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Biomedical subjects

H Merk

Publications and source records attributed to H Merk.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

[Revisions after arthroscopic interventions in the subacromial space].

PROBLEM: In the present study, we evaluated the failure and revisions rates after arthroscopic subacromial decompression (SAD). METHOD: We examined 83 patients who were treated with arthroscopic subacromial decompression for primary shoulder impingement (stage II and stage III according to Neer) at an average follow-up time of 30 months. Hereby, special attention was paid to the revision operations resulting from our treatment. RESULTS: In patients with impingement stage II, the mean follow-up Constant-score was 84.7 (SD +/- 16.7) while in patients with impingement stage III it was 78.0 (SD +/- 21.8). In ten patients (12%) revision operation had to be performed, nine of them with initial stage II impingement and one with initial stage III impingement. Reasons for revisions were persisting or increasing pain as well as functional dissatisfaction. At the follow up examination, six of these revised patients (60%) were satisfied with the result. The mean follow up Constant-score in the revised patients was 77.3 (SD +/- 17.4). In 60% of the revised patients the necessity for the revision operation was directly related to the technical problems at the primary operation, in 40% we found reasons not related to the primary SAD. CONCLUSIONS: Technical falls are the most common cause for the need of revision operations after SAD. This demonstrates how demanding this kind of operation procedure is. In case of revision operations individual strategies should be developed in which the decision whether to perform arthroscopic or open revision procedures is of special importance.

Acromion↗
PubMedDate not supplied

[Implantation of a Harms titanium mesh cylinder for vertebral body replacement in spinal metastases].

OBJECTIVE: Vertebral metastases are quiet common and may result in vertebral collapse, spinal instability, and progressive neurological compromise. An anterior approach is the accepted method for decompression and stabilization by vertebral replacement. There is still need for discussion regarding the material of the replacement device. Here, the authors report on Harms' titanium cage (DePuy-Motech) for vertebral replacement. METHODS: From 1992 until 1995 17 patients with spinal metastases were treated by anterior vertebral replacement at the Orthopaedic Department, University of Magdeburg. Indications for the procedure were single metastases and respectively, progressive neurological deficit with vertebral destruction seen radiologically. Implantation of the cage was performed solely or in combination with anterior or posterior instrumentation. Pre- and postoperative assessments were evaluated by clinical scores. RESULTS: Mean follow-up was 9.3 months. At the end of our study 11 patients had died (mean survival 6.7 months). Mean follow-up of the surviving 6 was 9.8 months. Patient's daily activity (Karnofsky) improved in 8 cases, became worse in 4 cases, and did not change in 5 cases. Neurologically (Frankel) there was improvement in 3 patients, deterioration in 4 patients, and no change in 10 patients. Walking ability showed improvement in 6 cases, deterioration in 3 cases and no change in 8 cases. Relief of pain (Moskowitz) was reported by 12 patients, no patient complained of increasing pain, 5 patients reported no change, and 10 patients were pain-free. CONCLUSION AND CLINICAL RELEVANCE: In most cases with spinal metastases, the quality of life may be improved by vertebral replacement with Harms' titanium cage. Amelioration of clinical symptoms such as neurological deficit, pain, and tack of walking ability occurred in most patients.

Adult↗
PubMedDate not supplied

[Prospective randomized comparative study of early functional outcome of 2 knee joint endoprosthesis systems--rotation plateau versus fixed polyethylene inlay].

AIM: Different systems are used for total knee arthroplasty (TKA). Compared were a press-fit femur condyle replacement system with fixed tibial PE-inlay versus a rotating tibia component system with an emphasis on the early functional results. METHOD: Patient selection and the use of the Knee Society Score for this randomized and prospective study were based on the directives for TKA of the german Society for Orthopaedic and Trauma Surgery (DGOT). We examined the patients post-operatively after 1 week, 2 weeks, 6 weeks, 3 months, 6 months, and 1 year. RESULTS: After 6 weeks an increase of the total knee score could be seen in both groups. The total knee score of the rotating tibia component increased from 93.96 pre-operatively to 113.57 after 6 weeks, to 139.82 after 3 months, to 154.32 after 6 months, and to 159.65 after one year. The total score with the fixed PE-inlay increased from 79.75 to 111.5 after 6 weeks, to 128.25 after 3 months, to 134.08 after 6 months, and to 130.08 after one year. CONCLUSION: After 6 weeks the implant with the rotating tibia component showed a lasting higher score as compared to the implant with a fixed PE-inlay component using the same early rehabilitation and mobilization techniques.

