Session 17: Spine
Fredag den 26. oktober
13:30 - 15:00
Lokale: Vingsal 2
Chairmen: Kristian Høy og Rikke Rousing
Simon Toftgaard Skov, Haisheng Li, Jan Duedal Rölfing, Marianne Vigh-Larsen, Cody Bünger
Elective Surgery Center, Silkeborg Regional Hospital ; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Surgery & Anesthesiology, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital
Background: Magnetically controlled growing-rods (MCGRs) have gained popularity because they offer non-surgical lengthening procedures in early-onset scoliosis (EOS) instead of semi-annual open surgery elongations with traditional growing rods. Many aspects of MCGR treatment have been investigated, but pain in conjunction with distraction is only sparsely described in the literature.
Purpose / Aim of Study: The aim was to investigate the pain associated with MCGR lengthening procedures.
Materials and Methods: Prospective cohort study assessing pain intensity of 25 EOS patients before, during and after MCGR lengthening procedures in an outpatient setup. They underwent at least two (range 2-16) lengthening procedures prior to this study. The pain intensity was estimated using patient-reported Faces Pain Scale (FPS-R), caregiver-reported pain numeric rating scale (NRS), and NRS and revised Face, Legs, Activity, Cry, Consolability scale (r-FLACC) by two medically trained observers. The inter- rater reliability and correlation between instruments were analyzed.
Findings / Results: 23 of 25 EOS patients (8-16 years old) with mixed etiology were able to self-report pain. The average pain intensity was mild, median 1 (range 0-6) on all four instruments on a 0-to-10 scale. Afterwards, 22 patients (88%) were completely pain-free and the remaining 3 patients had a pain score of 1. MCGR stalling (i.e. clunking) was encountered in 56% of the patients without impact on the pain intensity.
Conclusions: The average maximum pain intensities during the lengthening procedures were mild and pain ceased within few minutes. Inter-rater reliability was good to excellent for NRS and r-FLACC, and there were high correlations between all the four instruments, indicating high criterion validity.
Elective Surgery Center, Silkeborg Regional Hospital ; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital; Department of Surgery & Anesthesiology, Aarhus University Hospital; Department of Orthopaedic Surgery, Aarhus University Hospital
Background: Magnetically controlled growing-rods (MCGRs) have gained popularity because they offer non-surgical lengthening procedures in early-onset scoliosis (EOS) instead of semi-annual open surgery elongations with traditional growing rods. Many aspects of MCGR treatment have been investigated, but pain in conjunction with distraction is only sparsely described in the literature.
Purpose / Aim of Study: The aim was to investigate the pain associated with MCGR lengthening procedures.
Materials and Methods: Prospective cohort study assessing pain intensity of 25 EOS patients before, during and after MCGR lengthening procedures in an outpatient setup. They underwent at least two (range 2-16) lengthening procedures prior to this study. The pain intensity was estimated using patient-reported Faces Pain Scale (FPS-R), caregiver-reported pain numeric rating scale (NRS), and NRS and revised Face, Legs, Activity, Cry, Consolability scale (r-FLACC) by two medically trained observers. The inter- rater reliability and correlation between instruments were analyzed.
Findings / Results: 23 of 25 EOS patients (8-16 years old) with mixed etiology were able to self-report pain. The average pain intensity was mild, median 1 (range 0-6) on all four instruments on a 0-to-10 scale. Afterwards, 22 patients (88%) were completely pain-free and the remaining 3 patients had a pain score of 1. MCGR stalling (i.e. clunking) was encountered in 56% of the patients without impact on the pain intensity.
Conclusions: The average maximum pain intensities during the lengthening procedures were mild and pain ceased within few minutes. Inter-rater reliability was good to excellent for NRS and r-FLACC, and there were high correlations between all the four instruments, indicating high criterion validity.
Søren Ohrt-Nissen, Markus Lastikka, Thomas Borbjerg Andersen, Ilkka Helenius, Martin Gehrchen
Department of Orthopaedic surgery, Spine Unit, Rigshospitalet; Department of Pediatric Orthopedic Surgery, Turku University Hospital; Department of Orthopaedic surgery, Spine Unit, Rigshospitalet; Department of Pediatric Orthopedic Surgery, Turku University Hospital; Department of Orthopaedic surgery, Spine Unit, Rigshospitalet
Background: The full-time Boston brace is a well-established treatment in adolescent idiopathic scoliosis (AIS). The part-time Providence brace has become popular but some studies suggest that is not suitable for thoracic AIS.
Purpose / Aim of Study: To compare treatment efficacy between the Boston full-time brace and the Providence part-time brace in main thoracic AIS.
Materials and Methods: Patients were treated with either the Boston brace (n=37) or the Providence brace (n=40) at two different institutions. Inclusion criteria were Risser grade ≤2, major curve between 25-40° with the apex of the curve between T7 and T11 vertebrae. Two- year follow-up was available in all patients unless brace treatment had reached endpoint. The primary outcome measure was main curve progression to ≥45°.
