Biomedical subjects

R Schnettler

Publications and source records attributed to R Schnettler.

At least 19 recordsLinked to original sources

PubMed2007

[Intraoperative radiation exposure in elastic stable intramedullary nailing (ESIN) during the growth period. Observations in 162 long bone shaft fractures].

BACKGROUND: The increase of intraoperative radiation exposure in intramedullary techniques of osteosynthesis is recognised and accepted in adults especially in interlocked nailing. In contrast data about fluoroscopy times in elastic stable intramedullary nailing (ESIN) in children and adolescents are hardly available. MATERIAL AND METHOD: Operation records of 162 surgical procedures (8.6% humerus, 43.8% forearm, 32.7% femur, 14.8% lower leg) of a 3-year period were evaluated retrospectively. The mean age was 6.1 years in femoral shaft fractures, nearly similar in forearm and lower leg fractures (8.7 and 7.9 years, respectively) and 12.4 years in patients with humeral shaft fractures. RESULTS: Mean operation (OP) and fluoroscopy times (FL) were increased in humeral fractures (58.1 min OP, 1.62 min FL), at a medium level in forearm fractures (35.2 min OP, 1.06 min FL) and femoral fractures (42.3 min OP, 1.27 min FL) and shortest in lower leg fractures (29.6 min OP, 0.69 min FL). CONCLUSION: Our results and literature analysis show that optimal technical conditions, especially the use of a pulsed image intensifier and well-trained theatre staff, are able to reduce intraoperative radiation load.

Body Burden↗

PubMed2006

[Distraction osteogenesis for adjusting humeral length difference due to premature closure of the proximal growth plate in a simple bone cyst].

Complications after pathological fractures of simple bone cysts of the humerus are refracture, cyst recurrence, and in rare cases premature closure of the physeal plate with resulting shortening of the arm. Length discrepancies of the lower limbs beyond physiological limits need early compensation in children as well as adults to avoid interference with the pelvis and spine. However, surgical treatment of length differences of the humerus is usually cosmetic, because even considerable discrepancies do not lead to functional deficits. We report the long-term course of a complicated bone cyst of the proximal humerus and resolving a severe length difference of 7 cm by distraction osteogenesis in a young adult. The cause of the premature physeal closure and the primary therapeutical concept are discussed.

Adolescent↗

PubMed2006

[Cost-benefit analysis of the use of rhBMP-2 in open tibial fractures: savings from a health insurer's perspective].

BACKGROUND AND PURPOSE: The purpose of the current study was to evaluate savings from the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in open tibia fractures by faster fracture healing and reduction of secondary treatment costs from a health insurance perspective for Germany and to compare them to the upfront price of 2900 EUR of rhBMP-2. METHODS: Raw data from a previously published study (BESTT study) were used to conduct an economic calculation for secondary treatment costs for each patient from the standard care group and the 1.5 mg/ml rhBMP-2 group based on G-DRG 2005 prices from a health insurer's perspective for an observation period of 1 year for Germany. RESULTS: The use of rhBMP-2 leads to savings of 5697 EUR and 3183 EUR per patient for Gustilo-Anderson grade IIIB and all grade IIIA and B injuries, respectively. These savings offset the upfront price of 2900 EUR of rhBMP-2 and, therefore, net savings of 2797 EUR and 283 EUR for grade IIIB and all grade IIIA and B injuries can be achieved, respectively. These savings are mainly due to reduced sickness payments because of faster fracture healing in the rhBMP-2 group. CONCLUSIONS: The current study shows that the use of rhBMP-2 in Gustilo-Anderson grade IIIA and B open fractures leads--besides the better medical outcome for patients as shown previously in the BESTT study--to net savings from a health insurer's perspective.

Bone Morphogenetic Protein 2↗

PubMed2006

[School accidents--an epidemiological assessment of injury types and treatment effort].

