Search PubMed⌕ Search

Biomedical subjects

H Tscherne

Publications and source records attributed to H Tscherne.

At least 199 records · Page 11Linked to original sources
PubMed1995

[Various therapy concepts in severe fractures of the tibial pilon (type C injuries). A comparative study].

Between 1982 and 1992, 79 pylon fractures were treated with internal fixation as the primary treatment at the trauma department of the Hannover Medical School. In a retrospective study 71 patients were evaluated, and 51 of them were re-examined clinically and radiographically an average of 68 months after injury. The purpose of this study was to compare these different forms of surgical management concerning their long-term results: 1. Minimal invasive internal fixation for reconstruction of the joint with external transfixation of the ankle joint and/or plaster cast until bony healing occurred. 2. Primary internal fixation with plating of tibia and fibula following the AO techniques. 3. Internal fixation with a plate applied in a second step after initial reconstruction of the joint with minimal internal fixation and short-term external transfixation. Evaluation was based on the infection rate, the development of posttraumatic arthritis and the range of motion in the ankle joint as objective criteria. Subjective criteria were pain, swelling, and restrictions of working or leisure activities. Although only closed fractures were treated primarily by internal fixation with plating no significant differences between the three groups were found in the classification of fractures and soft tissue damage. All but 4 fractures were type-C lesions according to the AO classification, and 19 patients sustained open injuries. The infection rate for minimal invasive internal fixation was significantly lower with a two-step procedure (group 3) than with the one-step procedure according to a suitable statistic test (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Increased gut permeability after multiple trauma.

Gut permeability was studied in multiply injured patients with respect to the development of multiple organ failure (MOF). Two groups were defined according to MOF score (threshold 10 points) as to whether MOF developed (group 1; n = 11, four deaths) or did not (group 2; n = 21, no death). Gut permeability was determined from the ratio of urinary excretion of enterally administered lactulose and mannitol. Serum elastase concentrations were also determined. Mean(s.e.m.) gut permeability was abnormal during the entire study (day 1: group 1--5.1(2.1) versus group 2--10.6(4.1) (P not significant; P < 0.001 versus normal volunteers, 0.56(0.24)). An increase on days 3 and 5 correlated with serum elastase levels only in patients in group 1 (rs = 0.71, P < 0.01). Severe injury leads to increased intestinal permeability, which is related to a systemic inflammatory response.

Adult↗
PubMed1994

The effect of kinetic positioning on lung function and pulmonary haemodynamics in posttraumatic ARDS: a clinical study.

In the treatment of adult respiratory distress syndrome (ARDS) no breakthrough has been achieved so far. In several cases of severe ARDS in multiply injured patients we have seen improvements of lung function by means of continuous body positioning. We therefore compared the effect of kinetic positioning (KIN) on lung function and haemodynamics in ARDS patients with conventional (CON) supine positioning. Pulmonary and systemic haemodynamics were determined on the basis of pulmonary artery catheter measurements. On a daily basis oxygenation ratio (PaO2/FiO2) and pulmonary shunt (Os/Ot. per cent) were calculated. Extravascular lung water (EVLW, ml/kg BW) was determined by the double indicator thermodilution technique. Twenty-two patients were included: KIN, N = 11, CON, N = 11. Mortality from ARDS in KIN patients was 18.2 per cent (N = 2): in CON patients it was 63.6 per cent (N = 7). The oxygenation ratio (PaO2/FiO2) increased significantly in KIN patients from 140 + 45 (day 0) to 237 + 40 (P < 0.05) (day 5); in CON patients no improvement was seen (143 + 48 (day 0). 133 + 44 (day 5); n.s. between groups at day 0: P < 0.05 between groups at day 5). Pulmonary shunt decreased significantly from 26.6 + 4 per cent (day 0) to 12.5 + 2 per cent (day 5) (P < 0.05) in KIN patients and was 36.6 + 6 per cent at day 0 and 31.4 + 2 per cent at day 5 in CON patients (P < 0.05 between groups at day 5).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Does the reamer type influence the degree of lung dysfunction after femoral nailing following severe trauma? An animal study.

