[Stabilization of the pelvic ring with photodynamic bone stabilization (IlluminOss™)]. / Stabilisierung einer Beckeninsuffizienzfraktur mit einem photosensiblen Kunststoff (IlluminOss™).

We describe the case of an 88-year-old woman who presented with painful symptoms of the pelvis after low-energy trauma. Conservative treatment with pain therapy and pain-adapted mobilization was unsuccessful. Diagnostics showed a fragility fracture of the pelvic ring; therefore, we performed photodynamic bone stabilization (IlluminOss™) of the pubic bone and percutaneous cement-augmented fixation of the iliosacral joint assisted by computed tomography (CT) fluoroscopy. Imaging showed a stable healed fracture 4 months after surgery.

[Psoas haematoma due to irritation of the psoas tendon]. / Psoashämatom bei Iliopsoaskontaktphänomen.

Irritation of the tendon of the musculus iliopsoas after total hip replacement is a rare complication. In connection with the irritation of the iliopsoas tendon only one case report of a psoas haematoma due to anticoagulation has been published. We assume that these kinds of haematomas are more frequent than described. We report on 2 cases of haematoma caused by an iliopsoas impingement after total hip replacement. In one case a lesion of the femoral nerve was observed. Surgical treatment was composed of the revision of the acetabular component.

[Diagnosis specific differences in knee joint geometry. A challenge for the correct axial implantation of long stems in total knee arthroplasty]. / Diagnosespezifische Unterschiede der Kniegelenkgeometrie. Herausforderung bei der achsgerechten Implantation langstieliger Kniegelenkendoprothesensysteme.

BACKGROUND: Arthrotic deformities with changes in knee geometry can produce difficulties in implanting long stem knee prosthesis systems using intramedullary alignment. They can result in incorrect lower limb axis and prosthesis positioning. The aim of the presented study was to measure knee geometry in patients with varus and valgus gonarthrosis in order to define diagnosis related differences. METHODS: A total of 75 patients with indication for total knee arthroplasty were divided in two groups using the weight bearing lower limb axis: patients with varus gonarthrosis (n=43) and with valgus gonarthrosis (n=32). Angles and extensions, important for knee prosthesis implantation, were measured, digitalized and analyzed. The results were investigated for diagnosis specific differences. RESULTS: After regulation of the measured extension in mean femur/tibia lengths, significant diagnosis specific differences were found: femur condyles were widened towards pathologic weight bearing (P<0.044), and the mechanical tibia axis of the varus gonarthrosis group is transferred to the lateral side (P<0.046) and in projection over the lateral internal cortical substance. CONCLUSION: The significant differences in deformed arthrotic knees indicate that for an optimal postoperative result the use of standard implants is not always sufficient. Modular knee prosthesis systems can provide adequately for individual demands.

Atlas-based recognition of anatomical structures and landmarks and the automatic computation of orthopedic parameters.

OBJECTIVE: This paper describes methods for the automatic atlas-based segmentation of bone structures of the hip, the automatic detection of anatomical point landmarks and the computation of orthopedic parameters to avoid the interactive, time-consuming pre-processing steps for the virtual planning of hip operations. METHODS: Based on the CT data of the Visible Human Data Sets, two three-dimensional atlases of the human pelvis have been built. The atlases consist of labeled CT data sets, 3D surface models of the separated structures and associated anatomical point landmarks. The atlas information is transferred to the patient data by a non-linear gray value-based registration algorithm. A surface-based registration algorithm was developed to detect the anatomical landmarks on the patient's bone structures. Furthermore, a software tool for the automatic computation of orthopedic parameters is presented. Finally, methods for an evaluation of the atlas-based segmentation and the atlas-based landmark detection are explained. RESULTS: A first evaluation of the presented atlas-based segmentation method shows the correct labeling of 98.5% of the bony voxels. The presented landmark detection algorithm enables the precise and reliable localization of orthopedic landmarks. The accuracy of the landmark detection is below 2.5 mm. CONCLUSION: The atlas-based segmentation of bone structures, the atlas-based landmark detection and the automatic computation of orthopedic measures are suitable to essentially reduce the time-consuming user interaction during the pre-processing of the CT data for the virtual three-dimensional planning of hip operations.

Limb salvage with tumor endoprostheses for malignant tumors of the knee.

