[Thiel method fixed cadaver ears. A new procedure for graduate and continuing education in middle ear surgery]. / Nach Thiel fixierte Leichenohren. Ein neues Verfahren für die Aus- und Weiterbildung in der Mittelohrchirurgie.

BACKGROUND AND OBJECTIVE: An efficient training program in ear surgery needs suitable models to learn the specific preparation techniques. However, conventionally fixed or fresh frozen ears of human corpses do not meet all demands. Therefore we investigated the feasibility of ears fixed according to Thiel for surgical training in the temporal bone lab. METHODS: Various surgical techniques on external and middle ears were evaluated on ears from cadavers fixed according to Thiel. Structure and consistency of the tissues were compared to vital conditions by means of a standardized questionnaire. RESULTS: Structure and consistency of the tissues of the auditory canal, the tympanic cavity and the mastoid were comparable to vital conditions. Merely the cartilage of the auricle was considerable softened. This enabled a surgical preparation under conditions close to the intravital situation. CONCLUSIONS: Under the aspects of quality assurance and efficiency of continuous medical education in middle ear surgery, the Thiel fixation technique provides an excellent prerequisite.

Interindividual reproducibility in perioperative rotational alignment of femoral components in knee prosthetic surgery using the transepicondylar axis.

Femoral component malalignment is one of the main causes of persisting anterior knee pain after knee replacement. This study examined interindividual reproducibility in perioperative definition of the transepicondylar axis (TEA) as a reference for measuring the rotational alignment of the femoral component. Eight surgeons experienced in knee prosthetic surgery marked on Thiel-embalmed cadaver specimens the reference points that they would normally use to define the TEA during knee replacement. These were digitized by a video system, and all the spots defined by the surgeon were translated into a reference picture, allowing a digital analysis of the distances between all the spots marked. The maximal distance between the spots that the participants had marked as relevant for the TEA was 13.8 mm at the lateral and 22.3 mm at the medial epicondyle. Projecting all spots marked into one picture resulted in an area of 116 mm2 on the lateral and 102 mm2 on the medial epicondyle. The median range of the fault between two different participants was 6.4 mm on the lateral side (range 13.2 mm) and 9.7 mm on the medial (range 21.6 mm). Because the rotational alignment of the femoral component is extremely relevant for successful implantation of total knee prosthesis, the interindividual discrepancy in defining the TEA as reference is rather high. As this reference line is commonly used, the perioperative variance and the resulting rotational discrepancy of the femoral component must be considered.

[Basic principles and surgical technique of tibio-fibula-plasty in cartilage-bone transplantation]. / Grundlagen und Operations-technik der T(ibio)-F(ibularen)-Plastik zur Knorpelknochen-transplantation.

BACKGROUND: Within the last few years autologous cartilage-bone-grafting is becoming an established standardized procedure in joint surgery. One significant disadvantage of this technique is the harvesting of the bone plugs from the weight-bearing area of the knee joint. PURPOSE: The tibiofibular articulation is located close to the knee joint that is operated on. This articulation is covered with cartilage. The purpose of this study was to evaluate the question, whether this joint is suitable as a donor site for bone-cartilage transplants. MATERIAL AND METHODS: Favourable approaches and committing of anatomical landmarks were investigated on 44 fixed tibiofibular joints. In knee extension, the shortest distance between the joint cleft and common fibular nerve was measured. The cartilage thickness and histology of both the fibular and tibial joint surface were documented. The developed surgical approach was evaluated in patients. RESULTS: Histological and immunohistochemical examination showed hyaline cartilage and type II collagen. The average cartilage thickness was 1.9 +/- 0.29 mm (minimum: 1.5 mm; maximum: 2.6 mm). The peroneal nerve showed an average distance to the tibiofibular joint of 24 mm (minimum: 12 mm; maximum: 30 mm). Different surgical procedures are possible and clinical relevant. CLINICAL RELEVANCE: The tibiofibular joint contains cartilage, which may be a reasonable donor site even for the elderly patient. Harvesting the graft from this area may avoid iatrogenic damaging of intraarticular weight bearing cartilage of the knee joint.

Which joint position puts the axillary nerve at lowest risk when performing arthroscopic capsular release in patients with adhesive capsulitis of the shoulder?