Aged↗
PubMedDate not supplied

[Influence of intertrochanteric varisation osteotomy on the gait of children with Perthes disease].

BACKGROUND: The purpose of this study was to investigate possible effects of intertrochanteric varisation osteotomy on the gait of children with Perthes disease. PATIENTS: Clinical and radiographic examinations and gait analysis were conducted on 50 children. METHOD: Gait analysis was conducted using the GANGAS system. RESULTS: Despite predominantly very good or good results shown by the clinical and radiographic examinations, gait analysis detected various functional deficits. CONCLUSIONS: The examinations show that for the group of patients described, gait analysis is a valuable method of recording functional deficits and early recognition of the need for postoperative, physiotherapeutic treatment, thus helping to avoid chronificating alterations of the gait and, consequently, potential secondary damage.

Bone Malalignment↗
PubMedDate not supplied

[Normalization of histomorphometric and biomechanical parameters through metabolic control of fracture healing in spontaneously diabetic BB/OK rats].

AIM: The objective of this study was to examine changes in the histomorphometrical and mechanical parameters of bone during fracture healing in dependence on the diabetic metabolic state in spontaneously diabetic BB/O(ttawa)K(arlsburg) rats. METHODS: Based on blood glucose values at the time of surgery, postoperative blood glucose course and postoperative insulin requirements, 90 spontaneously diabetic BB/OK rats were divided into groups with well compensated or poorly compensated metabolic states. Forty-five LEW.1A rats served as the normoglycemic controls. The femurs were fractured in a standardized procedure and then allowed to heal for 2, 4 and 6 weeks. RESULTS: In terms of bone histomorphometry, our study showed that, within the first four weeks after fracture, severe mineralization disorders occurred exclusively in the rats with poorly compensated diabetic metabolic states, with a significant decrease of all fluorochrome- based parameters of mineralization, apposition, formation and a significantly prolonged timing of mineralization, as well as significantly decreased values of biomechanical properties in comparison to the spontaneously diabetic rats with well compensated metabolic states and to the control rats. CONCLUSION: With a strictly controlled insulin therapy and a resulting well compensated diabetic metabolic state, severe mineralization disorders and the decreased values of biomechanical properties in the fracture repair in the poorly compensated diabetic metabolic state of the experimental animal can be avoided.

Animals↗
PubMedDate not supplied

[Refined adenoviral transduction for controlled gene transfer into human adult mesenchymal stem cells].

AIM: Adenoviral gene transfer remains a powerful tool for basic research purposes. We hypothesize that adenoviral transduction of human mesenchymal stem cells (hMSC) in vitro can be improved by refined use of experimental parameters. METHODS: hMSCs were transduced by adenoviral vectors encoding Luciferase or BMP-2 at a selection of multiplicities of infection (MOI) and exposure times. Transgene production and total protein content were measured. To determine practical relevance, expression of the bone marker genes Runx2 and Type I collagen was analyzed by quantitative PCR. As a phenotypic marker alkaline phosphatase was assessed. ANOVA and post hoc statistical analyses were used to determine differences among data (p < 0.05). RESULTS: Prolonged exposure led to a decrease in transgene production and total protein content. Increasing MOI at exposure of up to 4 hours resulted in a higher production of the transgene. Transfer of the hBMP-2 gene promoted an enhanced lineage progression to the osteoblast phenotype indicating biological activity. CONCLUSION: Time of exposure is of major importance for toxicity in vitro and should not exceed 4 hours for hMSC. While increase in exposure time leads to cell death, surviving cells, up to a certain limit, seem to compensate by increasing production of the transgene indicating that transduction efficiency cannot be positively measured in a binary yes-or-no scheme.

