Biomedical subjects

F Burny

Publications and source records attributed to F Burny.

At least 19 recordsLinked to original sources

PubMed2002

Analysis of the capital femoral line orientation. A CT scan study.

An accurate knowledge of the relationship between the neck and the epiphyseal plate at the end of growth is important for biomechanical investigations of femoral neck remodelling during childhood. Statistical data about the position of the epiphyseal femoral cartilage in relation to the neck axis at the end of the growth, are rare in the literature. As the trace of the epiphysis can be observed on a CT scan view of an adult hip, cadaver femurs were investigated to study this relationship and to avoid irradiation of children. The mean anteversion angle of the epiphyseal line towards the patient's coronal plane is 2.3 degrees. The plate is retroverted in an average of 8.2 degrees in relation to the neck axis and is related to neck anteversion. The more the neck is anteverted, the more the plate is retroverted.

Femur↗

PubMed2002

Theoretical study of the decrease in the femoral neck anteversion during growth.

This theoretical analysis tries to explain the decrease of the femoral neck anteversion during growth according to well-established concepts. In the frontal plane, it was demonstrated that the capital epiphyseal plate inclination allows the plate to remain perpendicular to the resultant force applied to the hip during gait. In the transversal plane, the projection of this force varies from -24 degrees, outwards and forwards (heel strike), to 20 degrees, outwards and backwards (toe off). A mathematical formula calculates the instantaneous coordinates of the plate in this plane during gait. This kinematic study points out that the physiological value of the capital epiphyseal plate anteversion at the end of the growth is theoretically the ideal value to obtain in the transversal or horizontal plane a perpendicular relation between the orientation of this plate and the projection of the resultant force during walking.

Biomechanical Phenomena↗

PubMed2002

[The orthopedics-traumatology department].

The Department is involved in clinical and research activities. We pioneered the clinical application of "smart of Orthopaedic implants". The monitoring concept, bringing a high added value, helps in assessing fracture healing or implant fixation. The technique, featuring the 21st century, also requires advanced knowledge in biomaterials. Such implants have been used during the ESA Parabolic Flight Campaigns. These measurements are a prerequisite to establish prevention programs of the bone demineralisation during space flights but also in disuse osteoporosis. The Department is deeply involved in external fixation. In vitro studies of the mechanical insertion and holding parameters of external fixation pins have been performed to produce new implants, which efficiency has been proved by a clinical study. We defined original clinical principles of external fixation as its use in upper limb indications, to maintain microsurgery transplant, preserving devascularization and providing adequate fixation. Our biomechanical approach of the upper limb, now confirmed by others research groups, questioned old clinical concepts. The isokinetic evaluation assesses the dynamic function of articulations, i.e. after arthroplasty, and is also used for medico-legal evaluation. The clinical research touches orthopaedic (or systemic) diseases as algodystrophy, Kienböck disease, Kashing Beck. We conducted a multidisciplinary research on the effect of electromagnetic fields (EMF) on cells differentiation. In addition to possible healing properties, it helps as an objective support to analyse the exposure to the environmental EMF.

Belgium↗

PubMed2002

[Orthopedic immobilization].

The classical plaster bandage was devised in the mid 19th century. Until recently, osteoarticular trauma has been treated mostly by plaster cast immobilisation using plaster of Paris. Synthetic materials have been introduced on the market place in the seventies, but they have not superseded the traditional plaster of Paris. The more recent thermoplastic materials are used to make splints and orthoses, particularly at the wrist and hand. The present review of the literature confirms that synthetic materials present better physical and mechanical properties than the traditional plaster of Paris. In addition, they are lighter, they are more resistant to humidity, they are more radiotransparent and they generate less dust when removed. However, they are less malleable and cause higher pressure in case of limb edema. Plaster of Paris therefore remains indicated in the acute posttraumatic or postoperative period. This material is also cheaper, but the pecuniary benefit is limited for several reasons, particularly because plaster of Paris is associated with a higher rate of cast replacement.

Casts, Surgical↗

PubMed2001

The vacuum phenomenon: a CT sign of nonunited fracture.

OBJECTIVE: The purpose of this study was to describe on CT scans the presence of a gas collection within a bone fracture reflecting the vacuum phenomenon as a sign of nonunited fracture. CONCLUSION: A gas collection between fractured bone fragments suggests a nonunited fracture.

