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Biomedical subjects

R Zettl

Publications and source records attributed to R Zettl.

At least 19 recordsLinked to original sources
PubMed2004

[The accuracy of palpation from orientation points for the navigated implantation of knee prostheses].

AIMS: Cinematic and pointing procedures are used for non-image based navigated implantation during total knee replacement. Pointing procedures require an exact knowledge of the landmarks. In this anatomical study, landmarks are defined and repeatedly referenced. Precision and reproducibility are evaluated by means of an inter- and an intra-observer study. The axes of the femur and tibia are calculated using the landmarks. MATERIAL AND METHODS: The specific landmarks of 30 femurs and 27 tibias were palpated by three surgeons and digitised by means of a photogrammetric system, as used intra-operatively. The recorded data were statistically evaluated. RESULTS: The specific landmarks can be referenced with great precision. The vectors that influence the implant position show a mean femoral deviation of 0.9 mm and a mean tibial deviation of 1.0 mm. The repeating accuracy of every observer was 1.5 mm femoral and 1.0 mm tibial. The calculated long axes at the femur and tibia thus reach a precision of 0.1 degrees (min.-max.: 0-0.9 degrees) at the femur and 0.2 degrees (.0-1.1 degrees) at the tibia. The short axes at the distal femur and proximal tibia exhibit an average deviation of from 0.7 degrees to 1.9 degrees (0-11.3 degrees). CONCLUSION: Long axes (mechanical axes) can be determined exactly but the precision of the short axes (rotational axes) is unsatisfactory, although palpation of landmarks was accurate. Therefore, palpation of more than one rotational axis at the femur and tibia is mandatory and should be visualized on the monitor during surgery.

Arthroplasty, Replacement, Knee↗
PubMed2002

[Primary external fixation with consecutive procedural modification in polytrauma].

AIM OF STUDY: It is the purpose of the current investigation to determine whether immediate external fixation of fractures, which is a simple and fast procedure, followed by secondary planned conversion represents a safe and reliable procedure without additional trauma in multiply injured patients (ISS > 15). METHODS: With a prospective protocol, all data of multiply injured patients with fractures which required immediate osteosynthesis were registrated. Demographic data, severity of injury (AIS and ISS), data of primary surgery and osteosyntheses, course of intensive care (organ failure, local/systemic complications, infectious protocol), secondary conversion (time, duration, osteosynthesis related complications) and further course were analysed. RESULTS: Out of 679 mulitiply injured patients (ISS 22), 118 required immediate surgical procedures for intracranial injury and 175 for further indications. In 45 multiply injured patients (ISS 37), 83 external fixations were performed. According to 59 planned secondary conversions (13 days), one patient developed deep infection, no other local complication was registrated. The average time for conversion procedures lasted three times longer as in immediate external fixation (43 vs. 139 min). CONCLUSIONS: Immediate external fixation in multiply injured patients is fast and poor of complications. It is a expedient procedure which is safe and careful for critically ill patients. The required conversion procedure shows no raised rate of complications.

Adolescent↗
PubMed2000

Moderate to severe hallux valgus deformity: correction with proximal crescentic osteotomy and distal soft-tissue release.

Between 1991 and 1995, 96 patients (114 feet) were treated with a proximal crescentic metatarsal osteotomy and distal soft-tissue procedure for moderate to severe hallux valgus deformity [intermetatarsal (IM) angle > 15 degrees, or hallux valgus (HV) angle > 30 degrees]. At an average follow-up of 26 months, 8 men and 62 women (86 feet) with a mean age of 53.2 years were retrospectively reviewed. The HV angle averaged 41.1 degrees preoperatively and 14.6 degrees postoperatively. The respective values for the IM angle were 17.8 degrees and 7.8 degrees. Neither the average metatarsal shortening of 3 mm nor the dorsal angulation at the osteotomy site seen in 9% of cases evidenced any clinical significance at follow-up. Patient satisfaction was excellent or good in 91%, and the mean Mayo Clinic Forefoot Score (total 75 points) improved from 37.2 to 61.1 points. Complications included 8 cases of hallux varus and 5 cases of hardware failure. Based on this first study exclusively focusing on moderate to severe hallux valgus deformity, we conclude that proximal first metatarsal osteotomy in combination with a lateral soft-tissue procedure is effective in correcting moderate to severe symptomatic hallux valgus deformity with metatarsus primus varus (IM angle > 15 degrees or HV angle > 30 degrees).

Adolescent↗
PubMed2000

[Stable and unstable pertrochanteric femoral fractures. Differentiated indications for the dynamic hip screw].

