7Th International Congress on Early Onset Scoliosis and Growing Spine (ICEOS)

7th International Congress on Early Onset Scoliosis and Growing Spine (ICEOS)

November 21-22, 2013

Rancho Bernardo, CA

FREE PAPERS

Disclosure Key:

A.  Grants/Research Support

B.  Consulting Fees

C.  Speakers’ Bureau

D.  Ownership Interest/Shareholder

E.  Salary

F.  Royalty /Patent Holder

Free Paper #16: Early Onset Scoliosis Treated With Growing Rods Has More Spinal Growth, Better Cobb Correction, But More Than Twice The Number Of Surgeries Compared To Shilla

Lindsay M. Andras, MD; Elizabeth R.A. Joiner, BS; Richard E. McCarthy, MD; Scott J. Luhmann, MD; Paul D. Sponseller, MD; John B. Emans, MD; David Skaggs, MD, MMM; Growing Spine Study Group

Introduction: The purpose of this study is to compare treatment of early onset scoliosis (EOS) with Shilla versus dual growing rods.

Methods: A multi-center case-matched comparison of patients with early
onset scoliosis treated with Shilla vs. dual spine-spine growing rods (GR) from 1995-2009 was performed. Radiographic outcomes and complications were recorded. 37 Shilla patients from 3 centers were matched with 37 GR patients from a multi-center database by age at index surgery (±1 year), preoperative Cobb angle (±15°), and diagnosis (neuromuscular, congenital, idiopathic, syndromic). Average follow up did not differ significantly between groups (GR=4.3yrs, Shilla=4.6 yrs; p=0.353).
Results: Comparing pre-operative to latest follow-up (mean > 4yrs) improvement in average Cobb angle was 36° (72° to 36°) in the GR group versus 24° (69° to 45°) in the Shilla group (p=0.014). T1-S1 length increased 8.7cm in patients treated with GR compared to 6.4cm in Shilla patients (p=0.013). The Shilla patients had significantly fewer surgeries (2.8) than the GR group (7.4) (p<0.001) but had a higher rate of unplanned surgeries for implant complications (Shilla = 1.3, GR = 0.4; p = 0.008). When revisions for implant complications done at the time of scheduled lengthenings and revisions for construct maintenance were included, the two groups did not differ significantly in number of procedures for implant complications (Shilla=1.5, GR=1.4, p = 0.888). The overall complication rate did not differ significantly between groups (Shilla = 1.9 (range, 0-7), GR = 1.2 (range, 0-9); p = 0.142).

Conclusions: The GR group had a significantly greater improvement in Cobb angle and a greater increase in T1-S1 length than Shilla. GR patients had more surgeries, but Shilla patients had more unplanned procedures. The rate of complications overall did not differ significantly between the two groups.

Disclosures: L.M. Andras: None. E.R. Joiner: None. R.E. McCarthy: B; Medtronic. C; Medtronic. F; Medtronic. S.J. Luhmann: A; Medtronic Sofamor Danek. B; Medtronic Sofamor Danek, Watermark Research. C; Medtronic Sofamor Danek, Stryker. F; Globus Medical. P.D. Sponseller: A; DePuy, A Johnson & Johnson Company. B; DePuy, A Johnson & Johnson Company. F; Globus Medical, DePuy, A Johnson & Johnson Company, Journal of Bone and Joint Surgery oakstone medical. J.B. Emans: B; Synthes, Medtronic Sofamor Danek. F; Synthes. D. Skaggs: A; Institutional support from Medtronic, POSNA and SRS; both paid to Columbia University. B; Biomet; Medtronic; BeachBody LLC. C; Biomet; Medtronic; Stryker. F; Biomet; Medtronic/Biomet (osteotome). G. Study Group: None.

Free Paper #17: Five to Sixteen-Year Results of 201 Growing Rod Patients: Is There a Difference Between Etiologies?

Behrooz A. Akbarnia, MD; Nima Kabirian, MD; Jeff Pawelek, BS; George H. Thompson, MD; John B. Emans, MD; Paul D. Sponseller, MD, MBA; David L. Skaggs, MD; Growing Spine Study Group

Introduction: Etiology was identified as a core component for a new classification system of Early Onset Scoliosis (C-EOS). The purpose of this study was to compare long-term results of GR treatment between etiologies in a large cohort of patients.