Findings / Results: Median age was 12.6 years and median treatment length at follow-up was 25 months (IQR:18-32) with no difference between the groups (p ≥ 0.116). Initial median main Cobb angle was 29° (IQR:27-33) and 36° (IQR:33-38) in the Boston and Providence group, respectively (p<0.001). At follow-up, 13 patients (35%) had progressed to ≥45° in the Boston group vs. 16 patients (40%) in the Providence group (p = 0.838). Twenty-three patients (62%) had progressed by more than five degrees in the Boston group vs. 22 patients (55%) in the Providence group (p=0.685). The secondary thoracolumbar/lumbar curve progressed by more than five degrees in 14 (38%) and 18 (45%) in the Boston and Providence groups, respectively (p=0.548).
Conclusions: Despite a larger initial curve size in the Providence group, progression of more than 5 degrees or to surgical indication area was similar in the Boston group. Our results indicate that night-time bracing is a viable alternative to full-time bracing also in main thoracic AIS.
Department of Orthopaedic surgery, Spine Unit, Rigshospitalet; Department of Pediatric Orthopedic Surgery, Turku University Hospital; Department of Orthopaedic surgery, Spine Unit, Rigshospitalet; Department of Pediatric Orthopedic Surgery, Turku University Hospital; Department of Orthopaedic surgery, Spine Unit, Rigshospitalet
Background: The full-time Boston brace is a well-established treatment in adolescent idiopathic scoliosis (AIS). The part-time Providence brace has become popular but some studies suggest that is not suitable for thoracic AIS.
Purpose / Aim of Study: To compare treatment efficacy between the Boston full-time brace and the Providence part-time brace in main thoracic AIS.
Materials and Methods: Patients were treated with either the Boston brace (n=37) or the Providence brace (n=40) at two different institutions. Inclusion criteria were Risser grade ≤2, major curve between 25-40° with the apex of the curve between T7 and T11 vertebrae. Two- year follow-up was available in all patients unless brace treatment had reached endpoint. The primary outcome measure was main curve progression to ≥45°.
Findings / Results: Median age was 12.6 years and median treatment length at follow-up was 25 months (IQR:18-32) with no difference between the groups (p ≥ 0.116). Initial median main Cobb angle was 29° (IQR:27-33) and 36° (IQR:33-38) in the Boston and Providence group, respectively (p<0.001). At follow-up, 13 patients (35%) had progressed to ≥45° in the Boston group vs. 16 patients (40%) in the Providence group (p = 0.838). Twenty-three patients (62%) had progressed by more than five degrees in the Boston group vs. 22 patients (55%) in the Providence group (p=0.685). The secondary thoracolumbar/lumbar curve progressed by more than five degrees in 14 (38%) and 18 (45%) in the Boston and Providence groups, respectively (p=0.548).
Conclusions: Despite a larger initial curve size in the Providence group, progression of more than 5 degrees or to surgical indication area was similar in the Boston group. Our results indicate that night-time bracing is a viable alternative to full-time bracing also in main thoracic AIS.
Lærke Ragborg, Casper Dragsted, Benny Dahl, Martin Gehrchen
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas, USA; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet
Background: Previous studies have highlighted the impact on HRQOL in adolescent patients with SK; however, sparse information is available regarding the long-term effects of SK on HRQOL. Thoracolumbar (TL) SK has been associated with increased back pain compared to thoracic (Th) SK. Moreover, spino-pelvic parameters have been reported to impact on HRQOL.
Purpose / Aim of Study: To investigate the impact Scheuermann Kyphosis (SK) has on Health Related Quality Of Life (HRQOL) in adult patients and compare it to the general population along assessing whether location of the kyphosis affects pelvic parameters and HRQOL.
Materials and Methods: Of a cohort of 242 patients seen for a pediatric spinal deformity in the years 1972-1982 in the outpatient clinic, 55 had radiologically verified SK. Thirty-eight participated in the study and responded to HRQOL questionnaires, and 34 had radiographs taken. Patients were divided into two groups according to location of the SK apex: Thoracic (Th) above Th10 and Thoracolumbar (TL) from Th10 and below. Spino-pelvic parameters were measured for all radiographs. The HRQOL scores for all SK patients were compared with normative data from a Scandinavian population.
Findings / Results: Mean follow-up was 39±1.6 years and mean age at follow-up was 53±2.4 years. We found lower score in the TL group for SRS-22r function domain (p=0.027) compared with the Th group, but no significant difference in the remaining domains and SRS-22r subscore (p>0.18). Patients had significantly lower mean scores compared to normative values on SRS-22r domains pain (p=0.049) and self-image (p=0.006), but no statistically significant difference on SRS-22r subscore (p=0.064). There was no difference in pelvic parameters between the two SK groups.
Conclusions: We found a lower HRQOL in adult patients with SK 39 years after diagnosis regarding SRS-22r domains pain and self-image, and a tendency towards lower overall HRQOL compared with a background population. The location of the SK apex did not seem to have an overall impact on HRQOL. There was no difference in pelvic parameters in the two groups.
