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Biomedical subjects

H Tscherne

Publications and source records attributed to H Tscherne.

At least 19 recordsLinked to original sources
PubMed2002

Use of an injectable calcium phosphate bone cement in the treatment of tibial plateau fractures: a prospective study of twenty-six cases with twenty-month mean follow-up.

OBJECTIVE: To evaluate the potential benefit of a new injectable mineral bone cement (Norian SRS, Cupertino, CA, USA) for the treatment of tibial plateau fractures OTA types 41.B2-B3 and C3. DESIGN: Prospective study with established protocol. SETTING: University hospital; university teaching hospital. PATIENTS: Twenty-six patients gave informed consent to participate in this study and were available for follow-up examinations. All patients had sustained intraarticular tibial plateau fracture types OTA B2-B3 and C3. All cases were followed with a mean follow-up time of 19.7 months (6 to 36 months, median eighteen months). INTERVENTION: Twenty-five cases were treated with open reduction, osteosynthesis with screws or plate, and injection of Norian SRS in the subchondral bone defect. One case had closed reduction, screw osteosynthesis, and percutaneous cement injection. MAIN OUTCOME MEASUREMENTS: Radiographs in two planes were evaluated prospectively at six, twelve, and twenty-six weeks postoperatively and at last follow-up using Rasmussen's radiologic score. Clinical parameters were measured at the same time intervals using Lysholm's and Tegner's knee scores. RESULTS: Two cases required early wound revisions because of sterile drainage. Two cases developed partial loss of reduction of the fracture between four and eight weeks after surgery, requiring revision surgery in one case (total complication rate 15.3 percent). No other patients had complications, and all other fractures healed without any displacement. The high mechanical strength of the cement allowed early weight bearing after a mean postoperative period of 4.5 weeks (1 to 6 weeks). CONCLUSIONS: An injectable mineral bone cement with high initial mechanical strength was used to fill bone defects in unstable tibial plateau fractures with good success. This material offers new perspectives in the treatment of tibial plateau fractures.

Adult↗
PubMed2001

[Perthes syndrome. The classical symptom triad as a rarity in trauma surgery practice].

Perthes syndrome or traumatic asphyxia is a condition characterised by subconjunctival hemorrhage, cervicofacial petechiae and cyanosis caused by severe compression of the chest. Diagnosis is made by history and clinical examination. Associated injuries such as intrathoracic or abdominal lesions can be life-threatening and must be strictly assessed. This report demonstrates an illustrative case of this rare injury.

Abdominal Injuries↗
PubMed2001

[Pronation and supination of the forearm. With special reference to the humero-ulnar articulation].

The development of a kinematic model of the pro- and supination, that can be used to predict the influence of angulations of ulna and radius on the pronation and supination is based on the precise knowledge of the pronation and supination movement. We performed two parallel studies for examining the pronation and supination motion of the human forearm. The first experiment dealt with MRI-studies on 18 probands (36 examined forearms). As a result we observed an evasive movement of the ulna during the rotation of 7, 14 degrees medial. In order to prove whether the evasive movement was caused by a rotation of the humerus or by an evasion in the articulatio humeroulnaris, we carried out a second experiment, using 30 preparations. The measurement of the pro- and supination motion with a fixed humerus was expedited using a special experimental setup which guaranteed that the ulna could move freely. In all cases we found the same magnitude of the evasive motion of the ulna. Therefore we demonstrated, that the ulna performs an evasive motion during the pro- and supination motion of the forearm that influences the kinematic behavior of the pro- and supination motion significantly.

Adult↗
PubMed2001

[Current situation of traffic accidents in children and adolescents. A medical and technical analysis].

