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PubMed1994

Anatomic study of the orbital septum (22.10.93).

The orbital septum separates the intraorbital fat from the palpebral part of the orbicularis oculi m. An anatomic study after injection of colorant into the intraorbital fat allows definition of a fibroadipose layer anterior to the orbital septum. This consists of radial fibers and extraorbital fatty lobules. The septum is derived embryologically from the mesenchyme of the second arch, but the structure of the anterior layer remains controversial. The septum has an important mechanical function in containing the orbital fat and is involved in orbital movements. A knowledge of these different layers facilitates surgical approaches and helps to define the anatomic landmarks in palpebral surgery for conditions such as ptosis and in blepharoplasty.

Anthropometry↗
PubMed1985

Anatomical basis for study of acetabular migration of the prosthetic cup used in arthroplasty of the hip: a new technique for measurement of migration.

A retrospective study was carried out on 96 partial hip prostheses. Results of this study led us to define new radiological criteria for evaluation of the anatomical position of the prosthetic cup in the acetabulum. A method of measurement of the migration of the prosthetic cup in the acetabulum is proposed based on the results of roentgenological and anatomical study. The anatomical landmarks, geometric constructions and methods of computation of such measurement are described. The application of this technique to radiological/anatomical study was found to be reliable and allowed the determination of prognostic factors indicative of poor acetabular tolerance of the prosthetic cup.

Acetabulum↗
PubMed1995

Confirmation of cecal intubation during colonoscopy.

PURPOSE: Establishing intubation of the cecum can be a laborious, frustrating, and sometimes erroneous endeavor. Following confirmed colonoscopic intubation of the cecum, the presence of three anatomic landmarks (alone and in combination) were evaluated to precisely define their reliability. METHODS: Between February 1991 and January 1992, 771 of 904 consecutive colonoscopic examinations were completed to the cecum as confirmed by fluoroscopy. RESULTS: All three cecal landmarks studied (ileocecal valve, appendiceal orifice, and transillumination) were present in 64 percent of patients, and two landmarks were seen in 32 percent (96 percent of patients had multiple landmarks). The ileocecal valve was the most reliable cecal landmark (98 percent), followed by the appendiceal orifice (87 percent) and transillumination through the abdominal wall (75 percent). CONCLUSIONS: The ileocecal valve is the most reliable cecal landmark and is invariably visualized, even when all other cecal landmarks are obscure. Although other cecal landmarks are usually identifiable, they are most valuable when found in association with the ileocecal valve.

Abdominal Muscles↗
PubMed1988

Correlation between anatomy and computed tomography in the occipito-temporal plane: application to cerebral lobectomy.

Identification of the anatomic limits of cerebral lobectomies has for long been based on the indirect data provided by ventriculography, arteriography and the statistical anatomic details of the stereotactic atlases. Today, it is simple to identify the cerebral anatomic structures directly on scanner sections, to assess the limits of a required lobectomy and to monitor the outcome. This appears to be just as valid in clinical conditions where the anatomic structures remain near-normal (surgery of epilepsy) as in those where they may be deformed (such as the surgery of malignant gliomata). In order to establish precise correlations between the anatomy and the computed tomographic findings, a study in the occipito-temporal plane used regularly in CT was carried out in 18 brains. Frontal, temporal and occipital lobectomies were performed on these brains using the anatomic landmarks commonly accepted in neurosurgery. The practical import of these theoretic lobectomies studied in the OT plane is illustrated by some examples of surgical excision of lobar cerebral lesions.

Brain↗
PubMed1991

Comparison of technetium 99m polyclonal human immunoglobulin and technetium 99m monoclonal antibodies for imaging chronic osteomyelitis. First clinical results.

The accuracy of technetium-99m human immunoglobulin (HIG) for the detection of chronic osteomyelitis (OM) was compared with white blood cell scintigraphy using 99mTc-labelled monoclonal mouse antibodies (MAB). Seventeen patients suspected of having OM in 20 lesions went through three-phase skeletal scintigraphy, HIG scintigraphy and MAB scintigraphy. The final diagnosis was established by open surgery, histology and bacteriology. Chronic OM was proved in 14/20 lesions. Six of these 14 infections were located in peripheral areas without active bone marrow and 8/14 in central areas with active bone marrow. In peripheral OM, 5/6 with HIG and 6/6 with MAB were true positives. In the central skeleton all 8/8 infections appeared as cold lesions in the MAB study, which were defined as being false negative due to their non-specificity. Using HIG, 5/8 central infections were determined to be truly positive by showing photon-rich lesions. These 5 lesions were located in the hip region and in the pelvis, whereas 3 lesions of the spine were missed. There were no false-positive results in either studies. In conclusion, MAB was superior to HIG in peripheral OM concerning sensitivity, anatomical landmarks and differentiation of soft tissue versus bone infection. In central OM MAB detected all lesions accurately, but no differential diagnosis was possible due to the non-specificity of photon-low areas. In this respect HIG seems to be more specific due to the increased accumulation even in central infection sites.