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas, USA; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet
Background: Previous studies have highlighted the impact on HRQOL in adolescent patients with SK; however, sparse information is available regarding the long-term effects of SK on HRQOL. Thoracolumbar (TL) SK has been associated with increased back pain compared to thoracic (Th) SK. Moreover, spino-pelvic parameters have been reported to impact on HRQOL.
Purpose / Aim of Study: To investigate the impact Scheuermann Kyphosis (SK) has on Health Related Quality Of Life (HRQOL) in adult patients and compare it to the general population along assessing whether location of the kyphosis affects pelvic parameters and HRQOL.
Materials and Methods: Of a cohort of 242 patients seen for a pediatric spinal deformity in the years 1972-1982 in the outpatient clinic, 55 had radiologically verified SK. Thirty-eight participated in the study and responded to HRQOL questionnaires, and 34 had radiographs taken. Patients were divided into two groups according to location of the SK apex: Thoracic (Th) above Th10 and Thoracolumbar (TL) from Th10 and below. Spino-pelvic parameters were measured for all radiographs. The HRQOL scores for all SK patients were compared with normative data from a Scandinavian population.
Findings / Results: Mean follow-up was 39±1.6 years and mean age at follow-up was 53±2.4 years. We found lower score in the TL group for SRS-22r function domain (p=0.027) compared with the Th group, but no significant difference in the remaining domains and SRS-22r subscore (p>0.18). Patients had significantly lower mean scores compared to normative values on SRS-22r domains pain (p=0.049) and self-image (p=0.006), but no statistically significant difference on SRS-22r subscore (p=0.064). There was no difference in pelvic parameters between the two SK groups.
Conclusions: We found a lower HRQOL in adult patients with SK 39 years after diagnosis regarding SRS-22r domains pain and self-image, and a tendency towards lower overall HRQOL compared with a background population. The location of the SK apex did not seem to have an overall impact on HRQOL. There was no difference in pelvic parameters in the two groups.
Tanvir Johanning Bari, Sven Karstensen, Mathias Dahl Sørensen, Martin Gehrchen, John Street, Benny Dahl
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Combined Neurosurgical and Orthopedic Spine Program, Vancouver General Hospital, University of British Columbia, Canada; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital & Baylor College of Medicine, TX, USA
Background: Adverse events (AEs) in spine surgery are attracting attention. Recent studies suggest that prospective registration more accurately reflects the true incidence. To our knowledge, no previous study has investigated prospectively registered AEs´ influence on hospital readmission following spine surgery.
Purpose / Aim of Study: To determine the frequency of unplanned readmissions after complex spine surgery, and to investigate if prospectively registered AEs can predict readmissions.
Materials and Methods: All patients undergoing surgery, at our tertiary referral center, were consecutively and prospectively included in 2013. Demographics and perioperative AEs were registered using the Spine AdVerse Events Severity system. Patients were followed for a minimum of 2 years. A competing risk survival model was used to estimate rates of readmissions with death as a competing risk. Multivariate logistic regression analysis and proportional odds survival models were used to assess predictors of i) 30-day readmission to any department and ii) readmission to a spine center at any time point. Results were reported as odds ratios (OR) with 95% confidence intervals (95%CI).
Findings / Results: We included 679 patients undergoing surgery for various spine pathologies (deformity, degenerative, tumor, trauma and infection). Within 2 years of index discharge, 443 (65%) were readmitted. Only 20% of readmissions were to a spine center. Cumulative incidence (95%CI) of readmission was estimated to 13% (10-16%) at 30 days, 26% (23-30%) at 90 days, 50% (46- 54%) at 1 year, and 59% (55-63%) at 2 years following discharge. Increased odds of 30-day readmission were correlated to intraoperative hypotension (P=0.02) and major intraoperative blood loss (P<0.01). Readmission to a spine center at any time point was associated to number of instrumented vertebra (P=0.047), major intraoperative AE (P=0.01) and intraoperative hypotension (P<0.01).
Conclusions: Readmission following complex spine surgery was more frequent than previously reported. Factors related to major intraoperative blood loss were associated to increased odds of readmission. This should be considered during planning of postoperative observation and care.
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Combined Neurosurgical and Orthopedic Spine Program, Vancouver General Hospital, University of British Columbia, Canada; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital & Baylor College of Medicine, TX, USA
Background: Adverse events (AEs) in spine surgery are attracting attention. Recent studies suggest that prospective registration more accurately reflects the true incidence. To our knowledge, no previous study has investigated prospectively registered AEs´ influence on hospital readmission following spine surgery.
Purpose / Aim of Study: To determine the frequency of unplanned readmissions after complex spine surgery, and to investigate if prospectively registered AEs can predict readmissions.
Materials and Methods: All patients undergoing surgery, at our tertiary referral center, were consecutively and prospectively included in 2013. Demographics and perioperative AEs were registered using the Spine AdVerse Events Severity system. Patients were followed for a minimum of 2 years. A competing risk survival model was used to estimate rates of readmissions with death as a competing risk. Multivariate logistic regression analysis and proportional odds survival models were used to assess predictors of i) 30-day readmission to any department and ii) readmission to a spine center at any time point. Results were reported as odds ratios (OR) with 95% confidence intervals (95%CI).
