[Long-term treatment outcome in ventral and combined ventrodorsal spondylodesis in the surgical therapy of scoliosis].

We report on 48 patients with a mean postoperative follow-up of 7.7 years. 9 patients underwent simple anterior derotation spondylodesis (VDS), 31 patients were additionally fused with posterior Harrington spondylodesis. In 7 of 8 patients the Dwyer compression spondylodesis (DCS) was completed with the Harrington instrumentation. 2 of 3 scoliosis were idiopathic, the residual cases were mainly neuromuscular. The primary curve (preoperative mean: 69.9 degrees) was initially corrected by 62.8% and sustained a loss of correction of 7.6 degrees resp. 10.9% during long-term follow-up. The long-term loss of correction was maximal after DCS showing 10.4 degrees (14.4%), on the average, and minimal after combined VDS and Harrington spondylodesis showing 6.9 degrees (9.3%). After simple VDS the long-term progression of the curve was 7.0 degrees (12.9%). In this group the initial correction was above-average high showing 76.4%. The main loss of correction occurred during the first 2 years after surgery. The long-term correction stability did not show significant differences between simple VDS and combined antero-posterior instrumentation. After anterior instrumentation of the primary curve the secondary cranial nerve spontaneously straightened up by 30%, on the average, and remained stable in the long-term. The anterior instrumentation of the spine lead to a mean loss of lordosis of 13.6 degrees which in the long-term additionally increased by 6.4 degrees due to the anterior epiphyseodesis effect. In 17 patients (42.5%) 24 fractures of the 3 mm-threaded VDS-compression rod occurred. In case of single rod fractures no higher loss of correction or differences in incidence of pain were observed in comparison to intact implants.