The aim of all surgical procedures in the treatment of trochanteric fractures in elderly and even geriatric patients is achievement of initial stability. We examined in a clinical trial whether primary stability was achieved in all types of trochanteric fractures following osteosynthesis with the Dynamic Hip Screw (DHS). From 1994 to 1996, 122 patients with trochanteric fractures had osteosynthesis by dynamic hip screw. Patient records were evaluated and all data got registered with a standardized protocol;clinical radiological outcome was analysed after an average period of 1.9 years after injury according to the Traumatic Hip Rating Score. 22% of all patients died meantimes, 51.6% of the remaining 95 patients could get examined. The average age was 75.5 years, the patient population showed an increased preoperative morbidity (2.5 points) according to ASA-Score. 81% showed progressive osteoporosis. According to the AO-classification 47% stable fractures (type A-1) and 53% instable trochanteric fractures (type A-2 and A-3) occurred. Surgery lasted 77 minutes average in osteosynthesis of stable fractures. The duration of 108 minutes in instable fractures was significantly higher, as well as the blood loss was 43% increased in these complex fractures. Complications closely associated to the osteosynthesis appeared only in instable fractures (7%). Also common complications (24.6%) predominated with 15.6% in type A-2 and A-3 fractures versus 9% in type A-1 fractures; mortality was also different with 5.7% versus 1.6%. Assessment of the functional outcome according to THRS showed a significant deterioration of 20 points in 71% of all patients compared with the preoperative score. The results show that dynamic hip screw osteosynthesis in instable trochanteric fractures is associated to a higher incidence of complications. While the dynamic hip screw still represents the standard implant in stable fractures of the trochanteric region, being aware of improved intramedullary implants regarding biomechanical features and surgical technique, the results justify to critical consider the use of DHS for osteosynthesis in instable fractures of the trochanteric region.

Aged↗
PubMed1999

Comparison of the results of the Weil and Helal osteotomies for the treatment of metatarsalgia secondary to dislocation of the lesser metatarsophalangeal joints.

We retrospectively reviewed the outcome of 30 patients who were treated surgically for metatarsalgia resulting from dislocation of one or more lesser metatarsophalangeal (MTP) joints. We used two treatments, including an osteotomy of the metatarsal head (Weil osteotomy, N = 15) or an osteotomy of the metatarsal shaft (Helal osteotomy, N = 15). Before surgery, all patients had been treated with various nonoperative modalities for a minimum of 6 months. Between 1991 and 1993, 15 consecutive patients underwent a Helal osteotomy (22 metatarsals), and 15 consecutive patients were subsequently treated between 1994 and 1995 with a Weil osteotomy (25 metatarsals). All patients were evaluated clinically and radiographically at a mean follow-up period of 22 months (range, 12-39 months), noting especially persistent subluxation or dislocation, recurrent metatarsalgia, and transfer lesions. Patients managed with a Weil osteotomy had significantly higher satisfaction (P = 0.049), lower incidence of recurrent metatarsalgia (0 vs. 27%, P = 0.107), and fewer transfer lesions (0 vs. 41%, P = < 0.001) than those managed with a Helal osteotomy. Furthermore, those managed with the Weil procedure had a higher percentage of radiographic reduction and maintenance of the MTP joint dislocation (21 of 25, 84%; vs. 8 of 22, 36%; P = 0.002) than those managed with the Helal procedure. In the Weil group, there was also no malunion or pseudoarthrosis; in the Helal group there were five malunions and three pseudoarthroses. Although the follow-up period for the Weil osteotomy (15 months) was shorter than that for the Helal osteotomy (26 months), the former group had higher American Orthopaedic Foot and Ankle Society forefoot scores, which were significantly different from the results attained with the Helal osteotomy. A telephone update was performed on the Weil osteotomy group at an average of 27 months postsurgery, and no patient had experienced changes since the clinical follow-up. We concluded that the Weil procedure is a satisfactory method for correcting metatarsalgia caused by dislocation of the MTP joint and that, because of the high complication rate, the Helal osteotomy is not an acceptable procedure for correcting this condition.

Adult↗
PubMed1998

Fracture of the anterior superior process of the calcaneus: an often misdiagnosed fracture.

Fracture of the anterior superior process of the calcaneus has been considered an unusual injury. Following a sudden twist there is immediate pain on the outer aspect of the mid-portion of the foot and discomfort on weight-bearing. Three mechanisms of injury have been reported to cause the fracture. The diagnosis is often missed, and prolonged disability and local pain at the calcaneocuboid joint deserve further consideration. Oblique X-rays of the foot are helpful to visualize the fracture. Type III fractures may cause cartilage lesions and arthrosis; therefore, one should not wait long before excision or refixation of the fragment.