Methods: Out of 574 GR patients from a multicenter database, 201 patients had minimum 5-year follow-up (F/U) and data available for analysis. Based on C-EOS, patients were grouped into four etiologies: Congenital/Structural (C), Neuromuscular (N), Syndromic (S) and Idiopathic (I). Annual T1-S1 growth is the T1-S1 increase from post-index GR surgery to the latest F/U divided by the length of time from post-index GR surgery to the latest F/U. Latest F/U was the most recent visit prior to final fusion.

Results: There were 47 (24%) “C” patients, 49 (24%) “N” patients, 62 (31%) “S” patients and 43 (21%) “I” patients. “C” patients had the least curve correction at index GR surgery and the greatest loss of curve correction from post-index surgery to latest F/U. Only “I” patients preserved their curve correction from post-index GR to latest F/U. Annual T1-S1 growth was not statistically different across all etiologies (P=0.628). “N” patients had the largest T1-S1 increase at index but the lowest annual T1-S1 growth. “C” patients had the smallest T1-S1 increase at index surgery. “S” patients had the highest annual T1-S1 growth after index GR surgery. (Table 1)

Conclusion: Across all etiologies, the majority of curve correction was achieved at the index GR surgery. “I” patients maintained their curve correction during the treatment period but non-“I” patients lost up to 30% of their curve correction from post-index GR surgery to latest F/U. Annual T1-S1 growth was comparable across all etiologies.

Disclosures: B.A. Akbarnia: A; DePuy, Nuvasive. B; Nuvasive, K2M, Ellipse, K Spine. D; Nuvasive, Ellipse, K Spine, Nocimed. F; DePuy, Nuvasive. N. Kabirian: None. J. Pawelek: None. G.H. Thompson: E; Innovative Interventions, LLC. F; Lippincott. J.B. Emans: B; Medtronic, Synthes. F; Synthes. P.D. Sponseller: A; DePuy. B; DePuy. F; Globus Medical, DePuy, Journal of Bone & Joint Surgery. D.L. Skaggs: B; Medtronic, Biomet. C; Medtronic, Stryker, Biomet. F; Biomet, Medtronic. G. Study Group: A; Growing Spine Foundation.

Free Paper #18: Traditional Growing Rods Versus Magnetically Controlled Growing Rods in Early Onset Scoliosis: A Case-Matched Two-Year Study

Behrooz A. Akbarnia, MD; Kenneth Cheung, MD; Gokhan Demirkiran, MD; Hazem Elsebaie, FRCS, MD; John B. Emans, MD; Charles E. Johnston, MD; Gregory M. Mundis, MD; Hilali Noordeen, FRCS; Jeff Pawelek; Matthew Shaw, FRCS; David L. Skaggs, MD, MMM; Paul D. Sponseller, MD, MBA; George H. Thompson, MD; Muharrem Yazici, MD; Growing Spine Study Group

Introduction: Recent studies have shown repeated traditional growing rod (TGR) lengthenings increase the risk of complications in early onset scoliosis. Magnetically controlled growing rods (MCGR) are available outside the U.S. and early results have been promising. The purpose of this study was to compare 2-year outcomes of MCGR and TGR using a case-matched series.

Methods: MCGR patients were selected based on the following criteria: 30º, T1-T12 <22 cm, no previous spine surgery and minimum 2-year follow-up. 12 of the 17 qualified MCGR patients had complete data available for analysis. Each MCGR patient was matched to a TGR patient by etiology, gender, single vs. dual rods, pre-op age (+/-10 months) and pre-op major curve (+/-20º). One male MCGR patient was matched to a female TGR patient since a male-male match could not be found. Annual T1-S1 growth was the change in spinal height from post-index surgery to latest follow-up divided by the time interval.
Results: There were 4 neuromuscular, 4 syndromic, 3 idiopathic and 1 congenital patient in each group. MCGR patients had a mean pre-op age of 6.8 years, which was similar to TGR patients. Mean post-op follow-up was greater for the TGR patients (4.1 vs. 2.5 years; p=0.01). Major curve correction was not significantly different between the groups at any time point (Table 1). TGR patients had significantly greater overall gain in T1-S1 compared to MCGR patients (p=0.01). Annual T1-S1 growth was greater for TGR patients (11 vs. 7 mm/year) but this difference did not reach statistical significance. MCGR patients had 16 open surgeries and 137 non-invasive lengthenings while the TGR cohort had 78 open surgeries including 49 surgical lengthenings. 2/12 MCGR patients had 4 revisions, and 8/12 TGR patients had 17 revisions (p=0.05). There were 14 complications in MCGR patients and 23 in TGR patients.

