Thoracic microdiscectomy and arthrolysis of costotransverse joint as a means of releasing technique for idiopathic scoliosis

The purpose of this study is to evaluate the effects of thoracic microdisce ctomy(anterior release) and arthrolysis of costotransverse joint(partial re section of transverse process) as additional technique in posterior procedu re for scoliosis. Subjects consisted of 11 idiopathic scoliosis patients (1 male and 10 females) aged 12 to 17 pears(average: 15.3), operated posterio rly using Co technique. The subjects were divided into 3 groups; group A: t hree patients operated without release, group B: four patients with arthrol ysis of costotransverse joint, group C; four patients with microdiscectomy of three discs around the apical vertebra and arthrolysis of costotransvers e joint, the average preoperative Cobb angle were, respectively, 56, 52 and 55 degrees. Cobb angle and disc wedge angle were measured. The correction rates of Cobb angle in the group A,B and C were 77%, 65%, and 53%, respecti vely. Improvement in the disc wedge angle was obtained especially in-group A. Microdiscectomy appeared to be effective to de-stabilize the thoracic cu rve. This additional technique provide excellent correction in one stage po sterior procedure. Concerning to the arthrolysis of the costotransverse joi nt,more detailed study and biomechanical examination are needed for accurat e evaluation.