Spine
Kristian Høy, Kamilla Troung, Mads Henriksen, Thomas Andersen
Department of Orthopedics, Aarhus University Hospital, Denmark; Department of Neurosurgery, Aarhus University Hospital, Denmark; Department of Radiology, Aarhus University Hospital, Denmark; Orthopedic Department, Rigshospitalet University of Copenhagen, denmark
Background: Restoration of lumbar lordosis in lumbar spine surgery is thought to be associated with better postoperative outcomes. Various inter-body fusion techniques can theoretical help to change and correct sagittal balance. Pelvic plays a central role in sagittal balance. The Three key pelvic parameters are pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). The last 2 can change due to compensatory mechanism. Decrease in SS is posed to increase risk of adjacent segment degeneration (ASD)
Purpose / Aim of Study: To assess radiographic signs of degenerative changes and compensatory mechanisms after lumbar fusion at 10 year follow-up and their relation to outcome comparing posterolateral instrumented fusion (PLF) to Transforaminal interbody lumbar fusion (TLIF) in a RCT
Materials and Methods: 100 pat. enrolled in a RCT between TLIF and PLF had standing lumbar radiographs analyzed with respect to olisthesis, lordotic angle at adjacent level (AL) and differences in SS. SS was determined by PI = PT + SS. Clinical outcome was measured by Owestry disability index (ODI) and SF-36 Physical Function (PF), Bodily pain (BP) and Physical Component Summary(PCS). Data was analyzed using STATA
Findings / Results: There was no difference in development of olisthesis at the (AL) between the two groups at 10 year follow-up (p=0.43). Lordotic angle of the adjacent disc decreased with 5 or more degrees in 6 patients in the TLIF group and 3 in the PLF group. Three pats in the TLIF group and 4 in the PLF group had an increase in lordotic angle at the adjacent disc, the remainders were unchanged (p=0.58). Five pat. in the TLIF group and 7 in the PLF groups had a decrease in SS of 5 degrees or more (p=0.51).There was no difference in ODI score nor PF, BS & PCS at 10 year follow-up between those who developed changes in adjacent disc angle and those who remained unchanged (p=0.49, p=0.20, p=0.94 p=0.65). The same held true for changes in SS (p=0.46, p=0.49, p=0.39, p= 0.58)
Conclusions: No difference between the two fusion methods with respect to degenerative changes visible on radiographs at 10 years follow-up. Signs suggesting development in compensatory mechanisms (SS) was not associated with poorer clinical outcome
Department of Orthopedics, Aarhus University Hospital, Denmark; Department of Neurosurgery, Aarhus University Hospital, Denmark; Department of Radiology, Aarhus University Hospital, Denmark; Orthopedic Department, Rigshospitalet University of Copenhagen, denmark
Background: Restoration of lumbar lordosis in lumbar spine surgery is thought to be associated with better postoperative outcomes. Various inter-body fusion techniques can theoretical help to change and correct sagittal balance. Pelvic plays a central role in sagittal balance. The Three key pelvic parameters are pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). The last 2 can change due to compensatory mechanism. Decrease in SS is posed to increase risk of adjacent segment degeneration (ASD)
Purpose / Aim of Study: To assess radiographic signs of degenerative changes and compensatory mechanisms after lumbar fusion at 10 year follow-up and their relation to outcome comparing posterolateral instrumented fusion (PLF) to Transforaminal interbody lumbar fusion (TLIF) in a RCT
Materials and Methods: 100 pat. enrolled in a RCT between TLIF and PLF had standing lumbar radiographs analyzed with respect to olisthesis, lordotic angle at adjacent level (AL) and differences in SS. SS was determined by PI = PT + SS. Clinical outcome was measured by Owestry disability index (ODI) and SF-36 Physical Function (PF), Bodily pain (BP) and Physical Component Summary(PCS). Data was analyzed using STATA
Findings / Results: There was no difference in development of olisthesis at the (AL) between the two groups at 10 year follow-up (p=0.43). Lordotic angle of the adjacent disc decreased with 5 or more degrees in 6 patients in the TLIF group and 3 in the PLF group. Three pats in the TLIF group and 4 in the PLF group had an increase in lordotic angle at the adjacent disc, the remainders were unchanged (p=0.58). Five pat. in the TLIF group and 7 in the PLF groups had a decrease in SS of 5 degrees or more (p=0.51).There was no difference in ODI score nor PF, BS & PCS at 10 year follow-up between those who developed changes in adjacent disc angle and those who remained unchanged (p=0.49, p=0.20, p=0.94 p=0.65). The same held true for changes in SS (p=0.46, p=0.49, p=0.39, p= 0.58)
Conclusions: No difference between the two fusion methods with respect to degenerative changes visible on radiographs at 10 years follow-up. Signs suggesting development in compensatory mechanisms (SS) was not associated with poorer clinical outcome
Peter Muhareb Udby, Leah Carreon, Mikkel Østerheden Andersen, Stig Brorson, Søren Ohrt-Nissen, Rune Paulsen, Andresen Andreas, Christian Støttrup, Tom Bendix
Spine Unit, Zealand University hospital; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; CEBO, Zealand University hospital; Spine Unit, Rigshospitalet; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; VRR, Rigshospitalet
Background: Previous studies have failed to show a clinically significant association between Modic changes (MCs) and patient-reported outcomes (PRO’s) after discectomy.