Children and adolescents spend up to 50% of their time at school. The purpose of this study was to assess injury patterns with their treatment of school accidents in a Trauma Service of a German University Hospital and to compare these data to the literature. All school accidents from 01.07.1999 to 30.06.2004 were statistically analysed in a retrospective manner by chart review. There were 1399 school accidents treated in our department. Average age of the injured children was 11.8 years with a boy:girl ratio of 3:2. Almost 40% of the injuries occurred during school sport. The most frequently injured region was the upper extremity including the hand (36.8%). Distortion and contusion were the most frequent diagnoses of all injuries. 16% of the cases had to be treated surgically and/or under general anaesthesia and also a total of 16% of the patients had to be admitted to the hospital. It can be concluded for school facilities that special attention has to be paid during school sports activity and breaks because they account for most accidents. Traffic education may reduce severe injuries. For diagnosis and treatment of school accidents specific knowledge of the growing longbones of the upper extremity and the hand is important.

Accidents↗

PubMed2006

Posteromedial approach to proximal tibia for corticotomy in callus distractions.

Corticotomy of the tibia using Ilizarov's anterolateral approach is used routinely for callus distraction. This method is associated with impaired callus formation and delayed healing because of marginal soft tissue covering and blood supply to the proximal tibia. We presumed a newly designed posteromedial approach would result in less callus defects and improved healing. In this prospective, randomized study, 31 patients had callus distraction using an anterolateral approach or the newly designed posteromedial approach. Callus formation was assessed radiographically and histologically. Callus defects were classified using serial radiographs. Biopsy specimens were taken from high-grade defect (Grades 3-4) zones to examine the osteogenic potential. Radiographic evaluation showed 13 callus defects; 12 occurred after the anterolateral approach and only one occurred after the posteromedial method. Although low-grade defects (Grades 1-2) healed spontaneously, biopsy specimens taken from Grades 3-4 defects revealed no osteogenic potential and requiring operative revision. Because of low soft tissue covering and impaired blood supply to the anterior tibia during surgical exposure for corticotomy, less callus formation occurred after the anterolateral approach compared with the posteromedial approach. We recommend the less invasive posteromedial approach to reduce callus defects and impaired healing in callus distraction of the proximal tibia.

Adolescent↗

PubMed2005

Regulation of mesenchymal stem cell and chondrocyte differentiation by MIA.

Melanoma inhibitory activity (MIA), also referred to as cartilage-derived retinoic acid-sensitive protein (CD-RAP), an 11-kDa secreted protein, is mainly expressed in cartilaginous tissue during embryogenesis and adulthood. Currently, the function of MIA in cartilage tissue is not understood. Here, we describe that MIA acts as a chemotactic factor on the mesenchymal stem cell line C3H10T1/2, stimulating cell migration significantly at concentrations from 0.24 to 240 ng/ml, while inhibiting cell migration at higher doses of 2.4 microg/ml. When analyzing the role of MIA during differentiation processes, we show that MIA by itself is not capable to induce the differentiation of murine or human mesenchymal stem cells. However, MIA influences the action of bone morphogenetic protein (BMP)-2 and transforming growth factor (TGF)-beta 3 during mesenchymal stem cell differentiation, supporting the chondrogenic phenotype while inhibiting osteogenic differentiation. Quantitative RT-PCR analysis revealed the up-regulation of the cartilage markers MIA, collagen type II and aggrecan in human mesenchymal stem cell (HMSC) cultures differentiated in the presence of MIA and TGF-beta 3 or BMP-2 when compared to HMSC cultures differentiated in the presence of TGF-beta 3 or BMP-2 alone. Further, MIA down-regulates gene expression of osteopontin and osteocalcin in BMP-2 treated HMSC cultures inhibiting the osteogenic potential of BMP-2. In the case of human primary chondrocytes MIA stimulates extracellular matrix deposition, increasing the glycosaminoglycan content. Therefore, we postulate that MIA is an important regulator during chondrogenic differentiation and maintenance of cartilage.

Adult↗

PubMed2005

The arteries of the humeral head and their relevance in fracture treatment.

