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Biomedical subjects

J L Leroux

Publications and source records attributed to J L Leroux.

At least 37 records · Page 2Linked to original sources
PubMed1993

Sacral insufficiency fractures presenting as acute low-back pain. Biomechanical aspects.

Sacral insufficiency fractures are an often unsuspected cause of low-back pain in elderly women with osteopenia who have sustained unknown or only minimal trauma. The authors describe 10 cases of spontaneous sacral insufficiency fractures, confirmed by computed tomography, characterized by the onset of acute low-back pain. Differential clinical and radiographic diagnosis of these fractures is often difficult. Recognition of the characteristic scintigraphic patterns in sacral fractures, which are frequent in osteopenic patients, could avoid mistaken diagnoses and unnecessary tests or treatment. One of the striking feature of these sacral fractures is their invariable location. The fractures extend vertically in the sacral alae, parallel to the sacroiliac joints. They are located just lateral to the margins of the lumbar spine. This distribution suggests that such fractures could be partially caused by weight-bearing transmitted through the spine.

Aged↗
PubMed1993

Measurement of the bone mineral density of the os calcis as an indication of vertebral fracture in women with lumbar osteoarthritis.

In women with lumbar osteoarthritis, measurement of the os calcis bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA) as an indication of vertebral fracture was evaluated. The in vivo precision of the method was 1.28%. Age- and sex-matched control curves were evaluated using a control of 193 females. The correlation between spine BMD and os calcis BMD was significant (r = 0.65, p << 0.001). For the osteoporotic women without osteoarthritis (n = 34), there was no significant difference in the spine and the os calcis Z-scores (-1.99SD and -1.83SD respectively). Whereas for osteoporotic women with osteoarthritis (n = 30) the spine Z-score was -0.49SD the os calcis Z-score was -1.92SD. The difference was significant (p < 0.001). Receiver operating characteristic (ROC) curves demonstrate the superiority of the os calcis as a measurement site over the lumbar spine, in correlation with existing crush fractures in the presence of osteoarthritis. It is concluded that when lumbar osteoarthritis occurs measurement of the os calcis BMD using DEXA is clinically useful for the estimation of bone mass.

Absorptiometry, Photon↗
PubMed1993

[Determination of the instantaneous center of rotation of the shoulder using the ELITE system. Application to the study of normal and pathological abduction].

The authors determined the in vivo displacement of the instantaneous center of rotation (ICR) of the shoulder from data supplied by an optoelectronic system (ELITE System) which uses a specifically designed software program to achieve 3-dimensional analysis of abduction. The study involved 10 control subjects and 20 patients suffering from a periarticular disorder of the shoulder capsule retraction in 10 cases and rotator cuff tears before and after rehabilitation in 10 cases. This method provides an objective assessment of humeral head misalignment in relation to the glenoid cavity induced by the periarticular shoulder disorder and of the realignment achieved through rehabilitation. The proposed ICR calculation technique is entirely harmless for the patient in (particular because it requires no radiation analysis).

Adult↗
PubMed1992

Rotation-abduction analysis in 10 normal and 20 pathologic shoulders. Elite system application.

Kinematics of shoulder rotation-abduction in the plane of the scapula were analysed using the Elite system. We evaluated 10 asymptomatic subjects and 20 patients with painful conditions affecting the shoulder, 10 adhesive capsulitis and 10 rotator cuff-tears. The last pathologic cases were reexamined after rehabilitation treatment. The Elite system computed on line the trajectories of 8 retro reflective markers glued on the main reference points (3 on the spine, 3 on the scapula and 2 on the humerus). Angles and linear velocities were also evaluated. The lower humeral site displacement and gleno-humeral angle increase allowed differentiation of the normal shoulder rotation-abduction from the abnormal movement. Hence, rehabilitation progress could be followed up.

Adult↗
PubMed1992

Stenosis of the lumbar spinal canal in vertebral ankylosing hyperostosis.

Certain morphologic features frequently observed in radiography or computed tomography (CT) scan in patients with hyperostosis led us to study the association between a narrowed spinal canal and vertebral hyperostosis. Twenty-eight items were selected and studied by three different investigators (two rheumatologists and one radiologist) in radiographs and CT scans of 100 patients with acquired stenosis of the lumbar canal, with or without hyperostosis (46 and 54 cases, respectively). The most distinctive points that we suggest can be used as diagnostic criteria of the hyperostotic narrowed lumbar canal are anterior or posterior lateral marginal somatic osseous proliferations, proliferations of the nonarticular aspects of the posterior apophyses, and ossifications of the posterior articular capsule and of the ligaments (yellow ligament, posterior longitudinal ligament, and the supraspinal ligament). Four of these six criteria should be present to establish the diagnosis of hyperostotic lumbar stenosis. The appearance of lumbar hyperostosis on X-ray or CT scans differs from that of simple degenerative changes due to arthrosis, and the hyperostosis can be held responsible for dural compression.

Aged↗
PubMed1992

Lumbar posterior marginal node (LPMN) in adults. Report of fifteen cases.

