Jean Marc Vital

Angle Measurement Reproducibility Using EOSThree-Dimensional Reconstructions in Adolescent Idiopathic Scoliosis Treated by Posterior Instrumentation

Study Design. A reproducibility study was conducted in preoperative and postoperative three-dimensional (3D) measurements for patients operated for adolescent idiopathic scoliosis (AIS). Objective. To assess the reliability of preoperative and postoperative 3D reconstructions using EOS in patients operated for AIS. Summary of Background Data. No prior reliability study of 3D measurements has been performed in the literature for severe scoliosis and for operated patients. Methods. This series included 24 patients (62° ± 11) operated for Lenke 1 or 2 AIS, using either all-pedicle screw constructs (group 1) or hybrid constructs, with universal clamps at thoracic levels (group 2). All patients underwent low-dose standing biplanar radiographs, pre- and postoperatively. Three operators performed the 3D reconstruction process two times preoperatively and two times postoperatively (total 288 reconstructions). Intraoperator repeatability and interoperator reproducibility were calculated and compared between groups. Results. The preoperative reproducibility was between 4° and 6.5° for parameters dedicated to scoliosis (Cobb and apical vertebral rotation), between 4° and 7° for kyphosis and lordosis values, and between 1° and 5° for pelvic measurements. The postoperative reproducibility was between 5° and 8° for values of kyphosis and lordosis, between 1° and 5.5° for pelvic parameters, and between 6.5° and 10.5° for the scoliotic parameters. The reproducibility of the scoliotic parameters was slightly better in the hybrid construct group, but the difference was not significant (P = 0.8). No difference was found between groups for the other parameters. Conclusion. 3D postoperative reconstructions are as reproducible as preoperative ones. The reproducibility is not influenced by the type of implant used for correction. Mean difference between operator was higher than previously reported for the apical rotation measurement, but this difference can be explained by the severity of the curves and the lower visibility of the anatomical landmarks due to the implants.

Course of spinal solitary osteochondromas.

Study Design. Six spinal solitary osteochondromas. Objectives. To evaluate the course of spinal cord compression after surgery, and the risk of local recurrence and malignant transformation, based on the present series and cases reported in the literature. Summary of Background Data. Spinal cord compression by a solitary osteochondroma is rare. Little is known concerning neurologic improvement after decompression of the spinal cord or the risk of recurrence or malignant transformation of spinal solitary osteochondroma, because most of the cases reported are isolated. Methods. Clinical history, plain radiographs, pathologic features, computed tomographic studies, and magnetic resonance imaging were reviewed. Five patients underwent long-term follow-up physical examination and computed tomography for an average of 6 years (range, 2–12 years) after surgical treatment. The literature was reviewed for solitary osteochondroma with spinal cord compromise, recurrent solitary osteochondroma, or solitary osteochondroma in the process of sarcomatous transformation. Results. In the present study, two of the six patients experienced spinal cord compromise. Neurologic deficits improved after surgery. None of the patients had local recurrence or malignant transformation at follow-up observation. Including these two patients, the authors found 62 cases of solitary osteochondroma with spinal cord compromise in the literature. Overall, three patients died, eight did not improve, and 48 (81%) experienced regression of the neurologic deficit after surgical decompression. Among the 150 cases of solitary osteochondroma the authors found in the literature, there were six cases (4%) of local recurrence and four cases (2.7%) of malignant transformation. Conclusions. Surgical treatment improves neurologic deficit in more than 80% of cases of spinal cord compromise caused by solitary osteochondroma. The risk of recurrence or sarcomatous transformation justifies clinical and radiologic follow-up review.

Reduction technique for uni- and biarticular dislocations of the lower cervical spine.

