- Email: [email protected]
Paper #35 Ventral Rod Migration of Posteriorly Applied Growing Rod Technology for Early Onset Scoliosis
462
Abstracts / Spine Deformity 4 (2016) 446e464
Paper #33 CT Morphometric Analysis of Central Airways in Patients with Right Thoracic Scoliosis and Abnormal Sagittal Profile Enrique Garrido, James Farrell, Prashant Valluri Summary: This retrospective study compared the airway morphology of normal patients with patients with juvenile and adolescent onset idiopathic scoliosis and abnormal sagittal profile. Hypothesis: Lordoscoliosis causes right sided narrowing of bronchus intermedius and its bifurcation. Design: Case controlled retrospective imaging study. Introduction: Obstructive lung disease is prevalent in 39 % of patients with idiopathic scoliosis. We examine the morphology of central airways and its relationship to the spine as a possible causative factor. Methods: 7 patients with a main right thoracic scoliosis with hypokyphosis of !10 &[deg] (Group 1); 7 patients with kyphoscoliosis O40& [deg] (Group 2); and 7 age and sex matched patients without scoliosis (Group 3) were compared. Mean Cobb angle was 75&[deg]. Imaging software was used to segment the relevant anatomy. Airways and spine were normalised and referenced to the first thoracic vertebra. Cobb angles, anterior and lateral displacements of vertebra T6 & T7, spinal penetration index, airway volumes and cross-sections were measured. Results: ANOVA analysis demonstrated a statistically significant reduction (p!0.01) in Bronchus intermedius (BI) airway volumes and cross-sectional area when comparing Group 1 with Groups 2 & 3. The right bronchus intermedius bifurcated at T6 in Group 3 and at T7 in patients with scoliosis. In the frontal plain, the right main bronchus & bronchus intermedius had a more horizontal trajectory with increasing Cobb angle (p!0.05). Cross sectional narrowing and volume loss of the bronchus intermedius correlated positively with the degree of thoracic kyphosis (r 0.6), airway distance to spine (r 0.79) and negatively with the degree of scoliosis (r -0.57) and spinal penetration index (r -0.68). Predictive variables including Cobb angle, kyphosis angle, were included to produce a multivariate linear regression to estimate the normalised right bronchus intermedius volume: v 5 0.7132 0.0016 x &[theta]scol + 0.0025 x &[theta]kyph. Conclusions: Scoliosis alters the position and shape of the central airways. In patients with severe scoliosis and hypokyphosis airway volumes and cross section are significantly reduced in the BI and its bifurcation. Airway obstruction is less likely to be implicated in the loss of lung capacity in patients with kyphoscoliosis.
to treat Chiari malformations 2) determine if neurological decompression effects the progression of EOS. Hypothesis: Chiari malformations can be associated with scoliosis progression and prompt surgical decompression may alter the course of EOS progression preventing or delaying the need for future spinal surgeries. Design: Retrospective Case Series. Introduction: Chari Malformations are known to be associated with scoliosis diagnosed at a young age. It is unclear if surgical decompression of Chiari malformations influences the natural history of EOS. Previous case series on this topic have been small and have not focused on decompression as a potential treatment for EOS. The purpose of this study was to describe EOS progression in patients who have prompt decompression of their Chiari malformations. Methods: Patients !10 years of age diagnosed with scoliosis and Chiari malformations that required surgical decompression over the past 20 years were identified using electronic medical records. Demographic data, preand post operative radiographic data were collected. Patients with congenital, syndromic or concomitant causes of neuromuscular curves were excluded. The major curves of each patient were measured before decompression and at last follow-up. Patients who required further scoliosis treatment or surgery were recorded. Results: 42 patients including 29 females and 13 males with average age or 6.5 (2-9) years at presentation were included. The average age for neurosurgical decompression was 7 years (6 months after diagnosis). 21 (50%) patients were prescribed a scoliosis brace after their neurosurgical procedure. The mean cobb at presentation was 27 degrees and was 30 degrees at a mean follow was 5 years. Following decompression 12 (29%) patients experienced long-term improvement in their curves (O10 degrees), 19 (45%) experienced an insignificant change (!10 degrees), 11 (26%) patients had a significant decline in their curves (O10 degrees). Kyphosis and initial curve size were not predictive of curve progression or improvement. 5 patients in the study required spinal procedures (4 fusions and 1 growing rod followed by fusion). Conclusions: Overall, 74% of patients with EOS and a Chiari malformation had no significant progression of their Cobb angles after surgical treatment of the Chiari. Author disclosures: Eric Davis: None. Michael Glotzbecker: Depuy; Medtronic; Member of GSSG, CSSG, and HSG. Michael Troy: None. Lawrence Karlin: None. John Emans: Depuy Synthes; Medtronic; Journal of Children’s Orthopedics. M Timothy Hresko: None. Daniel Hedequist: None.
