Search PubMed⌕ Search

Biomedical subjects

F U Niethard

Publications and source records attributed to F U Niethard.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

[Clavicular pseudarthrosis in childhood: differential diagnosis, clinical aspects, therapy and results].

AIM: Both congenital as well as post-traumatic pseudarthroses of the clavicle are very rare diagnoses in childhood. This study evaluates operative and non-operative therapy in relation to diagnosis, clinical appearance, and results. METHODS: A retrospective study was performed on all patients with pseudarthrosis of the clavicle in childhood. The data were obtained from medical records. Follow-ups were performed on patients who had undergone surgery. RESULTS: A total of 15 patients with 16 pseudarthroses were included, of these five patients had congenital and nine patients had post-traumatic pseudarthroses. One patient with a bilateral defect was diagnosed as having cleidocranial dysostosis. Concerning the patients with congenital pseudarthrosis, cosmetic appearance was the leading complaint while patients with post-traumatic pseudarthrosis suffered from pain and impaired function of the shoulder joint. Nine patients underwent surgery, including two patients with congenital, and seven with post-traumatie lesions. CONCLUSION: While patients with congenital pseudarthrosis mostly achieve good functional results by means of conservative therapy, surgery is optional in relation to the severity of cosmetic damage. However, the majority of post-traumatic lesions require operative therapy due to associated pain and restricted function.

Adolescent↗
PubMedDate not supplied

[Diagnosis and differential diagnosis of extraskeletal, para-articular chondroma of the knee].

AIM: Extraskeletal chondromas in the region of the knee joint are very rare tumors which may cause diagnostic problems and have concomitant therapeutic consequences. METHOD: In a case report we present the clinical, radiological and histological features of an a extraskeletal chondroma. RESULTS: A 47-year-old female patient presented with an infrapatellar, painless tumor of the knee joint. The clinical features were unspecific. On plain X-ray images, calcifications were visabled within Hoffa's fat pad. An important preoperative imaging procedure was MRI, which showed a well defined mass of 2.5 cm in diameter with a hyperintense signal on fat suppressed images. Subsequent operative therapy involved marginal resection of the tumor. CONCLUSION: The differentiation of this entity especially from myxoid chondrosacroma and synovial chondroamatosis was crucial with respect to an adequate therapy. Further differential diagnoses included heterotopic ossifications, synovial sarcoma, mesenchymoma and soft-tissue osteosarcoma.

Adipose Tissue↗
PubMedDate not supplied

[Comparative analysis of lumbar spine degeneration documented by x-rays versus large specimen cryomicrotome sections].

AIM OF THE STUDY: The extent of degenerative changes in the lumbar spine as seen on conventional radiographs is interpreted on the basis of visualized osseus structures and indirect signs such as diminution of disc height. In order to analyze the accuracy of these interpretations we compared and correlated different stages of degeneration in conventional radiographs with cuts of large-specimen cryomicrotome sections (LSCS), offering a direct macroscopic vision of the degenerative anatomic features. METHOD: A total of 50 human cadaver lumbar spines with 251 spine segments (Th 12 - S1) was investigated by plain radiograms and LSCS. The degenerative changes were differentiated into 5 stages for both diagnostic measures. Criteria for radiological degeneration were: diminution of disc space, presence of osteophytes and sclerosis of the endplates. Degenerative changes as seen by LSCS were evaluated by the following features: cracks in the endplate, bleeding into the intervertebral disc, alignment of the annulus fibrosus fibres and osseous alterations in the spine segment. RESULTS: Complete matches of the evaluated radiological and macroscopic stages of degeneration were observed in 206 cases. A difference of 1 degree on the degeneration scale was registered in 42 segments, whereas a difference of 2 degrees was seen in 3 cases. The correlation coefficient between the degeneration stages of the two diagnostic measures scored rho = 0.883. CONCLUSION: The comparison of the different degrees of degeneration in the lumbar spine as evaluated by both plain radiographs and LSCS revealed a good correlation.

Adolescent↗
PubMedDate not supplied

[First experiences with fluorodeoxyglucose-positron-emission tomography (FDG-PET) in the evaluation of painful total knee and hip joint replacements].

