Case SeriesSelective Thoracic Fusion for Adolescent Idiopathic Scoliosis: Long-Term Radiographic and Functional Outcomes*
Introduction
The surgical treatment of adolescent idiopathic scoliosis (AIS) is aimed at curve correction, prevention of progression, and achieving a solid arthrodesis while maintaining coronal and sagittal balance. The curve classification system of King et al. brought recognition of the false double major curve (King 2), whereby the role of fusion of only the thoracic curve with a selective thoracic fusion (STF) was introduced [1]. This principle was further discussed by Lenke in the new classification system of Lenke 1B and 1C curve patterns [2].
Spontaneous lumbar curve correction has been observed with an STF, and short-term results have shown curve correction maintenance [3], [4], [5], [6], [7], with long-term studies including STF cases in the review of the outcome of fusion for AIS [8], [9]. There are three long-term studies of STF cases with a span of 7–20 years that report good outcomes [3], [10], [11].
This study was undertaken to investigate the long-term results of STF to answer the following three questions.
- 1.
Is the curve correction in the thoracic and balancing lumbar curves maintained?
- 2.
How do the patients function at follow-up in regard to health-related quality of life (HRQOL) measures?
- 3.
What are the radiographic changes in the lumbar curve below the fusion?
Section snippets
Materials and Methods
After IRB approval, the database at the center was queried and 152 patients were identified fulfilling the following criteria:
- 1.
Idiopathic scoliosis with surgery as an adolescent,
- 2.
Curve classified as King 2, 3, or 5 (Lenke 1 or 2),
- 3.
Selective thoracic fusion to L1 or above,
- 4.
Minimum of 20 years since surgery (surgery prior to January 1, 1994).
One hundred seventy-five patients were identified as having King 2 or 3 curves and 18 had incomplete or missing records and were eliminated. Of the remaining 157
Results
There were 35 cases of AIS and 5 of juvenile idiopathic scoliosis (JIS), the latter 5 having surgery as adolescents. The average age at presentation was 13.1 years (8.8–18.9). The average age at surgery was 14.5 years (11.7–18.9), with 37 having a posterior spine fusion and 3 a combined anterior and posterior fusion. The implants used were a Harrington distraction rod (12), Harrington distraction and compression rod (8), Harrington rod and sublaminar wires (8), and an all-hook construct (ie,
Discussion
There is still controversy whether King II, Lenke 1, are effectively treated with an STF, with maintenance of the lumbar curve balancing over time. Spontaneous correction has been shown in the literature. Edwards et al. [4] reported on 44 STF cases with a 2- to 16-year (mean 5-year) follow-up showing spontaneous lumbar correction, and from the same institution Chang et al. [3] reported on longer follow-ups of 5–24 years (mean 6.8 years) in 32 patients. Eighteen were considered successful with
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Comparison of differences and random errors in pedicle diameter measurements between MRI and CT: observational study of 315 pedicles in Lenke type 1 adolescent idiopathic scoliosis patients
2022, Spine JournalCitation Excerpt :However, radiation exposure from intraoperative CT imaging remains a concern [12]. In PS insertion for AIS, it is necessary to determine pedicle diameter as accurately as possible before surgery to maintain proper screw density [13–16], avoid unnecessary insertions, and determine the optimal fusion area [17]. We currently examine pedicle diameter by preoperative CT for careful insertion planning [18,19].
Defining “successful” treatment outcomes in adolescent idiopathic scoliosis: a scoping review
2023, European Spine Journal
Author disclosure: JEL (other from Zimmer/Biomet Spine, outside the submitted work).
IRB Approval: The study was approved through the University of Minnesota Institutional Review Board on April 4, 2014. The study number and title that were approved are IRB 1401M47263: “Long Term Outcome (20 Years +) of Selective Fusions for Adolescent Idiopathic Scoliosis.”