The success of arthroscopic capsular release of the glenohumeral joint depends on complete incision of the inferior capsule. This study determined the distance between capsule and the axillary nerve in different joint positions. In 14 human shoulder specimens the anterior joint capsule and axillary nerve were dissected, and the anterior joint capsule was incised between the 1 and 5 o'clock positions. The shortest distance between the insertion of the inferior capsule and the axillary nerve was measured at the glenoid and humeral insertions in abduction, adduction, internal, and external rotation. The axillary nerve is surrounded from soft connective tissue and is closer to the humeral than to the glenoidal attachment of the joint capsule. During abduction and external rotation the nerve stays in its position while the glenohumeral capsule tightens, which increases the distance between the two structures. This results in the following distances: to the glenoidal/humeral capsule insertion: in adduction and neutral rotation, 21.2+/-4.2/14.2+/-2.6 mm; in abduction and neutral rotation, 24.0+/-4.9/15.0+/-5.0 mm; in abduction and internal rotation, 21.1+/-6.6/14.6+/-3.7 mm; and in abduction and external rotation, 24.9+/-3.8/16.4+/-4.4 mm. Thus, when performing arthroscopic capsular release the incision of the glenohumeral joint capsule should be undertaken at the glenoidal insertion in the abducted and externally rotated shoulder.

The posterior subdeltoid approach: a modified access to the posterior glenohumeral joint.

A modified surgical approach to the posterior aspect of the glenohumeral joint and/or the dorsal glenoid is described. This access does not alter any muscle insertion or neuromuscular planes. After the skin incision is made, the inferior border of the spinal part of the deltoid is identified and the deltoid muscle is mobilized and retracted, thus offering an excellent approach to the interval between the infraspinatus and teres minor muscles. This interval is split parallel to the muscle fibers. This surgical approach was first established in 10 cadaverous shoulders and then performed in 12 patients with posterior shoulder pathology. In the cadaver study, the closest distance to the axillary nerve with this approach was 22 mm. In all 12 cases, the surgical procedure could be performed without any problems.

Entrapment of the lingual nerve due to an ossified pterygospinous ligament.

During a routine dissection course at the University of Muenster (Germany) an unusual course of the lingual nerve was found with entrapment of the nerve between a widely ossified pterygospinous ligament and the medial pterygoid muscle. Furthermore, the nerve's mobility was restricted by a more distal anastomosis with the inferior alveolar nerve. Although incomplete or complete ossification of the pterygospinous ligament is not uncommon, the combination with a medial course of the lingual nerve has not been described before. Besides practical importance for surgeons and anesthetists, the entrapment of the lingual nerve may lead to lingual numbness and pain associated with speech impairment.

[Surgical procedures in mouth, jaw and facial surgery in Thiel embalmed body donors]. / Operative Verfahren der Mund-, Kiefer- und Gesichtschirurgie an nach Thiel fixierten Körperspenden.

METHODS: This study investigates whether human cadavers embalmed according to Thiel can be used for research and education in oral-maxillo-facial surgery. Different surgical approaches were tested on such cadavers. The usability of the specimen was judged jointly by anatomists and surgeons. Color, structure, and consistency of the different tissues were comparable to vital conditions. Thiel's embalming technique applied to human cadavers provides an optimal basis for research and for basic and postgraduate medical education.

[Pathomorphology of laser-induced interstitial tumor thermotherapy of the liver]. / Pathomorphologie der Laser-induzierten interstitiellen Tumor-Thermotherapie an der Leber.

The aim of this study was to analyse pathomorphological findings after treatment with laser induced tumor thermotherapy (LITT) on liver tissue and to correlate the results with magnetic resonance imaging. LITT was performed ex vivo and in vivo using a Neodym-YAG-Laser. Lesions were monitored by MR-thermometry ex vivo and by contrast-enhanced MRI in vivo. After LITT the lesions were examined macroscopically, histologically, and electronmicroscopically. LITT-induced tissue damage was qualitatively evaluated, classified, and quantified by means of digital image analysis. Four different zones of tissue damage were identified within the lesions. Adjacent to the applicator the tissue was completely ablated while more peripheral lesions exhibited only sublethal cell damages seen by EM. In vivo the pattern of tissue injury followed the lobular architecture of the liver tissue. Ultrastructural examination revealed only in areas of minor tissue injury intact sinusoidal patterns. MRI overestimated the diameter of the core zone of complete tissue ablation both ex vivo and to a lesser extent in vivo.

Rare but serious complications of acupuncture: traumatic lesions.

Acupuncture has a reputation among the public of being safe. Although recently performed prospective studies on the frequency of adverse effects of acupuncture found no severe complication, since 1965 many case reports of serious or even life-threatening incidents caused by acupuncture have appeared in the scientific literature. The most frequently reported complications are pneumothorax and lesions of the spinal cord. Severe injuries of peripheral nerves and blood vessels due to acupuncture seem to be very rare. Although case reports do not produce reliable data on the frequency of adverse events. information on sources of application errors can be extracted to increase the quality of acupuncture in education and therapy. All traumatic injuries described in this article could be avoided if practitioners had better anatomical knowledge, applied existing anatomical knowledge better, or both.