Bone vascularisation has gained increased interest in relation to the blood supply of bone fragments during treatment of fractures. In the current study the pattern of vascular supply of the proximal humerus was studied in six cadavers by the corrosion technique. Furthermore, the effect of fractures on the vascular supply was also investigated. In all preparations the intraosseous arteries of the humeral head arose from the circumflex arteries, which surrounded the humerus and dispatched branches towards the proximal end. The main vessel was the branch of the anterior circumflex artery, penetrating the major tubercle in six of six cases. Due to the intraosseous arch shape of this vessel it is referred to as the arcuate artery. Besides other smaller vessels, there was also a vascular network arising from the posterior circumflex artery. Their branches penetrated medially at the cartilage bone interface in five of six preparations. The medial bone arteries appear to gain distinctive importance in humeral head fractures by their impact on the vascularisation of the fracture fragments. After disruption of the arterial supply from the arcuate artery, the vascularisation of the head fragments is most likely ensured by this group of vessels. Therefore, necessary repositioning manoeuvres during open reduction of the fracture should be conducted with care in order to preserve these arteries.

Aged↗

PubMed2005

[Allocating and scheduling operating room time].

During the past decade many scientific advances have been made concerning the development of methodologies to maximize efficiency of surgical facilities through allocating and scheduling of operating rooms. In this article such a methodology is described. Using the analysis of historical data of surgical activity in a facility, future demand is predicted and planned. Part of the methodology includes principles and rules needed for the daily organization and operative management of surgical facilities. They are also derived from the same science and therefore the basis for rational and structured decision making. Medical aspects such as patient safety and free choice of day for surgery have higher priority than the economic goal of maximizing operating room efficiency.

Efficiency, Organizational↗

PubMed2005

[Dislocation of artificial cartilage (SaluCartialge)].

Treament of focal cartilage defects is challenging, and techniques of bone marrow stimulation or cartilage transplantation are not sufficient to reconstitute hyaline cartilage. Preliminary results of artificial cartilage repair are promising, but no long-term results are available. Here, we report on a case of graft dislocation 6 months after artificial cartilage repair (SaluCartilage). We conclude that this method is not fully developed and more long-term results are required.

Arthroplasty, Replacement, Knee↗

PubMed2005

[Bioresorbable bone adhesives. Historical perspective and current status].

Bone adhesives are degraded to non-toxic products and resorbed after fulfilling their function in contact with living tissue. There has been a growing interest in the use of such adhesives in all fields of medicine in recent years. The wish of trauma surgeons and orthopaedic for alternatives to osteosynthesis is reflected in the development of a variety of surrogates of biological or synthetic origin. Despite a longstanding history of research in this field, a clinically applicable alternative in the field of bone gluing has not yet been found. This application has consistently failed because these adhesives were not tailored to the conditions met within the living organism. The following article is meant to provide an overview of the development, the state of the art, and today's knowledge of bone adhesives. In addition, it points out the tremendous progress in this area, made possible by the joint efforts of basic researchers and surgeons. The results of this collaboration show that in the future a successful reconstructive surgery using synthetic biomaterials will become feasible.

Absorbable Implants↗

PubMed2005

[Reaming debris: a source of vital cells! First results of human specimens].

Reaming debris is generated in the course of intramedullary reaming of long bones. Up to now there has been little information about the composition of reaming debris. Especially, it remains to be elucidated if reaming debris contains vital cells. The goal of the present vitro investigation has been the harvest of cells from human reaming debris and the subsequent characterization of the cells. 21 specimens of human reaming debris have been investigated. Each specimen has been divided into two parts. One part has been examined by means of transmission electron microscopy while the other part of each specimen has been transferred into culture dishes. The developing cell cultures were characterized by using FACS analysis and were incubated within osteogenic, adipogenic and chondrogenic differentiation media. The results of electron microscopy have revealed the presence of both, vital cells and massively altered cells. Cell growth occurred after initial plating of all specimens. The cells which were grown within the culture dishes could be characterized as mesenchymal stem cells on the basis of their morphology, differentiation capacity and antigen profile. Based upon these results reaming debris has to be regarded as a source of vital mesenchymal stem cells. It remains to be elucidated, if reaming debris can be used as an alternative to bone tissue grafting.

