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Biomedical subjects

F U Niethard

Publications and source records attributed to F U Niethard.

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

[Effect of risk factors and therapy on intermediate-term hip deformity in Perthes disease].

UNLABELLED: The prognostication of risk factors for the outcome of LCPD was examined. The radiographic results of conservative treatment with Thomas splint and operative treatment with intertrochanteric derotational varus osteotomy (DVO) were compared using the Index of Deformity (D). METHOD: Radiographs of 153 patients with unilateral LCPD were evaluated retrospectively 1.5-3 years and 3-7 years after diagnosis using the Index of Deformity and Index of Direction. We investigated the radiographic changes in relation to acetabular or metaphyseal reaction, Waldenström classification or limited range of motion at diagnosis and in dependence of therapy. RESULTS: There was a significant better acetabulum-head-index of deformity after DVO. Children with metaphyseal or acetabular reaction had bigger deformities. Patients with metaphyseal reaction had smaller deformities after DVO compared with conservative treatment. Free range of motion (ROM) was prerequisite for good results after DVO. Waldenström classification at diagnosis did not have any influence on morphologic changes after 3-7 years. CONCLUSION: DVO leads to a better containment than conservative treatment with Thomas splint, metaphyseal reaction should be an indication for operative treatment. Prerequisite for DVO is a free ROM. Because Waldenström class at diagnosis does not influence the outcome, free ROM before starting the treatment is more important than an immediate start of therapy.

Adolescent↗
PubMedDate not supplied

[Optimizing the bone cement-implant interface by hydrolysis-resistant conditioning of the metal surface].

PURPOSE: The hydrolytic degradation of the implant-cement interface has to be seen as the main reason for aseptic loosening of cemented total hip replacements. Therefore, a new method of conditioning the metallic surface was developed in order to achieve a hydrolytic-resistant bound stability between the implant and bone cement. Preliminary experimental data on test bodies are presented here. METHOD: The metallic surface of 6 pairs of cylindrical test bodies each (CoCr-alloy, circular testing surface with O 6 mm) were conditioned by the method of silicoating/silanisation to gain a covalent coupling with the applied bone cement. In order to examine the initial stability and the hydrolytic resistance of the metal-cement compound, these pairs of surface-conditioned test bodies (SCT) as well as a reference series of surface-unconditioned test bodies (SUT) were immersed for 0, 30, 90, 150 days (d) in moisture environment (physiological saline solution, 37 degrees C) after coupling with bone cement. The adhesive strength of the test bodies-(bone cement-compounds) were determined by tensile tests on an universal testing machine (Typ Z030, Zwick, Ulm) with gimbal suspension. RESULTS: At time 0 d (that was without immersion of the test bodies) the mean maximum tensile bond strength of the SCT-cement-compounds was 39.5 MPa (SD +/- 4.7 MPa) and that of the SUT-cement-compounds 37.1 MPa (SD +/- 7.3 MPa) (p = 0.575). After immersion the tensile bond strength of the SUT-cement-compounds significantly decreased to an average of 13.5 MPa (SD +/- 2.7 MPa) (30 d), 10 MPa (SD +/- 1.7 MPa) (90 d) and 12.3 MPa (SD +/- 1.4 MPa) (150 d) (p < 0.01). In contrast, the SCT-cement-compounds showed a nearly unchanged high mechanical stability with tensile bond strength values of 37.0 MPa (SD +/- 4.9 MPa) after 30 d, 36.1 MPa (SD +/- 5.0 MPa) after 90 d und 30.2 MPa (SD +/- 4.7 MPa) after 150 d (p > 0.01). CONCLUSIONS: With reservation as to further in vitro and in vivo investigations the increased hydrolytic stability of the metal-cement-bound of surface-conditioned CoCr-alloy test bodies promises an improvement of the long-term stability of cement total joint replacements.

Arthroplasty, Replacement, Hip↗
PubMedDate not supplied

[Modification of bone quality by extreme physical stress. Bone density measurements in high-performance athletes using dual-energy x-ray absorptiometry].

