Convex instrumented hemiepiphysiodesis with concave distraction: a preliminary report.
Complex spinal anomalies involved in congenital scoliosis consist of a jumble of vertebral defects. Progressive scoliotic curves are frequently encountered in these patients. We evaluated the results of hemi-epiphysiodesis for this patient population. A series of ten patients with unclassified scoliosis, involving multiple hemivertebrae and/or bars, was reviewed retrospectively. Hemi-epiphysiodesis was the primary treatment in all patients. Mortality, complications and wound healing problems did not occur. The average Cobb angle for all patients changed from 54° (range: 40°–74°), preoperatively, to 58° (range: 30°–104°), postoperatively. Applying the criterion of a minimum change of 20°, to take into account measurement variability, an epiphysiodesis effect was achieved in two procedures, progression was arrested in six procedures and failure occurred in two procedures. The mean rate of Cobb angle change per annum decreased from 2.9° (range: –35° to 14°), preoperatively, to 2.4° (range: –4° to 13°), following surgery. Repeat surgery was necessitated by coexisting progressive kyphosis and pseudoarthrosis in one patient, and involved extension of primary epiphysiodesis in two patients. A mean intervention-free period of 58 months was established. These results suggest that hemi-epiphysiodesis stabilized the unclassified congenital scoliosis. Being under 5 years of age, having a thoracolumbar curve location, and the absence of coexisting kyphosis were found to be associated with a more favorable outcome.