Anteroposterior Fusion Research Articles

Comparison of Complication Rates Between Transforaminal Interbody Fusion and Anteroposterior Fusion for One- or Two-Level Degenerative Lumbar Spine Surgery: A Propensity Score Matched Analysis.

Introduction Although transforaminal interbody fusion (TLIF) and anterior lumbar interbody fusion (ALIF) combined with posterior fusion (AP) have similar fusion rates, it is unclear if choice of approach has an impact on post-operative complications. Research question Is the incidence of residual leg and/or back pain requiring additional treatment after one- or two-level TLIF and AP similar? Material and methods Adult patients who underwent one- or two-level TLIF or AP for degenerative pathology were identified and matched using age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA), insurance status, smoking status, revision and number of levels fused. The incidence of radicular leg and back pain requiring emergency department visit/readmission or same level surgical intervention was compared between the two groups. Results Of the 319 TLIF and 288 AP cases, 119 cases in each cohort were matched. TLIF patients had shorter operative times (203 min vs 258 min, P<0.001) and hospital stays than the AP patients (3.76 days vs 4.98 days, P<0.001). The incidence of residual leg pain (7 vs 5, P=0.769) and back pain (13 vs 15, P=0.841) was similar between the two groups. Except for constipation, which was more common in the AP group, the incidence of complications was similar between the two groups. Conclusions Patients undergoing one- or two-level TLIF showed shorter operative time and hospital stay compared with those undergoing AP. The incidence of leg radiculopathy and back pain was similar between the two groups. Surgeons should consider these findings as part of the decision-making process regarding which approach to use in patients requiring a lumbar interbody fusion.

A comparative cohort study of surgical approaches for adult spinal deformity at a minimum 2-year follow-up.

This study was a retrospective multi-center comparative cohort study. A retrospective institutional database of operative adult spinal deformity patients was utilized. All fusions > 5 vertebral levels and including the sacrum/pelvis were eligible for inclusion. Revisions, 3 column osteotomies, and patients with < 2-year clinical follow-up were excluded. Patients were separated into 3 groups based on surgical approach: 1) posterior spinal fusion without interbody (PSF), 2) PSF with interbody (PSF-IB), and 3) anteroposterior (AP) fusion (anterior lumbar interbody fusion or lateral lumbar interbody fusion with posterior screw fixation). Intraoperative, radiographic, and clinical outcomes, as well as complications, were compared between groups with ANOVA and χ2 tests. One-hundred and thirty-eight patients were included for study (PSF, n = 37; PSF-IB, n = 44; AP, n = 57). Intraoperatively, estimated blood loss was similar between groups (p = 0.171). However, the AP group had longer operative times (547.5min) compared to PSF (385.1) and PSF-IB (370.7) (p < 0.001). Additionally, fusion length was shorter in PSF-IB (11.4) compared to AP (13.6) and PSF (12.9) (p = 0.004). There were no differences between the groups in terms of change in alignment from preoperative to 2years postoperative. There were no differences in clinical outcomes. While postoperative complications were largely similar between groups, operative complications were higher in the AP group (31.6%) compared to the PSF (5.4%) and PSF-IB (9.1) groups (p < 0.001). While there were differences in intraoperative outcomes (operative time and fusion length), there were no differences in postoperative clinical or radiographic outcomes. AP fusion was associated with a higher rate of operative complications.

Functional and Radiological Outcomes of All-Posterior Surgical Correction of Dystrophic Curves in Patients with Neurofibromatosis Type 1.

A retrospective cohort study. To determine outcomes following all-posterior surgery using computed tomography navigation, hybrid stabilization, and multiple anchor point techniques in patients with neurofibromatosis type 1 (NF-1) and dystrophic scoliosis. Previous studies favored antero-posterior fusion as the most reliable method; however, approaching the spine anteriorly was fraught with significant complications. With the advent of computer assisted navigation and multiple anchor point method, posterior only approach is reporting successful outcomes. This study included patients who underwent all-posterior surgical deformity correction for dystrophic NF-1 curves. Coronal and sagittal Cobbs angles, apical rotation, and the presence of dystrophic features were evaluated before surgery. Postoperatively, sagittal, coronal, and axial correction, implant position, and implant densities were evaluated. The decline in curve correction and implant-related complications were evaluated at follow-up. Clinical outcomes were evaluated using the Scoliosis Research Society-22 revised index. This study involved 50 patients with a mean age of 13.6 years and a mean follow-up duration of 5.52 years. With a mean coronal flexibility of 18.7%, the mean apical vertebral rotation (AVR), preoperative coronal Cobb angle, and sagittal kyphosis were 27.4°, 64.01°, and 47.70°, respectively. The postoperative mean coronal Cobb angle was 30.17° (p <0.05), and the sagittal kyphosis angle was 25.4° (p <0.05). The average AVR correction rate was 41.3%. The correction remained significant at the final mean follow-up, with a coronal Cobb angle of 34.14° and sagittal kyphosis of 25.02° (p <0.05). The average implant density was 1.41, with 46% of patients having a high implant density (HID). The HID had a markedly higher mean curve correction (29.30° vs. 38.05°, p <0.05) and a lower mean loss of correction (5.7° vs. 3.8°, p <0.05). Utilizing computer-assisted navigation, hybrid instrumentation, and multiple anchor point technique and attaining high implant densities, this study demonstrates successful outcomes following posterior-only surgical correction of dystrophic scoliosis in patients with NF-1.

