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Paper #8 Normative Data of PFTs and Measures of Chest Development: Is a T1-T12 Height of 22 cm Adequate?
Abstracts / Spine Deformity 3 (2015) 612e629 Stephen J. Soufleris, BS, Ryan P. Murphy, BS, Jeffrey R. Sawyer, MD, Children’s Spine Study Group Introduction: A common treatment strategy for early onset scoliosis (EOS) patients is the use of rib or spine-based distraction followed by PSF at the end of growth. However, there are patients who do not undergo PSF at the end of distraction. The purpose of this study is to compare the outcomes of patients who undergo PSF compared to observation (OB) at the end of distraction. Methods: An IRB-approved review of the Children’s Spine Study Group (CSSG) registry was performed. Children with EOS who completed growth friendly treatment and who underwent OB or PSF at the end of distraction were included. Radiographic parameters at the beginning and end of distraction, post PSF (PSF group), and final follow up including coronal/sagittal curve, T1-T12 and T1-S1 height were measured. Operative complications as classified by Smith in the PSF group and the number of procedures after PSF or discontinuation of distraction were analyzed. Results: There were 37 patients identifed: 25 (67%) underwent PSF and 12 (33%) OB. The mean follow up is 15.6 and 16.2 years from initiation of distraction in the PSF and OB groups respectively. The most common cEOS curve in both was C3. The mean age of initiation of distraction was 4.2 years in both groups. The mean number of total procedures in the PSF and OB groups was 11.3 (3-21) and 8.7 (2-16) respectively. At the end of distraction the groups were similar in terms of coronal curve (59 PSF/51 OB), kyphosis (52 PSF/50 OB), T1-T12 height(20.4cm PSF/19.8cm OB) and T1-S1 height (32.8cm PSF/32.0cm OB). The mean age of the PSF group was 12.9 years. There was some intial correction in the PSF group (mean age 12.9 years) in terms of coronal curve (10 ), kyphosis (8 ), T1-T2 height (1.6cm) and T1-S1 height(2.5cm). Following PSF there were 23 complications in 13 patients (35%, range 1-4/pt) of which 11(48%) were device related (Type I:2, Type II:5, Type III: 4) and 12 (52%) were disease related (Type I:3, Type II:7, Type III: 2). There were no complications in the observation group. At final follow up there was slightly less scoliosis (55 vs 59 ), kyphosis (47 vs 56 ) and slightly greater spine height in the PSF group (T1-T12: 21.5 vs 19cm)(T1-S1: 35.3 vs 31.4cm). There were 4 additional procedures after PSF (1 repeat PSF, 2 implant removal, 1 revision) and 0 in the OB group. Conclusion: The decision to perform a PSF at the end of distraction is complicated and multifactorial. While PSF does provide some deformity correction and increased spine height it is associated with a high complication rate. Further studies are necessary to determine the optimal treatment for children with EOS who have completed distraction. Author disclosures: R.G. Mendonca: None. A. Samdani: B; Depuy, Globus Medical, Stryker, Zimmer. J.T. Smith: B; Biomet, Ellipse Technologies, Globus Medical, Spine Guard, Synthes. F; Synthes. J.B. Emans: B; Medtronic Sofamor Danek, Synthes. F; Synthes. T.A. St. Hilaire: None. T.S. Flynn: None. S.J. Soufleris: None. R.P. Murphy: None. J.R. Sawyer: F; Wolters Kluwer Health - Lippincott Williams & Wilkins, Mosby. C. Study Group: A; Depuy Synthes, Children’s Spine Foundation. Paper #8 Normative Data of PFTs and Measures of Chest Development: Is a T1-T12 Height of 22 cm Adequate? June C. Smith, MPH, Megan Kerstein, James Gregory, MD, Scott J. Luhmann Introduction: Shortening of the spine from T1-T12, such as with early spinal fusion for spinal deformity, has demonstrated to be deleterious to development of the pulmonary system, quantified by pulmonary function tests. It has been proposed that a T1-T12 distance of 22 cm at skeletal maturity is adequate for pulmonary function, based on patients’ symptoms. Methods: A hospital pulmonology database was queried to identify all patients who underwent pulmonary function testing (PFT). Inclusion criteria were pulmonary function values greater than 90%, which consisted
