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Biomedical subjects

H Labelle

Publications and source records attributed to H Labelle.

At least 19 recordsLinked to original sources
PubMed1992

Effect of radiographic landmark identification errors on the accuracy of three-dimensional reconstruction of the human spine.

In three-dimensional reconstruction of the human spine obtained from stereo-radiographic set-ups (two radiographs or more), it is extremely difficult to identify exactly the same landmarks on all radiographs. The effect of these identification errors was investigated with simulations made on points of known three-dimensional co-ordinates and compared with three-dimensional reconstructions of real spines obtained with the direct linear transformation algorithm. Results showed that radiographic identification errors of up to 2 mm were common, causing reconstruction errors of up to 5 mm. These reconstruction errors may be noticed in the form of geometrical inaccuracies in the graphical representation of three-dimensional reconstructions of the spine. Successive displacements were then imposed on image point co-ordinates to minimise the identification error and increase the reconstruction accuracy. The improvement on the three-dimensional reconstruction results was negligible. Three-dimensional reconstructions obtained from three radiographs were also investigated. They showed slightly more accurate reconstructions than those obtained from two radiographs. However, the increase of X-ray exposure on the patient may not be worthwhile.

Algorithms↗
PubMed1992

Lack of scientific evidence for the treatment of lateral epicondylitis of the elbow. An attempted meta-analysis.

We have reviewed 185 articles published since 1966 to assess the scientific evidence for methods of treatment for lateral epicondylitis of the elbow. Of the 185 articles, 78 discussed treatment, but since the natural history of the syndrome is uncertain we considered only those series with concurrent control groups. Only 18 of these were randomised and controlled studies. We then graded these papers for scientific validity, using the methods of Chalmers et al (1981). The mean score of the 18 articles was only 33%, with a range from 6% to 73%. A minimum of 70% is required for a valid clinical trial, and we therefore concluded that there was insufficient scientific evidence to support any of the current methods of treatment. There were too many methodological differences to allow a quantitative meta-analysis, but our qualitative review established the importance of the natural evolution of the syndrome and of the placebo effect of all treatments. Properly designed, controlled trials are needed.

Acute Disease↗
PubMed1992

[3-D study of the immediate effect of the Boston brace on the scoliotic lumbar spine].

In order to study the immediate 3-D effect of the Boston brace on lumbar scoliosis, 31 adolescents with idiopathic scoliosis King type I or II had a 3-D computerised reconstruction of their deformity with and without the brace. Results demonstrate that the brace produces a distraction of the lumbar spine similar to that produced by the Harrington instrumentation by correcting the frontal deformity at the expense of a significant reduction of the physiological lumbar lordosis. No significant effect on rotation of the apical vertebra or "detorsion" of the spine could be measured. We feel that a orthosis that provides a real 3-D correction of the deformity has yet to be developed.

Adolescent↗
PubMed1989

Running patterns of juveniles wearing SACH and single-axis foot components.

Concerns have been raised about the capability of conventional prosthetic foot components to provide adequate support and function for activities other than walking to persons with lower limb amputations. Degenerative changes of the lumbar spine and knee joints have been linked to prolonged asymmetric loading, which may be accentuated when force magnitudes are high, as in running. This study evaluated the extent and location of kinematic and kinetic asymmetries relative to the foot component worn. The running patterns of six children with unilateral below-knee amputations were evaluated on two occasions: first, while wearing the solid ankle-cushioned heel (SACH) component, and second, wearing the single-axis (SA) component. Cinematographic and forceplate data yielded bilateral temporal data, vertical ground reaction forces, joint angular trajectories, and moments. Results indicated that the SACH and SA components performed almost identically, despite the greater excursion allowed by the SA foot. Slower step speed on the affected side was related to significantly lower vertical ground reaction forces (p less than .01). The ankle angular displacement and moment curves revealed the incapacity of either component to stimulate natural foot-ankle function, with resulting significant interlimb asymmetries. The ipsilateral knee displayed marked reduction of the initial flexor wave, paired with a reduced extensor moment. Compensations predominated ipsilaterally, as evidenced by the similarity of the contralateral patterns to those of an able-bodied runner, except for a decreased hip flexor moment before toe-off. This study showed that interlimb asymmetries were attributable to the inadequacies of both components.

Adolescent↗
PubMed1988

Observer variation in assessing spinal curvature and skeletal development in adolescent idiopathic scoliosis.

