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Biomedical subjects

H Tscherne

Publications and source records attributed to H Tscherne.

At least 91 records · Page 5Linked to original sources

Management priorities in patients with polytrauma.

BACKGROUND: The basic principles for the treatment of the polytraumatized patient is early resuscitation, followed by a physical examination and diagnostic studies. These are performed to establish the priorities for life-saving management and further treatment. DISCUSSION: Trauma management regarding musculoskeletal injuries is discussed in four different distinguished periods: (1) acute or resuscitation period (0-3 h); (2) primary or stabilization period (3-72 h); (3) secondary or regeneration period (days 3-8); and (4) tertiary or rehabilitation period (beyond day 8). For management during the acute period, a trauma algorithm is described, which consists of four different steps: (1) first look; (2) shock treatment; (3) check up; and (4) control and diagnosis. During the acute period, decompression of organ cavities (tension pneumothorax, cardiac tamponade) is performed along with life-saving operations for hemorrhage control of thoracic, abdominal, pelvic or external bleeding. The primary period (3-72 h) of treatment starts when the vital functions have been stabilized. During this period, so-called 'day-one' surgery is performed. During the secondary period (days 3-8), a phase of regeneration, a secondary deterioration of organ function must be prevented. During the tertiary phase (beyond day 8), in most cases, recovery usually continues and final reconstructive operations can be performed.

Algorithms↗

Is early kinetic positioning beneficial for pulmonary function in multiple trauma patients?

Body positioning (kinetic therapy) is known to improve oxygenation in patients with impaired pulmonary function and ARDS. We have used body positioning prophylactically in trauma patients whose injury and pattern predispose to ARDS. This retrospective study reports the effects of early prophylactic (group P) versus late (group L) axial rotation on pulmonary function and the incidence of ARDS. Both groups were comparable in age, injury severity and the degree of thoracic injury. Systemic oxygenation was significantly better and the incidence of ARDS significantly lower in group P (group P: 34.3 per cent, group T: 74.1 per cent, P < 0.05). There was a tendency towards a lower incidence of pneumonia and a better survival in group P, which did not reach statistical significance. The duration of kinetic therapy and of ventilation was comparable in both groups. In this retrospective evaluation early prophylactic kinetic therapy was associated with a significantly lower incidence of ARDS compared with that instigated later.

Adult↗

CT-based analysis of the geometry of the distal femur.

When applying minimally invasive techniques (MIO, Minimally Invasive Osteosynthesis) to the fixation of the distal femur, the surgeon has access to a limited number of anatomical landmarks: namely the articular surface of the distal femur and a small portion of the distal lateral femoral cortex. A detailed knowledge of the local anatomy facilitates the technique and prevents complications. Using Kirschner wires placed at set positions in the distal femur, we analyzed the measurements obtained from the 3D reconstructed helical CT scans of 33 embalmed femora and we report on the anatomy of the distal femur as it relates to supracondylar fracture fixation.

Femur↗

Intraoperative control of axes, rotation and length in femoral and tibial fractures. Technical note.

In an effort to limit the amount of soft tissue dissection at the fracture site, indirect reduction and minimally invasive fixation techniques have been developed to treat femoral and tibial fractures. These techniques, which do not rely upon anatomical reduction of the fracture fragments, are technically difficult. Correct limb length, axial alignment in the frontal and sagittal plane, and rotation must be assessed using means other than open reduction. In this technical note, some simple and effective intraoperative clinical examination and radiographic techniques to determine limb alignment are described. These include: the 'cable techniques' for the determination of varus-valgus malalignment; the 'hypertension test', 'radiographic recurvatum sign', 'tibial plateau sign', and 'meterstick technique' for length analysis; and the 'hip rotation test', 'lesser trochanter shape sign', 'cortical step sign', and 'diameter difference sign' for rotational analysis. For each of the listed techniques, basic principles, technical instructions, limitations, advantages, and disadvantages are described.

Bone Malalignment↗

Management of calcaneal fractures in adults. Conservative versus operative treatment.

