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E Hartwig

Publications and source records attributed to E Hartwig.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Combined posterior and anterior endoscopic supported instrumentation of the thoracic and lumbar spine. Arguments, concepts and first clinical results].

The operative therapeutic principles of thoracic and lumbar spine injuries are based on reposition, decompression and stabilization of the unstable area. Secondary loss of correction and consecutive deformation have negative impact on the long-term results after defect fractures of vertebral bodies and will be minimized only by the reconstruction of all involved spinal columns. With dissemination of thoracoscopic techniques at the thoracic spine and minimal invasive retroperitoneal approaches at the lumbar spine a decrease of the morbidity was achieved with equal effectivity for recalibration and fusion. Our experiences with the first consecutive 42 patients, treated minimal invasive are presented. Indications for anterior thoracoscopic and minimal invasive instrumentations after posterior transfixation are remaining osseous defects of the end plates of more than a quarter of the volume of the involved vertebra in case of migration of the vertebral disc, wedging of the vertebral body after posterior reposition of more than 10 degrees and persisting anterior encroachment of the spinal canal of more than 30 %. The decision is based on radiographs and CT-scans, performed after posterior stabilization.

Bone Transplantation↗
PubMed2001

Spinal navigation in cervical fractures--a preliminary clinical study on Judet-osteosynthesis of the axis.

OBJECTIVE: To evaluate the accuracy of CT-based and computer-aided screw insertion into the pedicles of the axis using the method of Judet. Materials and Methods In two patients, four transpedicular implants of C2 were positioned using a computer-guided technique. One patient with iatrogenic destabilization of the posterior structures C3 and C4 and one patient with a hangman's fracture of the axis required pedicular fixation. In addition, intraoperative documentation of the additional time required for the navigation procedures was made. Finally, postoperative CTs of each patient provided further information about transpedicular implant localization. RESULTS: Image-guided implantation of screws was possible in all scheduled pedicles of the axis. In the postoperative CT scans, none of the inserted screws perforated the medial or lateral pedicle. All screws were accurately positioned within the pedicles, and no anterior perforation of the screws into the vertebral foramen was observed. CONCLUSIONS: Our initial results using computer-aided implantation of Judet screws showed that these screws were inserted correctly. However, it is important to realize that movements can occur in the vertebral arch and lateral mass during the time between preoperative CT and surgery. This possibility for movement should be taken into account when procedures such as CT-based insertion of image-guided screws into patients with fractures of the isthmus C2 are performed, because damage to neurovascular structures can result. Therefore, this navigation system should only be used by experienced surgeons who can, if necessary, continue the intervention with more conventional techniques. In addition, it is essential that the surgeon have a complete understanding of the principles of the tracking systems to prevent possible misinterpretation of computer-generated information.

Adult↗
PubMed2001

[Precision analysis of navigation-assisted implanted thoracic and lumbar pedicled screws. A prospective clinical study].

A prospective clinical trial was performed to study the accuracy of pedicle screw placement of consecutive computer-aided and conventional techniques. Concerning the clinical performance of the navigation system, the average time of matching has been 8.4 minutes per vertebrae. For evaluation of the results, only complete intraosseous placement of the pedicle screw has been defined as correct position. Any medial or lateral perforation of the cortical structure of the pedicle was recorded as malplacement. In the CT-controlled patients complete intrapedicular placement of the screw was obtained in 36 of 45 thoracic (80%) and in 22 of 27 navigated lumbar (81%) pedicles. In the conventional cohort group 27 of 34 (79%) thoracal and 43 of 52 (83%) lumbar screws were completely in. No radicular neurologic damage, caused by a malplaced transpedicular screw has been observed in both groups. In the presented study is shown, that the application of the computer-assisted freehand navigation can improve results concerning the precision of spinal screw placement. Although, the spinal navigator has to consider a learning curve for the clinical inauguration of the system and the qualification of the implant system for computer-assisted application.

Bone Plates↗
PubMed2001

Height of lumbar discs measured from radiographs compared with degeneration and height classified from MR images.