Conclusions: There was no significant difference in major curve correction between groups. TGR patients had a greater overall increase in spinal height; however, annual T1-S1 growth was not significantly different between the two groups. MCGR patients had 62 fewer open surgical procedures than TGR patients, and TGR patients experienced a significantly higher rate of revision surgery.

Disclosures: B.A. Akbarnia: A; Depuy-Synthes, Nuvasive. B; Nuvasive, K2M, Ellipse, K Spine. D; Nuvasive, Ellipse, K Spine, Nocimed. F; Depuy-Synthes, Nuvasive. K. Cheung: A; Ellipse Technologies. B; Ellipse Technologies. G. Demirkiran: None. H. Elsebaie: B; K Spine, Ellipse Technologies. J.B. Emans: B; Depuy-Synthes, Medtronic. F; Depuy-Synthes. C.E. Johnston: F; Medtronic, Saunders/Mosby-Elsevier. G.M. Mundis: A; Nuvasive, Depuy-Synthes, OREF. B; Nuvasive, K2M. C; Nuvasive, K2M. F; Nuvasive, K2M. H. Noordeen: B; Baxter, K2M, Ellipse Technologies, K Spine. C; K2M, Ellipse Technologies, K Spine. J. Pawelek: None. M. Shaw: None. D.L. Skaggs: B; Biomet, Medtronic. C; Biomet, Medtronic, Stryker. F; Biomet, Medtronic. P.D. Sponseller: A; Depuy-Synthes. B; Depuy-Synthes. F; Globus Medical, Depuy-Synthes, Journal of Bone and Joint Surgery, Oakstone Medical. G.H. Thompson: E; Innovative Interventions,LLC. F; Lippincott. M. Yazici: C; Ellipse Technologies, Depuy-Synthes. G. Study Group: A; Growing Spine Foundation.

Free Paper #19: CT Lung Volume Changes after Surgical treatment for Early-onset Scoliosis

Charles E. Johnston, MD; Anna McClung, BSN, RN

Introduction: Treatment of EOS must focus on gains in thoracic/lung volume as much as deformity management, in order to minimize thoracic insufficiency risk. In patients unable to perform standard PFTs, CT volume determination (CTvol) is an important objective anatomic measure of treatment effect on the thorax.

Methods: 20 patients had preoperative and postoperative CT lung volumes performed mean 2.7 yr later. 12 had non-congenital curves, 8 congenital. 11 patients had spine-based treatment (SB), 9 rib-based (RB). CTvol's were correlated to thoracic xray dimensions (T1-12 length, T6 coronal width, pelvic width) and curve magnitude.

Results: CT lung volume increased in all patients from mean 724cc preop (range 201-1267) to 1072cc (456-2021) at f/u. RB cases gained 51%, vs. 46% in SB (not signif). RB cases had smaller preop volume than SB (522 vs 889cc, p<.01)) due to most being congenital and scans performed at younger age. Preoperative T1-T12 as normalized by pelvic width was below the 5th percentile in all patients; at postoperative follow-up 40% had increased above the 5th percentile (5% -60%). T1-12 length also increased with rx (115mm → 141 @ f/u for RB, 139 → 165 for SB) and correlated with CTvol preop r=.64, p=.002 and postop r=.58, p=.006. Pre-treatment coronal T6 width showed the greatest difference between RB and SB cases (p=.001), and this was maintained at f/u (p=.004). T6 width correlated best with CTvol r=.76 p<.0001preop and .82 p<.0001 postop, and less well with Δvol pre-to-post r=.54, p=.01. Pelvic width and CTvol correlated well (r=.7, p<.001 pre & post). There was NO correlation between CTvol and MT Cobb, but weak correlation with %curve correction r=.47, p=.03.

