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L Sedel

Publications and source records attributed to L Sedel.

At least 73 records · Page 4Linked to original sources
PubMed1997

Ceramic-ceramic and metal-polyethylene total hip replacements: comparison of pseudomembranes after loosening.

We made a semiquantitative study of the comparative histology of pseudomembranes from 12 loose cemented ceramic-ceramic and 18 metal-polyethylene total hip replacements. We found no significant difference in cellular reaction between the two groups, but there was a major difference in the origin of the particulate debris. In the metal-polyethylene group, polyethylene of articular origin was predominant, while in the ceramic-ceramic group the cellular reaction appeared to be a response to zirconia ceramic particles used to opacify cement used for fixation. Isolation and characterisation of the debris showed that the zirconia particles formed the greatest proportion (76%) in ceramic-ceramic hips, while alumina debris of articular origin formed only 12%. Our study has indicated that aseptic loosening of ceramic cups is not due to a response to debris generated at the articular interface, but to mechanical factors which lead to fragmentation of the cement.

Bone Cements↗
PubMed1996

Characterization of in vivo wear debris from ceramic-ceramic total hip arthroplasties.

In contrast to the much-studied mechanism of aseptic loosening of the metal-polyethylene joint couple, the mechanism responsible for failure of ceramic-ceramic (CC) total hip arthroplasties (THAs) has not been evaluated. The aim of this study was to conduct a systematic characterization of the in vivo wear debris from 15 cases of CC THAs revised for aseptic loosening. Two methods were used to evaluate the wear debris; a semiquantitative histological analysis of H&E-stained periprosthetic pseudomembranes; and an evaluation of isolated debris particles using SEM, energy-dispersive X-ray analysis, and image analysis. The three main types of particulate debris identified were titanium alloy (TiAlV) and alumina ceramic (Al2O3) of prosthetic origin, and zirconium dioxide (ZrO2) from the contrast agent used in the cement for prosthetic fixation. Alumina debris was present in the smallest proportion (12%) and was consistent with the low wear rate of the CC joint couple. Zirconium dioxide debris was present in the greatest proportion (76%) and was an unexpected finding. The ZrO2 debris represented microstructural grains of the original ZrO2 particles added as contrast agent to the cement. The presence of a histiocytic foreign body reaction to ZrO2 debris on histologic sections leads us to believe that these particles play an important role in aseptic loosening of the CC THAs evaluated in this study.

Alloys↗
PubMed1996

Avascular necrosis of the femoral head after allogenic bone-marrow transplantation. A retrospective study of 27 consecutive THAs with a minimal two-year follow-up.

After an allogenic bone-marrow transplant, avascular necrosis of the femoral head may affect young adults, producing destructive lesions which require hip replacement. We have reviewed 27 consecutive such total hip arthroplasties (THA) at a minimal follow-up of two years. Of these, 20 were primary operations for Ficat (1985) stage-III and stage-IV lesions, and seven were revisions after the failure of previous surgery. The median age at operation was 30 years (17.5 to 44). The prostheses had a cemented, collared titanium-alloy stem, an alumina-alumina joint, and a press-fit socket. Seven had a titanium-alloy metal back and 20 had all-alumina cups of which six had to be cemented. At an average follow-up of five years, no patient had been lost to follow-up. One had died from septicaemia after two years and another with chronic graft-versus-host disease developed a deep infection 2.5 years postoperatively and had a successful revision. There were no revisions for aseptic loosening. The clinical results on the Merle d'Aubigné++ and Postel (1954) scale were very good or excellent in 23 hips (88%), good in one and fair in two. Ten hips showed incomplete acetabular radiolucencies less than 1 mm thick, but there were no radiolucent lines around the stems. We conclude that for these difficult patients THA with ceramic joints and careful technique provides the best short- and medium-term option after the failure of medical treatment.

