[Surgical treatment of isthmic spondylolisthesis. A comparative study of 3 types of arthrodesis].

The authors present a series of 186 cases of spondylolisthesis treated using 3 different types of arthrodesis: 84 by anterior arthrodesis, 35 by postero-lateral arthrodesis and 67 by combined arthrodesis. Slippage reduction was sought only in combined arthrodesis. The elimination of pain or a significant improvement were noted in 95 per cent of cases treated by anterior arthrodesis, in 74 per cent of those treated by postero-lateral arthrodesis and in 97 per cent of those treated by combined arthrodesis. The work resumption or professional rehabilitation rate was 89 per cent for anterior arthrodesis, 46 per cent for postero-lateral arthrodesis and 90 per cent for combined arthrodesis. Analysis of the clinical results according to the criteria of Stauffer and Coventry shows that good results were noted in 69 per cent of cases treated by anterior arthrodesis, in 43 per cent of those treated by postero-lateral arthrodesis and in 74 per cent of those treated by combined arthrodesis. A fusion rate of 86 per cent was achieved after anterior arthrodesis, 69 per cent after postero-lateral arthrodesis and 95 per cent after combined arthrodesis. Reduction had no effect on either clinical results or spinal statics in spondylolisthesis of less than 50 per cent. In the reduction of spondylolisthesis of more than 50 per cent, better results were obtained with the R. Louis technique than the Harrington technique in the restoration of spinal statics and maintenance of long-term clinical results.