Rate and risk factors for pediatric cervical spine fusion pseudarthrosis: opportunity for improvement

PurposeAlthough the pediatric population typically has a high union rate, the cervical spine has a reputation for frequent pseduarthrosis, as high as 38% in some prior series. Our purpose was to examine the rate and risk factors for pseudarthrosis in pediatric cervical spine fusions.MethodsRetrospective review of all patients with ≥ 2 years follow-up undergoing cervical spinal fusion between January 2004 and December 2019 at a tertiary pediatric hospital. Pseudarthrosis was defined as an absence of radiographic union as assessed by the attending surgeon for which revision surgery was performed.Results64 patients (mean age: 8.4 ± 4.7 years) met inclusion criteria. Mean follow-up was 63.3 ± 41.4 months (range: 24–187 months). 28 fusions (44%) included the occiput. 41 patients (64%) had instrumentation, while 23 patients (36%) had uninstrumented fusions. 48 (75%) patients had a halo for a mean of 97.6 ± 49.5 days. The incidence of pseudarthrosis was as follows: overall = 8/64 (12.5%); posterior fusion = 14.8% (8/54); anterior fusions = 0% (0/4); and anteroposterior fusions = 0% (0/6). The rate of pseudarthrosis was over 8 times higher in fusions involving the occiput (occipitocervical fusion: 25.0%; 7/28 vs. cervical alone: 2.8%; 1/36; p = 0.02). Although not statistically significant, the rate of pseudarthrosis was 3 times higher in uninstrumented fusions (21.7%; 5/23) than instrumented fusions (7.3%; 3/41) (p = 0.12). In patients with uninstrumented fusion to the occiput, pseudarthrosis rate was 35.7% (5/14), which was higher compared to those who did not (6.0%; 3/50) (p = 0.01). Incidence of pseudarthrosis was similar in patients who received autograft (13.0%; 7/54) compared to allograft alone (10.0%; 1/10) (p > 0.999).ConclusionsThe pseudarthrosis rate in pediatric cervical spine fusions remained high despite frequent use of halo immobilization and autograft. Patients with uninstrumented occipitocervical fusions are at particularly high risk with more than 1 in 3 developing a pseudarthrosis.Study designRetrospective, Comparative.Level of EvidenceIII.

Radiological Evaluation of Combined Anteroposterior Fusion with Vertebral Body Replacement Using a Minimally Invasive Lateral Approach for Osteoporotic Vertebral Fractures: Verification of Optimal Surgical Procedure.

The combined anteroposterior fusion with vertebral body replacement (VBR) using a wide footplate expandable cage with a minimally invasive lateral approach has been widely used for pseudoarthrosis after osteoporotic vertebral fractures. The purpose of this study is to evaluate the radiological results of combined anteroposterior surgery using VBR and to recommend the optimal procedure. Thirty-eight elderly patients were included in this study. The mean preoperative local kyphosis angle was 29.3°, and the mean correction loss angle was 6.3°. Cage subsidence was observed in ten patients (26.3%), and UIV or LIV fracture in twelve patients (31.6%). Patients with cage subsidence were compared to those without cage subsidence to determine the causal factors. The mean number of fixed vertebrae was 5.4 vertebrae with cage subsidence and 7.4 vertebrae without cage subsidence. In addition, to precisely clarify the optimal number of fixed vertebrae, those patients with two above–two below fixation were compared to those with less than two above–two below fixation, which revealed that the correction loss angle was significantly less in two above–two below fixation (p = 0.016). Based on these results, we recommend at least two above–two below fixation with VBR to minimize the correction loss angle and prevent cage subsidence.