Findings / Results: We included 679 patients undergoing surgery for various spine pathologies (deformity, degenerative, tumor, trauma and infection). Within 2 years of index discharge, 443 (65%) were readmitted. Only 20% of readmissions were to a spine center. Cumulative incidence (95%CI) of readmission was estimated to 13% (10-16%) at 30 days, 26% (23-30%) at 90 days, 50% (46- 54%) at 1 year, and 59% (55-63%) at 2 years following discharge. Increased odds of 30-day readmission were correlated to intraoperative hypotension (P=0.02) and major intraoperative blood loss (P<0.01). Readmission to a spine center at any time point was associated to number of instrumented vertebra (P=0.047), major intraoperative AE (P=0.01) and intraoperative hypotension (P<0.01).
Conclusions: Readmission following complex spine surgery was more frequent than previously reported. Factors related to major intraoperative blood loss were associated to increased odds of readmission. This should be considered during planning of postoperative observation and care.
Peter Udby, Søren Ohrt-Nissen, Tom Bendix, Michael Rud Lassen, Stig Brorson, Carreon Leah , Mikkel Østerheden Andersen
Spine Unit, Zealand University Hospital.; Spine Unit, Rigshospitalet; VRR, Rigshospitalet; Spine Unit, Zealand University Hospital.; Orthopedic research unit, Zealand University Hospital.; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital
Background: MRI is used extensively as a diagnostic tool to evaluate and guide treatment of patients with low back pain. However, the long-term association between degenerative MRI findings and disability is unclear.
Purpose / Aim of Study: To assess whether long-term disability is associated with baseline disc degeneration, Modic Changes or facet joint degeneration in low back pain patients.
Materials and Methods: In 2004-2005, patients aged 18-60 with daily LBP were enrolled in an RCT study and lumbar MRI was performed. Patients completed Roland-Morris Disability Questionnaire (RMDQ) and LBP Rating Scale for activity limitations (RS), at baseline and 13-years after the MRI. Regression analysis with 13- yr RMDQ as depend variable and baseline disc degeneration, Modic Changes and facet joint degeneration as independent variables was performed. Demographics including smoking status, BMI and weekly physical activity at leisure was included in the analysis
Findings / Results: Of 204 cases with baseline MRI, 170 (83%) were available for follow-up; of these, 88 had disc degeneration (52%), 67 had Modic Changes (39%) and 139 had facet joint degeneration (82%). Only Modic Changes and weekly physical activity at leisure impacted the model significantly, respectively standard beta coefficient of -0.15 (p=0.031) for MC and -0.51 (p<0.001) for weekly physical activity at leisure.
Conclusions: Contrary to our hypothesis, none of the degenerative MRI changes at baseline was associated with a worse outcome at 13-year follow-up. Baseline Modic Changes was associated with statistically significant less long-term disability.
Spine Unit, Zealand University Hospital.; Spine Unit, Rigshospitalet; VRR, Rigshospitalet; Spine Unit, Zealand University Hospital.; Orthopedic research unit, Zealand University Hospital.; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital
Background: MRI is used extensively as a diagnostic tool to evaluate and guide treatment of patients with low back pain. However, the long-term association between degenerative MRI findings and disability is unclear.
Purpose / Aim of Study: To assess whether long-term disability is associated with baseline disc degeneration, Modic Changes or facet joint degeneration in low back pain patients.
Materials and Methods: In 2004-2005, patients aged 18-60 with daily LBP were enrolled in an RCT study and lumbar MRI was performed. Patients completed Roland-Morris Disability Questionnaire (RMDQ) and LBP Rating Scale for activity limitations (RS), at baseline and 13-years after the MRI. Regression analysis with 13- yr RMDQ as depend variable and baseline disc degeneration, Modic Changes and facet joint degeneration as independent variables was performed. Demographics including smoking status, BMI and weekly physical activity at leisure was included in the analysis
Findings / Results: Of 204 cases with baseline MRI, 170 (83%) were available for follow-up; of these, 88 had disc degeneration (52%), 67 had Modic Changes (39%) and 139 had facet joint degeneration (82%). Only Modic Changes and weekly physical activity at leisure impacted the model significantly, respectively standard beta coefficient of -0.15 (p=0.031) for MC and -0.51 (p<0.001) for weekly physical activity at leisure.
Conclusions: Contrary to our hypothesis, none of the degenerative MRI changes at baseline was associated with a worse outcome at 13-year follow-up. Baseline Modic Changes was associated with statistically significant less long-term disability.
Tanvir Johanning Bari, Dennis Winge Hallager, Lars Valentin Hansen, Benny Dahl, Martin Gehrchen
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital and Baylor College of Medicine, TX, USA; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital
Background: 3-Column Osteotomies (3CO) allow major surgical correction of Adult Spinal Deformity (ASD); although, the risk of mechanical complications remains considerable. Previous reports of revision risk have been based on smaller cohorts or multicenter databases and none have utilized Competing Risk (CR) survival analysis.
Purpose / Aim of Study: To report the incidence of revision surgery due to mechanical failure following 3CO surgery in patients with ASD.