Adult↗
PubMed1997

[Determination of cartilage thickness in the ankle joint. an MRT (1.5)-anatomical comparative study].

PURPOSE: The aim of this study was to evaluate the accuracy of MRI in the measurement of cartilage thickness of the ankle joint in comparison to pathologic and histologic specimens. PATIENTS AND METHODS: The ankle joints of four fresh cadaver feet were imaged on a 1.5T MR-unit in the coronal plane. Standard T1-weighted spin echo (SE) and a T1-weighted 3D-GE (FLASH-3D) sequence with fat saturation were applied. Following MR imaging, the talus was explanted and cut parallel to the MR images for macroscopic evaluation and histologic specimens were prepared. MRI measurements of the cartilage thickness of the talus were carried out in two ways: without and with consideration of a transition zone of intermediate signal intensity between hyperintense cartilage and hypointense cortical bone. The data were compared with the anatomic specimens as the gold standard expressing the difference as a percentage value. On histologic specimens thickness of deep calcified cartilage layer was measured. RESULTS: Measurements without the transition zone showed a mean underestimation of talus cartilage thickness of 46.8% (41.3-52.1) for T1-SE and 47.5% (43.1-52.1) for fat saturated FLASH-3D images. Considering the transition zone the mean values were 25.0% (23.1-26.2) and 14.1% (6.7-21.5). The histologic specimens showed a three-fold increase of thickness of deep calcified cartilage layer. CONCLUSIONS: Measurements of the cartilage layer of the ankle joint on MR images are only accurate if the transition zone (calcified cartilage layer) is considered and the optimal pulse sequence (FLASH-3D-fat-sat) is applied.

Aged↗
PubMed1997

Indicators of the posttraumatic inflammatory response correlate with organ failure in patients with multiple injuries.

BACKGROUND: Most prognostic indices for severely injured patients are based on anatomical findings and the vital signs. The posttraumatic organ failure, however, is thought to be triggered by the initial inflammatory response. The objective of this study was to evaluate the correlation between the early activation of inflammation and the rate of organ failure and death. METHODS: Sixty-six patients with multiple injuries (Injury Severity Score > 18, age 18-70 years, admission within 6 hours after accident, survival > 48 hours) were included in this prospective study. During a 14-day observation period, serial blood samples were collected starting within 30 minutes after admission. Plasma levels of neutrophil elastase, lactate, antithrombin III, and interleukin-6 and -8 were determined. The clinical course and the degree of organ failure were recorded daily until death or transfer to a general ward. RESULTS: The 66 severely injured patients had a mean Injury Severity Score of 40 points. Eleven patients died from multiple organ failure (group 1), 38 subjects survived a single or multiple organ failure (group 2), and 17 patients had an uneventful recovery (group 3). The initial plasma concentrations for neutrophil elastase (650 vs. 355 ng/mL), lactate (5.0 vs. 3.1 mmol/L), antithrombin III (48 vs. 62% from normal), interleukin-6 (703 vs. 177 pg/mL), and interleukin-8 (1,101 vs. 301 pg/mL) were significantly different between groups 2 and 3 already in the initial posttraumatic period. Patients from group 1 presented with significantly higher levels of these parameters as early as 24 hours after trauma compared with group 2. Different patterns were identified with respect to early versus late posttraumatic organ failure. CONCLUSIONS: These data show that the degree of the initial inflammatory response corresponds with the development of posttraumatic organ failure. Besides anatomically and physiologically based trauma scores, these parameters might be used as indicators for the injury severity.

Adolescent↗
PubMed1997

Acquired hallux varus and clinical tolerability.

This retrospective study was undertaken to determine the long-term clinical problems, residual disability, and need for further surgery in patients with iatrogenic hallux varus. Between 1975 and 1985, in 16 (19 feet) of 83 patients who underwent foot surgery for hallux valgus or metatarsus primus varus, hallux varus deformity was noted at 1-year follow-up on dorsoplantar roentgenograms obtained with the patients bearing weight. Thirteen of those patients (16 feet) were reexamined at an average of 18.3 years (220 months) after surgery. The average hallux varus deformity in this group was 10.1 degrees. Eleven patients (12 feet) rated their results as excellent. The average hallux metatarsophalangeal interphalangeal score for all patients was 91.5 points. Only those with extreme hallux varus deformity were dissatisfied or required further surgery.

