Active Apex Correction (APC) for Early Onset Scoliosis. Early Results of a Pilot Study.

Early onset scoliosis (EOS) presents a significant clinical challenge due to progressive spinal deformity during critical periods of spinal and thoracic growth. Inadequate management may result in thoracic insufficiency, impaired pulmonary development, and long-term cardiopulmonary morbidity. Achieving deformity control while preserving spinal growth remains the primary treatment goal.

Conservative strategies such as bracing and serial casting may delay progression but are often insufficient, necessitating surgical intervention.Early definitive spinal fusion arrests spinal growth and causes truncal shortening.

Growth-friendly, non-fusion techniques preserve spinal growth while controlling deformity. Traditional growing rods (TGR) require repeated surgical lengthening, resulting in high complication risks including infection, implant failure, and unplanned reoperations. Repeated distractions may lead to unintended spinal autofusion, compromising growth potential. Magnetically controlled growing rods reduce repeated surgeries but remain costly with mechanical failure risks. The Shilla system allows spinal growth but faces loss of correction and implant failure.

Active Apex Correction (APC) is a relatively novel growth-friendly surgical technique, first innovated approximately 16 years ago, gaining increasing international interest recently. APC, a Shilla modification, addresses limitations of existing growth-preserving strategies. APC employs a single surgical procedure with unilateral convex-side compression at the curve apex, allowing guided spinal growth while avoiding concave-side instrumentation, osteotomies, and repeated lengthening procedures. This approach may reduce operative time, implant density, infection risk, and treatment cost. However, despite theoretical advantages, clinical data on APC remain limited. Therefore, evaluating radiographic correction, growth preservation, and clinical outcomes with APC is necessary to define its role in managing EOS.