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T M Markwalder

Publications and source records attributed to T M Markwalder.

At least 19 recordsLinked to original sources
PubMed1999

Long-term results in patients treated with posterior instrumentation and fusion for degenerative scoliosis of the lumbar spine.

The authors report a homogeneously investigated and surgically treated series of 40 patients with degenerative scoliosis of the lumbar spine. The series included 22 females and 18 males with a mean age of 62.8 years. The clinical presentation, the diagnostic work-up, the indication for surgery, the surgical techniques and results are reported. Final evaluation was possible in 30 patients at a mean period of observation of 59.5 months. Following a very precise diagnostic and therapeutic protocol excellent, good and satisfactory surgical results were obtained in 13 (43.3%), 16 (53.3%) and 1 (3.3%) patients, respectively. While scoliosis was converted from a mean preoperative Cobb angle of 18.7 degrees to 7.6 degrees mean pre-operative lumbar lordosis was slightly augmented from 37 degrees to 41.5 degrees. The results suggest that maintainance or correction of lumbar lordosis is more important than the conversion of the scoliotic deformity which is probably treated sufficiently by partial correction and stabilization. Observation over time indicates that the degenerative cascade evolves despite internal fixation and fusion in the majority of the patients until a stable state is reached. This stable state is probably rather the result of ankylosis of the facet joints than the effect of posterolateral fusion.

Adult↗
PubMed1999

Surgically controlled, transpedicular methyl methacrylate vertebroplasty with fluoroscopic guidance.

The authors report a series of 13 patients with osteoporotic vertebral fractures treated by transpedicular vertebroplasty. Because of a neurological complication due to posterior leakage of acrylic cement the classical percutaneous approach was converted to an open surgical procedure. The latter allows direct visual control of neural structures and immediate removal of spilled cement, thus eliminating the danger of compressive, chemical and thermal effects of methyl methacrylate on neural elements. By use of this elegant technique primary stability of fractured vertebras is obtained leading to prompt pain relief in all patients. Surgically controlled vertebroplasty can be used in conjunction with internal fixation. By having studied the different ways of cement escape in their patients, the authors are convinced that surgically controlled vertebroplasty is safer than percutaneous vertebroplasty.

Aged↗
PubMed1998

Surgical results after soft system stabilization of the lumbar spine in degenerative disc disease--long-term results.

After having reported preliminary results of soft system stabilization according to Graf in a series of 27 patients with degenerative disc disease of the lumbar spine in early 1995 the authors report long term clinical and radiological results of this patient series (n = 25). At a mean period of postoperative observation of 50 months excellent, good, satisfactory, moderate and poor results were obtained in 62, 9%, 11, 1% and 11, 1%, 7, 4% and 7, 4% of the patients, respectively. The well-known phenomenon of loss of disc height at the level of posterolateral fusion and instrumentation as well as overcharge of adjacent segments were not observed after soft system stabilization. Regional as well as global lumbar lordosis were maintained and, although statistically not significant, an increase of intervertebral distance was observed in adjacent segments in flexion of the lumbar spine. These phenomena might represent pressurization of instrumented as well as adjacent discs after the insertion of ligament prostheses. It is the impression of the authors, that the Graf technique leads to good surgical results in degenerative disc disease with destabilization of lumbar motion segment(s) if the following criteria are strictly respected: 1. No or only mild arthrotic changes of the facet joints 2. Preferably minor disc degeneration/only mild loss of intervertebral distance. 3. Well trained low back muscles and 4. A clear-cut, repeatedly demonstrated pain-relief on trial anaesthesia of the corresponding articular nerves and while wearing a probatory jacket.

Adolescent↗
PubMed1995

Soft system stabilization of the lumbar spine as an alternative surgical modality to lumbar arthrodesis in the facet syndrome. Preliminary results.

The authors present preliminary results in a series of 27 patients with a lumbar and/or lumbosacral facet syndrome operated on by use of the soft-system-Stabilization (SSS) according to Graf. Attention is paid to the correct selection of patients for this surgical technique. Excellent, good, satisfactory, moderate, and poor results were obtained in 19 (70%), 2 (7.5%), 5 (18.5%), 1 (3.5%), and 0 instances, respectively. The authors think that a Graf-procedure may be indicated in young to middle-aged patients with a lumbar and/or lumbosacral facet syndrome with 1.) no arthrotic changes of the facet joints, 2.) a still intact disc and/or only mild loss of intervertebral distance, 3.) well trained low-back muscles, and 4.) a clear-cut pain relief on test-anaesthesia of articular nerves and trial immobilization in a plastic jacket.

