Multiple-rod constructs in adult spinal deformity surgery for pelvic-fixated long instrumentations: an integral matched cohort analysis.

PURPOSE: Multiple-rod constructs (Multi-Rod: extra rods for additional pillar support) are occasionally used in adult spinal deformity (ASD) surgery. We aimed to compare and analyze the general outcome of multi-rod constructs with a matched two-rod cohort, to better understand the differences and the similitudes. METHODS: This is a retrospective matched cohort study including patients with ASD that underwent surgical correction with long posterior instrumentation (more than five levels), pelvic fixation and a minimum 1-year follow-up. Matching was considered with demographical data, preoperative radiographical parameters, preoperative clinical status [health-related quality-of-life (HRQoL) scores] and surgical characteristics (anterior fusion, decompression, rod material, osteotomies). Postoperative radiographical and clinical parameters, as well as complications, were obtained. Univariate and multivariate analysis was performed regarding postoperative improvement, group variables comparison and parameters correlation. RESULTS: Thirty-three patients with multi-rod construct and 33 matched with a two-rod construct were selected from a database with 346 ASD-operated patients. Both groups had a significant improvement with surgical management in the radiographical and HRQoL parameters (p < 0.001). Differences between groups for the postoperative radiographical, clinical and perioperative parameters were not significant. Rod breakage was more frequent in the two-rod group (8 vs 4, p = 0.089), as well as the respective revision surgery for those cases (6 vs 1 p = 0.046). Risk factors related to revision surgery were greater kyphosis correction (p = 0.001), longer instrumentation (p = 0.037) and greater sagittal vertical axis correction (p = 0.049). CONCLUSION: No major disadvantage on the use of multi-rod construct was identified. This supports the benefit of using multi-rod constructs to avoid implant failure. These slides can be retrieved under Electronic Supplementary Material.

Cerebral ischaemia following anterior upper thoracic spinal surgery utilizing a partial manubrial resection.

PURPOSE: Firstly, to describe two cases of cerebral ischaemia complicating anterior upper thoracic spinal surgery and define the likely cause of this complication. Secondly, to describe preventative measures and the effect these have had in reducing this complication within our institution. METHODS: Firstly, a review of two cases of cerebral ischaemia complicating anterior upper thoracic spinal surgery utilizing a partial manubrial resection. Secondly, cadaveric dissections of the carotid arteries to determine the effect of neck positioning and aortic arch retraction during a simulated procedure. Thirdly, a retrospective review of 65 consecutive cases undergoing this procedure and assessment of the rate of this complication before and after the adoption of preventative measures. RESULTS: Two cases of carotid artery territory cerebral ischaemia, without radiographic evidence of carotid or cardiac pathology were identified in 50 consecutive cases prior to the implementation of preventative measures. These patients revealed fluctuating hemodynamic instability after placement of the inferior retractor. Cadaveric dissection reveals significant carotid artery traction particularly with neck extension. Since the adoption of preventative measures, no cases of cerebral ischaemia have been encountered. CONCLUSIONS: Cerebral ischaemia is a potential complication of anterior upper thoracic spinal surgery requiring retraction of the aortic arch. This most likely occurs from carotid stenosis due to aortic retraction and therefore, may be reduced by positioning the patient with neck flexion. Continuous non-invasive monitoring of cerebral saturation, as well as actively monitoring for hemodynamic instability and reduced carotid pulsation after retractor placement, allows for early detection of this complication. If detected, perfusion can be easily restored by reducing the retraction of aortic arch.

Traumatic posterior Atlanto-axial dislocation: case report of an atypical C1-C2 dislocation with an anterior arch fracture of C1.

BACKGROUND: An atypical case of a traumatic posterior C1-C2 dislocation with an anterior arch fracture of C1 is reported. A novel conservative treatment for this rare lesion is described. CASE PRESENTATION: An eighty-nine-year-old male fell off a ladder at home and presented with an acute traumatic cervical spine trauma, which we believe involved a distraction mechanism. The patient was neurologically intact; he denied any weakness, numbness or paresthesia. A preoperative CT-scan demonstrated a posterior dislocation with an anterior arch of C1 fracture. Conservative management was elected. Reduction was achieved by closed manual reduction under general anesthesia. A postoperative CT demonstrated a complete reduction of the atlanto-axial dislocation. CONCLUSION: Based on this case report and relevant literature, we present an unusual lesion of the upper cervical spine treated nonoperatively with closed manual reduction under general anesthesia. To date, there is no available consensus for the management of these lesions.