Accurate measurements of spinal curvature and skeletal development are crucial in planning treatment and assessing curve progression in adolescent idiopathic scoliosis (AIS). An inter-rater agreement trial was undertaken to estimate the reliability of measuring these spinal parameters. Two orthopaedic surgeons and two trained technicians from a scoliosis clinic independently read 30 anteroposterior roentgenograms of AIS patients. Skeletal maturity was assessed using the six-point Risser sign scale, and spinal curvature was measured using the method of Cobb. Excellent agreement was observed in evaluating Risser signs (Kappa = 0.8) and primary Cobb angles (intra-class correlation coefficient, Rho = 0.98). The standard deviation of inter-observer error in measuring primary Cobb angles was 2.5 degrees, and the intra-reader error, based on one observer's reassessments of 15 films, was 1.9 degrees. Inter-rater agreement for assessing secondary Cobb angles was much lower (Rho = 0.52) because small curves (less than 20 degrees) were often not noticed. Differences in agreement between surgeons and technicians were relatively minor. These results indicate that personnel trained at this clinic are able to assess these spinal parameters reliably.

Adolescent↗
PubMed1987

Nevus sebaceus of Jadassohn: a rare oral presentation.

Nevus sebaceus of Jadassohn occurring exclusively in the oral cavity as a single lesion has not, to our knowledge, been reported previously. A case of this rare developmental anomaly at the palatine papilla of a 40-year-old woman is described.

Adult↗
PubMed1986

Nurses as a social force.

Nurses in every continent engage in social action. This, the author argues, has been a fact throughout the ages. The major social issues which contribute to health today are economic, energy, environmental and social welfare problems. Other major issues affecting health are population growth, poverty, education, clean water supply, and family planning. The author shows how individual nurses and nurses' associations can, and should, exercise their influence and power in promoting health at local, national and international levels, making primary health care a priority. By using their levers of power, together with technology and communications, nurses can help create a new world health order, the author concludes.

Canada↗
PubMed1986

Natural history of scoliosis in Friedreich's ataxia.

Does scoliosis associated with Friedreich's ataxia behave like an idiopathic or a typical neuromuscular scoliosis? Should it be treated like an idiopathic or a neuromuscular curve? Since no precise information to answer these questions could be found in the orthopaedic literature, a retrospective study was undertaken of seventy-eight patients with Friedreich's ataxia who had been followed at our neuromuscular clinic. Fifty-six of these patients were found to have typical Friedreich's ataxia in accordance with the criteria of Geoffroy et al., and their cases were retained for analysis. Their mean age was twenty years (range, eight to thirty-three years). The average length of clinical follow-up was nine years and the average duration of radiographic follow-up of the scoliosis was 3.5 years. A scoliosis of more than 10 degrees was found in all patients and was associated with a hyperkyphosis in 66 per cent. Both sexes were equally affected. Fifty-seven per cent of the curves were double thoracic and lumbar; 14 per cent were thoracolumbar; 7 per cent, double thoracic and thoracolumbar; 7 per cent, thoracic; 4 per cent, lumbar; and 11 per cent, multiple small curves. Of the fifty-six patients whose cases were studied, thirty-six had been followed for at least ten years. Among these thirty-six, there were twenty whose curves were more than 60 degrees and progressed (Group I) and sixteen whose curves were 40 degrees or less and did not progress (Group II).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1978

Nursing authority.

Explore the source record for details and available documents.

Authoritarianism↗
PubMed1978

The abnormal lateral patellofemoral angle: a diagnostic roentgenographic sign of recurrent patellar subluxation.

On roentgenograms made with the patient supine, the knees flexed 20 to 30 degrees, the x-ray tube between the ankles, and the cassette held proximal to the knees and perpendicular to the x-ray beam, it was found that a line between the femoral condyles and a line between the margins of the lateral facet of the patella formed the lateral patellofemoral angle, an angle that was of diagnostic value in patients with subluxation of the patella. In 100 clinically normal patients, these lines were parallel in three and formed an angle open laterally in ninety-seven. In thirty patients with subluxation of the patella, the lines were parallel in twenty-four and formed an angle open medially in six. In 100 patients with chondromalacia of the patella, however, the roentgenographic study was of no diagnostic value since the lines were parallel in ten and formed an angle open laterally in ninety.

Female↗