Paper #35 Ventral Rod Migration of Posteriorly Applied Growing Rod Technology for Early Onset Scoliosis Patrick Kiely, Laura-Ann Lambert
Author disclosures: Enrique Garrido: None. James Farrell: K2M. Prashant Valluri: Research Grant. Paper #34 Risk of Curve Progression in EOS after Surgical Decompression of Chiari Malformation Eric Davis, Michael Glotzbecker, Michael Troy, Lawrence Karlin, John Emans, M Timothy Hresko, Daniel Hedequist Summary: The purpose of this study was to retrospectively 1) describe the natural history of EOS patients who undergo neurological decompression
Summary: As growing rod technology evolves, we discover complications of it’s use previously undescribed. Ventral rod migration(VRM) is a potentially catastrophic complication of growing rods. We defined VRM as ventral movement O2 mm at the kyphotic apex, plotted from the posterior dorsal cortex of the apical lamina on axial CT. A review of CTimaging was conducted to assess for unidentified evidence of VRM. VRM was demonstrated in 3 patients, 1 of whom demonstrated rods positioned within the spinal canal. Hypothesis: Where advanced imaging such as computed tomography is available in posteriorly applied growing rods, it should be examined for evidence of ventral rod migration(VRM). Design: Retrospective observational cohort study. Introduction: Growing rod technology has a known high incidence of complications. However, we describe the identification of a rare complication, in an asymptomatic patient with early onset scoliosis treated using modern growing rod technology. This patient experienced ventral rod migration of a single rod (in her dual growing rod construct) 2 years after her index surgery. Post- operative CT imaging demonstrated the rod resided within the thoracic portion of her spinal canal. Methods: A retrospective review of all radiographic imaging was conducted for the growing rod cohort within a tertiary paediatric Orthopaedic
Abstracts / Spine Deformity 4 (2016) 446e464 Spinal Centre in Ireland. Between 2007-2015, 90 patients were treated with contemporary growing rod systems. We defined VRM as ventral movement O2 mm at the kyphotic apex, plotted from the posterior dorsal cortex of the apical lamina on axial CT. In patients identified as having objective evidence on imaging of VRM, we examined patient characteristics and tried to identify factors potentially contributing to the development of this complication. Results: 90 patients were treated with growing rods for early onset scoliosis between 2007 and 2015. Mean age at initial implantation was 8.62 years; mean follow-up was 36 months. CT imaging was available for 30 patients. There was evidence of VRM in 3 patients. In 1 patient, the rod a had breached the apical lamina and resided within the spinal canal. The mal-positioning of this rod is considered a significant factor in a deleterious routine rod lengthening procedure that culminated with a complete cord injury for the patient. Conclusions: Ventral rod migration is a potentially catastrophic complication of posteriorly applied growing rods. The use of advanced imaging in patients with posteriorly applied growing rods to screen for rare complications is a controversial area. VRM is a potentially quiescent complication and one we believe should be screened for in osteoporotic and severely kyphotic patients.