L5 pedicle subtraction osteotomy: indication, surgical technique and specificities.

PURPOSE: To evaluate the radiographic, functional outcomes, complications and surgical specificities of L5 pedicle subtraction osteotomy for fixed sagittal and coronal malalignment. METHODS: A retrospective cohort of consecutive patients with prospectively collected data. Ten patients who underwent PSO at L5 were eligible for a 2-year minimum follow-up (average, 4.0 years). Patients were evaluated by standardized upright radiographs. Preoperative and postoperative radiographies, surgical data and complications were collected. RESULTS: All surgeries were revision surgeries. The mean lumbar lordosis before surgery was - 22.5° (range, 8° to - 33°) and improved to - 58.5° (range, - 40° to - 79°). The sagittal vertical axis demonstrated a preoperative mean sagittal malalignment of 13.7 cm (range 3.5 to 20 cm), with correction to 4.6 cm postoperatively. Three patients required additional surgery at the latest follow-up for rod breakage. CONCLUSIONS: PSO of L5 can be a safe and effective technique to treat and correct fixed sagittal imbalance and provide biomechanical stability. The high complication rate mandates a careful assessment of the risk/benefit ratio of such a major surgery. Most patients are satisfied, particularly when sagittal balance is achieved.

Bisphosphonate therapy for spinal aneurysmal bone cysts.

PURPOSE: To assess the efficacy of bisphosphonate therapy in the management of spinal aneurysmal bone cysts (ABCs). METHODS: A prospective study of six consecutive patients aged between 7 and 22 years with spinal ABCs treated with pamidronate (1 mg/kg) or zoledronate (4 mg). A visual analogue scale (VAS) for pain and radiological (contrast-enhanced MRI and CT scan at 3 and 6 months, then yearly X-rays) follow-up was continued for a minimum of 6 years. RESULTS: One patient with an unstable C2/3 failed to respond to a single dose of bisphosphonate and required surgical resection and stabilisation with autologous bone grafting. Another, with a thoraco-lumbar ABC, experienced progression of neurological dysfunction after one cycle of bisphosphonate and, therefore, required surgical resection and stabilisation. In all other patients pain progressively improved and was resolved after two to four cycles (VAS 7.3-0). These patients all showed reduction in peri-lesional oedema and increased ossification by 3 months. No patients have had a recurrence within the timeframe of this study. CONCLUSIONS: Bisphosphonate therapy can be used as the definitive treatment of spinal ABCs, except in patients with instability or progressive neurology, where surgical intervention is required. Clinicians should expect a patients symptoms to rapidly improve, their bone oedema to resolve by 3 months and their lesion to partially or completely ossify by 6-12 months.

Spondylolisthesis adjacent to a cervical disc arthroplasty does not increase the risk of adjacent level degeneration.

PURPOSE: To understand whether a spondylolisthesis in the sub-axial spine cranial to a cervical disc arthroplasty (CDA) construes a risk of adjacent level disease (ALD). METHODS: A retrospective review of 164 patients with a minimum 5-year follow-up of a cervical disc arthroplasty was performed. Multi-level surgeries, including hybrid procedures, were included. Multiple implant types were included. The two inter-vertebral discs (IVD) cranial of the CDA were monitored for evidence of radiologic degeneration using the Kettler criteria. RESULTS: The rate of ALD in CDA found in this series was 17.8%, with most affecting the immediately adjacent IVD (27.4 and 7.6%, respectively p = 0.000). Pre-operative mild spondylolisthesis adjacent to a planned CDA was not found to be a risk factor for ALD within 5 years. Those with a degenerative spondylolisthesis are at higher risk of ALD (33%) than those with a non-degenerative cause for their spondylolisthesis (11%). Post-operative CDA alignment, ROM or induced spondylolisthesis do not affect the rate of ALD in those with an adjacent spondylolisthesis. Patients with ALD experience significantly worse 5-year pain and functional outcomes than those unaffected by ALD. CONCLUSIONS: A pre-operatively identified mild spondylolisthesis in the sub-axial spine cranially adjacent to a planned CDA is not a risk factor for ALD within 5 years. These slides can be retrieved under Electronic Supplementary Material.