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mainly of patients with minimal to mild asthma. Patients were excluded if there was chest or spine deformity. This list was cross-referenced to Radiology database to identify all patients who had a chest radiograph, within 2 months of the PFT study. 1797 PFT studies were identified. After applying the inclusion and exclusion criteria, and eliminating duplicates, 149 patients remained for analysis. PFT data collected included absolute FVC, %-predicted FVC, absolute FEV1, and %-predicted FEV1. Radiographic measurements on the chest radiograph included T1-T12 height, Coronal Chest Width (CCW) and Space Available for the Lung (SAL) bilaterally. Results: There were 149 patients which satisfied the inclusion and exclusion criteria. Mean age was 12.4 years, and %-predicted FEV1 and FVC were 106.9% and 103.9%, respectively. Mean T1-T12 height was 25.6 cm, CCW 25.5 cm, SAL bilaterally was 19.0 cm. FEV1 and FVC values, and radiographic values of T1-T12 height, CCW and SAL are shown in Graphs 1 and 2. A sub-cohort of patients was created of patients with T1-T12 height of 22-24 cm, hence patients who should have adequate pulmonary development at maturity. 21 patients (11 female, 10 male) were identified (see Table 1). Absolute FEV1 and FVC were 1.97 l and 2.17 l, respectively. Spirometric standards for healthy adult lifetime nonsmokers, by Gore et al, were utilized to assess the impact of T1-T12 shortening on PFT values. By inputting the mean FEV1 and FVC values for the 22-24 cm T1-T12 height group, and mean height of females (163.41 cm) and males (168.7 cm) in our cohort the %-predicted PFT values were calculated. Calculating for 15 year old females the FEV1 and FVC %-predicted was 46% and 44%; for males FEV1 was 43% and FVC 42% predicted, respectively. Conclusion: T1-T12 height at skeletal maturity of 22 cm may not be enough to guarantee patients will have an asymptomatic pulmonary status. Though this analysis does not take into consideration radial expansion of the chest during maturity, the %-predicted FEV1 and FVC values are concerning, and deserve further analysis.
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Abstracts / Spine Deformity 3 (2015) 612e629
Author disclosures: J.C. Smith: None. M. Kerstein: None. J. Gregory: None. S.J. Luhmann: B; Medtronic, Stryker, Orthofix. C; Medtronic, Stryker. F; Globus Medical, Lippincott. Paper #9 Step Activity Monitoring to Assess Functional Outcome in EOS ‘‘Graduates’’ Charles E. Johnston, MD, Wilshaw Stevens, Jr, BS, Kelly A. Jeans, MS Introduction: EOS patients are suspected to have impaired pulmonary function in spite of treatment. The clinical success of maximizing lung capacity using growth-friendly constructs before spinal fusion is somewhat unproven due to outcome measures of limited correlation to actual function. Understanding a patient’s ability to participate with peers and daily function is an important outcome to assess. In this study we assess daily activity during both week and weekend days to ascertain if EOS patients keep up with their peers. Method: A step activity monitor was given to 11 prospectively-enrolled EOS ‘‘graduates’’ who were at least 1 year from last surgery, with instructions to wear it from morning until bedtime for 1 week. Data were collected to assess steps per day, activity time, and intensity (exercise) duration defined as O10% of daily activity time spent in continuous (O5 minutes) non-stop activity. Data were separated into week and weekend days to ascertain if participation on weekends (more self-selected activity) was different from a child’s scheduled weekday routine. Statistical analysis comparing EOS patients to 31 age matched control subjects was performed. Results: Compared to controls, we found no difference in active time or in total steps taken during the weekday or weekend. Patients took a mean 121004072 steps/weekday compared to 130492799 in controls (p5.49). On weekends patients took 108975865 vs controls 102763986, p5.75. Mean total activity time was no different for EOS patients (214 minutes weekday and 199 weekend) compared to controls (242 and 188). PFT values for EOS patients (~50% pred FVC,FEV1) did not correlate to # steps or total activity time. ‘‘Exercise’’ time revealed 4/ 11 (36%) EOS patients spent at least 10% of weekdays at non-stop activity level , while 9/31 (29%, n.s.) of controls met the same criteria. On weekends, only 2/11 (18%) EOS patients met that criteria compared to 10/ 31 (32%) in the control group. Conclusion: PFT values in EOS patients suggest pulmonary limitation; however, daily activity measures suggest no significant difference in activity in patients with EOS compared to their peers. Activity monitors are used as objective measures of daily activity following intervention and may be a more reliable outcome tool in the EOS population. Author disclosures: C.E. Johnston: None. W. Stevens, Jr.: None. K.A. Jeans: None.
