Anouar Bourghli

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.

Global analysis of sagittal spinal alignment in major deformities: correlation between lack of lumbar lordosis and flexion of the knee.

IntroductionIt has become well recognised that sagittal balance of the spine is the result of an interaction between the spine and the pelvis. Knee flexion is considered to be the last compensatory mechanism in case of sagittal imbalance, but only few studies have insisted on the relationship between spino-pelvic parameters and lower extremity parameters. Correlation between the lack of lumbar lordosis and knee flexion has not yet been established.Materials and methodsA retrospective study was carried out on 28 patients with major spinal deformities. The EOS system was used to measure spinal and pelvic parameters and the knee flexion angle; the lack of lumbar lordosis was calculated after prediction of lumbar lordosis with two different formulas. Correlation analysis between the different measured parameters was performed.ResultsLumbar lordosis correlated with sacral slope (r = −0.71) and moderately with knee flexion angle (r = 0.42). Pelvic tilt correlated moderately with knee flexion angle (r = 0.55). Lack of lumbar lordosis correlated best with knee flexion angle (r = 0.72 and r = 0.63 using the two formulas, respectively).ConclusionKnee flexion as a compensatory mechanism to sagittal imbalance was well correlated to the lack of lordosis and, depending on the importance of the former parameter, the best procedure to correct sagittal imbalance could be chosen.

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.

Sagittal alignment after single cervical disc arthroplasty.

Study Design Prospective study. Objectives To analyze the sagittal balance after single-level cervical disc replacement (CDR) and range of motion (ROM). To define clinical and radiologic parameters those have a significant correlation with segmental and overall cervical curvature after CDR. Summary of Background Data Clinical outcomes and ROM after CDR with Mobi-C (LDR, Troyes, France) prosthesis have been documented in few studies. No earlier report of this prosthesis has studied correlations between static and dynamic parameters or those between static parameters and clinical outcomes. Methods Forty patients were evaluated. Clinical outcome was assessed using the Short Form-36 questionnaire, Neck Disability Index, and a Visual Analog Scale. Spineview software (Surgiview, Paris, France) was used to investigate sagittal balance parameters and ROM. The mean follow-up was 24.3 months (range: 12 to 36 mo). Results Clinical outcomes were satisfactory. There was a significant improvement of Short Form-36, Neck Disability Index, and Visual Analog Scale scores. Mean ROM was 8.3 degrees preoperatively and 11.0 degrees postoperatively (P=0.013). Mean preoperative C2C7 curvature was 12.8 and 16.0 degrees at last follow-up (P=0.001). Mean preoperative functional spinal unit (FSU) angle was 2.3 and 5.3 degrees postoperatively (P<0.0001). Mean postoperative shell angle was 5.5 degrees. There was a significant correlation between postoperative C2C7 alignment and preoperative C2C7 alignment, change of C2C7 alignment, preoperative and postoperative FSU angle, and prosthesis shell angle. There was also a significant correlation between postoperative FSU angle and preoperative C2C7 alignment, preoperative FSU angle, change of FSU angle, and prosthesis shell angle. Regression analysis showed that prosthesis shell angle and preoperative FSU angle contributed significantly to postoperative FSU angle. Moreover, preoperative C2C7 alignment, preoperative FSU angle, postoperative FSU angle, and prosthesis shell angle contributed significantly to postoperative C2C7 alignment. No significant correlation was observed between ROM and sagittal parameters. Few correlations were found between sagittal alignment and clinical results. Conclusions CDR with this prosthesis provided favorable clinical outcomes and maintains ROM of the FSU, overall and segmental cervical alignment. Long-term follow-up will be needed to assess the effectiveness and advantages of this procedure.

Complex osteotomies vertebral column resection and decancellation

Pedicle subtraction osteotomy (PSO) is nowadays widely used to treat sagittal imbalance. Some complex malalignment cases cannot be treated by a PSO, whereas the imbalance is coronal or mixed or the sagittal imbalance is major and cannot be treated by a single PSO. The aim of this article was to review these complex situations—coronal imbalance, mixed imbalance, two-level PSO, vertebral column resection, and vertebral column decancellation, and to focus on their specificities. It wills also to evoke the utility of navigation in these complex cases.

Thoracic hemivertebra resection by posterior approach for congenital scoliosis

• To learn the approach to the lumbar vertebral body after transverse process removal, • To learn the technique for posterior approach for complete lumbar hemivertebra and adjacent discs resection, • To identify and obtain the correction goal: parallel endplates below and above the resection area, • To identify the strategy to obtain and maintain correction and fusion, • To learn the three rod technique fixation and identify its advantages.

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

Pedicle subtraction osteotomy for postoperative flat back and sagittal imbalance

Treatment of fixed sagittal imbalance involves performing spinal osteotomies. One option is to perform multiple Smith-Petersen osteotomies (SPO). Another option is to perform a pedicle subtraction osteotomy (PSO), which usually achieves about 30 to 40 of lordosis. A variant of the latter procedure is to resect the disc space above (modified PSO). The first procedure (SPO) is indicated when the spine is flexible with partial reduction of the deformity through mobile segments (mobile intervertebral disc space); the second procedure (PSO) is performed when the spine is fused with no correction of the deformity in the recumbent position [1].

Osteotomy of the spine for multifocal deformities

IntroductionWhen a deformity involves more than one area of the spine, it becomes a multifocal deformity; such a deformity could either be extending on two adjacent segments, or be two separated deformities on two non-adjacent segments.Materials and methodsThe surgical management of multifocal spinal deformities is challenging and must be done through a thorough preoperative planning where spinal and pelvic parameters should accurately be determined. Different strategies should be applied depending on the type of the multifocal deformity, the area involved, the angulation and stiffness of the spine in that area, and the presence of either a pure sagittal malalignment or a combined coronal and sagittal malalignment. This paper discusses these strategies and gives guidelines regarding the use of the different osteotomy techniques depending on each different situation that the deformity spine surgeon may encounter. For instance, where is the ideal level to perform a pedicle subtraction osteotomy (PSO) in a multifocal deformity? How does one take advantage of the remaining high discs to increase the correction without the need for a second PSO? When and where does one perform an asymmetrical PSO? When and where does one perform two PSOs? How does navigation help the spine surgeon to push the surgical limits further in these complex cases?ConclusionAll these questions about the management of multifocal deformities will be discussed and answered with technical details and concrete examples of the different situations that may be encountered.