[The treatment of congenital tibial pseudarthrosis]

Congenital tibial pseudarthrosis (CTP) remains one of the most challenging problems in paediatric orthopaedic surgery. With the abandonment of older grafting techniques in favor of vascularized fibular transplants or the Ilizarov method the final outcome has improved and made the prognosis for patients less cumbersome. Using the latter technique in 10 patients, a success rate of 90 % could be reached. Nevertheless, although solid healing occurs in most of the patients nowadays, this is often at the cost of multiple operations before a definite well united, equalized and normally aligned limb can be obtained.

Treatment of nonunion of the humerus using the Ilizarov external fixator

Ilizarov's method of monofocal compression was used in 30 humeri with a diaphyseal pseudarthrosis. Twenty-one patients had previous surgery but had loosening of the osteosynthesis material. Nine patients initially were treated with a hanging cast, resulting in interfragmentary distraction. Fourteen nonunions were hypertrophic, and 16 were atrophic, of which six were infected. A complete circular frame was used only in the first nine patients, whereas the remaining 21 patients were treated with the modified semicircular fixator. Union was obtained in all but two patients, with an average consolidation time of 4.5 months (range, 2.5-10 months). No patient required additional bone grafting. Apart from superficial pin tract infection seen in most of the patients, three had a minor temporary sensory neurologic problem. Four patients experienced a second fracture after removal of the fixator that required a second application of an Ilizarov frame. Although similar results with regard to union are reported after plate osteosynthesis, there was no radial nerve palsy or deep infection in this series, indicating that the treatment by the Ilizarov technique is associated with less complications. The authors' findings suggest that the Ilizarov method is a reliable treatment for humeral nonunions, even after multiple previous operations or in the event of infection.

Idiopathic scoliosis instrumentation using the Lea Plaza sublaminar frame. A preliminary report

We reviewed 28 patients with idiopathic scoliosis operated on using the segmental sublaminar instrumentation devised by Lea Plaza. The results at 2 years show that the spine is rebalanced and normal alignment in the sagittal plane is obtained. The biplanar correction of double curves averaged 64% with a loss of 10% at 2 years. The upper and lower limits of the fusion area must be determined accurately in relation to the pattern of the curve. Combined anterior and posterior arthrodesis is advised in flexible or rigid curves of more than 60 degrees in skeletally immature or mature patients respectively. In double curves over-correction of the primary curve behind its flexibility index, and inclusion of the mobile transitional segments in the fusion area produce decompensation in the frontal plane. One case of total loosening of the frame occurred, but there was no protrusion of the frame, no fractures of the laminae, no sepsis, no pseudarthrosis and no permanent neural damage.

[Acrylic denture base materials in dentistry. The influence of immersion of bases on the palatal gap]

The method of experimental design, we used, is versatile enough to allow the study of immersion in water at 37 degrees C during 15 days after curing, as a new parameter able to influence the deformation of denture bases, without any additional experiment. According to the experimental conditions used to make up denture bases, this parameter can, in some cases, modify appreciably the deviation in the palate region.

[Acrylic materials for denture bases in dentistry. Study of measurement variations and the influence of three new parameters on construction of bases and their deformation]

A further study of the variance of deviation measurements of denture bases in the palate region shows that the variability of measurements is not essentially due to measuring, but also to the variability of denture processing. No more than the other previously studied parameters, the heating and cooling rates as well as the mode of insertion of resin in the cast have no effect on the dimensional accuracy of denture bases after curing.