The relation between height of lumbar discs (measured from lateral radiographic views) and disc degeneration (classified from MR images) deserves attention in view of the wide, often parallel or interchanged use of both methods. The time sequence of degenerative signs and decrease of disc height is controversial. To clarify the issue, this cross-sectional study documents the relation between disc degeneration and disc height in a selected cohort. Forty-three subjects were selected at random from a cohort examined for potential disc-related disease caused by long-term lifting and carrying. From each subject a lateral radiographic view of the lumbar spine as well as findings from an MR investigation of (in most cases) levels T12/L1 to L5/S1 were available; thus, n = 237 lumbar discs were available for measurement and classification. Disc height was measured from the radiographic views with a new protocol compensating for image distortion and permitting comparison with normal, age- and gender-appropriate disc height. Degeneration as well as disc height were classified twice from MR images by independent observers in a blinded fashion. Disc degeneration classified from MR images is not related to a measurable disc height loss in the first stage of degeneration, whereas progressive degeneration goes along with progressive loss of disc height, though with considerable interindividual variation. Loss of disc height classified from MR images is on average compatible with loss of disc height measured from radiographs. In individual discs, however, classification of height loss from MR images is imprecise. The first sign of disc degeneration (a moderate loss of nucleus signal) precedes disc height decrease. As degeneration progresses, disc height decreases. Disc height decrease and progress of degeneration, however, appear to be only loosely correlated.

Adult↗
PubMed2001

Surface electromyography-verified muscular damage associated with the open dorsal approach to the lumbar spine.

The dorsal approach is increasingly preferred in the surgical treatment of vertebral fractures. However, the access and the implant's position cause muscle loss, which can lead to instability and a reduced capacity for rehabilitation. Morphological factors (bones, intervertebral discs) are typically blamed for chronic pain syndromes in the literature, while less importance is attached to functional factors (muscles). The objective of this study was therefore to investigate the isolated influence of dorsal spinal instrumentation on the back muscles by means of electromyography (EMG). A total of 32 patients with conditions after dorsal spondylodesis following the fracture of a vertebral body and 32 subjects with healthy backs were enrolled in this study. The EMG signal was recorded in three different muscle groups during isometric extension exercise. The evaluation was performed by comparing the mean rectified amplitudes of the three muscle groups in the patients and controls. The patients had significantly lower amplitudes in the multifidus muscle (MF) and significantly higher amplitudes in the iliocostal muscle (IL). Patients with severe pain were found to have lower electric muscle potentials in all investigated muscle groups than patients with mild pain. The muscle damage which was established in the multifidus muscle is compensated by increased activity in the iliocostal muscle. On the basis of anatomical considerations, the damage pattern can be identified as having been caused by surgery. It is extremely unlikely that trauma is the cause.

Adolescent↗
PubMed2001

[Incidence of complications of the screw osteosynthesis of odontoid process fractures].

In this retrospective clinical study the incidence of complications in 58 consecutive, with anterior screw fixation stabilized patients after fractures of the odontoid process is evaluated. In 51 patients the fracture has been defined as type II according to Anderson, in 6 patients an oblique type II fracture was present and one patient showed a cephalad type III fracture. Preoperatively, in only 19 % of the patients (n = 11) no dislocation of the dens occurred. 32 patients were treated with single screw osteosynthesis, in 26 patients two screws were implanted. Significant complications with clinical relevance were registered in 14 patients (24 %), in 10 cases (17 %) an operative reintervention was required. Intraoperatively, in one patient a rupture of the carotid artery while winding around the motor drill occurred and in another case a complete malplacement of the screw posteriorly to the odontoid process was observed. A clearly excentric positioning of the implant was evaluated in 5 patients with a consecutive high rate of implant migration (n = 3). Two patients died perioperatively not related to the cervical injury. Postoperatively, one patient with a wound infection due to an iatrogenic perforation of the esophagus required reoperation as well as 4 patients with instability because of implant migration. Patients beyond the age of 65 years (n = 3) were significantly overrepresented in that group. In one case, the secondary intervention was caused by a pseudarthrosis of the dens axis. Complications without any relevance to the clinical and functional long term result were fusions in malposition of the odontoid process in 14 patients (24 %) and 10 (17 %) marginal screw perforations laterally. Differences in the use of one or two screws have not been observed in this study, although the investigations showed a tendency between marginal lateral screw perforations and double screw osteosynthesis and an increasing number of complications in the geriatric cohort.