Significant progress had been made in the management of calcaneal fractures. This is reflected in the marked decrease in complication rates associated with the current intervention of these potentially devastating injuries. The treatment priorities that are key to achieve best results in a displaced calcaneal fracture are an anatomic reconstruction of the entire calcaneus including articular surfaces, height, alignment, and length, with a function directed postoperative management. The value of these priorities is confirmed by long term followup results. Conservative treatment should be considered only in cases of extraarticular fractures, in cases of minor displaced intraarticular fractures in patients who are nonambulatory, and in cases where there is a clear contraindication for surgery. An anatomic reconstruction of an os calcis fracture is difficult to obtain. In two-part fractures, according to the classification described by Sanders et al, an anatomic reduction is obtainable in more than 80% of cases. However, if the articular cartilage damage that is typically present is considered, a 70% rate of good to excellent clinical results is more realistic. In three-part fractures, anatomic reduction is attainable in approximately 60% of cases with a 70% rate of good results. These two subgroups comprise approximately 90% of all calcaneal fractures. It has been put into practice recently to optimize the extended lateral approach using posteromedial and anterolateral windows, so that an anatomic reduction can be achieved in more than 60% of os calcis fractures considered as Type III according to the classification described by Sanders et al. Additional scientific work in this area of trauma orthopaedics would benefit most from a general consensus on a fracture classification system and on a clinical scoring system, with 5-year followup studies using these treatment methods and evaluation systems.

Algorithms↗

Experimental study of distal interlocking of a solid tibial nail: radiation-independent distal aiming device (DAD) versus freehand technique (FHT).

OBJECTIVES: Recently, radiation-independent aiming devices for the tibia that compensate for insertion-related implant deformation have been developed, but the benefits of such systems have not been determined. This study prospectively evaluated the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement when using a radiation-independent distal aiming device (DAD) versus the freehand technique (FHT). MATERIALS AND METHODS: In an oblique cadaveric tibial fracture, a surgeon inexperienced in both techniques (DAD and FHT) performed statically locked intramedullary nailing. RESULTS: For the DAD and the FHT, respectively, the total operation time was 25.4 +/- 11.3 (mean +/- standard deviation) versus 30.9 +/- 14.3 minutes (p = 0.029), the distal locking time was 16.7 +/- 8.6 versus 21.9 +/- 10.5 minutes (p = 0.004), the total fluoroscopy time was 9 +/- 5 versus 93 +/- 34 seconds (p < 0.0001), the distal locking fluoroscopy time was zero versus 88 +/- 33 seconds (p < 0.0001), and the screw wear was -0.7 +/- 5.2 versus 26.8 +/- 31.6 micrometers (p = 0.001). The failure rate was 1.6 percent (one of sixty screws) in both groups. CONCLUSION: These results suggest that the DAD can eliminate the need for radiation during placement of distal interlocking screws.

Adult↗

Chest tube decompression of blunt chest injuries by physicians in the field: effectiveness and complications.

OBJECTIVE: Recent literature suggests that patients who undergo emergent tube thoracostomy in the field are at increased risks for complications. This study evaluates indications, complications, and effectiveness of field placement of chest tubes by an aeromedical service. METHODS: In a prospective study, 624 consecutive patients with chest injuries (Abbreviated Injury Scale score 1-6) were included. All patients were treated at the scene by a physician-staffed aeromedical service and transported by air to a Level I trauma center. Indications, clinical findings before and after chest tube insertion, and subsequent radiologic diagnosis by chest roentgenography were documented prospectively. RESULTS: Seventy-six chest tubes (50 unilateral, 13 bilateral) were inserted laterally in 63 patients (10%) by blunt dissection. Clinical findings included pneumothorax in 30 patients and hemothorax in 18 patients. In 15 patients receiving field chest tubes, neither pneumothorax nor hemothorax was confirmed. Six patients (<1%) arrived at the trauma center with unsuspected pneumothoraces and required chest tube insertion. No tension pneumothoraces escaped field detection and treatment. Four chest tubes placed in the field required repositioning in the hospital because of malfunction or malpositioning. Radiologic findings excluded intraparenchymal tube placements in all patients. No pleural infections were observed in these 63 patients during their hospital stay. No antibiotics were administered as a result of prehospital chest tube placement. CONCLUSION: Prehospital chest tube thoracostomy is safe, effective, and associated with low morbidity. Nontherapeutic chest tube placements occurred in 15 of 624 patients (2.4%); missed pneumothoraces occurred in 6 of 624 patients (<1%). Aggressive prehospital physician management of blunt chest trauma leads to an earlier treatment of potentially life-threatening injuries. Significant morbidity can be avoided by prompt pleural decompression using proper techniques.

Abbreviated Injury Scale↗

Prehospital airway management in the acutely injured patient: the role of surgical cricothyrotomy revisited.