Outcomes of the Bryan cervical disc replacement: fifteen year follow-up.

BACKGROUND: The CTDR is a technique that treats cervical disc degenerative disease. Initial shorter-term studies showed good clinical and radiological results. PURPOSE: To assess the clinical and radiological results of Bryan cervical disc replacement (Medtronic Sofamor Danek Inc., Memphis, TN) at 15-year follow-up. RESULTS: This prospective study included 20 patients who underwent 22 CTDR, comprising a single-level procedure in 14 patients and two-level procedures in six patients. The mean follow-up period was 15.5 years. The mean age at the intervention was 46.2 years (range: 26-65 years). Two patients needed re-operation for recurrence of symptoms. According to Odom's criteria, 80.0% (16 of 20 patients) had excellent outcomes, VAS for neck pain was 2.6 (0-10), for shoulder/arm pain it was 1.8 (0-7), and NDI at the final follow up was 14.9. The SF-12 PCS was 46.1, and SF-12 MCS was 51.9. Mobility was maintained in 15 of the 22 (68.2%) operated segments, range of motion (ROM) of prostheses were 9° ± 3.9° (range 4-15°). The prostheses were positioned in kyphosis in 14 of 22 levels (63.6%). There was a positive correlation between the kyphosis of the prosthesis and the occurrence of heterotopic ossification (HO), and their grade (ρ = 0.36, CI 95%[-0.68; 0.07]). HO had developed at 12 of the 22 levels (54.5%) and upper adjacent segment degeneration in 11 of 18 of patients (64.7%). All these results were not significantly different to outcomes at 8 years follow-up. CONCLUSION: In a cohort of 20 patients with 15-year clinical and radiological follow-up, the Bryan CTDR has demonstrated a sustained clinical improvement and implant mobility over time, despite a moderate progression of degenerative processes at the prosthetic and adjacent levels.

Clinical results of cervical disc replacement with the Baguera C prosthesis after two years follow-up.

We studied pain, neurological, and functional outcomes of one and two-levels cervical arthroplasties using a semi-constrained prosthesis for symptomatic cervical degenerative discopathies. Retrospective analysis of 95 patients in a multicentric registry over 2 years FU. Implant-related complications, subsequent surgery and neurological deterioration were not observed. After two years, improvement of > 20% of the NDI was observed in 81.8%, of > 20% of the neck pain in 75.5% and of 20% in arm pain in 77.6%. A > 15% QOL improvement (SF 36 questionnaire) was recorded in 76.5% (physical) and in 77,6% (mental). Greater benefits of cervical arthroplasty were observed in patients under 50 without previous surgeries and with preoperative NDI > 30%, confirming a safe and effective technique.

Intraspinal canal rod migration causing late-onset paraparesis 8 years after scoliosis surgery.

INTRODUCTION: Complete intraspinal canal rod migration with posterior bone reconstitution has never been described in the adolescent idiopathic scoliosis (AIS) population. We present an unusual but significant delayed neurological complication after spinal instrumentation surgery. CASE REPORT: A 24-year-old woman presented with lower limb weakness (ASIA D) 8 years after posterior instrumentation from T2 to L4 for AIS. CT scan and MRI demonstrated intra-canal rod migration with complete laminar reconstitution. The C-reactive protein was slightly elevated (fluctuated between 10 and 20 mg/l). Radiographs showed the convex rod had entered the spinal canal. The patient was taken into the operating room for thoracic spinal decompression and removal of the convex rod. This Cotrel-Dubousset rod, which had been placed on the convexity of the thoracic curve had completely entered the canal from T5 to T10 and was totally covered by bone with the eroded laminae entirely healed and closed. There was no pseudarthrosis. Intra-operatively, the fusion mass was opened along the whole length of this rod and the rod carefully removed and the spinal cord decompressed. The bacteriological cultures returned positive for Propionibacterium acnes. The patient recovered fully within 2 months post-operatively. CONCLUSION: We opine that the progressive laminar erosion with intra-canal rod migration resulted from mechanical and infectious-related factors. The very low virulence of the strain of Propionibacterium acnes is probably involved in this particular presentation where the rod was trapped in the canal, owing to the quite extensive laminar reconstitution.

