Biomedical subjects

C Hopf

Publications and source records attributed to C Hopf.

At least 73 records · Page 4Linked to original sources

PubMedDate not supplied

[Indication, biomechanics and early results of artificial disk replacement].

AIM: Judgment of factors concerning the indication for the implantation of an artificial disc endoprosthesis, the rating of this operation and biomechanical considerations. METHOD: Presentation of the indication and the value of a new operative concept in comparison to a so-called dynamic stabilization procedure (Dynesys' method). Indications for the operation are: unsuccessful, orthopedic conservative treatment for > 6 months, segmental pain, age < 45 years, evidence of an MRI demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures such as facet joint infiltration and discography. RESULTS: In an earlier investigation the efficacy of the Link method was demonstrated as shown by the reduction of the analgesic use, the angle of the lumbar lordosis (L1-S1) increased from 35.6 degrees to 42.6 degrees (20.2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). The new investigation using the Aesculap endoprosthesis resulted in a change of the angle of lumbar lordosis from 35.4 degrees to 45.4 degrees (25.4 %) and a change of the segmental angle from 17.3 degrees to 29.1 degrees (57.6 %). This method is a real endoprosthetic instrumentation in the field of spinal surgery. CONCLUSION: In younger patients with mono- or bisegmental disc degeneration there is an indication for the implantation of a disc endoprosthesis. A facet joint arthrosis and an age over 45 years are contraindications for the operation. The indication in patients with a classic failed back surgery syndrome is still unclear, the improvement of the instrumentation and a further adaptation of the systems to the known biomechanics of the lumbar spine are mandatory as is an intensive discussion of the operative procedure in the case of revision operations. The Dynesys method, with the inherent danger of segmental kyphozitation, a published, significant revision quota combined with a reduction of motility, does not fulfill this criterion.

Adult↗

PubMedDate not supplied

[Extracorporeal shockwave therapy of radiohumeral epicondylopathy-- an alternative treatment concept].

During the last 2 years 75 patients referred to our hospital for operation of a persistent tennis elbow were followed prospectively after receiving low-energetic extracorporal shock wave therapy. 3 times in weekly intervals all patients received 1000 impulses of the energy density 0.06 mJ/mm2. Follow-ups were performed at 3, 6, 12, 24 weeks. Statistical analysis showed significant improvement both of subjective and objective criteria. 41 patients became painfree. Only 7 patients decided to have an operation after the 24-weeks-follow-up. Ambulatory shock wave therapy is a considerable alternative before surgical intervention in chronic tennis elbow.

Electromagnetic Fields↗

PubMedDate not supplied

[Multi-segment ventral stabilization of the lumbar spine: a comparative biomechanical study].

The stability provided by three anterior spinal fixation devices (VDS, TSRH, CDH) designed for multisegmental instrumentation have been studied in an in-vitro model using L1-L5 sections of six human cadaveric spines for each instrumentation. Three-dimensional measurement of rotation and translation for the intact and instrumented spine under physiological loads in flexion/extension, lateral bending, and axial rotation were determined. After measuring the intact spine the destabilization was performed by complete intersection of the intervertebral disc, all spines were instrumented for 3 segments. TSRH was found to be significantly (p < 0.05) higher in stiffness in flexion/extension and torsion than VDS. In bending there was no statistical difference. In all tests CDH was significantly more stable than VDS. In flexion/extension it proved higher in stiffness than TSRH, no statistical difference was observed in bending and rotation.

Biomechanical Phenomena↗

PubMedDate not supplied

[Transpedicular lumbar spondylodesis in elderly patients].

70 patients older than 50 years (mean age: 60.2 years) underwent a CD-spondylodesis from 1987 to 1991 for degenerative changes of the lumbar spine, and were followed for 2 years. 88.2% improved, but only 47.1% showed a good-to-excellent result. Patients with fair and poor outcomes had had significantly more operations on the lumbar spine (p < 0.001), had a greater extent of preoperative lumbar kyphosis (p < 0.05), motor weakness (p < 0.05), had less vertebral slips (p < 0.01), had less posterior distraction postoperatively (p < 0.001), and had a greater extent of postoperative motor weakness compared to patients with good-to-excellent outcomes. Age, sex, duration of back/leg pain, taking of analgetic drugs, preoperative pain status, profession, range of walking, time of operation, number of fused segments, blood loss, blood transfusion, postoperative profile of the spine did not show any significant influence upon clinical results. Already at 6-months-follow-up there was significant difference of the clinical outcome (p < 0.001), making improvement of a then fair or poor result unlikely.