In multiple trauma patients with lung contusion, pulmonary complications have been reported that were attributed to intramedullary stabilization of the femur. The reaming procedure of the medullary canal is thought to play a major role. We investigated whether different types of reamers might exert different amounts of fat mobilization into the vascular system and different degrees of pulmonary dysfunction. Adult female Merino sheep were submitted to hemorrhagic shock (2 h, 50 mm Hg) and a unilateral lung contusion; in addition, a lung lymph fistula was created. Pulmonary capillary permeability, central venous triglyceride levels, 11-dehydro-thromboxane B2 (dh-TXB2) levels, and pulmonary artery pressure were determined. After recovery, animals were randomly assigned to intramedullary femoral nailing using several types of reamers: group A, AO reamer (n = 8); group B, Biomet reamer (n = 7); group H, Howmedica reamer (n = 6); group C, controls, no reaming (n = 4). Intramedullary reaming caused a significant (p < 0.05) increase in pulmonary artery pressure in groups A and B; dh-TXB2 levels increased in all groups. Statistically significant (p < 0.05) pulmonary capillary permeability damage was measured in group A only. Intramedullary femoral nailing can cause transient pulmonary hemodynamic and mediator effects as well as increased pulmonary capillary permeability. In the present study, this effect was evident in group A reamer systems only, which may be due to reamer construction.

Animals↗
PubMed1994

Posttraumatic multiple organ failure--a report on clinical and autopsy findings.

In a retrospective analysis, clinical data and histological specimens were obtained from patients (n = 59) who died of severe injury. Three groups with comparable injury severity were differentiated according to the time of death. In group A (death, within 24 h) (n = 15) despite multiple injuries, patients almost always died from brain injury. Pulmonary failure was the leading cause of death in group B (death, days 2-7) (n = 16). The majority of group C patients (death, > 7 days) (n = 28) died of multiple organ failure. Organ weights at autopsy were all pathologically high but did not show an association with the amount of intravenous volume infused during intensive care. Organ histology revealed signs of interstitial edema and infiltration of polymorphonuclear leukocytes in group B patients especially in the lung, and in all groups to a lower degree in liver and kidney. The distribution of interstitial edema and cell necrosis appeared to be organ-specific. Our data confirm the presence of a generalized inflammatory reaction in patients with severe trauma. The pattern of organ failure, in addition to known pathogenetic changes (mediators, endotoxemia, etc.), appears to be influenced by organ structure and perfusion.

Adult↗
PubMed1994

[Osteosynthesis of femur shaft fractures with the unreamed AO-femur nail. Surgical technique and initial clinical results standard lock fixation].

Nailing technique has changed in recent years in some important aspects which are not limited to the omitted reaming procedure. These changes concern patient positioning, reduction technique and determination of implant length and diameter. Approach and exposure techniques have been modified to new, less invasive procedures, in order to fulfill technical, functional and aesthetic requirements. Techniques and tricks have been developed for avoidance of fragment diastasis, axial and torsional malalignment and leg length differences. Finally, simple algorithms have been elaborated for the management of bilateral femoral shaft or ipsilateral tibial shaft fractures and the number and location of locking bolts. These algorithms, techniques and procedures were developed in a series of 108 femoral shafts, which were stabilized wit the AO unreamed femoral nail (UFN) in a prospective study between 1991 and 1994. Of these, 39 cases with a mean follow-up of 19.3 (range 8-40) months after trauma were reviewed. Fractures were classified according to Müller (1990): 6 type A, 21 type B and 12 type C. Closed soft tissue damage was classified according to our classification: C0/I, n = 14; CII, n = 15 (Tscherne 1982). Among 10 open fractures 4 were OI, 4OII, 1OIIIA and 1OIIIB (Gustilo 1976). The major complications were breakage of locking bolts (n = 2), one nail breakage after 9 weeks and one case of osteitis.