Conclusions: CT objectively demonstrates improved lung volume related to EOS surgical treatment in all patients. Distraction-based constructs achieved ≈50% increases in CTvol regardless of whether the cases was congenital/ RB treatment or non-congenital/SB treatment. While all patients were below the 5th percentile, 40% made significant gains in thoracic height as normalized by pelvic width. Thoracic dimensions (T1-12 spine length, pelvic width, and especially T6 coronal width) appear to be reliable surrogate measures for CT volumes. Curve magnitude and correction correlate poorly with CTvol, thus assuming less importance in evaluating EOS outcome.

Disclosures: A. McClung: None. C.E. Johnston: A; SRS, OREF. F; Medtronic.

Free Paper #20: Peri-Operative Neurological Injury Associated with Rib-Distraction Surgery

Luke Gauthier, M.D.; Yousef Mandourah, B.Sc.; Amy McIntosh; Jack Flynn; Ron El-Hawary, MD, MSc, FRCSC

Introduction: General complication rates for posterior distraction-based surgery are known to be high; however, there are few reports in the literature on neurologic injury after rib-based distraction. Our purpose was to define the rates of neurologic injury associated with these surgeries as well as to determine if pre-operative diagnosis affects these rates.

Methods: This was a retrospective review of the CWSDSG database from 2004-2013. Chi-square testing was used to compare the distributions of proportions between diagnoses. Significance was defined as p<0.05*.

Results: There were 524 patients identified who were treated with rib-based distraction. Using the Classification for Early Onset Scoliosis, diagnoses was 223 congenital, 163 neuromuscular, 63 syndromic, 67 idiopathic, and 8 unknown. There were 9 neurologic injuries identified for a rate of 1.7%. Seven of these patients were classified as congenital and 2 as idiopathic, each with a neurologic injury rate of 3%*. At the time of injury, mean age was 4.1 years, mean scoliosis was 66.2° and mean kyphosis was 44.2°. All injuries occurred at the time of initial implantation, with the exception of one patient in which injury occurred during revision surgery. There were no injuries identified during routine lengthening surgery. None of these injuries were complete spinal cord injuries and the majority involved injury to the brachial plexus (n=5). Re-operation (devices shortened or partially removed) was required for 4 patients. At a mean follow-up of 4.2 years, 7 of 9 patients had full resolution of their symptoms and 2 of 9 patients had residual upper extremity weakness.

Conclusions: The rate of neurologic injury for patients treated with rib-based distraction surgery was 1.7%. These injuries were predominantly to the brachial plexus and generally resolved. Rates of neurologic injury were higher for patients with congenital/structural and for those with idiopathic diagnoses.

Disclosures: L. Gauthier: None. Y. Mandourah: None. A. McIntosh: B; Synthes. J. Flynn: F; Biomet. R. El-Hawary: A; Depuy-Synthes, Medtronic. B; Depuy-Synthes, Medtronic, Halifax Biomedical Inc..

Free Paper #21: The Classification for Early Onset Scoliosis (C-EOS) Identifies Patients at Higher Risk for Complications at 5 years of Follow Up

Michael G. Vitale, MD MPH; Howard Y. Park, BA; Hiroko Matsumoto, MA; Tricia St. Hilaire, BS; Jeff B. Pawelek, BS; Evan P. Trupia, BS; Hasani W. Swindell, BS; John M. Flynn, MD; David L. Skaggs, MD; David P. Roye, MD

Introduction: The Classification of Early Onset Scoliosis is a consensus-based classification system developed by leaders in EOS spine surgery to predict disease course and prognosticate outcomes. An initial validation study demonstrated that the C-EOS predicts time to anchor failure in VEPTR surgery. To further validate the prognostic potential of the C-EOS, this study aims to examine the frequency and severity of device-related complications among C-EOS classes following surgery.