The authors describe a technique of percutaneous interbody osteosynthesis applicable to the dorsal and lumbar spine. 51 patients were so treated for different aetiologies: traumatic conditions (35 cases) and tumoural lesions (16 cases). The material used consisted of special instruments that are positioned in double obliquity by a percutaneous posterolateral approach. A posterior approach limited to the pathological focus was used jointly whenever a graft or a decompression was necessary (19 cases). Several types of anaesthesia were used (local, local-regional, general, neuroleptanalgesia). The patients benefited by the advantages that usually accompany percutaneous techniques. The advantages and limitations of the method are discussed.

The authors report their experience with 150 cases of discectomies performed with interbody grafts using a copolymer (Biocompatible Orthopedic Polymer or BOP). Made of N-Vinylpyrrolidone-Methylmethacrylate monomers, polyamide fibres and calcium gluconate. BOP is a biocompatible, biodegradable, osteoconductive matrix, easy to use and quite safe. These properties are quite well appreciated for cervical interbody grafting. After discectomy, stabilization of the spine is immediate, and fusion slowly occurs around and through the biopolymer within one year. The biomaterial avoids morbidity inherent in the harvesting of an autograft, as well as any limitations resulting from the use of allografts.

The authors report a new technique for percutaneous surgery of thoraco-lumbar discs. It allows nucleotomy or intersomatic grafting. This extra-articular posterolateral approach is performed under fluoroscopic monitoring by using a Kirschner's wire and some specific co-axial tubes. Scanographic polar coordinates are most suitable for valuable locating of thoracic discs and performing of technique. Indications and limits of the method are discussed with preliminary results obtained with the first 19 cases.

The authors describe a new technique for treatment fractures of the dens. An anterior approach (technique of Boehler) is used. It provides for one-stage fusion and no additional disturbance of C1-C2 rotation. Under AP and lateral guidance the body of C2 is drilled medially, and so are the site of fracture. Then comes the gradual impaction of a conical implant of biocompatible resorbable implant [*], tip cephalad. The biopolymer is used for grafting purposes in all type of fractures of the odontoid process, which permits the latter to be fused without using screws or any other metal implant.

The authors report a new approach of the intervertebral foramen using a conservative hemi-transverso-arthro-pediculotomy. It allows to remove one half of the posterior neural arch and to follow the nervous bundle from its origin to the extra-foraminal space. Removal of the foraminal disc herniation is easy and safe. The monobloc is replaced to prevent any instability.

The authors report their experience in the treatment of 15 cases in thoracolumbar metastases with spinal cord compression. A decompressive laminectomy was routinely performed and followed by a transversoarthropediculectomy. Most part of the neoplastic tissue was removed from the epidural space, vertebral body and retroperitoneal or retro-pleural areas. Complete decompression of the nervous elements was always achieved. Stabilization was obtained by replacement of the neoplastic vertebral body with a methylmetacrylate prothesis and eventually by Kempf s compression instrumentation. The surgical treatment was completed in a single stage operation, by a classical posterolateral approach. Orthopaedic, neurologic and oncologic advantages of this treatment are discussed.

The authors report a case of cervical chondroma presenting with a syndrome of spinal cord compression in a 76-year-old woman. Total surgical removal of the lesion was followed by partial neurological recovery. Chondromas of the vertebral column are rarely reported in the literature.

In 1984, Aoki reported a new technique for treatment of chronic subdural hematomas in adults. This simple, effective technique and least invasive procedure lead us to use it. Our data seems encourageous as they were previously reported by Aoki.

The amnesic syndrome is analysed in 6 infarctions restricted to the thalamic area. Bilateral lesions were linked to more definite deficits; the anterograde forgetting was unequivocal at the initial stage and affected both verbal and visual memory. In unilateral lesions, deficits were far more discrete and there was no evidence enough for assuming a strict hemispheric specialisation, left for verbal memory, and right for visual memory. These cases and others from the literature suggested that amnesia is more important and pure in infarctions of the anterior part of the thalamus.

Le syndrome amnésique est analysé dans 6 infarctus restreints de la région thalamique. Les lésions bilatérales s'accompagnaient des déficits les plus francs; l'oubli à mesure n'était net qu'à la phase initiale et touchait la mémoire verbale et la mémoire visuelle. Dans les lésions unilatérales, les déficits étaient beaucoup plus discrets et il n'y avait pas d'argument suffisant pour démontrer une spécialisation hémisphérique stricte, gauche pour la mémoire verbale, droite pour la mémoire visuo-spatiale. Ces cas et les autres de la littérature évoquaient que l'amnésie est plus importante et plus pure dans les infarctus touchant la partie antérieure du thalamus. The amnesic syndrome is analysed in 6 infarctions restricted to the thalamic area. Bilateral lesions were linked to more definite deficits; the anterograde forgetting was unequivocal at the initial stage and affected both verbal and visual memory. In unilateral lesions, deficits were far more discrete and there was no evidence enough for assuming a strict hemispheric specialisation, left for verbal memory, and right for visual memory. These cases and others from the literature suggested that amnesia is more important and pure in infarctions of the anterior part of the thalamus.