Materials and Methods: All ASD patients undergoing 3CO surgery from 2010-2015 at a single, tertiary institution were included. Demographics, long standing radiographs as well as intra- and postoperative complications were registered for all. A CR-model was used to estimate the incidence of revision surgery due to mechanical failure and covariates were assessed for prediction of failure and reported as odds ratios (OR) with 95% confidence intervals (95%CI).
Findings / Results: A total of 193 patients were included with two- year follow-up available for 88% (mean [IQR]: 33 [24-49] months). Mechanical failure occurred in 120 cases (62%) at any time in follow-up, the most frequent being rod breakage affecting 86 patients (45%). Cumulative incidence of revision surgery due to mechanical failure was estimated to 34% at two-years and 56% at five-years. A multivariable proportional odds model with death as competing risk showed significant higher odds of revision with increasing age (OR: 1.03; 95%CI: 1.00-1.05) and preoperative Pelvic Tilt (PT) >20° (OR: 2.14; 95%CI: 1.09-4.22). Type of 3CO, history of previous surgery, number of instrumented vertebra, as well as postoperative SRS-Schwab modifiers and Global Alignment and Proportion score were not associated with significant effects on odds of revision.
Conclusions: In a consecutive single-center cohort of patients undergoing 3CO for ASD, we found an estimated incidence of revision surgery due to mechanical failure of 34% 2-years postoperatively. Age and preoperative PT >20° were associated with elevated risks of revision.
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital and Baylor College of Medicine, TX, USA; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital
Background: 3-Column Osteotomies (3CO) allow major surgical correction of Adult Spinal Deformity (ASD); although, the risk of mechanical complications remains considerable. Previous reports of revision risk have been based on smaller cohorts or multicenter databases and none have utilized Competing Risk (CR) survival analysis.
Purpose / Aim of Study: To report the incidence of revision surgery due to mechanical failure following 3CO surgery in patients with ASD.
Materials and Methods: All ASD patients undergoing 3CO surgery from 2010-2015 at a single, tertiary institution were included. Demographics, long standing radiographs as well as intra- and postoperative complications were registered for all. A CR-model was used to estimate the incidence of revision surgery due to mechanical failure and covariates were assessed for prediction of failure and reported as odds ratios (OR) with 95% confidence intervals (95%CI).
Findings / Results: A total of 193 patients were included with two- year follow-up available for 88% (mean [IQR]: 33 [24-49] months). Mechanical failure occurred in 120 cases (62%) at any time in follow-up, the most frequent being rod breakage affecting 86 patients (45%). Cumulative incidence of revision surgery due to mechanical failure was estimated to 34% at two-years and 56% at five-years. A multivariable proportional odds model with death as competing risk showed significant higher odds of revision with increasing age (OR: 1.03; 95%CI: 1.00-1.05) and preoperative Pelvic Tilt (PT) >20° (OR: 2.14; 95%CI: 1.09-4.22). Type of 3CO, history of previous surgery, number of instrumented vertebra, as well as postoperative SRS-Schwab modifiers and Global Alignment and Proportion score were not associated with significant effects on odds of revision.
Conclusions: In a consecutive single-center cohort of patients undergoing 3CO for ASD, we found an estimated incidence of revision surgery due to mechanical failure of 34% 2-years postoperatively. Age and preoperative PT >20° were associated with elevated risks of revision.
Casper Dragsted, Sidsel Fruergaard, Mohit Jain, Deveza Deveza, John Heydemann, Søren Ohrt-Nissen, Thomas Andersen, Martin Gehrchen, Benny Dahl, Texas Children’s Hospital Spine Study Group
Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA
Background: Consensus is lacking regarding distraction frequency, amount and technique in the treatment of early-onset scoliosis (EOS) with magnetically controlled growing rods (MCGR).
Purpose / Aim of Study: Compare distraction-to-stall with estimated distraction in the treatment with MCGR.
Materials and Methods: We performed a two-center retrospective study of all children treated with MCGR from November 2013 to January 2019, having minimum one-year follow-up and undergoing minimum three distractions. Exclusion criteria were single-rod constructs and conversion cases. At one center (21 patients) we used a distraction- to-stall principle, and at the second center (18 patients) we used an estimated distraction amount principle. In distraction- to-stall, each rod was lengthened until the internal magnetic driver stopped (“clunking“) or the patient felt discomfort. In estimated distraction, a set distraction length was entered on the remote control before distraction. Both centers aimed for maximal distraction and curve correction at index surgery. Achieved lengthening was measured on radiographs and compared between the two centers using a linear mixed effects model adjusted for number of instrumented levels.
Findings / Results: Mean age at surgery was 9.5±2.0 years and 21 (55%) patients were females. Etiology of the deformity was congenital/structural (n=7), neuromuscular (n=9), syndromic (n=3) or idiopathic (n=20). Age, sex, etiology and pre- and postoperative spinal height (T1-T12 and T1-S1) did not differ between centers (p>0.46). Time between distractions were mean 17 days (95% CI 10-24) shorter in the distraction-to-stall compared with the estimated distraction group. Mechanical complications occurred in 10/39 patients, five at each center. In the linear mixed effects model, we found that achieved lengthening increased with number of instrumented levels; however, there was no significant difference between the two centers.
