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Biomedical subjects

C Hopf

Publications and source records attributed to C Hopf.

At least 55 records · Page 3Linked to original sources
PubMed1993

Development of scoliosis in myelomeningocele. Differences in the history caused by idiopathic pattern.

The natural history of scoliosis in the literature concerning the idiopathic and neuromuscular scoliosis in myelomeningocele patients (MMC) are compared to our own results in 12 patients with MMC and 89 patients operated because of an idiopathic scoliosis. According to known experiences the natural history of scoliosis in MMC is progression even after the end of growth. The chance of developing a scoliosis increases with the patients, age and the level of the lesion. The higher the level of paralysis the more common is a spinal deformity. In literature the progression rate of MMC scoliosis is 2.5-3.5 degrees per year, with the idiopathic pattern 0.5-0.65 degrees per year after end of growth. Our own results of surgically treated patients show a rate of progression of 6.2 degrees per year in MMC. The surgical treatment must start before a severe spinal deformity has developed because of the higher rate of operative complications.

Adolescent↗
PubMed1993

Metastatic spinal cord compression--options for surgical treatment.

Fourty-three cases with metastatic spinal cord compression were reviewed post-operatively to clarify the usefulness of the procedures concerning restoration of neurological function, and pain relief. Only patients with pathological spinal instability and neurological sequelae were included. Posterior decompression and stabilization was performed in all but six patients. All but four patients (91%) reported decrease of pain symptoms. Amelioration of neurological function was achieved in 58%. Re-establishment of walking ability was obtained in 57%. Post-surgery life expectancy averaged 11 months. In patients with widespread metastatic disease and/or multi-level instability of the spine restriction to palliative dorsal procedures is sensible. Post-operative ancillary treatment is necessary.

Adult↗
PubMed1993

Decompression/stabilization of the metastatic spine. Cotrel-Dubousset-Instrumentation in 50 patients.

50 patients with metastatic disease of the spine underwent dorsal decompression and stabilization with the Cotrel-Dubousset-Instrumentation from 1987 to 1991. Indications for surgical treatment were neurologic deficit, spinal instability, and/or pain resistant to medical or radiation treatment. No external orthotics were used postoperatively. Pain was relieved dramatically in 45 patients. Among 25 patients suffering from neurologic deficit preoperatively, 13 improved, 15 remained unchanged, whereas 2 developed an incomplete, transient paraplegia. 15 (7) patients were alive after 1 (2) years. Postoperative complications were frequent, but there were only 2 failures of the stabilization device requiring reoperation.

Adult↗
PubMed1992

The influence of lateral release on patello-femoral joint loading in knee arthroplasty. An experimental in vitro study.

Eight fresh, cadaveric knees have been fitted with four different total knee cemented prostheses. Loading forces at the bone implant fixation interface of the patella component have been measured in a knee joint testing rig by four miniaturized force transducers, before and after a lateral release of the patellar retinaculum. The lateral release resulted in a significant local force reduction in the lateral and/or proximal quadrant of the patella resection plane depending on the knee flexion angle, quadriceps tensile force direction, and the patellar prosthesis design.

Humans↗
PubMed1992

The effect of cement fixation on initial micromotion of the femoral component in condylar knee replacement.

Four fresh, cadaveric specimens were fitted with total knee replacements and mounted on a knee joint loading and measuring rig. Femoral component micromotion in the sagittal plane was measured with a transducer during flexion and extension of the specimen. Various condylar designs were used without and with cement. Movement followed a characteristic curve pattern and was less with cement fixation particularly for bone of low trabecular strength as determined by bone sample tests for stiffness. Cement fixation appears to be superior to cementless fixation.

Bone Cements↗
PubMed1991

[Postoperative analgesia following spondylodesis using a peridural catheter placed during surgery. Results of a pilot study].