Aged↗

PubMedDate not supplied

[CDH--preliminary report on a primary stable ventral lumbar spine instrumentation].

CDH-instrumentation was developed by the principles of an improved stability in ventral operation procedure and by the possibility of treating all anterior spinal diseases. The implantation of anterior plates and drawers, the use of rods fixed within the implant in non-parallel directions thus automatically providing for a locking mechanism against displacements, the prevention of dislocation of the cancellous bone screws and the DDT-principle were further requirements. The spine can be corrected according to the three-dimensional anatomy by distraction-, compression and rotational forces, a postoperative external support is unnecessary. After the application of the method in 50 patients (mono- and multisegmental) the excellent stability could be proved.

Adolescent↗

PubMedDate not supplied

[Significance of dorsal decompression and instrumentation in the treatment of spinal malignancies].

From 1986 to 1990 50 patients with increasing spinal instability due to pathologic fractures of one or more vertebrae were operated in the Orthopedic Department of Mainz University Hospital. In the course of 57 operations anterior decompression and stabilization were performed 3 times, whereas dorsal spondylodesis was done with Cotrel-Dubousset's instrumentation (CDI) 32 times, with Luque's 7 times and with Harrington's 1 time; a combination of CDI and Luque was chosen in 2 cases, a combination of Harrington and Luque in 1 case. 3 times a single-stage combination and 4 times a two-stage combination of ventral and dorsal stabilization was used. The application of the CDI required no postoperative external support. 35 patients suffered from major neurologic deficits preoperatively--among them 11 from a complete and 6 from an incomplete paraparesis--which made spinal cord decompression necessary in advance of the dorsal stabilization. Of these, 16 improved significantly; however, deterioration of the neurologic status occurred in 4 cases with a paraparesis in 3 of them. Survival time postoperatively was approximately 13 months in 27 patients. 9 of these died within half a year after the operative intervention. Failure of fixation as a result of tumor lesion was found in 2 cases of CDI procedure and in 1 case of the Harrington instrumentation. All required a revisional operation. 3 patients developed a radiologic lysis of methylmethacrylate implants fixed by an anterior procedure. Posterior decompression and stabilization render possible resolution of spine pain as well as restoration of mobility until a few days before exitus letalis without restricting adjuvant radio- or chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMedDate not supplied

[High-energy extracorporeal shock-wave therapy (ESWT) in the treatment of pseudarthrosis].

PROBLEM: The success rate of high-energy extracorporal shock wave therapy in the treatment of non-unions in comparison to the "golden standard" surgery is still unclear. METHOD: In a prospective study, 3000 impulses with an energy density of 0.6 mJ/mm2 were applied with an experimental device to the pseudarthrosis in 52 patients. RESULTS: The mean duration of pseudarthrosis was 13 months. A mean of 2.5 surgical interventions had already been performed. Bony union was achieved in 52% of our patients after an average of 3.3 months. Failures especially were found in the atrophic type of pseudarthrosis as well as in congenital bone disorders like fibrous dysplasia or osteogenesis imperfecta. No serious complications were observed. CONCLUSIONS: Even after numerous surgical interventions high-energy extracorporal shock wave therapy as a noninvasive method for the treatment of bony non-unions showed a fair success rate. A higher success rate can be expected by strict selection criteria.

Adolescent↗

PubMedDate not supplied

[The problem of comparability of results of the treatment of congenital hip dislocation--exemplified by the Severin scheme and the classification system of the Work Group Hip Dysplasia].

The comparison of the results obtained by conservative or operative treatment of hip dysplasia shows that the consideration of absolute roentgenologic hip parameters is of little use. Classification principles for numerous hip parameters have been developed for this reason by Tönnis. In the Angloamerican and Scandinavian countries, on the other hand, it is predominantly the Severin classification that is employed for an evaluation of the methods of treatment. We examined in our study the differences in the evaluation of the results obtained in 117 hip joints treated by pelvic osteotomy according to Salter by application of the AKH and the Severin classification scheme. There were evident differences in all groups of these classifications. In the application of the Severin scheme the groups I, II and III contained 9.5% less, 24.8% more, and 18.8% less hip joints, respectively than in the respective groups of the Tönnis classification. In the groups IV, V and VI of the Severin classification there were altogether 3.5% less hip joints than in the respective groups of the Tönnis classification. Our study thus showed that a comparison of the operative results of hip dysplasia as presented in the Angloamerican and Scandinavian literature and those presented in the German literature is not possible. We conclude from this result that an evaluation according to a unified classification scheme would be most desirable.