The treatment of osteoporosis is still controversial. Rehabilitation programs which stress strengthening exercises as well as impact loading activities increase the bone mass. On the other side activity level early in life has not been proven to correlate with increased bone mineral content later in life. Little is known on the influence of high performance sports on the bone density especially in athletes with high demands on weight bearing of the spine. In (n = 40) internationally top ranked high performance athletes of different disciplines (n = 28 weight-lifters, n = 6 sports-boxers and n = 6 bicycle-racers) bone density measurements of the lumbar spine and the left hip were performed. The measurements were carried out by dual-photonabsorptiometry (DEXA; QDR 2000, Siemens) and evaluated by an interactive software-programme (Hologic Inc.). The results were compared to the measurements of 21 age-matched male control individuals. In the high performance weight lifters there was an increase of bone density compared to the control individuals of 23% in the Ward's triangle (p < 0.01). The sports-boxers had an increase up to 17% (lumbar spine), 9% (hip) and 7% (Wards' triangle). In the third athletes group (Tour de France-bikers) BMD was decreased 10% in the lumbar spine, 14% in the hip and 17% in the Wards' triangle. Our results show that training programs stressing axial loads of the skeletal system may lead to an increase of BMD in the spine and the hip of young individuals. Other authors findings, that the BMD of endurance athletes may decrease, is confirmed. Nevertheless the bikers BMD-loss of 10 to 17% was surprisingly high.

Absorptiometry, Photon↗
PubMedDate not supplied

[Intra-articular oxygen partial pressure measurements under functional conditions].

Oxygen partial pressure is directly related to the vascularisation of different tissues. Different investigations in tissue (muscle, kidney, brain, heart, bone etc.) proved this correlation. The development of a special flexible microcatheter named Licox enables us to do measurements of intraarticular oxygen partial pressure under physiological and pathological conditions for the first time. The aim of this study was to examine the influence of different knee joint stresses on the intraarticular oxygen partial pressure under normal conditions and in osteoarthritis. The results showed that the different exercise patterns influence the intraarticular oxygen partial pressure. Patients with osteoarthritis showed a lower increase of the intraarticular oxygen partial pressure compared to the control group. This phenomenon is directly correlated to degree velocity of the isokinetic exercises. The same findings occur under ergometric conditions. The method permits functional, intraarticular in vivo measurements under different exercise patterns. For the very first time we were able to measure the influence of the joint movement on the intraarticular process of nutrition under physiological and pathological conditions. Different therapy concepts in osteoarthritis can be evaluated directly in vivo for the first time.

Adult↗
PubMedDate not supplied

[Primary correction of scoliosis with the Wilmington corset].

QUESTION: As part of our study, the effectiveness and patient's acceptance of the Wilmington-brace is to be evaluated. The effectiveness can be documented with the help of the primary correction achieved, especially in light of the fact, that the primary correction and the long-term results are directly dependant upon one another. MATERIAL AND METHOD: We examined a total of 52 patients with an idiopathic scoliosis treated in a thermoplast brace. The group consisted of 38 female and 14 male patients (average age 11.6 years). The angulation was measured with the help of the Cobb-angle and the rotation with the method described by Nash and Moe. The skeletal age was classified according to Risser's-sign. The angle determinations were carried out at three separate points in time--at first presentation, prior to bracing and four to six weeks following bracing. RESULTS: The patients presented with an average angulation of 31 degrees. The average correction achieved in the Wilmington-brace was 41%. This corresponds to a correction of 13 degrees. The best primary correction (45%) was obtained in the thoracolumbar spine. Those patients with the smallest deformity at the onset of treatment showed the best results. The scoliosis with a large primary deformity and a marked rotation of the vertebral bodies responded poorly to correction. Advanced age or skeletal maturity were also limiting factors. Physical therapy had a positive influence on the amount of primary correction obtained. CLINICAL RELEVANCE: The Wilmington-brace (thermoplast) allows for a good primary correction of idiopathic scoliosis. The simplicity of application and the low production costs are also positive attributes.