Purpose / Aim of Study: To assess whether Modic Changes (MCs) are associated with health-related quality of life, long- term physical disability, back- or leg pain after discectomy.
Materials and Methods: Data from the Danish National Spine Registry on patients undergoing first-time lumbar discectomy at a single institution from 2014-17 with an accessible preoperative lumbar MRI, complete pre-operative and two-year follow-up questionnaires were obtained, n=620. Patients were stratified based on the presence (+MC) or absence (-MC) of MCs on the preoperative MRI.
Findings / Results: Of 620 patients included, MCs were present in 270 patients (47%). Of these, MC type 1 (MC-1) was present in 70 (25%) and MC type 2 (MC-2) in 210 (75%) patients. Preoperative data for ODI, EQ-5D, VAS-BP, and VAS-LP were comparable for the +MC and -MC groups. Both groups had a statistically significant improvement in PRO’s from baseline compared to two-year follow-up (p<0.001). At two-year follow-up, both groups had improved with no significant difference between them in regards to ODI (15.5 vs. 17.2, p=0.208); EQ-5D (0.75 vs. 0.72, p=0.167); VAS-BP (27.1 vs. 28.3, p=0.617); VAS-LP (26.8 vs. 25.0, p=0.446) and patient satisfaction (74% vs. 76%, p=0.878).
Conclusions: MCs were not found to be associated with health- related quality of life, disability, back- or leg pain or patient satisfaction two years after discectomy.
Spine Unit, Zealand University hospital; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; CEBO, Zealand University hospital; Spine Unit, Rigshospitalet; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; Spine Unit, Middelfart Hospital; VRR, Rigshospitalet
Background: Previous studies have failed to show a clinically significant association between Modic changes (MCs) and patient-reported outcomes (PRO’s) after discectomy.
Purpose / Aim of Study: To assess whether Modic Changes (MCs) are associated with health-related quality of life, long- term physical disability, back- or leg pain after discectomy.
Materials and Methods: Data from the Danish National Spine Registry on patients undergoing first-time lumbar discectomy at a single institution from 2014-17 with an accessible preoperative lumbar MRI, complete pre-operative and two-year follow-up questionnaires were obtained, n=620. Patients were stratified based on the presence (+MC) or absence (-MC) of MCs on the preoperative MRI.
Findings / Results: Of 620 patients included, MCs were present in 270 patients (47%). Of these, MC type 1 (MC-1) was present in 70 (25%) and MC type 2 (MC-2) in 210 (75%) patients. Preoperative data for ODI, EQ-5D, VAS-BP, and VAS-LP were comparable for the +MC and -MC groups. Both groups had a statistically significant improvement in PRO’s from baseline compared to two-year follow-up (p<0.001). At two-year follow-up, both groups had improved with no significant difference between them in regards to ODI (15.5 vs. 17.2, p=0.208); EQ-5D (0.75 vs. 0.72, p=0.167); VAS-BP (27.1 vs. 28.3, p=0.617); VAS-LP (26.8 vs. 25.0, p=0.446) and patient satisfaction (74% vs. 76%, p=0.878).
Conclusions: MCs were not found to be associated with health- related quality of life, disability, back- or leg pain or patient satisfaction two years after discectomy.