Adolescent↗
PubMed1994

The lumbar and lumbosacral facet-syndrome. Diagnostic measures, surgical treatment and results in 119 patients.

The authors present their diagnostic and therapeutic protocol as well as the surgical outcome in a series of 119 patients with the lumbar facet syndrome. By use of different surgical techniques such as translaminar screw fixation (n = 56), Louis plate fixation (n = 36), Cotrel-Dubousset instrumentation (n = 11) and soft system stabilization according to Graf (n = 14) excellent, good, satisfactory, moderate and poor results were obtained in 78 (67%), 20 (17%), 14 (12%), 4 (3%), and 1 (1%) instances, respectively.

Adolescent↗
PubMed1993

Failed back surgery syndrome. Part II: Surgical techniques, implant choice, and operative results in 171 patients with instability of the lumbar spine.

171 patients with an instability-related failed back surgery syndrome underwent internal fixation. The operative indication was based on specific diagnostic procedures such as anaesthesia of articular nerves and the trial external immobilization in a plaster jacket. Taking account of the different types of hypermobility/instability of the lumbar spine, different spinal implants were used leading to excellent, good, satisfactory, moderate and poor results in 87 (53%), 42 (26%), 23 (14%), 9 (6%) and 2 (1%) patients, respectively.

Adult↗
PubMed1993

Failed back surgery syndrome. Part I: Analysis of the clinical presentation and results of testing procedures for instability of the lumbar spine in 171 patients.

The clinical presentation and diagnostic approach in 171 patients with a failed back surgery syndrome is presented and analyzed with respect to the mode of the primary discectomy-approach and type of resulting instability as well as results of internal fixation. The clinical picture and physical signs are quite distinct but the indication for internal fixation is only obvious in the presence of positive results of additional testing procedures such as the anaesthesia of articular nerves and trial immobilisation in a plaster jacket. Different types of instability of the lumbar spine occur in relation to the mode of the primary and/or secondary discectomy-approach(es). By application of this diagnostic protocol excellent, good, satisfactory, moderate and poor results were obtained in 87 (53%), 42 (26%), 23 (14%), 9 (6%), and 2 (1%) patients, respectively (final evaluation was possible in 163 patients).

Adult↗
PubMed1993

Surgical management of neurogenic claudication in 100 patients with lumbar spinal stenosis due to degenerative spondylolisthesis.

100 consecutive patients with neurogenic claudication due to segmental spinal stenosis in degenerative spondylolisthesis have been analyzed prospectively with respect to their clinical presentation, radiological and intra-operative findings, operative techniques and surgical results. By including 6 patients who had to be operated upon again overall results were excellent in 91, good in 4, satisfactory and moderate in 2, respectively, and poor in 1 patient (mean period of postoperative observation: 2.9 years). Three different techniques of spinal instrumentation are evaluated with respect to the surgical results. After microsurgical decompression of the neural elements 38 patients were fixed using the translaminar screw fixation method according to Magerl (re-operation necessary in 5), in 9 patients spondylodesis was achieved by the plate fixation method according to Louis (re-operation necessary in 1) and in 53 patients (as well as in the 6 patients who had to be re-operated on) primary Cotrel-Dubousset instrumentation was used. The best surgical results were obtained by laminectomy and Cotrel-Dubousset fixation. Instrumentation of more than 1 motion segment was restricted to patients with additional scoliosis or severe degenerative changes of the lumbar spine.

Aged↗
PubMed1991

"Isthmic" spondylolisthesis--an analysis of the clinical and radiological presentation in relation to intraoperative findings and surgical results in 72 consecutive cases.

72 patients with isthmic spondylolisthesis have been analyzed prospectively with respect to their clinical presentation, radiological and intraoperative findings, operative techniques and surgical results. Excellent, good and satisfactory results have been obtained in 59 (82%), 10 (14%) and 3 patients (4%), respectively, by use of microsurgical techniques in combination with Louis-plate-fixation in Grade I and double arthrodesis/Cotrel-Dubousset-instrumentation in Grade II spondylolisthesis.

