ObjectiveTo observe the medium-term clinical and radiological outcomes of anterior release internal distraction in treatment of severe and rigid scoliosis. MethodsBetween March 2009 and March 2012, 26 patients with severe and rigid scoliosis were treated with anterior release, posterior internal distraction, and two stage posterior spinal fusion. There were 11 males and 15 females with an average age of 19.6 years (range, 14-25 years). The average disease duration was 13.6 years (range, 3-24 years). All cases were idiopathic scoliosis. Of 26 cases, 2 cases were rated as Lenke type I, 8 as type Ⅱ, 13 as type IV, 1 as type V, and 2 as type VI. The apical vertebrae located at T6 in 1 case, at T7 in 3 cases, at T8 in 7 cases, at T9 in 13 cases, and at T10 in 2 cases. The average 4 vertebral bodies were released by anterior approach, and average 14 vertebral bodies were fused after posterior surgery. Fourteen patients received 2 times distraction. Scoliosis Research Society-22 (SRS-22) questionnaire was used to access health-related quality of life. The radiological parameters were measured, including coronal plane Cobb angel of major curve, apical vertebral translation (AVT), C7 plumb line-center sacral vertical line (C7PL-CSVL), sagittal vertical axis (SVA), and thoracic kyphosis (TK) at pre-and post-operation. ResultsThe average total operation time was 592.7 minutes; the average total blood loss volume was 1 311.2 mL; and total hospitalization cost was (14.7±1.4)×104 yuan RMB. The coronal plane Cobb angle of major curve was (55.7±16.5)°, and the TK was (43.2±16.2)° after first distraction. The patients were followed up 2-5 years (mean, 3.8 years). Temporary dyspnea and pleural effusion occurred in 1 case respectively after distraction, and symptoms disappeared after symptomatic treatment. Screw loosening and pseudoarthrosis formation was observed in 1 case at 6 months after fusion, good recovery was achieved after revision. No infection or neurological complication was found. The coronal plane Cobb angel of major curve, TK, and AVT after fusion and at last follow-up were significantly lower than preoperative ones (P<0.05), but no significant difference was found between at post-fusion and last follow-up (P>0.05). There was no significant difference in C7PL-CSVL and SVA between at pre-and post-operation (P>0.05). At last follow-up, SRS-22 questionnaire scores were 4.32±0.42 for active degree, 4.54±0.58 for mental health, 3.97±0.76 for self-image, 4.09±0.64 for pain, and 4.03±0.83 for satisfaction degree. ConclusionAnterior release internal distraction can provide satisfactory correction results for severe and rigid scoliosis with higher safety and lower incidence of complication.