ICEOS 2016 Pelvic obliquity correction in distraction based

ICEOS 2016 Pelvic obliquity correction in distraction based growing spine constructs Mathew Schur BA 1, Lindsay M Andras MD 1, Paul D Sponseller MD MBA 2, John B Emans MD 3, David L Skaggs MD MMM 1, Growing Spine Study Group 1. Children's Orthopaedic Center, Children's Hospital Los Angeles; 2. Department of Orthopaedic Surgery, Johns Hopkins Childrens Hospital, Johns Hopkins University; 3. Department of Orthopaedic Surgery, Boston Children’s Hospital, Harvard Medical School • 1

Disclosures • • • a. b. c. d. e. f. Grants/Research Support Consultant Stock/Shareholder Speakers’ Bureau Other Financial Support Board/Committee member Mathew Schur, BA – None Lindsay M. Andras MD – Eli Lilly (c); Orthobullets (e) ; POSNA (f); SRS (f) Paul D. Sponseller MD, MBA – SRS (f); De. Puy (a&e); Globus Medical (e); JBJS (f); Oakstone Medical (e) John B. Emans MD – JCO (f); Medtronic Sofamor Danek (b); Synthes (b) David L. Skaggs MD MMM – SRS & POSNA (a); Biomet (e); Grand Rounds (b); Zipline Medical, Inc. (b & c); Medtronic (e); Johnson & Johnson (d); Wolters Kluwer Health - Lippincott Williams & Wilkins; Biomet Spine (e); Growing Spine Foundation (f); GSSG (f); JCO (f); Orthobullets (b), Spine Deformity (f) • 2

Background • The use of pelvic fixation in growing spine constructs allows for correction of the significant pelvic obliquity that can occur in patients with early-onset scoliosis (EOS) • Multiple options exist to provide this fixation • 3

Objective To determine if there is a difference in the correction of pelvic obliquity by different types of pelvic fixation Iliac screws Sacral Alar Iliac Screws S Hooks • 4

Methods • Neuromuscular, syndromic, and congenital EOS patients treated with bilateral distraction based implants with pelvic fixation from 1990 to 2013 were reviewed from a multicenter database. • Patients were divided into groups by type of pelvic fixation • Patients with less than 2 year follow-up or index instrumentation at ≥ 10 years of age were excluded • Statistical significance analyzed via t-test • 5

Results 34 patients met the inclusion criteria: • • Iliac screws - 14 patients Sacral-alar-iliac (SAI) screws – 6 patients S hook fixation – 6 patients S 1 screws alone – 8 patients • 6

Results Mean • • • preoperative radiographic measurements Cobb angle = 83 degrees T 1 -S 1 length = 250 mm Pelvic obliquity = 16. 6 degrees Mean • • • radiographic measurements at final follow-up Cobb angle = 49 degrees T 1 -S 1 length = 320 mm Pelvic obliquity = 7. 5 degrees • 7

Results Iliac screws 14 Preoperative pelvic obliquity (degrees) 20. 6 ± 11. 6 S 1 screws alone 8 SAI (± S 1) screws S hook iliac fixation Type of pelvic fixation Number of patients Postoperative Percent pelvic obliquity correction (degrees) (%) 9. 4 ± 6. 7 54 15. 3 ± 9. 0 6. 5 ± 6. 1 57 6 13. 9 ± 18. 3 3. 0 ± 2. 2 79 6 11. 7 ± 7. 3 8. 9 ± 4. 6 24 • 8

Discussion • Overall, iliac screw, SAI screw, and S 1 screw pelvic fixation achieved better correction of pelvic obliquity than S hooks • No difference was found in the correction of Cobb angle or T 1 -S 1 length • 9

Conclusion In dual rod distraction based implants, pelvic fixation with screws achieved better correction of pelvic obliquity than S hooks • 10

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