Adolescent↗
PubMed2000

[Therapy of aneurysmal bone cyst].

The aneurysmal bone cyst represents a tumor-like lesion, which does not occur frequently. Every site of the skeleton may be involved. Although it can be observed at any age, it distinctly predominates from 10 to 20 years of age. Distinction of aneurysmatic bone cysts from certain benign or malignant bone tumours requires subtle imaging techniques and an experienced bone tumour pathologist. Since the lesion shows a heterogeneous biological behaviour and typically occurs in the growing skeleton, a wide range of surgical procedures must be provided concerning tumour resection and defect reconstruction. In the current retrospective study results of 41 surgically treated aneurysmal bone cysts, thereof 5 latent, 31 active, and 5 aggressive lesions, were investigated. While morbidity due to the therapeutic measures was comparatively low even in extended lesions and demanding reconstructions, a recurrence rate of 19.5% had to be observed in our series. Taking into consideration the biological activity of the lesion, analysis of the recurrences revealed inappropriate surgical margins had been chosen at the primary operation in all of these patients. Since the risk of a local relapse is linked both to aggressiveness of the primary lesion and to surgical radicality, therapy of aneurysmal bone cyst requires preoperative staging and stage-dependent surgical procedures.

Adolescent↗
PubMed2000

[Tuberculous spondylitis of the cervical spine].

WHO estimates that worldwide more than 4 million people are infected with tuberculosis (TB), 95% of them living in third world countries. TB is once again the most frequent infectious disease [1, 2, 7]. Extrapulmonary forms (EPTB) frequently appear with HIV-associated TB [3, 4, 6]. We present the case of a 23-year old patient with abscess forming TB of the right apical lung with infiltration and partial osteolytical destruction of the 7th cervical- and the first thoracal vertebral body. Progressive spinal compression lead to partial sensomotorical deficits. Surgical revision of the abscess, an atypical resection of the right apical lung and right wing hemilaminectomy of Th1/2 for spinal decompression became necessary. The spinal stabilisation was achieved by conservative treatment for 6 weeks only by a Minerva cast and for another 8 weeks by a cervical stiffneck. Following mobilisation was without problems and the neurological deficits subsided within 3 months. Clinical examination and functional X-rays analysis proved vertebral stability and good function. The treatment of TB is basically conservative. Surgery is only recommended in case of functional and infectious complications.

Abscess↗
PubMed2000

[Temporary instrumentation in dixlocations, subluxations and fractures of the lower cervical spine].

The anterior interbody fusion with instrumentation seems to be the standard procedure in unstable traumatic lesions of the lower cervical spine. The goal of this study was to objective the outcome of patients, treated by only temporary stabilisation of the injured motion segment (without bone-graft fusion). Between 1990 and 1998 155 patients with traumatic lesions of the cervical spine were treated operatively, in 22 cases transfixation of the injured level without bone-graft application was performed, an implant-removal was carried out in 12 patients so long. Only patients were included into the study, who were less then 45 years old at trauma and who had no trauma related osseous or disc encrouchment of the spinal canal. Not included were patients with degenerative formations of the cervical spine at time of trauma. Until follow up all patients with implantat removal returned back to work in their former profession, 11 of 12 patients classified their result as excellent or good. No secondary instabilities or postraumatic disc prolapse were observed. Restmobility in flexion/extension of the injured level was demonstrated in 8 patients. The preservation of traumatized motion segments may reduce the incidence of degenerative alterations and hypermobilities in adjacent levels. The transfixation technique in anterior procedures leads to a reduced time of spinal exposure, complications as a result of spinal graft manipulation, pseudarthrosis or donor graft site problems are no more relevant.