Surgical Outcomes of Subaxial Cervical Fractures in Patients with Ankylosing Spinal Disorder.

To evaluate the patient groups with ankylosing spinal disorder (ASD) in terms of patients? characteristics, applied surgical approaches, and the outcomes. Between 2008-2019, 50 ASD patients (35?80 years) were operated on subaxial cervical fracture. The mean follow-up time was 48 months. According to the surgical approach, the patients were divided into three groups: patients who only underwent anterior fusion [AF], patients who only underwent posterior fusion [PF], and patients who underwent anteroposterior fusion [APF]. In this retrospective study, we examined the patients? files and outpatient checks to evaluate the history, operations, neurological results, and complications in cases. After undergoing respective surgical interventions, 1 of the 7 patients in the AF group (14%), 2 of the 18 patients in the PF group (18%), and 3 of the 25 patients in the APF group (12%) died. The postoperative American Spinal Injury Association scores were statistically better in all groups than in the preoperative scores. Among the surgical interventions, improvement in the APF group was significantly better than in other groups. Although there is a higher amount of surgery related complications in the APF group, the biomechanical and clinical results are better than the other two surgical interventions.

Fusi In Situ Posterior for Congenital Scoliosis with Wedge Hemivertebrae Using Single Rod and Pedicle Screw Instrumentation in Girl 2 Years Old: A Case Report

Background: Many spinal vertebral anoma­lies often occur, both scoliosis and kyfosis. In scoliosis, congenital abnormalities caused by hemivertebrae are the most common cause of abnormalities. The choice of treatment used can be either non-operative or operative. How­ever, non-operative treatment does not show satisfactory results to prevent the development of deformity. Operative treatment is an option that is considered to indicate more satisfying results. A variety of procedures such as in-situ posterior or with or without instrumentation anteroposterior fusions, combined anterior and poste­rior convex hemiepiphysiodesis and hemi­arthrodesis, and hemivertebral excision with fusion. Fusi In-situ posterior is a procedure option that is considered more beneficial for both surgeons and patients. This study aimed to evaluate the fusi in situ posterior for conge­nital scoliosis with wedge hemivertebrae using single rod and pedicle screw instrumentation in girl 2 year old. Case Presentation : Girl 2 year old with wedge hemivertebrae operated with fusion in situ posterior using single rod and pedicle screw instrumentation. Results: The operative treatment was per­formed on 2 hours operation time with amount of bleeding produced is 80 cc. There were no cranckshaft phenomena and no clinical and radological features suggestive of spinal ste­nosis. There were no major vascular or neuro­gical complications related to the pedicle screws. Then patient wore body jacket for limitation movement before fusion. Conclusion: Posterior situ fusion is perform­ed as convex fusion to avoid curve progression. Fusion in situ posterior using single rod and pedicle screw instrumentation. In congenital scoliosis is minimal blood loss, less traumatic, simple, safe and effective procedure. This study showed the early fusi in situ posterior of conge­nital scoliosis structural changes occur above or below can reduce fusion length, prevent curve progression and effectively achieve a more satisfactory correction without hazardous iatro­genic spinal stenosis, crankshaft phenomena, or neurological complications. Further research is needed to assess the progress of the outcome of surgery Keyword s : congenital scoliosis, wedge hemi­vertebrae, convex, fusi in situ posterior Correspondence: Pamudji Utomo. Department of Orthopaedic & Traumatology, Faculty of Medicine, Universitas Sebelas Maret/ Prof. Dr. R. Soeharso Ortho­pae­dic Hospital, Surakarta Indonesian Journal of Medicine (2020), 05(02): 125-130 https://doi.org/10.26911/theijmed.2020.05.02.05

Rapidly increasing incidence in scoliosis surgery over 14\xa0years in a nationwide sample