THE GLOBAL TILT: EVALUATION OF A PARAMETER CONSIDERING THE GLOBAL SPINOPELVIC ALIGNMENT.

PURPOSE: Regarding the close interaction between the spinal balance and the pelvis orientation no parameter is routinely used to describe and to evaluate the global spinopelvic balance, taking into account simultaneously the spinal part and the pelvic part of the global alignment. The global tilt was described to analyze malalignment, considering spinal and pelvic imbalance together. From a geometrical point of view, the global tilt is the sum of the C7 vertical tilt and the pelvic tilt. The aim of this study is to evaluate the global tilt by analyzing its correlation with spinal malalignment. METHODS: A cohort of patients who underwent a lumbar pedicle subtraction osteotomy (PSO) for major sagittal malalignment was realized. All patients had preoperative and postoperative full spine EOS radiographies to measure spinopelvic parameters. The lack of lordosis was calculated after prediction of theoretical lumbar lordosis. Correlation analysis between different spinopelvic parameters, including the global tilt, was performed for preoperative and postoperative values. RESULTS: Thirty-one consecutive patients were included. All parameters were correlated with spinal malalignment but the global tilt was the most correlated parameter in preoperative (r = 0.71) and in postoperative (r = 0.78). When spinal and pelvic parameters were analyzed separately, 19% of patients presented mismatches between spine and pelvis. CONCLUSION: This study highlights the interest of a global parameter evaluating the spinal balance and the pelvic balance together. The global tilt appeared to be the most correlated parameter in this study with spinal malalignment and could be used for the interpretation of clinical series in spine surgery.

Management of a major atlanto-axial instability secondary to a lytic lesion of C2.

INTRODUCTION: Management of C1-C2 instability is very challenging, especially when tumoral lesions are involved. CASE REPORT: We present the case of a 65-year-old male, with a recently discovered small cell lung carcinoma, presenting progressive tetraparesis due to a secondary lesion involving the body of C2 with complete collapse of its anterior part and major C1-C2 instability in all planes. The patient underwent a reconstructive surgery of the upper cervical spine during two sessions. First, an emergency surgery was done by a high anterior cervical approach, where reconstruction of the body of C2 was done by an original technique using a C3 body to odontoid long screw with bone cement filling around the screw at the level of C2, and an anterior buttress plate put from C2 to C4. A posterior surgery was performed after 48 h to stabilize the spine posteriorly with C1 to C5 instrumentation. The patient recovered from his neurological symptoms, and underwent complementary adjuvant radiotherapy with chemotherapy later on. CONCLUSION: Literature is sparse on the treatment of major C1-C2 instability, especially when a secondary lesion is involved, the current case shows a successful treatment strategy with an original technique that was never described before in the literature. The patient was pain free at 1 year follow-up with a stable construct.

Cervical spine alignment following lumbar pedicle subtraction osteotomy for sagittal imbalance.

PURPOSE: The alignment of the cervical spine is of primary importance to maintain horizontal gaze and contributes to the functional outcome of patients. Cervical spine alignment after correction of major sagittal imbalance has rarely been reported in the literature. METHODS: Retrospective review of 31 consecutive patients with sagittal plane deformities operated by lumbar pedicle subtraction osteotomy. Pre-operative and 3 months post-operative full-length radiographies were analyzed for spinopelvic and cervical-specific parameters. RESULTS: There was a significant increase in lumbar lordosis (LL), thoracic kyphosis, and sacral slope. There was also a significant decrease in pelvic tilt, pelvic incidence minus LL, knee flexion and sagittal vertical axis. The cervical analysis revealed that there was no significant difference between pre- and post-operative global cervical lordosis (CL) angle and external auditory meatus (EAM) tilt. There was a significant decrease of C7 slope and distal CL, while a significant increase in occipito-C2 (OC2) angle was observed. CONCLUSION: LL restoration decreased the need of compensation at the pelvis and thoracic spine. The distal CL and C7 slope decreased because there was no need for compensation at this level after the surgery, but the proximal cervical spine takes a slightly flexed position to maintain horizontal sight. EAM tilt measures the head position toward C7, and is close to 0° even in severe cases. Changes of this parameter after surgery are insignificant, probably due to the balance between upper and lower cervical segments; when one of these segments shifts backward the other shifts forward and the result is a balanced head over C7.

