Search PubMed⌕ Search

Biomedical subjects

H Tscherne

Publications and source records attributed to H Tscherne.

At least 235 records · Page 13Linked to original sources
PubMed1992

The relationship of mechanical properties to morphology in patellar tendon autografts after posterior cruciate ligament replacement in sheep.

In a sheep model the posterior cruciate ligament (PCL) was replaced by a patellar tendon autograft (PTAG) using the central one-third of the ipsilateral patellar tendon (PT). The sheep were sacrificed at 16, 26, 52 and 104 weeks postoperation. The PTAG, and, as controls, the contralateral PCL and PT were harvested. These were examined using biomechanical testing as well as light and transmission electron microscopy, including immunohistological techniques. The material properties (maximum stress, elastic modulus) were compared to the morphological features. The cellular distribution, the distribution of glycosaminoglycans (GAGs), the collagen fibril diameter and the occurrence of Type III collagen were studied. Prior to transplantation, the PTAG was shown to be superior in maximum stress (57.2 +/- 5.5 MPa vs 41.3 +/- 1.9 MPa) and elastic modulus (368.8 +/- 49.3 MPa vs 172.3 +/- 14.6 MPa) to the PCL. The early decline in material properties of the PTAG (maximum stress 22% and elastic modulus 42% of the control) after free grafting paralleled a cell- and capillary-rich PTAG tissue with remnants of necrosis and a poorly organized extracellular matrix. Two years after implantation, with progressive alignment of the tissue matrix, maximum stress and elastic modulus acquired approximately 60 and 70% of the control, respectively. However, there was also an evidence of degenerative changes characterized by acellular areas, loss of the normal bundling pattern of collagen fibers and abnormal accumulation of GAGs. Ultrastructurally, there was a predominant shift to thin collagen fibrils in the PTAG compared to PCL and PT, both consisting of thick and thin collagen fibrils. Thin fibrils were demonstrated to be, in part, split thick fibrils as well as newly formed fibrils. Most of these thin fibrils revealed a positive reaction with antibodies to Type III collagen.

Animals↗
PubMed1992

Blunt abdominal trauma in cases of multiple trauma evaluated by ultrasonography: a prospective analysis of 291 patients.

Early recognition of blunt abdominal trauma in patients with multiple injuries and in shock is of utmost importance and calls for a rapid screening method. The reliability of diagnostic ultrasonography in detecting hemoperitoneum in patients with multiple trauma was evaluated prospectively. From 1986 to 1990, 291 patients with severe multiple injuries (ISS greater than 20, mean ISS 31.2) were included in the study. Laparotomy was performed on 117 patients (40%). Initial ultrasound (US) findings showed a sensitivity, specificity, and accuracy of 89%, 97%, and 94%, respectively, in detecting intra-abdominal injuries requiring surgical repair. The positive and negative predictive values were 94% and 95%, respectively. A standardized management of frequent repeat US studies can even improve on these numbers. In our department ultrasonography has replaced diagnostic peritoneal lavage (DPL) as the diagnostic study of first choice. Diagnostic peritoneal lavage is reserved for selected cases only.

Abdominal Injuries↗
PubMed1992

On-scene helicopter transport of patients with multiple injuries--comparison of a German and an American system.

Hospital-based helicopter services from a German (GER) and an American (AMR) university-affiliated trauma center were reviewed. All patients with multiple injuries transported via helicopter from the scene to the trauma centers during a 1-year period were included. The patients were comparable regarding mechanism of injury, age, flight times, mean ISS, ISS distribution, and number of severe injuries per body region (patients with AIS score > 3 for head, thorax, and abdomen). Overall mortality was 21 of 221 (9.5%) for GER and 21 of 186 (11.3%) for AMR (NS). Survivor-based TRISS analysis yielded Z statistics of +2.459 for GER (p < 0.025) and +1.049 for AMR (NS). M statistics were 0.89 for GER, 0.874 for AMR; the W statistic +1.35 for GER. There were nine unexpected survivors (Ps < 0.50) for GER and six for AMR. There was a significantly higher (p < 0.01) number of early deaths (< 6 hours) in AMR (12; ISS = 56) than in GER (four; ISS = 64). Analysis of the prehospital data demonstrated significant differences in the mean volume of IV fluids infused: 1800 mL, GER; 825 mL, AMR (p < 0.05); rate of intubation: 82 of 221 (37.1%) GER; 24 of 186 (13.4%) AMR (p < 0.001); and thoracic decompressions: 20 of 221 (9.1%) GER; 1 of 186 (0.5%) AMR (p < 0.001). Prehospital care in the GER system is directed on scene by a trauma surgeon member of the flight crew compared with a nurse/paramedic team with remote medical control in the AMR system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Pulmonary damage after intramedullary femoral nailing in traumatized sheep--is there an effect from different nailing methods?