BACKGROUND: Ensuring an unobstructed airway and adequate oxygenation are first priorities in the resuscitation of the trauma patient. In situations of difficult endotracheal intubation, rapid sequence protocols frequently include the use of paralytic agents and cricothyrotomy for airway management. Recent literature findings suggest that the prehospital use of cricothyrotomy is too frequent. The purpose of this study was (a) to evaluate the efficacy of a rapid sequence intubation protocol without the use of paralytic agents, and (b) to determine the need for cricothyrotomy by using this protocol in the field. METHODS: We prospectively analyzed 383 acutely injured patients who were in need of airway control. Success rates, indications, and complications of endotracheal intubation and cricothyrotomy were analyzed. RESULTS: Successful orotracheal intubation on the scene with the use of this protocol was performed in 373 of 383 patients (97%). Two patients (0.5%) arrived at the trauma center with unrecognized esophageal intubation. Eight patients underwent cricothyrotomy in the field, six without previous attempts at intubation. CONCLUSION: Experienced emergency medical services personnel can effectively perform endotracheal intubation with narcotic analgesics without the use of paralytic agents in the field. With proper training for field airway management, cricothyrotomy in the field can be reduced to a few indications with high success rates.

Adult↗

Coagulatory response after femoral instrumentation after severe trauma in sheep.

OBJECTIVE: Pulmonary complications after intramedullary femoral nailing have been attributed to bone marrow fat embolization and a variety of cascade effects. We investigated whether the coagulatory response after intramedullary femoral nailing in merino sheep is altered after severe trauma. METHODS: Adult merino sheep were submitted to hemorrhagic shock (2 hours, 50 mm Hg) and unilateral lung contusion. After recovery (day 3 of the study), reamed femoral intramedullary nailing (RFN), unreamed femoral intramedullary nailing (UFN), or plate osteosynthesis of the femur (P) was performed. Pulmonary artery pressure, central venous levels of factor V, protein C, antithrombin III, and fibrinogen, were determined. At 1 and 3 days before and after femur instrumentation, pulmonary capillary permeability was assessed on the basis of the comparative albumin content in bronchoalveolar lavage fluid. RESULTS: Group RFN, n=8; group UFN, n=7; group P, n=6. A significant (p < 0.05) postoperative increase in the relative albumin content in terms of the BAL/plasma albumin ratio was measured in group RFN (day 3 preoperatively: 0.38+/-0.05 day 3 postoperatively: 0.53+/-0.06, p < 0.05 (RFN vs. P), which contrasted with group UFN (day 3 preoperatively: 0.44+/-0.09, day 3 postoperatively: 0.46+/-0.09, no significant difference). This evidence of increased pulmonary permeability occurred in association with evidence of increased activation of coagulation factors (data presented as percentage of day 3 preoperative baseline values). The data for fibrinogen (15 min postoperatively) is as follows: group RFN, 74+/-9% (p < 0.05 vs. P); group UFN, 83+/-8% (not significant); group P, 98+/-6%. The data for antithrombin III (15 min. postoperatively) is as follows: group RFN, 72+/-6% (p < 0.05 vs. P); group UFN, 79+/-8% (not significant); group P, 92+/-8% (not significant). CONCLUSION: After severe trauma, an increase of pulmonary permeability after reamed femoral nailing was associated with increased consumption of coagulation factors. After unreamed nailing, a similar trend was apparent, but this was not found to be statistically significant. These data provide support for the theory that after severe trauma, unreamed femoral nailing reduces but does not abolish pulmonary sequelae when compared with reamed femoral nailing.

Adolescent↗

Internal fixation of multiple fractures in patients with polytrauma.

Within the last decade understanding of the pathogenetic consequences of trauma has been improved significantly. An additional reduction of lethality has been achieved that in part is related to increasing discrimination of complex injury patterns. Accordingly, additional staging in fracture management of these injuries has been developed. An overview of the current status of fracture management in polytrauma is given and certain regimens that are still controversially are discussed. The principles determined are based on the treatment experience of 4003 multiply injured patients within the past 23 years. The most important principles within the first hours after trauma represent adequate hemorrhage control. In fracture treatment the primary goal remains to perform primary stable osteosynthesis. In severe polytrauma with severe injuries to the extremities, the first decision is whether limb salvage can be achieved without risk of deterioration of the patient's condition. If this is the case, open fractures Grades III b and c usually can be stabilized primarily by unreamed intramedullary nailing or percutaneous plating. The priority pattern in multiple closed fractures is as follows: (1) tibia; (2) femur; (3) pelvis; (4) spine; and (5) upper extremity. Exceptions may ensue if severe head or thoracic trauma is present. Delayed treatment is performed for complex joint reconstruction, definitive treatment of maxillofacial injuries, and soft tissue reconstruction.

