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Biomedical subjects

D Mainard

Publications and source records attributed to D Mainard.

At least 19 recordsLinked to original sources
PubMed2000

The structure of the cartilaginous end-plates in elder people.

Low back pain is the leading cause of work-related disability. Degeneration of the intervertebral disc (IVD), the boundaries of which with age-related changes remain obscure, is considered to be its most important cause. The cartilaginous end-plate (CEP) is the anatomic boundary of the IVD. Since the latter is avascular in adults, the CEP is supposed to play a key role in the metabolism of the IVD. Consequently, it has been postulated that the decrease in permeability of the CEP is the main cause of degeneration of the disc. However, the permeability depends at least partially on the morphologic state of the CEP. Little is known about the age-related changes of the CEP compared to those of the IVD. The objectives of the study were to examine the CEP at different ages, to classify the age-related changes in both the CEP and IVD, and to compare them. The intervertebral discs of the five levels of ten human lumbar spines were collected from cadavers aged from 47 to 78 years, and studied macroscopically and microscopically. Morphologic features of the CEP (thickness, IVD/CEP length ratio, degree of calcification, marrow contacts, CEP-VB and CEP-IVD separations) were measured. Morphologic grades were assigned for both the CEP and the IVD. No significant differences were found with regard to these features in the different age-groups. On the other hand, no significant correlation was found between the morphologic grade of the CEP and that of the IVD, suggesting that the importance of the CEP in disc degeneration may be debatable.

Aged↗
PubMed2000

Influence of trauma induced by judo practice on postural control.

Although high-level sports develop specific physiological and sensorimotor abilities involved in balance control, they also increase the risk of injuries. The influence on postural control of lower limb trauma induced by judo practice was examined in healthy and previously injured judoists (PIJ). During static and dynamic tests, performed with or without vision, PIJ achieved the best performances in maintaining proper balance, except for those with the most severe antecedents of trauma. The severity of the pathology appeared to be the most important parameter prejudicial to balance control while the location, frequency and diversity of trauma had only a modest impact. This shows that PIJ develop excellent sensory and cognitive adaptation abilities to constraints involving new patterns of compensation and of body scheme.

Adaptation, Physiological↗
PubMed2000

The role of 3D-microscopy in the study of chondrocyte-matrix interaction (alginate bead or sponge, rat femoral head cap, human osteoarthritic cartilage) and pharmacological application.

The potentialities of a new non-invasive optical scanning microscopy technique were evaluated through 3D analysis of chondrocyte-matrix interactions. Five different 2D or 3D culture systems were used: (1) MonoLayer (ML) of human chondrosarcoma cell line; (2) rat or human chondrocytes encapsulated in Alginate Bead (AB); (3) human chondrocytes encapsulated in Alginate Sponge (AS); (4) Rat Femoral Head Cap (RFHC); (5) slices of knee human Osteoarthritic Cartilage (HOAC). Chondrocytes ML, AB, RFHC were incubated for 24 h in vitro in the presence of recombinant human interleukin1-beta (rhIL1-beta) and the effects on cytoskeleton organisation (F-actin filament), Focal Adhesion Kinase (FAK) expression (tyrosine kinase), collagenase B expression (metalloprotease) were studied. Furthermore, the production of intracellular IL1-beta by LPS- or rhIL1-beta-stimulated chondrocytes was shown to be partly suppressed by rhein (active metabolite of diacerhein) in all culture systems. This high resolution light microscopy gave complementary information that could be important for a better understanding of the interaction of chondrocytes with the extracellular matrix in a variety of culture devices.

Actins↗
PubMed2000

[Quality of life assessment one year after total hip or knee arthroplasty].