(4 markers) worn on the back of the spine; c) With precise measurements made with a 3D digitizer on the synthetic spine (reference). Complementary measurements were done with the EOS X-ray system (factory calibrated). Results: On average, with the non-EOS radiographs, difference of 4 was found for the angular measurements with average differences up to 4.7 for the Cobb angles. This was not influenced by the calibration technique. Important differences were found for the linear measurements when using uncalibrated radiographs. For instance (Fig. 1b), with the radiographic ruler, the spine height error ranged 80 to 161 mm (18-41% magnification). Using the calibration device worn on the patient, this error was reduced to 4.6 1.8 mm. For the other linear measurements, the mean difference ranged 5.86.7 mm for the non-EOS radiographs, and was reduced approximately 50% when scaling using the calibration device. The measurements with the EOS radiographs had differences below 2 and 2.8 mm. Conclusion: Due to the difference between the radiographic settings and perspective projection magnification, scoliosis linear measurements could NOT accurately be made and compared, except when using calibrated radiographs or a calibration device worn on the patient (not a ruler on the radiographic cassette).
Author disclosures: C. Aubin: A; Research Grant - Natural Sciences and Engineering Research Council of Canada (Discovery Grant; Industrial Research Chair Program with Medtronic of Canada). B; Medtronic (contract through the University). C. Bellefleur: A; National Sciences and Engineering Research Council of Canada (Industrial Research Chair Program with Medtronic Canada). S. Parent: A; Fonds de Recherche Quebec - Sante, Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, Orthopedic Research and Education Foundation, Setting Scoliosi. B; EOS-Imaging, Medtronic, DePuy Synthes Spine.. D; Spinologics. H. Labelle: A; IRSC, DePuy Spine. D; Spinologics. Paper #11
Paper #10 Importance of Calibration for the Radiographic Assessment of Fusionless Treatment of Pediatric Scoliosis Carl-Eric Aubin, Christian Bellefleur, Stefan Parent, Hubert Labelle
Results at Skeletal Maturity of a Fusionless Technique for P rog re s s i v e S c o l i os i s . A n al y s i s o f F i n al C or re c t i o n a n d Complications in 33 Patients Lotfi Miladi, Thierry Odent, Nejib Khouri, Christophe Glorion
Introduction: Linear and angular radiographic measurements are commonly used for the immediate and follow-up assessment of fusionless treatment of pediatric scoliosis. Our aim was to demonstrate the importance of radiographic calibration to accurately measure and monitor the correction over time. Methods: Ten different synthetic spine configurations with various spinal shapes and scoliotic deformities were radiographed using a ‘‘non-EOS’’ radiographic system with different acquisition settings: radiographic source to film distance: 1830-1873 mm; distance of the patient spine to the cassette: 175-464 mm; AP and PA. For each montage (Fig. 1a), angular (Cobb angles, kyphosis, lordosis, .) and linear measurements (coronal and sagittal balance, spine height, apical vertebra translation, .) were performed: a) Directly on the X-rays and scaling the measurements with a radiographic ruler; b) Scaling the measurements using a calibration device
Introduction: Fusionless techniques are usually used after failure of conservative treatment, but the complication rate is high. We report the results at skeletal maturity of 33 consecutive patients operated on for a progressive scoliosis with an original single growing rod construct inserted with a mini invasive approach. Methods: 33 children with progressive scoliosis from various etiologies were reviewed at skeletal maturity. Mean age at index surgery was 10 years and mean follow-up 5a 9m. 20 patients had arthrodesis at a mean age of 15 years 3 months, and 13 patients still have the rod without arthrodesis at the end of treatment. The technique relies on a single submuscular rod fixed by a proximal claw with 2 supralaminar hooks and 1 pedicle hook, and two pedicle screws distally. The reserve for the rod lengthening was located distally. The principles of rod position, contouring and anchorage was to obtain in the frontal plane a vertical rod parallel to the CSVL, and in the
615