For the treatment of postoperative (p.o.) pain following vertebral surgery, systemic analgesics are frequently used in high doses with a variety of side effects. It was the aim of this study to investigate p.o. epidural catheter analgesia in 20 patients following surgical correction of scoliosis using the Cotrel and Dubousset technique. METHODS. The patients received balanced general anesthesia with fentanyl and isoflurane. At the end of the operation, before closing the fascia, an epidural catheter was placed by the orthopedic surgeon. After extubation and following evaluation of the motor function of all extremities. 6-10 ml bupivacaine 0.25% was injected into the epidural catheter followed by continuous administration of 0.25% bupivacaine 4-8 ml/h. Analgesic level and hemodynamic parameters were monitored. Pain was measured by the visual analogue scale. If analgesia was not sufficient, the patients received tramadol or piritramide intravenously. RESULTS. In 11 of 20 patients epidural analgesia was rated adequate; 5 needed additional systemic analgesics, and in 4 effective analgesia was not achieved with either epidural analgesia or systemic opioids. No complications were observed. DISCUSSION. The pilot study documented that epidural analgesia using an intraoperatively placed epidural catheter can be used for p.o. pain relief after vertebral surgery using the Cotrel and Dubousset technique. Additional studies will compare the method described to other pain-relieving procedures.

Adolescent↗
PubMed1991

[The importance and form of the collar in hip joint endoprosthesis. Theoretical analysis and biomechanical study].

Flat contact of the collar of the stem with the resection area of the femur in total hip replacement can often not be achieved even when the operation technique is very precise. Uneven bone patches or deviations in the resection angle lead to points of contact. If this contact area is localized to the lateral part of the collar, considerable varus torque acts on the prosthesis stem. By a simple modification, removal of the lateral area of the collar, medical bone - collar contact is achieved. It is independent from deviations in the operative procedure. In biomechanical experiments, drastic reduction in harmful torque was demonstrated by this modification. Thus, more "physiological" force transmission from the prosthesis to the bone can be expected.

Biomechanical Phenomena↗
PubMed1990

Operative therapy in metastases and primary tumors of the spine.

Benign and primary malignant tumors of the spine require a ventral procedure to remove the tumor and to stabilize the spine. Experience in the last years has shown that sole laminectomy in children can no longer be recommended. An instrumentation of the spine to prevent kyphosis must be performed. The rate of pseudarthrosis was of course, high when the kyphosis was treated by an exclusive dorsal instrumentation. In patients with severe kyphosis a combined procedure with ventral and dorsal operation is necessary. Solitary metastases of cancer of the prostate, breast, and the thyroid gland show a better prognosis than metastases of cancer of the lung or the stomach. Thus metastases of the first group which also show a dependency on hormones, should be operated on by a ventral procedure, independent of the location of the tumor. In cases of multiple metastases and bad condition of the patient a ventral operation is not indicated. In these cases, a dorsal procedure with decompression and stabilization allows mobility of the patients until only few days before death. An implantation of instrumentations that include a transpedicular screwing can result in spreading of the tumor to the neighboring vertebrae. Therefore, this kind of operation should be the "ultima ratio".

Adolescent↗
PubMed1990

[Comparative studies on the radioactivity of bone cements containing x-ray contrast media and of the contrast media].

Various PMMA bone cements containing zirconium oxide (ZrO2) as an X-ray contrast medium and zirconium oxides of several manufacturers were tested for their radioactivity by means of a gamma spectrometer. All the bone cements tested (Implast, Palacos R, and Sulfix-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. The examination of various zirconium oxides showed some high radioactive emissions. The risk of radiation-induced cancer seems to be small, because the cements are normally implanted in humans older than 60 years. In view of the fact that these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be replaced by high-purity radiation-free zirconium oxide or barium sulphate as soon as possible.

Bone Cements↗
PubMed1990

[Indications for and results of the CD procedure (Cotrel Dubousset) in surgical scoliosis therapy].

At the orthopaedic University Hospitals of Mainz and Münster more than 200 patients were treated surgically according Cotrel and Dubousset procedure. By means of this operation average corrections of the curves of 50.7% to 56.7% could be reached in the first 150 patients, depending of the localisation of the curve. Operative procedure, duration of operation and blood loss are adequate to known procedures. Pre- and postoperative CT's in 24 patients with idiopathic scolioses showed a mean correction of the rotation angle in the apex vertebra of 28.5% in relation to the anterior midline of the body and of 23.8% in relation to the sagittal plane. The best corrections could be observed in lumbar curves and in the lumbar curves of double major scoliosis. A postoperative therapy with cast or braces is not necessary.