Conclusions: In two comparable and consecutive cohorts we found no difference in achieved lengthening between distraction-to-stall and estimated distraction lengthening principles.
Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Spine Unit, Department of Orthopaedic Surgery, Rigshospitalet; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital, TX, USA
Background: Consensus is lacking regarding distraction frequency, amount and technique in the treatment of early-onset scoliosis (EOS) with magnetically controlled growing rods (MCGR).
Purpose / Aim of Study: Compare distraction-to-stall with estimated distraction in the treatment with MCGR.
Materials and Methods: We performed a two-center retrospective study of all children treated with MCGR from November 2013 to January 2019, having minimum one-year follow-up and undergoing minimum three distractions. Exclusion criteria were single-rod constructs and conversion cases. At one center (21 patients) we used a distraction- to-stall principle, and at the second center (18 patients) we used an estimated distraction amount principle. In distraction- to-stall, each rod was lengthened until the internal magnetic driver stopped (“clunking“) or the patient felt discomfort. In estimated distraction, a set distraction length was entered on the remote control before distraction. Both centers aimed for maximal distraction and curve correction at index surgery. Achieved lengthening was measured on radiographs and compared between the two centers using a linear mixed effects model adjusted for number of instrumented levels.
Findings / Results: Mean age at surgery was 9.5±2.0 years and 21 (55%) patients were females. Etiology of the deformity was congenital/structural (n=7), neuromuscular (n=9), syndromic (n=3) or idiopathic (n=20). Age, sex, etiology and pre- and postoperative spinal height (T1-T12 and T1-S1) did not differ between centers (p>0.46). Time between distractions were mean 17 days (95% CI 10-24) shorter in the distraction-to-stall compared with the estimated distraction group. Mechanical complications occurred in 10/39 patients, five at each center. In the linear mixed effects model, we found that achieved lengthening increased with number of instrumented levels; however, there was no significant difference between the two centers.
Conclusions: In two comparable and consecutive cohorts we found no difference in achieved lengthening between distraction-to-stall and estimated distraction lengthening principles.
Ari Demirel, Peter Heide Pedersen, Søren Peter Eiskjær
Orthopaedics Department, Aalborg University Hospital; Orthopaedics Department, Aalborg University Hospital; Orthopaedics Department, Aalborg University Hospital
Background: During the course of treatment for adult idiopathic scoliosis (AIS), patients are subjected to repeated radiological exposure. Only a few studies have evaluated the total absorbed radiation dose during follow-up for scoliosis. To the best of our knowledge, this is the first study to evaluate total radiation dose exposure from all modalities for a cohort of AIS patients.
Purpose / Aim of Study: The aim of this study was to determine the radiation exposure of AIS patients and to compare follow-up algorithms among different international spine centers.
Materials and Methods: A retrospective review on radiation exposure of patients treated for AIS. Inclusions: patients followed for AIS at our institution from 2013-2016 without neuromuscular disease. The O-arm cone-beam CT scanner was used for 3D navigation in all surgically managed patients, low dose protocols were used (70kVp, 80mAs). A survey asking for information on radiological algorithms and imaging frequencies was sent to a number of international spine centers.
Findings / Results: 61 patients were included, 19 were treated conservatively (M/F: 6/13) and 42 surgically (M/F: 11/31). Median follow up time for the conservative group was 8 (range 0-51) months and 37 (range 13-163) months for the surgical group. Median number of X-rays/EOS were; 2 (range 0-20)/ 2 (range 0-17) for the conservative group and 15 (range 2-57)/11(range 0-26) for the surgery group. Patients undergoing surgery received a median cumulative radiation dose of 10.31mSv (range 3.79-20.43) vs. a median dose of 1.09mSv (range 0.22-7.17) for those treated conservatively. Approximately 25% (39.04/161.82mSv) of total intraoperative radiation dose for all patients was a result of O- arm 2D fluoroscopy. The results of the questionnaire showed great variety of radiological follow-up algorithms among 8 spine centers without adherence to any of the published consensus statements.
Conclusions: Surgically treated patients were exposed to more, radiation dose than those treated conservatively, owing mainly to intraoperative 3D scans and a larger numbers of radiological follow-up examinations. Further awareness to reduce radiation exposure is warranted in order to decrease potential risk of future radiation-induced malignancy.
Orthopaedics Department, Aalborg University Hospital; Orthopaedics Department, Aalborg University Hospital; Orthopaedics Department, Aalborg University Hospital
Background: During the course of treatment for adult idiopathic scoliosis (AIS), patients are subjected to repeated radiological exposure. Only a few studies have evaluated the total absorbed radiation dose during follow-up for scoliosis. To the best of our knowledge, this is the first study to evaluate total radiation dose exposure from all modalities for a cohort of AIS patients.
Purpose / Aim of Study: The aim of this study was to determine the radiation exposure of AIS patients and to compare follow-up algorithms among different international spine centers.
