Olivier Gille

Course of Modic 1 six months after lumbar posterior osteosynthesis.

Study Design. A prospective study was conducted to investigate the outcome of the Modic Type 1 inflammatory signal in magnetic resonance imaging (MRI) in 17 patients with chronic low back pain 6 months after instrumented posterior lumbar arthrodesis. Objective. To assess the course of the inflammatory signal after stabilization of a painful intervertebral segment by posterior instrumentation alone visualized on MRI systematically performed 6 months after the operation. Summary of Background Data. In 1988, Modic and colleagues described three degenerative stages of vertebral endplates and subchondral bone. The inflammatory stage, or Stage 1, is correlated with substantial functional disability. According to these authors, Stage 1 lesions naturally transform into Stage 2, the fatty stage. In the literature, patients with Modic 1 signal tend to have good results after arthrodesis, better than those with Modic 2 lesions. Methods. This study included 17 patients (average age, 46 years) who had experienced chronic low back pain more than 1 year and showed Modic 1 changes in MRI and disc narrowing on plain radiographs. Every patient underwent posterior screw–rod osteosynthesis and posterolateral arthrodesis. Disc disease had occurred subsequently to discectomy (n = 7), rapidly destructive disc disease (n = 5), or spondylolisthesis resulting from spondylolysis (n = 5). Clinical results were assessed according to a visual analog scale for pain, a functional disability score for the evaluation of patients with low back pain (Eiffel), and the validated French version of the self-administered Dallas quality-of-life test (DRAD). Results. Systematic MRI at 6 months showed transformation from Modic 1 to Modic 0 (normal endplate signal) in 4 patients and transformation from Modic 1 to Modic 2 in the remaining 13 patients. Clinical evaluation was performed at 6 months (at the same time as the MRI) and at 1 year. In every patient, there was improvement in the visual analog score and the functional score, which remained stable at 1 year. Conclusions. According to the literature, most Modic 1 lesions change to become Stage 2 lesions in 18 to 24 months. In this study, 17 patients with Modic Type 1 signal had changes after 6 months. It appears that posterior osteosynthesis combined with posterolateral arthrodesis accelerates the course of Modic 1 lesions, probably by correcting mechanical instability.

Incidental durotomy during spine surgery: Incidence, management and complications. A retrospective review

STUDY DESIGN Retrospective review of a series of patients who underwent spinal surgery at a single spine unit during a 1 year period. OBJECTIVES To assess the incidence, treatment, clinical consequence, complications of incidental durotomy during spine surgery and results of 37 months clinical follow-up. SUMMARY OF BACKGROUND DATA Incidental durotomy is an underestimated and relatively adverse event during spinal surgery. Several consequences of inadequately treated dural tears have been reported. METHODS A retrospective review was conducted on 1326 consecutive patients who underwent spinal surgery performed in one French spine unit from January 2005 to December 2005. We excluded from this study patients treated for emergency spine cases. RESULTS Fifty-one dural tears were identified (3.84%). Incidental durotomies were associated with anterior cervical approach in 1 case, with posterior cervical approach in 1 case, with anterior retroperitoneal approach in 1 case and with posterior thoracolumbar approach in 48 cases. In addition, any clinically significant durotomy unrecognised during surgical procedure were included. Thirteen patients presented postoperative complications including 7 cerebrospinal fluid leaks, 2 wound infections, 2 postoperative haematomas, and 2 pseudomeningoceles. Nine of these 13 patients required a revision procedure. A mean follow-up of 37 months showed good long-term clinical results. CONCLUSIONS Incidental durotomy is a common complication of spine surgery. All incidental durotomies must be repaired primarily. Dural tears that were immediately recognised and treated accordingly did not lead to any significant sequelae at a mean follow-up of 37 months. However, long-term follow-up studies will be needed to confirm this finding. The risks associated with dural tears and cerebrospinal fluid leaks are serious and should be discussed with any patients undergoing spine surgery.

Erector spinae muscle changes on magnetic resonance imaging following lumbar surgery through a posterior approach.