PURPOSE OF THE STUDY: The development of quality of life (QOL) instruments has made it possible to obtain an objective assessment of the impact of surgical procedures taking into consideration the physical, psychological and social aspects of the patient's everyday activities. The aim of this work was to evaluate the short-term and long-term course of QOL after total hip arthroplasty (THA) and total knee arthroplasty (TKA). MATERIALS AND METHODS: This study included a prospective multicentric cohort of patients with a first intention indication for degenerative bone and joint disease. Clinical assessment was obtained preoperatively and 6 weeks, 6 months and 12 months postoperatively. The Merle d'Aubigné and Harris scores were determined for THA and the Hospital Special Surgery score for TKA. Clinical data (pain, walking distance), and QOL scores [French version of the Nottingham Health Profile (NHP) and the French version of the Arthritis Impact Measurement Scale 2 (AIMS2)] were also obtained. RESULTS: One hundred twenty-three patients had a THA (mean age 62 years) and 60 had a TKA (mean age 68 years). Preoperative clinical features were those commonly found in these populations. For THA, the 6-week, 6-month and 1-year assessments showed an improvement (2.7 and 2.8 points on the 0 to 10 NHP). For TKA, improvement came later and was less significant with 0.8, 1.8 and 1.5 point improvements. The AIMS 2 did not appear to be perfectly adapted to measure this dimension. Improvement in pain came earlier and was greater for THA than for TKA on all measurement scales. For THA, psychological capacity improved by 0.7, 1.4 and 1.5 points on the 0 to 10 AIMS 2 at 6 weeks, 6 months and 12 months respectively. For TKA, improvement was to the same order with 1.1 and 1.2 point improvements at 6 weeks and 6 months respectively. DISCUSSION: These findings confirm the clear improvement in QOL after THA and TKA, mainly due to physical and psychological dimensions. The QOL measurements allow comparisons with other surgical procedures in other fields. They provide supplementary information, notably concerning pain and are particularly useful in orthopedic surgery. The questionnaires are generally well accepted by the patients, particularly short self-administered questionnaires. They provide useful information on the efficacy of THA and TKA in terms of human and social costs and open new perspectives for analysis of prognostic factors for optimal QOL of operated patients.

Activities of Daily Living↗
PubMed1998

Separation and quantification by ion-association capillary zone electrophoresis of unsaturated disaccharide units of chondroitin sulfates and oligosaccharides derived from hyaluronan.

An analytical method has been developed for assay of unsaturated disaccharides of chondroitin sulfates and of oligosaccharides (tetra- and hexasaccharides) of hyaluronan, using ion-association capillary zone electrophoresis. Samples were applied at the anode (the usual polarity), using a borate buffer modified by an ion-pairing reagent, tetrabutylammonium (TBA) phosphate, and the effect of the concentration of the ion-pairing reagent on various electrophoretic parameters (electroosmotic flow, electrophoretic mobility of products, capacity factors) was observed. Increasing concentrations of the reagent led to a decrease of zeta potential, probably due to specific adsorption of the quaternary ammonium ion onto the capillary wall. The authors propose a mechanism of separation, in which anionic borate complexes are formed and interact with TBA ion inside the capillary tube. The capillary electrophoretic system described is potentially a powerful method for specific measurement of the concentrations in joint tissues of chondroitin 4-sulfate, chondroitin 6-sulfate, and hyaluronan, whose relative abundances may vary in various diseases or after local treatments with, for example, antiinflammatory drugs, chondroprotective agents, or orthopedic implants.

Chondroitin Sulfates↗
PubMed1998

Amyloid and non-amyloid carpal tunnel syndrome in patients receiving chronic renal dialysis.