Adolescent↗
PubMed1989

[The progression of untreated idiopathic scoliosis in the x-ray image].

The natural history of scoliosis, or lateral curvature of the spine, was followed up in 135 patients (111 girls, 24 boys) for a total average period of 52.4 months. We observed patients with a curvature of between 5 degrees and 30 degrees none of whom had been treated specifically as orthotics or with electrical stimulation or by surgery. Two groups of patients with progressive curvature were differentiated: 1) in 62.2% of the patients the curvature progressed by more than 5 degrees during the entire observation period; 2) in 36% of the patients we found an increase in curvature by more than 5 degrees within one year. Another result of our study was that idiopathic scoliosis is particularly dangerous in young patients with a "0" Risser sign. Thoracic curvatures and double major curvatures were more liable to progress than lumbar and thoracolumbar curvatures. Even a small angle of curvature in young patients must be taken seriously.

Adolescent↗
PubMed1989

[A computed tomographic analysis of vertebral rotation before and after surgical correction of idiopathic scoliosis].

Preoperative and postoperative computer tomographs in 24 patients suffering from idiopathic scolioses who were treated by CD (Cotrel-Dubousset) surgery, showed a mean correction of the rotatory angle in the apex vertebra amounting to 28.5% in relation to the anterior midline of the body, and 23.8% in relation to the sagittal plane. Best results were seen in lumbar curves and in the lumbar curves of double major curves. In thoracic curves only minor corrections were observed. CD instrumentation is the first dorsal procedure that allows a three-dimensional correction of the scoliotic spine.

Adolescent↗
PubMedDate not supplied

Shoulder function after extracorporal shock wave therapy for calcific tendinitis.

We report a controlled, prospective study that explored the effect of extracorporal shock waves of low- versus high-energy density in patients with chronic shoulder pain and calcific tendinitis. We assigned at random 100 patients who had had calcific tendinitis for more than 12 months to 2 groups to receive shock wave therapy either of a low- or high-energy density. Group 1 received 1500 impulses of 0.06 mJ/mm2, whereas group 2 received 1500 impulses of 0.28 mJ/mm2. Unlike group 1, in which the shock wave application could be performed without local anesthesia, all patients in group 2 required brachial plexus anesthesia. The patients were reviewed at 6 and 24 weeks. Partial or complete disintegration of the calcareous deposit was observed in 50% of the patients in group 1 and 64% of the patients in group 2 (P < .01). According to the Constant score, ratings increased from 48 to 71 points in group 1 (P < .001) and from 53 to 88 in group 2 (P < .001) (out of a total possible 100 points), the end values of both groups differing significantly (P < .01). After 24 weeks, 52% of the patients in group 1 rated the results of treatment as good or excellent, compared with 68% in group 2 (P < .01). No improvement was reported by 24% versus 10%, respectively, at the 24-week follow-up.

Calcinosis↗
PubMedDate not supplied

[Scoliosis and hip flexion contracture in Duchenne muscular dystrophy].

UNLABELLED: Spinal deformity is common in muscular dystrophy and usually occurs after loss of walking ability. Unlike in idiopathic and other scoliosis forms, there seems to be no side preference of the convexity. Aim of the study was to analyse, if there is any relation between incidence and extent of walking ability, lower limb contractures and development of scoliosis. METHODS: In a retrospective study, 45 patients with Duchenne muscular dystrophy who underwent surgery were analysed, concerning walking ability, contractures of lower extremities and scoliosis. RESULTS: 1: No scoliosis was observed in ambulatory patients. 2: 96% of the wheelchair bound patients suffered from scoliosis. 3: 96% of the scoliosis patients had hip flexion or abduction contractures. 4: In 12 of 15 cases with side-different contractures, scoliosis tended to the side with the greater contracture. CONCLUSIONS: The influence of hip contracture and pelvic obliquity on scoliosis is discussed controversially. Concerning muscular dystrophy, there seems to be a positive correlation between convexity and hip contracture. If this is a causal relation or if there is a faster progression of structural alteration of the muscles on one side has to be further investigated.