Adult↗
PubMed2000

Spinal cord injury without radiographic abnormalities in children and adolescents: case report of a severe cervical spine lesion and review of literature.

The biomechanics of the child's and juvenile's spine is responsible for the commonly encountered closed spinal trauma with significant neurological injury but without bony or ligament injury (particularly of the cervical spine). The ligamentous laxity and hypermobility of the young bony cervical and thoracic spine predispose to spinal cord injury without radiographic abnormalities. We report a 16-year-old girl with typical features of this type of injury after a "flic-flac" sports injury. We conclude that children and adolescents who have neurological deficits without positive radiographic findings require appropriate diagnostic screening, monitoring, and often a prolonged therapy. The sometimes changing neurological deficits should never be ignored or dismissed as psychogenic affection.

Adolescent↗
PubMed2000

Vertebral body replacement with a bioglass-polyurethane composite in spine metastases--clinical, radiological and biomechanical results.

Metastatic spine lesions frequently require corpectomy in order to achieve decompression of the spinal cord and restoration of spinal stability. A variety of systems have been developed for vertebral body replacement. In patients with prolonged life expectancy due to an improvement of both systemic and local therapy, treatment results can be impaired by a loosening at the implant-bone interface or mechanical failure. Furthermore, early detection of a metastatic recurrence using sensitive imaging modalities like computed tomography (CT) and magnetic resonance imaging (MRI) is possible in these patients without artefact interference. The aim of our pilot study was to evaluate the clinical applicability and results of a new radiolucent system for vertebral body replacement in the lumbar spine. The system consists of bone-integrating biocompatible materials - a polyetherurethane/bioglass composite (PU-C) replacement body and an integrated plate of carbon-fibre reinforced polyetheretherketone (CF-PEEK) - and provides high primary stability with anterior instrumentation alone. In a current prospective study, five patients with metastatic lesions of the lumbar spine were treated by corpectomy and reconstruction using this new system. Good primary stability was achieved in all cases. Follow-up (median 15 months) using CT and MRI revealed progressive osseous integration of the PU-C spacer in four patients surviving more than 6 months. Results obtained from imaging methods were confirmed following autopsy by biomechanical investigation of an explanted device. From these data, it can be concluded that implantation of the new radiolucent system provides sufficient long-term stability for the requirements of selected tumour patients with improved prognosis.

Adult↗
PubMed2000

Comparative stability of the "Internal Fixator" and the "Universal Spine System" and the effect of crosslinking transfixating systems. A biomechanical in vitro study.

In this study, the three-dimensional stabilizing capabilities of the AO-Internal Fixator (IF) and the new Universal Spine System (USS) were investigated. Both devices were tested without and with the cross-link system (IF, IFC, USS, USSC). To determine biomechanical characteristics, a human thoracolumbar spine instability model with resection of the vertebral body Th12 was created. The vertebral body was replaced by a spacer and transpedicular posterior stabilization was performed from Th11 to L1. All devices reduced the range of motion (ROM) significantly compared to the values of the intact specimen. In flexion the IFC showed the highest reduction of ROM (85% of intact), followed by the USSC, USS and IF (79% of intact). In extension the ROM was restored again most by the IFC (52% of intact), followed by the USSC, IF and USS (44% of intact). In lateral bending stability was provided by the USSC (right 78% and left 81% of intact), followed in right lateral bending by the IF, IFC and USS and in left lateral bending by the USS, IF and IFC. In axial rotation the ROM was reduced primary by the IFC (right 51% and left 46% of intact), followed in right axial rotation by the USS, USSC and IF, in left axial rotation by the USSC, USS and IF. Additional stability by crosslinking has been provided in the IF and the USS in flexion and extension, in the USS in lateral bending and in the IF in axial rotation nonsignificantly. The neutral zone (NZ) was reduced by posterior instrumentation in flexion/extension and right/left lateral bending significantly. In axial rotation only the USSC decreased the NZ below intact levels. The study showed no statistical significant differences in the stabilizing capabilities of the USS compared to the IF. For both implants the cross-link system increased stability in the chosen instability model insignificantly only.

