[Comparative tridimensional mechanical study of external fixation devices. Clinical deductions].

A tridimensional mechanical study has been carried out to compare the stabilization achievable with three types of fixators: the Ilizarov, the Orthofix and the French Army External Fixator (FESSA). The Ilizarov allows a noticeable instability persisting in every spatial plane with the exception of transverse movements. Cumbersome and unstable, this device does not seem suitable for the treatment of open fractures especially in adults.

[Carpal instability. Diagnostic considerations and clinical study].

The clinical picture of carpal deviations is far from evocative and diagnosis is uniquely radiographic. Clinical features become reliable when intermittent malalignment of the carpal articulations leads to instability: the trick wrist is an example. The measurement of the radiolunar angle on a neutral position lateral view of the wrist is sufficient in the screening for carpal instabilities.

[A comparative mechanical study of types of external fixator (author's transl)].

The authors have designed and original type of external fixator which can be used in the forces in case of armed conflict. Study has been directed towards a simple, strong and inexpensive apparatus which can be applied in emergency circumstances. Secondarily it can be replaced by another apparatus to allow compression, distraction or better reduction of a fracture without removal of the pins.

[Osteosynthesis by adherent plates. An experimental physical study].

The creation of ridges of the deep surface of plates used for osteosynthesis increases their adherence to bone. By increasing the coefficient of friction between the plate and the bone, the stresses taken by the screws can be diminished by a third. The procedures diminishes by the same amount the risk of stripping or loosening of screws and thus the risk of pseudarthrosis.

[Approaches to the semilunar bone and their indications].

The authors review incisions for exposure of the lunate bone and describe them in detail. They study the advantages and disadvantages of each approach, then consider their indications in peri-lunar luxation, scapholunar luxation and Kienboeck's disease. They emphasize the interest of the palmar routes in all cases, except for scapho-lunar luxation.