mainly of patients with minimal to mild asthma. Patients were excluded if there was chest or spine deformity. This list was cross-referenced to Radiology database to identify all patients who had a chest radiograph, within 2 months of the PFT study. 1797 PFT studies were identified. After applying the inclusion and exclusion criteria, and eliminating duplicates, 149 patients remained for analysis. PFT data collected included absolute FVC, %-predicted FVC, absolute FEV1, and %-predicted FEV1. Radiographic measurements on the chest radiograph included T1-T12 height, Coronal Chest Width (CCW) and Space Available for the Lung (SAL) bilaterally. Results: There were 149 patients which satisfied the inclusion and exclusion criteria. Mean age was 12.4 years, and %-predicted FEV1 and FVC were 106.9% and 103.9%, respectively. Mean T1-T12 height was 25.6 cm, CCW 25.5 cm, SAL bilaterally was 19.0 cm. FEV1 and FVC values, and radiographic values of T1-T12 height, CCW and SAL are shown in Graphs 1 and 2. A sub-cohort of patients was created of patients with T1-T12 height of 22-24 cm, hence patients who should have adequate pulmonary development at maturity. 21 patients (11 female, 10 male) were identified (see Table 1). Absolute FEV1 and FVC were 1.97 l and 2.17 l, respectively. Spirometric standards for healthy adult lifetime nonsmokers, by Gore et al, were utilized to assess the impact of T1-T12 shortening on PFT values. By inputting the mean FEV1 and FVC values for the 22-24 cm T1-T12 height group, and mean height of females (163.41 cm) and males (168.7 cm) in our cohort the %-predicted PFT values were calculated. Calculating for 15 year old females the FEV1 and FVC %-predicted was 46% and 44%; for males FEV1 was 43% and FVC 42% predicted, respectively. Conclusion: T1-T12 height at skeletal maturity of 22 cm may not be enough to guarantee patients will have an asymptomatic pulmonary status. Though this analysis does not take into consideration radial expansion of the chest during maturity, the %-predicted FEV1 and FVC values are concerning, and deserve further analysis.
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Abstracts / Spine Deformity 3 (2015) 612e629
Author disclosures: J.C. Smith: None. M. Kerstein: None. J. Gregory: None. S.J. Luhmann: B; Medtronic, Stryker, Orthofix. C; Medtronic, Stryker. F; Globus Medical, Lippincott. Paper #9 Step Activity Monitoring to Assess Functional Outcome in EOS ‘‘Graduates’’ Charles E. Johnston, MD, Wilshaw Stevens, Jr, BS, Kelly A. Jeans, MS Introduction: EOS patients are suspected to have impaired pulmonary function in spite of treatment. The clinical success of maximizing lung capacity using growth-friendly constructs before spinal fusion is somewhat unproven due to outcome measures of limited correlation to actual function. Understanding a patient’s ability to participate with peers and daily function is an important outcome to assess. In this study we assess daily activity during both week and weekend days to ascertain if EOS patients keep up with their peers. Method: A step activity monitor was given to 11 prospectively-enrolled EOS ‘‘graduates’’ who were at least 1 year from last surgery, with instructions to wear it from morning until bedtime for 1 week. Data were collected to assess steps per day, activity time, and intensity (exercise) duration defined as O10% of daily activity time spent in continuous (O5 minutes) non-stop activity. Data were separated into week and weekend days to ascertain if participation on weekends (more self-selected activity) was different from a child’s scheduled weekday routine. Statistical analysis comparing EOS patients to 31 age matched control subjects was performed. Results: Compared to controls, we found no difference in active time or in total steps taken during the weekday or weekend. Patients took a mean 121004072 steps/weekday compared to 130492799 in controls (p5.49). On weekends patients took 108975865 vs controls 102763986, p5.75. Mean total activity time was no different for EOS patients (214 minutes weekday and 199 weekend) compared to controls (242 and 188). PFT values for EOS patients (~50% pred FVC,FEV1) did not correlate to # steps or total activity time. ‘‘Exercise’’ time revealed 4/ 11 (36%) EOS patients spent at least 10% of weekdays at non-stop activity level , while 9/31 (29%, n.s.) of controls met the same criteria. On weekends, only 2/11 (18%) EOS patients met that criteria compared to 10/ 31 (32%) in the control group. Conclusion: PFT values in EOS patients suggest pulmonary limitation; however, daily activity measures suggest no significant difference in activity in patients with EOS compared to their peers. Activity monitors are used as objective measures of daily activity following intervention and may be a more reliable outcome tool in the EOS population. Author disclosures: C.E. Johnston: None. W. Stevens, Jr.: None. K.A. Jeans: None.