Adenoviridae↗
PubMedDate not supplied

[Anatomic reduction and monosegmental fusion for high-grade developmental spondylolisthesis L5/S1].

INTRODUCTION: Developmental spondylolisthesis leads to lumbosacral kyphosis with retroversion of the sacrum and lumbar hyperlordosis. The overall sagittal profile of the spine is affected. The deformity is progressive during growth. This retrospective study describes a technique for complete reduction with clinical and radiological evaluation. PATIENTS: Thirty-four patients (mean age 16 years 3 months, 10 males, 24 females) with severe developmental spondylolisthesis L5/S1 (Meyerding grades 3 to 5) were operated on between February 1997 and July 2002. METHOD: Reduction was achieved by temporary transpedicular instrumentation of L4. These screws were removed at the end of the operation or 12 weeks later. RESULTS: Mean slippage was corrected from 76 % preoperatively to 10 % postoperatively. Segmental kyphosis L5/S1 improved from + 21 degrees preoperatively to - 7 degrees postoperatively. Sacral inclination was 34 degrees preoperatively, 43 degrees postoperatively, and 47 degrees at latest follow-up. 76 % of the patients were pain free at the latest follow-up. In 4 patients a fusion at L4/5 was performed due to subsequent decompensation. CONCLUSION: The technique described allows for a nearly anatomic reduction with correction of slippage as well as segmental kyphosis. Correction of the local deformity with monosegmental fusion L5/S1 improves dramatically the overall sagittal profile of the spine. Fusion of the primarily healthy segment L4/5 can be avoided.

Adolescent↗
PubMedDate not supplied

[Hemivertebra resection in congenital scoliosis -- early correction in young children].

BACKGROUND: Congenital scoliosis due to hemivertebrae usually progresses during further growth and leads to severe deformities. Early correction in young children is therefore required. PATIENTS: Thirty-six hemivertebrae in 33 children aged 1 to 6 years (average 3 years 5 months) underwent surgical intervention. Mean follow-up was 4.5 years (2 months to 13 years). METHODS: The hemivertebra was resected by a posterior approach. The gap after resection was closed by compression via a transpedicular instrumentation, thus correcting the scoliotic deformity. RESULTS: Mean Cobb angle of the main curve was 45.9 degrees preoperatively, 11.9 degrees postoperatively, and 9.9 degrees at latest follow-up. The compensatory cranial curve improved spontaneously from 18.4 degrees preoperatively to 5.0 degrees postoperatively and 3.7 degrees at latest follow-up. The compensatory caudal curve improved from 21.3 degrees to 6.7 and 5.4 degrees. The angle of kyphosis was 22.8 degrees preoperatively, 8.9 degrees postoperatively, and 6.8 degrees at latest follow-up. There was one infection, 2 pedicle fractures, and 3 implant failures. In 3 patients additional operations were performed due to new developing deformities. CONCLUSION: Correction surgery of congenital scoliosis should be performed early before the development of severe local deformities and secondary structural changes. Posterior resection of the hemivertebrae with transpedicular instrumentation allows for early intervention in very young children. Excellent correction in both the frontal and sagittal planes, and a short segment of fusion allow for normal growth in the unaffected parts of the spine.

Age Factors↗
PubMedDate not supplied

[Preoperative planning and computer assisted surgery in ankylosing spondylitis].

