USER DEFINED GEOMETRIC FEATURE FOR THE CREATION OF THE FEMORAL NECK ENVELOPING SURFACE

There is a growing demand for application of personalized bone implants (endoprostheses or macro-scaffolds, and fixators) which conform the anatomy of patient. Hence the need for a CAD procedure that enables fast and sufficiently accurate digital reconstruction of the traumatized bone geometry. Research presented in this paper addresses digital reconstruction of the femoral neck fracture. The results point out that User-Defined (geometric) Feature (UDF) concept is the most convenient to use in digital reconstruction of numerous variants of the same topology, such as in this kind of bone region. UDF, named FemoNeck, is developed to demonstrate capability of the chosen concept. Its geometry, controlled by a dozen of parameters, can be easily shaped according to anatomy of femoral neck region of the specific patient. That kind of CAD procedure should use minimally required set of geometric (anatomical) parameters, which can be easily captured from X-ray or Computed Tomography (CT) images. For the statistical analysis of geometry and UDF development we used CT scans of proximal femur of 24 Caucasian female and male adults. The validation of the proposed method was done by applying it for remodeling four femoral necks of four different proximal femurs and by comparing the geometrical congruency between the raw polygonal models gained directly from CT scan and reconstructed models

UNUSUAL ARTERIAL ANASTOMOSES ON THE ANTERIOR SIDE OF THE MEDULLA OBLONGATA: A CASE REPORT

The cerebral arterial circle is a constant carotid-basilar anastomosis on the brain base. However, some transitory primitive intercarotid or carotid-vertebral or carotid-basilar or lateral basilo-vertebral anastomoses can persist and change the common angioarchitecture of the brain. One of these transitory persistent anastomoses was found in a 72-year-old male, autopsied at the Institute for Forensic Medicine of Niš, after  a fatal cranial fracture.  We discovered persistent lateral basilovertebral anastomosis that originated from the right side of the basilar artery, immediately below the beginning of the right anterior inferior cerebellar artery, which was connected with the left anterior spinal artery (ASA). In addition, there were two transversal anastomoses between both vertebral arteries. Although the discovered arterial anastomoses on the ventral side of the medulla oblongata persisted in the human adult, pathologic changes of this artery and other cerebral arteries were not found.  The rarity of these vascular variants in the vertebrobasilar system deserves a description in this article and future scientific attention.Key words: Human brain, lateral basilo-vertebral anastomosis, anterior spinal artery, intervertebral anastomose

Treatment of severe spacticity in multiple sclerosis by continuous intrathecal baclofen

Background. Successful treatment of severe spasticity represents an imperative of symptomatic therapy of multiple sclerosis (MS) due to a significant improvement of physical, psychic and social rehabilitation of MS patients, as well as a longterm cost savings for the additional treatments of conditions arising from uncontrolled severe spasticity. Continuous intrathecal administration of baclofen (ITB), using a subcutaneously implanted programmable infusion pump, is a minimally invasive, reversible method for the treatment of severe diffuse spasticity of the spinal origin. Case report. The first two cases in our country, treated by ITB due to severe spasticity caused by MS, were reported. Despite the local complications of surgical wound healing above the implanted components of the ITB-system in one patient, the optimal reduction of spasticity the with complete elimination of spastic pain was obtained in both patients. Conclusion. Our initial experiences confirmed ITB as a safe and effective therapeutical option for the treatment of intractable spasticity in patients with MS. Major prerequisites for this were adequate patient selection and good control of the basic disease. The use of the minimal invasive implantation technique and the experience in choosing of the adequate ITB-system components, could successfully prevent the occurrence of local complications related to the impaired healing of the ITB-system implantation site

REVERSE ENGINEERING OF THE HUMAN FIBULA BY USING METHOD OF ANATOMICAL FEATURES

This paper describes reverse engineering (RE) of human fibula, on right male bone, using the method of anatomical features (MAF) with the aim to obtain 3D surface model. The first step in the process of reverse engineering was CT scanning and digitalization of data. CT data were obtained with Toshiba MSCT scanner Aquillion 64 and saved in DICOM format. This data were subjected to further processing and imported in Computer Aided Design (CAD) program as STL file. The process continues in CAD program with identification and determination of Referential Geometrical Entities (RGEs) which are crucial for RE process. These RGEs are the basis for definition of axis and planes of intersection. Intersecting polygonal model of fibula bone on upper and lower extremities and the body with these planes gives as result set of curves, which were used for points determination on them. Through these points splines were pulled, and with loft function surface models of extremities and the body of fibula bone is built. Joining and merging of these models leaded to 3D shape model of fibula bone. Accuracy of the model is confirmed by conducting distance and deviation analysis. Model is suitable for rapid prototyping, reconstruction missing parts of fibula bone, orthopedic training and simulation