Adolescent↗
PubMed1995

Bone resorption at the femoral neck is dependent on local factors in nonosteoporotic late postmenopausal women: an in vitro-in vivo study.

Local mediators of bone resorption may be involved in bone loss in recently postmenopausal women and in osteoporosis. In the present study, we investigated the production of cytokines and the formation of osteoclast-like cells in marrow cultures from 16 late postmenopausal nonosteoporotic women (mean age: 66 +/- 8 years; time after menopause: 15 +/- 8 years) undergoing hip replacement for arthrosis. Marrow adherent mononuclear cells (MMNC) isolated from femoral diaphysis marrow were cultured for 10 days in the absence or in the presence of 1,25(OH)2D3. In vivo bone resorption was concomitantly assessed by histomorphometry on femoral neck bone sections. The number of TRAP+ multinucleated cells obtained after 10 days in MMNC cultured in the presence of 1,25(OH)2D3 correlated with the number of osteoclasts measured on the bone femoral neck biopsies (r = 0.65, p < 0.01), suggesting that the formation of multinucleated cells in vitro could reflect the osteoclast differentiation in vivo. Furthermore, the number of osteoclasts was related to the eroded volume and the trabecular separation of the femoral neck bone biopsies. Finally, the release of interleukin-1 (IL-1), IL-6, and TNF-alpha by cultures of peripheral blood mononuclear cells (PBMC) and MMNC was measured by radioimmunoassay. The cytokine levels of basal and 1,25(OH)2D3-treated MMNC decreased from days 2 to 5 and then reached a plateau to day 10. The number of TRAP+ multinucleated cells obtained after 10 days in MMNC cultures correlated with the basal IL-6 release in the same cultures determined at day 2 (r = 0.55, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

[Orthopedic biomaterials].

It is very challenging to insure long term security and effectiveness for joint arthroplasties, artificial ligaments, extensive bone replacement and some other orthopaedic biomaterials. How can we predict the long term security and efficacy of such an implant? Only an interdisciplinary approach can provide a satisfactory answer. The surgeon must define the needs, he must find the appropriate surgical techniques and conduct the clinical trial. The material scientist must elaborate safe and secure materials with regards to their biotolerance and mechanical resistance. This has to be performed in close connection with the biomechanics lab. Biomechanic Science must predict the expected stresses. It has to design special simulator to quantify in vitro material toughness, wear characteristics, lubrication, behaviour and surface deformation. Biological and mechanical standardized tests have to be carried on. Then it is possible to conduct a clinical trial, prospectively in comparison to another already developed material. Clinical studies could serve to measure efficacy and radiological modification. After failure, it is possible to analyse retrieved specimen, to measure the material degradation in real environment, to perform biological studies on retrieved tissues i.e. : macrophagic activities, tissue response, bone ingrowth, inflammatory or immunological reaction. For more than twenty years we worked on alumina against alumina total hips. The idea was to develop a low debris system to enhance long term longevity of the prosthesis. The Charnley design has proven its effectiveness for more than fifteen years, but polyethylene wear is responsible for late failures. This is specially crucial for young patients, male sex and high activity level patients. At the beginning, biological studies and mechanical tests were performed, it appeared that the biological tolerance of alumina ceramic was excellent, the fracture toughness was adequate, but there were some problems related to alumina fixation in the body and also alumina head fixation on metallic stem. Alumina material improved with time. It was possible to diminish the fracture risks and to increase the safety. Parallel information from the first period was used to increase the material quality, the surgical techniques and also to define indication in the use of such material. It is now clear and it also has been published that alumina against alumina system has proved to be as safe as Charnley total hips. It has been proved to give better results in the young age population. Then it is now possible to operate on very young patients, to allow these patients to perform heavy work, sports and regular daily activity for their demand.(ABSTRACT TRUNCATED AT 400 WORDS)

Biocompatible Materials↗
PubMed1994

[Total hip prosthesis in young patients].