Jamal Bech Bouknaitir, Leah Y. Carreon, Stig Brorson, Mikkel Østerheden Andersen
Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark; Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark
Background: Patients with lumbar spinal stenosis present with low back pain, numbness and pain in the legs and gait difficulties due to neurogenic claudication. Patients often walk in a stooped posture to increase the spinal canal diameter by stretching out the ligamentum flavum. This stooped posture leads to a positive sagittal balance. After decompressive surgery, patients may walk in a less stooped manner, improving their sagittal balance, which may lead to less back pain and improved patient reported outcomes.
Purpose / Aim of Study: To determine if sagittal balance will improve in patients with spinal stenosis after decompression alone
Materials and Methods: This study compares pre-operative and 6-month post-operative full-length 36" standing lateral and posterior-anterior x-rays and one year Oswestry Disability Index (ODI), Visual analogue scale (VAS)- leg and back pain, in patients undergoing decompression alone without fusion for central or combined central and lateral stenosis, in patients 60 years and older from March 2016 until September 2017. The following radiographic parameters were measured Coronal Cobb Angle (COBB), Pelvic Incidence (PI), Sagittal Vertical Axis (SVA), Lumbar Lordosis (LL), Pelvic Tilt (PT), Pelvic Incidence- Lumbar Lordosis ratio (PI-LL) and Sacral Slope (SS).
Findings / Results: Forty-five patients (24 males and 21 females) were included. Patients had symptoms for more than 3 months at the time of surgery. Most patients were operated with a bilateral laminectomy over two levels. Sagittal balance showed a statistical significant change in SVA from 65.0mm to 48.6mm (p=0.009) and PI-LL mismatch 7.80 to 4.24 (p= 0.005). A small to moderate association was found between SVA and ODI both preoperatively (r=0.54, p= 0.001) and postoperatively (r=0.51, p= 0.001) and preoperative VAS-leg/back pain (r=0.60, p=0.001)/(r=0.42,p=0.009).
Conclusions: There is a statistically significant improvement in sagittal balance in patients undergoing decompression alone for lumbar spinal stenosis. Associations between the SVA and ODI and VAS- leg/back pain indicate that improvements in sagittal balance contribute to improvements in patient reported outcomes.
Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark; Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark
Background: Patients with lumbar spinal stenosis present with low back pain, numbness and pain in the legs and gait difficulties due to neurogenic claudication. Patients often walk in a stooped posture to increase the spinal canal diameter by stretching out the ligamentum flavum. This stooped posture leads to a positive sagittal balance. After decompressive surgery, patients may walk in a less stooped manner, improving their sagittal balance, which may lead to less back pain and improved patient reported outcomes.
Purpose / Aim of Study: To determine if sagittal balance will improve in patients with spinal stenosis after decompression alone
Materials and Methods: This study compares pre-operative and 6-month post-operative full-length 36" standing lateral and posterior-anterior x-rays and one year Oswestry Disability Index (ODI), Visual analogue scale (VAS)- leg and back pain, in patients undergoing decompression alone without fusion for central or combined central and lateral stenosis, in patients 60 years and older from March 2016 until September 2017. The following radiographic parameters were measured Coronal Cobb Angle (COBB), Pelvic Incidence (PI), Sagittal Vertical Axis (SVA), Lumbar Lordosis (LL), Pelvic Tilt (PT), Pelvic Incidence- Lumbar Lordosis ratio (PI-LL) and Sacral Slope (SS).
Findings / Results: Forty-five patients (24 males and 21 females) were included. Patients had symptoms for more than 3 months at the time of surgery. Most patients were operated with a bilateral laminectomy over two levels. Sagittal balance showed a statistical significant change in SVA from 65.0mm to 48.6mm (p=0.009) and PI-LL mismatch 7.80 to 4.24 (p= 0.005). A small to moderate association was found between SVA and ODI both preoperatively (r=0.54, p= 0.001) and postoperatively (r=0.51, p= 0.001) and preoperative VAS-leg/back pain (r=0.60, p=0.001)/(r=0.42,p=0.009).
Conclusions: There is a statistically significant improvement in sagittal balance in patients undergoing decompression alone for lumbar spinal stenosis. Associations between the SVA and ODI and VAS- leg/back pain indicate that improvements in sagittal balance contribute to improvements in patient reported outcomes.