Stabilization of femoral shaft fractures is a controversial issue in the management of patients with multiple trauma. Intramedullary nailing usually is preferred primarily; in recent years, however, pulmonary complications (e.g., ARDS) have been reported that were attributed to the reaming procedure. To study the effects of different nailing methods in a model of severe trauma, hemorrhagic shock and lung contusion were created at day 1 in sheep prepared by the method described by Staub. After recuperation (day 3) the animals in the study group (group 1) underwent intramedullary nailing of a closed femur without prior reaming; group 2 was treated with reaming and nailing according to AO standards. The reaming procedure led to an acute increase of pulmonary arterial pressure only in group 2 (19.8 +/- 2.1 to 31.0 +/- 4.6 mm Hg). Pulmonary triglyceride levels increased at parallel time points from 18.27 +/- 2.3 to 33.04 +/- 7.37 mg/dL only in group 2. Stimulatory capacity of polymorphonuclear leukocytes (PMNL) increased in the study group and decreased in controls (group 1: 2.652 +/- 0.23 x 10(6) cpm to 3.387 +/- 1.34 x 10(6) cpm; group 2: 2.699 +/- 0.34 x 10(6) cpm to 2.460 +/- 0.187 x 10(6) cpm). Intramedullary nailing caused an increase of lung capillary permeability in both groups; in the study group less damage was seen (group 1: 0.390 +/- 0.0006 to 0.354 +/- 0.011; group 2: 0.391 +/- 0.0004 to 0.336 +/- 0.015; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1992

The use of ultrasonography in the foot and ankle.

Ultrasonography of the soft tissue has achieved an increasing importance in the last years. Since sonography of the shoulder, knee, muscles, and tendons has become a routine method, there is less application of ultrasound in foot and ankle pathology. Since 1985, ultrasonography has been the routine examination technique in the Trauma Department of Hannover Medical School, Hannover, Germany. We now have a series of more than 4000 sonographic examinations. This paper gives a comprehensive overview of the possibilities in application and technique of ultrasonography in foot and ankle disorders. The sonographic patterns of the pathological changes of the main structures are described.

Ankle Joint↗
PubMed1992

[Effects of different intramedullary stabilizing procedures of the femur on lung function in polytrauma].

We investigated the effects of primary (< 24 h) intramedullary femoral nailing on lung function and pulmonary hemodynamics in multiple trauma patients. The standard procedure following reaming of the medullary canal (AFN) was compared with a new procedure using a small, solid nail without prior reaming (UFN). Pulmonary hemodynamics were determined using a pulmonary artery catheter. Global lung function was assessed by means of the oxygenation ratio (PaO2/FiO2). Concentrations of elastase and the platelet count as a general parameter of the clinical course were determined from central venous blood during and 3 days after surgery. The lung function was stable in UFN patients (n = 6), but decreased significantly in AFN patients (n = 10) from 353 +/- 24 (PaO2/FiO2 preoperative) to 260 +/- 28 (PaO2/FiO2 postoperative) and did not improve until 48 h later. Pulmonary artery pressure (Pap) remained within normal limits in UFN patients, whereas in AFN patients Pap increased from 27.4 +/- 3 mm Hg (preoperative) to 37 +/- 3 mm Hg during reaming and did not normalize until 1 h after insertion of the nail. The platelet count remained unchanged in UFN patients and dropped in AFN patients from 143 +/- 25 x 1000 cells/ml blood (preoperative) to 87.5 +/- 15 x 1000 cells/ml blood 2 days after surgery. Our measurements did not show an increase in central venous triglycerides in the AFN group, probably because bone marrow does not become immediately soluble. There was no significant difference between the increase of elactase levels in the two groups. The femoral nailing procedure with reaming in multiple trauma patients involves a potential risk to the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Osteosynthesis of distal radius fractures with biodegradable fracture rods. Results of two years follow-up].

Forty distal fractures of the radius were stabilized with biodegradable polyglycolic acid rods (Biofix). A forearm plaster cast was fit for 4 weeks. Nine patients developed late (4 to 16 weeks) aseptic inflammatory reactions at the pin site, which were treated by débridement. The histological specimens showed giant-cell phagocytosing fragmented polyermic debris. In two cases a bacterial wound infection occurred secondary to débridement. All local reactions healed within 4 weeks. A classification system and treatment regimen for these inflammatory reactions are proposed. Thirty-four patients (including those with local foreign body reaction) were available for the 2-year follow-up. The anatomical results of fracture reduction on the postoperative and follow-up radiograms were the same, confirming good mechanical fracture stabilization. According to the Sarmiento score, the overall results were excellent and good in 31 cases. In one of the three fair cases, the result was clearly due to the initial local foreign-body reaction. Because of the high incidence of local inflammatory reaction, for now clinical application of biodegradable implants seems problematic despite the good overall 2-year results. This should only be advocated for well-controlled prospective studies using implants with improved biocompatibility.