[Precision and comparison of CT-, MRI- and DL-controlled interventions exemplified by lumbar facet infiltration--an experimental study]. / Präzision und Vergleich von CT-, MR- und DL-gesteuerten Interventionen am Beispiel der lumbalen Facetteninfiltration--eine experimentelle Untersuchung.

We evaluated the accuracy of the needle tip representation by different imaging techniques for the guidance of facet infiltrations. For visualisation of the lumbar facet joints we used a high-field magnetic resonance tomograph (MRT) with a 2.0 Tesla field and 3.5 mm slice thickness, an open low-field magnetic resonance tomography (MRT) with an 0.064 Tesla field and 9 mm slice thickness, and IMATRON electron beam computed tomograph (EBCT) with a slice thickness of 6 mm, and a mobile C-arm fluoroscope. The study was performed on 4 human cadaveric lumber spine preparations, each of which had 8 facet joints. Under imaging control, special injection needles were placed as close as possible to the facet joint space. Following placement of he needle, all specimens were scanned with the electron beam tomograph using a slice thickness of 1.5 mm. The thin-slice study served as the gold standard. The distance between the tip of the needle and the facet joint was measured in all the images. Comparison of the different modalities with the gold standard revealed the following results: 1) median values of the absolute differences were 1.25 mm for high-field MRI, 1.35 mm for 6 mm EBCT, 2.05 mm for low-field MRI, and 2.30 mm for X-ray fluoroscopy. 2) While there was no statistically significant difference in the accuracy of tip localization between high-field MRI and 6" EBCT (p = 0.293), both systems were more precise than low-field MRI (p = 0.04) and X-ray fluoroscopy (p = 0.009). When choosing the best imaging technique, such additional factors as radiation, costs and time, must also be considered. Provided necessary radiological precautions are taken, and assuming careful pre-interventional planning, CT. EBCT and X-ray fluoroscopy are currently more effective than the expensive, time-consuming and costly magnetic resonance tomography.

Is there an option for harvesting autologous osteochondral grafts without damaging weight-bearing areas in the knee joint?

Within the past few years autologous osteochondral transplantation has become an established standardized procedure in joint surgery. One significant disadvantage of this technique is the harvesting of the osteochondral grafts from the weight-bearing area of the knee joint. The tibiofibular articulation is located close to the knee joint that is operated on. This articulation is covered with cartilage. The purpose of this study was to evaluate whether this joint is suitable as a donor site for osteochondral grafts. Ten human knee specimens were freed of all soft tissues around the proximal calf. The age of the specimens ranged between 58 and 79 years. Next the tibiofibular articulation was identified, and both the ligaments and the capsule were removed. After opening the joint the tibial- and fibular-sided joint surfaces were inspected and measured. In all specimens the articular surfaces showed good cartilage coverage. In only a single joint did the cartilage macroscopically show degeneration. In all other joints the cartilage surface was in surprisingly good condition, especially considering the age of the specimens. The average diameter of the cartilage surface on the tibial side was 1.7 +/- 0.26 x 1.9 +/- 0.22 cm and on the fibular side 1.6 +/- 0.31 x 1.8 +/- 0.32 cm. This results in an area of cartilage for transplantation of 3.23 cm2 at the tibia and of 2.88 cm2 at the fibula. The total area for cartilage transplantation is 6.11 cm2. The tibiofibular joint contains cartilage, which may be a reasonable donor site even for the elderly patient. Harvesting the graft from this area may avoid iatrogenic damaging of intra-articular weight-bearing cartilage of the knee joint.

[Virtual simulation for optimizing the range of motion in hip alloarthroplasty using an adapted thrust-plate prosthesis model]. / Virtuelle Simulation zur Optimierung des Bewegungsspiels einer Hüftalloarthroplastik am Beispiel der adaptierten Druckscheibenprothese.

The purpose of the present study was to increase the free range of motion in conventional trust-plate prosthesis design and to optimize the trust-plate contact as well as the osteointegration area below the trust-plate. For the first part of the study, the two-dimensional geometry of the osteotomy plane was demonstrated in 25 CT-reconstructed femora after performing a virtual cut at a CCD angle of 135 degrees. In the second part, we constructed a prototype of an anatomic adapted trust-plate prosthesis (A-TPP) with an optimized trust-plate and corpus geometry based on the three-dimensional data of three human cadaveric femurs (age 67-75 years). In the final step, we documented the range of motion with computer-aided movement-mapping and compared the conventional TPP with the A-TPP. The results showed a wide variance in osteotomy geometry in the 12 femurs. With the A-TPP, we were able to obtain a much better fit in the trust plate surface. The movement-mapping showed a much higher range of motion in the A-TPP implant. With the A-TPP, the implant surface area for osteointegration could also be significantly increased.