PurposeSevere scoliosis is primarily managed with surgery. This cohort study describes the incidence of surgically treated scoliosis among Swedish youth and young adults, stratified by age, sex, scoliosis type, and surgical approach and identifies changes in incidence rate and hospital length of stay (LOS), infections requiring re-surgery and mortality within 90 days.MethodsSwedish youth, 0–21 years, (n = 3062) with a diagnostic code for scoliosis and spine surgery between 2000 and 2013 were selected from the National Patient Register. Incidence was computed by comparing individuals with surgically treated scoliosis to the total at risk population. Linear regression models and Spearman correlation coefficients analyzed trends over time.ResultsOverall annual incidence per 100,000 individuals was 9.1 (5.9 males/12.5 females). Annual incidence increased over 14 years from 5.1 to 9.8; an average 4.6% per year (p < 0.001). Adolescent idiopathic scoliosis was most common (4.5 per 100,000; n = 1516) followed by neuromuscular 2.7 (n = 913) and congenital 0.7 (n = 236). Average LOS decreased among scoliosis types except infantile and neuromuscular scoliosis. Posterior fusion was the most common surgical approach (75%) followed by anterior (18%) and anteroposterior fusion (7%). Posterior fusions significantly increased with a resultant decrease in anterior and anteroposterior fusion over time. Individuals with neuromuscular scoliosis exhibited the highest mortality (n = 12; 1.3%) and (n = 59; 6%) of individuals with neuromuscular scoliosis and (n = 12; 15%) with scoliosis related to MMC required revision surgery due to post-op infection.ConclusionsSurgical management of scoliosis is increasing with a concurrent decrease in hospital LOS. Surgical management of neuromuscular scoliosis is associated with high 90-day post-operative infections and mortality rate.

Coronal Spinal Balance in Adult Spine Deformity Patients With Long Spinal Fusions

This study was a retrospective one. The objective of the study was to analyze the causes, prevalence of, and risk factors for coronal decompensation in long adult lumbar spinal instrumentation and fusion (from thoracic or upper lumbar spine) to L5 or S1. Coronal and sagittal decompensation after long fusions for spinal deformities can affect outcomes negatively. There is no study reporting the natural history of coronal spinal balance after long spinal fusions. A single-center retrospective review of data from 54 patients with spinal deformity was performed. Inclusion criteria were patients over 18 years with long fusions (>4 segments) to L5 or the pelvis who had full spine standing radiographs before surgery and up to 2-5 years postoperatively. Radiographic data included C7PL, magnitude of scoliotic curve, shoulder or pelvic asymmetry in the coronal plane, thoracic kyphosis, lumbar lordosis, and pelvic parameters (pelvic incidence, pelvic tilt, sacral slope). Coronal imbalance (CI) was considered if the C7PL was >4 cm lateral to the central sacral line, and sagittal imbalance (SI) was considered when the C7 plumbline was >4 cm anterior to the middle of the upper sacral plate. Paired t test, χ test, and repeated measures regression analysis using demographic data (age, sex, body mass index), operative (previous fusion, posterior only or anteroposterior fusion, iliac fixation or not, decompression or not, osteotomy or not) and postoperative (complications, use of bracing) data, and radiographic parameters (including SI) were performed. Patients showing CI equaled 11 (19.3%) preoperatively, remained 11 (19.3%) (4 of whom were new patients with CI) at 6 weeks postoperatively, and increased (P<0.001) to 18 (31.6%) (8 of them without initial CI) at 2-5 years follow-up. However, in terms of numeric distance of C7PL from the midsacrum, there was no statistically significant change (P>0.05) from preoperative to last follow-up. SI showed significant improvement (P<0.05) from preoperative to 6 weeks postoperative and no statistical significant change (P>0.05) from 6 weeks to 2-5 years postoperatively. Repeated measures regression analysis showed that the presence of osteoporosis and the combination of anterior approach surgery with a history of previous surgery were significant (P<0.05) factors predictive of changes in coronal balance. After surgical correction of spinal deformities, coronal spinal decompensation appears in an increased number of patients at last follow-up postoperatively but without significant differences in coronal plane C7PL during the postoperative period. Attention should be paid to patients with osteoporosis and those with a combination of previous same site posterior spine surgery and new anterior approach surgery for changes of coronal balance postoperatively.

Does Recombinant Human Bone Morphogenetic Protein-2 Use in Adult Spinal Deformity Increase Complications and Are Complications Associated With Location of rhBMP-2 Use? A Prospective, Multicenter Study of 279 Consecutive Patients