Adult↗
PubMed1992

[Can post-traumatic renal failure be modified therapeutically?].

Acute renal failure in the late phase after severe trauma is particularly dangerous, since it is resistant to therapy and contributes to the development of post-traumatic multiple organ failure. We have studied different treatment regimes in order to establish whether late renal failure can be prevented (study A: colloidal and crystalloid solutions; study B greater than: crystalloid solutions and dopamine; continuous infusion 3 micrograms/kg body weight). Renal function was assessed by means of the score by Goris as well as by creatinine clearance over a period of 14 days. Haemodynamics and cardiac function were determined on a daily basis. The demographic parameters were comparable in both groups. In group A 37 of 61 patients died (60.6%), and in group B 17 of 38 patients (44.7%) (P less than 0.05). The incidence of impairment of renal function was comparable; in group A there was significantly more severe damage (18%) compared to group B (2.6%). This coincided with significantly higher mortality in group A (group A: 60.65%; group B: 44.7%). In group A a lesser volume was given during the preclinical and clinical course, even after correcting for the volume-saving effect of colloidal solutions. In addition, cardiac index was higher in group B (day 9: 5.9 +/- 0.61 l/min) than in group A (day 9: 4.4 +/- 0.5 l/min) and pulmonary capillary wedge pressure (PCWP) was lower and systemic vascular resistance (SVR) higher over the whole period. Also, the arterio-venous oxygen difference (AvDO2) was higher following day 9 in patients in group A, but creatinine clearance was better in group B patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1992

[Standardized osteosynthesis techniques for the pelvic ring. Analysis of a patient sample and surgical technique].

A total of 1566 patients with fractures of the pelvis were treated at the Department of Traumatology at the Hannover Medical School between 1972 and 1990. Of these, 1350 patients had fractures of the pelvic ring, 216 isolated acetabulum fractures, and 398 combinations of pelvic ring fractures and acetabular involvement. Of these patients, 718 were admitted with severe polytrauma. For 1254 patients complete files were available for clinical and radiological evaluation of fracture distribution, classification (Tile and anatomical location) and concomitant injuries. A significant increase in the severity of trauma, the severity of the pelvic fractures and the rate of internal stabilization, especially of the posterior pelvic ring, was observed during the observation period. The overall mortality after pelvic fracture was 18.1%. This mortality was correlated to the Hannover Polytrauma Score (PTS) and the associated extrapelvic blunt trauma. Internal fixation of pelvic fractures was performed in 195 patients. Our experience led to standardized procedures for the different fracture locations. In fractures type Tile B, an anterior procedure led in all cases to anatomic or near anatomic healing. In unstable pelvic ring fractures (Tile C), external fixation led to a significantly higher rate of posterior dislocations (over 1 cm) than did internal fixation. In these situations a combined posterior and anterior internal fixation procedure improved the result compared to posterior internal stabilizations alone. As a result, internal stabilization using a standardized technique for every fracture location is recommended for all unstable pelvic ring fractures.

Adolescent↗
PubMed1992

[Primary management of pelvic injuries].

High energy fractures of the pelvis are often associated with genitourinary, neurological, vascular, intestinal, and other skeletal injuries. The pelvic fracture therefore reflects only some of the destructive energy sustained by the patient and is a marker for the associated soft tissue injuries. In these complex pelvic injuries assessment, stabilization, and definitive treatment are complicated. The mortality of complex pelvic injuries is high. Uncontrolled bleeding and septic complications are the main causes of death. The presence of the associated injuries necessitates thorough evaluation in every case. The goals of treatment are prevention of early death from hemorrhage, early detection and treatment of all concomitant injuries, and restoration of the patient to the preinjury level of function. At the scene of the accident, problems affecting the airway, breathing, and circulation should be dealt with first. For prehospital immobilization and transportation of the patient a beanbag should be used. With the aim of improving primary hospital treatment of patients with complex pelvic injuries, a trauma algorithm is presented. This provides for decisive therapeutic steps after brief clinical, radiologic and ultrasonographical assessments. The major questions in the flow chart take the pelvic ring and hemodynamic instability into account. Immediate laparotomy, surgical control of hemorrhage, and open reduction and internal fixation of an unstable pelvic ring are the most important requirements for successful treatment. From 1972 to 1990 the clinical course and outcome of 132 patients with complex pelvic injuries were reviewed. The overall mortality was 34.8%. As the changes in the treatment protocol were implemented mortality decreased from 66.7% (1972-1978) to 18.7% (1985-1990).