Study Design. Prospective randomized study of patients undergoing lumbar arthrodesis. Objectives. To quantify MRI changes of the erector spinae following lumbar surgery through a posterior approach and the possible protection of these muscles during surgery by the use of cholinergic blockade. Summary of Background Data. It has been shown that lumbar spine surgery through a posterior approach can induce iatrogenic lesions in the erector spinae. We have shown in a previous study that histologic changes on muscular biopsy performed in the multifidus at the end of the surgical procedure were not modified by the use of cholinergic blockade during surgery. Methods. Twenty patients scheduled to undergo pedicle-screw enhanced L4–L5 arthrodesis were enrolled in this study. Ten patients received curare during anesthesia and 10 patients did not. MRI was obtained the day before the operation and at 6 months of follow-up on the same MR scanner. T1-weighted images were obtained in the axial plane. The 2 slices immediately proximal and distal to the pedicle screw construct on the postoperative MRI were selected. The corresponding slices were selected on the preoperative MRI. Each erector spinae on the 4 slices was surrounded using a mouse-guided tool. The contractile component of the cross-sectional area (CCSA) was calculated from the number of pixels surrounded and the signal intensity of each pixel. Results. There was only slight changes in the erector spinae CCSA proximal to a posterior lumbar arthrodesis. Erector spinae CCSA decreased by 27% distal to the arthrodesis. Curare showed no efficacy in preventing muscle damage. Conclusions. Erector spinae muscle alterations mainly occur distal to posterior lumbar surgical procedures.

Reliability of 3D reconstruction of the spine of mild scoliotic patients.

Study Design. A reliability study was conducted in quantitative 3-dimensional (3D) measurements for mild scoliosis. Objective. To evaluate the intrarater and interrater reliability of a computer tool used for 3D reconstruction of the spine. Summary of Background Data. No reliability study of spinal in vivo 3D medical imaging measurements has been performed in the literature. Methods. This study included 30 patients (mean age 13 years) with mild idiopathic scoliosis. Spinal 3D reconstruction was performed using a new technique called semiautomatic 3D reconstruction, which requires only the location of the corners of each vertebral body on 2 orthogonal views. Three raters performed the 3D reconstruction procedure on the 30 pairs of radiographs in random order. One of the raters repeated the procedure for the 30 patients 15 days later. Inter-reliability and intra-reliability were estimated for different parameters: thoracic kyphosis, lumbar lordosis, Cobb’s angle, pelvic morphologic and positional parameters, and axial rotation. Results. Intraclass correlation coefficient showed good or very good agreement for most of the measurements. The 95% prediction limits are approximately 4° for the measurements of spinal curves, 2° for pelvic parameters, and axial vertebral rotation. Conclusions. The reliability of 3D reconstruction of the spine is acceptable, and this technique can be used for clinical studies.

Surgical treatment of greater Occipital neuralgia by neurolysis of the greater Occipital nerve and sectioning of the inferior oblique muscle

Objectives. To evaluate a new surgical treatment consisting of neurolysis of the great occipital nerve and section of the inferior oblique muscle. Design. A retrospective study of 10 patients operated for greater occipital neuralgia. Summary and Background Data. This technique is based on a previous anatomic cadaver study. The greater occipital nerve is stretched by the inferior oblique muscle of the head during flexion of the cervical spine. Sectioning this muscle relaxes the greater occipital nerve. With this procedure, the authors systematically associate release of the nerve down to the inferior edge of the inferior oblique muscle. Methods. A retrospective study was conducted of 10 patients operated on from January 1998 to December 1999 for greater occipital neuralgia. All the patients had pain exacerbated by flexion of the cervical spine. The average age of the patients was 62 years. The mean follow-up of the series was 37 months. The results of the treatment were assessed according to three criteria: 1) degree of pain on a Visual Analogue Scale before surgery, at 3 months, and at last follow-up; 2) consumption of analgesics before surgery and at follow-up; and 3) the degree of patient satisfaction at follow-up. Results. In three cases, anatomic anomalies were found. One patient had hypertrophy of the venous plexus around C2. In another, the nerve penetrated the inferior oblique muscle. The third had degenerative C1–C2 osteoarthritis requiring associated C1–C2 arthrodesis. The mean Visual Analogue Scale score was 80/100 before surgery and 20/100 at last follow-up. Consumption of analgesics decreased in all patients. Seven of the 10 patients were very satisfied or satisfied with the operation. Conclusion. This surgical technique gives good results on greater occipital neuralgia if patients are well chosen. Nerve release is justified by the frequency of associated anatomic abnormalities.