Data of 64 consecutive patients with malignant tumors of the knee treated with tumor endoprostheses between 1976 and 1996 were reviewed. The study was retrospective before 1990 and prospective since then. Four patients were lost to followup and are not included in the study. The average age of the remaining 60 patients was 33.2 years (range, 9-72 years). Fifty patients had surgery for primary sarcoma and 10 patients had surgery for metastases of carcinoma. In the patients in the sarcoma group, the probability of 5 years survival was 72% and 10 years survival was 69%. The overall clinical score of 47 patients with a followup more than 9 months was 81% using the evaluation system of the International Society of Limb Salvage. Fifty-eight reoperations were done in 29 patients because of complications. Twenty reoperations were attributable to soft tissue complications, 34 reoperations were because of mechanical problems related to the prostheses, and four were because of local tumor recurrence. The probability of survival of the leg of the patient after 10 years was 95%. Despite a high rate of complications after limb salvage with endoprostheses, the final clinical outcome usually was good.

[Iliopsoas impingement after cementless total hip arthroplasty. Case reports]. / Iliopsoaskontaktphänomen nach zementfreier Hüfttotalendoprothese. Eine Fallbeschreibung.

Postoperative pain after total hip arthroplasty can be caused by several conditions. We describe two cases of postoperative persistent iliopsoas impingement after cementless implantation of the acetabular component. The groin pain was relieved after revision with a more anteverted acetabular component. We describe the diagnostic methods as well as the principles of the revision.

Atlas-based segmentation of bone structures to support the virtual planning of hip operations.

Two 3-D digitised atlases of a female and a male pelvis were generated to support the virtual 3-D planning of hip operations. The anatomical atlases were designed to replace the interactive, time-consuming pre-processing steps for the virtual operation planning. Each atlas consists of a labelled reference CT data set and a set of anatomical point landmarks. The paper presents methods for the automatic transfer of these anatomical labels to an individual patient data set. The labelled patient data are used to generate 3-D models of the patient's bone structures. Besides the anatomical labelling, the determination of measures, like angles, distances or sizes of contact areas, is important for the planning of hip operations. Thus, algorithms for the automatic computation of orthopaedic parameters were implemented. A first evaluation of the presented atlas-based segmentation method shows a correct labelling of 98.5% of the bony voxels.

Three-dimensional planning and simulation of hip operations and computer-assisted construction of endoprostheses in bone tumor surgery.

OBJECTIVE: This article presents the VIRTOPS (VIRTual Operation Planning in Orthopaedic Surgery) software system for virtual preoperative planning and simulation of hip operations. The system is applied to simulate the endoprosthetic reconstruction of the hip joint with hemipelvic replacement, and supports the individual design of anatomically adaptable, modular prostheses in bone tumor surgery. The virtual planning of the operation and the construction of the individual implant are supported by virtual reality techniques. The central step of the operation planning procedure, the placement of the cutting plane in the hip bone, depends strongly on the tumor's position. Segmentation of the tumor and the bones in MR and CT data, as well as fusion of MR and CT image sequences, is necessary to visualize the tumor's position within the hip bone. MATERIALS AND METHODS: Three-dimensional models of the patient's hip are generated based on CT image data. A ROI-based segmentation algorithm enables the separation of the bone tumor in multispectral MR image sequences. A special registration method using segmentation results has been developed to transfer CT and MR data into one common coordinate system. During the 3D planning process, the surgeon simulates the operation and defines the position and geometry of the custom-made endoprosthesis. Stereoscopic visualization and 3D input devices facilitate navigation and 3D interaction in the virtual environment. Special visualization techniques such as texture mapping, color coding of quantitative parameters, and transparency support the determination of the correct position and geometry of the prosthesis. RESULTS AND CONCLUSIONS: The VIRTOPS system enables the complete virtual planning of hip operations with endoprosthetic reconstruction, as well as the optimal placement and design of endoprostheses. After the registration and segmentation of CT and MR data, 3D visualizations of the tumor within the bone are generated to support the surgeon during the planning procedure. In the virtual planning environment, individually adapted endoprostheses can be constructed without the need to generate expensive solid 3D models. Furthermore, different operation strategies can be compared easily. Three-dimensional images and digital movies generated during the virtual operation planning can be used for case documentation and patient information purposes.

Simulation of hip operations and design of custom-made endoprostheses using virtual reality techniques.

In this paper a system for the virtual planning of hip operations with endoprosthetic reconstruction and its application in bone tumor surgery is described. The system enables the simulation of the operation and the construction of a custom-made implant depending on the chosen resection planes and the patient's anatomy. During the planning process integrated virtual reality techniques facilitate the interaction with the three-dimensional (3D) medical objects. Stereo viewing improves the perception of the 3D nature of bone structures and tumors. In comparison to conventional planning procedures, different operation strategies and their influence on the geometry of the custom-made endoprosthesis can be easily compared. Furthermore, the combination of multi-modal image information (CT and MR) enables an accurate 3D visualization of the bone tumor within the bone.