Adolescent↗
PubMed1992

[The problem of the sacrum fracture. Clinical analysis of 377 cases].

Sacral fractures are rare injuries that are often neglected because of the general severity of the patient's injuries. They are typical injuries in patients with polytraumata. A "hidden" injury, they are often diagnosed late or are even missed. In a well-documented consecutive series of 1,350 patients with pelvic fractures treated in the trauma department of the Hannover Medical School between 1972 and 1991, a total of 377 sacrum fractures were evaluated in a retrospective study. The cause of the accident, mechanism of injury, concomitant injuries, diagnostic procedures, classification of the pelvic injury (TILE), as well as the classification of the sacrum injury (DENIS), treatment and outcome were analyzed in all cases. Observed complications with special attention to injuries to the lumbosacral plexus were correlated with the classification of the sacrum and pelvis, as well as with a detailed analysis of the fracture pattern and fracture characteristics. In 89.4% at least one additional body region was injured in these patients. PTS (Hannover Polytrauma Score) groups III and IV included 42.5% of the patients. With an improved diagnostic protocol (radiological a.p. views, oblique views and CT scan), the observed rate of sacrum fractures was 33%. Neurological deficits occurred in 15.1% of the patients. In contrast to the literature, the rate of neurological deficits was related more to the degree of pelvic instability (TILE) than to the specific fracture pattern in the sacrum. In stable injuries (TILE A) neurological deficits were only seen in exceptions. In type B injuries the maximum rate was 10%, whereas in unstable fractures (TILE C) the rate of neurological deficits was 32.6% in transalar fractures (DENIS zone I), 42.9% in transforaminal fractures (DENIS zone II), and 63.6% in central fracture types (DENIS zone III). Additional risk indicators for neurological impairment are avulsion fractures of the sacrum, comminuted and bilateral fracture lines. The fracture classification should thus be modified. Our own experience with operative therapy for sacral fractures (open revision of the sacral plexus together with internal stabilization of the fracture) is still limited, but based on the experience presented, further development of the treatment protocol for sacrum fractures should be considered.

Adolescent↗
PubMed1992

[Comparative biomechanical studies of internal stabilization of trans-foraminal sacrum fractures].

A new method of internal stabilization of transforaminal sacrum fractures in unstable pelvic ring fractures was developed by modification of standard AO small-fragment implants. The rationale of this type of stabilization is the use of an unilateral dorsal approach and avoidance of transfixation of the uninvolved SI joints. In a comparative biomechanical study on 8 human cadaver pelvises two types of the new type of stabilization were compared to stabilization with Harrington sacral bars and transiliosacral screw fixation. The fracture model represented a Tile C1 type injury (symphysis disruption and transforaminal sacral osteotomy) on a complete pelvic ring. The anterior stabilization was performed with a 4-hole AO 4.5 mm DC plate in all cases. The load simulation used a one-leg standing model in an upright position with abductor muscle simulation. The pelvises were loaded in 4 load stages of 50%, 80%, 100% and 130% body weight. In each load stage 4 load-unload cycles were completed. With a three-dimensional measurement system (Polhemus 3 Space Motion Tracker) translations an rotations in the fracture plane could be analyzed. Typical behavior in the load-displacement curve was seen in all implants, with settling during the first cycles and permanent displacement after exceeding a specific failure load. The failure load showed no significant differences between implants (99.6-113.6% body weight). The analyses of the persistent displacement, the elasticity and the direction of displacement and rotation showed a typical behavior in the implants, but no differences, which can be interpreted as a significant difference in the stability of the fixation methods. In an additional test the new fixation method showed no loosening in 10,000 cycle loading with 60% body weight. The new stabilization method showed biomechanical results comparable to clinically successful methods of stabilization in the chosen fracture model. Thus, clinical applications of this type of stabilization may be successful.

Adult↗
PubMed1992

[Developments in the field of transplantation of bones and cartilage].

Experience with more than 2000 allogenic bone and cartilage transplantations between 1975 and 1990 confirms the indication for implanting this material in a wide range of applications. Especially in reconstructive surgery and after tumor resection the use of this procedure is increasing. The main advantage is the almost unlimited availability and the possibility of en bloc and orthotopic administration. Even with extensive defects, we saw satisfying results. An overall complication rate of 4.5% is low, and infection is the complication most frequently seen. Primary consolidation was seen in over 80% on average after 17 weeks.