Study Design. A technical report concerning the methods of reduction of dislocations of the lower cervical spine used in 168 consecutive cases (77 unilateral and 91 bilateral dislocations). Objectives. To evaluate the efficacy of a reduction protocol comprising three successive phases: reduction by traction, reduction by closed maneuvers with the patient under general anesthesia, and open reduction. Summary of Background Data. Management of cervical dislocations varies greatly among spine treatment centers, especially concerning the upper limit of traction, the safety of closed manipulations in anesthetized patients, and the approach preferred when surgical reduction is necessary. Methods. Reduction by gradual traction without anesthesia was attempted first. In case of failure, specific closed manipulations were used with the patient under general anesthesia just before anterior arthrodesis was performed. If this failed, anterior surgical reduction was attempted. Anterior fusion was performed in every patient, even when closed reduction was successful, because of the lasting instability produced by attending ligamentous lesions. Results. Of the patients in 168 cases of dislocation, the protocol failed in 5, all of whom had longstanding unilateral dislocation. Of the 91 with bilateral dislocation, reduction was achieved by simple traction in 39 (43%), by maneuvers with the patient under general anesthesia in 27 (30%), and by anterior surgery in 25 (27%). Among the patients in 77 cases of unilateral dislocation, reduction was achieved by traction in 18 (23%), by external maneuvers in 28 (36%), and by anterior surgery in 26 (34%). In 7 patients, discal herniation engendering neurologic signs was resected during anterior surgery. No neurologic deterioration during or immediately after reduction by this protocol was observed. Conclusions. This protocol consists of application of rapidly progressive traction, followed if necessary by one or two reduction maneuvers with the patient under general anesthesia. If both methods fail, specific surgical procedures using an anterior exposure seem to be reliable, in that anatomic reduction was obtained in 163 of 168 patients without neurologic deterioration.

Three-dimensional spinal and pelvic alignment in an asymptomatic population.

Study Design. A 3-dimensional (3-D) analysis of asymptomatic spinal and pelvic alignment. Objective. To obtain 3-D reference values of spinal and pelvic parameters, vertebral and intervertebral orientations. Summary of Background Data. Referential values of spine and pelvis alignment are essential for the assessment of posture and balance. However, only 2-D referential values have been reported using standing sagittal radiographs, and, to our knowledge, no 3-D referential values have been reported to date. Methods. A biplanar radiographic technique was used to obtain the 3-D reconstruction of the spine and pelvis of 34 asymptomatic standing subjects. The 3-D values were calculated for most of the spinal and pelvic parameters. In addition, 3-D vertebral and intervertebral orientations were computed, and the apical and junctional zones were investigated. Results. As reported in 2-D, a large variability and particular correlations were observed for the 3-D spinal and pelvic parameters. However, significant differences were found between 3-D and 2-D values. The 3-D vertebral and intervertebral sagittal rotations showed specific features in the apical and junctional zones of the asymptomatic spine. Conclusion. These data may be used as 3-D referential values of spinal and pelvic alignment.

One-Level Lumbar Degenerative Spondylolisthesis And Posterior Approach. Is Transforaminal Lateral Interbody Fusion Mandatory? A Randomized Controlled Trial With Two Year Follow-Up.

Study Design. A monocentric open-label randomized controlled trial (MRCT). Objective. Comparison of clinical and radiological outcomes between isolated instrumented posterior fusion (PLF) and associated instrumented posterior fusion and interbody fusion by transforaminal approach (PLF + TLIF) for patients suffering from one-level lumbar degenerative spondylolisthesis (DS) undergoing surgery. Summary of Background Data. DS is a common cause of symptomatic lumbar stenosis. PLF has shown better clinical outcome than decompression with noninstrumented posterolateral fusion. TLIF with interbody cage showed better fusion rate than PLF. There is a need for randomized controlled trials to compare PLF with and without TLIF as to clinical and radiological outcomes. Methods. This is a MRCT comparing PLF and TLIF techniques in surgical treatment of DS. Sixty patients were included in a secured database from 2009 to 2011 and randomized into two groups: 30 PLF with posterior pedicle screws and intertransverse autologuous graft, and 30 TLIF in which an interbody fusion by transforaminal approach was added. Data included clinical (pain and disability), surgical (blood loss and operating time), and radiological (alignment and fusion) parameters at baseline and 2-year follow-up. Comparison was made by Student t test and Chi-square test. Results. There was a significant improvement in each group for pain and disability but no difference between the groups. Radiographic assessment showed better posterolateral fusion rate for TLIF without superiority in segmental lordosis improvement. A case of deformity cascade with spino-pelvic mismatch at baseline was noted in PLF. Conclusion. Posterior decompression and instrumented fusion is an efficient technique that proved its significant clinical benefit in the surgical treatment of DS. TLIF did not show its superiority neither in clinical nor alignment parameters despite a better fusion rate. These results suggest that TLIF is not mandatory in this specific indication. Sagittal alignment analysis by standing full-body images should be considered in DS care. Level of Evidence: 2

