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Biomedical subjects

C Bonnard

Publications and source records attributed to C Bonnard.

At least 37 records · Page 2Linked to original sources
PubMed1995

Restoration of hand function after brachial plexus injury.

Brachial plexus injuries effect hand function in different ways. Deficits may resemble those of a radial nerve palsy or those of an associated, high medioulnar paralysis. Analysis shows that active extension of the wrist is paramount in all procedures to gain quality results.

Brachial Plexus↗
PubMed1994

Optimal sequence and structure of iron-responsive elements. Selection of RNA stem-loops with high affinity for iron regulatory factor.

Iron regulatory factor (IRF) is a cytoplasmic mRNA-binding protein with specificity for iron-responsive element (IRE) RNA stem-loops. IRF post-transcriptionally regulates intracellular iron levels via binding to IREs in the untranslated regions of ferritin, transferrin receptor, and erythroid 5-aminolevulinic-acid synthase mRNAs. Specific IRE nucleotides are phylogenetically conserved: those of the 6-base loop (5'-CAGUGN-3') and an unpaired "bulge" cytosine. We prepared a pool of 16,384 IRE molecules randomized at these seven nucleotide positions and employed in vitro selection to identify RNAs that bind human IRF. Two major classes of high affinity RNA ligands were selected; the optimal loop sequences of each are 5'-CAGUGN-3' (wild type) and 5'-UAGUAN-3'. This novel finding predicts base pairing within the IRE loop between positions 1 and 5, thus facilitating the formation of a specific loop structure in which nucleotides at positions 2-4 are made accessible for protein interaction. Nucleotide substitution at these loop positions, or at the position of the bulge cytosine, decreased binding by 36-99%. In addition, we demonstrate a preferred IRE bulge structure and report a striking difference in the RNA binding specificity of rat IRF compared with that of the related IRE-binding protein, IRFB.

Animals↗
PubMed1994

[Epiphyseal separations of the knee].

Basic principles of treatment of distal femoral and proximal tibial growth plate injuries are described in relation to the anatomical lesions using the Salter-Harris classification. Some strategic recommendations are made for complex fractures: the articular surface must first be reconstructed followed by the metaphysis if possible.

Adolescent↗
PubMed1993

[Palliative treatment of myopathies. Contribution of surgical treatments].

The knowledge acquired over the last few years on Duchenne's muscular dystrophy (DMD) serves as the basis for management of all types of myopathy. After reviewing the current classification of muscle dystrophies and the principles of orthopedic management of these conditions, a historical perspective of surgical procedures used in DMD is presented. The various modes of discovery of myopathy are described. Deformities of the limbs and spine related to DMD are reviewed and their outcome is detailed. In DMD patients, the surgical procedures described allowed to delay loss of the ability to walk by 1 year 7 months to 3 years 8 months according to the severity of the condition, and provided significant improvements in quality of life. Surgical stabilization of the scoliosis ensured preservation of comfortable sitting in every case, as well as preservation of autonomous upper limb motion, with a low rate of complications. Surgical indications in DMD are well-established and serve as the basis for making surgical decisions in the other myopathies, except during early infancy. The principles and orientations of treatment of the other myopathies are defined, in the light of the variability of lesions and of the rate of muscle function loss. In these non-DMD myopathies, medical and surgical treatments are of as yet unquantifiable benefit but provide a substantial improvement in quality of life.

Adolescent↗
PubMed1993

Limb lengthening in children using the Ilizarov method.

By limb lengthening with the Ilizarov method on 24 children with an average age of 11 years, the average lengthening was 50 mm. The results were judged by the healing index and the corticotomy index. The average time for lengthening was 50 days. The healing index was on average 35 days per centimeter. Five complications were noticed during the first stage of the surgical procedure. During the lengthenings, eight cases of joint stiffness were observed, and in five normal biomechanical axes of the limb were modified. Only one abnormal biomechanical axis was perfectly corrected of eight present before surgery. There were three wire-tract infections. Only 13 of 26 patients were without any complications. The Ilizarov method had a lower rate of complication than the Wagner technique, however. Open corticotomy, as modified by De Bastiani, may accomplish lengthenings with somewhat fewer complications.

Biomechanical Phenomena↗
PubMed1992

[Experimental study of primary fixation of screw-ring acetabular components. Role of initial screw-cutting].

Three types of screw-ring acetabular components were implanted to determine the characteristics of their holding power and to study the influence of screw-cutting. The acetabular components were screwed into vinyl polychloride foam. Their resistance was measured. The optimal value of the locking screw couple and the value of the couple beyond the one at which the acetabular component loosened were determined. One of acetabular components was screwed in with and also without preliminary screw-cutting. Its resistance to wrenching was measured in both situations. The resistance curve at wrenching was characteristic of each screw-ring acetabular component. The resistance to wrenching was significantly higher (p < 0.01) for a given acetabular component if it was screwed into a largely open block of foam at its bottom. The screw-cutting allowed for a significantly higher resistance to wrenching (p > 0.05). It allowed for the screwing in with the least effort and for a better perception of the tightening. Knowledge of the comportment of screw-ring acetabular components once installed, usage of preliminary screw-cutting and recourse to a dynametric key are the means of improving the installation of screw-ring acetabular components.