Cervical spine balance: postoperative radiologic changes in adult scoliosis surgery.

PURPOSE: Cervical spine alignment interests appeared recently and relationships between the pelvis and the cervical spine have been reported but remain unclear. In this study, postoperative changes for cranial, cervical, lumbar and sagittal balance parameters have been measured in adult scoliosis surgery without major sagittal malalignment to appreciate the adaptation of the cervical spine. METHODS: Twenty-nine consecutive patients with a surgical adult degenerative scoliosis treated with a T8-T11 to iliac fusion without PSO or multiple Ponte's osteotomies had preoperative and postoperative full spine EOS radiographies to measure spino-pelvic parameters. Correlation analysis between the different parameters was performed. RESULTS: Lower cervical, lordosis, lumbar lordosis and thoracic kyphosis were increased in postoperative as no changes were observed for upper cervical lordosis. C1-C7 CL highly correlated (0.85 in preoperative and 0.87 in postoperative) with C7 slope, which highly correlated itself with global balance parameters (0.74 in preoperative and 0.71 in postoperative for CAM-PL) underlining the relationship between cervical spine alignment and global malalignment. CONCLUSIONS: Modifications of lower CL are observed, as upper CL remains constant. If no correlation was found for LL, TK and CL changes, CL appears to be highly correlated with C7 slope, which highly correlated itself with sagittal global balance parameters. C7 slope appears as a base for CL influenced by the spine global alignment.

Endovascular Embolization of a Nondominant Vertebral Artery Compressed by an Osteophyte to Prevent Recurrence of Vertebrobasilar Infarctions.

BACKGROUND: Vertebral artery compression by cervical osteophyte is a rare cause of vertebrobasilar ischemic stroke. This mechanism of stroke has been reported as the Bow Hunter syndrome defined by vertebrobasilar insufficiency because of mechanical stenosis of the vertebral artery at the cervical level triggered by head movement. The most common treatment is surgical decompression. However, in most cases, a dominant vertebral artery is involved, and its dynamic extrinsic compression is demonstrated on angiography. CASE REPORT: We report a patient with recurrent posterior circulation infarctions because of the compression of a nondominant vertebral artery by a cervical osteophyte. The dynamic angiography did not show any worsening of the vertebral stenosis by head movements but an irregularity of the vertebral artery with regard to the osteophyte compression, suggesting a direct artery wall injury. We concluded to an embolic mechanism through thrombus formation from the artery wall injury at the stenosed site. Because neither surgical decompression nor stenting was deemed to be a relevant treatment option, endovascular coil embolization of the compressed vertebral artery was performed after a clamping test to check the efficiency of the collateral circulation. The procedure was a success. During the 12-month follow-up, the patient did not have any recurrent stroke. CONCLUSIONS: In case of recurrent symptomatic extrinsic compression of a nondominant vertebral artery, endovascular embolization after a clamping test may be considered.

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.

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.

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

PURPOSE: The 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. METHODS: A 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. RESULTS: No 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. CONCLUSION: We 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.

Surgery improves pain, function and quality of life in patients with spinal metastases: a prospective study on 118 patients.

PURPOSE: There are few prospective studies on surgical outcomes and survival in patients with metastatic disease to the spine. The magnitude and duration of effect of surgery on pain relief and quality of life remains uncertain. Therefore, the aim of this clinical study was to prospectively evaluate clinical, functional, quality of life and survival outcomes after palliative surgery for vertebral metastases. METHODS: 118 consecutive patients who underwent spinal surgery for symptomatic vertebral metastases were prospectively followed up for 12 months or until death. Clinical data and data from the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire were obtained pre- and post-operatively and at regular follow-up intervals. RESULTS: Surgery was effective in achieving rapid improvement in axial and radicular pain, neurological deficit, sphincteric dysfunction and ambulatory status, with a complication rate of 26% and a 12 month mortality rate of 48%. Almost 50% of patients had complete resolution of back pain, radiculopathy and neurological deficit. Of the patients who were non-ambulant and incontinent, over 50% regained ambulatory ability and recovered urinary continence. The overall incidence of wound infection or breakdown was 6.8% and the local recurrence rate was 8.5%. There was a highly significant improvement in physical, role, cognitive and emotional functioning and global health status post-operatively. Greatest improvement in pain, function and overall quality of life occurred in the early post-operative period and was maintained until death or during the 12 month prospective follow-up period. CONCLUSION: The potential for immediate and prolonged improvement in pain, function and quality of life in patients with symptomatic vertebral metastases should be considered during the decision-making process when selecting and counselling patients for surgery.