Adolescent↗
PubMed1994

[Current status of surgical technique for unreamed nailing of tibial shaft fractures with the UTN (unreamed tibia nail)].

Nailing technique has changed in recent years in some important aspects which are not limited to the omitted reaming procedure. These changes concern patient positioning, reduction technique, the use of temporary stabilizers such as the 'Pinless', and determination of implant length and diameter. Approach and exposure techniques have been modified to new, less invasive procedures, in order to fulfill technical, functional and aesthetic requirements. Techniques and tricks have been developed for avoidance of fragment diastasis and axial and torsional malalignment. Finally, simple algorithms are described for the management of large bone defects, bilateral tibia shaft or ipsilateral femoral shaft fractures, number and location of locking bolts, the 'when and how' of patient mobilization and load bearing, and primary and secondary dynamization. These algorithms, techniques and procedures were developed in a series of 152 tibia shafts, which were stabilized with the AO unreamed tibia nail (UTN) in a prospective study between March 1989 and June 1994. Of these, 75 cases with a mean follow-up of 19.4 +/- 6.3 (range 11-37) months after trauma were reviewed. Fractures were classified according to Müller (1990): 14 type A, 37 type B and 24 type C. Closed soft tissue damage was categorized according to our classification: C0/1, n = 5; C2, n = 12; C3, n = 9 (Tscherne 1982). Among 49 open fractures 8 were OI, 18 OII, 10 OIIIA and 13 OIIIB (Gustilo 1976). The main minor intraoperative complication was drill bit breakage (n = 10), most frequently at the proximal locking holes. The main postoperative complication was breakage of locking bolts (n = 16), mainly between weeks 6 and 20. Minor secondary reinterventions were, in most cases, secondary dynamization under local anaesthesia. Major reintervention were: soft tissue reconstructions (n = 5), isolated cancellous bone graft (n = 6), and change of treatment (n = 12). There were nine changes to a reamed nail, two changes, in very proximal fractures, to plate osteosyntheses. There were three deep infections. Mean time to union was 23.9 weeks (range 10-48 weeks, n = 73); in two cases non-union was observed. The overall result was judged with the Karlström-Olerud score, which was applicable in 66 of 75 cases; excellent, n = 2; good, n = 22; satisfactory, n = 24; fair, n = 9; poor, n = 9. In the remaining nine cases no scoring was attempted because of severe injuries around the knee or ankle.

Adolescent↗
PubMed1994

[Biomechanical studies of 9 tibial interlocking nails in a bone-implant unit].

Various different interlocking intramedullary nail designs are now available for the tibia the designs resulting from a different approaches to achieving stability for fracture fixation. During recent years small-diameter unreamed interlocking nails have been developed. So far there are no data on stiffness of different nail designs that can justify the use of certain nail types. We compared different nail types in the bone-implant complex (BIC) with reference to stiffness under axial load, bending and torsion of the BIC. We simulated comminuted mid-shaft fractures by a 2-cm defect osteotomy in paired human cadaver tibiae. We fixed each tibia with one of nine different interlocking nails (AO Unreamed Tibial Nail 9 mm [UTN9], AO Unreamed Tibial Nail 8 mm [UTN8], Russell & Taylor Delta Tibial Nail 9 mm [RTD], Russell & Taylor Reconstruction Tibial Nail 11 mm [RTR], Brooker & Wills Nail 11 mm [B-W], Grosse & Kempf Tibial Nail 11 mm [G-K], AO Universal Tibial Nail 11 mm [AOU], Klemm & Schellmann Tibial Nail 11 mm [K-S], Börner & Mattheck Tibial Nail 11 mm [B-M]) according to the manufacturers' recommendations. Each BIC was tested mechanically using a Zwick universal testing machine. Torque testing was performed with a maximum moment of 5 Nm in both directions. Maximum axial load was 1100 N. Four-point bending was done up to a moment of 66 Nm. For each implant bending and torque stiffness of the nail were calculated and compared with the test results obtained in the cadaver study. A P-value less than 0.05 (least significance difference test, ANOVA) was considered significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The Hannover experience in management of pelvic fractures.