Multicenter, prospective analysis of consecutive patients with adult spinal deformity (ASD). Evaluate complications associated with recombinant human bone morphogenetic protein-2 (rhBMP-2) use in ASD. Off-label rhBMP-2 use is common; however, underreporting of rhBMP-2 associated complications has been recently scrutinized. Patients with ASD consecutively enrolled into a prospective, multicenter database were evaluated for type and timing of acute perioperative complications. age 18 years and older, ASD, spinal arthrodesis of more than 4 levels, and 3 or more months of follow-up. Patients were divided into those receiving rhBMP-2 (BMP) or no rhBMP-2 (NOBMP). BMP divided into location of use: posterior (PBMP), interbody (IBMP), and interbody + posterior spine (I + PBMP). Correlations between acute perioperative complications and rhBMP-2 use including total dose, dose/level, and location of use were evaluated. A total of 279 patients (mean age: 57 yr; mean spinal levels fused: 12.0; and mean follow-up: 28.8 mo) met inclusion criteria. BMP (n = 172; average posterior dose = 2.5 mg/level, average interbody dose = 5 mg/level) had similar age, smoking history, previous spine surgery, total spinal levels fused, estimated blood loss, and duration of hospital stay as NOBMP (n = 107; P > 0.05). BMP had greater Charlson Comorbidity Index (1.9 vs. 1.2), greater scoliosis (43° vs. 38°), longer operative time (488.2 vs. 414.6 min), more osteotomies per patient (4.0 vs. 1.6), and greater percentage of anteroposterior fusion (APSF; 20.9% vs. 8.4%) than NOBMP, respectively (P < 0.05). BMP had more total complications per patient (1.4 vs. 0.6) and more minor complications per patient (0.9 vs. 0.2) than NOBMP, respectively (P < 0.05). NOBMP had more complications requiring surgery per patient than BMP (0.3 vs. 0.2; P < 0.05). Major, neurological, wound, and infectious complications were similar for NOBMP, BMP, PBMP, IBMP, and I + PBMP (P > 0.05). Multivariate analysis demonstrated small to nonexistent correlations between rhBMP-2 use and complications. RhBMP-2 use and location of rhBMP-2 use in ASD surgery, at reported doses, do not increase acute major, neurological, or wound complications. Research is needed for higher rhBMP-2 dosing and long-term follow-up. 2.

Adult thoracolumbar and lumbar scoliosis treated with long vertebral fusion to the sacropelvis: a comparison between new hybrid selective spinal fusion versus anterior-posterior spinal instrumentation

Background contextCombined anteroposterior spinal fusion with instrumentation has been used for many years to treat adult thoracolumbar/lumbar scoliosis. This surgery remains a technical challenge to spine surgeons, and current literature reports high complication rates. PurposeThe purpose of this study is to validate a new hybrid technique (a combination of single-rod anterior instrumentation and a shorter posterior instrumentation to the sacrum) to treat adult thoracolumbar/lumbar scoliosis. Study designThis study is a retrospective consecutive case series of surgically treated patients with adult lumbar or thoracolumbar scoliosis. Patient sampleThis is a retrospective study of 33 matched pairs of patients with adult scoliosis who underwent two different surgical procedures: a new hybrid technique versus a third-generation anteroposterior spinal fusion. Outcome measuresPreoperative and postoperative outcome measures include self-report measures, physiological measures, and functional measures. MethodsIn a retrospective case-control study, 33 patients treated with the hybrid technique were matched with 33 patients treated with traditional anteroposterior fusion based on preoperative radiographic parameters. Mean follow-up in the hybrid group was 5.3 years (range, 2–11 years), compared with 4.6 years (range, 2–10 years) in the control group. Operating room (OR) time, estimated blood loss, and levels fused were collected as surrogates for surgical morbidity. Radiographic parameters were collected preoperatively, postoperatively, and at final follow-up. The Scoliosis Research Society Patient Questionnaire (SRS-22r) and Oswestry Disability Index (ODI) scores were collected for clinical outcomes. ResultsOperating room time, EBL, and levels fused were significantly less in the hybrid group compared with the control group (p<.0001). The postoperative thoracic Cobb angle was similar between the hybrid and control techniques (p=.24); however, the hybrid technique showed significant improvement in the thoracolumbar/lumbar curves (p=.004) and the lumbosacral fractional curve (p<.0001). The major complication rate was less in the hybrid group compared with the control group (18% vs. 39%, p=.01). Clinical outcomes at final follow-up were not significantly different based on overall SRS-22r scores and ODI scores. ConclusionThe new hybrid technique demonstrates good long-term results, with less morbidity and fewer complications than traditional anteroposterior surgery select patients with thoracolumbar/lumbar scoliosis. This study received no funding. No potential conflict of interest-associated bias existed.