Adult↗
PubMed2000

3D reconstruction method from biplanar radiography using non-stereocorresponding points and elastic deformable meshes.

Standard 3D reconstruction of bones using stereoradiography is limited by the number of anatomical landmarks visible in more than one projection. The proposed technique enables the 3D reconstruction of additional landmarks that can be identified in only one of the radiographs. The principle of this method is the deformation of an elastic object that respects stereocorresponding and non-stereocorresponding observations available in different projections. This technique is based on the principle that any non-stereocorresponding point belongs to a line joining the X-ray source and the projection of the point in one view. The aim is to determine the 3D position of these points on their line of projection when submitted to geometrical and topological constraints. This technique is used to obtain the 3D geometry of 18 cadaveric upper cervical vertebrae. The reconstructed geometry obtained is compared with direct measurements using a magnetic digitiser. The order of precision determined with the point-to-surface distance between the reconstruction obtained with that technique and reference measurements is about 1 mm, depending on the vertebrae studied. Comparison results indicate that the obtained reconstruction is close to the actual vertebral geometry. This method can therefore be proposed to obtain the 3D geometry of vertebrae.

Cervical Vertebrae↗
PubMed1986

High resolution ultrasonography of the parotid gland in children.

High resolution ultrasonography has revolutionized imaging of the superficial parotid gland. The fine morphology of the parotid gland can be exquisitely visulized. Anatomical landmarks such as the mastoid tip, the sternocleidomastoid muscle, the styloid process, the posterior facial vein, the internal jugular vein, and the external carotid artery can easily be identified in relationship to the parotid. The course of the facial nerve can be inferred by visualization of these landmarks. Common masses within the parotid in children such as hemangiomas, mixed parotid tumors, and lymphadenopathy can be demonstrated. Parotid masses are uncommon in children but can be easily evaluated by high resolution ultrasonography.

Adenoma, Pleomorphic↗
PubMed1988

High resolution ultrasonography of the parotid gland in children. Part II.

The authors previously have reported a technique for visualizing the parotid gland with high resolution ultrasonography. The fine morphology of the parotid gland as well as normal anatomical landmarks were well visualized with ultrasonography. This study has continued for the past two years, and an additional twenty patients with suspected parotid pathology are presented. Ultrasound was helpful in (1) making a specific diagnosis in sialectasis, (2) determining whether parotid swelling was secondary to enlargement of adjacent tissues or indeed secondary to an intraparotid mass, (3) demonstrating whether enlargement of adjacent tissues was vascular by using duplex Doppler scanning, and (4) follow-up of enlarged nodes within the parotid and adjacent to the parotid for development of abscess formation.

Adolescent↗
PubMed1998

Estimation of 3D location and orientation of human vertebral facet joints from standing digital radiographs.

This study provides a biplanar radiographic reconstruction method of volumes of interest to evaluate the location, dimensions and orientation of human facet joints. Visibility of facet anatomical landmarks and areas of interest was evaluated on digital radiographs of 20 idiopathic scoliotic adolescents. Areas of interest have provided the most reliable evaluation of facet joints on postero-anterior and lateral digital radiographs. Volumes of interest of a thoracic and lumbar spinal segment (T1 to L3) were computed using the proposed biplanar 3D reconstruction method and compared with serial tomographic reconstructed models. Differences of 1.5 +/- 0.7 mm in 3D location and 1.8 +/- 1.2 degrees in sagittal orientation of volumes of interest were observed between both representations. This in vivo geometric information on human vertebral facet joints will help us to understand their role in spinal disorders and will provide important data for personalised biomechanical simulations.

Adolescent↗
PubMed2001

Patient position reproducibility in fractionated stereotactically guided conformal radiotherapy using the BrainLab mask system.