Adolescent↗

PubMed2001

[Corrective osteotomy using Hoffmann II external fixators for extra-auricular malunion of the distal radius].

The authors present the technique and clinical results of a corrective osteotomy for malunion following extra-articular fractures of the distal radius. External fixation allows restoration of the length of the radius with minimal damage to the periosteum. It allows early mobilization of the radiocarpal joint. The position of the distal pins provides intraoperative visual control of the angular correction. The minimal invasive approach decreases the risk of iatrogenic lesion of an extensor tendon or a sensitive branch of the radial nerve. This technique is easy and reliable.

Adult↗

PubMed2000

Concept, design and fabrication of smart orthopedic implants.

Extensive clinical experience has been built up using orthopaedic implants instrumented with strain gauges connected to a Wheatstone bridge by means of percutaneous leads. This research showed the medical relevance of the monitoring of the deformation of implants as a powerful tool to evaluate nursing and rehabilitation exercises, for tracing dangerous overloads and anticipating implant failure and also to observe the healing process. The IMPACT 3500 project focuses on the instrumentation of femoral implants with on board sensors: regular Benoist-Girard implants have been modified, to contain a 'sensing cell', and thoroughly tested in vitro and in vivo. The implant deformations are measured with resistive strain gauges, and the signal is transferred to a personal computer for processing and display, via a hard wired connection, or via a telemetry system. Two fully implantable wireless designs, called Linkstrain and Sealstrain, are powered from the outside by magnetic induction. As Sealstrain contains the whole telemetric system in its cavity, the highest miniaturization was required; this seriously deteriorates the efficiency of the inductive power link.

Biocompatible Materials↗

PubMed2000

Geometrical analysis of the femoral neck torsion.

By the geometrical analysis of three cross sections the surface along the femoral neck, the second moments of area and the major axes of symmetry are obtained. The surface passing through these axes determined in each section, from the lateral to the medial third of the neck, is one of the two anatomical surfaces of symmetry of the neck. The geometric structure defined by this surface is a helicoid. No plane, in the ordinary sense of the word, has to be defined in the femoral neck. At the trochanteric junction, the major axis is inclined about 17 degrees on the anteversion plane, twists anteriorly and becomes more horizontal to finish with a mean inclination of 60 degrees at the cephalic junction. Surprisingly, this twist and then the neck torsion are in opposite directions to that suggested by the bony markers, often taken as a reference and reported in the anatomical descriptions.

Biomechanical Phenomena↗

PubMed1998

Tissues and bone adhesives--historical aspects.

Glues and adhesives attach to a surface principally involving molecular attraction, whereas cements mostly work through mechanical interlocking. The adhesive and its degradation products must be biocompatible: chemical, clinical, legal, physical aspects are considered; the toxicity of even minor components must be extremely reduced. The idea of bone bonding using biological materials has been proposed by Gluck, in Berlin, more than a century ago. Cements and adhesives have been used for the fixation of fractures, the repair of defects and the fixation of prostheses. The cements are initially liquid or plastic and conform with the irregularities in the substratum, producing better bonding on rough surfaces. Developed during the early 1950s, cyanocrylate adhesives attracted the medical community by their bonding strength and ability to bond in wet environments but reports of displacement of the fracture ends were followed by reports of high infection rates, nonunion, and severe local reactions. Polymethylmethacrylate does not form a chemical bond with bone but a mechanical bond, a weak bone-polymer joint. Charnley used self-curing acrylic cement to bond a femoral head prosthesis into a femur. When adhesives are used to bond tissues, the polymer acts as a barrier between the growing edges and delay healing; the adhesive tends to be rapidly isolated from the bone by a fibrotic, non-adhesive capsule. No proof exists concerning the osteogenic potential of fibrin sealing (FS); its beneficial effect on bone formation has been questioned even if there is some evidence that FS should influence the early phases of bone repair and may help to solve the problem of reattachment of small osteocartilagenous fragments following joint trauma.

Animals↗

PubMed1997

Lunatomalacia associated with congenital shortening of the ulna in Langer-Giedion syndrome: a case report.