Efficacy of combined anteroposterior fusion with no plate versus anterior fusion alone with cage and plate for multilevel degenerative cervical disease

Background contextMany studies have reported that anterior fusion alone has high rates of complications, such as pseudoarthrosis, graft subsidence, and graft dislodgement, with multisegmental constructs. No previous studies have compared the outcomes of combined anteroposterior fusion with no plate and anterior fusion alone with a cage and plate. PurposeTo compare the efficacy of combined anteroposterior fusion with that of anterior fusion alone for the treatment of multisegmental degenerative cervical disorder. Study designRetrospective study. Patient sampleSixty-two consecutive patients who underwent anterior fusion alone with a cage and plate or combined anteroposterior fusion with no plate for multisegmental (three or more segments) degenerative cervical disease. Outcome measureRadiological and clinical outcome measures. MethodsPatients in group A (n=36) underwent anterior fusion with a cage and plate construct (AFA); patients in group B (n=26) underwent combined anterior fusion with a cage and posterior fusion with a rod/screw construct (CAPF). The degree and maintenance of the correction angle, fusion rates, and adjacent level degeneration were assessed with radiographs. Clinical outcomes were assessed with a visual analog scale (VAS) and Neck Disability Index (NDI) scores, operative time, blood loss, and rates of complications. ResultsThe mean correction angle did not differ significantly between groups, but the loss of correction at final follow-up was greater in group A than group B (p=.001). Compared with group B, group A had a higher incidence of pseudarthrosis (p=.035), cage subsidence (p=.005), hardware-related complications (p=.032), and dysphagia (p=.012). The mean VAS score for arm pain and the mean NDI score were better for group B than group A (p=.0461, .0360), but the mean VAS score for posterior neck pain was better for group A than group B (p=.0352). Group B had greater blood loss and a longer operative time than group A (blood loss: p=.037; operative time: p=.0001). ConclusionsAlthough combined anterior/posterior fusion is associated with a longer operative time and greater blood loss than anterior fusion alone, the combined approach provides better maintenance of sagittal alignment, a higher rate of fusion, a lower incidence of cage subsidence and adjacent level disease, and better VAS and NDI scores.

Challenges of Spine Surgery in Patients With Chondrodysplasia Punctata

Chondrodysplasia punctata (CDP) is a common manifestation of an etiologically heterogenous group of disorders. There is very little data regarding the development and management of spinal deformity in patients with CDP. The purpose of this study was to present a multicenter series of CDP, to describe the surgical outcomes of spinal deformities in CDP patients and to emphasize important considerations that may influence choice of surgical treatment of spinal deformity in this patient population. The medical records and spinal radiographs of patients with the diagnosis of CDP followed in 2 centers between 1975 and 2011 were retrospectively reviewed. Epiphyseal stippling was present on radiographs in all patients who fulfilled the clinical criteria. Among the 17 patients who were diagnosed with CDP, 13 had spinal deformities. The mean age at diagnosis of spinal deformity was 14.6 months (range, 1 wk to 9 y). Males and females were close to equally represented (10 males and 7 females). Twelve patients (92%) required surgery to correct spinal deformity. Patients were followed for a median of 8.4 years (range, 2.8 to 19.5 y). The total number of surgical procedures performed was 17 averaging 1.5 per patient. Four patients required >1 procedure. Eighty percent of the patients who required >1 surgical procedure were females with probable diagnosis of X-linked dominant CDP. Revision surgery was indicated in 50% of the patients treated with combined anterior and posterior fusion and 20% of the patients treated with posterior fusion alone. Spinal deformity in CPD patients may range from significant kyphoscoliosis to minimal deformity that does not require any treatment. For those patients in whom spine surgery was indicated, a high incidence of revision surgery and curve progression after fusion was recorded. Female patients with probable diagnosis of X-linked dominant CDP were more likely to require a second surgical procedure. Isolated posterior fusion showed less favorable results compared with combined anteroposterior fusion in terms of revision surgery. Level IV-therapeutic study.

Upper Cervical Spine Fusion in Children With Skeletal Dysplasia

Skeletal dysplasias have been associated with upper cervical instability. Many patients are initially asymptomatic, but the instability may progress to subluxation and dislocation and complications thereof, including death. Surgery is hampered by petite osseous structures and low bone formation rate. To review the outcomes of surgical fusion of upper cervical instability in children with rare skeletal dysplasias. A retrospective study of eight children with five different rare skeletal dysplasias needing upper cervical instrumented stabilization. Cases were evaluated for clinical, radiologic, and quality-of-life outcomes, with median follow-up time of 5 years. Six patients underwent posterior, segmental cervical spine instrumentation and fusion (three C1/C2 fusions, three occipitocervical fusions), one anterior cervical instrumented spinal fusion, and one anteroposterior fusion. Autogenous bone grafting was used in all patients, and seven were immobilized using a halo body jacket. Nonunion in occipitocervical fusions was common in these patients (3/8 patients). Rib autograft from occiput to cervical spine with recombinant human BMP-2 was used to salvage nonunions. Surgical fixation in the pediatric cervical spine is hampered by fragile posterior structures. A postoperative immobilization by halo vest for 4 months is customary. Selective anterior corpectomy and plate fixation is not recommended in pediatric patients with skeletal dysplasias. Level 4, Case Series.