Aged↗
PubMed2000

Grading of tumors and tumorlike lesions of bone: evaluation by FDG PET.

UNLABELLED: Clinical diagnosis of skeletal tumors can be difficult, because such lesions compose a large, heterogeneous group of entities with different biologic behaviors. The aim of this prospective study was to assess the value of PET in grading tumors and tumorlike lesions of bone. METHODS: Two hundred two patients with suspected primary bone tumors were investigated using FDG PET. Uptake of FDG was evaluated semiquantitatively by determining the tumor-to-background ratio (T/B). All patients underwent biopsy, resulting in the histologic detection of 70 high-grade sarcomas, 21 low-grade sarcomas, 40 benign tumors, 47 tumorlike lesions, 6 osseous lymphomas, 6 plasmacytomas, and 12 metastases of an unknown primary tumor. RESULTS: All lesions, with the exception of 3 benign tumors, were detected by increased FDG uptake. Although sarcomas showed significantly higher T/Bs than did latent or active benign lesions (P < 0.001), aggressive benign lesions could not be distinguished from sarcomas. Using a T/B cutoff level for malignancy of 3.0, the sensitivity of FDG PET was 93.0%, the specificity was 66.7%, and the accuracy was 81.7%. CONCLUSION: FDG PET provides a promising tool for estimating the biologic activity of skeletal lesions, implicating consequences for the choice of surgical strategy.

Adult↗
PubMed1999

Fluorodeoxyglucose positron emission tomography of soft tissue tumours: is a non-invasive determination of biological activity possible?

Since musculoskeletal tumours comprise a large heterogeneous group of entities with different biological behaviour, clinical diagnosis of such lesions can be very difficult. The aim of this prospective study was to assess the usefulness of 2-[F-18]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) in the non-invasive evaluation of soft tissue tumours. One hundred and two patients with suspected soft tissue neoplasms were investigated by FDG-PET. The uptake of FDG was evaluated semiquantitatively by determining the tumour to background ratio (TBR). All patients underwent biopsy, resulting in the histological detection of 39 high-grade sarcomas, 16 intermediate-grade sarcomas, 11 low-grade sarcomas, 25 benign tumours, 10 tumour-like lesions such as spontaneous myositis ossificans (n = 6) and one non-Hodgkin lymphoma. All lesions except for two lipomas disclosed an increased FDG uptake. Sarcomas showed significantly higher TBR values than latent or active benign lesions (P<0.001) and aggressive benign lesions (P<0.05). Using a TBR cut-off level of 3.0 for malignancy, sensitivity of FDG-PET was 97.0%, specificity 65.7% and accuracy 86. 3%. From our data there are three main conclusions: (1) Except for patients with pseudotumoral myositis ossificans, lesions with a TBR >3 were sarcomas (91.7%) or aggressive benign tumours (8.3%). (2) Tumours with a TBR <1.5 were latent or active benign lesions, exclusively. (3) The group with intermediate TBR values (<3 and >1. 5) comprised primarily latent or active benign lesions, but also four aggressive benign tumours and two low-grade sarcomas. Our data suggest that FDG-PET represents a useful tool for the evaluation of the biological activity of soft tissue neoplasms.

Female↗
PubMed1999

Evaluation of neoadjuvant therapy response of osteogenic sarcoma using FDG PET.