Adolescent↗

PubMedDate not supplied

[Significance of exact lateral roentgen documentation in Meyerding's grading of spondylolistheses].

The treatment of spondylolisthesis-in particular the indication of operation-is based on clinical symptoms as well as radiological criteria. For radiological techniques, the lateral profile, especially in function tests, is of importance. As a basic requirement the grade of Meyerding should be evaluated on x-ray in the exact lateral profile. We have observed, that even a slight rotation of the spine leads to misjudging of the real degree of vertebral dislocation. In 30 patients with spondylolisthesis of the lumbar spine the x-rays, made in exact lateral position, were compared with x-rays in 10 degrees rotation of the spine. On the average we measured an increase of vertebral dislocation of 3-4 mm. The increase was independent of the grade of Meyerding or the level of spondylolisthesis. The results could be verified by a spine of a human corpse.

Adolescent↗

PubMedDate not supplied

[The surgical treatment of scoliosis of various etiology. Results after 150 operations using CD-instrumentation with reference to the effects of the instrumentation on the sagittal spinal profile].

At the Orthopaedic University Hospital of Mainz more than 150 patients were treated surgically according to Cotrel and Dubousset procedure. By means of this operation average corrections of the curves of 54.8% to 64.6% could be achieved in the first 150 patients, depending of the localization of the curve. Operative procedure, duration of operation and blood loss are adequate to known procedures, the stability of the method is better than in other known methods. The change of the postoperative sagittal profile demonstrates the influence of the operation in cases of hypokyphosis in the thoracic and hypolordosis in the lumbar spine.

Adolescent↗

PubMedDate not supplied

[Diagnosis and therapy of osteoid osteoma of the vertebral lamina--a literature review and personal experiences].

Osteoid-osteoma is a benign tumor which is rarely situated in the spine. Five patients with osteoid-osteoma of the lamina treated surgically at the Department of Orthopaedic Surgery of the University of Mainz between november 1990 and january 1992 are reviewed. The combination of pain, painful reactive scoliotic position of the spine or torticollis, hot spot in scintigraphy and nidus in computer tomography is the typical feature of the tumor. The average delay between the onset of symptoms and definitive diagnosis was 10 months. In all cases the tumor was completely removed. In one case with localization in the axis in a 15 year old boy a laminoplastic was performed. The average follow-up was 16 months. Surgical treatment afforded immediate relief of pain and an early return to full spinal mobility. In case of persisting backache especially in children or young adults osteoid-osteoma of the spine must be suspected. The scintigraphy represents the most sensitive method of diagnosis in the early stage.

Adult↗

PubMedDate not supplied

[Multi-segmental fusion of scoliosis in Duchenne's muscular dystrophy].

Operations in scoliosis in patients suffering from an advanced stage of Duchenne muscular dystrophy are associated with a higher risk due to the extent of the curves, the respiratory insufficiency and frequent cardiomyopathia. Progressive scolioses in 20 wheelchair patients with an age between 10.5-18.3 years (mean 14.6 years) were treated by CDI. The mean preoperative angle in this group was 70.6 degrees, the postoperative angle 31.2 degrees (mean correction 39.4 degrees or 55.8%). The preoperative lordosis of the lumbar spine (mean angle 4.1 degrees) was corrected to 17.8 degrees postoperatively. The average intraoperative blood loss (2300 ccm) was evident more compared with idiopathic scoliosis. One neurologic complication (postoperative disturbance of bladder function) was observed. Nowadays early surgical correction and stabilization (Cobb angle > 20 degrees) has to be recommended as the treatment of choice for scolioses in Duchenne muscular dystrophy using multisegmental instrumentation methods to enable rapid mobilisation and a postoperative care without brace or cast. This conception allows a prophylactic operation including the following targets: prolongation of life expectancy, improvement of sitting position and prevention of rapid deterioration of lung function including assisted mechanical ventilation in late stages.

Adolescent↗

PubMedDate not supplied

[Use of the tumor prosthesis in secondary neoplastic destruction of the proximal end of the femur].

Total hip arthroplasty was performed with PMMA-augmented tumor prostheses in 42 individuals suffering from metastatic destruction of the proximal end of the femur at the Orthopedic University Hospital Mainz from 1980 to 1992. Neoplastic lesions had been triggered by carcinomas of the breast in 25 female patients. 24 of our patients presented with pathologic fractures. In all patients capable of walking preoperatively early mobilization could be attained by total hip arthroplasty. Pain relief was achieved in each patient. Resection of the major trochanter and, partially, of the pelvitrochanteric muscle sleeve entailed luxation of the prosthesis six times in 5 individuals during the first postoperative two months; closed reduction was practicable in all of them. Postoperative survival time amounted to an average of 10.5 months. Leg length and hip function were successfully re-established by implanting tumor prostheses after resection of the proximal part of the femur.

