High Precision Bone Cutting by Er: YAG Lasers Might Minimize the Invasiveness of Navigated Brain Biopsies

Biopsies of brain tissue are sampled and examined to establish a diagnosis and to plan further treatment, e.g. for brain tumors. The neurosurgical procedure of sampling brain tissue for histologic examination is still a relatively invasive procedure that carries several disadvantages. The “proof of concept”-objective of this study is to answer the question if laser technology might be a potential tool to make brain biopsies less invasive, faster and safer. Laser technology might carry the opportunity to miniaturize the necessary burr hole and also to angulate the burr hole much more tangential in relation to the bone surface in order to take biopsies from brain regions that are usually only difficult and hazardous to access. We examined if it is possible to miniaturize the hole in the skull bone to such a high extent that potentially the laser-created canal itself may guide the biopsy needle with sufficient accuracy. The 2-dimensional, i.e. radial tolerance of the tip of biopsy needles inserted in these canals was measured under defined lateral loads which mimic mechanical forces applied by a surgeon. The canals through the skull bones were planned in angles of 90° (perpendicular) and 45° relative to the bone surface. We created a total of 33 holes with an Er : YAG laser in human skull bones. We could demonstrate that the achievable radial tolerance concerning the guidance of a biopsy needle by a laser created bone canal is within the range of the actual accuracy of a usual navigated device if the canal is at least 4 mm in length. Lateral mechanical loads applied to the biopsy needle had only minor impact on the measurable radial tolerance. Furthermore, in contrast to mechanical drilling systems, laser technology enables the creation of bone canals in pointed angles to the skull bone surface. The latter opens the perspective to sample biopsies in brain areas that are usually not or only hazardous to access.

In-utero Diagnosis of Double Encephalocele - Imaging Features and Review of Literature

Encephalocele is protrusion of brain parenchyma through a defect in the cranium. It is classified into various types based on the defect location: sincipital (fronto-ethmoidal), basal (trans-sphenoidal, spheno-ethmoidal, trans-ethmoidal, and spheno-orbital), occipital and parietal. Double encephaloceles are very rare with only a handful of cases reported in the literature and most of these cases involved either occipital or sub-occipital region. All, except one, cases of double encephaloceles were diagnosed postnatally. We present a case of double encephalocele with parietal and occipital components diagnosed in utero. To the best of our knowledge, this is the first case of double encephalocele involving the parietal and occipital skull bones diagnosed in-utero.

Features of the formation of certain bones of the skull at the early stages of human ontogenesis

The study of morphogenesis and embryotopography of skull bones is important not only in understanding the normal development of the human embryo but also will improve existing methods of invasive treatment and visualization of various pathologies of the central nervous system in children.The aim was to investigate the peculiarities of morphogenesis and topography of some skull bones during the early stages of human ontogenesis.Material and methods. We have studied 14 series of consecutive histological sections of human embryos and pre-fetuses aged 6 to 11 weeks of intrauterine development by using a set of topical morphological methods (anthropometry, morphometry, histology, three-dimensional reconstruction).Results. The frontal and parietal bones appear at the end of the embryonic period as mesenchymal rudiments that gradually expand upwards from primary points of ossification (starting from the basolateral parts of the head). During 8th week of IUD, the germ of the ectomeningeal capsule is detected in the form of a thin plate, close to the brain. At the beginning of the pre-fetal period, histological signs of membranous ossification are revealed; frontal and parietal bones develop from paired rudiments, which gradually fuse, which was accompanied by active angiogenesis.Conclusions. The primary ossification centers in frontal and parietal bones of the human embryo appear at the beginning of embryological period and develop by membranous type. Two ossification centers appear in frontal and parietal bones and they gradually merge. At the beginning of the prenatal period, the rudiment of a small wing of the sphenoid, spheno-ethmoidal cartilage and signs of merging of both ossification centers in the parietal bone are detected.

NEXAFS study of carbonate substituted bioapatite

The investigation of unique carbonate substituted bioapatite of Champsocephalus gunnari icefish jaw and skull bones was carried out using NEXAFS spectroscopy. It has been established that these bones contain the B-type carbonate substituted hydroxyapatit with a content [CO3]2- anion of about 0.79-3.07 wt.%.

Philichthys xiphiae (Copepoda; Philichthyidae) – an interesting cranium parasite of the swordfish Xiphias gladius collected from the Baltic Sea

The swordfish, Xiphias gladius Linnaeus, 1758, is a fish that sporadically enters the Baltic Sea. The present paper describes the identification of a very rarely recorded and poorly studied copepod of the family Philichthyidae – Philichthys xiphiae Steenstrup, 1862 – in a dead swordfish found on a sea beach in Dźwirzyno (Poland) in 2016. Philichthyidae are parasites inhabiting the sensory canals in the lateral line and skull bones of marine fish. In the present case, two P. xiphiae females were found, which constitutes the first record of the species in the Baltic area.