HYPOTHESIS: Analysis of the current injury situation in road users not exceeding 14 years of age involved in road traffic accidents to allow conclusions regarding future prophylaxis. METHODS: Traffic accident reports and medical records from children (< 15 years of age) were analyzed for the following parameters: Type, location and mechanism of injury, Abbreviated Injury Scale (AIS), Maximum AIS (MAIS), Injury Severity Score (ISS), Delta-v, collision speed, type and duration of treatment. RESULTS: In 12,309 traffic accidents occurring in the area of Hannover, Germany between 1985 and 1998, 7.5% (n = 2,317) of the involved persons and 10.5% (n = 1,734) of the injured road users were children and adolescents. 70% sustained MAIS 1 injuries, 28% MAIS 2-4 and 1.5% MAIS 5/6 injuries. The mean ISS was 3.38. 30.3% of the injured children were car occupants, 32.1% bicyclists, 33.3% pedestrians. 30.3% of the children were unrestrained car occupants, 42.1% used safety belts designed for adults, 36% used special devices. Half of the children in cars remained uninjured, whereas only 8% of the bicyclists and 2% of the pedestrians were not injured. Severe injuries occurred in 20% of bicyclists and pedestrians at a collision speed less than 30 km/h and in 80% at more than 50 km/h. Half of those crashes could have been avoided, if the colliding vehicle would had driven about 15 km/h slower. CONCLUSION: Children have an especially high risk of injury if they are involved in accidents as pedestrians, bicyclists and unrestrained car occupants. Besides of improvements of the inner and outer car design, the use of adjusted restraining systems and bicycle helmets is likely to prevent from severe injuries. Speed reduction is a considerable factor. According to our data, the injury severity for bicyclists and pedestrians increases progressively when the collision speed exceeds 50 km/h.

Accidents, Traffic↗
PubMed2001

[Hannover Fracture Scale '98--reevaluation and new prospects for an established score system].

UNLABELLED: The Hannover Fracture Scale (HFS) was first introduced in 1983. As the treatment of open fractures has improved over the years, mainly due to new implants, the prognosis of open fractures has also changed. Thus a reevaluation of this limb salvage score has become necessary. DESIGN: Retrospectively all parameters of the HFS were evaluated in 182 open fractures of the upper and lower extremity treated in our institution between June '94 and June '96. Statistical means included the multivariant analysis, ROC analysis, calculation of sensitivity, specify and accuracy for the criterion of primary amputation. Finally the HFS'98 was established, which is characterized by eight domains (bone loss, skin injury, muscle injury, wound contamination, neurology, periost stripping, local and systemic circulation), a total score range from 0-22 points and a cut off point (amputation recommended) at a score of > or = 11. This score was then prospectively applied on another 87 open long bone fractures, treated in our institution between July '96 and Dec. '97. RESULTS: This validation of the HFS'98 revealed a sensitivity of 0.82 and a specify of 0.99. In comparison the NISSSA and the MESS presented a sensitivity and specify of 0.71, 0.99 and 0.82, 0.99 respectively based on data of the prospective study group. In addition the Gustilo classification for open fractures has been defined by certain score ranges of the HFS'98. CONCLUSION: In conclusion the HFS'98 has become a reliable extremity salvage score with a fairly high positive predictive value of 0.99, which is applicable for all open long bone fractures regardless of their location.

Adolescent↗
PubMed2001

Hannover Fracture Scale '98--re-evaluation and new perspectives of an established extremity salvage score.

OBJECTIVE: as the treatment of open fractures has improved over the years, the prognosis of open fractures has also changed. Thus, a re-evaluation of the Hannover Fracture Score (HFS), first introduced in 1983, has become necessary. DESIGN: retrospectively all parameters of the HFS were evaluated in 182 open fractures of the upper and lower extremity treated in our institution between June 1994 and 1996. Statistical means included multivariant analysis, ROC analysis, calculation of sensitivity, specificity and accuracy. Finally the HFS 98 was established, which is characterised by eight domains with a total score range from 0 to 22 points and a cut off point (amputation recommended) at a score > or =11. This score was then prospectively applied on another 87 open long bone fractures, treated during July 1996 and December 1997. RESULTS: this validation of the HFS '98 revealed a sensitivity of 0.82 and a specificity of 0.99. In comparison the NISSSA and the MESS presented a lower sensitivity and same specificity based on the same study group. CONCLUSION: in conclusion the HFS '98 has become a reliable extremity salvage score with a fairly high positive predictive value of 0.99, which is applicable for all the open long bone fractures regardless of their location.

