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R Louis

Publications and source records attributed to R Louis.

At least 109 records · Page 6Linked to original sources
PubMed1987

Anatomic factors in the femoral implantation of the Ilizarov external fixator.

Ilizarov's method of external fixation with compression or distraction for lesions of the limbs demonstrates new possibilities in osteogenesis. Its performance with double horizontal pinning on several external rings calls for precautions to avoid lesions of the vessels, nerves and joints. This study, based on anatomic sections radiographed after opacification of the arterial system, makes it possible to propose rules for insertion of the pins. Insertion of the anteromedial pins of the thigh should be made 2 cm in front of the line of projection of the femoral artery, between the middle of the inguinal ligament and the posterior margin of the medial condyle. Insertion of the posterolateral thigh pins should be made 2 cm lateral to the line of projection of the sciatic nerve, between the center of the ischiotrochanteric interval, the apex of the popliteal fossa and the posterior aspect of the head of the fibula.

Bone Nails↗
PubMed1987

[Ventral approach to the cervical spine].

Since they were introduced in 1950, ventral approaches for surgical operations on the cervical spine have become widely used. The most frequently used is the anteromedian approach, passing along the anterior border of the sternocleidomastoideus muscle and then between the upper gastrointestinal tract and the vascular bundle to give access to the spine. This approach allows access to practically every segment of the cervical spine. The significance of the transoral approach is stressed in the literature, and we ourselves are also convinced of its importance. In this paper, however, the combined anteroposterior procedures and the cervicothoracic methods used for the transitional zone are also described. Complications affecting the upper gastrointestinal tract, the vessels or the nerves are always possible, and to reduce their likelihood to a minimum it is essential to make a detailed study of the complicated anatomy of the neck region.

Cervical Vertebrae↗
PubMed1986

Fusion of the lumbar and sacral spine by internal fixation with screw plates.

From 1972 to 1982, 455 patients had arthrodesis and other operations with screw-plate internal fixation of the lumbosacral spine. Of these 455 patients, 440-413 of whom had had spinal fusion and 27 of whom had undergone pars interarticularis reconstruction--were evaluated for a mean follow-up period of 31.6 months. The principal indications for single-stage posterior fusion, which was performed in 266 cases, were severe degenerative joint disease and painful spondylolysis, while the primary indications for combined anterior and posterior repair, which was undertaken in 145 cases, were spondylolisthesis and malignant tumors. Two cases had single-stage anterior fusion. Initial anterior surgery was performed to achieve reduction of vertebral displacement, while the posterior approach was carried out to allow for fusion of the posterior joints and for osteosynthesis; specially-designed screw plates were attached to the pedicle for this purpose. The rate of solid fusion was 97.4% in the single-stage posterior procedures and 100% in patients who had been treated by a combined approach. Only five neurologic complications were encountered out of the combined approach (two regressive cauda equina syndromes and three regressive L5 nerve root pareses), and these occurred early in the investigation, when the technique was still being refined. Only six cases of single-stage posterior approach sustained a monoradicular lesion that subsided after the offending bone screw was removed. Such complications can be avoided if the surgeon is thoroughly familiar with the techniques described.

Adolescent↗
PubMed1985

Spinal stability as defined by the three-column spine concept.

The three-column spine concept is supported by anatomical data from dry European and African skeketons, by experiments on fresh cadaver spines without chemical fixation and by an extensive clinical and surgical experience. There exists an axial and a transverse stability. Axial stability is maintained along a vertical column system: this consists of two columns at the C1-C2 level and three columns from C2 to the sacrum. The anterior column is formed by the vertebral bodies and discs, and the two posterior columns by posterior joints. Transverse stability at the motion segment levels is produced by a coupling of bony buttresses and ligamentous brakes. The three-joint motion segment is characterized by a triangular disposition of joints with opposing joint spaces, thus supporting the articular orthogonal triangulation concept. These observations have a clinical relevance in the field of spinal growth, changes consequent upon wear in spinal joints and clinical instability.

Humans↗
PubMed1984

On-line monitoring of multiple precordial leads in high risk patients with coronary artery disease--a pilot study.