Stand-alone Anterior Versus Anteroposterior Lumbar Interbody Single-level Fusion After a Mean Follow-up of 41 Months

Prospective cohort study comparing evaluations of single-level anterior lumbar interbody fusion (ALIF) versus anteroposterior lumbar fusion (APLF). To clinically and radiologically compare the outcome after angle-stable, locked, stand-alone ALIF with that obtained after APLF, in cases with degenerative disc disease (DDD). Fusion rates have been reported to be highest after interbody fusion with transpedicular fixation. However, transpedicular fixation is linked to significant damage of the paravertebral muscles, to screw displacement-related neurological and vascular complications, and to an increased rate of adjacent segment degeneration. When performed as a stand-alone procedure, the disadvantages of transpedicular fixation can be completely avoided by ALIF. Eighty patients with chronic low-back pain due to a single-level DDD (Modic ≥2) and facet joint arthritis (Fujiwara ≥3) were enrolled in this study. Forty patients received an anteroposterior fusion (ALIF with transpedicular fixation: APLF group) and 40 patients (ALIF group) were treated with a stand-alone ALIF using the Synfix-LR device. At 7 days, 3, 6, 12, and 24 months, and at a mean follow-up of 41 months, patients were clinically (visual analog scale, Oswestry Low Back Pain Disability Index, satisfaction) and radiologically (x-ray, and at 12 months, thin-slice computed tomography) compared. Blood loss and duration of surgery were significantly lower in the ALIF group (P<0.001). Visual analog scale and Oswestry Low Back Pain Disability Index improved significantly over time (analysis of variance, P<0.001) in both groups, but both scores were significantly better in ALIF group (analysis of variance, P<0.001). Patients' satisfaction consistently ranked higher in the ALIF group (P=0.042 at 12 mo). No significant difference was found in the fusion rate throughout the study. Stand-alone ALIF leads to better clinical results than APLF, without differences in fusion rates after 41 months. Therefore, when a posterior approach is not needed for decompression or reposition, we suggest performing a stand-alone ALIF in cases with single-level DDD.

Lumbar Lordosis Restoration Following Single-level Instrumented Fusion Comparing 4 Commonly Used Techniques

A major sequelae of lumbar fusion is acceleration of adjacent-level degeneration due to decreased lumbar lordosis. We evaluated the effectiveness of 4 common fusion techniques in restoring lordosis: instrumented posterolateral fusion, translumbar interbody fusion, anteroposterior fusion with posterior instrumentation, and anterior interbody fusion with lordotic threaded (LT) cages (Medtronic Sofamor Danek, Memphis, Tennessee). Radiographs were measured preoperatively, immediately postoperatively, and a minimum of 6 months postoperatively. Parameters measured included anterior and posterior disk space height, lumbar lordosis from L3 to S1, and surgical level lordosis.No significant difference in demographics existed among the 4 groups. All preoperative parameters were similar among the 4 groups. Lumbar lordosis at final follow-up showed no difference between the anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cage groups, although the posterolateral fusion group showed a significant loss of lordosis (-10°) (P<.001). Immediately postoperatively and at follow-up, the LT cage group had a significantly greater amount of lordosis and showed maintenance of anterior and posterior disk space height postoperatively compared with the other groups. Instrumented posterolateral fusion produces a greater loss of lordosis compared with anteroposterior fusion with posterior instrumentation, translumbar interbody fusion, and LT cages. Maintenance of lordosis and anterior and posterior disk space height is significantly better with anterior interbody fusion with LT cages.