​Morphometrical Studies on Skull Bones of Adult Blue Bull (Boselaphus tragocamelus)

Background: The Blue bull (Boselaphus tragocamelus) is regarded as one of the biggest antelopes in Asia and safeguarded beneath the IUCN since 2003 and under safeguard of ‘Schedule III’ of the Indian Wildlife Protection Act, 1972. This study focused on the detailed gross morphometrical study of mid thoracic ribs of Blue Bull (Boselaphus tragocamelus). Methods: The present study was carried out on the skull of six specimens of adult Blue bull (Boselaphus tragocamelus) of either sex. The measurements of various parameters of skull bones were taken with the help of weighing machine, thread, scale and digital Vernier’s calliper. Result: The average length of skull was found to be 40.9±1.08 cm in female, which was significantly less (P less than 0.05) than that of males, where it was recorded as 49.5±097 cm. Similarly, the average facial length was found to be 16.6±0.20 cm in female, which was significantly less (P less than 0.05) than that of males, where it was recorded as 22.0±0.17 cm. The average left cranio-caudal length of tympanic bulla was found to be 4.1±0.15 cm in female, which was significantly less (P less than 0.05) than that of males, where it was recorded as 4.5±0.19 cm. The average length of left zygomatic process of squamous temporal bone was found to be 5.7±0.11 cm in female, which was significantly less (P less than 0.05) than that of males, where it was recorded as 7.1±0.08 cm. The average distance between the last incisor and first premolar teeth was found to be 6.3±0.12 cm in female, which was significantly less (P less than 0.05) than that of males, where it was recorded as 8.2±0.17 cm.

Minimalistic reconstruction of exposed skull in a complex craniovertebral polytrauma

Background: In stable craniovertebral injuries complicated by polytrauma, rigorous spinal immobilization is essential for neuroprotection. Scalp and forehead reconstruction in these circumstances are safest when performed under local anesthesia, maintaining cervical immobilization. Case Description: A sizeable 10 × 6.5 cm forehead defect was reconstructed utilizing regenerative principles under local anesthesia and sedation in a 54-year-old woman. After adequate debridement of gangrenous soft tissues, exposed outer skull bones were trephined, forehead defect covered with a synthetic biomaterial, and the patient was discharged thereafter. Granulating neodermis regenerated within the biomaterial over the next 6 weeks. Weekly platelet-rich plasma injections along the wound margins facilitated wound regeneration. Dimensions reduced by two-thirds to 6.5 × 3.5 cm with wound regeneration and contraction, while granulating neodermis covered the remaining skull-bones. Split skin-grafting over the neodermis ensured satisfying long-term results, with similar color, texture, soft-tissue thickness, and sensation. Multiple occipitocervical, spinal, scapular, and rib fractures healed well with strict immobilization. Conclusion: Good long-term results were achieved with significantly reduced dangers, complications, hospitalization, and costs than traditional reconstructive flap surgeries. Minimalistic reconstruction utilizing tissue engineering and regenerative medicine principles appears beneficial for patients with grave spinal injuries.

Knife and Belt: Analysis of Seima-Turbino Bronze Weapons

A bronze knife from the burial site near Rostovka village was found in a grave under the skull bones that belonged to a nine–ten-year-old child. Sopka-2/4B Krotovo necropolis has two burials, in which daggers were found under the bones of a child and a man. This ritual might have been associated with the belief that wearing a knife around one’s neck behind one’s back could make the owner invulnerable. Necklaces and belts are known to have a similar magic function. The SeimaTurbino tradition of belt weapons still remains understudied: in fact, no belt weapon has been described for this culture so far, as the belts might have been made of wool. Various weaving techniques are based on the materials of the Sinthashta and Petrovka sites. The newly-discovered images on the Seima-Turbino knives add new information to the known ceremonial practice.

Applications of the Poly(methyl methacrilate) (PMMA) in Cranioplasty

Cranioplasty is a surgical procedure that is used to correct any defect in skull bones after a previous decompresive craniectomy, usually made for traumatic brain injuries, with ischemic or hemorragic nature, or after a tumor removal. A composite for modeling on a defect in skull bones was prepared by crosslinking poly(methyl methacrylate) in the presence of barium sulfate. The crosslinking rate of methyl polymethacrylate in the presence of the benzoyl peroxide initiator, the N, N-dimethyl-β-toluidine polymerization accelerator and the hydroquinone polymerization inhibitor allows modeling according to the location and size of the defect. Thus, the concentration of composite precursor components was optimal for this purpose. The TGA diagram shows the almost total consumption of methyl methacrylate and butyl methacrylate monomers in the crosslinking process of methyl polymethacrylate with the formation of the composite. This technical study demonstrate the efficacy of this treatment, as well as to show all the possible scenarios in such procedures.