463
decreased incidence of SSIs. In a multivariate logistic regression model controlling for significant confounders, IUTs exceeding 100 minutes were associated with 8.5 times the odds of developing a SSI. Hypothesis: Reductions in preoperative IUT via a QPI are associated with reduced incidence of SSIs following VEPTR implantation. Design: A retrospective review of prospectively collected data. Introduction: Increased IUT, often equivalent to the anesthesia ready time (ART), has been associated with a greater risk of SSIs following adult spine surgery. The relationship between IUT, ART, and other variables remains unexplored in VEPTR implantation which often requires prolonged ART for line placement. The purpose of this study was to examine the effect of a QPI to minimize IUT and the impact on postoperative SSIs. Methods: A consecutive series of 187 VEPTR implant procedures performed between February 2007 and September 2015 was identified, with QPI begun in August 2013. Patient demographics, hospital length of stay, underlying diagnoses, ART, IUT, and perioperative variables were collected via retrospective registry review. The primary outcome measure was the presence of postoperative culture proven SSIs based on CDC criteria. A Student’s t-test was performed to assess changes in IUT and ART following the QPI. Chi-squared and binary logistic regression analysis were used to identify significant risk factors for SSIs. Results: A total of 16 procedures (8.6%) resulted in SSIs. Patients’ mean IUT decreased from 120 to 42 minutes following the QPI (p!0.001) while the mean ART did not change significantly (p50.422). The post-QPI infection rate was 3.2%/procedure compared to the pre-QPI incidence of 11.3%. Number-needed-to-treat (NNT) to prevent 1 infection was 12.3. Age, syndromic diagnosis, and IUT were significantly associated with the development of SSIs via bivariate analysis. In a logistic regression model incorporating these variables, only IUT (OR51.01,95%CI51.00-1.02,p50.021) and syndromic diagnosis (OR53.25,95%CI51.07-9.86,p50.038) remained significantly predictive of SSIs. An IUT exceeding 100 minutes was associated with 8.5 times the odds of developing an SSI. Conclusions: IUT was an independent, modifiable risk factor for developing SSIs in VEPTR implantation. Decreasing IUTs by QPI may reduce the incidence of SSIs. Author disclosures: Diane Hartman: None. Robert Campbell: None. Nikita Lakomkin: None. John Flynn: Biomet; Wolters Kluwer Health - Lippincott Williams & Wilkins; AAOS; American Board of Orthopedic Surgery, Inc.; Orthopedics Today; Pediatric Orthopaedic Society of North America; Scoliosis Research Society. Michael Nance: None. Thane Blinman: None. Oscar H. Mayer: Bristol-Myers Squib, Santhera Pharma, Catabasis Pharma. Howard Pantich: Philips Respironics. Anthony Capraro: None. Jesse Taylor, Brian Hanna: None. Keith Baldwin: None. Patrick Cahill: AAOS; Journal of Bone and Joint Surgery - American; Pediatric Orthopaedic Society of North America; Scoliosis Research Society; Spine Deformity. Lloydine Jacobs.
Paper #37 Author disclosures: Patrick Kiely: AO Spine Masters; Medtronic; Eurospine. Laura-Ann Lambert: None. Paper #36 Limiting Pre-Incision Instrument Uncovered Time via Q ua l i t y P r ac t i c e In t e r v e n t i on De c re as e s VE P T R Implantation Surgical Site Infections Diane Hartman, Robert Campbell, Nikita Lakomkin, John Flynn, Michael Nance, Thane Blinman, Oscar H. Mayer, Howard Pantich, Anthony Capraro, Jesse Taylor, Brian Hanna, Keith Baldwin, Patrick Cahill, Lloydine Jacobs Summary: Increased preoperative instrument exposure has been hypothesized to contribute to a greater risk of postoperative surgical site infection (SSI) in spine surgery. As such, a quality practice intervention (QPI) was implemented to reduce the instruments uncovered time (IUT) for VEPTR implantation. Reductions in IUT were significantly associated with
‘‘Next Day’’ Exam Reduces Radiation Exposure in Cervical Spine Clearance at a Level 1 Pediatric Trauma Center: A Pilot Study Martin Herman, Jonathan Phillips Summary: While CT scans are the standard for evaluating C-spines in the trauma setting, CT subjects patients to a large amount of radiation exposure. During the changes in C-spine protocols, CT scan usage decreased with ‘‘next day’’ clinical examinations. Hypothesis: Our goal is to address these concerns by promoting a C-spine clearance algorithm with the main objective of identifying C-spine injuries while minimizing radiation exposure. Design: In October 2012, we revised our original C-spine protocol in order to improve the process used for C-spine clearance and imaging. This protocol was then further revised in 2014 with the goal of decreasing CT scans through repeat, ‘‘next day’’ physical exams and increasing the involvement of Spine Services to clear C-spines apart from the admitting Trauma team. A retrospective review of the trauma database was performed on patients evaluated
Abstracts / Spine Deformity 4 (2016) 446e464