Materials and Methods: A retrospective review on radiation exposure of patients treated for AIS. Inclusions: patients followed for AIS at our institution from 2013-2016 without neuromuscular disease. The O-arm cone-beam CT scanner was used for 3D navigation in all surgically managed patients, low dose protocols were used (70kVp, 80mAs). A survey asking for information on radiological algorithms and imaging frequencies was sent to a number of international spine centers.
Findings / Results: 61 patients were included, 19 were treated conservatively (M/F: 6/13) and 42 surgically (M/F: 11/31). Median follow up time for the conservative group was 8 (range 0-51) months and 37 (range 13-163) months for the surgical group. Median number of X-rays/EOS were; 2 (range 0-20)/ 2 (range 0-17) for the conservative group and 15 (range 2-57)/11(range 0-26) for the surgery group. Patients undergoing surgery received a median cumulative radiation dose of 10.31mSv (range 3.79-20.43) vs. a median dose of 1.09mSv (range 0.22-7.17) for those treated conservatively. Approximately 25% (39.04/161.82mSv) of total intraoperative radiation dose for all patients was a result of O- arm 2D fluoroscopy. The results of the questionnaire showed great variety of radiological follow-up algorithms among 8 spine centers without adherence to any of the published consensus statements.
Conclusions: Surgically treated patients were exposed to more, radiation dose than those treated conservatively, owing mainly to intraoperative 3D scans and a larger numbers of radiological follow-up examinations. Further awareness to reduce radiation exposure is warranted in order to decrease potential risk of future radiation-induced malignancy.
Tanvir Johanning Bari, Sven Karstensen, Mathias Dahl Sørensen, Martin Gehrchen, John Street, Benny Dahl
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Combined Neurosurgical and Orthopedic Spine Program, Vancouver General Hospital, University of British Columbia, Canada; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital & Baylor College of Medicine, TX, USA
Background: Revision surgery and mortality are serious complications to spine surgery. Previous studies of frequency have mainly been retrospective, and to our knowledge, next to none have employed competing risk survival analyses. In addition, assessment of predictors has focused on preoperative patient-characteristics. The effect of perioperative adverse events (AE) on long-term revision and mortality risk is not yet fully understood.
Purpose / Aim of Study: To determine the 2-year risk of revision surgery and mortality after complex spine surgery, and to assess if prospectively registered AEs could predict either outcome.
Materials and Methods: In 2013, we prospectively included all patients undergoing complex spine surgery at a single, tertiary institution. AEs were registered using the Spine Adverse Event Severity system. Patients were followed for a minimum of two years in regards to revision surgery and mortality. Incidences were estimated using competing risk survival analyses, and correlation between AEs and either outcome was assessed using proportional odds models.
Findings / Results: We included 679 adult and pediatric patients. Demographics, surgical data, AEs and any event of revision or mortality were registered for all. The overall, 2-year, cumulative incidence of all-cause revision was 19% (16-22%) and all-cause mortality was 15% (12-18%). Deformity surgery was the surgical category with highest incidence of revision surgery, and the highest incidence of mortality was seen in the tumor group. We found that a major intraoperative AE was associated to threefold increased odds of revision. Deep wound infection was associated to four-fold increased odds of mortality.
Conclusions: We report the cumulative incidences of revision surgery and mortality following complex spine surgery in a consecutive and prospective cohort of patients. The incidence of revision surgery was higher across most surgical categories compared to previous retrospective studies. In addition, prospectively registered AEs were correlated to increased odds of revision surgery and mortality. The results presented in this paper may serve at reference for future interventional studies and as a simple tool to perioperatively identify unforeseen, at-risk patients.
Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Spine Unit, Department of Orthopedic Surgery, Rigshospitalet, Copenhagen University Hospital; Combined Neurosurgical and Orthopedic Spine Program, Vancouver General Hospital, University of British Columbia, Canada; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital & Baylor College of Medicine, TX, USA
Background: Revision surgery and mortality are serious complications to spine surgery. Previous studies of frequency have mainly been retrospective, and to our knowledge, next to none have employed competing risk survival analyses. In addition, assessment of predictors has focused on preoperative patient-characteristics. The effect of perioperative adverse events (AE) on long-term revision and mortality risk is not yet fully understood.
Purpose / Aim of Study: To determine the 2-year risk of revision surgery and mortality after complex spine surgery, and to assess if prospectively registered AEs could predict either outcome.
Materials and Methods: In 2013, we prospectively included all patients undergoing complex spine surgery at a single, tertiary institution. AEs were registered using the Spine Adverse Event Severity system. Patients were followed for a minimum of two years in regards to revision surgery and mortality. Incidences were estimated using competing risk survival analyses, and correlation between AEs and either outcome was assessed using proportional odds models.
Findings / Results: We included 679 adult and pediatric patients. Demographics, surgical data, AEs and any event of revision or mortality were registered for all. The overall, 2-year, cumulative incidence of all-cause revision was 19% (16-22%) and all-cause mortality was 15% (12-18%). Deformity surgery was the surgical category with highest incidence of revision surgery, and the highest incidence of mortality was seen in the tumor group. We found that a major intraoperative AE was associated to threefold increased odds of revision. Deep wound infection was associated to four-fold increased odds of mortality.