AIM: The aim of the study was to describe first experiences using FDG-PET in the examination of painful arthroplasties. METHOD: 12 patients prior to revision of a total hip or knee joint replacement underwent PET. Histopathology, microbiological analysis and intraoperative diagnosis were compared to preoperative PET findings. RESULTS: The analysis of intraoperative findings, of microbiological examinations and of histopathology showed that besides the well known determinants infection and early postoperative granulation tissue, polyethylene wear induced foreign-body reaction was a major cause for increased FDG consumption. CONCLUSION: In vivo imaging of marked foreign-body tissue reaction induced by polyethylene wear is feasible by FDG-PET. This observation, however, leads to reduced specificity of PET imaging for the diagnosis of periprosthetic infection.

Aged↗
PubMedDate not supplied

[The value of peripheral quantitative computed tomography (pQCT) in the diagnosis of osteoporosis].

AIM: To evaluate the accuracy of distal radial pQCT in discriminating between osteoporotic fracture and non fracture cases and its efficiency to predict fractures. METHODS: Densitometric data determined with an XCT 900 Stratec pQCT device at the distal radius of women who had suffered distal radius (57), spinal (87) or femoral neck fractures (21) before or after measurement were compared with densitometric data of age-matched healthy women (265) and were analyzed in regression tests. Women whose fractures occurred before measuring were selectively analyzed. RESULTS: More significant differences between fracture and non fracture groups were obtained by trabecular bone density (TBD) (r2radius = 0.531, r2spine = 0.528, r2femur = 0.711, p < 0.001) than by total bone density (BD) (r2radius = 0.468, r2spine = 0.495, r2femur = 0.605, p < 0.001). In the radius and spine group TBD data determined before fracture showed less significant differences than those determined afterwards, whereas in the femur group TBD data were almost equal. All femur fractures could be predicted. As TBD decreased, the relative risk of fracture increased by gradients of m radius = 0.017, m spine = 0.013, and m femur = 0.027 in the linear regions of the risk curves. CONCLUSION: Selective measuring of TBD at the distal radius enables one to detect bone loss at an early stage and to estimate the risk of future fractures not only at the point of measurement.

Aged↗
PubMedDate not supplied

[Portable NMR-MOUSE: a new method and its evaluation of the Achilles tendon].

AIM: The increased demands placed on the Achilles tendon in recreational and professional sports have led to a rise in pathological changes in this anatomic region. Magnetic resonance evaluations of the tendon have proven to be a valid but expensive and stationary diagnostic tool. In this study, a new mobile NMR sensor was to be tested in the evaluation of the Achilles tendon. METHOD: The technical development of the so-called NMR-MOUSE ( Mobile Universal Surface Explorer) represents a novelty with an open and portable sensor. To appraise its diagnostic efficacy, healthy athletes (professional soccer players, track and field, as well as aquatic athletes), healthy controls and patients with Achilles tendon lesions were evaluated. As an accessible, sensitive and reproducible parameter for the study the transverse relaxation time T2 with its angular dependency was chosen. As part of the examination, the relaxation times of the skin, the tendon and the surrounding soft tissue were determined. RESULTS: During the evaluation with the NMR-MOUSE, the skin and peritendineous tissue exhibited relatively long T2 relaxation times, while the tendon itself had significantly shorter T2 times, allowing for a clear differentiation of the structures. The T2 relaxation time of the Achilles tendon in the control group averaged 5.8 ms. The MRI-MOUSE was able to demonstrate an increase in the T2 relaxation times in patients with pathological lesions of the tendon due to the increased water retention of the tissue. CONCLUSION: The novel NMR-MOUSE represents a cost efficient and portable sensor, which allows for a reliable evaluation of surface structures, such as the Achilles tendon. The anisotropic structure of the tendon and the surrounding soft tissue can be reliably differentiated with the help of the NMR-MOUSE.

Achilles Tendon↗
PubMedDate not supplied

[A new method to optimize the adhesion between bone cement and acetabular bone in total hip arthroplasty].

