Das laterale Profil der Lendenwirbelsäule nach lumbosacraler Spondylodese - Vergleich zwischen Harringtonstäben und einem transpedikulären Fixationssystem (USIS nach Zielke)

: We compared the lateral profile of the lumbar spine after lumbosacral dorsal fusion in two groups of each 32 patients with comparable age, sex distribution and indication; one group had been fused with the use of two short Harrington rods, the other with the Universal Spinal Instrumentation System (USIS) according to Zielke/Harms. The sparing of motion segments using a transpedicular system is demonstrated by the average number of 1.7 fused motion segments compared to 2.2 with the Harrington rods. The average increase of cyphosis of the fused area could be reduced with USIS from 7.3 to 3.0 degrees in spite distraction. The greatest difference could be seen in cases of spondylolisthesis (2.0 degrees compared to 8.2) and in fusions including three segments (2.0 versus 7.0). No significant difference in total lordosis of the lumbar spine could be evaluated and there was no influence of preoperative mobility on the grade of postoperative cyphosis. The early results of lumbar fusion using USIS are clinically satisfying in spite of a relative high rate of rod fracture. measures to achieve a higher stability and diminish the rate of implant failure are discussed.