(4 markers) worn on the back of the spine; c) With precise measurements made with a 3D digitizer on the synthetic spine (reference). Complementary measurements were done with the EOS X-ray system (factory calibrated). Results: On average, with the non-EOS radiographs, difference of 4 was found for the angular measurements with average differences up to 4.7 for the Cobb angles. This was not influenced by the calibration technique. Important differences were found for the linear measurements when using uncalibrated radiographs. For instance (Fig. 1b), with the radiographic ruler, the spine height error ranged 80 to 161 mm (18-41% magnification). Using the calibration device worn on the patient, this error was reduced to 4.6 1.8 mm. For the other linear measurements, the mean difference ranged 5.86.7 mm for the non-EOS radiographs, and was reduced approximately 50% when scaling using the calibration device. The measurements with the EOS radiographs had differences below 2 and 2.8 mm. Conclusion: Due to the difference between the radiographic settings and perspective projection magnification, scoliosis linear measurements could NOT accurately be made and compared, except when using calibrated radiographs or a calibration device worn on the patient (not a ruler on the radiographic cassette).
Author disclosures: C. Aubin: A; Research Grant - Natural Sciences and Engineering Research Council of Canada (Discovery Grant; Industrial Research Chair Program with Medtronic of Canada). B; Medtronic (contract through the University). C. Bellefleur: A; National Sciences and Engineering Research Council of Canada (Industrial Research Chair Program with Medtronic Canada). S. Parent: A; Fonds de Recherche Quebec - Sante, Canadian Institutes of Health Research, Natural Sciences and Engineering Research Council of Canada, Orthopedic Research and Education Foundation, Setting Scoliosi. B; EOS-Imaging, Medtronic, DePuy Synthes Spine.. D; Spinologics. H. Labelle: A; IRSC, DePuy Spine. D; Spinologics. Paper #11
Paper #10 Importance of Calibration for the Radiographic Assessment of Fusionless Treatment of Pediatric Scoliosis Carl-Eric Aubin, Christian Bellefleur, Stefan Parent, Hubert Labelle
Results at Skeletal Maturity of a Fusionless Technique for P rog re s s i v e S c o l i os i s . A n al y s i s o f F i n al C or re c t i o n a n d Complications in 33 Patients Lotfi Miladi, Thierry Odent, Nejib Khouri, Christophe Glorion
Introduction: Linear and angular radiographic measurements are commonly used for the immediate and follow-up assessment of fusionless treatment of pediatric scoliosis. Our aim was to demonstrate the importance of radiographic calibration to accurately measure and monitor the correction over time. Methods: Ten different synthetic spine configurations with various spinal shapes and scoliotic deformities were radiographed using a ‘‘non-EOS’’ radiographic system with different acquisition settings: radiographic source to film distance: 1830-1873 mm; distance of the patient spine to the cassette: 175-464 mm; AP and PA. For each montage (Fig. 1a), angular (Cobb angles, kyphosis, lordosis, .) and linear measurements (coronal and sagittal balance, spine height, apical vertebra translation, .) were performed: a) Directly on the X-rays and scaling the measurements with a radiographic ruler; b) Scaling the measurements using a calibration device
Introduction: Fusionless techniques are usually used after failure of conservative treatment, but the complication rate is high. We report the results at skeletal maturity of 33 consecutive patients operated on for a progressive scoliosis with an original single growing rod construct inserted with a mini invasive approach. Methods: 33 children with progressive scoliosis from various etiologies were reviewed at skeletal maturity. Mean age at index surgery was 10 years and mean follow-up 5a 9m. 20 patients had arthrodesis at a mean age of 15 years 3 months, and 13 patients still have the rod without arthrodesis at the end of treatment. The technique relies on a single submuscular rod fixed by a proximal claw with 2 supralaminar hooks and 1 pedicle hook, and two pedicle screws distally. The reserve for the rod lengthening was located distally. The principles of rod position, contouring and anchorage was to obtain in the frontal plane a vertical rod parallel to the CSVL, and in the