[The evaluation of the Harrington technique in the treatment of double-curved scoliosis (author's transl)]. / Evaluation de la technique de Harrington dans le traitement des scolioses doubles.

Double-curved scoliosis was present in 18.5 of 750 scolioses operated on at the St. Justine Hospital in Montreal. 128 cases were reviewed with a follow up of more than 3 years. Pre-operative curves measured 61 and 58 degrees on average and post-operative curves measured 27 and 23 degrees. At the time of review, the curves were 39 and 36 degrees. The loss of correction varied with the age of the patient and the severity of deformity. The technique of early ambulation improved the post-operative results. However, it was concluded that compression rods did not provide a better correction of the curve or of the thoracic kyphosis.

Impaired muscle differentiation in explant cultures of Duchenne muscular dystrophy.

Muscle cultures were established from 11 normal controls and 13 Duchenne muscular dystrophy biopsies by an explant technique. Under light microscopy the most distinctive features of Duchenne muscular dystrophy cultures were an earlier migration and a delay or even an absence of fusion of mononucleated cells in comparison with the controls. Furthermore, most fusing dystrophic cells were morphologically different from conventional myoblasts, and, at a later stage, myotube formation was significantly reduced. In contrast to controls, dystrophic cultures displayed a total absence of spontaneous contractions and poor myofiber longevity. Atypical myogenic cells seen in Duchenne muscular dystrophy cultures differed ultrastructurally from normal myoblasts in having a smaller population of free ribosomes and polyribosomes, prominent rough endoplasmic reticulum, and abundant intermediate filaments. The dystrophic myofibers that had reached relative maturity always exhibited a poorly developed contractile apparatus in contrast to structurally well-defined normal myofibers. It is inferred that the impaired myogenesis observed in Duchenne muscular dystrophy cultures results primarily from defective fusion involving atypical myogenic cells.

[Moderate hypobaric hypoxia used as an inducer of congenital vertebral malformation in mouse embryo (author's transl)]. / L'hypoxie hypobarique modérée, comme inducteur des malformations vertébrales congénitales chez l'embryon de souris.

In 1976, we decided to review the files of the scoliosis clinic at Ste-Justine Hospital in Montreal. We found 2,237 patients with scoliosis, 212 of them are classified as congenital. At this time, congenital scoliosis were the major unresolved problems. We decided to look at an experimental model, to study the physio-pathological mechanism of the induction of these malformations. We chose the mouse as the experimental animal, and "hypobaric hypoxia" as the teratogenic agent. With this model, we can produce, malformations at different levels of the spine, if we treat at different days of pregnancy. For example, if we treat the mothers in the 10th day of her pregnancy, we get 90% of malformed embryos, at the lumbar level. All the malformations reproduced in the mice, are similar to those found in humans. We have also demonstrated no difference in the morphology of these malformations from birth to maturity, in contradiction with Epstein, who said that the majority of cleft vertebrae will disappear with bone maturation. We have also demonstrated that these malformations are present in the cartilaginous stage of development of the vertebral column. Our findings are in contradiction with Nassim's who stated, that congenital vertebral malformations are produced by an abnormal ossification process on a normal cartilage primum. Finally, our findings are in agreements with those of Dr. Uhthoff, who showed that congenital vertebral malformations are present in cartilaginous stage of development in human embryos.

[Treatment of idiopathic scoliosis by the Harrington technique. Experience from the Ste-Justine Hospital, Montreal]. / Traitement de la scoliose idiopathique par la technique de Harrington. Expérience de l'hôpital Sainte-Justine, Montréal.

The purpose of this study was to evaluate the first seven hundred and fifty cases of scoliosis treated surgically by the harrington technique at Ste-Justine Hospital for Children in Montreal since 1964, in regards to modifications of original technique. Five surgeons were involved in the treatment. The mean presurgical angulation was 57.9 degrees; the mean post-surgical angulation was 20 degrees representing an immediate gain of 37.9 degrees. Average loss of correction three years after surgery was 13.3 degrees. Hibbs and Moe type of posterior spine fusion with fresh autogenous iliac bone appears to be the best procedure for maintenance of initial correction, together with early ambulation in a well-molded Risser-Cotrel type of plaster jacket. Prognosis as related to percentage of retained correction is better in girls than boys and also when fused after the age of thirteen years. More correction was obtained and maintained in curves between 30 degrees and 50 degrees. Rate of neurological complications was 0.4%. There was no mortality. There were 3% rod fractures, 5% pseudarthrosis proven at surgery and 5% acute or subacute infections.