and fixed neotympanon is realized, the deeper, thicker flap is filling the excavation of the bone. The cartilage of the concha is a valuable substitute of the bridge and the posterior wall of the external auditory conduct.
Urinary adenosine -3' ,5' - cyclic monophosphate was measured in 14 patients with hypercalcaemia not caused by primary hyperparathyroidism. Increased levels were found in patients with malignant disease without bone metastases and believed to be examples of paraendocrine syndrome. Decreased levels were found in patients with metastatic carcinoma involving bone, and in patients with multiple myeloma, lymphoma and immobilisation after fracture. Results obtained during treatment for hypercalaemia are described in three patients. In two hypercalcaemic patients (one with hyperthyroidism and one with breast cancer with bone metastases) normal levels were found. This measurement is a useful substitute for assay of serum parathyroid hormone and is of value in the diagnosis of hypercalcaemia, in monitoring effects of treatment and in revealing underlying mechanisms.
HLA-C*18:06 was identified by a single nucleotide (G>A) substitution at position 275 in HLA-C*18:02.
The HLA-DQB1*06:02:01:41 allele differs from HLA-DQB1*06:02:01:01 by a single nucleotide substitution in intron 2.
In mice, the plaque-forming cell response to sheep red blood cells was stimulated by a mixture of methoxy-substituted glycerol ethers isolated from Greenland shark liver oil and by synthetic 1-0-(2-methoxyhexadecyl)-glycerol, given in the diet. In preliminary experiments, this synthetic compound also increased the ability of parental spleen cells to induce graft-vs.-host reactions in F1 hybrid mice. Glycerol ethers occur in the bone marrow fat of mammals and in the membrane phospholipids. It is postulated that the methoxy-substituted glycerol ethers supplied in the diet may stimulate the bone marrow and/or may be incorporated into membrane lipids, thereby changing the structure and function of the membranes.
In the configuration used, the Hydron sponge did not enhance the ingrowth of bone into the Dacron for prosthesis anchorage. In fact, the presence of the Hydron seemed to retard such ingrowth, even though there was bony incorporation of portions of the Hydron polymer. Fixation was more rigid when Dacron was implanted bare. Hydron sponge does not appear to remain intact within a joint. It would not seem suitable for intra-articular protection of a prosthesis or local delivery of antibiotics here. We did not search further for the polymer in the regional lymph nodes. Hydron sponge is capable of eleciting an unusual phenomenon of woven bone formation. This is "good news" for its potential, but realization of such potential will certainly require additional study. Double and triple interval fluorochrome labelling would be especially helpful in further studying the localization and rate of this bone formation.
Mouse bone collagenase was found to be tightly bound to a heparin-substituted gel at low ionic strength. The bond was reversible, however, and the collagenase could be elutted at high ionic strength. In addition to providing a method for purifying the enzyme with high yield, the results suggest that the strong ionic bond between heparin and collagenase may partially explain the mechanism wherein heparin enhances the activity of mouse bone collagenase.
The HLA-DQB1*03:01:01:75 allele differs from HLA-DQB1*03:01:01:03 by a single nucleotide substitution in intron 2.
OBJECTIVE: The DRB1 locus is strongly associated with both susceptibility and resistance to rheumatoid arthritis (RA). DRB1 alleles encoding the VKA or VRA epitope in positions 11, 71, and 74 confer the highest risk of developing RA, whereas the allele encoding VEA is protective. We therefore investigated the feasibility of creating antigen-specific tolerance without inducing alloreactivity by replacing lysine with glutamic acid at position 71 in DRβ1*04:01. METHODS: Individual DRB1 alleles and the DRB1*04:01K71E allele were cloned into T2 cell lines to measure binding of biotinylated peptides. Transgenic animals expressing DRB1*04:01, DRB1*01:01, or DRB1*04:01K71E were injected with collagen to measure T cell proliferation. Skin and bone marrow transplants between DRB1*04:01K71E and DRB1*04:01 mice were performed to determine if the single amino acid change at position 71 would be recognized as foreign. DRB1*04:01 mice transplanted with DRB1*04:01K71E bone marrow were injected with collagen to test if resistance to collagen sensitization could be transferred. RESULTS: Replacing lysine (K) at position 71 in DRβ1*04:01 with glutamic acid (E) blocked collagen peptide binding and rendered the DRB1*04:01K71E mice resistant to collagen sensitization. Skin and bone marrow transplants from DRB1*04:01K71E mice were not rejected by DRB1*04:01 mice, suggesting the single E71 difference was not recognized as allogeneic. Bone marrow from DRB1*04:01K71E mice adoptively transferred antigen-specific tolerance to collagen to DRB1*04:01 mice. CONCLUSION: These studies demonstrate that editing a single amino acid in DRβ1*04:01 blocks collagen peptide binding without inducing alloreactivity and could therefore represent a gene therapy approach to induce antigen-specific passive tolerance.