Paper #33 CT Morphometric Analysis of Central Airways in Patients with Right Thoracic Scoliosis and Abnormal Sagittal Profile Enrique Garrido, James Farrell, Prashant Valluri Summary: This retrospective study compared the airway morphology of normal patients with patients with juvenile and adolescent onset idiopathic scoliosis and abnormal sagittal profile. Hypothesis: Lordoscoliosis causes right sided narrowing of bronchus intermedius and its bifurcation. Design: Case controlled retrospective imaging study. Introduction: Obstructive lung disease is prevalent in 39 % of patients with idiopathic scoliosis. We examine the morphology of central airways and its relationship to the spine as a possible causative factor. Methods: 7 patients with a main right thoracic scoliosis with hypokyphosis of !10 &[deg] (Group 1); 7 patients with kyphoscoliosis O40& [deg] (Group 2); and 7 age and sex matched patients without scoliosis (Group 3) were compared. Mean Cobb angle was 75&[deg]. Imaging software was used to segment the relevant anatomy. Airways and spine were normalised and referenced to the first thoracic vertebra. Cobb angles, anterior and lateral displacements of vertebra T6 & T7, spinal penetration index, airway volumes and cross-sections were measured. Results: ANOVA analysis demonstrated a statistically significant reduction (p!0.01) in Bronchus intermedius (BI) airway volumes and cross-sectional area when comparing Group 1 with Groups 2 & 3. The right bronchus intermedius bifurcated at T6 in Group 3 and at T7 in patients with scoliosis. In the frontal plain, the right main bronchus & bronchus intermedius had a more horizontal trajectory with increasing Cobb angle (p!0.05). Cross sectional narrowing and volume loss of the bronchus intermedius correlated positively with the degree of thoracic kyphosis (r 0.6), airway distance to spine (r 0.79) and negatively with the degree of scoliosis (r -0.57) and spinal penetration index (r -0.68). Predictive variables including Cobb angle, kyphosis angle, were included to produce a multivariate linear regression to estimate the normalised right bronchus intermedius volume: v 5 0.7132 0.0016 x &[theta]scol + 0.0025 x &[theta]kyph. Conclusions: Scoliosis alters the position and shape of the central airways. In patients with severe scoliosis and hypokyphosis airway volumes and cross section are significantly reduced in the BI and its bifurcation. Airway obstruction is less likely to be implicated in the loss of lung capacity in patients with kyphoscoliosis.
to treat Chiari malformations 2) determine if neurological decompression effects the progression of EOS. Hypothesis: Chiari malformations can be associated with scoliosis progression and prompt surgical decompression may alter the course of EOS progression preventing or delaying the need for future spinal surgeries. Design: Retrospective Case Series. Introduction: Chari Malformations are known to be associated with scoliosis diagnosed at a young age. It is unclear if surgical decompression of Chiari malformations influences the natural history of EOS. Previous case series on this topic have been small and have not focused on decompression as a potential treatment for EOS. The purpose of this study was to describe EOS progression in patients who have prompt decompression of their Chiari malformations. Methods: Patients !10 years of age diagnosed with scoliosis and Chiari malformations that required surgical decompression over the past 20 years were identified using electronic medical records. Demographic data, preand post operative radiographic data were collected. Patients with congenital, syndromic or concomitant causes of neuromuscular curves were excluded. The major curves of each patient were measured before decompression and at last follow-up. Patients who required further scoliosis treatment or surgery were recorded. Results: 42 patients including 29 females and 13 males with average age or 6.5 (2-9) years at presentation were included. The average age for neurosurgical decompression was 7 years (6 months after diagnosis). 21 (50%) patients were prescribed a scoliosis brace after their neurosurgical procedure. The mean cobb at presentation was 27 degrees and was 30 degrees at a mean follow was 5 years. Following decompression 12 (29%) patients experienced long-term improvement in their curves (O10 degrees), 19 (45%) experienced an insignificant change (!10 degrees), 11 (26%) patients had a significant decline in their curves (O10 degrees). Kyphosis and initial curve size were not predictive of curve progression or improvement. 5 patients in the study required spinal procedures (4 fusions and 1 growing rod followed by fusion). Conclusions: Overall, 74% of patients with EOS and a Chiari malformation had no significant progression of their Cobb angles after surgical treatment of the Chiari. Author disclosures: Eric Davis: None. Michael Glotzbecker: Depuy; Medtronic; Member of GSSG, CSSG, and HSG. Michael Troy: None. Lawrence Karlin: None. John Emans: Depuy Synthes; Medtronic; Journal of Children’s Orthopedics. M Timothy Hresko: None. Daniel Hedequist: None.
