Long-term Outcomes of Operatively and Non-Operatively Treated Spina Bifida Scoliosis By Amir Khoshbin A thesis submitted in conformity with the requirements for the degree of Master of Science Graduate Department of Institute of Medical Science In the University of Toronto © Copyright by Amir Khoshbin 2014 Long-term Outcomes of Operatively and Non-Operatively Treated Spina Bifida Scoliosis Amir Khoshbin Master of Science Institute of Medical Science University of Toronto 2014 ABSTRACT: Background The purpose of this study was to evaluate outcomes in Spina Bifida Cystica adults, treated non-operatively or operatively for scoliosis during childhood. Methods Patients with SBC scoliosis (minimum Cobb angle >50o) treated at the Hospital for Sick Children or the Children’s Hospital of Eastern Ontario (1991-2007 inclusive) were recruited. In addition to clinical and radiological assessments, health related quality of life (HRQOL) outcomes included the: a) Spina Bifida Spine Questionnaire (SBSQ) and b) Medical Outcomes Study-36 Item Short Form Health Survey (SF-36). Results The operative and non-operative patients were statistically similar at baseline on the following variables: a) age, b) sex, c) living situation, d) ambulation, and e) ii neurological motor level. At an average follow-up of 14.1+4.3 years, groups were statistically similar with respect to: a) SF-36 and b) SBSQ scores. Conclusion Spinal fusion in SBC scoliosis corrected coronal deformity and stopped progression, but had no overall effect on HRQOL. iii ACKNOWLEDGMENTS: I would like to thank the following staff and colleagues for their help and guidance throughout this thesis. Lilian Wong Western University: Schulich School of Medicine and Dentistry, London, Ontario, Canada B.Sc. Peggy W. Law The Hospital for Sick Children, Toronto, Ontario, Canada B.Sc. M.Sc. Derek Stephens The Hospital for Sick Children, Toronto, Ontario, Canada B.Sc. M.Sc. Kathryn Doughty Shriners Hospitals for Children, Los Angeles, California, USA B.A. MD MPH MSc. Liora Caspi The Hospital for Sick Children, Toronto, Ontario, FAACS Canada M.Sc. Aileen M. Davis University Health Network: Division of Health Care and Outcomes Research, Toronto Western Research PhD Andrew Howard The HospitalInstitute, for Toronto, Sick Children, Ontario, Toronto, Canada Ontario, Canada MD MSc. FRCSC James G. Jarvis The Children’s Hospital of Eastern Ontario, Ottawa, Ontario, Canada MD FRCSC James G. Wright The Hospital for Sick Children, Toronto, Ontario, Canada MD MPH FRCSC iv Table of Contents LIST OF ABBREVIATIONS ______________________________________________________________ vii 1. INTRODUCTION ________________________________________________________________________ 1 1.1 Epidemiology _______________________________________________________________________________ 1 1.2 Aetiology ____________________________________________________________________________________ 1 1.3 Scoliosis _____________________________________________________________________________________ 2 1.4 Treatment Options ________________________________________________________________________ 3 1.4.1 Operative Outcomes _____________________________________________________________________ 4 1.4.2 Complications of Spinal Arthrodesis ___________________________________________________ 7 1.4.3 Health Related Quality of Life (HRQOL) _______________________________________________ 7 1.5 Literature Limitations ___________________________________________________________________ 10 1.6 Research Aims ____________________________________________________________________________ 11 2. METHODS ______________________________________________________________________________ 13 2.1 Study Population _________________________________________________________________________ 13 2.2 Inclusion and Exclusion Criteria _______________________________________________________ 13 2.3 Study Enrolment __________________________________________________________________________ 14 2.4 Recruitment Strategies __________________________________________________________________ 14 2.5 Baseline Assessment _____________________________________________________________________ 16 2.6 Radiological Assessment ________________________________________________________________ 18 2.7 Clinical assessment _______________________________________________________________________ 19 2.8 Health Related Quality of Life Outcomes ______________________________________________ 20 2.9 Data Analysis ______________________________________________________________________________ 22 3. RESULTS _______________________________________________________________________________ 26 3.1 Baseline ____________________________________________________________________________________ 26 3.2 Peri- & Post-Operative (Operative Participants) ____________________________________ 27 3.3 Follow-up __________________________________________________________________________________ 28 4. DISCUSSION/CONCLUSION __________________________________________________________ 31 4.1 Study Limitations _________________________________________________________________________ 35 4.2 Future Directions _________________________________________________________________________ 39 5. TABLES: ________________________________________________________________________________ 41 5.1 Table 1: Baseline Assessments _________________________________________________________ 41 5.2 Table 2: Peri-operative and Post-operative (Operative Patients) ________________ 42 5.3 Table 3: Follow-up Assessments _______________________________________________________ 43 5.4 Table 4: HRQOL Outcomes at Follow-up ______________________________________________ 44 6. FIGURES: _______________________________________________________________________________ 45 6.1 Figure 1: Follow-up Cobb Angles and SF-36 PCS (filled circles) & MCS (unfilled squares) scores for All Patients (N=45). Best-fit lines for PCS (solid line) and MCS (dashed line) also depicted. _________________________________________________________________ 45 v 6.2 Figure 2: Follow-up Cobb Angles and SF-36 PCS (filled circles) & MCS (unfilled squares) scores for Operative (N=34) and Non-operative (N=11) Patients. Best-fit lines for PCS (solid line) and MCS (dashed line) also depicted. ________________________ 46 6.3 Figure 3: a) Follow-up SF-36 PCS Scores of Ambulatory (N=10) and Non- Ambulatory Patients (N=35) and b) SF-36 MCS Scores of Ambulatory and Non- Ambulatory Patients _________________________________________________________________________ 47 7. APPENDICES ___________________________________________________________________________ 48 7.1 Appendix 1: Research Ethics Board Decision and Amendment for Extra Site __ 48 7.2 Appendix 2: US English-language Medical Outcome Study 36-item Short Form Health Survey (SF-36v2®) ___________________________________________________________________ 51 7.3 Appendix 3: Spina Bifida Spine Questionnaire _______________________________________ 53 7.4 Appendix 4: Hoffer Classification ______________________________________________________ 55 7.5 Appendix 5: Neurological Motor Level ________________________________________________ 56 7.6 Appendix 6: Sitting Balance Scale ______________________________________________________ 57 7.7 Appendix 7: Patient Consent form _____________________________________________________ 58 7.8 Appendix 8: Parent Consent Form _____________________________________________________ 69 7.9 Appendix 9: Baseline Characteristics of Study Responders versus Non- Responders ____________________________________________________________________________________ 80 7.10 Appendix 10: Sample Size Calculation _______________________________________________ 81 7.11 Appendix 11: Post-Hoc Power Analysis _____________________________________________ 82 7.12 Appendix 12: Non-parametric Testing for HRQOL Scores ________________________ 83 8. REFERENCES: __________________________________________________________________________ 84 vi LIST OF ABBREVIATIONS SB Spina Bifida SBC Spina Bifida Cystica HSC Hospital for Sick Children CHEO Children’s Hospital of Eastern Ontario NML Neurological Motor Level T- Thoracic L- Lumbar AP Anterior-Posterior ASA American Society of Anesthesiologists Physical Status Classification BMI Body Mass Index pRBC Packed Red Blood Cells PFT Pulmonary Function Test %FVC Percent Predicted Forced Vital Capacity %FEV1 Percent Predicted Forced Expiratory Volume in 1 Second VP Ventriculoperitoneal G- Gastrostomy SBHAO Spina Bifida and Hydrocephalus Association of Ontario SRS Scoliosis Research Society SSI Surgical site infections CRID Clavicle Rib Intersection Difference HRQOL Health Related Quality of Life ADL Activities of Daily Living SF-36 US English-language Medical Outcome Study 36-item Short Form Health Survey PF Physical Functioning RP Role-Physical BP Bodily Pain vii GH General Health Perception VT Energy/Vitality SF Social Functioning RE Role Emotional MH Mental Health PCS Physical Component Scale MCS Mental Component Scale WHO World Health Organization HRQOL-SB Spina Bifida Health Related Quality of Life Questionnaire ASK Activities Scale for Kids PedsQL Paediatric Quality of Life Inventory 4.0 SBSQ Spina Bifida Spine Questionnaire SBS Sitting Balance Scale ASPINE Adolescents with Spina Bifida in the Netherlands SRS Scoliosis Research Society MID Minimal Important Difference PRO Patient Reported Outcomes FDA Food and Drug Administration MD Mean differences CI Confidence Intervals SD Standard Deviation N Sample Size cm Centimetres mm Millimetres o