Analysis of hard thoracic herniated discs: review of 18 cases operated by thoracoscopy

The authors retrospectively reviewed a series of 18 hard thoracic herniated discs (HTHD) operated by thoracoscopy. Isolated cases of HTHD have been reported in the literature, but no series describing these lesions has been published. Seventy-two percent of the herniated discs were situated between T8 and T12. Fifty-six percent of the patients had radiographic sequelae of Scheuermann’s disease. Postoperatively, 83% had neurological improvement. In seven cases (39%), a plane separating the herniated disc and the dura mater was found surgically. In 11 patients, no separating plane was found during surgery. The lesion was intradural in three patients (17%) and adherent to the dura mater in eight (44%). Among these 11 patients, surgery was complicated by a dural tear in the first seven that led to a high risk of cerebrospinal fluid fistula: four of these seven patients had required surgical revision. In the last four, the zone of adhesion of the HTHD to the dura mater was preserved, successfully preventing dural tear

Computerized preoperative planning for correction of sagittal deformity of the spine

PurposeVarious methods of preoperative planning have been described for the correction of spinal sagittal deformities. They are reliable on condition that the thoracolumbar spine is totally fused and enable only the simulation of pedicle subtraction osteotomy (PSO). In this study, a new theoretical planning that can be used regardless of the etiology of the deformity and the type of osteotomy is described and assessed.MethodsThe spino-pelvic sagittal balance can be expressed by two parameters: pelvic tilt (PT) and center of both acoustic meati (CAM) overhang. These two parameters vary according to the type, number, level, and angulation of osteotomies. The general principle of the planning is to define the surgical program in order to obtain PT and CAM overhang as close as possible to the normal values. The theoretical planning is based on a trigonometric construction which depends on numerous factors and is challenging to use in daily practice without the aid of a software tool. Modifications are proposed if the spine cannot be modeled as a solid beam due to unfused disks allowing relative motion. The SpineView software, which enables analysis and quick visualization of different correction possibilities, is presented. The planning method is assessed in a prospective cohort of 11 patients by comparing planned values of spino-pelvic parameters to postoperative values.ResultsIn all, 8 preoperative plans out of 11 were concordant with the postoperative results.ConclusionsThe preoperative planning enables the surgeon to estimate the clinical effects of the different surgical techniques in order to choose the best procedure for a given patient.

The lumbosacral plexus: anatomic considerations for minimally invasive retroperitoneal transpsoas approach

PurposeThe minimally invasive transpsoas approach can be employed to treat various spinal disorders, such as disc degeneration, deformity, and lateral disc herniation. With this technique, visualization is limited in comparison with the open procedure and the proximity of the lumbar plexus to the surgical pathway is one limitation of this technique. Precise knowledge of the regional anatomy of the lumbar plexus is required for safe passage through the psoas muscle. The primary objective of this study was to determine the anatomic position of the lumbar plexus branches and sympathetic chain in relation to the intervertebral disc and to define a safe working zone. The second objective was to compare our observations with previous anatomical studies concerning the transpsoas approach.MethodsA total of 60 lumbar plexus in 8 fresh cadavers from the Department of Anatomy were analyzed in this study. Coronal and lateral X-Ray images were obtained before dissection in order to eliminate spine deformity or fracture. All cadavers were placed in a lateral decubitus position with a lateral bolster. Dissection of the lumbar plexus was performed. All nerve branches and sympathetic chain were identified. Intervertebral disc space from L1L2 to L4L5 was divided into four zones. Zone 1 being the anterior quarter of the disc, zone 2 being the middle anterior quarter, zone 3 the posterior middle quarter and zone 4 the posterior quarter. Crossing of each nervous branch with the disc was reported and a safe working zone was determined for L1L2 to L4L5 disc levels. A safe working zone was defined by the absence of crossing of a lumbar plexus branch.ResultsNo anatomical variation was found during blunt dissection. As described previously, the lumbar plexus is composed of the ventral divisions of the first four lumbar nerves and from contributions of the sub costal nerve from T12. The safe working zone includes zones 2 and 3 at level L1L2, zone 3 at level L2L3, zone 3 at level L3L4, and zone 2 at level L4L5. No difference was observed between right and left sides as regards the relationships between the lumbar plexus and the intervertebral disc.ConclusionWe observed some differences concerning the safe working zone in comparison with other cadaveric studies. The small number of cadaveric specimens used in anatomical studies probably explains theses differences. The minimally invasive transpsoas lateral approach was initially developed to reduce the complications associated with the traditional procedure. The anatomical relationships between the lumbar plexus and the intervertebral disc make this technique particularly risky a L4L5. Alternative techniques, such as transforaminal interbody fusion (TLIF), posterior lumbar interbody fusion (PLIF) or anterior interbody fusion (ALIF) should be used at this level.