Paper #35 Ventral Rod Migration of Posteriorly Applied Growing Rod Technology for Early Onset Scoliosis Patrick Kiely, Laura-Ann Lambert
Author disclosures: Enrique Garrido: None. James Farrell: K2M. Prashant Valluri: Research Grant. Paper #34 Risk of Curve Progression in EOS after Surgical Decompression of Chiari Malformation Eric Davis, Michael Glotzbecker, Michael Troy, Lawrence Karlin, John Emans, M Timothy Hresko, Daniel Hedequist Summary: The purpose of this study was to retrospectively 1) describe the natural history of EOS patients who undergo neurological decompression
Summary: As growing rod technology evolves, we discover complications of it’s use previously undescribed. Ventral rod migration(VRM) is a potentially catastrophic complication of growing rods. We defined VRM as ventral movement O2 mm at the kyphotic apex, plotted from the posterior dorsal cortex of the apical lamina on axial CT. A review of CTimaging was conducted to assess for unidentified evidence of VRM. VRM was demonstrated in 3 patients, 1 of whom demonstrated rods positioned within the spinal canal. Hypothesis: Where advanced imaging such as computed tomography is available in posteriorly applied growing rods, it should be examined for evidence of ventral rod migration(VRM). Design: Retrospective observational cohort study. Introduction: Growing rod technology has a known high incidence of complications. However, we describe the identification of a rare complication, in an asymptomatic patient with early onset scoliosis treated using modern growing rod technology. This patient experienced ventral rod migration of a single rod (in her dual growing rod construct) 2 years after her index surgery. Post- operative CT imaging demonstrated the rod resided within the thoracic portion of her spinal canal. Methods: A retrospective review of all radiographic imaging was conducted for the growing rod cohort within a tertiary paediatric Orthopaedic
Abstracts / Spine Deformity 4 (2016) 446e464 Spinal Centre in Ireland. Between 2007-2015, 90 patients were treated with contemporary growing rod systems. We defined VRM as ventral movement O2 mm at the kyphotic apex, plotted from the posterior dorsal cortex of the apical lamina on axial CT. In patients identified as having objective evidence on imaging of VRM, we examined patient characteristics and tried to identify factors potentially contributing to the development of this complication. Results: 90 patients were treated with growing rods for early onset scoliosis between 2007 and 2015. Mean age at initial implantation was 8.62 years; mean follow-up was 36 months. CT imaging was available for 30 patients. There was evidence of VRM in 3 patients. In 1 patient, the rod a had breached the apical lamina and resided within the spinal canal. The mal-positioning of this rod is considered a significant factor in a deleterious routine rod lengthening procedure that culminated with a complete cord injury for the patient. Conclusions: Ventral rod migration is a potentially catastrophic complication of posteriorly applied growing rods. The use of advanced imaging in patients with posteriorly applied growing rods to screen for rare complications is a controversial area. VRM is a potentially quiescent complication and one we believe should be screened for in osteoporotic and severely kyphotic patients.