Simon Thorbjørn Sørensen, Maha Sakr Alameddine, Jonna Skov Madsen, Leah Carreon, Mikkel Østerheden Andersen, Ane Simony
Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Department of Clinical Biochemistry and Immunology, Sygehus Lillebælt; Department of Clinical Biochemistry and Immunology, Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt
Background: Concerns have been raised regarding persistent levels of serum metal ions in patients with spinal instrumentation, there are only a few studies published on the topic
Purpose / Aim of Study: Do patients with Adolescent Idiopathic Scoliosis (AIS) treated with Harrington Rod Instrumentation have higher levels of serum metal ions compared to patients treated with Bracing?
Materials and Methods: AIS patients treated with Boston brace (BB) or posterior spinal fusion with Harrington rod instrumentation (HR) from 1983 to 1990 were requested to return to clinic. One hundred fifty-nine (73%) of 219 patients were available for follow-up of whom 115 agreed to have a blood draw.
Findings / Results: The proportion of patients who agreed to have a blood draw were similar in the BB (48 of 100, 48%) and HR (67 of 112, 60%, p=0.085) groups. None of the surgical patients had their implants removed. Mean age at follow-up (BB: 43.2yrs vs HR: 43.5yrs, p=0.566) and mean length of follow up (BB: 26.5yrs vs HR: 24.5yrs). Mean Chromium serum levels were similar between the BB (2.71nmol/L) and the HR (2.94nmol/L, p=0.827). Mean Cobalt serum levels were also similar between the BB (2.62nmol/L) and the HR (2.75nmol/L, p=0.200).
Conclusions: Serum metal ions were similar in AIS patients treated with bracing or Harrington Rod instrumentation 25 years after initiation of treatment.
Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Department of Clinical Biochemistry and Immunology, Sygehus Lillebælt; Department of Clinical Biochemistry and Immunology, Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt; Center for Spine Surgery and Research, Rygcenter Syddanmark - Sygehus Lillebælt
Background: Concerns have been raised regarding persistent levels of serum metal ions in patients with spinal instrumentation, there are only a few studies published on the topic
Purpose / Aim of Study: Do patients with Adolescent Idiopathic Scoliosis (AIS) treated with Harrington Rod Instrumentation have higher levels of serum metal ions compared to patients treated with Bracing?
Materials and Methods: AIS patients treated with Boston brace (BB) or posterior spinal fusion with Harrington rod instrumentation (HR) from 1983 to 1990 were requested to return to clinic. One hundred fifty-nine (73%) of 219 patients were available for follow-up of whom 115 agreed to have a blood draw.
Findings / Results: The proportion of patients who agreed to have a blood draw were similar in the BB (48 of 100, 48%) and HR (67 of 112, 60%, p=0.085) groups. None of the surgical patients had their implants removed. Mean age at follow-up (BB: 43.2yrs vs HR: 43.5yrs, p=0.566) and mean length of follow up (BB: 26.5yrs vs HR: 24.5yrs). Mean Chromium serum levels were similar between the BB (2.71nmol/L) and the HR (2.94nmol/L, p=0.827). Mean Cobalt serum levels were also similar between the BB (2.62nmol/L) and the HR (2.75nmol/L, p=0.200).
Conclusions: Serum metal ions were similar in AIS patients treated with bracing or Harrington Rod instrumentation 25 years after initiation of treatment.
Jamal Bech Bouknaitir, Leah Y. Carreon, Stig Brorson, Mikkel Østerheden Andersen
Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark; Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark
Background: The Zurich Claudication Questionnaire (ZCQ), also known as the Swiss Spinal Stenosis Measure or the Brigham spinal stenosis questionnaire was developed in 1996 by Gerald Stucki et al. The ZCQ was designed specifically to evaluate physical function and to assess quality of life in patients with LSS. Since its introduction, the ZCQ has become one of the primary outcome measures when reporting on treatment results in patients with spinal stenosis. The ZCQ is a self-administered Patient Reported Outcome Measure (PROM) measuring symptom severity, physical function and patient satisfaction in patients with LSS. The questionnaire has not yet been culturally adapted and translated into Danish.