PURPOSE: Dedicated mask systems nowadays allow the use of stereotactic radiotherapy in fractionated regimes, therefore combining the advantages of high precision radiotherapy with the biological benefit of fractionation. Therefore the knowledge of institution specific isocenter accuracy is essential for decision-making about margins to be allowed to form the planning target volume. PATIENTS AND METHOD: Measurements of isocenter deviations during fractionated treatments were performed in 33 patients using the simulator Simulix-xy (Oldelft) in connection with the BrainLab angiographic localizer-box as well as port-films. In both cases repeated images were overlaid by use of anatomical landmarks with a methodical accuracy in the order of 0.5 mm. RESULTS: Both methods yield random isocenter deviations of less then 2 mm (standard deviation) in all three directions and no significant systematic deviations. These values are in the order of the accuracy of the method, obtained by comparison of two independent investigators, as well as they are comparable with the literature. CONCLUSIONS: The accuracy of less than 2 mm indicates safety margins of 3-4 mm as sufficient for clinical routine to cover the target in 95.5% of all set-ups (2 SD).

Brain Neoplasms↗
PubMed2002

CT-based study on potential mediastinal lymph node spread of patients with lung cancer. Contribution to 3-D treatment planning for adjuvant radiotherapy of the mediastinum.

AIMS: To provide a schematized and graduated CT reference series of the mediastinum showing CT-detectable lymph node areas of lung cancer patients to support 3-D treatment planning and documentation for adjuvant irradiation of the mediastinum. PATIENTS AND METHODS: Cross sections of mediastinal structures from one male individual were schematized and overlaid with a 1 cm2 reference grid. Mediastinal CT scans of 100 consecutive patients with histologically proven lung cancer and CT-detectable lymph nodes were evaluated. For each patient the outlines of all identifiable nodes were transferred into the schematized CT series according to their localization in relation to anatomical landmarks. The outlines were centered in a predefined way into relevant squares of the reference grid. The number of patients with nodes projecting to individual CT cross sections was determined. Further, the number and percentage of patients locating to positive grid squares were analyzed. RESULTS: A differentiated pattern of CT-detectable lymph nodes was confirmed. Along the longitudinal axis the CT-detectable nodes followed a Gaussian distribution with its maximum (89% of all patients) at the level of the tracheal bifurcation. At different transverse levels closely circumscribed central areas with node positive grid squares were identified harboring up to 72% of the patients (locating to the front of the trachea, the bifurcation and below the carina). Peripheral areas showed only sporadically node positive grid squares, usually representing less than 5% of the patients. CONCLUSIONS: These schematized and graduated CT cross sections show areas of CT-detectable lymph node spread from the view of 3-D planning. They are of additional help to individualize mediastinal target volumes and/or dose distributions, particularly when administering adjuvant irradiation to patients without mediastinal lymph node involvement. Classifying mediastinal structures by using a grid square easily allows to describe and document target volumes and dose distributions per cross section.

Adult↗
PubMed2002

Simulator verification of the accuracy of patient repositioning after virtual simulation. Is physical simulation still needed?

PURPOSE: To evaluate the frequency and amount of displacements after repositioning a patient on the physical simulator following virtual simulation. MATERIAL AND METHODS: After laser marking at the CT scanner and virtual simulation, patients were repositioned on the simulator. The isocenter obtained from the calculated table movements was checked by fluoroscopically measuring the distances to standardized anatomic landmarks and comparing them to the treatment plan. RESULTS: In 86% of patients, displacements were < or = 0.5 cm. There was no significant difference between the supine and prone position, diagnosis categories or CT reconstruction indices. The use of immobilization devices and cranial versus body stem localization did make a significant difference. Rates of exact repositioning were high in brain and head and neck patients and comparatively low in abdominal tumors and breast cancer. CONCLUSIONS: Immobilization devices play an important role for the precision of radiotherapy. Whenever precise positioning is possible (e. g. with a head mask), virtual simulation alone might be sufficient. Patients with abdominal and breast tumors, were repositioning precision is often suboptimal, might profit from an additional physical simulation.

Adult↗
PubMed2003

[Improved patient repositioning accuracy by integrating an additional jaw fixation into a high precision face mask system in stereotactic radiotherapy of the head].