Adult↗

PubMedDate not supplied

[Progression of Paget's disease of the spine 10 years following posterolateral spondylodesis].

M. Paget is regarded as a disease confined to the bone. Its chief characteristics are increased bone metabolism with accelerated bone reduction and precipitate bone reconstruction. One of the most common sites of the disease is the lumbar spine. Encroachment of Paget's disease from the third lumbar body to the neighbouring spinal structures is described 10 years after a lumbar spondylodesis.

Follow-Up Studies↗

PubMedDate not supplied

[Indications and results of surgical treatment of neuromuscular scoliosis].

The results of the operative treatment of 44 patients suffering from a neuromuscular scoliosis are presented. Only multisegmental procedures - also in combination with anterior methods - should be used to avoid a postoperative care with cast or brace. By means of the operation an average correction of the curves of 50.7% was achieved. The preoperative mean angle was 75.1 degrees, postoperatively a mean angle of 37.0 degrees (mean correction of 38.1 degrees) was determined. The preoperative angle, the duration of the operations, the blood loss and the quantity of the complications are higher than in idiopathic scolioses. As a result of the known tendency of deterioration in neuromuscular scolioses, the members of the Arbeitskreis Skoliose of the German Orthopaedic Society (DGOT) recommend an early operation (in progressing curves over 20 degrees) in patients suffering from a muscular dystrophy Duchenne.

Adolescent↗

PubMedDate not supplied

[Recommendations for participation in sports by patients with idiopathic scoliosis].

Presented is the recommendation of the "Arbeitskreis Skoliose" of the DGOT concerning the sporting activities for juvenile patients suffering from an idiopathic scoliosis. The main points of this concept are the desirable active participation in school sport activities and the ascertainment that restrictions are not necessary in scolioses up to 21 degrees. A special recommendation for operated patients predicates the begin of sport activities after ohne year postoperatively. The kind of sport must be recommended by the surgeon, high-performance sports cannot be tolerated in those patients. Precondition for these recommendations are regularly physical examinations by the orthopedic physician and standardized x-rays in standing position.

Adolescent↗

PubMedDate not supplied

[Results of the surgical treatment of spondylolisthesis and of lumbar and sacral vertebrae which underwent spondylodesis].

Presented are the results after the surgical treatment (CDI) of 25 patients suffering from spondylolisthesis and of 25 patients with a lumbar or a sacral spondylodesis. The mean follow up reaches from 8.4 (spondylolisthesis) to 16.6 months (lumbar and sacral spondylodesis). 15 (60%) of the patients with spondylolisthesis showed an excellent or good result, in 3 (12%) the result was unsatisfactory. Only 7 of the patients of the second group were without further complaints, in 6 an amelioration of pain relief could be reached. The complications demonstrate the fault of the instrumentation in the beginning. After the development of a new screw the monosegmental fusion with CDI can be achieved in spondylolisthesis with a slipping to 70%, in more severe spondylolisthesis bisegmental fusion is necessary. The results in lumbar and sacral spondylodesis demonstrate that the operation should be only performed when all other methods have been unsuccessful.

Female↗

PubMedDate not supplied

[Comparative animal experiments on tissue compatibility and measurement of radioactivity of various roentgen contrast media].

In a comparative study the tissue reaction of several X-ray contrast materials was examined by subcutaneous and intraperitoneal application on rats. There were tested Bariumsulphate (BaSO4) and three Zircondioxyde (ZrO2) samples of several manufactures (cubic and monocline ZrO2-Feldmühle; Optipur-Merck). In the histologic evaluation no inflammatory signs could be seen. In case of BaSO4 the tissue reaction was more distinct than in the ZrO2 samples. Within the tested ZrO2 samples the differences were small; the cubic ZrO2 showed the slightest, the monocline one the relatively strongest cellular reaction. We also measured the radioactive emission by the contrast media. Here the monocline and--first of all--the cubic ZrO2 showed an alarming radioactive emission (radium 3000-11,500 Bq/kg). Only the Optipur (Merck) was free of radiation and can so be recommended for human implantation. Also the BaSO4 had no measurable radioactive Emission. Therefore only these two X-ray contrast media can be recommended for human implantation.

Animals↗