This report concerns 15 adults (nine men and six women) who experienced lumbar and sciatic pain associated with an unusual defect of the edges of the vertebral bodies together with a small bony ridge protruding into the spinal canal. This lesion was well demonstrated by computed tomography and easily differentiated from the posterior longitudinal ligament or herniated disc calcifications, as well as from posterior degenerative ridge osteophytes. This lesion looked like the so-called lumbar posterior marginal node. First described in adolescents, this entity was considered as a traumatic fracture of the posterior ring apophysis. Recently, identical cases were noted in young adults in the absence of previous trauma, which were a particular type of marginal cartilaginous node. In the cases reported here, the computed tomographic scans suggested several mechanisms of formation of the vertebral lesion: a variant of marginal cartilaginous nodes; traumatic avulsion; avulsion related to disc herniation; and fusion of the avulsed bony fragment with the vertebral body.

Adult↗
PubMed1992

Effects of a single dose of methotrexate on 5- and 12-lipoxygenase products in patients with rheumatoid arthritis.

The inhibition of 5-lipoxygenase could be involved in the mechanism of action of methotrexate (MTX). We studied 8 patients with active rheumatoid arthritis (RA) immediately before and the day after the first dose of MTX (10 mg intramuscularly). Leukotriene B4 (LTB4) formation by polymorphonuclear leukocytes was significantly decreased (32%, p less than 0.01). This essentially involved released LTB4. A slight decrease was also obtained in omega-oxidation products. Similar results were obtained for plasma LTB4 (30%, p less than 0.02). A non-significant decrease in 5-HETE was noted. Conversely, 12-HETE was not modified. Our results suggest MTX has an effect on the 5-lipoxygenase pathway, particularly at the LTA4 epoxide hydrolase step, since 5-HETE and 6-trans-LTB4 isomers are not involved.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1992

[Effects of methotrexate on leukotriene and derivated lipoxygenase synthesis in polynuclear neutrophils in rheumatoid polyarthritis].

Methotrexate (MTX) has been proved to be effective in rheumatoid arthritis (RA). The mechanism of action of MTX in this disease remains unelucidated but may involve inhibition of the enzyme 5-lipoxygenase. Arachidonic acid metabolites were studied in eight patients with active RA immediately prior to and 24 hours after the first intramuscular injection of 10 mg MTX. None of the patients were taking corticosteroids. Nonsteroidal antiinflammatory drugs were withdrawn four days before the study. Reverse phase high-performance liquid chromatography was used to quantitate metabolites produced by 5-lipoxygenase (5-LO) and 12-LO in plasma (full spectrum of blood cells) and purified neutrophils (PN) after stimulation with calcium ionophore A 21387 (50 microM for 30 minutes and 5 microM for 5 minutes, respectively). LTB4 production by PNs was significantly decreased (-32%, p < 0.01) 24 hours after MTX administration. A moderate (-17%), nonsignificant (NS) fall in LTB4 omega-oxidation products (wP) was seen. Production of 5-HETE was also slightly decreased (-15%, NS). Findings in plasma were comparable, with a significant decrease in total LTB4 (-29.8%, p < 0.01) and moderate falls in wP (-18.8%, NS) and in 5-HETE production (-17%, NS). Production of 12-HETE was unchanged. These findings suggest that MTX in a single dose is responsible for a decrease in the synthesis of LTB4 and 5-LO products in neutrophils and other blood cells in RA patients but does not affect 12-LO activity.

Arthritis, Rheumatoid↗
PubMed1991

[Association of lumbar canal stenosis and ankylosing vertebral hyperostosis. Results of a multicenter study].

The authors report data collected in a study of the association of narrow lumbar canal and vertebral hyperostosis. Five centres (Montpellier, Toulouse, Lille, Lyons and Paris) participated in this cooperative study which was both retrospective and prospective. Grid case forms were sent to homogenise the date provided. Two hundred and sixty nine cases of symptomatic lumbar canal stenosis were collected; 89 (33 per cent) had hyperostosis. Hyperostosis was definite in 74 cases and probable in 15 other cases. Certain radiological and/or CT scan morphological factors seen frequently in the hyperostosis patients group led us to undertake a second study in 2 of the 5 centres (Montpellier and Toulouse) in order to identify their specificity. Twenty eight items were adopted and studied by 3 different evaluators (2 rheumatologists and one radiologist) in the X-ray films and CT scan documents of 100 patients with acquired lumbar canal stenosis with or without hyperostosis (46 and 54 cases respectively). The most discriminative appearances, which we suggest as diagnostic criteria of narrow lumbar canal with hyperostosis concern anterior and/or posterolateral marginal somatic bone proliferations on the non-articular surfaces of the posterior apophyses and ossifications of the posterior joint capsule and of the ligaments (ligamentum flavum--posterior longitudinal ligament--supraspinous ligament). Four of these 6 criteria are necessary to make the diagnosis of lumbar stenosis with hyperostosis. The radiological and CT scan appearances of lumbar hyperostosis appear to differ from ordinary degenerative changes of osteoarthrosis and hyperostosis may be held responsible for compression of the dural cul-de-sac.

Humans↗
PubMed1989

Osteomesopyknosis. Report of two new cases.

Two inherited cases of osteomesopyknosis are reported. This is an autosomal dominant osteosclerosis described by Maroteaux in 1980; its radiological abnormalities consist of increased density of the vertebral plates, pelvis, and sometimes of the upper part of the femur. Osteomesopyknosis, usually discovered incidentally on radiographic examination, is a mild form of familial osteosclerosis and must be distinguished from osteopetrosis which carries a worse prognosis.

Adolescent↗