OBJECTIVE: To determine the prevalence of amyloid deposits among patients with carpal tunnel syndrome (CTS) receiving dialysis, and to investigate the factors associated with amyloid and non-amyloid CTS. METHODS: Subjects for this prospective study were dialysis patients who underwent surgery for CTS in the same surgical unit between 1989 and 1997. CTS was diagnosed from clinical and electromyographic (EMG) findings. Systematic standard radiographs and laboratory data were also obtained. Surgical investigations included systematic macroscopic examination and biopsy of the epineurium, flexor retinaculum, synovium, and flexor tendon sheaths. Samples were stained for amyloid and examined by plain and polarized light microscopy, immunohistochemistry, and electron microscopy. RESULTS: Forty-one samples from 30 patients (11 bilateral cases) were examined. Amyloid deposits were found in 26 samples from 18 patients (7 M, 11 F). Fifteen samples from 12 patients (3 M, 9 F) showed no amyloid deposits. Amyloid CTS was statistically significantly associated with arthralgia and longterm dialysis [mean 13.3 (range 5.5-23) vs 7.5 yrs (range 3 mo-14 yrs)] in non-amyloid CTS. Flexor tenosynovitis and carpal bone erosion occurred more frequently in amyloid CTS. There were no statistically significant differences between the 2 groups in clinical, laboratory or EMG findings, type of dialysis membrane, or frequency of ipsilateral fistula. Only amyloid CTS was recurrent. CONCLUSION: Amyloid deposits were confirmed microscopically in 63.4% of patients. The relatively large number of cases of non-amyloid CTS without signs of dialysis associated arthropathy suggests that CTS is not a satisfactory criterion for diagnosis of dialysis arthropathy or beta2-microglobulin amyloidosis unless the presence of amyloid has been confirmed or duration of dialysis treatment has been at least 15 years.

Adult↗
PubMed1997

[Flatfoot].

The flat foot is a very frequent cause of consultation in podology. The lesion is rapidly fixed, and osteoarthrosis appears. The diagnosis is clinical. A podoscopic and radiographic examination is necessary to appreciate the evolutivity of the deformity. The treatment is almost conservative: the wearing of orthesis is often sufficient. The indications of the surgery are rare; sometimes it is possible to do plastic techniques (in particular on the posterior tibial tendon) but, when the foot is painful, the osteoarthrosis is present and it is necessary to do arthrodesis, in particular in the talonavicular joint.

Adolescent↗
PubMed1997

[Current treatment of static deformities of the great toe].

The modern techniques of treatment of the hallux valgus are founded on the biomechanic and permit to give again a good function of the big toe. The authors prefer the osseous methods and specially the phalangeal and metatarsal osteotomies. It is necessary also to do a lateral release of the metatarsophalangeal joint and an exostosectomy. The late results are good.

Adult↗
PubMed1996

Stereoselective distribution of tiaprofenic acid in synovium and cartilage in osteoarthritic patients.

OBJECTIVE: In order to document the stereoselective distribution in joints of a chiral nonsteroidal anti-inflammatory drug, the relative affinities of the enantiomers of tiaprofenic acid in synovium and for cartilage were compared. METHODS: The distribution of tiaprofenic acid in synovium and in cartilage was studied 25 h after administering the racemic drug for 2 days (600 mg of a sustained-release preparation, once daily), in 12 inpatients with osteoarthritis of the hip requiring arthroplasty. Enantiomers were quantified in plasma and freeze-ground tissues by a chiral HPLC assay. RESULTS: Plasma concentrations of the dextrorotatory (R) enantiomer (0.40 microgram/ml) were higher than those of its antipode. The concentration of racemate in synovium (in dried and fresh tissues, 150% and 40%, respectively, of the concentration in plasma) was much higher than that in cartilage (in dried tissues 32% of the plasma concentration). The ratio of the active, dextrorotatory (R) enantiomer to its antipode was higher in synovial tissue than in plasma. CONCLUSION: Tiaprofenic acid is distributed stereoselectively in plasma and synovium, which contain a higher concentration of the active, dextrorotatory (R) enantiomer. In cartilage, it reaches only a very low concentration.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1996

Evaluation of the effect of three surface treatments on the biocompatibility of 316L stainless steel using human differentiated cells.