463
decreased incidence of SSIs. In a multivariate logistic regression model controlling for significant confounders, IUTs exceeding 100 minutes were associated with 8.5 times the odds of developing a SSI. Hypothesis: Reductions in preoperative IUT via a QPI are associated with reduced incidence of SSIs following VEPTR implantation. Design: A retrospective review of prospectively collected data. Introduction: Increased IUT, often equivalent to the anesthesia ready time (ART), has been associated with a greater risk of SSIs following adult spine surgery. The relationship between IUT, ART, and other variables remains unexplored in VEPTR implantation which often requires prolonged ART for line placement. The purpose of this study was to examine the effect of a QPI to minimize IUT and the impact on postoperative SSIs. Methods: A consecutive series of 187 VEPTR implant procedures performed between February 2007 and September 2015 was identified, with QPI begun in August 2013. Patient demographics, hospital length of stay, underlying diagnoses, ART, IUT, and perioperative variables were collected via retrospective registry review. The primary outcome measure was the presence of postoperative culture proven SSIs based on CDC criteria. A Student’s t-test was performed to assess changes in IUT and ART following the QPI. Chi-squared and binary logistic regression analysis were used to identify significant risk factors for SSIs. Results: A total of 16 procedures (8.6%) resulted in SSIs. Patients’ mean IUT decreased from 120 to 42 minutes following the QPI (p!0.001) while the mean ART did not change significantly (p50.422). The post-QPI infection rate was 3.2%/procedure compared to the pre-QPI incidence of 11.3%. Number-needed-to-treat (NNT) to prevent 1 infection was 12.3. Age, syndromic diagnosis, and IUT were significantly associated with the development of SSIs via bivariate analysis. In a logistic regression model incorporating these variables, only IUT (OR51.01,95%CI51.00-1.02,p50.021) and syndromic diagnosis (OR53.25,95%CI51.07-9.86,p50.038) remained significantly predictive of SSIs. An IUT exceeding 100 minutes was associated with 8.5 times the odds of developing an SSI. Conclusions: IUT was an independent, modifiable risk factor for developing SSIs in VEPTR implantation. Decreasing IUTs by QPI may reduce the incidence of SSIs. Author disclosures: Diane Hartman: None. Robert Campbell: None. Nikita Lakomkin: None. John Flynn: Biomet; Wolters Kluwer Health - Lippincott Williams & Wilkins; AAOS; American Board of Orthopedic Surgery, Inc.; Orthopedics Today; Pediatric Orthopaedic Society of North America; Scoliosis Research Society. Michael Nance: None. Thane Blinman: None. Oscar H. Mayer: Bristol-Myers Squib, Santhera Pharma, Catabasis Pharma. Howard Pantich: Philips Respironics. Anthony Capraro: None. Jesse Taylor, Brian Hanna: None. Keith Baldwin: None. Patrick Cahill: AAOS; Journal of Bone and Joint Surgery - American; Pediatric Orthopaedic Society of North America; Scoliosis Research Society; Spine Deformity. Lloydine Jacobs.
Paper #37 Author disclosures: Patrick Kiely: AO Spine Masters; Medtronic; Eurospine. Laura-Ann Lambert: None. Paper #36 Limiting Pre-Incision Instrument Uncovered Time via Q ua l i t y P r ac t i c e In t e r v e n t i on De c re as e s VE P T R Implantation Surgical Site Infections Diane Hartman, Robert Campbell, Nikita Lakomkin, John Flynn, Michael Nance, Thane Blinman, Oscar H. Mayer, Howard Pantich, Anthony Capraro, Jesse Taylor, Brian Hanna, Keith Baldwin, Patrick Cahill, Lloydine Jacobs Summary: Increased preoperative instrument exposure has been hypothesized to contribute to a greater risk of postoperative surgical site infection (SSI) in spine surgery. As such, a quality practice intervention (QPI) was implemented to reduce the instruments uncovered time (IUT) for VEPTR implantation. Reductions in IUT were significantly associated with
‘‘Next Day’’ Exam Reduces Radiation Exposure in Cervical Spine Clearance at a Level 1 Pediatric Trauma Center: A Pilot Study Martin Herman, Jonathan Phillips Summary: While CT scans are the standard for evaluating C-spines in the trauma setting, CT subjects patients to a large amount of radiation exposure. During the changes in C-spine protocols, CT scan usage decreased with ‘‘next day’’ clinical examinations. Hypothesis: Our goal is to address these concerns by promoting a C-spine clearance algorithm with the main objective of identifying C-spine injuries while minimizing radiation exposure. Design: In October 2012, we revised our original C-spine protocol in order to improve the process used for C-spine clearance and imaging. This protocol was then further revised in 2014 with the goal of decreasing CT scans through repeat, ‘‘next day’’ physical exams and increasing the involvement of Spine Services to clear C-spines apart from the admitting Trauma team. A retrospective review of the trauma database was performed on patients evaluated