Adolescent↗
PubMed1996

Three-dimensional structure of glutathione S-transferase from Arabidopsis thaliana at 2.2 A resolution: structural characterization of herbicide-conjugating plant glutathione S-transferases and a novel active site architecture.

Glutathione S-transferases (GST) are a family of multifunctional enzymes involved in the metabolization of a broad variety of xenobiotics and reactive endogenous compounds. The interest in plant glutathione S-transferases may be attributed to their agronomic value, since it has been demonstrated that glutathione conjugation for a variety of herbicides is the major resistance and selectivity factor in plants. The three-dimensional structure of glutathione S-transferase from the plant Arabidopsis thaliana has been solved by multiple isomorphous replacement and multiwavelength anomalous dispersion techniques at 3 A resolution and refined to a final crystallographic R-factor of 17.5% using data from 8 to 2.2 A resolution. The enzyme forms a dimer of two identical subunits each consisting of 211 residues. Each subunit is characterized by the GST-typical modular structure with two spatially distinct domains. Domain I consists of a central four-stranded beta-sheet flanked on one side by two alpha-helices and on the other side by an irregular segment containing three short 3(10)-helices, while domain II is entirely helical. The dimeric molecule is globular with a prominent large cavity formed between the two subunits. The active site is located in a cleft situated between domains I and II and each subunit binds two molecules of a competitive inhibitor S-hexylglutathione. Both hexyl moieties are oriented parallel and fill the H-subsite of the enzyme's active site. The glutathione peptide of one inhibitor, termed productive binding, occupies the G-subsite with multiple interactions similar to those observed for other glutathione S-transferases, while the glutathione backbone of the second inhibitor, termed unproductive binding, exhibits only weak interactions mediated by two polar contacts. A most striking difference from the mammalian glutathione S-transferases, which share a conserved catalytic tyrosine residue, is the lack of this tyrosine in the active site of the plant glutathione S-transferase.

Amino Acid Sequence↗
PubMed1996

Posttraumatic inflammatory response, secondary operations, and late multiple organ failure.

The objective of this study was to determine the role of surgical procedures as secondary inflammatory insults in the development of late multiple organ dysfunction syndrome in patients with multiple trauma and to evaluate both specific and nonspecific indicators of the inflammatory response in their ability to indicate the risk of severely injured patients to develop organ failure after secondary operations. In a prospective study of 106 severely injured patients (ISS 40.6) who underwent secondary operations (> 3 days after trauma), we compared the level of preoperative inflammation with the sequelae of surgical trauma. The interventions included facial reconstructions; osteosynthesis of the pelvic girdle, long bones, and spine; and others. Group 1 consisted of 40 patients (38%) who developed respiratory, renal, or hepatic failure, or combinations thereof, within 2 days after the operation or whose preexisting organ dysfunction worsened by more than 20% from baseline. The remaining 66 patients (62%) with an uneventful recovery formed group 2. The preoperative levels of neutrophil elastase (92.2 vs. 61.3 ng/dL), C-reactive protein (12.4 vs. 7.6 mg/dL), and platelet count (118,000 vs. 236,000/microL) were significantly more abnormal in the patients of group 1. PO2/FiO2 ratio was also somewhat lower in group 1 patients (305.5 vs. 351), whereas other parameters (e.g., blood pressure, heart rate, bilirubin, creatinine, urinary output, lactate, pH, and coagulation) did not allow preoperative differentiation between groups 1 and 2. An increased state of inflammation (neutrophil elastase > 85 ng/mL, C-reactive protein > 11 mg/dL, platelet count < 180,000/microL) predicted postoperative organ failure with an accuracy of 79% (sensitivity, 73%; specificity, 83%). We conclude that secondary operations may act as a second insult and may precipitate late multiple organ dysfunction syndrome if they are performed in patients with multiple trauma while they still have an increased level of posttraumatic inflammation. However, future investigations have to show whether postponing surgery until inflammation has subsided or the use of less invasive surgical techniques will decrease the rate of postoperative organ failure in the trauma patient.

Adult↗
PubMed1996

Helal metatarsal osteotomy for the treatment of metatarsalgia: a critical analysis of results.

We reviewed the results of treatment of 114 feet in 96 patients with pressure metatarsalgia treated with a metatarsal osteotomy performed according to the technique of Helal. Clinical examination was performed according to a standardized evaluation questionnaire using the American Orthopaedic Foot and Ankle Society Lesser Metatarsophalangeal-Interphalangeal Scale. The results were correlated with number of metatarsal osteotomies, the length of the follow up, the age of the patient, and type of additional procedures performed. Sixty-one percent of the patients rated the operation as excellent or good. Patient age and number of osteotomies did not influence the results; however, the length of time following surgery and associated Keller-Brandes resection arthroplasty influenced the outcome negatively. There was a high incidence of increased transfer of weight to adjacent metatarsals. We concluded that the Helal type metatarsal osteotomy is unlikely to predictably achieve symptom relief over a long period.