AIM: The following study describes a technique for preoperative planning and computer-assisted correction osteotomy in the treatment of ankylosing spondylitis. The effect on the overall sagittal profile is evaluated. METHOD: Kyphosis was corrected by a posterior closing wedge osteotomy. Angle and localisation of the wedge were exactly planned preoperatively and transferred to a navigation system. The osteotomy was then performed along the premarked lines with image-guided tools. Nine patients aged 40 to 61 years (average 46 years) were operated on. Follow-up time averaged 12 months (1 to 33 months). RESULTS: The planned angle of the wedge osteotomy was an average of 30 degrees (range 24 degrees to 40 degrees ) preoperatively. Postoperatively, the angle averaged 30 degrees as well (range 22 degrees to 41 degrees ). The individual difference between real and planned angle was an average of 2.7 degrees (range 1 degrees to 6 degrees ). Sacral inclination was 23 degrees preoperatively (range-- 6 degrees to 40 degrees ) and was corrected to 40 degrees (range 27 degrees to 49 degrees ). Anterior displacement of the gravity line averaged 112 mm preoperatively (range 47 to 196 mm) and was corrected to 31 mm (range--7 to 135 mm) postoperatively and 38 mm (range-- 21 to 137 mm) at latest follow-up. CONCLUSION: Precise preoperative planning and correction osteotomy exactly according to this planning allow for an excellent correction of the sagittal profile even in severe ankylosing spondylitis. Pelvic tilt and gravity line are normalised, the patient is able to adopt an ergonomic upright position. Navigation facilitates the intraoperative transfer of the preoperative planning.

Adult↗
PubMedDate not supplied

[Correlation of pathological clinical hip symptoms in the sonographic study of infant hips].

The relevance of clinical signs of infant hip dysplasia and the importance of a sonographic newborn-hip screening are often discussed. Between 1984 and 1990 at our department 6532 infant hips were examined both clinically and sonographically. Sonographic hip findings were pathological in 71.7% of the hips with positive clinical Roser-Ortolani sign and in 100% of the hips with positive Hilgenreiner sign. In contrast, pathological hip types according to Graf were seen only in 18% of the hips with limitations of the abductions of the hip joint. Examining other clinical signs for infant hip dysplasia within this study, as well we can conclude, that only the Roser-Ortolani sign and that of Hilgenreiner showed a high specificity for infant hip dysplasia, while most of the clinical signs e.g. limitation of abduction in the hip joint are rather unspecific.

Diagnostic Errors↗
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[Arthroscopic repair of the glenoid labrum using the 3-point knot technique. Early results with consideration to different postoperative immobilization time periods].

There are different opinions on the duration of post-operative shoulder immobilisation following arthroscopic repair of labrum tears. Between 1993 and 1994 at our department arthroscopic repairs of the glenoid labrum as described by Habermeyer (15, 16) have been performed in 38 patients. In 20 of these patients postoperative treatment included immobilisation of the operated shoulder in a Gilchrist-bandage for 3 weeks, while in the remaining 18 patients this postoperative immobilisation period was decreased to only 1 or 2 weeks. Physiotherapy started the day after the operation, using a device for passive-motion exercises. The mean follow-up time of our examinations was 15.4 month. The mean score by Rowe rose significantly from 20.0 preoperatively to 82.6 at the follow-up examination. Results were excellent or good in 89.4% of all cases, new shoulder dislocations did not occur in any case. Patients having their shoulders immobilised for 3 weeks reached significantly higher Rowe-scores at our follow-up than those patients, whose shoulders were immobilised for only 1 or 2 weeks. Therefore, postoperative management following arthroscopic repair of labrum tears should include immobilisation of the operate shoulder for 3 weeks and an early start of passive-motion exercises.

Adolescent↗
PubMedDate not supplied

[The use of ultrasonography in peroneal paralysis].

We report the importance of ultrasound in 5 cases of neuropathies caused by popliteal compression of the peroneal nerve. The ultrasound is helpful for the indication of operative decompression. The ultrasound is a proper diagnostic method if sciatica could not be excluded. Unfortunately, not every compression can be evaluated by this method alone.

Adult↗
PubMedDate not supplied

[The congenital dislocation of the hip joint in ultrasound examination--frequency, diagnosis and treatment].

BACKGROUND: A real congenital dislocation of the hip joint is very rare. Because of the severeness of the disease an immediate diagnosis and begin of treatment is required. PATIENTS: Between 1984 and 1995 clinical and sonographic screening examinations at 4177 newborns were performed at our hospital. METHODS: We analyzed our patients retrospectively and found out all cases of congenital dislocation of the hip joint. All these cases were classified and the results of treatment were determined. The clinical success of our strategy of treatment was described. RESULTS: Among the 4177 observed newborns 39 cases of congenital dislocation of the hip joint in 27 children were found. We diagnosed the hip type IIIa, IIIb and IV according to Graf in 28.2 and 9 cases respectively. After 12 month a complete healing rate of 95 percent was exhibited with the functional management strategy. Five percent of the affected joints showed a residual dysplasia. The rate of residual dysplasias was 2.5%. CONCLUSIONS: The good prognosis after our early treatment strategy severe congenital dislocation of the hip joint underlines the use of earliest therapy together with a hip screening program.