Acetabulum↗
PubMed1992

[Carpal tunnel syndrome].

The carpal tunnel syndrome is very frequent. The authors insist on some points of surgical technique. The results of a Swiss study on the problem of the recurrent carpal tunnel syndrome are described (96 cases); the etiology of the recurrency, the surgical technique and the results after operative revision are analysed.

Carpal Tunnel Syndrome↗
PubMed1991

Late lesions of the brachial plexus after fracture of the clavicle.

Fractures of the clavicle, particularly those which are markedly displaced, may, in rare instances cause injury to the subclavian vessels and the brachial plexus which manifest progressively days or weeks after the initial trauma. More often than not, however, a costo-clavicular compression syndrome appears months or years after the clavicular fracture as a result of constriction by scar which invests the neuro-vascular bundle, by a secondary aneurysm or by hypertrophic callus. The authors report 16 such cases, one of which was treated conservatively, thirteen treated by surgical intervention while two cases are awaiting operation. These patients represent just over 1% of brachial plexus lesions seen over a period of twenty years in two surgical centres. Operative treatment consists of reduction of the clavicular deformity, possibly first rib resection, liberation of the plexus and correction of a vascular lesion as required. The outcome is usually good.

Adolescent↗
PubMed1991

[Surgery of the lower limbs in Duchenne's muscular dystrophy].

Seventy-one children had surgical procedures on hips and/or knees and/or feet contractures before or after the age of loosing gait. Gait has been continued on 1 year and 7 months to 3 years and 8 months according to the evolving type of Duchenne Muscular Dystrophy (DMD). After analysis of results of the surgery upon contractures, surgical procedures have been determined for each joint. Before loosing gait, but when contractures were all present, surgery prolonged on gait without orthosis and relieved of physiotherapy. During the 6 months after loosing gait, surgery allowed to recover same walking ability more often with orthesis. After loosing gait, surgery gave a better comfort of life to the child and his family.

Child↗
PubMed1991

[Reinhardt-Pfeiffer mesomelic dysplasia or dyschondrosteosis? Is the distinction well-founded? Apropos of a familial case with variable expression].

A familial observation of Reinhardt-Pfeiffer type mesomelic chondrodysplasia spanning three generations is reported. This case clearly shows that expression of the disease can vary widely within a given family. One member affected as a fetus had a severe form suggesting Langer mesomelic dwarfism syndrome, whereas his mother was free of clinical symptoms and his maternal aunt had a typical form of Reinhardt-Pfeiffer syndrome. Clinical manifestations in the other affected family members were perfectly consistent with dyschondrosteosis syndrome. The very broad spectrum of clinical patterns in this family suggests that there may be connections between the various types of mesomelic dysplasia. Establishing clear-cut distinctions between these entities, although useful in practice, may not accurately reflect molecular anomalies. Furthermore, the family member affected as a fetus also had Turner syndrome, which may have contributed to the severity of his condition. The possibility of identifying severe mesomelic dysplasias antenatally by ultrasonography should be pointed out.

Acrocephalosyndactylia↗
PubMed1990

[Patellar instability in children. Result of transposition of the medial third of patellar tendon].

Before bony maturity, the treatment of the recurrent dislocation of the patella is based on tendinous transfers. These distal procedures were often combined with proximal procedures on the medial or lateral patellar retinaculum and vastus medialis muscle. For the purpose of analysing efficacity of the medial third tendon transfer to the distal and deep part of the medial collateral ligament before the bony maturity, 24 children have been reviewed with a post operative follow up of 14 months to 6 and half years. There were 4 boys and 20 girls between 7 to 15 years old at the time of surgery. The troubles duration before the operation was from a few days to 4 years and the pathology was very often bilateral (40 knees). The recurrent dislocation of the patella was present 6 times, an instability 25 times and a traumatic dislocation 9 times. The technical procedure was every time a stabilisation with the transfer of medial third of the patellar tendon, associated except in 6 cases with a correction of the patellar motion by patellar retinaculum plasties. The functional result has been evaluated according to the sport activity and the ordinary life, with very hard criteria according to patient's age. Twenty-four times the result was excellent (60 per cent), 8 times good (20 per cent) and fair 8 times. Two complications have been observed. The improvement of the trochlea angle, and the trochlea deepness have been significant. Sixteen patients (27 knees) have been reviewed after the bony maturity and no growth disturbance of the tibial tuberosity has been observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Osteoarthritis of the hip in children. Proposal for a classification of sequelae guiding therapeutic indications].

Twenty-six hips in 21 patients were available at mean follow up of 5 years in a retrospective functional and radiographic analysis for the purpose of examining the late effects of infantile septic arthritis. Poor results after reconstructive efforts following hips joint sepsis suggest help classification of bony deformation. Epidemiologic and clinical findings were analysed. Late diagnosis and prematurity were found as poor forecast facts.

Acute Disease↗