Between 1972 and 1993, 1899 patients with fractures of the pelvis were treated at the authors institution. The pelvic ring was fractured in 1479 patients, and 1029 sustained polytrauma. A retrospective study included four parts: (1) Demographic analysis of 1409 patients showed an increase in the severity of pelvic and general trauma during this period. The 17.7% mortality rate was predicted by the Hannover Polytrauma Score and associated extrapelvic blunt trauma. (2) Residual displacement after operative treatment of the pelvis was analyzed in 221 patients. In C type (Tile) fractures residual displacement correlated with external fixation and solely anterior stabilization. (3) Outcome after operative treatment was analyzed in a consecutive series of 58 patients an average of 2.2 years after trauma. Pelvic pain was frequent (Type B 11%, Type C 66%) and correlated with posterior displacement over 5 mm and primary neurological injuries. (4) Mortality after complex pelvic trauma (pelvic fracture with soft tissue injury) decreased from 48.1% to 29.6% during these years. Standardized protocols for primary care and operative procedures of pelvic injuries optimize therapy. Complex pelvic trauma requires early, aggressive surgical management with surgical hemostasis. Further developments in open reduction and internal fixation of the pelvis focus on minimizing additional soft tissue trauma and implants.

Adolescent↗
PubMed1994

The patellar tendon graft for PCL reconstruction. Morphological aspects in a sheep model.

Surgical reconstruction of the PCL has not yet gained the acceptance that ACL reconstruction has achieved. However, in selecting an autograft to restore PCL function in symptomatic posterior knee instability, the free patellar tendon autograft is commonly used at present. Knowledge of the basics in graft healing and of factors regulating this healing process are still limited. It is of interest to determine the biologic response and final morphology of a patellar tendon autograft after PCL replacement. Based on morphological studies in PCL replacement in a sheep model the patellar tendon autograft under-goes necrosis and degeneration followed by a gradual healing process comprising revitalization (i.e. revascularization and cellular proliferation), formation of extracellular matrix components and remodeling. The autograft bone pegs become osseointegrated by 6 weeks. After 2 years, the autograft tissue differs structurally from a ligament, suggesting that the autograft may never approach normal ligament characteristics. Degenerative alterations in the core region of the autograft, the widespread presence of type III collagen and fibronectin, as well as the predominance of thin collagen fibrils do not favor a ligamentization process. The understanding of the autograft healing process remains the prerequisite for a realistic assessment of the biologic PCL replacement and will be a baseline of studies with the goal of influencing the healing process and thus improving the clinical results.

Animals↗
PubMed1994

[Long-term results of therapy of polytrauma patients with special reference to serial fractures of the lower extremity].

A random group of multiple traumatized patients (n = 50) was compared from the aspects of physical rehabilitation and social reintegration with a group of multiple traumatized patients (n = 54) all of whom had serial fracture of the lower extremity. In both groups automobile accidents were the main reason for the injury (in 62%). Motorcycle accidents were responsible in 29% of cases but resulted in twice as many extremity injuries as car accidents, in addition to which the treatment of patients with serial extremity injury lasted twice as long as that of those patients with only single extremity injury. In 40% of the first group more than two secondary hospital treatments were necessary. Two years after trauma working capacity was reduced by less than 20% in only 28.8% of patients with serial injuries as against 69.2% in the randomized group. Reduction of working capacity by more than 80% was observed in only 9% of patients in both groups. In these cases reduction of working capacity was mainly due to severe head injuries and not to limb fractures. Return to work was achieved only after retraining in most such cases, while in others a transfer within the same company made it possible. When patients were asked for their own opinions on the final results of treatment, 75% said they were satisfied. Our results underscore the importance of reestablishing normal function and of reintegration after extremity injuries but also the problems involved.

Adolescent↗
PubMed1994

[A new procedure for determination of leg length and differences in leg length using sonography. I. Development and experimental studies].