Modified dorsalis pedis flap for coverage of a pretibial pressure sore after hip rotationplasty.

Rotationplasty is a well-established procedure after total femur resection, especially in children. Rehabilitation is superior to disarticulation of the hip or hemipelvectomy because patients regain hip and knee function.(1) A tight fit of the prosthetic shaft is essential. The pretibial area has a low physiological resistance to pressure and shear forces, and is thus at increased risk of developing pressure-related complications. Skin defects with exposure of skeletal elements require flap coverage. The dorsalis pedis flap is one of the surgical options available for skin coverage of the proximal anterior leg. It can be rotated to cover almost any site on the anterior aspect of the leg if the pedicle is mobilised up to the anterior tibial artery.(2)Since donor site complications are common, this flap has few indications.(3)

The interaction of human peripheral blood eosinophils with bacterial lipopolysaccharide is CD14 dependent.

Bacterial lipopolysaccharide (LPS, endotoxin) is a ubiquitous component of dust and air pollution and is suspected to contribute after inhalation to an activation of eosinophils in bronchial tissues of asthmatic patients, provoking inflammatory and allergic processes. We were therefore interested in the interaction of eosinophil granulocytes with LPS and have examined the activation of and uptake to human peripheral blood eosinophils by LPS. Eosinophils were stimulated by LPS and the endotoxic component lipid A and the release of tumor necrosis factor alpha (TNF-alpha) and of the eosinophil-specific granule protein eosinophil cationic protein (ECP) was estimated. The results show induction of TNF-alpha and ECP-release by LPS and lipid A in a dose-dependent manner. Anti-CD14 monoclonal antibody (moAb) (clone MEM-18) and the synthetic lipid A partial structure 406 blocked the release of TNF-alpha and ECP by LPS-stimulated eosinophils. Studies with radioactively labeled LPS showed dose-dependent uptake of (3)H-LPS to eosinophils. The (3)H-LPS uptake was found to be specific because preincubation with unlabeled LPS, compound 406 and also anti-CD14 antibodies inhibited uptake of (3)H-LPS to eosinophil granulocytes. By flow cytometry using anti-CD14 moAb and by reverse transcriptase-polymerase chain reaction (RT-PCR) technique, CD14 expression was detectable. Furthermore, messenger RNA (mRNA) expression of Toll-like receptors (TLR) 2 and TLR 4 was detected, indicating the presence of these CD14 coreceptors. The results indicate that eosinophils can take up LPS and can be stimulated by LPS in a CD14-dependent manner. Hence, in addition to allergens, eosinophils interact with endotoxin, a process that possibly exacerbates ongoing inflammatory and allergic processes.

Virtual planning of hip operations and individual adaption of endoprostheses in orthopaedic surgery.

The introduction of virtual reality techniques in medicine opens up new possibilities for the planning of interventions. The presented software system for virtual operation planning in orthopaedic surgery (VIRTOPS) enables the virtual preoperative 3D planning and simulation of pelvis and hip operations. It is used to plan operations of bone tumours with endoprosthetic reconstruction of the hip based on multimodal image information. The operation and the endosprothetic reconstruction of the pelvis are simulated using virtual reality techniques. Stereoscopic visualisation techniques and 3D input devices support the 3D interaction with the virtual 3D models. The main task of the preoperative planning process is the individual design of an anatomically adaptable modular prosthesis. The placement and the design of the endoprosthesis are supported by different functions and visualisation techniques. The resulting 3D images and movies can be used for the documentation of the operation planning procedure, as well as, for the preoperative information of the patient.

An anatomical atlas to support the virtual planning of hip operations.

Two three-dimensional digitized atlases of a female and a male pelvis were generated to support the virtual 3D-planning of hip operations. Beside the anatomical labeling of bone structures the determination of orthopedic measures, like angles, distances or sizes of contact areas, is important for the planning of hip operations. Thus, each atlas consists of labeled reference CT data sets, a set of landmarks as well as definitions of orthopedic measures and methods for their automatic computation. Furthermore, methods for the automatic transfer of anatomical labels from the atlas to an individual data set are presented resulting in three-dimensional models of the patient's bone structures. The anatomical atlases are designed to replace the interactive, time-consuming pre-processing steps for the virtual 3D operation planning.

[New therapy procedure for localized cartilage defects. Encouraging results with autologous chondrocyte implantation]. / Neues Therapieverfahren für lokalisierte Knorpeldefekte. Ermutigende Resultate mit der autologen Chondrozytenimplantation.