Purpose / Aim of Study: was to translate and validate the Zurich Claudication Questionnaire ZCQ into a Danish version of the disease specific patient reported outcome measure PROM for patients with Lumbar spinal stenosis LSS, which assesses Symptom severity, Physical function and satisfaction after surgery.
Materials and Methods: Translation into a Danish version of the original questionnaire by back and forward translating the questionnaire and finally transforming a prefinal test version into a final and cross cultural adapted version. Validation was performed as a cohort study assessing floor-ceiling effects, Internal consistency, test-retest reliability, criterion validity, discriminant validity and responsiveness to change.
Findings / Results: Seventy-five patients were consecutively included in the study, fifty-three healthy controls were matched. Floor effect was seen in the postoperative data. Internal consistency, Cronbach alpha was good to excellent. Substantial test-retest reliability was found using Cohen’s weighted kappa. The Danish ZCQ showed moderate to strong association with similar domains of ODI, SF-36, EQ-5D, VAS-leg and VAS- back. The questionnaire showed significant responsiveness to change and a significant discriminant validity between LSS patients and healthy controls.
Conclusions: This study shows the Danish translation of the original Zurich claudication questionnaire to be well understood by Danish patients. The Danish version is furthermore a reliable and valid questionnaire, which is responsive to change.
Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark; Spine Unit, Department of Orthopedic Surgery, Zealand University Hospital, Køge, Denmark; Spine Surgery and Research, Spine Center of Southern Denmark – part of Lillebaelt Hospital, Denmark
Background: The Zurich Claudication Questionnaire (ZCQ), also known as the Swiss Spinal Stenosis Measure or the Brigham spinal stenosis questionnaire was developed in 1996 by Gerald Stucki et al. The ZCQ was designed specifically to evaluate physical function and to assess quality of life in patients with LSS. Since its introduction, the ZCQ has become one of the primary outcome measures when reporting on treatment results in patients with spinal stenosis. The ZCQ is a self-administered Patient Reported Outcome Measure (PROM) measuring symptom severity, physical function and patient satisfaction in patients with LSS. The questionnaire has not yet been culturally adapted and translated into Danish.
Purpose / Aim of Study: was to translate and validate the Zurich Claudication Questionnaire ZCQ into a Danish version of the disease specific patient reported outcome measure PROM for patients with Lumbar spinal stenosis LSS, which assesses Symptom severity, Physical function and satisfaction after surgery.
Materials and Methods: Translation into a Danish version of the original questionnaire by back and forward translating the questionnaire and finally transforming a prefinal test version into a final and cross cultural adapted version. Validation was performed as a cohort study assessing floor-ceiling effects, Internal consistency, test-retest reliability, criterion validity, discriminant validity and responsiveness to change.
Findings / Results: Seventy-five patients were consecutively included in the study, fifty-three healthy controls were matched. Floor effect was seen in the postoperative data. Internal consistency, Cronbach alpha was good to excellent. Substantial test-retest reliability was found using Cohen’s weighted kappa. The Danish ZCQ showed moderate to strong association with similar domains of ODI, SF-36, EQ-5D, VAS-leg and VAS- back. The questionnaire showed significant responsiveness to change and a significant discriminant validity between LSS patients and healthy controls.
Conclusions: This study shows the Danish translation of the original Zurich claudication questionnaire to be well understood by Danish patients. The Danish version is furthermore a reliable and valid questionnaire, which is responsive to change.
Sidsel Fruergaard, Søren Ohrt-Nissen, Frederik Taylor Pitter, Kristian Høy, Martin Lindberg-Larsen, Søren Eiskjær, 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; Spine Unit, Department of Orthopedic Surgery,, Aarhus University Hospital; Orthopaedic research unit, Department of Orthopedic Surgery and Traumatology, Department of Clinical Research,, Odense University Hospital, University of Southern Denmark,; Department of Orthopedic Surgery, Aalborg University Hospital; Department of Orthopedic Surgery, Texas Children’s Hospital and Baylor College of Medicine; Spine Unit, Department of Orthopedic Surgery, , Rigshospitalet, Copenhagen University Hospital
Background: Revision risk after pediatric spine surgery is not well established but varies among patients with different deformity etiologies.
Purpose / Aim of Study: To report on the two-year revision risk following surgery for primary pediatric spine deformity in a nationwide cohort. Secondarily, to evaluate potential risk factors for revision surgery and describe reasons for revision.