Adult↗
PubMed2001

Dehydroepiandrosterone decreases mortality rate and improves cellular immune function during polymicrobial sepsis.

OBJECTIVE: Sepsis is associated with a marked depression of cellular immune function. The steroid hormone dehydroepiandrosterone (DHEA) is proposed to have immunoenhancing activities. We, therefore, investigated the effect of DHEA on the mortality rate and cellular immune functions in an experimental model of sepsis. DESIGN: Randomized animal study. SETTING: Level I trauma center, university research laboratory. SUBJECTS: Male NMRI mice. INTERVENTIONS: Mice were subjected to laparotomy (sham) or cecal ligation and puncture (CLP). Mice were treated with (sham/DHEA; CLP/DHEA) or without (sham; CLP) the steroid hormone DHEA (30 mg/kg sc). Animals were killed 48 hrs after the onset of sepsis. MEASUREMENTS AND MAIN RESULTS: The survival rate of septic mice was determined 24 and 48 hrs after onset of sepsis. Forty-eight hours after the septic challenge, a white blood cell count was performed and serum tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta concentrations were monitored using ELISA. Furthermore, the delayed type of hypersensitivity (DTH) reaction was evaluated on the basis of ear pinna swelling after dinitrofluorobenzene (DNFB) administration, and clinical variables (body weight, temperature, heart rate, fluid input/output, food intake) were monitored using metabolic cages. DHEA administration improved the survival rate (87% vs. 53% after 48 hrs; p <.001). This was accompanied by a restoration of the depressed DTH reaction and a reduction in TNF-alpha serum concentrations (20.7 +/- 1.4 pg/mL vs. 32.4 +/- 6.6 pg/mL). CONCLUSIONS: These results demonstrate that DHEA administration leads to an increased survival following a septic challenge. The immunoenhancing effect of DHEA is accompanied by a reduction of TNF-alpha release and an improved activity of T-cellular immunity. DHEA administration may, therefore, be beneficial in systemic inflammation.

Adjuvants, Immunologic↗
PubMed2001

Foot fractures in restrained front seat car occupants: a long-term study over twenty-three years.

OBJECTIVES: To analyze the mechanism of injury for foot and ankle fractures resulting from automobile accidents to create a basis for developing an improved design for protection. DESIGN: Retrospective. SETTING: Level I trauma center with accident research unit. PATIENTS: Automobile accident reports and medical records of individuals injured in the accidents. MAIN OUTCOME MEASUREMENTS: Technical indicators (collision type, impulse angle, deltav, and extent of vehicle deformation) and clinical data (injury location and severity [abbreviated injury scale and injury severity score] and long-term outcome). RESULTS: From 1973 to 1996, 15,559 car accidents were analyzed. Two hundred sixty-one front seat occupants sustained fractures of the foot and ankle (ankle, 41 percent; forefoot, 29 percent; midfoot, 20 percent; and hindfoot, 10 percent). Seventy-five percent of the fractures were classified abbreviated injury scale(foot) 2. The incidence, location, and abbreviated injury scale(foot) category of fractures were similar between driver (n = 210) and front seat passenger (n = 51). Fifty percent of the fractures occurred in head-on collisions and 34 percent occurred in accidents with multiple collisions. The deltav ranged in 82 percent of car crashes between fifteen and sixty kilometers per hour. The deltav and extent of foot compartment deformation correlated with the abbreviated injury scale. During our investigation, deltav increased; the injury severity score decreased; and the extent of deformation did not differ significantly. CONCLUSIONS: Although overall car passenger safety has improved, the relative incidence of foot and ankle fractures has increased. Comparing drivers and front seat passengers, the foot pedals, steering wheel, or the asymmetric design of the dashboard did not influence injury incidence, mechanism, or severity. Foot fractures are mainly caused by the foot compartment deformation in head-on collisions, and therefore improvements in foot compartments are essential for fracture prevention.