Vitamin E reduces platelet adhesion to human endothelial cells in vitro.

Although it has been reported that vitamin E (alpha-tocopherol) can reduce platelet adhesiveness and aggregation in vivo, the mechanism is still unknown. Therefore, the aim of the present study was to determine whether incubations of platelet-rich plasma (PRP) with vitamin E influence platelet adhesion to cultured endothelial cells. To exclude blood plasma involvement, also washed platelets were pretreated with alpha-tocopherol. Vitamin E (0.5-1.0 mM) was added to PRP or washed platelets. Endothelial cells in monolayer were incubated with thrombin-activated platelets (1 or 2 U/ml). After 1 hr of incubation, non-adhered platelets were removed and counted. Treating of PRP with alpha-tocopherol inhibited platelet adhesion to endothelial cell monolayer. This effect was dose dependent on concentrations of alpha-tocopherol and thrombin. In our experiments PRP was treated with alpha-tocopherol and endothelial cell monolayer was used as test surface. These findings agree with previous observations on the adhesivity of platelets to synthetic surfaces after dietary vitamin E in healthy volunteers. When washed platelets were incubated with alpha-tocopherol, no significant reduction of adhesion was detectable. As preincubation of washed platelets with alpha-tocopherol does not inhibit platelet adhesion, it may be supposed that the effect of vitamin E does not occur in a directly cellular mechanism. The data suggest that alpha-tocopherol may reduce platelet adhesiveness probably after incorporation by plasma lipoproteins.

Reflection contrast microscopy (RCM): a forgotten technique?

Reflection contrast microscopy (RCM), which utilizes the optical phenomena caused by oblique epi-illumination in combination with a specific optical apparatus, provides an approach for exploring biological phenomena in greater detail. The lack of stray reflection makes it superior to other microscopes. It bridges light and electron microscopic capabilities by allowing the analysis of ultrathin sections beyond the usual light microscopic magnification. By using consecutive image analysis, quantitation can be achieved. The wide range of applications of RCM can be combined with most microscopical techniques, so extending the spectrum of information that can be gathered. Twenty-five years after the development of RCM, there is still scope for its application in modern cell biology.

Live interdisciplinary teaching via the internet.

The independence of teachers and students is one of the main advantages of teleteaching. Specialties considered unsuitable for combined lessons are manageable using the internet. This study outlines simultaneous communication with students and lecturers over long distances between the anatomical dissection laboratory, the operating theatre, and the lecture hall. In several three-directional on-line lectures, different equipment was used. Students could also participate using personal computers from other locations. During the presentations, the participants have the opportunity to discuss problems with any lecturer. It was possible to demonstrate sufficient transmission capability for real-time application with the use of the new internet technology. No important qualitative differences can be reported between: hardware and software based solutions; or commercial and free offers. Although it is often difficult to reconcile the timetable of surgeries and lectures, multimedia on-line teaching via the internet provides new potential for interdisciplinary medical education.

Computer assisted implantation of the femoral stem in THA - an experimental study.

Fourteen femoral stems were implanted either manually by an experienced surgeon or by a robot in fresh human cadaveric femora. The neck-shaft angle, the anteversion, the length of the femoral neck and the gap between stem and bone was measured in each specimen. Implantation by robot showed higher precision in reconstructing the true anatomic situation as well as providing a better press fit.

[New paths for Internet generated learning in anatomy]. / Neue Wege der Internet-gestützten Lehre in der Anatomie.

For the purposes of a functioning information and knowledge based medicine the conditions for the medical education are crucial. Although multimedia based courses and tutorials via the Internet seem to serve best for a more effective teaching and new didactics, respective anatomical offers in Germany are scarce and thus practice and experience are limited. Only simple digital equivalents of conventional contents and methods can be found, whereas the potencies of the new media are not realized in didactic concepts. Substantial advantages of web based tutorial systems are an intensive use of the feedback possibilities, the opportunity for continuous updating of the contents, the favourable distribution, and faster utilization of improved techniques. This paper introduces the adaptation of different techniques and the development of concepts and notions of modern Internet based teaching by the way of three different events in anatomical education for medical students and doctors. HistoNet 2000 was developed as an interface of lectures, seminars and practical courses in microscopy. The online transmission of a microscopical course as an interactive practical teleteaching was performed by the way of asymmetric data transfer via the ADSL-technology. Multicasting was used as well and has also been applied for the third project. In this multimedial online teaching different specialties were joined together for interdisciplinary courses via the Internet. These new technologies lead to enhanced efficiency in teaching and enlarge the educational offer. Specific Internet adapted teaching and learning projects have to be developed.