Owing to the poor regenerative capacity of cartilage, cartilaginous defects are considered to represent pre-arthrotic factors. In addition to autologous and allogenic osteochondral fragments, proliferative tissue, such as periosteum and perichondrium are increasingly being used as graft material. The aim of treatment is to eliminate the defect and to restore the load-bearing capacity and function of the affected joint. A new, recently introduced, approach aims to stimulate the formation of new cartilage via autologous cultured chondrocyte implantation (ACI). The rationale for this treatment is the restoration of loadable hyaline or hyaline-like articular cartilage. Although long-term results are not yet available, clinical follow-up data obtained so far are encouraging. In addition to existing methods of treating cartilaginous defects, this article describes a modified method of transplantation of autologous chondrocytes. With this method the periosteal flap used to cover a defect is replaced by an absorbable collagenl/III membrane (Chondrogide, Geistlich Wolhusen, Switzerland) that is used as a carrier for the patient's own chondrocytes. After placement in the defect, the membrane is fixed in place with fibrin glue (MACI).

Computer-assisted planning and simulation of hip operations using virtual three-dimensional models.

In this paper a new software system for virtual preoperative planning and simulation of hip operations is presented. The system simulates the endoprosthetic reconstruction of the hip joint with hemipelvic replacement for bone tumor patients and supports the individual design of anatomically adaptable, modular prostheses. Three-dimensional models of the patient's hip are generated based on CT data. The surgeon simulates the operation and defines the position and shape of the custom-made endoprosthesis. Stereoscopic visualization and 3D input devices facilitate the navigation and interaction in the virtual environment. Special visualization techniques like texture mapping, color coding of quantitative parameters or transparency support the determination of the correct position and shape of the prosthesis. Furthermore, the system can be used for patient information or educational tasks.

[Surgical management of pelvic metastases]. / Operative Therapie von Beckenmetastasen.

Due to a rise in life expectancy as well as improved adjuvant and diagnostic measures the incidence of clinically symptomatic metastases has significantly increased. In terms of indication and operative technique in the treatment of these lesions the biologic age, general condition, diagnosis, stage and activity of the disease and the patient's prognosis are highly important. Different techniques of joint replacement have been described to treat patients suffering from metastatic disease of the periacetabular region, being resistant to any kind of adjuvant therapy. From 1977-1996 21 patients with a periacetabular lesion received a tumor prosthesis following internal hemipelvectomy (average age 60 years; average survival 23.1 months). Perioperative complication rate was 42%, functional results were good (n =), fair (n = 9) and poor (n = 2). Mobilisation and analgesia are the most important therapeutic goals. The quality of the patient's life postop is the major point.

Proteus syndrome with widespread portwine stain naevus.

Proteus syndrome is a rare condition comprising asymmetrical overgrowth of different parts of the body in association with various cutaneous abnormalities. We describe a 3-year-old boy with Proteus syndrome, who presented with hemihypertrophy of the right leg, asymmetric macrodactyly, subcutaneous masses and a widespread portwine stain interspersed with angiokeratomas on the right leg, scrotum and on the middle and left side of the back. Doppler ultrasound of the right leg did not show hypercirculation, but did reveal the absence of the right superficial femoral vein.

Mountain medicine education in Europe.

All educational programs in mountain medicine in Europe are presented with their history, evolution, and current status. A comparison and a summary of those programs, as well as an estimate of the number of doctors trained in mountain medicine, are offered. Special focus is put on new developments and subspecialty programs. All programs listed in the Union Internationale des Associations Alpinistes (UIAA) information papers and all programs known through different publications were contacted and asked to forward information about recent courses, materials from former courses, and program syllabi. This information was reviewed and different specific topics were developed in depth. There are 13 different programs in Europe offering medical education in mountain medicine: 3 in France; 2 each in Italy, Spain, and the United Kingdom; and 1 each in Switzerland, Austria, Germany, and The Netherlands. The duration of these courses varies from a long weekend to a full 3-week course with theoretical and practical instruction. At this moment, most programs still have different contents and structures, which are being standardized by the UIAA and the International Commission for Alpine Rescue Medical Commission (ICAR MEDCOM). At least 2600 doctors have had a first-contact course in high-altitude medicine, and at least 2000 have participated in a full course of 1 week of more. A large number of doctors in Europe have become acquainted with mountain medicine by participating in different medical education programs. These programs should be optimized and further specialized in the different areas of mountain medicine, including expedition, alpine, and rescue medicine.