Total hip prostheses are functional for a shorter period of time in young patients than in elderly. This problem is essentially related to the production of wear debris consecutively to metal versus polyethylene friction. New materials, such as alumina, produce less debris and therefore have been used for more than fifteen years with acceptable results at ten years (> 90% of functional hips). Total hip prostheses are sometimes needed in young patients suffering of post traumatic lesions, severe osteonecrosis and early osteoarthritis. In these cases, the indication of the prostheses should be accurately discussed, since it gives very often excellent results in comparison to more conservative treatments.

Adult↗
PubMed1994

Avascular necrosis of bone after allogeneic bone marrow transplantation: clinical findings, incidence and risk factors.

In the present study we describe the incidence, clinical course, and management of avascular necrosis of bone following allogeneic bone marrow transplantation, and identify risk factors related to its development. All patients developing avascular necrosis of bone after allogeneic bone marrow transplantation between January 1974 and September 1992 were included in the analysis and were studied using the Hôpital Saint Louis Bone Marrow Transplant Database and hospital records. 27/727 allogeneic transplant recipients developed avascular necrosis leading to an 8.1% incidence at 5 years, by product limit estimate, ranging from 5% to 11.2%. Symptoms developed 119-1747 d (median 398 d) after transplantation. In these 27 patients a total of 52 joints were affected (mean 1.92 per patient, range 1-7). The hip joint was most often affected (69% of patients). All patients had joint pain that led to diagnosis by means of standard radiographs with or without the help of technetium-99 scans and/or magnetic resonance imaging. All but three patients received steroid therapy for acute graft-versus-host disease. Among 10 factors tested, three were shown to be significantly linked to an increased risk for developing avascular necrosis by multivariate analysis: male gender (relative risk (RR) 4.72, P = 0.002), age older than 16 (RR = 3.87, P = 0.004), and acute graft-versus-host disease requiring steroid therapy (RR = 6.30, P = 0.0002). 10 patients (37%) required joint replacement within 19 months (range 2-42) following diagnosis of avascular necrosis. In conclusion, avascular necrosis of bone is a frequent late complication of allogeneic bone marrow transplantation causing significant morbidity and requiring replacement surgery in one-third of affected patients. In this 18-year single-centre survey, older age, male gender and steroid therapy given for acute graft-versus-host disease were shown to independently increase the risk of avascular necrosis of bone.

Acute Disease↗
PubMed1994

Alumina-alumina hip replacement in patients younger than 50 years old.

From April 1977 to December 1990, 131 total hip arthroplasties were performed on 113 patients younger than 50 years of age (median, 41 years); 64 were men and 49 women. The majority were active people. Sixty-six hips had no previous operations, and 33 had at least one previous arthroplasty. The femoral component was a cemented collared titanium alloy stem, and alumina socket was cemented for 99 hips and press-fit for 32. The mean follow-up period was five years, with 32 hips followed for more than ten years. Revision arthroplasty was considered as a failure. Survivorship analysis depicted a 97.5% rate of survival at five years, an 89.4% rate at ten years, and an 86.2% at 11 years. Nine revisions were performed: one experienced a femoral head rupture after three years, one had bipolar loosening, one experienced femoral cystic formation, and six were revised for acetabular cup loosening, all from the cemented group. Two revisions occurred on the same patient. No stem revision was necessary before ten years. Only one of these revisions was required in patients aged 40 or younger (64 patients). Alumina-alumina friction is an extremely interesting phenomenon in young patients, and could be related to the low wear debris production.

Adult↗
PubMed1993

Nerve grafting for traction injuries of the common peroneal nerve. A report of 17 cases.

We report 17 patients who had grafting of the common peroneal nerve after traction injuries. Sixteen were reviewed at a median follow-up of 36 months. The nerve gap ranged from 7 to 20 cm. A functionally satisfactory result was achieved in six patients (37.5%), a fair result in six and a poor result in four. Seven patients had, in addition, a posterior tibialis tendon transfer; this improved the result in five. Grafting produced some satisfactory results even when the nerve gap was as long as 20 cm.