In a pilot study, a computerized precordial mapping system monitored ischaemia on-line in 50 patients (40 with acute myocardial infarction and 10 with unstable angina, class IV (Canadian Cardiovascular Society). All had ST-segment depression or elevation greater than or equal to 0.2 mV in one or more precordial leads when they were admitted to our coronary care unit. After preliminary precordial mapping with 48 electrodes to localize the area of ischemia, 5 to 8 electrodes were placed in and around the centre of the ST-segment changes. The patients were monitored between 24 and 48 h (mean 35.5 h). To minimize problems caused by artifacts, ECG signal quality was improved by the averaging technique. Thereafter, the ECG was evaluated with respect to Q and R wave amplitudes and ST-segment changes. At 3 min intervals, Q and R wave amplitudes and ST segment elevations or depressions, summed for all leads were plotted as a histogram. ECG signal quality was excellent and there were no problems with the attachment of the electrodes. All patients were treated with nitroglycerine intravenously and high doses of heparin and, in several cases, nifedipine as well. Some patients received thrombolytic therapy with streptokinase. Despite therapy, 21 ischaemic attacks were documented in five patients. Seventeen attacks were seen in patients with acute infarction but who were not treated with streptokinase. All attacks were accompanied by chest pain. The duration of ischaemia ranged from 18 to 87 min. Several attacks were stopped immediately by therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗
PubMed1983

[Atloido-axoid surgery by a transoral approach].

The author has approached 18 atlanto-axial joints in 15 years by a transoral approach. Fourteen of the lesions were post traumatic, two congenital, one rheumatoid and one a tumour. It is concluded that the approach is a valuable one provided that there is adequate surgical technique, good antiseptic preparation, antibiotic therapy, provisional peroperative tracheostomy and special retractors. Use of adequate suture is also important. In some cases, magnification was needed. Medullary monitoring may also be helpful. The author estimates that the approach is more effective than extrabuccal techniques since it allows a direct exposure of the lesion. Large excisions are possible followed by reconstruction and grafting. It also allows screw fixation of the odontoid process. Two patients among earlier cases became infected but without serious long-term complications. Remaining cases have uncomplicated follow-up.

Adult↗
PubMed1979

[Polyarteritis nodosa with ureteric stenosis. Two cases (author's transl)].

In two cases, surgical exploration fully confirmed that ureteric stenosis was related to PAN. There are four cases of this association in the litterature but it is probable that the frequency of such stenosis is underestimated: amongst 75 patients being treated for PAN in our department, only 11 underwent intravenous urography, 10 being abnormal.

Adult↗
PubMed1979

[Cervical spine. II. Fractures and dislocations (author's transl)].

Clinical and radiologic investigations in spinal fractures and dislocations must allow assessment of modifications in osteoarticular and neural functions. With respect to osteoarticular function it is necessary to identify the presence of both temporary or permanent instability and impaired static equilibrium. Regarding neural functions we must not only evaluate the neurologic damage but also residual stenosis of the spinal canal and sometimes of the intervertebral foramina. Compression induced by such stenosis is best demonstrated on métrizanide myelography. Management is currently aimed at better and more rapid correction of morphologic damages and disturbed stability. These goals are achieved by reduction and stabilisation using orthopedic or surgical techniques, the later involving an anterior or posterior approach to osteosynthesis. Systematic suppression of factors causing neural compression has led to a greater recovery rate than in the past.

Cervical Vertebrae↗
PubMed1979

[Cervical sprains and cervical herniated discs (author's transl)].

The cervical spine, containing twenty-articulations, is particularly exposed to sprains. Benign cases are those in which both spinal stability is not affected and only subjective neurovascular complaints are present. Management essentially involves constant volontary immobilization of the cervical spine with or without apparatus (Postural training). The severity of the sprains results from the possibility of either vertebral instability or objective neurovascular complications. Bony instability can be detected on dynamic radiographs based on precise criteria defined by physiologic study of normal spinal movements. When a persistant vascular syndrome involving the vertebro-basilar arteries is observed, vertebral arteriography may be indicated. Likewise, the presence of a thoracic outlet syndrome may required sub-clavian arteriography. Metrizamide myelography is used to explore neurologic lesions. The author concluded that only severe cervical sprains required surgical intervention. A prolapsed cervical disc, revealed by discography and especially metrizamide myelography, most often requires an anterior approach to surgery.

Cervical Vertebrae↗
PubMed1979

Anatomo-radiological considerations about lumbar discography. An experimental study.

An experimental study was undertaken to determine the origin of lumbar pain associated with degeneration of lumbar intervertebral disc by examining their innervation, vascularization, and stages of evolution. The study included the comparison of discography on patients with an experimental reproduction of this examination on cadavers.

Adolescent↗