Adolescent↗
PubMedDate not supplied

[Etiology, diagnosis and therapy of aseptic hip prosthesis loosening--a status assessment].

PURPOSE: Aseptic loosening of prostheses implants is the most common complication of hip replacement surgery and represents an increasing problem because of still rising numbers of primary arthroplasties. This study reviews the current scientific status of causes, diagnosis and therapeutical concepts on this theme in literature. METHOD: We analyzed 6,386 cases on aseptic hip revision arthroplasties published in the international literature and separated the results for cup and femoral components. On this basis we deduced some recommendations for the operative procedure in aseptic hip revision surgery. RESULTS: The mean follow-up time of all studies was 6.8 years in the case of cemented and 4.0 years in the case of uncemented hip revision arthroplasty. As an average rate of rerevision, 15.1% was calculated for cemented cup revisions, 4.3% for uncemented cup revisions. Rates of aseptic loosening were 23.1% for cemented procedure, 8.8% for uncemented cup implants. Femoral revision implants showed an average aseptic loosening rate of 21.2% for cemented procedures and an average rate of rerevisions of 12.7%; uncemented procedures showed aseptic loosening in 4.4% of the cases and rerevision in 5.5%. For old, relatively immobile patients with reduced physical constitution, cemented reimplantation has still to be regarded as the method of choice. In young patients uncemented revision arthroplasty is to prefer both on the acetabular and the femoral side to achieve superior results with good long-term prognosis. Regarding the bony defects induced by loosening, bone grafting is recommended for cemented and uncemented reimplantation technique. CONCLUSION: In the case of aseptic hip revision arthroplasty, the therapeutical procedure has to be adapted especially to the age and general constitution of the patient as well as to the bony defects induced by prosthetic loosening. For the future, controlled studies should respect the initial condition of primary as well as revision arthroplasty in reporting the results.

Hip Prosthesis↗
PubMedDate not supplied

[Use of new biochemical markers in diagnosis of aseptic hip endoprosthesis loosening].

Aseptic loosening of endoprosthesis is the most important problem in total hip arthroplasty. The diagnosis of aseptic loosening is based on anamnesis, the clinical findings, the radiography and scintigraphy. Despite the multitude of diagnostic possibilities it is still a problem to get an exact and early diagnosis. The process of loosening in the bone interface always leads to a change of bone structure of the surrounding bone tissue. In a prospective study we measured biochemical markers of bone metabolism in serum and urine to evaluate a possible change occurring parallel to endoprotheic loosening. 37 patients with severe signs of loosening (later intraoperatively confirmed) and 30 patients without any clinical or radiological signs of loosening (control group) were induced. Gender, age and model of endoprosthesis were similar in both groups. Parameters of bone formation (osteocalcin, alkaline phosphatase, procollagen I C-terminal extension peptide) and bone resorption (Cross-linked n-terminal telopetide) were measured. The cross-linked n-terminal telopetide (NTX) was significant increased in the loosening group (p < 0.001). Of the measured bone formation markers only osteocalcin showed a significantly higher level in patients with endoprosthetic loosening (p < 0.002). All other measured parameters of the bone metabolism showed no significant differences between the both groups. Our results show, that biochemical markers can provide relevant information of endoprosthesic loosening. We are now analysing in a prospective longitudinal study whether these parameters are also suitable to detect early endoprosthetic loosening.

Adult↗
PubMedDate not supplied

[Mechanism of action of hyaluronic acid in gonarthrosis of both knee joints in a right/left comparison. Study with dynamometry, oxygen partial pressure, temperature and Lequesne score].

