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

Overview

The primary objective of this study is to evaluate the early results of Active Apex Correction (APC) technique for managing early onset scoliosis.

Detailed description

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.

Interventions

• Procedure Active Apex Correction (APC)
  • Active Apex Correction (APC) begins with the identification of the curve apex and the selection of upper and lower "foundation" vertebrae, where pedicle screws are placed on the convex side only, above and below the most wedged vertebrae. No screws are inserted on the concave side, avoiding the need for osteotomies at the apex. The rods are then connected to both upper and lower foundation constructs, contoured to maintain appropriate sagittal alignment.

Primary outcome measures

• Spinal Length Correction (T1-T12 and T1-S1) in millimeters. [Time frame: At latest follow-up (1 year postoperative)]

Secondary outcome measures (3)

• Percentage of correction of the primary curve (%). [Time frame: one year postoperative]
• Thoracic Kyphosis Angle (Cobb Method) in degrees [Time frame: one year postoperative]
• Number of Participants with Postoperative Complications. [Time frame: one year postoperative]

Eligibility criteria

Inclusion criteria

• All patients with progressive early onset scoliosis (congenital, idiopathic, neuromuscular or syndromic).
• Major curve Cobb angle ≥ 40°
• Child below 10 years of age or less than Risser grade 2
• No prior scoliosis surgery

Exclusion criteria

• Age above 10 years or more than Risser grade 2.
• Operated EOS cases indicated for revision.
• Active infection or systemic illness precluding surgery.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

N/A

Model

Single group

Masking

Open label

Primary purpose

Treatment

Study locations

Egypt · 1 center

• Assiut University Hospital — Asyut

Publications

• Williams BA, Matsumoto H, McCalla DJ, Akbarnia BA, Blakemore LC, Betz RR, Flynn JM, Johnston CE, McCarthy RE, Roye DP Jr, Skaggs DL, Smith JT, Snyder BD, Sponseller PD, Sturm PF, Thompson GH, Yazici M, Vitale MG. Development and initial validation of the Classification of Early-Onset Scoliosis (C-EOS). J Bone Joint Surg Am. 2014 Aug 20;96(16):1359-67. doi: 10.2106/JBJS.M.00253. PMID 25143496
• Kim G, Sammak SE, Michalopoulos GD, Mualem W, Pinter ZW, Freedman BA, Bydon M. Comparison of surgical interventions for the treatment of early-onset scoliosis: a systematic review and meta-analysis. J Neurosurg Pediatr. 2022 Sep 23;31(4):342-357. doi: 10.3171/2022.8.PEDS22156. Print 2022 Sep 1. PMID 36152334
• Latalski M, Fatyga M, Sowa I, Wojciak M, Starobrat G, Danielewicz A. Complications in growth-friendly spinal surgeries for early-onset scoliosis: Literature review. World J Orthop. 2021 Aug 18;12(8):584-603. doi: 10.5312/wjo.v12.i8.584. eCollection 2021 Aug 18. PMID 34485105
• Ahmad AA. Early onset scoliosis and current treatment methods. J Clin Orthop Trauma. 2020 Mar-Apr;11(2):184-190. doi: 10.1016/j.jcot.2019.12.011. Epub 2019 Dec 24. PMID 32099277
• Helenius IJ, Oksanen HM, McClung A, Pawelek JB, Yazici M, Sponseller PD, Emans JB, Sanchez Perez-Grueso FJ, Thompson GH, Johnston C, Shah SA, Akbarnia BA. Outcomes of growing rod surgery for severe compared with moderate early-onset scoliosis: a matched comparative study. Bone Joint J. 2018 Jun 1;100-B(6):772-779. doi: 10.1302/0301-620X.100B6.BJJ-2017-1490.R1. PMID 29855249
• Hatem A, Elmorshidy EM, Elkot A, Hassan KM, El-Sharkawi M. Autofusion in growing rod surgery for early onset scoliosis; what do we know so far? SICOT J. 2024;10:15. doi: 10.1051/sicotj/2024011. Epub 2024 Apr 30. PMID 38687150
• Andras LM, Joiner ER, McCarthy RE, McCullough L, Luhmann SJ, Sponseller PD, Emans JB, Barrett KK, Skaggs DL; Growing Spine Study Group. Growing Rods Versus Shilla Growth Guidance: Better Cobb Angle Correction and T1-S1 Length Increase But More Surgeries. Spine Deform. 2015 May;3(3):246-252. doi: 10.1016/j.jspd.2014.11.005. Epub 2015 Apr 23. PMID 27927466
• Wilkinson JT, Songy CE, Bumpass DB, McCullough FL, McCarthy RE. Curve Modulation and Apex Migration Using Shilla Growth Guidance Rods for Early-onset Scoliosis at 5-Year Follow-up. J Pediatr Orthop. 2019 Sep;39(8):400-405. doi: 10.1097/BPO.0000000000000983. PMID 31393297

Identifiers

NCT: NCT07429656 · APC for EOS

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