Pediatric Cervical Kyphosis

Retrospective study. To compare arthrodesis techniques for pediatric cervical kyphosis. Cervical kyphosis is rare in the pediatric population. The most common etiologies are acquired instabilities or an underlying syndrome. The largest pediatric case series in the literature describes the treatment of nine patients. A retrospective review was performed of pediatric patients treated for cervical kyphosis with posterior spinal fusion (PSF), anterior spinal fusion (ASF) with strut graft, or anteroposterior fusion with strut graft (A/PSF). Patients were divided into groups on the basis of the etiology of the kyphosis. Group 1 was composed of patients with acquired instability, either traumatic or postlaminectomy. Group 2 was composed of patients with syndromic deformity. Twenty-four patients were identified: 9 in group 1 and 15 in group 2. Arthrodesis techniques performed in group 1 were 2 PSF, 2 ASF, and 5 A/PSF and in group 2 were 11 PSF, 0 ASF, and 4 A/PSF. Primary union was achieved in all group 1 patients with no major complications. Pseudarthrosis and other major complications were frequent in group 2. Among syndromic patients (group 2) treated with primary PSF (11 patients), the mean immediate postoperative kyphosis was 32° in seven patients who achieved primary union and 77° in four patients with pseudarthrosis who required reoperation (P = 0.022); two of these four patients with pseudarthrosis developed late myelopathy with an episode of transient quadriparesis. Primary union was achieved in three of four syndromic patients with A/PSF; pseudarthrosis occurred in the patient with Gorham's disease. Arthrodesis was effective without major complications in nonsyndromic kyphosis. Complications were frequent in syndromic kyphosis. There was a significant association of greater residual kyphosis with pseudarthrosis in syndromic patients treated with PSF alone. Circumferential arthrodesis with strut grafting may decrease pseudarthrosis risk in syndromic patients with severe, rigid kyphosis. PSF alone may be sufficient in syndromic patients with flexible kyphosis when adequate postoperative correction is achieved.

Spontaneous fusion across the apex of severe thoracolumbar Scheuermann’s kyphosis: A surgical consideration

Considerable debate exists regarding the pathogenesis, natural history and treatment of Scheuermann’s kyphosis. Surgical correction is indicated in the presence of severe kyphosis which carries the risk of neurological complications, persistent back pain and significant cosmetic deformity. This can be achieved through a posterior-only or an anteroposterior approach. Spontaneous fusion in association with Scheuermann’s kyphosis has not been previously described. This is an important consideration if surgical correction of the kyphosis is planned. Two patients with severe thoracolumbar Scheuermann’s kyphosis who developed spontaneous posterior and anteroposterior fusion across the apex of the deformity are presented. The surgical treatment and final outcome is discussed.

Surgical Revision Rates of Hooks Versus Hybrid Versus Screws Versus Combined Anteroposterior Spinal Fusion for Adolescent Idiopathic Scoliosis

Multi-institution retrospective review. To determine the surgical revision rates of hook, hybrid, anteroposterior, and total pedicle screw constructs for adolescent idiopathic scoliosis (AIS). Much debate continues on the safety, efficacy, and cost of thoracic pedicle screws. Nonetheless, there are no large series that have evaluated the revision rate of various constructs in AIS to determine the need for repeat surgery, and therefore, the added indirect costs and risks of additional procedures. We retrospectively reviewed the surgical case logs of 1428 patients with AIS at 2 institutions from 1990 to 2004, and the clinical records and radiographs of revision cases. Patients were classified into 1 of 4 groups: hook, hybrid hook and screw, all pedicle screw, and combined anteroposterior fusion constructs. Overall, there were 65 (4.6%) returns to the operating room, or 55 (3.9%) cases after excluding infections without concomitant pseudarthrosis. Of the 65 revision cases, there were 52 females and 13 males, at an average age at first surgery of 13.9 years (range, 9-18 years), and an average age at revision of 14.7 years (range, 12-23 years). For the revision cases, the average initial Cobb was 61.9 degrees (range 44 degrees -110 degrees ), and this was not statistically different within the cohorts (P > 0.05). In terms of revision rate, all hook constructs had a higher revision rate secondary to instrumentation failure when compared with screws, while both hook and hybrid constructs had an overall higher surgical revision rate when compared with screw constructs or anteroposterior constructs (all P <or= 0.05). The pseudarthrosis rate trended toward, but did not meet, statistical significance between these same groups. All pedicle screw and anteroposterior constructs have a lower surgical revision rate when compared with hook and hybrid constructs. The hidden patient and financial costs of these findings should be considered when evaluating overall instrumentation efficacy.

Poster 282: Unstable Jefferson Fracture as an Etiology for Persistent Dysphagia and Dysphasia in a Tetraplegic Patient: A Case Report

Setting: University hospital, rehabilitation ward. Patient: A 37-year-old C4 tetraplegic, 1 month postinjury, with persistent dysphagia and dysphasia. Case Description: The patient was admitted following a motorcycle crash, with resultant C4 complete tetraplegia. Immediately postinjury, prior to intubation, the patient was vocalizing. Injuries included: stable Jefferson (C1) fracture, C2 complex fracture, C5 fracture and small frontal subdural hematoma. Operative management included C5 corpectomy and C4-7 anteroposterior fusion.