UNLABELLED: According to the current treatment protocol of the Cooperative Osteosarcoma Study (COSS), monitoring preoperative chemotherapy response and estimating grade of tumor regression in patients with osteosarcoma is mandatory before surgical removal of the tumor, particularly if a limb salvage procedure is intended. In addition, response to neoadjuvant chemotherapy is considered as an important prognostic indicator. The aim of this prospective study was to assess the usefulness of 2-(18F) fluoro-2-deoxy-D-glucose (FDG) PET in the noninvasive evaluation of neoadjuvant chemotherapy response in osteosarcoma. METHODS: In 27 patients with osteosarcoma, we determined tumor-to-background ratios (TBRs) of FDG uptake with PET, before and after neoadjuvant chemotherapy according to COSS 86c or COSS 96 protocols, respectively. We compared changes in glucose metabolism of osteosarcomas with the histologic grade of regression in the resected specimen, according to Salzer-Kuntschik, discriminating responders (grades I-III; n = 17) and nonresponders (grades IV-VI; n = 10). RESULTS: The decrease of FDG uptake in osteosarcomas expressed as a ratio of posttherapeutic and pretherapeutic TBRs showed a close correlation to the amount of tumor necrosis induced by polychemotherapy (P < 0.001; Spearman). With a TBR ratio cutoff level of 0.6, all responders and 8 of 10 nonresponders could be identified by PET. In addition, lung metastases of osteosarcoma were detected with FDG PET in 4 patients. CONCLUSION: FDG PET provides a promising tool for noninvasive evaluation of neoadjuvant chemotherapy response in osteosarcoma. This could imply consequences for the choice of surgical strategy, because a limb salvage procedure cannot be recommended in patients nonresponsive to preoperative chemotherapy unless wide surgical margins can safely be achieved.

Adolescent↗
PubMed1998

[Color Doppler controlled needle biopsy in diagnosis of soft tissue and bone tumors].

In a prospective study we investigated 168 patients with musculoskeletal tumors, including 71 sarcomas, by core needle biopsy using the high-speed device Autovac. Monitoring with colour-coded duplex sonography allowed a well-aimed puncture of smaller or deeply localized lesions and also permitted the discrimination of necrotic and viable parts of the tumor. Adequate material for histologic diagnosis including grading and determination of tumor subtype was obtained from soft tissue sarcomas, soft tissue metastases, malignant lymphomas, plasmacytomas, and osteolytic skeletal secondaries. In contrast, in benign soft tissue and bone tumors the diagnosis could be established in only 66% of cases. Although skeletal sarcomas were identified as malignant mesenchymal lesions, a complete histologic classification of tumor subtype frequently was not possible due to an insufficient tissue specimen. With an accuracy of 97% for the diagnosis of malignancy and of 94% for the diagnosis of soft tissue sarcoma the results of core needle biopsies were comparable to those of incisional biopsies, the reference standard in the diagnosis of musculoskeletal tumors. Regarding the known disadvantages and the oncological risks of incisional biopsies, needle biopsy should replace the open procedure as the primary means of diagnosis in soft tissue and osteolytic bone tumors.

Adult↗
PubMed1998

Soft tissue texture analysis by B-mode-ultrasound in the evaluation of impairment in chronic low back pain.

OBJECTIVE: Patients complaints in chronic low back pain do not always correspond to the results of X-ray and MRI investigations. The paraspinal muscle is very sensitive to all structural disorders of the spine. We used B-mode-ultrasound to investigate the change of the ultrasonic texture of the paraspinal lumbar muscle in people suffering from low back pain. METHODS: The quantitative texture analysis was defined by the ratio of the mean echo level of a unilateral cross-section (L2) of the paraspinal muscle and the level of a central area (L1) of the same cross-section (square 1 x 1 cm, defined by the ultrasonic device). In the lumbar spine there were five cross sections on either side starting at L1 through L5. In the first study healthy males were investigated (n=30). In the second study, 20 males with MRI controlled lumbar disc disorders were investigated. Finally screening was performed with a group of 40 male patients. The last investigation was a pathohistologic cross-check from the ultrasonic findings in five individual shortly after exitus. RESULTS: The ratio showed results >0.6 in the healthy group. The group with lumbar disc disorders showed at the affected levels ratios <0.5. All patients (with one exception) with a lumbar spinal history were detected. Pathohistology confirmed the ultrasonic findings. CONCLUSIONS: The ultrasonic texture analysis of the paraspinal lumbar muscle allows a rapid and easy to perform investigation for relating discal (actually all structural) disorders of the lumbar spine to the reported pain or disability.

Adult↗