Germany↗
PubMedDate not supplied

[Results of mobilization under anesthesia in adhesive capsulitis in relation to stage of the disease].

PROBLEM: Mobilisation under anaesthesia is a well approved method for the treatment of idiopathic adhesive capsulitis, the best time to perform the mobilisation, however, is difficult to define. MATERIAL AND METHODS: Thirty-nine patients who had been treated with mobilisation under anaesthesia for idiopathic adhesive capsulitis stage II or III were examined at an average follow-up time of 3.4 years. RESULTS: This therapy failed in 10.3% of the patients. There were no differences in the follow-up results between both groups of patients, limitations in the range of motion remained in 20% of all patients. At follow up the average CONSTANT Score of the stage II patients was 86.8, that of the stage III patients was 89.9 points. However, manipulation under anaesthesia showed a significantly better influence on the course of the disease in patients with stage III than in patients with stage II adhesive capsulitis. CONCLUSION: Mobilisation under anaesthesia is a successful therapy in adhesive capsulitis stage III, but should be performed in adhesive capsulitis stage II only in cases of decreasing pain in which the limitation in the range of motion is the main symptom.

Adult↗
PubMedDate not supplied

[Comparison of functional outcome in implantation of Natural Knee knee prostheses with and without patellar resurfacing].

PROBLEM: Despite the great progress in knee arthroplasty made within the previous decade the problem of patellar resurfacing is still unsolved. MATERIAL AND METHODS: In a retrospective matched-pairs study in 62 patients with Natural Knee endoprostheses including one group with and another without patella resurfacing were compared. Results were assessed according to the American Knee Society Score and the patients subjective assessments. RESULTS: At an average follow-up time 2 years there were no differences in the clinical findings and the patients subjective opinions between both patient groups. However, patients with rheumatoid arthritis and patella resurfacing showed significantly better results in both categories than those rheumatoid patients without patella resurfacing. CONCLUSION: Summing our results up we cannot give a general advise towards the use of patella resurfacing in knee replacements. In patients with severe arthrosis of the femoro-patellar joint and in patients with rheumatoid arthritis, however, the patella replacement is considered to be the therapy of choice at our department.

Aged↗
PubMedDate not supplied

[Evaluation and prognosis of changes in the femur end of the hip in hip dislocation].

Long-term observations proved the necessity of careful control of the development of femur head epiphysis in case of dislocated hip joint. The occurrence of femur head necroses can be greatly reduced by a sparing functional treatment. Endogenously conditioned constructive disturbances, which can be found in 5 to 7 p.c. of all cases, have to be clearly distinguished from head necroses.

Child↗
PubMedDate not supplied

Porphyria cutanea tarda.

Porphyria cutanea tarda (PCT) is the most frequent form of porphyria. The underlying enzymatic defect in PCT is a reduced activity of the enzyme uroporphyrinogen decarboxylase (Uro-D). Four different types of Uro-D disturbances are known. Pseudoporphyrias such as porphyria cutanea uraemica or drug-induced PCT-like skin symptoms are distinguished from PCT. Porphyrinogens such as estrogens or alcohol, or other inducers of P450 isoenzymes provoke PCT. Polymorphisms of P450 isoenzymes, iron overload and infection with hepatitis C virus play an important role in the etiopathogenesis of disease manifestation. Dominant clinical symptoms are bullae, increased cutaneous vulnerability, hypertrichosis and elastosis. Biochemically, total porphyrin levels in urine are increased with a predominance of uroporphyrin and heptacarboxylic porphyrin. Isocoproporphyrin is demonstrable in feces. Best therapeutic strategies are the oral administration of chloroquine 125 mg twice a week and repetitive bloodlettings or the combination of both.

Coproporphyrins↗