[Determining the indication for primary total hip and knee replacement. Results of external quality assurance of over 270,000 primary total hip and knee replacements]. / Indikationsstellung in der primären Hüft- und Kniegelenkendoprothetik. Ergebnisse der externen Qualitätssicherung von über 270.000 primären Hüft- und Kniegelenkendoprothesen.

BACKGROUND: The German mandatory quality assurance programme collects data from all primary total hip and knee replacements. The quality of the indication is measured by clinical and radiological criteria. The results were analysed in terms of differences in establishing the indication subject to patient and hospital characteristics. MATERIALS AND METHODS: Data on more than 270,000 primary total hip and knee replacements that were operated in 2006 in Germany were analysed concerning differences in the quality of the indication subject to age, gender, hospital volume and density of population and hospitals (metropolitan vs rural areas). The statistical analysis was done by exact Fisher's test. RESULTS: The quality of the indication was statistically significantly better in men, patients 60 and older, in rural areas and in high volume hospitals (50 and more joint replacements per year). DISCUSSION: Data of this mandatory German quality assurance programme are useful to describe differences in medical care. The results are valid and complete. An exact analysis of the reasons for these differences is difficult though. Data focus is on quality assurance and represent only in-hospital results. CONCLUSION: Further analyses are necessary to ascertain whether the differences in quality of care are deficits or only variances in medical care.

Rates and odds ratios for complications in closed and open tibial fractures treated with unreamed, small diameter tibial nails: a multicenter analysis of 467 cases.

OBJECTIVE: A multicenter trial analyzed complications and odds for complications in open and closed tibial fractures stabilized by small diameter nails. DESIGN: Retrospective. SETTING: Four Level I trauma centers. PATIENTS: Four hundred sixty-seven tibial fractures were included in the study. There were fifty-two proximal fractures, 219 midshaft fractures, and 196 distal fractures. Breakdown into different AO/OTA groups showed 135 Type A fractures, 216 Type B fractures, and 116 Type C fractures. Two hundred sixty-five were closed fractures and 202 were open fractures. OUTCOME MEASUREMENTS: Clinical and radiographic analysis. METHODS: 467 patients' tibial fractures were stabilized with small diameter tibial nails using an unreamed technique. Indications for the use of small diameter tibial nails using an unreamed technique included all types of open or closed diaphyseal fractures. The operating surgeons decided whether or not to ream based on personal experience, fracture type, and soft-tissue damage. Surgeons of Center 1 preferred to treat AO Type A and B fractures with unreamed nails, and surgeons of Centers 2, 3, and 4 preferred to treat AO Type B and C fractures with unreamed nails. Closed and open fractures were treated in approximately the same ratio. RESULTS: Analysis showed five (1.1 percent) deep infections (with a 5.4 percent rate of deep infections in Gustilo Grade III open fractures), forty-three delayed unions (9.2 percent), and twelve (2.6 percent) nonunions. Compartment syndromes occurred in sixty-two cases (13.3 percent), screw fatigue in forty-seven cases (10 percent), and fatigue failure of the tibial nail in three cases (0.6 percent). CONCLUSIONS: Fracture distraction of more than three millimeters should not be tolerated when stabilizing tibial fractures with unreamed, small-diameter nails as this increases the odds of having a delayed union by twelve times (p < 0.001) and a nonunion by four times (p = 0.057). There was a significant increase of complications in the group of Grade III open fractures (p < 0.001), AO/OTA Type C fractures (p = 0.002), and to a lesser extent in distal fractures. However, the rate of severe complications resulting in major morbidity was low.

The German approach to emergency/disaster management.