Materials and Methods: All patients ≤ 21 years of age undergoing spine deformity surgery in Denmark in 2006–2015 were identified by procedure and diagnosis code in the Danish National Patient Registry (DNPR). From DNPR, data on revision within two years were retrieved. Patients were categorized in six groups according to etiology. Medical records were reviewed for reason for revision. Identification of risk factors for revision was assessed with multiple logistic regression analyses and included the variables; age, etiology, sex and growing-rod treatment.
Findings / Results: Of 1310 surgically treated pediatric patients, 9 % were revised within 2 years and 1.5 % were revised more than once. Median time to revision was 203 (IQR 35-485) days. Patients were categorized according to etiology; idiopathic scoliosis (53%), congenital/structural scoliosis (9%), neuromuscular scoliosis (23%), syndromic scoliosis (3%), spondylolisthesis (7%) and Scheuermann kyphosis (5%). Independent, significant risk factors for revision were growing rods (OR = 4.4, 95% CI 2.2–8.8) and etiologies of (with idiopathic scoliosis as reference) congenital (OR=2.7, 95% CI 1.3-5.4), neuromuscular (OR = 1.9, 95% CI 1.1–3.2), spondylolisthesis (OR = 3.6, 95% CI 1.9–7.0) and Scheuermann kyphosis (OR = 3.8, 95% CI 1.8–8.2). The most common reason for revision was implant failure (33%) followed by residual deformity and/or curve progression (16%).
Conclusions: In this nationwide study, the two-year revision risk after pediatric spine deformity surgery was 9%. Risk factors for revision were etiology of congenital deformity, neuromuscular deformity, spondylolisthesis, Scheuermann kyphosis and patients with growing rods. The most common reason for revision was implant failure.
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,, Aarhus University Hospital; Orthopaedic research unit, Department of Orthopedic Surgery and Traumatology, Department of Clinical Research,, Odense University Hospital, University of Southern Denmark,; Department of Orthopedic Surgery, Aalborg University Hospital; Department of Orthopedic Surgery, Texas Children’s Hospital and Baylor College of Medicine; Spine Unit, Department of Orthopedic Surgery, , Rigshospitalet, Copenhagen University Hospital
Background: Revision risk after pediatric spine surgery is not well established but varies among patients with different deformity etiologies.
Purpose / Aim of Study: To report on the two-year revision risk following surgery for primary pediatric spine deformity in a nationwide cohort. Secondarily, to evaluate potential risk factors for revision surgery and describe reasons for revision.
Materials and Methods: All patients ≤ 21 years of age undergoing spine deformity surgery in Denmark in 2006–2015 were identified by procedure and diagnosis code in the Danish National Patient Registry (DNPR). From DNPR, data on revision within two years were retrieved. Patients were categorized in six groups according to etiology. Medical records were reviewed for reason for revision. Identification of risk factors for revision was assessed with multiple logistic regression analyses and included the variables; age, etiology, sex and growing-rod treatment.
Findings / Results: Of 1310 surgically treated pediatric patients, 9 % were revised within 2 years and 1.5 % were revised more than once. Median time to revision was 203 (IQR 35-485) days. Patients were categorized according to etiology; idiopathic scoliosis (53%), congenital/structural scoliosis (9%), neuromuscular scoliosis (23%), syndromic scoliosis (3%), spondylolisthesis (7%) and Scheuermann kyphosis (5%). Independent, significant risk factors for revision were growing rods (OR = 4.4, 95% CI 2.2–8.8) and etiologies of (with idiopathic scoliosis as reference) congenital (OR=2.7, 95% CI 1.3-5.4), neuromuscular (OR = 1.9, 95% CI 1.1–3.2), spondylolisthesis (OR = 3.6, 95% CI 1.9–7.0) and Scheuermann kyphosis (OR = 3.8, 95% CI 1.8–8.2). The most common reason for revision was implant failure (33%) followed by residual deformity and/or curve progression (16%).
Conclusions: In this nationwide study, the two-year revision risk after pediatric spine deformity surgery was 9%. Risk factors for revision were etiology of congenital deformity, neuromuscular deformity, spondylolisthesis, Scheuermann kyphosis and patients with growing rods. The most common reason for revision was implant failure.