Adult↗
PubMed1992

[15 years allogeneic bone transplantation. Indications, treatment and results].

Experience with more than 2000 allogeneic bone transplantations between 1975 and 1990 confirms that implantation of allogeneic, frozen preserved bone material has a wide range of applications. Use in reconstructive surgery and after tumor resection, in particular, is increasing. The main advantage of allogeneic bone transplantation is the almost unlimited availability and the possibility of en bloc and orthotopic administration. The primary application of allogeneic transplants for the treatment of multiply traumatized patients avoids the additional operative stress required for autogeneic harvesting. The composite graft is a special application with the advantages of both the high osteogenic potency of the autogeneic, and the unlimited availability of the allogeneic, bone material. Composite grafts have been used especially frequently for the treatment of pseudarthrosis and after tumor resection. Even with extensive defects we saw satisfying results. In the case of defects greater than 10 cm in length, however, pseudarthrosis developed in nearly 50%. An overall 4.5% complication rate after allogeneic bone transplantation is negligible, compared with other published results and with due consideration for the severity of the cases presented. Bone infection is the complication most frequently seen. In fracture treatment the complications result from the high rate of complex fractures (type C of the AO classification) and the nearly 20% accounted for by open fractures in our patient population. Transplantation is still a great challenge in pseudarthrosis and after tumor resection. The healing tendency after allogeneic bone transplantation is satisfactory; although more prolonged than with autogeneic material, consolidation is nearly the same after 30 weeks. Full weight-bearing is reached depending on the defect length at approximately 14 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Neoplasms↗
PubMed1992

[Classification and management of complex pelvic trauma].

Complex pelvic traumas are pelvic fractures accompanied by pelvic soft tissue injuries. Mortality in major pelvic fractures with associated soft tissue injuries is high, and these injuries can pose a more complex range of therapeutic problems. Uncontrolled bleeding and septic complications are the main causes of death. There has been extensive work on grading pelvic ring fractures, but less attention has been paid to grading the accompanying soft tissue damage. Therefore, a grading system for pelvic injuries was developed that takes the soft tissue damage into account more than the fracture classification did when used alone. It is a point system that considers the fracture itself, the soft tissue injuries, including lesions in the pelvic organs, vessels and nerves, and the general concomitant injuries. From 1972 to 1990 the clinical course and outcome of 132 patients with complex pelvic traumas were reviewed. The mortality was 34.8%. Eighty-three of the patients (62.9%) underwent immediate laparotomy and in 68 patients (51.7%) open reduction and internal fixation of the unstable pelvic ring were performed. For better primary treatment of patients with complex pelvic injuries, a trauma algorithm is introduced. It leads to important therapeutic steps after brief clinical, ultrasonic and radiological assessments. The major questions in the flow chart take the pelvic ring and hemodynamic instability into account. Immediate laparotomy, surgical control of hemorrhage, and open reduction and internal fixation of an unstable pelvic ring represent the most important requirements for successful treatment.

Adolescent↗
PubMed1992

[Determining indications and osteosynthesis techniques for the pelvic girdle].

1566 patients with fractures of the pelvis were treated at the Department of Traumatology of the Hannover Medical School between 1972 and 1990: 1350 patients had fractures of the pelvic ring, 216 isolated acetabulum fractures, 398 combinations of pelvic ring fractures and acetabular involvement; 718 of these patients were admitted with severe polytrauma. For 1254 patients a complete file was available for clinical and radiological evaluation of fracture distribution, classification (Tile and anatomical location) and concomitant injuries. During the observation period, significant increase in the severity of the trauma, the severity of the pelvic fractures and the rate of internal stabilization, especially of the posterior pelvic ring was observed. The overall mortality after pelvic fractures was 18.1%. This mortality depended significantly on the Hannover Polytrauma Score (PTS) and the associated pelvic and extrapelvic blunt trauma. Internal fixation of pelvic fractures was performed in 195 patients. This experience has now led to standardized procedures for the different fracture locations. With the task of minimizing soft tissue trauma and reducing the implant size, more differentiated treatment of sacral fractures is now applied. Adapted small fragment implants ("local osteosyntheses") can be applied, with an unilateral longitudinal dorsal incision providing an excellent overview over the fracture line. For internal fixation of sacral fractures, involvement (penetration by screws, transfixation) of the sacroiliac joint is avoided whenever possible. In our experience early open reduction and internal fixation of pelvic fractures facilitates the management of these severely injured patients.

Adolescent↗