In a controlled prospective randomized study we evaluated the effectiveness of intraarticular injected hyaluronic acid regarding the changes in the parameters dynamometry, synovial oxygen partial pressure, intraarticular temperature and the knee joint function (Lequesne score). We examined 18 patients with osteoarthritis in both knee joints (Kellgren classification II or III according to x-ray) in right/left comparison. The evaluated parameters were measured before and after a 5-week treatment phase with 5 intraarticular injections (one injection per week). With regard to the efficacy results changes in dynamometric measurement for flexion and extension (for all angular velocities) and Lequesne-score indicate a marked improvement after treatment with hyaluronic acid. The differences between treated and untreated knee were significant. In extension the p-value was 0.0008 and in flexion p = 0.0015. The p-value of the Lequesne-index between the verum and control group was p = 0.0002. After treatment values for oxygen pressure were higher than at baseline and for the intraarticular temperature a small decrease at the end of the treatment phase was documented. The intraarticular injection of hyaluronic acid is effective and safe in the treatment of patients with gonarthrosis. The treatment resulted in a functional improvement of the knee joint and had a good pain-lowering effect in patients suffering from gonarthrosis.

Aged↗
PubMedDate not supplied

[Complete synostosis of the cervical spine at a young age. A thus far unpublished disease].

A case of complete synostosis of the cervical spine in a 12-year-old girl is described. Differential diagnosis included dysontogenetic forms of synostosis, Klippel-Feil syndrome, rheumatic synostosis and synostosis of other inflammatory origin. This severe case, the first of its type to be described, appeared to be due to tuberculosis of the cervical spine.

Cervical Vertebrae↗
PubMedDate not supplied

[Demonstration of the blood supply of human cruciate ligaments using the plastination method].

The blood supply of the attachment regions of the anterior and posterior cruciate ligament is demonstrated in 14 cadaver knees by the plastination method. Our findings demonstrate the blood supply by vessels of the synovium. The direct attachment to the bone is free of vessels. Anastomoses between the synovium and the periosteum could be found. In conclusion the surgical coverage of ligament reconstruction and of ligament transplantation by synovium is recommended when ever possible to permit the ingrowth of revascularisation vessels.

Adult↗
PubMedDate not supplied

[Development of paralytic scoliosis in myelomeningocele].

Among other things the probability of developing a scoliosis in myelomeningocele depends on the patients age, the neurological level of lesion and the localisation of the vertebral arch defect. This study tries to analyse the influence of these factors in 465 patients with MMC and paralytic scoliosis. The results show, that the patients age and the neurological level of lesion are the most important factors for the development of paralytic scoliosis. The statistical evaluation based on the data found permits the determination of regression lines, which allow an estimation of further progression of paralytic scoliosis with respect to the neurological level of lesion and the patients age. At levels of paralysis between Th 3 and Th 12 an average progression of 3.5 degrees per year can be expected. Between L 1 and L 3 the progression rate can be estimated to be 2.5 degrees per year. At levels of paralysis distal to L 3 one can expect to find no significant development of scoliosis. In cases, which exceed the prediction interval, additional intraspinal anomalies, i.e. syringomyelia, must be considered and further examinations including MRI are required.

Adolescent↗
PubMedDate not supplied

[Patellar hypertension syndrome--nomenclature, diagnosis and therapy].

PURPOSE: Complaints in the area of the patella have been abundantly described in the literature. However, a uniform nomenclature with regard to either diagnosis or therapy does not exist. METHODS: With the help of a standardized measuring method (intrapatellar pressure measurement and provocation test), it is possible to describe and classify patellar pain. An intrapatellar pressure increase over 25 mmHg and/or a positive provocation test defines the term of Patella Hypertension Syndrome. RESULTS: Within a prospective study we carried out a special intraosseous drilling in 20 cases with the typical symptoms of the Patella Hypertension Syndrome. The drilling, which was carried out via the Hoffa fat body from distal, resulted in a distinct alleviation of symptoms in all cases and even in a complete absence of pain in most cases. This phenomenon was objectified by a pressure-check-up after 6 weeks, 6 months and 1 year following the drilling. In all 20 cases so far examined a decrease of between 40-70% of the original pressure level was achieved. In all cases the postoperative artificial pressure increase (provocation test) of the intraosseous pressure did not lead to the typical pain symptoms. CONCLUSION: We therefore have a relatively minor operation at our disposal enabling us to achieve an impressive therapeutic success, in cases where conventional treatment was neither causal nor successful.

Adolescent↗