BACKGROUND: For high precision radiotherapy of the neurocranium a precise, reproducible positioning technique is the basic prerequisite. The aim of this study was to assess the influence of a modification of the commercially available stereotactical BrainLab-head mask system on accuracy in patient positioning during fractionated radiotherapy. MATERIAL AND METHODS: 29 patients were treated with stereotactic radiotherapy of the head. Immobilization was provided by a two layer thermoplastic mask system (BrainLab). 18 of these patients received an additional custom made fixation either of the upper jaw (OKF) or of the mandibula (UKF). The positioning accuracy was assessed by measurements of the shifting of anatomical landmarks in relation to the rigid mask system on biplanar simulator films using a digital imaging system. Before each measurement a fine adjustment of the simulator to an optical ring system was performed. The reference radiographs were done just before CT-planning. During a 2-7 weeks lasting course of radiotherapy displacement measurements in relation to the reference images for all three dimensions (z, y and x) were done once a week. In 29 patients 844 measurements were analyzed. RESULTS: An additional jaw fixation improves the reproducibility of patient positioning significantly in all three spatial dimensions. The standard deviation in lateral direction (x) was 0.6 mm with jaw fixation vs. 0.7 mm without jaw fixation (p < 0.001); in longitudinal direction (z) (measured in 0 degree radiographs) 0.5 mm vs. 1.3 mm (p < 0.001); in longitudinal direction (measured in 90 degrees radiographs) 0.5 mm vs. 1.5 mm (p < 0.001); in vertical direction (y) 0.6 mm vs. 0.9 mm (p = 0.001). No significant differences in standard deviations were found comparing OKF (n = 14) with UKF (n = 4). CONCLUSION: A significant improvement in reposition accuracy using an additional, individually formed jaw fixation can be acquired. The variability of positioning can be reduced especially in the z-direction. A further reduction of the safety margin around the target volume--especially in benign tumors--is possible by improved fixation technique.

Brain Neoplasms↗
PubMed1994

[Ultrasonic guided cannulation of the axillary vein in intensive care patients].

Cannulation of the axillary vein is claimed to be an effective and relatively safe access to the central venous (CV) system [2, 4, 5, 8]. However, anatomical landmarks recommended for venous location (Muskulus pectoralis minor, processus coracoideus) are probably hard to identify in the majority of intensive care (ICU) patients. This investigation evaluated unidirectional 8 MHz Doppler ultrasound (US) in locating the axillary vein. Success rates and complications of this CV access in ICU patients is analysed. METHODS. The experimental design was approved by the local ethical committee (RUB). In 50 patients from our ICU cannulation of the axillary vein was attempted; all were in need of a CV line. Other CV puncture sites (except for the subclavian vein) were associated with contraindications. Patients were placed in a 15 degrees Trendelenburg position (15 exceptions); the arm was abducted to 45 degrees [5, 8]. The course of the axillary vein was located by Doppler US and marked on the skin with a felt pen. Prior to puncture, US intensity was judged by a score ranging from 0 to 4. After skin desinfection, sterile draping, and local anaesthesia, puncture of the axillary vein was attempted. The puncture kit LeaderCath 11,515 (Vygon, Aachen, FRG) was used. When venous blood could be aspirated, the Seldinger guidewire was inserted and the definite catheter placed. The experimental design allowed up to ten punctures, slightly modified in angle and direction of the needle, if puncture of the axillary vein or guide-wire placement failed. The cannulation attempt was classified as unsuccessful in the following cases: malposition, axillary vein not encountered by the puncture needle, guide-wire placement unsuccessful, or if identification and cannulation of the vein lasted more than 20 min. The puncture attempts were evaluated in respect to success rate, time, relation of US intensity to puncture attempts and CV pressure, complications, and malposition. RESULTS. Of the 50 attempted CV catheters, 43 were placed successfully. In 2 cases the axillary vein could not be encountered by the puncture needle. Guide-wire placement did not succeed in 4 patients. One catheter was malpositioned in the ipsilateral internal jugular vein. Four inadvertent punctures of the axillary artery remained without sequelae after compression. No further puncture-related complications were observed. With high US intensity score the number of puncture attempts necessary for successful vein cannulation was lower. On the other hand, complications and puncture failure seemed to be more frequent in patients with lower US intensity scores. DISCUSSION. CV access via the axillary vein had a satisfying success rate (43/50) and proved to be a safe procedure in our ICU patients despite higher risk factors compared to a healthy population. Although ethical reasons did not allow a randomised comparison with the standard technique, location of the axillary vein by Doppler US is likely to improve cannulation results and reduce complications induced by "blind" needle probing. With a low US intensity score, the rate of successful punctures is lower and complication rates increase. In some patients, e.g., those with extended tumour operations involving the head and neck, CV access via the axillary vein may be of high clinical value.

Axillary Vein↗
PubMed2000

[A new technique for laparoscopic placement of the adjustable gastric band (LAP-band) for preventing slippage].

BACKGROUND: Slippage (SP) of the stomach is the most common postoperative complication after laparoscopic adjustable silicone gastric banding (LAS-GB) for morbid obesity. METHODS AND PATIENTS: A randomized prospective study was constructed in order to determine whether laparoscopic placement behind the cardia (RKP) is associated with a lower incidence of postoperative SP and pouch dilation than after a retrogastric placement (RGP) of the LAP band using a common technique. Morbidly obese patients presenting for LASGB were randomized to undergo either an RKP (n = 50) or an RGP (n = 51). RESULTS: There were three postoperative SP and three pouch dilations in the RGP group versus no postoperative complication in the RKP group. CONCLUSIONS: The placement of LAP band by the RKP technique is safe and followed by a lower frequency of postoperative complications than with the RGP technique. Clear anatomical landmarks are a benefit to the education and learning curve of LASGB.

