The use of a biocompatible orthopaedic polymer in the treatment of loose total hip prostheses.

Seventeen cases of loose total hip prostheses were treated with biocompatible orthopaedic polymer, an osteoconductive co-polymer. Biocompatible orthopaedic polymer permits improved stability and secondary bone repair and may also act as a vehicle for adjunctive antibiotic therapy. The available forms of biocompatible orthopaedic polymer and their methods of application are described and the results obtained with their use are compared with the pre-operative clinical observations. Of the 17 patients studied, pain disappeared in 14, unlimited walking became possible in seven, while another eight patients were subsequently able to walk for over 300 m. Mobility became normal in 13 cases; full weight bearing on one leg became possible in 12 cases and became normal in another four. Radiological examination showed the development of a bony interface between the cortex and the prosthesis as the radiolucent biocompatible orthopaedic polymer material was converted into bone. It may, therefore, be concluded that, in this indication, biocompatible orthopaedic polymer appears to be an active interface for stabilizing loose total hip prostheses.

[Direct osteosynthesis of fractures of the odontoid process using a biodegradable implant (B.O.P.)]. / Ostéosynthèse directe des fractures de l'odontoïde par un implant biodégradable (B.O.P.).

The authors describe a new technique for treatment fractures of the dens. An anterior approach (technique of Boehler) is used. It provides for one-stage fusion and no additional disturbance of C1-C2 rotation. Under AP and lateral guidance the body of C2 is drilled medially, and so are the site of fracture. Then comes the gradual impaction of a conical implant of biocompatible resorbable implant [*], tip cephalad. The biopolymer is used for grafting purposes in all type of fractures of the odontoid process, which permits the latter to be fused without using screws or any other metal implant.

Chemical and physicomechanical aspects of biocompatible orthopaedic polymer (BOP) in bone surgery.

The properties of biocompatible orthopaedic polymer developed as an alternative to the metallic materials used in reconstructive bone surgery are discussed. Experiments were conducted to enhance the mechanical characteristics of the polymer by incorporation of various fibres. The result was a super biocompatible orthopaedic polymer which could be a valuable alternative to intra-medullary long bone metallic rods, whilst normal biocompatible orthopaedic polymer is currently used for bone filling and reconstructive surgery.

Use of biocompatible orthopaedic polymer for fracture treatment and reconstructive orthopaedic procedures.

For many years attempts have been made to develop materials for use in the surgical treatment of fractures. So far only metal implants have been used. Soviet research has now succeeded in developing a copolymer of polyvinyl-pyrrolidone and methyl methacrylate reinforced by polyamide fibres and calcium gluconate which is reported to have comparable strength of metal implants but superior flexibility. It can be trimmed and shaped at the time of surgery, has no irritative reactions or release of toxic components, and above all is biocompatible. Clinical studies have been going on for 10 years in various Soviet medical centres and the total number of cases treated with the biocompatible polymer implants is well over 1000. In no case was a repeat operation necessary to remove the implant. Control X-rays (as well as animal data) showed that biodestruction of the implants is complete within 1.5 to 3 years depending on their sizes. The first operations outside the Soviet Union have been recently performed in Belgium. In the Soviet Union this material has also been used to treat pathologic fractures and in reconstructive surgical procedures such as leg lengthening.

Effect of piracetam on extrapyramidal side effects induced by neuroleptic drugs.

In a double-blind crossover placebo controlled trial the effectivity of piracetam in neuroleptic-induced extrapyramidal side effects was confirmed. 40 psychotic patients treated with neuroleptics in an average daily dose equal to 600 mg of chlorpromazine were included in this study. Akathisia, tremor, muscle rigidity and dyskinesia were evaluated on a 4-point scale. The patients were randomly divided into two subgroups--40 g of piracetam or placebo from identic ampoules were given i.v. with a crossover readministration after 60 min. The intensity of the extrapyramidal side effects was evaluated at 30-min intervals during 2 h. Piracetam was proved to be significantly effective in both subgroups, the onset of its action being between 30 and 60 min after i.v. administration. Possible interpretations of the observed piracetam effectivity are considered. Further trials with piracetam in neurologic complications during neuroleptic treatment, tardive dyskinesia included, are suggested.

The role of mesna in the treatment of status asthmaticus in children.

Status asthmaticus in children is a life-threatening condition that calls for a comprehensive set of therapeutic measures, viz. evacuation of tracheobronchial secretions, parenteral drug administration and improvement of alveolar gas exchange. In the authors' experience, that therapeutic procedure can be much improved by bronchial lavage with mesna. This is illustrated by the good results obtained in fourteen patients with status asthmaticus and in another forty-four cases of global respiratory insufficiency. Evaluation was by blood gas values and X-ray pictures. The method used for bronchial lavage is described.

Biological correlates of piracetam clinical effects in psychotic patients.

The purpose of this controlled clinical trial was to demonstrate possible correlations between changes in bioenergetic metabolism and psychotropic drug administration in the treatment of functional psychosis. The study included twenty-six patients, eleven with schizophrenia, three with chronic atypical depression and twelve with drug-resistant endogenous depressions. All patients were kept on continuous psychotropic medication for at least 3 weeks before starting the trial, and piracetam was given additionally in a fixed dosage of 2400 mg daily; the same number of identical capsules was given during the pre- and post-treatment placebo periods. Psycho-pathological evaluation of the patients was by the BPRS; clinical and biochemical data were evaluated statistically by the analysis of regression. The results show that in schizophrenic patients an improvement was observed in those cases who had improved biochemically, i.e. where the ATP values had increased. In drug-resistant depressions there was a rapid and significant clinical improvement after piracetam co-administration, and this went in step with a significant rise in ATP levels.