Centering of cervical disc replacements: usefulness of intraoperative anteroposterior fluoroscopic guidance to center cervical disc replacements: study on 20 discocerv (scient'x prosthesis).

Study Design. This is a prospective randomized computed tomographic scan study on the centering of cervical disc prosthesis (Discocerv; Scient’X) with and without anteroposterior (AP) fluoroscopic guidance. Objective. Analyze interest of AP fluoroscopic guidance for coronal positioning in cervical disc replacements. Summary of Background Data. This series consisted of 20 patients. One group of 10 patients was operated using only lateral fluoroscopic guidance (L guidance) and the other group of 10 patients was operated using both lateral and AP fluoroscopic guidance (AP + L guidance). Total disc replacements positioning is analyzed in the 2 groups. Methods. All patients had a computed tomographic scan 24 hours after surgery. Specific reconstructions were obtained from the native slices. Three planes P1, P2, and P3 are defined to quantify centering of the prosthesis in axial sagittal and coronal planes. Results. In the coronal plane P1, there is no difference in lateralization between the L guidance (absolute value of average M = 0.93 mm; SD = 0.59 mm) and AP + L guidance groups (M = 1.28 mm; SD = 0.75 mm). In the axial plane, there is no difference in lateralization between the L guidance and AP + L guidance groups. In the L guidance group, average was 1.96° (SD = 1.43°) and 3.18° (SD = 2.94°) in AP + L guidance. There is no significative difference between 2 groups in coronal (P = 0.26) and axial plane (P = 0.19). Conclusion. Unci are reliable landmarks for coronal centering of total disc replacements. AP fluoroscopic guidance does not improve this positioning.

Advantages and Disadvantages of Adult Spinal Deformity Surgery and its Impact on Health-related Quality of Life.

Study Design. Prospective multicenter study of adult spinal deformity (ASD) surgery. Objective. To clarify the effect of ASD surgery on each health-related quality of life (HRQOL) subclass/domain. Summary of Background Data. For patients with ASD, surgery offers superior radiological and HRQOL outcomes compared with nonoperative care. HRQOL may, however, be affected by surgical advantages related to corrective effects, yielding adequate spinopelvic alignment and stability or disadvantages because of long segment fusion. Methods. The study included 170 consecutive patients with ASD from a multicenter database with more than 2-year follow-up period. We analyzed each HRQOL domain/subclass (short form-36 items, Oswestry Disability Index, Scoliosis Research Society-22 [SRS-22] questionnaire), and radiographic parameters preoperatively and at 1 and 2 years postoperatively. We divided the patients into two groups each based on lowest instrumented vertebra (LIV; above L5 or S1 to ilium) or surgeon-determined preoperative pathology (idiopathic or degenerative). Improvement rate (%) was calculated as follows: 100 × |pre.–post.|/preoperative points (%) (+, advantages; –, disadvantages). Results. The scores of all short form-36 items and SRS-22 subclasses improved at 1 and 2 years after surgery, regardless of LIV location and preoperative pathology. Personal care and lifting in Oswestry Disability Index were, however, not improved after 1 year. These disadvantages were correlated to sagittal modifiers of SRS-Schwab classification similar to other HRQOL. The degree of personal care disadvantage mainly depended on LIV location and preoperative pathology. Although personal care improved after 2 years postoperatively, no noticeable improvements in lifting were recorded. Conclusion. HRQOL subclass analysis indicated two disadvantages of ASD surgery, which were correlated to sagittal radiographic measures. Fusion to the sacrum or ilium greatly restricted the ability to stretch or bend, leading to limited daily activities for at least 1 year postoperatively, although this effect may subside after another year. Consequently, spinal surgeons should note the effect of surgical treatment on each HRQOL domain and counsel patients about the implications of surgery. Level of Evidence: 4