Adolescent↗
PubMed1992

Prostaglandin E2 level in tissue surrounding aseptic failed total hips. Effects of materials.

Production of inflammatory mediators (IM) by cells and specifically macrophages around loosened implants may be responsible for their loosening. Our hypothesis was that different materials give rise to different amounts of these IM. It is thought that alumina/alumina for total hip replacement (THR), which has been used for 15 years in our orthopedic department, may produce less IM than other systems. We initiated a clinical prospective study to measure the level of prostaglandin E2 (PGE2) in tissue surrounding loosened prostheses to quantify PGE2 production regarding the types of material involved in the friction couple, i.e., alumina/alumina versus metal/polyethylene, and the type of fixation, i.e., cemented versus cementless. A total of 29 THR revisions were performed in 28 patients. Four implant groups were identified: alumina/alumina cemented, alumina/alumina cementless, metal/polyethylene cemented, and metal/polyethylene cementless. For each revision, tissues surrounding the failed implants were harvested and processed, and the PGE2 was measured in a blind manner using an immunoassay technique. As the measuring technique was difficult, at least three determinations for each sample were necessary. Some samples were excluded from the analysis for various reasons, for example, second or further revisions involving many different materials in the past, conjunction of metallic and alumina debris and samples taken from non-loosened components. Finally, 15 samples were considered adequate for inclusion in this study. Two groups were analyzed and compared: the alumina/alumina couple and the metal/polyethylene couple. Tissue surrounding the first group demonstrated a PGE2 level of 69 +/- 56 fmol/mg wet weight compared to 202 +/- 156 fmol/mg for the second.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetabulum↗
PubMed1992

Ceramic hips.

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Adult↗
PubMed1992

Ten-year survivorship of cemented ceramic-ceramic total hip prosthesis.

In the first 187 consecutive alumina-alumina combination hip arthroplasties performed from 1977 to 1979, both components were cemented with conventional techniques. At ten-year follow-up evaluation, 87 patients were reviewed or interviewed by telephone, 37 were dead, 39 were lost to follow-up evaluation, and 24 failures were reoperated on before the end of ten years. The major cause of failure was aseptic loosening of the acetabular component (15 failures). Fracture of the socket and of the femoral head occurred in five patients in this series. However, these complications were not seen with components manufactured after 1979. At the end of ten years, survivorship analysis depicted a 82.59% survival rate when reoperation was considered as failure and a 88.57% rate when reoperation for aseptic loosening was considered as failure. The femoral component had a 99.16% survival rate and the acetabular component had an 88.57% survival rate when reoperation for aseptic loosening was considered as failure. Age, appearance of a two- or three-zone demarcation at the intermediate follow-up evaluation, and outer diameter of the acetabular component were the major parameters influencing the results. Better results observed in the population younger than 50 years of age may be related to the small amount of wear debris produced by the alumina-alumina combination. This combination in hip prosthesis is secure, but should be implanted in young and active patients; the outer diameter of the acetabular component must be at least 50 mm. The major problem that remains is the socket's fixation. It could be improved by a design modification, by choosing another mode of fixation, or both.

Aluminum Oxide↗
PubMed1991

[Arthrodesis of the shoulder in paralysis of the brachial plexus. Apropos of 2 cases].

Twenty-three shoulder arthrodeses after brachial plexus injuries have been performed. Average time between injury and arthrodesis was 3.4 years. 18 patients had palliative procedures or direct approach of the brachial plexus to improve shoulder and hand function. Average follow-up was 5 years and 11 months. An analysis based on pain, function, and fusion occurrence gave 15 good, 2 fair and 4 poor results. The authors conclude that the shoulder arthrodesis is indicated when elbow and hand functions are sufficient and deafferentation pain has not occurred.

Adult↗