AIM: In cemented total hip arthroplasty cup loosening occurs earlier than stem loosening in most of the cases. This is mainly caused by the lack of stabile adhesion between the hydrophobic bone cement and the hydrophilic bone surface of the acetabulum. The aim of this study was to develop a multilayer amphiphilic bonding system which prevents the hydrolytic debonding at the bone cement-bone interface, thus optimizing the compound stability. METHOD: In a first series of tests a standardized three-point-bending test was performed to determine the compound stability of the bone cement-bone interface. The bony test specimens were immersed into physiologic NaCl solution to simulate the hydrolytic in situ conditions and contaminated with blood to simulate the intraoperative bleeding of prepared acetabular bone surfaces. In a second series of tests polyethylene cups were implanted into the acetabular cavity of sheep using the current cementing technique. Acetabular bone stock was prepared differently (subchondral sclerotic zone preserved vs. removed, additional drilling into the acetabular roof, with vs. without the multilayer bonding system) in intra-individual comparison of both acetabular sides. To ascertain the bone cement-bone stability a torsional-turn out test was performed on an universal testing machine. RESULTS: In the three-point-bending tests the compound stability between bone cement and bone was 50- to 100-times higher with the use of the multilayer system. In the torsional-turn out tests the compound stability showed in mean a 1.8-fold increase of the interface strength in case of preconditioned acetabular cavities with the multilayer bonding system. CONCLUSION: The developed multilayer bonding system optimizes the interface strength between acetabular bone stock and bone cement significantly for cemented cups in total hip arthroplasty. In contrast to cementing techniques with complete removal of the subchondral sclerotic zone (in order to optimize micro-interlocking) the biologically effective and load bearing acetabular bone stock can be preserved using the newly developed multilayer bonding system. This aspect might be highly important especially with regard to possible acetabular bone defects caused by the process of aseptic cup loosening.

Acetabulum↗
PubMedDate not supplied

[Complications after harvesting of autologous bone from the ventral and dorsal iliac crest - a prospective, controlled study].

INTRODUCTION: In a prospective, controlled study, donor site morbidity after bone graft harvesting from the anterior and posterior iliac crest was documented. METHODS: In 113 patients, monocortical to tricortical bone grafts were taken from the anterior (n = 73) or dorsal (n = 40) iliac crest. Bone graft size (0.4 - 43 cm 3, median 9.7 cm 3), Operation time (12 - 65 minutes, median 28 minutes), and postoperative donor site were documented. RESULTS: Donor site morbidity was higher after harvesting from the ventral than from the dorsal iliac crest: total morbidity 48 vs. 32.5 %, large haematomas 9.6 vs. 7.5 %, moderate haematomas 34.3 vs. 15 %, wound dehiscence 2.7 vs. 0 %. One revision operation was necessary because of a large haematoma at the ventral crest. After harvesting from the ventral iliac crest, there was one fracture ofthe iliac wing and one avulsion fracture of the iliac crest. There were no infections, no injuries of arteries or of the lateral femoral cutaneous nerve and no hemiation. After harvesting from the dorsal iliac crest, there were no major complications. CONCLUSION: Bone graft harvesting from the posterior iliac crest should be preferred over harvesting from the anterior iliac crest beeause of the substantially reduced donor site morbidity. Harvesting from the ventral iliac crest should have a clear indication, synthetic bone substitutes should be taken into consideration.

Adult↗
PubMedDate not supplied

[Indications and implementation of recommendations of the working group "Tissue Regeneration and Tissue Substitutes" for autologous chondrocyte transplantation (ACT)].

For the treatment of full-thickness articular cartilage lesions of the knee joint, as a result of trauma or osteochondritis dissecans, a variety of biological reconstruction techniques have been developed. Different studies, some of which were performed as randomised, prospective clinical studies, showed that the autologous chondrocyte transplantation (ACT) provides the most satisfying and reliable method of cartilage reconstruction in the adult when applied to defects exceeding 4 cm (2). Based on these results, ACT seems to be of economic benefit, as the risk of developing osteoarthritis correlates significantly with the size of the cartilage defect, when not treated properly and in time. Surveying the studies on basic scientific aspects of ACT, cartilage defect animal models and clinical studies, it can be concluded that clinical results of ACT depend on a variety of factors. In this review, published by the joined advisory board of the German Societies of Traumatology (DGU) and Orthopaedic Surgery (DGOOC), we summarize the current knowledge available and the state of the art concerning ACT. Especially we discuss the advantages of different procedures, methods for treating knee cartilage defects and factors that influence the outcome of the different treatment regimens, with the aim to develop guidelines for the correct indication and application of the ACT.