Adolescent↗
PubMed1991

Atlanto-axial fusion with transarticular screw fixation.

We reviewed 161 patients, from four centres in Switzerland, who had undergone posterior fusion of the upper cervical spine with transarticular screw fixation of the atlanto-axial joints. They were followed up for a mean 24.6 months. The vertebral artery and the medulla escaped injury and only 5.9% of the complications were directly related to the screws. The rate of pseudarthrosis was 0.6%.

Adolescent↗
PubMed1989

Diagnostic approach in instability and irritative state of a "lumbar motion segment" following disc surgery--failed back surgery syndrome.

A diagnostic protocol for patients with suspected instability and irritative state of a "lumbar motion segment" following lumbar disc surgery is presented and the results of internal fixation are analyzed. In this group of patients the clinical picture and physical signs may be quite distinct and suggestive of instability and irritation of a "lumbar motion segment", however, in isolation, they do not allow to decide upon surgery. Radiological studies favour a decision for surgery only in cases with an obvious instability of a "motion segment". Anaesthethizing the articular nerves permits localization of the irritable segment and non-surgical therapeutic decisions (thermocoagulation) can only be taken in cases of an isolated facet-syndrome when instability has been ruled out. The trial plaster jacket holds the most important position with respect to the indication for internal fixation as demonstrated by the conformity of the results of the plaster jacket and the results of surgery. After internal stabilization excellent, good, satisfactory and moderate results were obtained in 20, 3, 1 and 1 patients, respectively.

Anesthesia, Spinal↗
PubMed1989

Translaminar screw fixation in lumbar spine pathology. Technical note.

Two technical variations of the method of translaminar screw fixation for unstable lumbar and lumbosacral segments are presented. Distraction-arthrodesis with intraarticular bone grafts allows definitive enlargement of narrowed foramina with consecutive root decompression as well as repositioning and intracanalicular decompression in cases of instability after lumbar disc surgery and in degenerative spondylolisthesis. Reconstruction of a hemilamina after hemilaminectomy and facet reduction allows reconstitution of the spinal canal and its posterior parts as well as direct treatment of intraforaminal pathology.

Adult↗
PubMed1989

Immunocytochemical evidence of progesterone receptors in human meningiomas.

The presence of progesterone receptors in meningioma tissue is demonstrated by use of highly specific monoclonal antibodies against the rabbit progesterone receptors which cross-react with human progesterone receptors in breast cancer cells, thus giving evidence of the existence of genuine progesterone receptors in human meningiomas.

Antibodies, Monoclonal↗
PubMed1989

Endocrine manipulation of meningiomas with medroxyprogesterone acetate. Effect of MPA on growth of primary meningioma cells in monolayer tissue culture.

Intracranial meningiomas from patients treated with medroxyprogesterone acetate as well as from untreated patients were studied in monolayer tissue culture with trials of in vitro hormonal modulation with medroxyprogesterone acetate. The following conclusions were drawn from investigations which comprise 37 cell culture assays: (a) tissue cultures of meningiomas inherit the disadvantages of loss of the progesterone receptor and frequent transformation to cells resembling fibroblasts after three to four passages. For these reasons, drug testing as well as the establishment of cell cultures that exhibit the characteristics of meningioma are impeded; (b) the progesterone receptor-content of the solid tumors does not reflect the response to medroxyprogesterone acetate-therapy in vitro; (c) medroxyprogesterone acetate-pretreated meningiomas showed sufficient in vitro growth in 38%, and untreated meningiomas grew well in 56% of the cases; (d) medroxyprogesterone acetate-induced inhibition or delay of growth was observed in 35%. These findings have resulted in criticism with respect to the value of meningioma tissue cultures for trials of hormonal manipulation and it is thought that another method, which consists of immunostaining of cycling cells, and has been tested in another study, may be superior to cell culture assays with respect to evaluation of the effect of hormonotherapy in meningiomas. Medroxyprogesterone acetate holds an interesting position because it reduces cell growth in some meningiomas in vitro.

Antigens, Surface↗