A 22-year-old patient with type I trichorinophalangeal Langer-Giedion syndrome presented a stage 2 osteonecrosis of the lunate associated with congenital shortening of the ulna and carpal tunnel syndrome. The patient was treated by shortening osteotomy of the radius and median nerve neurolysis, with an excellent result. This case provides an additional piece of evidence associating ulnar-minus variance with lunatomalacia, and another argument in favor of the theory that Kienböck's disease results from microfractures sustained by the lunate under an abnormal stress distribution situation.

Abnormalities, Multiple↗

PubMed1997

Radiocarpal articular pressures during the reduction of distal radius fractures.

OBJECTIVES: To measure in vivo radiocarpal articular pressures during closed reduction and external fixation of distal radius fractures. DESIGN: Intraoperative measurements using a sterile pressure sensitive sensor specially constructed for this application. SETTING AND PATIENTS: Ten patients with a closed distal radius fracture stabilized by radiometacarpal external fixation. Radiocarpal pressures measured during transarticular distraction, wrist palmar flexion, wrist ulnar inclination, and fracture reduction. MAIN OUTCOME MEASUREMENTS AND RESULTS: Transarticular distraction resulted in a substantial decrease of the articular pressure, averaging -158.1 mmHg. Palmar flexion resulted in a mean pressure increase of 91.8 mmHg. The reduction of the fracture using a combination of distraction, palmar flexion and ulnar deviation resulted in either an increase or decrease of articular pressure, but always with a tendency toward progressive normalization of the pressure, with a mean slope of 3.2 mmHg/min. CONCLUSIONS AND CLINICAL RELEVANCE: The phenomena leading to the reduction of distal radius fractures could be related in part to a decrease of the intraarticular pressure, which may be responsible for a suction effect on the intraarticular bone fragments.

Adolescent↗

PubMed1997

Can algodystrophy be prevented after hand surgery?

Algodystrophy is characterized initially by an increase in arterial flow, an increase in blood pool, a decrease in microcirculatory velocity, and a loss of thermoregulatory control. These changes, producing the typical symptomatology, associated diffuse hand pain, diminished hand function, edema, and abnormal color and temperature, are believed now to correspond in most cases to an exaggeration of the normal post-traumatic inflammatory responses and are not the consequence of sympathetic damage. Algodystrophy may be prevented in most hand surgery patients by minimizing the normal postoperative inflammation, by increasing venous return (especially by avoiding plaster casts and constrictive dressings), by controlling post-traumatic pain, by promoting early active mobilization, and by reassuring the patient. If there is any sign of algodystrophy, three-phase bone scintigraphy should be obtained and treatment instituted immediately.

Arm↗

PubMed1996

Does the normal contralateral wrist provide the best reference for X-ray film measurements of the pathologic wrist?

This study compares in normal subjects the variability of wrist x-ray film measurements between the right and left sides with the variability of the distribution of those measurements within the population. Additional purposes were to evaluate possible differences of these measurements according to sex, age, side, and hand dominance. The variability when comparing both sides was found to be statistically less for the carpal height, radiolunate, scapholunate, and capitolunate angles than within the whole group of subjects, and for those measurements, there was a high correlation (r > .88) between the right and left sides. In addition, the carpal height and the carporadial ratios were lower and the capitolunate angle was higher in women than in men. There was also a significant decrease of the scapholunate angle in older individuals. The clinical implication of these findings is that in unilateral wrist diseases, the normal wrist should be used to provide the reference values of the carpal height and of the carpal angles on profile x-ray films. However, for the radial inclination and palmar tilt of the distal radius and for the ulnar variance, the normal side does not provide a better reference than normal values obtained from databases.

Adult↗

PubMed1996

[Treatment principles in hand fractures].

The fractures of the hand are frequent and represent a problem of public health. The displacement of the fracture occurs because of post-traumatic musculo-tendinous imbalance. The fractures of the hand are to be treated according to four principles: anatomical reduction, followed, when possible, by immediate mobilization, if necessary, by immobilization of the injured parts in the "protective" position (metacarpophalangeal flexion, interphalangeal extension and with the first web space under stretch), and prevention of post-traumatic edema. When an osteosynthesis is performed, the mounting should be stable enough to allow early mobilization. The most useful techniques include external minifixation, and internal fixation using one or several screws.

Bone Screws↗

PubMed1995

A biomechanical study of the ulnar nerve at the elbow.