ANALYSIS OF THE HUMAN CEPHALOMETRIC PARAMETERS IMPORTANT FOR DENTAL PRACTICE

Cephalometry is a measurement of the head by imaging, also taking into account the layer which consists of all the soft tissues of the head. Following the introduction of computed tomography (CT), 3D reconstruction of the head and neck structures and 3D analysis of angular and linear cephalometric parameters was enabled. This study aimed to determine the characteristic cephalometric parameters, using the 2D reconstruction of the multi-slice CT (MSCT) images, which are essential for computer designing of the parametric-geometric-mathematical model (PGMM) of the human skull. We conducted the study on 20 CT scans of adult patients (12 males and 8 females), taken from the radiology archive of the Clinical Center in Niš. Measurements were done on 2D reconstruction images of preselected 3D images of the human head created using MSCT. The values of 29 linear cephalometric parameters (LCP) and 20 angular cephalometric parameters (ACP) were determined. Statistically significant differences between males and females were noted for the distance between the points Sella and Supraorbitale and for the distance between the points Subspinale and Labium superius. Mean values of cephalometric parameters obtained by measurements on 2D CT images can be used to generate normative parameters which represent values used to generate 3D PGMM of the human skull. This PGMM of the skull may allow a more accurate diagnosis, better selection of treatment methods and more accurate prognosis for healing in orthodontics, implantology, oral and maxillofacial surgery

The prevalence of coronary artery anomalies in adults: Studied with computed tomography coronary angiography

Background/Aim. Coronary artery anomalies are an uncommon but important cause of chest pain, and in some cases of hemodynamically significant abnormalities, sudden cardiac death. The aim of the research was to establish the prevalence of the coronary arteries anomalies in our population. Methods. The study group included 1,562 patients (810 men, 752 women, average age 64.3 ± 12.0 years; range 32–80 years) who were scheduled for 64-slice computed tomography (MSCT), which enables detailed visualization of coronary arteries and heart anatomy. All examinations were made due to suspicion (atypical chest pain, angina equivalent symptoms or multiple risk factors for cardiovascular disease) or assumption of progression of coronary artery disease. Results. From January 2010 till December 2014 a total number of 1,562 patients were sent for evaluation of coronary arteries. The coronary anomalies were found in 45 (2.88%) patients. The most frequent coronary anomaly seen in our population group was absence of left main trunk with the separate origin of the left anterior descending artery (LAD) and left circumflex artery (LCx) originating from a left coronary sinus (LCS). This was found in 12 patients (an incidence of 0.77% or 26.7% of all coronary anomalies). Anomalous location of coronary ostium outside normal aortic sinuses in our study was present as right coronary artery (RCA) that arises from left anterior sinus in 5 (0.32%) patients and left coronary artery from non-coronary sinus in two (0.13%) patients. Conclusion. Knowledge of anomalies of the coronary arteries and their recognition on the multislice computed tomography is of great importance for the further planning of a possible therapeutic treatment. Coronary anomalies that are considered insignificant will require no further therapeutic treatment. But the detection of malignant coronary anomalies will certainly save many lives

The prevalence of coronary artery anomalies in adults: Studied with computed tomography coronary angiography

Background/Aim. Coronary artery anomalies are an uncommon but important cause of chest pain, and in some cases of hemodynamically significant abnormalities, sudden cardiac death. The aim of the research was to establish the prevalence of the coronary arteries anomalies in our population. Methods. The study group included 1,562 patients (810 men, 752 women, average age 64.3 ± 12.0 years; range 32–80 years) who were scheduled for 64-slice computed tomography (MSCT), which enables detailed visualization of coronary arteries and heart anatomy. All examinations were made due to suspicion (atypical chest pain, angina equivalent symptoms or multiple risk factors for cardiovascular disease) or assumption of progression of coronary artery disease. Results. From January 2010 till December 2014 a total number of 1,562 patients were sent for evaluation of coronary arteries. The coronary anomalies were found in 45 (2.88%) patients. The most frequent coronary anomaly seen in our population group was absence of left main trunk with the separate origin of the left anterior descending artery (LAD) and left circumflex artery (LCx) originating from a left coronary sinus (LCS). This was found in 12 patients (an incidence of 0.77% or 26.7% of all coronary anomalies). Anomalous location of coronary ostium outside normal aortic sinuses in our study was present as right coronary artery (RCA) that arises from left anterior sinus in 5 (0.32%) patients and left coronary artery from non-coronary sinus in two (0.13%) patients. Conclusion. Knowledge of anomalies of the coronary arteries and their recognition on the multislice computed tomography is of great importance for the further planning of a possible therapeutic treatment. Coronary anomalies that are considered insignificant will require no further therapeutic treatment. But the detection of malignant coronary anomalies will certainly save many lives