The precise measurement of leg length and leg length discrepancies (LLD) plays an important role in the examination of lumbar spine and lower extremities. Those real LLD which may be posttraumatic or idiopathic, can sometimes hardly be differentiated from LLD caused by spinal scoliosis or malposition. Although there is no final agreement, to which extent a LLD becomes clinically significant, most authors state that clinical assessment of LLD by tape measure or lengthening of the short leg with blocks of known thickness is highly unreliable. Radiological methods are necessary for precise detection of LLD less than 10 mm. Since previously reported non-invasive, ultrasound-supported leg-length measurement methods proved to be complicated and unhandy, a new method was developed. To avoid radiation exposure accuracy and precision were tested on human cadavers and were compared to clinical assessments by tape measurement. A measurement device was constructed consisting of a wire rope meter and a length millimeter digital display. Measurements were taken with the examined person in supine position. The device was placed beyond their feet and the end of the rope was hinged with a metal brace to a convenient transducer in exact middle position. Thus the middle of the ultrasound monitor concords with the end of the rope. The medial knee joint and ventral hip joint were used as standardised sonographic landmarks. Ten not pre-selected mortants were measured in this manner and additionally clinical LLD was obtained with a tape measure (medial ankle to anterior superior iliac spine). Afterwards all distances were anatomically prepared and measured with a meter stick.(ABSTRACT TRUNCATED AT 250 WORDS)

Equipment Design↗
PubMed1994

[Scores as decision aids].

Scoring systems are nowadays said to be helpful in decision-making in preclinical and early clinical treatment of multiple trauma patients. To evaluate the importance of these scores in daily routine, we analysed the scores routinely used in our department at the Hannover Medical School. We present three scoring systems: the Polytrauma Score, the Pelvis Score, and the Hannover Fracture Scale. All of these have certain qualities relevant to the aspects of decision-making and prognostic value. The evaluation demonstrates that these scoring systems are genuinely helpful, especially for the inexperienced.

Adult↗
PubMed1994

Isolated traumatic dislocation of the hip. Long-term results in 50 patients.

From 1974 to 1989, we treated 50 patients with a simple dislocation of the hip: 38 were posterior dislocations and 12 were anterior. All dislocations primarily treated at our hospital were reduced by closed methods within three hours (mean 85 minutes (10 to 180)) and 43 were reviewed after an average follow-up of 8 years (2 to 17). It is widely held that isolated hip dislocation reduced within six hours gives an excellent outcome, but we found a significant number of complications. There were radiological signs of partial avascular necrosis in two, mild osteoarthritis in seven, and moderate degeneration in two. Heterotopic ossification was seen in four patients, but 29 of 33 MRI examinations were normal. Objective evaluation according to the Thompson and Epstein (1951) criteria showed fair and poor results in 3 of 12 anterior dislocations, but in 16 of 30 posterior dislocations. In six of the seven patients with no other severe injury, the hip had an excellent or good result; in only three of the eight patients with severe multiple injuries was this the case. The important factors in the long-term prognosis appear to be the direction of the dislocation and the overall severity of injuries.

Adolescent↗
PubMed1993

[Effect of continuous change in axial position in treatment of post-traumatic lung failure (ARDS). A clinical study].

