Study design: Prospective case series study.
Objective: To study the effect of percutaneous thoracoplasty-only procedure on curve pattern in mature adolescent idiopathic scoliosis (AIS).
Summary of background data: The rib hump prominence on the convex side is the major cosmetic concern among patients with AIS. Thoracoplasty combined with spinal fusion is a commonly used procedure in scoliosis. However, there are no studies regarding the effect of isolated thoracoplasty procedure on curve pattern in skeletally matured patients with AIS.
Methods: The study involved 7 skeletally matured female patients with AIS. The convex rib hump deformity was measured preoperatively using hump height and hump angle. We performed thoracoplasty without spinal fusion in patients with the Cobb angle less than 40° but with prominent hump deformity. Thoracoplasty was performed percutaneously using 1 or 2 transverse incisions along the rib hump, and apex portions of the deformed ribs were resected. The Cobb angle was measured before surgery, immediately after surgery, and at final follow-up visit. In all cases, clinical satisfaction was assessed using the Scoliosis Research Society Instrument (SRS-22 questionnaires) and trunk appearance perception scale before surgery and at final follow-up visit.
Results: The mean patient age was 20.24 years and an average of 4 ribs were resected. The mean preoperative hump height and hump angle of 38.14 mm and 14.14° improved to 11.70 mm and 11.42° respectively, after surgery (P = 0.018 and 0.042). Preoperative and the final follow-up mean Cobb angles were 35.43° and 45.00°, respectively (P = 0.028). On average, the mean thoracic curve progressed by 9.57°. Preoperative Scoliosis Research Society Instrument SRS-22 questionnaires and trunk appearance perception scale scores of 4.09 and 2.57 respectively improved to and 4.26 and 3.66 after surgery (P = 0.126 and 0.014).
Conclusion: Percutaneous thoracoplasty-only procedure gives significant rib humps correction and satisfactory clinical outcome. However, progression of the curve was observed after surgery. This suggests that the convex ribs function as a buttress for curve progression.