Bone Transplantation↗

PubMed2005

[Frequency and severity of callus defects. Dorsomedial vs ventrolateral approach for corticotomy in performing callus distraction of the tibia].

BACKGROUND: The purpose of this study was to compare a dorsomedial to the ventrolateral approach for corticotomy in performing callus distraction of the proximal metaphyseal tibia. PATIENTS AND METHODS: A total of 31 callus distractions were performed in 28 humans. The ventrolateral approach was used for 18 and the dorsomedial approach for 13 corticotomies. A scale of four severity grades was used to classify callus defect zones based on their extent as evidenced on serial X-rays. Biopsies were taken from higher-grade defects (grades 3-4). RESULTS: A total of 13 radiological evaluations revealed 12 defects using the ventrolateral approach. Seven defects (grades 1-2) healed spontaneously, whereas six defects (grades 3-4) required operative intervention as histological tissue examination showed no osteogenic potential. CONCLUSION: To prevent callus defects of the proximal tibia in the future and to ensure maximal osteogenic potential in the distraction zone, a minimally invasive dorsomedial approach appears to achieve favorable results.

Adolescent↗

PubMed2005

Plasma transglutaminase factor XIII induces microvessel ingrowth into biodegradable hydroxyapatite implants in rats.

Coagulation factor XIII is a member of the transglutaminase-family. Transgluaminases cross-link either fibrin monomers in blood coagulation or extracellular proteins in extracellular matrix formation. In early stages of bone healing migration and proliferation of endothelial cells lead to formation of new vessels. The aim of this study was to investigate the angiogenetic activity of plasma factor XIII in bone defects filled with nanoparticulate hydroxyapatite paste. A critical size defect was created in the tibial head of rats which was not filled in group I. In group II the defect was filled with hydroxyapatite paste, and in group III with hydroxyapatite paste enriched with factor XIII. Ten days after surgery angiogenesis in the defects was assessed using immunohistochemistry and confocal laser scanning microscopy. Ac16 antibody was used to detect activation of factor XIII into factor XIIIA. In defects without biomaterial (group I) vessel-rich connective tissue and diffuse distribution of capillaries was observed. In defects filled with pure hydroxyapatite (group II) formation of capillaries was limited to the host bone-hydroxyapatite interface. In contrast, addition of plasma factor XIII to hydroxyapatite (group III) stimulated formation of vessels within the biomaterial. The current study reveals that factor XIII can improve angiogenesis in hydroxyapatite.

Absorbable Implants↗

PubMed2005

[Covering of soft tissue defects of the lower leg with adipo-facial flaps].

AIM OF THE STUDY: Soft tissue covering on the lower leg is a difficult challenge. A plastic surgical method for covering of these soft tissue defects is presented. PATIENTS AND METHODS: From May 1997 until May 2003 36 patients were treated using neurovascular flaps. Above the sural or the saphenous nerve an adipo-facial flap is dissected, rotated into the defect and fixed without tension. Wound closure of the donor-site defect is done primarily or by mesh-graft. RESULTS: In 35 cases the flap healed without functional impairment. Primary healing was achieved in 30 patients. In 5 cases partial loss of the skin island was registered, whereby subcutaneous tissue remained vital. Revision by mesh-graft transplantation led to successful healing in these patients. In only one patient necrosis of the flap was seen. CONCLUSION: Neurovascular flaps usually result in reliable and complete healing of soft tissue defects of the lower extremity.

Adolescent↗

PubMed2005

[Fractures of the scaphoid tubercle].