Adolescent↗
PubMedDate not supplied

[Function of back extensor muscles in upright standing position and during sitting with identical back posture--an electromyography study].

PROBLEM: There is a controversial discussion about the loading of the spine by the force of the extending muscles of the back in upright sitting with the back curved as in upright standing. Experimental studies investigating this issue are still lacking. METHODS: In the study presented in this paper we measured in 30 subjects the activity of the extending back muscles both in a natural upright standing posture and in sitting with identical posture of the back as recommended in some back training programs. To this end we recorded the electromyographical surface activity of the back muscles at four levels of the spine in both postures. The EMG activities were intraindividually normalized with reference to the respective activity recorded at maximum voluntary isometric contraction (MVC). RESULTS: At three of the four levels of the spine examined, the group averages of the EMG activity in sitting were significantly higher than in standing (p < 0.001). The maximum activity enhancement evaluated was 48% at Th12. The force of the lower back muscles in sitting with a posture of the back as in natural upright standing could be estimated to be at least greater than 30% of the force at MVC. CONCLUSION: The force needed to enforce in sitting a posture of the back identical to the posture at natural standing entails lower back muscle fatigue in a few minutes. The results of our study agree with recent experimental findings about an increased loading of the spine in lordotic sitting.

Adolescent↗
PubMedDate not supplied

[Necessary steps for implementing the Australian DRG system].

The introduction of the DRG-System will be followed by severe changes in the German hospitals. From the view of today departments or hospitals are threatened by closing if they do not deal with the new rules. A common implementation of this system by all participants of the health system is necessary before the introduction at 1.1.2003. Only this will guarantee an adequate presentation of the different defaults in the future because the conditions of the implementation of the system are not qualified yet. The hospitals are forced to prepare the introduction of the DRG-System, however. Only the Arrangement of an extensive documentation of all diagnoses and all conservative and operation methods together with a cost--cutting administration will be consequently followed by a financial healthy situation. The most important points to be emphasized are the medical documentation, the controlling, the improvement of the processes and the computer assisted documentation. By an intensive information concerning all further resources the involvement of the employees of the hospital is a necessary part for the success of the introduction.

Cost Control↗
PubMedDate not supplied

[Disc replacement with the SB Charité endoposthesis - experience, preliminary results and comments after 35 prospectively performed operations].

UNLABELLED: Aim of this prospective study was an investigation concerning the indication for the implantation of an artificial disc endoprosthesis and the rating of this operation. METHOD: 35 patients with 11 bi- and 24 monosegmental implanted disc endoprosthesis were observed over an average follow-up of 14.7 months. Indications for the operation were: unsuccessful, orthopedic conservative treatment > 6 months, segmental pain, age < 45 years, evidence of a radiologic (MRI) demonstrable mono- or bisegmental disc degeneration with or without disc prolabation, exclusion of psychogenic disease and positive preoperative, diagnostic measures. RESULTS: The average stay in the hospital was 16.8 days (preoperative: 4.3 days), the average operation time 85.5 minutes, the average blood loss was 125 ccm. 23 patients were operated in L 5 / S 1, 20 in L 4 / 5 and 2 in L 3 / 4. NSAR was given in 33 patients preoperatively, opiates in 2 further patients, postoperatively NSAR was necessary in 5 patients, opiates in 2 patients. The preoperative angle of lordosis (L 1 - S 1, n = 25) was changed from 35.6 degrees to 42.6 degrees (20,2 %), the segmental angle from 19 degrees to 30 degrees (57.5 %). CONCLUSION: The implantation of the artificial disc was followed by a good pain relief in patients suffering from a mono- or bisegmental disc degeneration. In patients with a facett joint arthrosis and elderly patients > 45 years this method cannot be used, the indication in patients with failed back surgery syndrome cannot be estimated yet. Improvements of the instrumentation and the discussion in the case of revisional operations are mandatory.

Adult↗