The relative elongation with elbow flexion of the ulnar nerve, proximal and distal to the cubital tunnel, and of the cubital tunnel retinaculum, was measured in cadaver specimens by stereophotogrammetry. The proximal part of the ulnar nerve elongated significantly with full elbow flexion. No significant change of length was measured in the distal part of the nerve. The length of the cubital tunnel retinaculum increased by an average of 45% from full elbow extension to full flexion.

Aged↗

PubMed1994

Osteosynthesis of the proximal femur anchorage of a cervical nail.

One of the factors determining the stability of osteosynthesis is the mechanical strength of the bone fragments required for the anchorage of the implant. The aim is to study the driving of a Thornton nail in the proximal epiphysis of a human femur as a way to measure the strength of the trabecular bone and to predict the stability of the implanted system.

Aged↗

PubMed1994

BOP: biocompatible osteoconductive polymer: an experimental approach.

BOP (biocompatible osteoconductive polymer) is a material proposed for osteosyntheses and for filling of bone defects in orthopaedics, neurosurgery and stomatology. It is a composite made of a copolymer of N-vinylpyrrolidone and methylmethacrylate, of polyamide-6 fibers and of calcium gluconate. The histological investigation includes the study of 30 intact rabbit femurs instrumented with a BOP rod, as well as the study of organs of the reticuloendothelial system. The currently available results show the absence of toxicity on hematopoietic tissue. Zones of osteoblastic activity surround the rods, coupled with an osteoclastic reaction which may result in the partial fragmentation of the polyamide fibers and its incorporation in the newly formed bone. We also observed the encapsulation of the material. The biomechanical approach investigated the mechanical properties of the material in bending and in shear. The radiological aspects of the investigation consisted of computerized axial tomography of the implanted femurs to measure density at the bone-implant interface.

Animals↗

PubMed1994

[Surgical treatment of chronic hematogenous osteomyelitis. A series of 42 cases].

INTRODUCTION: Chronic hematogenous osteomyelitis (C.H.O.) is still a scourge of the non-industrialized countries. The authors operated on 420 cases of C.H.O. in Algeria between 1968 and 1987. A computerized analysis of the results of the surgical treatment of these 420 cases was made in Brussels, Belgium, by two of the authors. The results of this computerized study are exposed. MATERIAL AND METHODS: 67.1 per cent of the patients were male and 37.9 female. 68 per cent were operated before 16 y. of age. 381 lesions involved tubular bones: femur, tibia and humerus were the most frequent locations. Only 4 per cent of the cases had never presented a suppuration. Cultures of Staphylococcus were positive in 82 per cent of the cases. Surgical procedure was classical--bone window opening, sequestrectomy and saucerisation--in 359 cases. Operation was limited to soft tissues in 22 cases and bone resection was performed in 39 cases. Post-operative antibiotherapy was administered for a period of 10 to 60 days according to the patients. RESULTS: After the first operation with the classical procedure, results were satisfactory in 72 per cent of the cases but "healing" was achieved in 95 per cent of the cases after 2, 3, 4 and up to 6 operations. After bone resection, the rate of permanent healing was of 100 per cent. Follow-up was of more of 1 year (up to 22 y.) in 80 per cent of the cases. DISCUSSION: As far as classical procedure is concerned, a computerized analysis made according to 34 variables, led to the conclusions that the following variables could have a positive influence upon the prognosis: surgical team's experience, young age of the patient at the time of operation, subacute onset of the disease, location on the humerus, diaphysis of long bones, membranous and short bones, small number of sinuses, sclero-geodic radiologic appearance of the lesions, thin perifocal radiologic condensation, periosteal reaction, post-operative administration of two antibiotics. Excellent results of bone resection are pointed out but attention is drawn on the dangers of extending the indications for resection to the tubular bones. CONCLUSION: The authors conclude that improvement in the results of the surgical treatment of C.H.O. may only take place after improvement of the quality and duration of chemotherapy: that is confirmed by the results of a clinical trial they organized on the role of post-operative administration of Amoxicilline + Clavulanic Acid for a period of 60 days after surgery: 44 patients, 2 lost to follow-up, 4 failures and 38 "healings" (90.5 per cent) at 2 years and more.

Adolescent↗