Algorithms↗

[The intestine as the central organ in the development of multiple organ failure after severe trauma--pathophysiology and therapeutic approaches].

Multiple organ failure is with an incidence of 10-25% and a mortality of 50-70% the most severe complication after severe trauma. Intestinal ischemia and a corresponding impaired gut barrier function is thought to have a high impact on the development of multiple organ failure after severe trauma. Under normal conditions the intestinal wall is a sufficient barrier against bacteria and their products. Gut ischemia is followed by mucosal lesions, the intestinal permeability is increased. Translocating bacteria and bacterial products (endotoxin, peptidoglykan) can lead to a local and/or systemic immun-inflammatory response, which is made responsible for the development of multiple organ failure. Tonometry as a possibility of monitoring intestinal ischemia as well as a tool to estimate the prognosis of multiple trauma patients is still discussed controversially. Dopexamin, which directly influences intestinal ischemia (goal directed therapy) might be a successful treatment option, however until now no clinical study about beneficial effects of dopexamine in severely injured patients is available. Selective gut decontamination showed no clinical benefits in multiple trauma patients. Early enteral nutrition especially with immunomodulating ingredients ("immunonutrition") decreases posttraumatic complications as well as the incidence of MOF. However a reduction of mortality could not be described in severely injured patients so far.

Bacterial Translocation↗

[Ventral interbody spondylodesis in injuries of the cervical spine. Indications, surgical technique and results].

Lower cervical spine injuries with instability of the anterior and/or posterior column can be treated by anterior interbody fusion and plate fixation. Plates available for anterior instrumentation of the lower cervical spine can be divided into locking or non-locking systems with uni- or bicortical screw purchase. Our biomechanical comparative testing of different screw fixation systems demonstrates improved stability with the use of bicortical purchase. Clinical studies, however, have proven high fusion rates without loss of correction and a low implant related morbidity with the use of unicortical as well of bicortical plate systems. Correct reduction and intraoperative positioning of the unstable cervical spine is crucial to avoid implant related complications. Also, limitations of anterior instrumentation for the treatment of specific lesions of the lower cervical spine have to be considered, e.g. in complex lesions with axial instability or in fracture dislocations with ankylosing spondylitis. Changes or alterations of adjacent segments can be reduced by the use of plates with correct lengths, contact of uninjured adjacent discs with implants should be avoided. A comparative analysis of two patient collectives--89 patients (1972-1983) and 102 patients (1987-1994), all of them treated with bicortical plate fixation--revealed different results in terms of implant failure, operative reduction and loss of correction. All but one surgical fusions had healed radiologically. Implant related complications during the first 3 months after the initial operation were lower in the latter group, only 3 out of 102 patients (3%) with implant loosening versus 7 our of 89 patients (8%) with implant breakage or loosening required surgical revision. In all cases technical errors could be detected. Clinical follow-ups with personal examination was performed in 144 patients: 57 of 72 survivors of series I (79%) after an average time of 11 years 9 months and 87 out of 94 survivors of series II (85%). The radiologic examination revealed 2 patients with screw breakage in series I, one patient with an asymptomatic implant loosening in series II. Only one case was observed with a loss of correction after loosened and early removed hardware. In all other patients there was no difference of radiologic angles between postoperative X-ray and follow-up. 16 patients, 12 of series I, 4 of series II, were fused in a kyphotic position after insufficient preoperative reduction. Radiologic alterations of adjacent segments, i.e. spondylophyts or "spontaneous" fusions, were observed in more than 50% of all patients of both series. However, complaints or persistent pain did not correlate with radiologic findings. Also in both series there was a high percentage of patients with mild, residual neck pain in spite of a very good radiologic result. Only in a very few cases the complaints had to be treated by drugs.

Adolescent↗

[Distal femoral fractures].

