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Objectives and questions: The correction of rigid adolescent idiopathic scoliosis (AIS) is challenging. In addition to the deformity, the rib hump has been shown to impose a significant burden on patients, both in terms of functionality and aesthetics. The improvement of the sagittal profile is a particularly arduous task. In order to achieve a visually appealing result, we propose the implementation of a concave thorakoplasty (CTP). It has been demonstrated that this approach facilitates the correction of rigid thoracic scoliosis, whilst concomitantly reducing secondary thoracic deformity. However, the extent to which this procedure contributes to an advanced correction of the sagittal profile remains unclear.

Material and methods: This study constitutes a retrospective evaluation of pre- and postoperative X-rays, with a follow-up period of one year. Patients with AIS who underwent posterior spinal correction with CTP were included in the study. Following dorsal release and placement of pedicle screws, the rods were temporarily fixated. As part of the CTP, the ribs at the apex of the scoliotic curve were mobilized through osteotomy and then fixated to the corresponding rod on the same side using non-absorbable sutures. The following radiological measurements were conducted on all X-rays: Cobb-angle (CA), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), spino-sacral-angle (SSA), sagittal vertical axis (SVA), proximal kunction kyphosis (PJK).

Results: Thirty-five patients were included. The average age was 25.5 years ± 13.3 with 27 females and 8 males. The Lenke types were as follows: Type 1 (n=17), type 2 (n=2), type 5 (n=14), type 6 (n=2). On average the length of instrumentation was 12.3 vertebrae and CTP of 5.8 ribs. The average preoperative CA was 80.4° ± 15.5. The average postoperative CA was 34.6° ± 9.2, the average CA in the follow-ups was 35.3° ± 8.8. Hereby providing a correction rate of 56%. Statistical analysis revealed significant differences between pre- and postoperative values for LL, CA and PJK (p<0.0001). The ICC showed good reliability.

Discussion and conclusions: These results demonstrate that dorsal correction combined with CTP is an effective approach for the treatment of rigid thoracic scoliosis. Despite the initial deformity characterized by rigid thoracic segments, the surgical outcome is to be considered highly satisfactory. Compared to similar studies, correction rates for LL, CA, PJK achieved in this cohort were notably higher. In addition, a moderate enhancement of the aforementioned spinopelvic parameters and lesser adjacent segment disease is to be anticipated. As expected, there was no significant improvement in TK. This phenomenon is primarily attributable to two factors. Firstly, to the partially grotesque rotational deformity. Secondly, the higher age average of the cohort understudy. A further study has been conducted incorporating the evaluation of patient satisfaction.