In the treatment of posttraumatic adult respiratory distress syndrome (ARDS) so far no breakthrough has been achieved. In several cases of severe ARDS we have seen improvements of lung function by means of continuous body positioning. We therefore compared the effect of kinetic positioning (KIN) on lung function and hemodynamics in ARDS patients to conventional (KON) supine positioning. 22 ARDS patients with multiple trauma treated by supportive continuous body positioning (KIN) (KCI-Mediscus) and without continuous positioning (KON) were investigated daily. Pulmonary and systemic hemodynamics were determined on the basis of pulmonary artery catheter measurements. Oxygenation ratio (PaO2/FiO2) and pulmonary shunt (Qs/Qt,%) were calculated. Extravascular lung water (EVLW, ml/kg body weight) was determined by double indicator thermodilution technique. Total injury severity by injury severity score (ISS) was 29.6 +/- 6 points (KIN) and 31.6 +/- 5 points (KON). The oxygenation ratio (PaO2/FiO2) increased significantly from 140 +/- 45 (day 0) to 237 +/- 40 (p < 0.05) [day 5] (KIN), in KON patients no improvement (143 +/- 48 [day 0], 133 +/- 44 [ay 5]) was seen (p < 0.05 between groups). There were no significant changes of systemic hemodynamics between the groups or compared to day 0. Pulmonary shunt decreased significantly from 26.6 +/- 4% (day 0) to 12.5 +/- 2% (day 5) (p < 0.05) in KIN patients and was 36.6 +/- 6% at day 0 and 31.4 +/- 2% at day 5 in KON patients (p < 0.05 between groups). EVLW was 11.1 +/- 2 ml/kg body weight at day 0 and 9.4 +/- 1 ml/kg body weight at day 5 (KIN)-EVLW was 12.9 +/- 2 ml/kg body weight at day 0 and 17.4 +/- 3 ml/kg body weight at day 5 (KON) (not significant). We found no hemodynamic side effects from continuous body positioning. In ARDS-patients submitted to body positioning oxygenation and pulmonary shunt improved significantly and were significantly better compared to those with conventional supine positioning. Continuous body positioning appears to represent a promising supportive treatment regimen in posttraumatic ARDS.

Adolescent↗
PubMed1993

A new solid unreamed tibial nail for shaft fractures with severe soft tissue injury.

In a prospective study, 51 tibial shaft fractures with severe open or closed soft tissue damage were treated with a new, thin (8 mm or 9 mm) solid locking nail, inserted without reaming. At 6 months or more after trauma, 43 cases were reviewed. Fractures were classified according to Müller with six type A, 25 type B, and 12 type C fractures. In 13 cases there was group II (n = 8) or group III (n = 5) closed soft tissue damage (Tscherne). Of 30 open fractures, 16 were group OII, six were group OIIIA and eight were group OIIIB (Gustilo). Postoperative treatment in 42 of 44 cases was possible without additional cast or brace. Full weight bearing was achieved in 26 cases within 12 weeks, and in 42 cases within 26 weeks. In 43 cases, fracture healing occurred with a mean of 21.9 weeks (range 12-40 weeks). There was one case with valgus of 6 degrees and three cases with anterecurvatum deformities of 5 degrees to 10 degrees. In four cases there was an external rotation malalignment between 10 degrees and 20 degrees. In three cases we found an internal rotation deformity of 10 degrees to 20 degrees. Shortening between 0.5 and 1.0 cm was found in five cases, and in one case shortening was 1.5 cm. None of the patients had an osteomyelitis.

Adolescent↗
PubMed1993

Fixation of transforaminal sacrum fractures: a biomechanical study.

A transforaminal fracture of the sacrum usually represents the posterior part of an unstable pelvic ring fracture and is associated with a high rate of neurological complications. Nerve root decompression combined with open reduction and internal fixation (ORIF) can be beneficial. Present fixation methods have the disadvantage of extensive bilateral posterior approaches and fixation across the sacroiliac joint. Three methods of internal fixation of the sacrum were compared in a biomechanical study using six fresh pelvic specimens. A fracture model consisting of a transforaminal osteotomy combined with a symphysis disruption in a single-leg stance was used. Standard Harrington sacral bars, an internal fixator, and a newly developed stabilization technique using adapted standard AO/ASIF small-fragment implants ("local osteosynthesis") were compared. Three-dimensional measurement of the fragment movement (goniometer system) showed a maximum displacement of 4.0-4.5 mm after maximal loading (990-1,181 N) and no differences among the implants. The failure load related to body weight was 85% for sacral bars, 74% for the local osteosynthesis, and 58% for the internal fixator. Major displacement under loading was observed in the direction of the foramen axis. The new osteosynthesis technique showed strength comparable to the clinically successfully applied method of stabilization with sacral bars. It adds the theoretical advantage of a minimized approach, without fixation and thus without involvement of the SI joints.

Biomechanical Phenomena↗