AISI 316L stainless steel (SS) is widely used in orthopaedic implantology, although biological complications may result from its insufficient mechanical and tribological properties. In order to improve the wear and corrosion resistance as well as the hardness of 316L SS, three surface treatments, derived from those applied in mechanical engineering industries, were investigated: (1) glow discharge nitrogen implantation, (2) carbon-doped stainless steel coating sputtering and (3) low temperature plasma nitriding. Surface characterization according to the different heat treatments showed that corrosion and wear resistance were strongly improved, especially by ion implantation or carbon-doped SS coating sputtering. In the same way, microhardness was significantly increased after the three treatments. The effect of such treatments on the biocompatibility of 316L SS was studied with human osteoblast and fibroblast cultures. Basic and specific features of the cells showed that ion-implanted and carbon-doped stainless steels were biocompatible, whereas dramatic cellular reactions were noted when contacted with nitrided stainless steel. A hypothesis is given to explain this observation but further experiments are needed to optimize the nitriding process. Nitrogen implantation and carbon-doped layer deposition could be efficient means for improving the physical properties of stainless steel without affecting its biocompatibility. Such surface treatments may have relevance for increasing the life time of 316L biomedical devices.

Alkaline Phosphatase↗
PubMed1996

Cytocompatibility of Ti-6Al-4V and Ti-5Al-2.5Fe alloys according to three surface treatments, using human fibroblasts and osteoblasts.

Titanium alloys are well known for their superior mechanical properties as well as for their good biocompatibility, making them desirable as surgical implant materials. However, these alloys have been proven to behave poorly in friction since wear particles were often detected in tissues and organs associated with titanium implants. In this paper, three surface treatments were investigated in order to improve the wear resistance and the hardness of Ti-6Al-4V and Ti-5Al-2.5Fe: (a) glow discharge nitrogen implantation (10(17) atoms cm-2), (b) plasma nitriding by plasma diffusion treatment (PDT) and (c) deposition of TiN layer by plasma-assisted chemical vapour deposition (PACVD) additionally to PDT. Surface characterization after the different treatments showed considerable improvement in surface hardness, especially after the two nitriding processes. Moreover, the good corrosion resistance of untreated alloys was maintained. A cell culture model using human cells was chosen to study the effect of such treatments on the cytocompatibility of these materials. The results showed that Ti-5Al-2.5Fe alloy was as cytocompatible as the Ti-6Al-4V alloy and the same surface treatment led to identical biological consequences on both alloys. Nitrogen implantation did not modify at all the cellular behaviour observed on untreated samples. After the two nitriding treatments, cell proliferation and viability appeared to be significantly reduced and the scanning electron microscopy study revealed somewhat irregular surface states. However, osteoblast phenotype expression and protein synthesis capacity were not affected. PDT and PACVD may be interesting alternatives to the physical vapour deposition technique.

Alkaline Phosphatase↗
PubMed1996

[The Staca nail-plate in the treatment of trochanteric fractures].

PURPOSE OF THE STUDY: The Staca nail-plate (SNP) is 32 years old. This implant was created by Descamp and Kerner from Nice in 1964. This study evaluates the experience with the SNP in two Orthopaedic Departments from Metz and Nancy Regional Hospitals, between January 1989 and July 1991. MATERIAL AND METHODS: This is a clinical and radiological retrospective study. Out of the 175 patients, 152 were reviewed at 3 months and 127 at more than 9 months. The radiological assessment was made by measuring the post-operative cervical angle, the position of the nail within the femoral neck, the inter-fragmentary distance and the distance between nail and femoral head cartilage. 175 trochanteric fractures (119 women and 56 men) had osteosynthesis with the SNP. The mean age was 79 years (range: 36 to 96 years). Only 29 patients were free of general associated pathology. The fracture was always traumatic. The right femur was involved in 97 cases. Following the Ender classification there were 87 stable and 88 unstable fractures (59 complex pertrochanteric, 19 inter and sub-trochanteric and trochantero-diaphyseal). RESULTS: Post-operative reduction was anatomical in 66 per cent and satisfactory in 89 per cent of cases. In three cases there was an acetabular protrusion of the nail, in two cases there was a varus reduction and fixation and in six cases the plate was not fitting correctly the diaphysis. The average per-operative blood-loss was 300 cc. There was one per-operative death and eight early post-operative deaths. Sitting was allowed 24 hrs, after surgery in 94 per cent of patients. 68 per cent of patients started walking within the first 15 days after surgery. There were 37 per cent general complications, mainly respiratory and urinary infections, but also 2 deep-vein phlebitis, with pulmonary embolism and death. 17 post-operative hematoma were noted, out of which two required surgery. The general mortality reached 15 per cent in three months and 22 per cent in nine months. 70 per cent of the patients were free of pain at 3 months and 78 per cent at 9 months, 65 per cent being able to walk without crutches. Nail acetabular protrusion was observed in 16 cases (3 in early post-operative period, 8 within three months and 2 between the third and the ninth month). The protrusion was related to the nail positioning in 11 out of the 16 cases. This complication required SNP removal in 7 cases, replacement of the SNP in 3 cases and total hip arthroplasty in two cases. Correct nail length assessment is the important step in order to avoid protrusion and has to take into account the interfragmentary distance after reduction (if any). A good per-operative nail impaction is mandatory. CONCLUSION: Compared to other implants (THS, DHS, Gamma-nail, Ender), the SNP gives comparable results and a stable fixation. The SNP is a reliable implant. The most common complication in our series is protrusion which required reintervention in 6.8 per cent of the cases. Currently we avoid this complication by a good per-operative nail impaction.