Posterior spinal fusion from T2 to the sacrum for the management of major deformities in patients with Parkinson disease: a retrospective review with analysis of complications.

Study Design: Description of the surgical management of major spinal deformities in patients with Parkinson disease (PD). Objective: To evaluate the effectiveness of the construct, the incidence and types of complications, and patient satisfaction. Summary of Background Data: The association of degenerative, neuromuscular, and osteoporotic diseases in PD can lead to major complications after spine surgery. We treated PD patients with major spinal deformities by a posterior-only approach for spinal fusion from T2 to the sacrum. Methods: This retrospective study reviews 12 consecutive patients with PD undergoing this surgery in a 2-year span at a single institution. Radiographs were taken with the EOS low-dose system (EOS Imaging, Paris, France) before and 3 months after surgery and at the last follow-up visit and were evaluated by a spine surgeon not involved in the surgery. Complications were analyzed. The functional outcome was assessed with the SRS-30 questionnaire. Results: The patients’ mean age was 68±6.2 years, the mean duration of PD 10±4.9 years, and the mean follow-up 32.8±6.9 months. Six patients had first surgeries, and 6 revisions. Statistically significant improvement was observed in all patients in the frontal and the sagittal planes after surgery. The sagittal vertical axis improved from 15.2±9.3 cm preoperatively to 0.5±3.2 cm at the last follow-up. Six patients had revision, 3 times for instrumentation failure, twice for proximal junctional kyphosis at T1–T2, and once for an epidural hematoma. The SRS-30 questionnaire indicated strong patient satisfaction, with 11 patients who would have the same procedure again if they had the same condition. Conclusions: This is the first reported series of PD patients undergoing posterior spinal fusion from T2 to the sacrum for major deformities. This study indicates that good correction of sagittal and frontal balance enables good clinical and radiologic results that remain stable over time even when complications occur.

Triple total cervical vertebrectomy for a giant cell tumor: case report.

Study Design. Case report of a triple total cervical vertebrectomy. Objective. To describe a new management for cervical tumor. Preoperative planning using arteriography, successive occlusion of both vertebral arteries, and the cervical vertebrectomy are reported. Summary of Background Data. Thoracic or lumbar complete vertebrectomy for primary malignant tumor or metastasis is a well established surgical technique. The presence of the vertebral arteries appears to have prevented the previous use of complete vertebrectomy in the cervical spine. Methods. A 25-year-old male patient who had a giant cell tumor in C6 underwent hemi-vertebrectomy. Before this surgical procedure, the ipsilateral vertebral artery was embolized. The tumor recurred locally 18 months later. Using temporary balloon occlusion of the remaining vertebral artery, an abundant collateral circulation from the cervical arteries to the vertebrobasilar territory was shown. Triple total cervical vertebrectomy from C5–C7 was then performed with double stage surgery. Results. At 2-year follow-up, the patient is tumor-free. Conclusions. Complete resection of malignant cervical vertebrae is possible if both vertebral arteries can be successively occluded, permitting complete removal of the transverse processes.