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Biomedical subjects

L Zichner

Publications and source records attributed to L Zichner.

63 records · Page 4Linked to original sources
PubMedDate not supplied

[Studies of explanted shot-peened osteosynthesis plates].

Shot peening is a cold-working process to increase the fatigue life of osteosynthesis plates. Using ceramic particles for this process we observed no change in the corrosive properties of the plates. Up to now we implanted 37 shot peened osteosynthesis plates for fixation of intertrochanteric osteotomies. 13 plates were explanted after an average time of 14,2 months. We investigated the plates as well as the tissue surrounding the implants. Metallurgic specimens showed not so many pittings at the shot peened plates in the region of the screw hole as were seen at the polished plates after the same period of implantation. By histological investigation corrosive products or fretting particles were detected mostly in the region of the screws. Only a few metal particles were found in the region between the screw holes. Analysing the elements which were black or red-brown coloured in histological specimens by scanning electron microscopy we identified these particles as metal components. But there was a great difference in the relation of the particles found in the tissue compared to the components forming the plates alloy. This is due to the difference of distribution of the metal components at the surface of the implant in comparison with the central part of the plate. These austenitic stainless steels are protected by an enrichment of Cr in the surface layer. This could be shown in the shot peened plates as well as in the polished plates. The results of our investigations show a corrosive behaviour which is at least equal at both plates types in laboratory investigations as well as after implantations in men.(ABSTRACT TRUNCATED AT 250 WORDS)

Biomechanical Phenomena↗
PubMedDate not supplied

[Experiences with the operative therapy of osteogenesis imperfecta].

Osteogenesis imperfecta is one of the commonest congenital systemic diseases. The treatment of the fractures caused by the diseases and the growth deficiencies which result is mainly conservative. Taking 22 operations on patient suffering from osteogenesis imperfecta, the results of the treatment are reported and the cases in which an operation is indicated are discussed. As the osteosynthesis material selected, the intramedullary Rush pin has proved its worth. No serious complications were observed.

Child↗
PubMedDate not supplied

[Changes in the juvenile pelvis in congenital systemic diseases of the skeleton (author's transl)].

Constitutional disorders of the skeleton show a characteristic appearance in the radiogram of the juvenile pelvis. These radiologic changes are presented in tables and are discussed demonstrating individual cases. Because of the limited reactive possibility of the skeleton not every disorder shows a typical feature of differential diagnosis and radiologic pattern. To differentiate from the congenital dysplasia of the hip and Legg-Calvé-Perthes disease the distribution of the skeletal disorders and their course therefore have to be known. Accordingly the therapeutic consequences have to be drawn. In this purpose the radiologic diagnostics of the juvenile pelvis are of significant value.

Bone Diseases, Developmental↗
PubMedDate not supplied

[Artificial hip joint implantation in stiff-man syndrome].

UNLABELLED: AIM AND METHOD OF THE STUDY: The Stiff-Man syndrome is characterized by progressive, usually symmetric rigidity of the axial muscles of the trunk with superimposed painful spasms precipitated by various stimuli. The neurologic disorder of SMS is discussed with respect to its symptoms of orthopedic interest including treatment modalities for total hip replacement. RESULTS: An increased incidence of hip disease in patients with SMS seems unlikely according to our analysis. CONCLUSION: SMS-patients should, however, be defined at risk for heterotopic bone formation following hip arthroplasty requiring a perioperative prophylaxis.

Adult↗
PubMedDate not supplied

[Value of glenoid osteotomy in treatment of posterior shoulder instability].

UNLABELLED: Purpose of this retrospective study was to evaluate the midterm results of glenoid osteotomy in the treatment of posterior instability and furthermore to evaluate the relevance of etiopathogenesis on the outcome. METHOD: Between Jan. 83 and May 94 32 patients underwent surgery due to posterior instability. Retrospectively these patients were classified based on their etiopathogenesis. 28 patients could be reexamined clinically and radiologically after and average of 4.85 years, of which 21 were treated with a glenoid osteotomy. For evaluation the Constant-Murley and the Rowe-Score were used. RESULTS: The Constant-Score showed 82,2% and the Rowe-Score 71,5% good or excellent results. Evaluation of glenoid osteotomy demonstrated for the patients with atraumatic genesis an excellent result in 76.9% with a recurrence rate of only 15.4%. On the other hand patients with traumatic instability showed a recurrence rate of 50%. The radiologic assessment demonstrated degenerative changes in nearly 30% of cases treated with glenoid osteotomy. CONCLUSION: This study shows that glenoid osteotomy can provide good result in the surgical treatment of posterior atraumatic instability. For treatment of traumatic instability, however, glenoid osteotomy is not the procedure due to high recurrence and arthrosis rates. RELEVANCE: Posterior glenoid osteotomy should be reserved for patients with atraumatic posterior instability combined with an increased retroversion angle of the glenoid especially because of the high rate of arthrosis.

Adolescent↗
PubMedDate not supplied

Repair of nonunions by electrically pulsed current stimulation.

Five congenital and 52 acquired nonunions of bone were stimulated using an invasive device. The unit delivered a constant but pulsed right-angled current of positive polarity measuring 20 to 25 muAmps (voltage of 750 mV) and a frequency of 20 Hz. The power pack encapsulated in epoxy resin was implanted at the time of operative fragment stabilization. THe cathode was inserted at the site of the nonunion gap. After two to 12 months, all but two of the acquired nonunions and one of the congenital pseudarthroses healed. In the unsuccessful cases, the bone ends were often totally necrotic. Four cases required reimplantation because of broken wires or expiration of the battery, and two cases failed owing to purulent infection. Electrostimulation is an adjuvant treatment to fragment stabilization in hyporeactive and hypovascular or congenital pseudarthroses. Electrical stimuli may be assumed to simulate conditions which are essential for bone healing.

Carpal Bones↗