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SPINAL İMBALANCE AND DECOMPENSATION PROBLEMS İN PATIENTS TREATED WITH COTREL DUBOUSSET INSTRUMENTATION

  • I. Teoman BENLİ
  • Mert TÜZÜNER
  • Mahmut KIŞ
  • Reha TANDOĞAN
  • Mehmet ÇITAK

J Turk Spinal Surg 1994;5(3):94-101

Current principles of idiopathic scollosis treatment are three dimenslonal correction and rigid fixation. Although it is accepted that the Cotrei - Dubousset Instrumentation (CDI) meets these goals, there is concern about the po-tential risk of trunk imbalance and spinal decompensation during the derotation manouvre. The results of 45 pa-tients with idiopathic scoliosis treated with CDI between December 1988 and August 1992 were retrospectively anaiyzed. Mean age was 14.3 years and mean follow up wa 48.6 months. Average of 49.6% correction ıvas achieved in the majör curves. The best results were obtained in King Tip III curves with a 69.4% correction. Spinal imbalance was evaluated by measuring Lateral Trunk Shift (LT), Shift of Head (SH) and Shift of Stable Vertebra (SS). Decompensation was measured by the increases in secondary curves. When aiicurve types were included, the average preoperative LT value of 1.96 Vertebral Units (VU) was brought down to 0.91 VU postoperativeiy, achieving a 55.9% correction. Fourteen patients had a SH of zero preoperatively and remained balanced after in-strumentation. Of the 41 remaining cases, 21 became zero postoperativeiy. When ali cases were included the average preoperative SH was 1.0 VU and was corrected to 0.42 VU with CDI (69% correction). An average of 75.5% correction was obtained in SS, and the mean preoperative value of 0.73 VU was corrected to 0.19 VU. At the last follow-up visit a secondary curve had formed above the majör curve in one case and three patients had a junc-tional kyphosis. Loss of correction in the frontalplane was corelated with loss in the correction of LT. The rigid and semi-flexible lumbal curves had a tandency to progress when they were not instrumented, especially in Type II curves. Junctional kyphosis could be prevented when concave laminar claws were used in the thoraco-lumbal region. İt was concluded that spinal decompensation and imbalance could be minimized with careful preoperative planning, avoidance of over-correction and a long instrumentation in double majör curves.

Keywords: İdiopathic Scoliosis, Spinal İmbalance, Decompensation.