Disaster control and disaster relief in Germany are public tasks. But the government has shifted the responsibility of the administration of these tasks to the 16 states, the so called "Lander", because the EFG is a federal republic. The same is valid for the civil defense and the civil protection in the case of military or international risks. The 16 states are also responsible for the legislation of rescue service, fire fighting service and disaster control (natural and technical disasters). Counties and district-free cities are responsible for the organisation of these services. The German system is based on the principle of subsidiary between official and private institutions. A lot of official and private relief organisations are responsible for the execution of disaster relief tasks. In Germany the following organisations exist: Official (GO): Technisches Hilfswerk (THW/Federal Technical Support Service), Feuerwehren (Fire Brigades/professionals and volunteers) Academie of Emergency Planning and Civil Defense Private (NGO): Arbeiter-Samariter-Bund Deutschland (ASB/Workers' Samaritan Association Germany), Deutsche Gesellschaft zur Rettung Schiffbruchiger (DGzRS, German Lifesaving Association), Deutsches Rotes Kreuz (DRK/German Red Cross), Johanniter-Unfall-Hilfe (JUH/St. John's Ambulance), Malteser Hilfsdienst (MEID/Maltese-Relief-Organisation). ASB, DRK, JUH and MHD are specialised in the field of rescue, medical and welfare services and medical disaster relief. 80% of the German rescue service and 95% of the German disaster medical relief are realised by these NGO's. NGO's and GO's employ more than 1.2 million volunteers and appr. 100,000 professionals. Rescue service is carried out by professionals, disaster relief by volunteers. The German constitution allows to call the federal army in case of disaster, to support the disaster relief organisations (for example: flood Oder River 1997, train-crash "ICE" 1998). In all counties and district free cities disaster control staffs are set up by the administration. During disaster relief operations a operational command is on site. Most of the counties and district free cities, medical executives, rescue staff executives along with fire executive officers are responsible for the medical rescue organisation. All emergency physicians and medical executives have attended special training or a 520 hours-training-course (Paramedics). All volunteers of the medical service in the disaster relief organisations are trained in separate special courses (90 hours). Over the last years, civil protection, disaster relief and rescue services in the FRG have been reorganised. In 1997, the civil protection was reformed by a new federal act. Disaster relief of the "Lander" is supported by Federal Government with about 9000 vehicles and a budget for training. Emergency physicians have to take part in a (80) eighty hours lasting course on emergency medicine from an interdisciplinary point of view; they are only allowed to do rescue missions after having proved basic experience in emergency medicine as well as having completed a (18) eighteen-months-postgraduate training period at least. Senior emergency physicians receive and additional (40) forty-hours-lasting theoretical and practical training-after three years practice in rescue services as a minimum. There are special training courses offered for Medical and Non-Medical Personal to cope with disaster situation by different institutions and organisations.

[Studying minimally invasive osteosynthesis methods for distal radius fractures. Intra-focal vs. conventional wire osteosynthesis]. / Untersuchungen zu minimalinvasiven Osteosyntheseverfahren bei distalen Radiusfrakturen. Intrafokale versus konventionelle Bohrdrahtosteosynthese.

From 1992 to 1995 126 patients were treated with percutaneous wire pinning. Sixty-one patients were treated by Kapandji's technique and 65 patients were treated conventionally. Forty-nine patients were examined by 3 different scores (Cooney, Castaing, Stewart). The analysis of the scores showed no differences between the Kapandji technique and the conventional method. Functional and radiological results showed no correlation. Furthermore we found out that the results depend on the score. We conclude that the Kapandji technique shows no benefit in comparison to the conventional method. Functional and radiological results are not divisible: a conclusion from X-ray to function and vice versa is not allowed. A comparison of results is senseless if someone does not use the same score.

[Rare case of isolated trapezius fracture]. / Der seltene Fall einer isolierten Trapeziumfraktur.

This is a report of a rare case of an isolated fracture of the trapezium. Origin, diagnosis, differential diagnosis, treatment and complications are evaluated and described.

[Chronic inflammation 30 years after tibial intramedullary nailing--foreign body reaction or bacterial infection?]. / Chronische Entzündung 30 Jahre nach Tibiamarknagelung--Fremdkörperreaktion oder bakterielle Infektion?

30 years after two-fold marrow nailing of the tibia due to the formation of a pseudarthrosis and timely removal of the implants in a miner who was 17 years of age at that time, we found a chronic irritation that required surgical therapy. After excision of a two inch long sequester and escape of a small and cheesy core without identification of germs the patient is symptom-free since one and a half year. A foreign-body reaction to corrosion products of the implant or a late infection with low-virulent germs of the bradytrophic medullary callus appears to be the underlying cause.

Isolation of vascular endothelial cells for investigations on hybrid prostheses.

Hybrid vascular prostheses are coated with vascular endothelial cells (EC) in an attempt to reduce thrombogenicity through the metabolic activities of living cells. The present studies were planned to develop a standardized method of isolating bovine aortic EC with high yield for studies of endothelial coating of vascular prostheses. The best results were achieved using a combination of incubation with collagenase and mechanically scraping the mobilised cells from the donor vessel. Isolated adult male bovine endothelial cells were identified by the typical "cobble stone" morphology in culture and characterized by factor VIII related antigen immunofluorescence microscopy. The cells were seeded successfully on PTFE vascular prostheses.

Use of hepatocytes in adhesion and suspension cultures for liver support bioreactors.

Hepatocyte cultivation in bioreactors for hybrid liver support systems is possible under two conditions: attached to a substrate like membranes or microcarriers or in suspension culture. To compare the ammonia metabolism of hepatocytes cultivated under these two conditions, cultures of primary seeded rat hepatocytes were cultivated either attached to collagen coated tissue culture plastic or as a suspension culture. During the time course of culture, the ability of hepatocytes to reduce the ammonia content of the medium decreased in both adhesion and suspension cultures, though to different extents. In suspension cultures, ammonia content was reduced from 350 microM to about 100 microM (day 4) and to about 180 microM (day 6). No significant reduction was seen on day 8 of culture. In contrast, hepatocytes attached to collagen coated dishes remained viable and functional for at least 8 days after plating, reducing ammonia content from 350 microM to 70 microM (day 4), 90 microM (day 6) and 180 microM (day 8). The period of useful metabolism of hepatocytes in bioreactors for hybrid liver support systems appears to depend on the culture conditions.