Adult↗
PubMedDate not supplied

[Nation-wide registration of limb deficiencies in Germany].

AIM: A detailed registration of the frequency and the aetiology of limb deficiencies has been established for the first time in Germany. METHOD: According to the ESPED model (Documentation of rare paediatric diseases in Germany) we send out at an interval of three months a questionnaire for registration of live births, still births and their limb deficiencies to 1 073 gynaecological hospitals. In case of a positive response for a limb deficiency a second questionnaire is sent for details about pregnancy, birth and family. The limb defects are registered according to the ICD-10 classification and statistically analysed. RESULTS: Current acquisition period: 48 months (April 2000-April 2004). Total number of registered births: 1 070 541. Number of live births with limb deficiencies: 1 534 (0.14 %). Number of still births with limb deficiencies: 55 (1.7 %). Minor limb deficiencies such as polydactyly (22.4 %) are more frequent than major deficiencies of the tibia (1.0 %) or of the fibula (1.6 %). A familiar disposition is found in 9.7 %. A correlation to the profession of parents or their age (mother: 29, father: 33), or nicotine abuse could not be detected. The numbers of special features during pregnancy (amniocentesis in 3.3 %, oligohydramnion in 0.5 %, polyhydramnion in 0.3 %, etc.) and during delivery (relation between normal delivery and caesarean section = 59.5 %/29 %, etc.) were similar to the frequencies in the normal population. CONCLUSIONS: Our register represents the largest study world-wide in respect to the birth rate and the most accurate record of limb deficiencies. In the current acquisition period no correlation of the registered limb deficiencies to environmental effects, individual misbehaviour, exposed professional group and peculiarities during pregnancy and parturition could be found. The continuation of our register is essential for further detection of the incidence and aetiology of limb defects.

Abnormalities, Multiple↗
PubMedDate not supplied

[Reduction of spondylolisthesis by temporary adjacent segment distraction].

AIM OF THE STUDY: Multiple instrument systems are currently available for the reduction of spondylolisthesis, where posteriorly oriented tensile forces are directly acting on the slipped vertebra. The aim of this clinical study was to evaluate the clinical efficacy of a new indirect reduction manoeuvre applied to the lumbar spine. METHOD: A total number of 32 patients (14 female, 18 male) suffering of spondylolisthesis were reduced by transpedicular instrumentation during June 2001 until October 2003. The cranial adjacent vertebra was temporarily instrumented and the reduction of the slipped vertebra was facilitated by the application of traction on the instrumentation leading to tension of the longitudinal ligaments. Posterior transforaminal lumbar interbody fusion (TLIF) or anterior lumbar interbody fusion (ALIF) was then carried out according to the degree of degenerative shortening of the anterior long. spinal ligament. On the last follow up (average 32 month postoperatively; min.: 22 month) both the reduction of the spondylolisthesis and the ossification of the interbody fusion was evaluated radiologically. Physical function and patients satisfaction was measured by means of the SF 36 questionnaire. RESULTS: The dislocation was reduced in all cases (81% on average). At the time of the last follow up bony fusion was depicted on the radiographs in all 32 patients. A distinct improvement in all categories of the SF 36 (in 5 out of 8 categories statistic significant) could be demonstrated. CONCLUSION: Temporary intraoperative instrumentation of the cranial adjacent segment proofs to be a simple an effective method for the sufficient reduction of spondylolisthesis.

Adult↗
PubMedDate not supplied

[Diagnosis of coxitis fugax, the most frequent hip disease in childhood].

After a review of the history, clinical features, laboratory findings, imaging techniques and the treatment of coxitis fugax, the authors inform about 131 own cases. In this disease of the hip joint, which is most commonly encountered in childhood, differential diagnosis is of the utmost importance. In the present study, the initial diagnosis had to be changed in eleven cases affected with this condition, which is also referred to as "observation hip". The patients ultimately contracted severe diseases such as leukaemia, juvenile polyarthritis or Perthes' disease.

Anti-Inflammatory Agents↗