BACKGROUND: Avulsion fractures of the scaphoid tubercle (Herbert type A1) are rare. Recommendations in the literature focus on a four to six week plaster immobilization including the thumb. Surgery is recommended in case of additional injuries to the carpus. MATERIAL AND METHODS: In a retrospective investigation including a 36 month period we reviewed acute fractures of the scaphoid and avulsion fractures of the scaphoid tubercle. RESULTS: We found 81 acute scaphoid fractures, four of them (4.9 %) were isolated tuberculum avulsions. Three cases were extra-, one case an intraarticular fracture. The first were treated conservatively, the last with a percutaneous screw. CONCLUSIONS: Following our own experiences with those rare injuries we recommend a differentiation of the fracture type into extraarticular injuries where conservative treatment should still be performed and intraarticular fractures where percutaneous screw osteosynthesis should be discussed.

Acute Disease↗

PubMed2005

[The arteries of the humerus and their relevance in fracture treatment].

BACKGROUND: The purpose of the current work was to study the arterial blood supply of the humerus to evaluate impairments of the blood supply after humeral fractures and different methods of fracture treatment. METHODS: Arterial blood supply of the humerus was studied by corrosion injection technique in 6 cadaver preparations and is compared with the existing literature. RESULTS: Humeral head arteries originate from the circumflex humeral arteries. The major vessel enters the greater tubercle. Another group of vessels accesses the head from medially. The nutrient artery for the shaft enters into the medial third of the shaft. At the distal humerus there are multiple anastomoses with penetrating branches into both condyles and proximal to the radial, coronoid, and olecranon fossae. CONCLUSIONS: Fragments of a proximal humeral fracture usually have an independent blood supply. The medial vessels to the head gain high importance in fractures of the anatomical neck. The nutrient artery lies regularly medial to the humeral mid-shaft and is at risk at open reduction of this region. The abundant vessels at the entire distal humerus ensure sufficient vascularization of the fragments after fracture.

Arteries↗

PubMed2005

Biochemical bone markers are useful to monitor fracture repair.

UNLABELLED: Biochemical bone markers reflect bone metabolism but little is known regarding their usefulness during fracture repair. Reduced bone mineral density may influence fracture healing. We hypothesized that low bone mineral density results in decreased levels of bone markers during the acute phase of fracture healing, especially in women who are postmenopausal. We also addressed the question of different fracture types and locations resulting in different levels of bone markers. Urinary levels of N-terminal cross-linked telopeptide, deoxypyridinoline, and pyridinoline were measured preoperatively and postoperatively in patients with hip fractures, distal forearm fractures, and in 25 control subjects. Bone mineral density was determined using quantitative computed tomography of the spine. Patients with low bone mineral density, especially women who were postmenopausal, had greater concentrations of N-terminal cross-linked telopeptide when compared with patients with normal bone mineral density or men. Patients with pertrochanteric fractures had greater concentrations than patients with femoral neck fractures, as did patients with hip fractures compared with patients with fractures of the distal forearm. These results suggest that levels of bone markers increase during fracture healing despite low bone mineral density and that different fracture types and locations result in different levels of bone markers. LEVEL OF EVIDENCE: Prognostic study, Level I (high quality prospective study-all patients were enrolled at the same time with > or = 80% of followup of enrolled patients). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗

PubMed2005

[Micro-CT analysis of cancellous bone fragments from the distal radius fracture zone in osteoporosis].

The incidence and prevalence of osteoporosis must be considered to continue to increase significantly due to the expected demographic development and environmental changes. In the diagnosis and staging of osteoporosis the three-dimensional bone structure should be as important as the bone mass or the mineral content of the bone. In this study, microfragments were taken from distal radius fracture zones and investigated in Micro-CT scans. Patients in which osteodensitometry of the lumbal spine had revealed osteoporosis in were found to have significantly reduced bone mass, bone density and trabecular thickness. Trabecular fractures which were found in non-osteoporotic patients even in robust trabeculae were detected by the two-dimensional analysis in thin locations and arborizations. Despite some trabeculae turned out to be very small the differences in the histomorphometry and the quality of trabecular fractures in osteoporotic as well as non-osteoporotic patients could be visualized very good in the Micro-CT analysis.

Absorptiometry, Photon↗