Abbreviated Injury Scale↗
PubMed2000

[Acceleration related injury of the cervical spine in restrained car drivers. Frequency, causes and long-term results].

In an analysis of 3,838 restrained car drivers, the proportion of acceleration related injury of the cervical spine increased from under 10 % in 1985 to over 30 % in 1997. These injuries occurred mainly in the case of head-on or multiple collisions. Letters were sent to 1,136 of the injured persons, and of the 138 patients who returned the questionnaires, 121 (88 %) were still suffering from their symptoms. It was a question of pain (74 %), tension (6 %) and stiffness (5 %) in the head (27 %), neck (55 %) and shoulder (8 %) area. The duration of the complaints was the longest after multiple collisions. In addition to a slight influence of the accompanying injuries on the duration of complaints, the individual constitution seems to be an important determining factor. In order to resolve the difficulties of conducting of this retrospective study, prospective studies are necessary which include documentation of diagnosis, treatment protocols, duration and type of complaints.

Accidents, Traffic↗
PubMed2000

[Mechanism of pelvic girdle injuries in street traffic. Medical-technical accident analysis].

During 1985 and 1993, 7,410 persons were injured in traffic accidents in the area of Hanover. Of these, 306 (4.1%) sustained a pelvic girdle injury. In 139 cases (45%), the pelvic girdle injuries were further classified (Pennal and Tile) and a technical reconstruction of the accident situation was performed. 52% were type A, 27% type B and 21% type C injuries. Some 47% of the casualties were vehicle occupants, 31% pedestrians, 12% motorcyclists and 10% cyclists. In restrained vehicle occupants pelvic girdle injuries occurred mostly in accidents with a delta-v of more than 30 km/h, whereas in unrestrained vehicle occupants, pedestrians and cyclists they also occurred with lower delta-v or collision speed. The percentage of type B and C injuries increased with higher velocities. In addition to further improvements in passive safety, lower collision speed or delta-v is necessary to reduce or prevent pelvic girdle injuries. The reconstruction of pelvic girdle injury mechanism in traffic accidents is possible, when both technical and medical parameters are considered.

Acceleration↗
PubMed2000

[Fractures of the upper extremity in restrained automobile front seat passengers. Injury pattern and incidence in relation to accident mechanism].

During 1985 and 1995, 3,260 restrained car drivers (1,228 front seat passengers) were injured in 9,380 crashes involving cars. 179 (5.5%) (front seat passengers: 53, 4.3%) of those sustained fractures, of the arm. Among the 384 single fractures the hand (25%), wrist (23%) and forearm (23%) were affected most often, elbow (9%), upper arm (10%) and shoulder (10%) rather seldom. Half of the evaluated fractures of the long tubular bones were type A-fractures due to the AO classification and the other two quarters, respectively type B- and C-injuries in each case. 16% were open fractures. No considerable differences of the injury mechanism were found comparing drivers and front seat passengers. Since over half of all fractures resulted from a direct impact to the hand and/or arm, modifications are necessary in order to improve the energy absorption by means of padding the dashboard and the inner door. The use of side- and front-airbags could serve as an additional auxiliary equipment, as long as it doesn't induce a supplemental stress, through unfolding of the airbag.

Accidents, Traffic↗
PubMed2000

[Distal fractures of the femur].

Supracondylar femoral fractures still present a challenge to the treating surgeon. The incidence of delayed and non-unions is reduced due to the minimally invasive plating techniques, but establishing a correct axis and good function is still a problem. During the last few years new implants have been developed to allow less difficult operative techniques in minimally invasive surgery. The Less Invasive Stabilization System (LISS) is a percutaneous plating system with monocortical self-drilling screws. The screws are inserted with an aiming guide and form a stable angle with the plate. The distal femoral nail allows placement of a spiral blade in the nail, thereby enhancing the interlocking stability.

Adult↗
PubMed2000

[Post-traumatic osteolysis of the distal clavicle. A case report and review of the literature]].

