Posterior Instrumented Correction Without Arthrodesis in Adolescent Idiopathic Scoliosis: A Case Report

Posterior instrumentation with arthrodesis is the established surgical treatment for progressive adolescent idiopathic scoliosis (AIS). We report a case of severe AIS corrected using segmental pedicle screw instrumentation without arthrodesis and critically examine the rationale and implications of this approach. A 17-year-old skeletally mature female (Risser grade 5) presented with progressive trunk deformity and intermittent back pain. Standing radiographs demonstrated a 65° right main thoracic curve from T5 to L1 with an apex at T9 and a 35° proximal thoracic curve (Lenke 2AN). The major curve corrected to 15° on right side-bending. Magnetic resonance imaging (MRI) excluded intraspinal pathology, and pulmonary function testing showed a mild restrictive pattern. Posterior instrumentation from T3 to L1 was performed using 14 fluoroscopy-assisted pedicle screws (implant density, 1.27 screws/level). Correction was achieved by rod rotation without osteotomy, and no decortication, bone grafting, or arthrodesis was performed. The decision to avoid fusion was made to eliminate iliac crest donor-site morbidity. Intraoperative neuromonitoring was not used; a Stagnara wake-up test after correction was normal. Operative time was four hours, with 250 - 300 mL blood loss and no transfusion. The major curve measured 10° immediately postoperatively. The patient mobilised on postoperative Day 2 and was discharged on Day 5. At 18 months, coronal alignment remained maintained without adverse events, and she had returned to light sporting activity. Although this case demonstrates that severe AIS can be corrected and maintained in the short term with instrumentation alone, the rationale for omitting arthrodesis is debatable because local autograft can be obtained without iliac crest donor-site morbidity. Moreover, without a fusion mass, the implants remain responsible for maintaining correction indefinitely, potentially increasing the risk of late fatigue failure. Eighteen-month follow-up is insufficient to establish durability. This case should therefore be regarded as an observation warranting long-term surveillance rather than evidence of a validated alternative to arthrodesis.