Techniques of operative treatment of supra- and intercondylar fractures have changed in recent years. These changes refer to reduction techniques and implant selection. Operative approach concepts, which remained unchanged for several decades were critically evaluated and modified to a minimal invasive osteosynthesis [MIO]. This included for intraarticular fractures a trans-articular joint reconstruction and a retrograde plate osteosynthesis (TARPO). This technique result in better operative visualization and management of intraarticular comminution, saver fracture healing and better functional outcome. For extraarticular fractures a minimally invasive percutaneous plate osteosynthesis (MIPPO) via stab incisions only or retrograde intramedullary nailing is available. Beside that new strategies and techniques for the avoidance of axial malalignment, rotational deformities and leg length discrepancies are described, as well as a new plate generation (LISS: less invasive stabilization system), which behaves more like an internal fixator. The complex nature of combined fractures and soft tissue injuries of the distal femur and proximal tibia needs special attention and specific management. Distal femoral and proximal tibial fractures in young patients are usually caused by a high energy trauma. They are complicated by a high rate of systemic and local injuries to cartilage, ligaments and skin. The patients in this group with severe injuries need a detailed treatment algorithm, because the surgeon's individual skill, enthusiasm and wishful thinking frequently led to unsatisfactory results. A decision making scheme is presented specifically addressing timing and treatment modalities.

Equipment Design↗

[Is modification of systemic inflammatory response syndrome and multiple organ failure by parenteral feeding possible?].

In this prospective, randomized, double-blind controlled clinical study, 29 patients after severe trauma (ISS about 40) were randomized to receive either IMPACT (Test) or an isonitrogenous isocaloric diet (Control). The primary study endopoints were the incidence of SIRS and MOF (definitions according to Bone, Goris and Sauaia). Test-fed patients developed significantly less SIRS between days 1 and 28 (8 vs 13.3, P < 0.05) and especially between days 8 and 14 (3 vs 6.2, P < 0.001). In the control group the Goris score was significantly worse (P < 0.05) on days 3, 4, 6, 7, 10, 11, 16, 17 and the Sauaia score on days 8, 9, 10, 11 (P < 0.05, P < 0.01). According to the results, an arginine, omega-3-fatty acids and nucleotide-enriched diet during early enteral feeding leads to reduction of SIRS and MOF scores after severe multiple injury.

Critical Care↗

[Definition of complex trauma and general management principles].

Complex joint trauma is a term reserved for specific and severe injuries that include two or more structural elements of the joint. These structural elements are the articulating bones, the major ligaments of the joint, the local soft tissue envelope and the neurovascular structures. Complex joint trauma has a high risk for complications and requires a special treatment algorhythm. A staged surgical protocol with initial soft tissue debridement, closed joint reduction and external fixation of the extremity followed by secondary reconstructive surgery after soft tissue recovery is suggested.

External Fixators↗

[A comparison of a fluoroscopy-free mechanical targeting system and a free-hand technic for the placement of distal interlocking screws of tibial nails].

Recently, radiation-independent aiming devices for the tibia which compensate for insertion-related implant deformation have been developed, but the benefits of such systems have not been determined. This study prospectively evaluated the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement with a radiation-independent distal aiming system and the free-hand technique. In an oblique cadaveric tibial fracture, a surgeon inexperienced with either technique performed a statically locked intramedullary nailing. For the aiming system and free-hand technique respectively, the total operation time was 25.4 +/- 11.3 vs 30.9 +/- 14.3 min (P = 0.029), the distal locking time was 16.7 +/- 8.6 vs 21.9 +/- 10.5 min (P = 0.004), the total fluoroscopy time was 9 +/- 5 vs 93 +/- 34 s (P < 0.0001), the distal locking fluoroscopy time was 0 versus 88 +/- 33 s (P < 0.0001), and the screw destruction was -0.7 +/- 5.2 vs 26.8 +/- 31.6 microns (P = 0.001). The failure rate was 1.6% (1 of 60 screws) in both groups. These results suggest that aiming devices can eliminate the need for radiation during distal interlocking screw placement.

Adult↗

[Complications of spongiosa harvesting of the ilial crest. A retrospective analysis of 1,191 cases].

We analyzed retrospectively 1191 cases of bone graft harvesting of the iliac crest which had been performed at our hospital between 1982 and 1991. There was an operative revision rate of 2.8%. For further study, we analyzed the clinical reports of all autograft (iliac crest) donors in a representative year (1991) and re-examined all those who still had symptoms. A total of 104 grafts were taken from 97 patients. Of these, 18 developed postoperative complications (19.6%), such as hematoma, which could usually be treated with local procedures such as aspiration. The rate of hematoma tended to be lower in those patients who had received a local coagulant, but this was not significant. Of the patients 55% still had problems 1 year after operation at the time of re-examination, but in most cases they were minor, for example, local irritation or discomfort. Serious problems developed in those patients who had a palpable defect of the iliac crest. We advise using local coagulants to decrease the rate of postoperative complications, although we cannot statistically prove the effect. When large grafts are harvested, the iliac crest should be reconstructed for better long-term results.

Adolescent↗