Adult↗
PubMed1996

[Quality of life after orthopedic surgery of the lower limbs. A new approach].

Measuring quality of life is a new approach of interest to all health professionals involved in orthopedic surgery. This paper is an introduction to the multidimensional concept of health related quality of life. Various types of measurement instruments are described: first the psychometric questionnaires, distinguishing generic measures useful in various conditions and disease-specific measures for a given disease or condition, and the recently developed individual instrument; second, econometric measures based on the decision theory. The potential objectives for use and the required measurement properties of these instruments are described. The need and corresponding methods for a cross-cultural adaptation into French when using questionnaire originally developed in English are reported. A literature review focuses on studies reporting such measures used to evaluate orthopedic surgery, particularly in the way patients perceive the results of hip and knee arthroplasty. Further perspectives for clinical and epidemiological research are numerous. Several avenues for research and for use in clinical practice are proposed.

Decision Support Techniques↗
PubMed1995

Magnetic resonance imaging may be an asset to diagnose and classify fluoroquinolone-associated Achilles tendinitis.

The aim of this study was to document the accuracy of magnetic resonance imaging (MRI) during fluoroquinolone-associated Achilles tendinitis. Fourteen Achilles tendons were examined by MRI (T1 and T2 or T2*-weighted sequences) in nine patients with typical tendinopathy (13 cases of tendinitis and 1 rupture) during fluoroquinolone therapy. Tendinous involvement was classified according to the prominence of intra- or peritendinous changes. The most typical feature was the presence of intratendinous changes, longitudinal or transversal, detected on T1 or T2-weighted sequences. Peritendinitis was most visible in two cases and nodular involvement in three cases. It was concluded that MRI appears a helpful and accurate method in identifying and classifying such iatrogenic tendinitis. In addition, MRI indicates orthopedic management when detecting risk of rupture.

Achilles Tendon↗
PubMed1995

Antivitamin K prevents heterotopic ossification after hip arthroplasty in diffuse idiopathic skeletal hyperostosis. A retrospective study in 67 patients.

We investigated the risk of heterotopic ossification (HO) after total hip arthroplasty in 67 patients, 16 of whom had diffuse idiopathic skeletal hyperostosis (DISH). DISH was diagnosed on chest, dorsolumbar and pelvic radiographs. HO was graded according to DeLee et al. (1976). After a 1.4 year follow-up, 21 patients had HO. The risk of HO was 5 times higher in DISH than in non-DISH patients, but lower in patients receiving antivitamin K than in those receiving other anticoagulant therapy (relative risk 0.2). Our findings lead us to recommend that DISH should be diagnosed preoperatively for preventive therapy. They also suggest a preventive effect of antivitamin K against heterotopic ossification after hip arthroplasty.

Acenocoumarol↗