The post-traumatic osteolysis of the distal clavicle is very infrequent and the etiology and pathology is poorly understood. It is important to consider this possibility for differential diagnosis when continued pain in the acromio-clavicular joint (AC joint) follows blunt shoulder trauma. The course of the disease may result in a 3 cm loss of length of the distal clavicle. Months and years may pass until osteolysis becomes manifest, but the earliest radiological findings are present 4 weeks after trauma. The disease is self-limiting and usually does not leave residues. We report a case of a 35-year-old man with a post-traumatic osteolysis of the distal clavicle after blunt shoulder trauma. The diagnosis was determined several months after pain persisted in his shoulder. Using this case we discuss the possible pathogenic mechanism, differential diagnosis and treatment options for the post-traumatic osteolysis of the distal clavicle.

Adult↗
PubMed2000

[Achilles tendon rupture].

The treatment of acute of Achilles tendon rupture experienced a dynamic development in the last ten years. Decisive for this development was the application of MRI and above all the ultrasonography in the diagnostics of the pathological changes and injuries of tendons. The question of rupture morphology as well as different courses of healing could be now evaluated objectively. These advances led consequently to new modalities in treatment concepts and rehabilitation protocols. The decisive input for improvements of the outcome results and particularly the shortening of the rehabilitation period came with introduction of the early functional treatment in contrast to immobilizing plaster treatment. In a prospective randomized study (1987-1989) at the Trauma Dept. of the Hannover Medical School could show no statistical differences comparing functional non-operative with functional operative therapy with a special therapy boot (Variostabil/Adidas). The crucial criteria for therapy selection results from the sonographically measured position of the tendon stumps in plantar flexion (20 degrees). With complete adaptation of the tendons' ends surgical treatment does not achieve better results than non-operative functional treatment in term of tendon healing and functional outcome. Regarding the current therapeutic standards each method has is advantages and disadvantages. Both, the operative and non-operative functional treatment enable a stable tendon healing with a low risk of re-rupture (1-2%). Meanwhile there is consensus for early functional after-treatment of the operated Achilles' tendons. There seems to be a trend towards non-operative functional treatment in cases of adequate sonographical findings, or to minimal invasive surgical techniques.

Achilles Tendon↗
PubMed2000

[Preoperative patient education. What is especially important?].

Any medical procedure must be legally authorized by the patient, giving informed consent. This prerequisite is based on the right to self determination. Otherwise a medical procedure is considered as physical injury. Thus, the way, how a specific procedure is performed, predominantly depends on the patient's will. The attending physician's duty is to find out this will, which is especially important when old patients and patients incapable of giving valid consent are involved. Before the procedure the physician has to have a confidential talk with the patient. He has to point out the best treatment possible considering the individual circumstances of the patient's life. The physician has to find out, weather the patient is competent to refuse or consent to treatment. Furthermore the consultation is an opportunity to diminish the patient's fear and to increase his confidence. The main problem treating old patients is that they often lack the mental ability for appreciation of the nature of the situation. One has to differentiate between the physiological mental decay and dementia or psychiatric diseases. In these cases a third party consent is necessary.

Aged↗
PubMed2000

Biomechanics of femoral interlocking nails.

Today there is a variety of different interlocking intramedullary nail designs available for the femur. We compared different nail types in the bone implant complex (BIC) of four unreamed solid nails and a slotted reamed nail with simulated comminuted mid shaft fractures to see if there are major differences in stiffness for axial load, bending and torsion. The fractures were simulated by a 2 cm defect osteotomy in paired human cadaver femora. Each bone was tested intact in a universal testing machine, osteotomy and osteosynthesis were performed, and the BIC was tested. Relative stiffness was calculated. In torque testing the unslotted solid nail showed significantly more stiffness (0.6-1.8 Nm/degrees) compared to the slotted nail (0.2 Nm/degrees). Compared to intact bone (6.9 Nm/degrees), both groups of nails were significantly less stiff (relative stiffness 2-20%). In axial load and bending testing the large diameter unreamed nail showed significantly higher stiffness (32-68%). This study shows that stiffness of bone implant complex in interlocking femoral nails is more dependent on nail profile than on the pressfit of nails in the medullary canal.

Adult↗