Total vertebrectomy and spine shortening in the management of acute thoracic spine fracture dislocation: technical note and report of 3 cases.

STUDY DESIGN: Case report of 3 thoracic spine fracture-dislocations with complete spinal cord section treated by total vertebrectomy--spine shortening through a posterior approach. OBJECTIVES: To assess the usefulness and safety of this surgical technique in the treatment of acute thoracic spine fracture-dislocation. SUMMARY OF BACKGROUND: Total vertebrectomy can be used in different nontraumatic disorders. This surgical procedure has been used in the chronic phase of traumatic thoracolumbar dislocation. To our knowledge, the technique of total vertebrectomy and spine shortening in the acute phase of thoracic spine fracture dislocation has never been reported. MATERIAL AND METHODS: Three patients who suffered thoracic spine fracture-dislocation with ASIA A paraplegia underwent complete vertebrectomy and spine shortening through a posterior approach. We report technical details, clinical, and radiologic results at 24 months minimum follow-up. RESULTS: Complete vertebrectomy of the fractured vertebra involved T5 in 1 patient, T7 in another, and T10 in the third. There were no perioperative complications. At latest follow-up, fusion was obtained in all 3. Overall sagittal and coronal alignment was restored. CONCLUSIONS: Complete vertebrectomy and spinal shortening can be used in the acute phase to manage thoracic spine fracture-dislocations.

Safe working zones using the minimally invasive lateral retroperitoneal transpsoas approach: a morphometric study.

PURPOSE: The minimally invasive lateral retroperitoneal transpsoas approach is a recent technique developed for lumbar interbody fusion and discectomy. The proximity of the retroperitoneal vessels and ventral nerve roots to the surgical pathway increases the risk of injury to these anatomical structures. A precise knowledge of the regional anatomy of the lumbar plexus is required for safe passage through the psoas muscle. Preoperative examination of the axial MRI images will allow the surgeon to observe the neural structures at the operative levels and confirm that abdominal vessels do not obstruct the lateral disc space. The objective of this study was to determine the anatomic position of the ventral nerve roots and the retroperitoneal vessels in relation to the vertebral body in the degenerative spine and to delineate a safe working zone using magnetic resonance imaging (MRI). METHODS: We retrospectively evaluated lumbar spine MRI in 78 patients (from L1-L2 to L4-L5). The total number of lumbar vertebrae measured was 304 levels. Sagittal MRI sections were used to measure disc height (anterior, middle, posterior). Axial MRI sections were used to measure the sagittal and transversal vertebral endplate diameters, the overlap between ventral nerve roots and the posterior border of the lower endplate of the vertebral body, and the overlap between the retroperitoneal vessels and the anterior border of the lower endplate of the vertebral body. The safe zone was subsequently calculated. It was defined as the relative lower endplate vertebral body sagittal diameter that is anterior to the nerve root and is posterior to the retroperitoneal vessels. RESULTS: The safe working zone was 75.3% of the lower endplate of the vertebral body sagittal diameter at L1-L2, 59.5% at L2-L3, 51.9% at L3-L4 and 37.8% at L4-L5 levels. This area significantly decreases from L1-L2 to L4-L5 (p < 0.05). Compared with L1-L2, L2-L3 levels, the more anterior position of the nerve root and the more posterior position of the retroperitoneal vessels at the L4-L5 level causes a significant reduction of this area. Compared with the L3-L4 level, we observed that the safe zone decrease was simply secondary to the more anterior position of the nerve roots at the L4-L5 level. CONCLUSION: Preoperative planning and safe zone delineation are a simple method to assess the relative position of neural and vascular anatomic structures in relation to the surgical area. This method can help spine surgeons to prevent perioperative complications.