Conclusions: We report the cumulative incidences of revision surgery and mortality following complex spine surgery in a consecutive and prospective cohort of patients. The incidence of revision surgery was higher across most surgical categories compared to previous retrospective studies. In addition, prospectively registered AEs were correlated to increased odds of revision surgery and mortality. The results presented in this paper may serve at reference for future interventional studies and as a simple tool to perioperatively identify unforeseen, at-risk patients.
Søren Ohrt-Nissen, Keith DK Luk, Dino Samartzis, Jason PY Cheung
Department of Orthopedic surgery, Spine Unit, Copenhagen University hospital, Rigshospitalet; Department of Orthopedics and Traumatology, The University of Hong Kong; Department of Orthopaedic Surgery, RUSH University Medical Center; Department of Orthopedics and Traumatology, The University of Hong Kong
Background: Selection of the lowest instrumented vertebra (LIV) in main thoracic adolescent idiopathic scoliosis (AIS) remains controversial. Most guidelines for LIV selection are based on standing x-rays as does not take into account the flexibility of the curve.
Purpose / Aim of Study: To assess the radiographic and functional outcome using a standardized flexibility-based fusion strategy and to determine whether fusing shorter than the last touched vertebrae (LTV) was a safe approach in flexible main thoracic AIS curves.
Materials and Methods: This was a prospective study of consecutive patients with AIS surgically treated with alternate-level pedicle screw instrumentation. Only patients with selective fusion of the main thoracic curve were included in the study. Fusion level selection was based on the fulcrum bending radiograph method. Preoperative, postoperative and two-year follow-up radiographs were assessed. Patients were grouped based on the position of the LIV as proximal to the LTV (proxLTV), at the LTV (atLTV), and distal to the LTV (distLTV). Any adding-on was determined and the refined 22-item Scoliosis Research Society questionnaire was obtained.
Findings / Results: A total of 109 patients were included in the study and 43 were in the proxLTV, 45 were in the atLTV and 21 in the distLTV groups. Preoperatively, distLTV group had greater lumbar Cobb angle, lumbar apical translation and less flexibility in the thoracic curve. At two-year follow-up, the groups did not differ in thoracic curve correction but the distLTV had larger lumbar Cobb angle, more apical translation and worse coronal balance. Distal adding-on was most common in the proxLTV group (26%). Adding-on was only associated with younger patients at the time of surgery but not with any radiographic parameter. No differences in SRS-22r scores were observed between groups.
Conclusions: Proximal fusion carries the risk of adding-on but leaving unfused segments in the lower spine increases the potential for compensatory mechanisms to improve spinal and truncal balance. In mature patients with a flexible main thoracic curve, surgeons may consider fusion at or cranial to the LTV.
Department of Orthopedic surgery, Spine Unit, Copenhagen University hospital, Rigshospitalet; Department of Orthopedics and Traumatology, The University of Hong Kong; Department of Orthopaedic Surgery, RUSH University Medical Center; Department of Orthopedics and Traumatology, The University of Hong Kong
Background: Selection of the lowest instrumented vertebra (LIV) in main thoracic adolescent idiopathic scoliosis (AIS) remains controversial. Most guidelines for LIV selection are based on standing x-rays as does not take into account the flexibility of the curve.
Purpose / Aim of Study: To assess the radiographic and functional outcome using a standardized flexibility-based fusion strategy and to determine whether fusing shorter than the last touched vertebrae (LTV) was a safe approach in flexible main thoracic AIS curves.
Materials and Methods: This was a prospective study of consecutive patients with AIS surgically treated with alternate-level pedicle screw instrumentation. Only patients with selective fusion of the main thoracic curve were included in the study. Fusion level selection was based on the fulcrum bending radiograph method. Preoperative, postoperative and two-year follow-up radiographs were assessed. Patients were grouped based on the position of the LIV as proximal to the LTV (proxLTV), at the LTV (atLTV), and distal to the LTV (distLTV). Any adding-on was determined and the refined 22-item Scoliosis Research Society questionnaire was obtained.
Findings / Results: A total of 109 patients were included in the study and 43 were in the proxLTV, 45 were in the atLTV and 21 in the distLTV groups. Preoperatively, distLTV group had greater lumbar Cobb angle, lumbar apical translation and less flexibility in the thoracic curve. At two-year follow-up, the groups did not differ in thoracic curve correction but the distLTV had larger lumbar Cobb angle, more apical translation and worse coronal balance. Distal adding-on was most common in the proxLTV group (26%). Adding-on was only associated with younger patients at the time of surgery but not with any radiographic parameter. No differences in SRS-22r scores were observed between groups.
Conclusions: Proximal fusion carries the risk of adding-on but leaving unfused segments in the lower spine increases the potential for compensatory mechanisms to improve spinal and truncal balance. In mature patients with a flexible main thoracic curve, surgeons may consider fusion at or cranial to the LTV.