Isoelastic polyurethane prosthesis for segmental trachea replacement in beagle dogs.

Porous polyurethane (nonwoven) was used for the development of tracheal prosthesis, which--in a special testing design--was adapted to shape and biomechanic properties of the natural organ. This prosthesis was implanted into 19 beagle dogs using inverted, everted, and end-to-end anastomosis. Insufficiency of the anastomosis or infection was observed in the everted and end-to-end anastomosis, whereas the inverted anastomosis showed complete incorporation into surrounding tissue of the porous prosthesis but was complicated by airway obstruction due to anastomosis granuloma.

Endothelial cell seeding on different polyurethanes.

Six polyurethanes (PUs) were tested with respect to their cytocompatibility. Initial adhesion, initial spreading, and the proliferation of endothelial cells were investigated. All smooth PUs showed similar initial adhesion. Initial spreading was faster on rough PUs. Collagen coating resulted in faster initial adhesion but not better proliferation of endothelial cells.

Endothelial cell seeding on PTFE vascular prostheses using a standardized seeding technique.

A standardized method was developed for seeding endothelial cells (EC) in tubular vascular grafts. A rotational cell seeding device for tubular prostheses is presented and parameters influencing the kinetics of cell adhesion (rotation speed, graft diameter, cell suspension level, inoculated cell number) are reported. Seeding EC in 14 mm ID PTFE vascular grafts with rotation rate of 10 rph gave an adhesion rate of 80% in a homogeneous monolayer.

[Free microvascular rib transplant]. / Das freie mikrovaskuläre Rippentransplantat.

The transfer of a free ventral and dorsal rib graft by microvascular anastomoses enables the plastic surgeon to effect bony reconstruction if the recipient site is defective. However, since this is a technically complicated procedure and associated with only partial recovery, this type of bone graft can be employed only in selected problem cases.

Dynamic model for the development and testing of a tracheal prosthesis under preclinical conditions.

The development of a tracheal prosthesis was evaluated using in vivo data on mechanical loads in the natural organ. The application of in vivo loads to the explanted organ in a laboratory tester was shown to give information on the natural reaction forces of the organ. It is therefore possible to perform in vitro tests on various prosthesis prototypes under near-natural stress conditions and to adapt the prostheses accordingly before implantation.

Cell seeding on microporous and solid polyurethane.

Cell coating with human embryonal fibroblasts was examined on solid (Plathurane UM 8300) and microporous (Tecoflex 80 A) polyurethane. Using measurements of cellular growth kinetics and adhesion strength it was found that the onset of cellular growth on the microporous material was delayed but that the vitality and adhesion strength of the cells were better than for the solid material.

A new bioprosthesis: impermeable for bacteria, permeable for fluids, incorporable by connective tissue.

Polyurethane non woven membranes with microporous inner layer and macroporous outer layer where tested bacteriologically and histologically. It was proved that the macroporous layer is suitable for the ingrowth and maturing of connective tissue, while the microporous structure prevents the invasion of bacteria, nevertheless being permeable for nutrient substances. So the material could be yield favourable presupposition to achieve bioincorporation in contaminated borderlines.

Evaluation of trachea kinetics in men and beagle dogs as a basic information for prosthesis construction.

Morphometric investigations on trachea kinetics in man and beagle dogs were undertaken to find out the range of motility in different moving planes. The results show a special mechanism of load distribution over the whole organ during movement. The minimal and the mean values for bending and torsion were recorded and made reproducible for to examine a trachea prosthesis in laboratory tester on its suitability for organ replacement.

[Biomechanical problems in elbow joint dislocations with coronoid and capitulum radii fractures (author's transl)]. / Biomechanische Probleme bei Ellenbogenluxationen mit Frakturen am Processus coronoideus und Radiusköpfchen.

Dorsal dislocation occurs in 80% of all fracture dislocations of the elbow joint. In 10-15% of these njuries the coronoid process and the radial head are involved. If this injury causes the defect of the radial head - which means the loss of the main supporting part of the joint, - it is only the coronoid process which gives stability to the elbow joint. Therefore, in cases of coronoid fracture it is of utmost importance to reconstruct the coronoid process, if the fracture involves more than 1/6 of the incisura olecrani. Advisable for fixation is the use of a lag screw. In some cases the reconstruction with autogenous bone graft or osteotomy of the olecranon is indicated.