Complications following anterior approaches to the cervical spine. Review of 535 surgical procedures

SummaryThe authors present a retrospective study of 535 consecutive anterior approaches to the cervical spine back to 5 years. The data were analyzed for post-operative complications. This surgical procedure has been commonly used for more than 40 years, but the post-operative complications due to the anterior approach itself were presented with few accompanying statistics, with various and contradictory results. Injury to nearly all of the structures has been reported in the literature, the more frequent problems are hoarseness and dysphagia; other complications include perforation of the oesophagus, hematomas, vascular injury⋯Analysis of this data allows to understand better the specific problems related to this surgical approach, and to suggest precautions at each stage of the course of exposure of cervical vertebrae.

Conversion paralysis after cervical spine arthroplasty: A case report and literature review

We report a case of conversion paralysis after cervical spine arthroplasty performed in a 45-year-old woman to treat cervico-brachial neuralgia due to a left-sided C6-C7 disc herniation. Upon awakening from the anaesthesia, she had left hemiplegia sparing the face, with normal sensory function. Magnetic resonance imaging (MRI) of the brain ruled out a stroke. MRI of the spinal cord showed artefacts from the cobalt-chrome prosthesis that precluded confident elimination of mechanical spinal cord compression. Surgery performed on the same day to substitute a cage for the prosthesis ruled out spinal cord compression, while eliminating the source of MRI artefacts. Findings were normal from follow-up MRI scans 1 and 15days later, as well as from neurophysiological testing (electromyogram and motor evoked potentials). The deficit resolved fully within the next 4days. A psychological assessment revealed emotional distress related to an ongoing divorce. The most likely diagnosis was conversion paralysis. Surgeons should be aware that conversion disorder might develop after a procedure on the spine, although the risk of litigation requires re-operation. Familiarity with specific MRI sequences that minimise artefacts can be valuable. A preoperative psychological assessment might improve the detection of patients at high risk for conversion disorder.

Global Spinal Alignment in Patients with Cervical Spondylotic Myelopathy

Study Design. A prospective radiographic analysis of cervical spondylotic myelopathy (CSM). Objective. The aim of this study was to clarify the pathophysiology of CSM, and use the characteristic of global spinal alignment for determining the surgical strategy. Summary of Background Data. Radiographic evaluation of CSM, in general, comprises cervical magnetic resonance imaging (MRI) and regional cervical radiography, which cannot distinguish between cervical hyperlodorsis with spinopelvic compensation and cervical lordorsis with normal global alignment. Methods. Our inclusion criteria were preoperative whole spine radiography and cervical MRI and health-related quality of life scores. Global spinal alignment was characterized by cervical lordosis (CL), C7 sagittal vertical axis (SVA), T1 slope (T1S), thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), and knee flexion angle (KFA). Cervical alignment was characterized by O-C2, C2–4, C5–7, and C2–7 angles; cranial center of gravity (CCG) C7SVA; and C2–7 SVA. Responsible lesion determined using MRI was divided from C2/3 to C7/T1. Results. Eighty-eight surgically treated CSM patients with EOS full spine imaging were prospectively analyzed. There were 72 normal (Type 1; SVA <50 mm) and 16 positive (Type 2; SVA ≥50 mm) global balance patients. There were significant differences in age, T1S, KFA, T1S-CL, SVA, CCG-SVA, and C2–7 SVA between Type 1 and Type 2. C3/4 lesion was more common in Type 2 than in Type 1. There was a positive correlation between global sagittal, but not regional, balance, and responsible lesion. C3/4 lesion was more frequent in older, male, high SVA, large T1S-CL, large KFA, and large cranial lordosis (C2–4/C5–7 angle) patients. Conclusion. This study indicates the necessity for global alignment evaluation, particularly in older CSM patients because of their compensation mechanism for global malalignment. Surgical strategy for cranial type CSM should be carefully selected considering global balance. Level of Evidence: 4