Adult↗
PubMed1995

Identification of a 23 kDa protein from maize photoaffinity-labelled with 5-azido-[7-3H]indol-3-ylacetic acid.

A 23 kDa protein (p23) was identified in microsomal extracts from maize coleoptiles by photoaffinity labelling with 5-azido-[7-3H]indol-3-ylacetic acid ([3H]N3IAA). Labelling of p23 was blocked by unlabelled IAA, N3IAA, indol-3-ylbutyric acid and indol-3-yl-lactate. In addition, labelling was efficiently decreased by tryptophan, as well as by the scavenger p-aminobenzoic acid. Labelling was, however, not affected by synthetic auxins such as 1-naphthylacetic acid or 2,4-dichlorophenoxyacetic acid. Competition data suggest that the label was probably bound via the indole ring, and hence labelling was not specific for auxins. The 23 kDa protein was solubilized from crude microsomes by extraction with Triton X-100 and purified to homogeneity by ion-exchange, size-exclusion and reversed-phase chromatography. After electroblotting, the amino acid sequences of the p23 N-terminus as well as the several tryptic peptides were obtained. Database comparisons revealed sequence identity with a maize manganese superoxide dismutase. We conclude that photoaffinity labelling of p23 was pseudo-affinity, and therefore the binding site for IAA is not specific.

4-Aminobenzoic Acid↗
PubMed1995

[Postoperative homeostatic imbalance after trauma surgical interventions of various degrees in polytrauma].

The objective of this study was to evaluate and compare the derangement of body homeostatis and the inflammatory response after different types of traumatological operations in patients with multiple injuries. These were determined in a total of 60 operations. The procedures comprised osteosynthesis of the femur (n = 28), the pelvic girdle (n = 11) the spine (n = 8), and facial and basal skull reconstructions (n = 13). Specific and unspecific parameters of the inflammatory response were determined on the morning of the operation, immediately after the procedure, every 6 h on the 1st day and 48 h after the end of surgery. After all types of operations (pelvis, femur, spine, face/basal skull) significant alterations were observed for neutrophil elastase, C-reactive protein, interleukin 6, interleukin 8, antithrombin III, partial thromboplastin time and other parameters. The degree of postoperative changes differed significantly (Kruskal-Wallis test, P < 0.05) among the four types of operations for lactate, heart rate, PO2/FiO2 ratio and nitrogen excretion and showed a strong discriminating tendency for neutrophil elastase and C-reactive protein. The changes were most pronounced after operations on the pelvic girdle, followed by procedures in the femoral, spinal, and facial/basal skull regions. We conclude that a considerable inflammatory response and pronounced disturbance of body homeostasis follow traumatological operative procedures, varying in severity with the type of surgery. Several parameters allow quantitation of the surgical trauma and differentiation between different operations/regions. Further research should focus on the interrelationship between pre-existing preoperative inflammation and the additional trauma inflicted by surgery in patients with severe injuries.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute-Phase Reaction↗
PubMed1994

Characterization of two membrane-associated beta-glucosidases from maize (Zea mays L.) coleoptiles.

We isolated membrane vesicles from maize (Zea mays L.) coleoptiles and identified in these vesicles a 58 kDa (pm58) and a 60 kDa (pm60) protein by photoaffinity labelling with 5-azido-[7-3H]indole-3-acetic acid ([3H]N3IAA). Photoaffinity labelling was effectively competed for by auxins as well as by flavonoids. The labelled proteins were solubilized by Triton X-114 from the vesicles and partially purified. Microsequence analysis revealed that pm60 is a beta-glucosidase. This was confirmed by biochemical and immunological analysis. We show that pm60 has a beta-D-glucoside glucohydrolase (EC 3.2.1.21) activity. It uses p-nitro-phenyl beta-D-glucopyranoside (PNPG) as a substrate, with a pH optimum of 5.0. The Km for PNPG is 0.652 mM and the Vmax. 6.24 mumol.min-1.mg-1. The beta-glucosidase activity of pm60 was competitively inhibited by IAA and 1-naphthylacetic acid as well as by gluconolactam and glucose. N-terminal amino-acid-sequence analysis of pm58 revealed similarity to pm60, suggesting that both proteins are encoded by different members of a gene family.

Affinity Labels↗