Adolescent↗
PubMed2006

[The use of the BrainLAB Kolibri navigation system in endoscopic paranasal sinus surgery under local anaesthesia. An analysis of 35 cases].

BACKGROUND: As a result of technological advances, 3D-navigation systems are playing an increasingly important role in paranasal sinus and anterior skull base surgery. PATIENTS AND METHODS: The BrainLAB Kolibri navigation system (BrainLAB, Heimstetten, Germany) was used in the surgical management of chronic sinusitis and nasal polyposis in 35 patients. Surgery was performed under local anaesthesia. In order to compare this technique with traditional methods, 35 additional patients underwent conventional surgery. A clinical plausibility test using specific anatomical landmarks was performed to evaluate intraoperative navigation accuracy. In addition, a standardised questionnaire was used to document setup and registration times. Standardised rating scales helped assess whether the system can make surgery safer. RESULTS: It took approximately 5.8 min to set up the navigation system. The time required for system and patient positioning, including the attachment of the headband, was 4.2 min on average. Patient registration with the z-touch system was completed after an average of 4.2 min. It took an average of approximately 8.1 min to register a patient using the soft-touch system. The use of the navigation system increased the total time for preparation and surgery by approximately 50% in comparison to the conventional technique. An average accuracy of 1.5-2.3 mm in all three planes was measured. Participating surgeons felt that the system made surgery considerably safer. CONCLUSIONS: The BrainLAB Kolibri navigation system offers good accuracy, a short setup time and an easy registration technique. The combination of these qualities and intuitive operation make this system a suitable option for routine use in paranasal sinus surgery. As a result of its compactness, the BrainLAB Kolibri navigation system can be moved easily between different operating rooms and can also be used in small facilities (e.g. container operating theatres in field hospitals).

Adult↗
PubMed2002

[Endoscopically controlled stabilization of humerus shaft fractures. The endoscope as an aid in minimally invasive osteosynthesis].

This study describes the anatomical basis of direct visualization of the radial nerve and of fracture reduction in humeral shaft nailing and reports first clinical results. Fourteen cadavers were random selected and dissected in order to determine the exact course of the radial nerve in relationship to anatomical landmarks. In individuals with a total humeral length between 25-33 cm the radial nerve was found to cross the humeral shaft exactly in the middle of the long axis of the humeral shaft. The average distance from the lateral epicondyle to the point were the radial nerve penetrates the lateral intermuscular septum was 11.9 +/- 1.0 cm, the distance from the posterior tip of the acromion to the crossing of the nerve with the medial border of the humeral shaft was 12.9 +/- 1.5 cm. Using these landmarks in six clinical cases fracture reduction, visualization of the radial nerve and intramedullary nailing could be achieved with endoscopic control. There were no surgical complications such as secondary radial nerve palsy, hematomas or wound healing problems. With the use of the endoscope the number of secondary radial nerve palsies associated with intramedullary humeral shaft nailing might be reduced in the future.

Adult↗
PubMed2005

[Prosthetic care of proximal femur fractures].

The endoprosthetic replacement of the hip joint or its components in fractures of the proximal femur is a standard method. Indications for replacement are strongly dislocated intracapsular femoral neck fractures in elderly patients, fractures with an existing arthritis of the hip joint, and profound osteoporosis. Improved perioperative management and more gentle anesthetic techniques have helped to reduce perioperative mortality from nearly 50% to 11.5% over the last 40 years. As routine treatment options, the bipolar endoprosthesis without replacement of the acetabular joint surface and total hip replacement in case of degenerative arthritis of the acetabular joint surface are commonly used. The mere replacement of the femoral head with a simple femoral head prosthesis should be reserved for exceptional cases. For the implantation of a hip joint prosthesis and its uncomplicated post-treatment and long-term durability, careful preoperative planning is essential together with the selection of a suitable implant, its optimal bony fixation, avoidance of intra-operative complications and restoration of the anatomical landmarks such as the centre of rotation of the hip joint, the offset of the prosthetic shaft as well as leg length. Despite the high standard of endoprosthetics in Germany, the results are still improvable in comparison to other countries. Measures which preserve the joint as well as the bone will be increasingly important in prophylaxis of further complications. In addition, more attention should be paid to the prophylaxis of falls and a sufficiently guide-lined therapy of osteoporosis for the prophylaxis of fractures of the elderly.

Arthroplasty, Replacement, Hip↗