Comparative analysis of linear morphometric parameters of the humane mandibula obtained by direct and indirect measurement

Background/Aim. Reconstruction of lost, damaged or distorted mandibular bone presents a challenge from the functional side, as well as from the esthetic point of view. The aim of this study was to determinate potential differences between values of the basic linear moprhometric parameters (LMPs) obtained by direct and indirect manual measurement of the same humane mandibles, with accuracy testing of indirect measurement, which are routinely used in every-day clinical practice. The results are essential for defining of parametric model of the 'standard mandible' and virtual modeling of the humane mandible in future researches as well as in clinical medicine. Methods. A total number of 12 dry bony mandibles of human adults were studied. According to the standard anatomical landmarks, 10 standard LPMs were measured on each mandible by different manual methods: directly by a sliding caliper with nonius, and indirectly using standard software on two-dimensional (2D) reconstructions of mandibular multislice computed tomography (MSCT) scans. The values obtained by the different measuring methods were matched for the same LMPs. Results. Statistically significant differences between compared LMPs values obtained by different measuring methods, appeared in the gnathio-interdental distance (Gn-IdD), as well as in the gnathio-condylar distance (Gn-CoD), bilaterally. In both parameters, significantly higher mean values (with percent of difference) were obtained by direct versus indirect measurement: Gn-IdD (21.57%; 29.2 mm vs 22.9 mm; p = 0.004); Gn-CoD left side (14.1%; 122.7 mm vs 105.4 cm; p = 0.001); Gn-CoD right side (11.87%; 124.7 mm vs 109.9 mm; p = 0.009). Conclusion. According to the observed inaccuracy of indirect measurement, we recommended the use of a correction factor for calculation of both Gn-IdD and Gn-CoD real vales, in defining of parametric model of the 'standard mandible' based on indirect morphometry on 2D reconstructions of mandibular MSCT scans. Additional studies with larger number of specimens and quantification of anatomical variations regarding to sex, age, dentition status and ethnic origin, additionally should increase measurement accuracy and consequently reliability of future parametric model of the human mandible

The Parametric Model of the Human Mandible Coronoid Process Created by Method of Anatomical Features

Geometrically accurate and anatomically correct 3D models of the human bones are of great importance for medical research and practice in orthopedics and surgery. These geometrical models can be created by the use of techniques which can be based on input geometrical data acquired from volumetric methods of scanning (e.g., Computed Tomography (CT)) or on the 2D images (e.g., X-ray). Geometrical models of human bones created in such way can be applied for education of medical practitioners, preoperative planning, etc. In cases when geometrical data about the human bone is incomplete (e.g., fractures), it may be necessary to create its complete geometrical model. The possible solution for this problem is the application of parametric models. The geometry of these models can be changed and adapted to the specific patient based on the values of parameters acquired from medical images (e.g., X-ray). In this paper, Method of Anatomical Features (MAF) which enables creation of geometrically precise and anatomically accurate geometrical models of the human bones is implemented for the creation of the parametric model of the Human Mandible Coronoid Process (HMCP). The obtained results about geometrical accuracy of the model are quite satisfactory, as it is stated by the medical practitioners and confirmed in the literature

Surgical treatment of tibial nonunion after wounding by high velocity missile and external fixators: A case report

Introduction. The missiles of modern firearms can cause severe fractures of the extremity. High velocity missile fractures of the tibia are characterized by massive tissue destruction and primary contamination with polymorphic bacteria. Treatment of these fractures is often complicated by delayed healing, poor position healing, nonhealing and bone tissue infection. Case Outline. We present the management of tibial nonunion after wounding by high velocity missile and primary treatment by external fixation in a 25-year-old patient. The patient was primarily treated with external fixation and reconstructive operations of the soft tissue without union of the fracture. Seven months after injury we placed a compression-distraction external fixator type Mitkovic and started with compression and distraction in the fracture focus after osteotomy of the fibula and autospongioplasty. We recorded satisfactory fracture healing and good functional outcome. Conclusion. Contamination and devitalization of the softtissue envelope increase the risk of infection and nonunion in fractures after wounding by high velocity missile. The use of the compression-distraction external fixator type Mitkovic may be an effective method in nonunions of the tibia after this kind of injury. [Projekat Ministarstva nauke Republike Srbije, br. III 41004