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Introduction: Low-grade isthmic and degenerative spondylolisthesis (DS) of the lumbar spine are distinct pathologies but both can be treated with lumbar decompression with fusion. In a very large cohort, we compared patient-reported outcome in relation to the pathology and chief complaint at baseline., Methods: This was a retrospective analysis using the EUROSPINE Spine Tango Registry. We included 582 patients (age 60 ± 15 years; 65% female), divided into four groups based on two variables: type of spondylolisthesis and chief pain complaint (leg pain (LP) versus back pain). Patients completed the COMI preoperatively and up to 5 years follow-up (FU), and rated global treatment outcome (GTO). Regression models were used to predict COMI-scores at FU. Pain scores and satisfaction ratings were analysed., Results: All patients experienced pronounced reductions in COMI scores. Relative to the other groups, the DS-LP group showed between 5% and 11% greater COMI score reduction (p < 0.01 up to 2 years' FU). This group also performed best with respect to pain outcomes and satisfaction. Long-term GTO was 93% at the 5 year FU, compared with between 82% and 86% in the other groups., Conclusion: Regardless of the type of spondylolisthesis, all groups experienced an improvement in COMI score after surgery. Patients with DS and LP as their chief complaint appear to benefit more than other patients. These results are the first to show that the type of the spondylolisthesis and its chief complaint have an impact on surgical outcome. They will be informative for the consent process prior to surgery and can be used to build predictive models for individual outcome., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Incidental dural tears are common complications in lumbar spine surgery, particularly in endoscopic procedures where primary closure via suturing is challenging. The absence of a standardized approach for dural closure in endoscopic spine surgery necessitates exploring alternative techniques., Objective: This study introduces a surgical technique for dural closure utilizing fat graft and Gelfoam, offering an effective alternative to standard approaches in endoscopic spine surgery., Methods: Surgical data from patients who underwent interlaminar endoscopic discectomy or stenosis decompression at Lerdsin Hospital from October 2014 to October 2021 were analyzed., Results: Among 393 cases, dural tears occurred in 2% (8 patients). Our technique achieved successful closure in all these cases, with no incidents of cerebrospinal fluid leakage or wound complications. The majority of patients showed favorable clinical outcomes, except for one case involving concomitant nerve root injury., Conclusion: This study demonstrates that using fat graft and Gelfoam for dural closure is a simple, reliable, and safe technique, particularly effective for challenging-to-repair areas in interlaminar endoscopic lumbar spine surgery., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aimed to find a standard of the vertebra kinematics during functional weight-bearing activities in degenerative lumbar scoliosis (DLS) patients., Methods: Fifty-four patients were involved into this study with forty-two in DLS group and twelve in the control group. The three-dimensional (3D) vertebral models from L1 to S1 of each participant were reconstructed by computed tomography (CT). Dual-orthogonal fluoroscopic imaging, along with FluoMotion and Rhinoceros software, was used to record segmental vertebral kinematics during functional weight-bearing activities. The primary and coupled motions of each vertebra were analyzed in patients with DLS., Results: During flexion-extension of the trunk, anteroposterior (AP) translation and craniocaudal (CC) translation at L5-S1 were higher than those at L2-3 (9.3 ± 5.1 mm vs. 6.4 ± 3.5 mm; P < 0.05). The coupled mediolateral (ML) translation at L5-S1 in patients with DLS was approximately three times greater than that in the control group. During left-right bending of the trunk, the coupled ML rotation at L5-S1 was higher in patients with DLS than that in the control group (17.7 ± 10.3° vs. 8.4 ± 4.4°; P < 0.05). The AP and CC translations at L5-S1 were higher than those at L1-2, L2-3, and L3-4. During left-right torsion of the trunk, the AP translation at L5-S1 was higher as compared to other levels., Conclusions: The greatest coupled translation was observed at L5-S1 in patients with DLS. Coupled AP and ML translations at L5-S1 were higher than those in healthy participants. These data improved the understanding of DLS motion characteristics., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Endoscopic spine surgery (ESS) is a minimally invasive surgical technique that offers comparable efficacy and safety with less collateral damage compared to conventional surgery. To achieve clinical success, it is imperative to stay abreast of technological advancements, modern surgical instruments and technique, and updated evidence., Purposes: To provide a comprehensive review and updates of ESS including the nomenclature, technical evolution, bibliometric analysis of evidence, recent changes in the spine communities, the prevailing of biportal endoscopy, and the future of endoscopic spine surgery., Methods: We conducted a comprehensive review of the literature on ESS for the mentioned topics from January 1989 to November 2022. Three major electronic databases were searched, including MEDLINE, Scopus, and Embase. Covidence Systematic Review was used to organize the eligible records. Two independent reviewers screened the articles for relevance., Results: In total, 312 articles were finally included for review. We found various use of nomenclatures in the field of ESS publication. To address this issue, we proposed the use of distinct terms to describe the biportal and uniportal techniques, as well as their specific approaches. In the realm of technical advancement, ESS has rapidly evolved from addressing disc herniation and spinal stenosis to encompassing endoscopic fusion, along with technological innovations such as navigation, robotics, and augmented reality. According to bibliometric analysis, China, South Korea, and the USA have accounted for almost three-quarters of total publications. The studies of the biportal endoscopy are becoming increasingly popular in South Korea where the top ten most-cited articles have been published. The biportal endoscopy technique is relatively simple to adopt, as it relies on a more familiar approach, requires less expensive instruments, has a shorter learning curve, and is also well-suited for interbody fusion. The uniportal approach provided the smallest area of soft tissue dissection. While robotics and augmented reality in ESS are not widely embraced, the use of navigation in ESS is expected to become more streamlined, particularly with the emergence of recent electromagnetic-based navigation technologies., Conclusions: In this paper, we provide a comprehensive overview of the evolution of ESS, as well as an updated summary of current trends in the field, including the biportal and uniportal approaches. Additionally, we summarize the nomenclature used in ESS, present a bibliometric analysis of the field, and discuss future directions for the advancement of the field., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: The smartphone-based 6-min walking test (6WT) is an established digital outcome measure in patients undergoing surgery for degenerative lumbar disorders (DLD). In addition to the 6WTs primary outcome measure, the 6-min walking distance (6WD), the patient's distance to first symptoms (DTFS) and time to first symptoms (TTFS) can be recorded. This is the first study to analyse the psychometric properties of the DTFS and TTFS., Methods: Forty-nine consecutive patients (55 ± 15.8 years) completed the 6WT pre- and 6 weeks (W6) postoperative. DTFS and TTFS were assessed for reliability and content validity using disease-specific patient-reported outcome measures. The Zurich Claudication Questionnaire patient satisfaction subscale was used as external criterion for treatment success. Internal and external responsiveness for both measures at W6 was evaluated., Results: There was a significant improvement in DTFS and TTFS from baseline to W6 (p < 0.001). Both measures demonstrated a good test-retest reliability (β = 0.86, 95% CI 0.81-0.90 and β = 0.83, 95% CI 0.76-0.87, both p < 0.001). The DTFS exceeded the 6WD capability to differentiate between satisfied (82%) and unsatisfied patients (18%) with an AUC of 0.75 (95% CI 0.53-0.98) vs. 0.70 (95% CI 0.52-0.90). The TTFS did not demonstrate meaningful discriminative abilities., Conclusion: Change in DTFS can differentiate between satisfied and unsatisfied patients after spine surgery. Digital outcome measures on the 6WT metric provide spine surgeons and researchers with a mean to assess their patient's functional disability and response to surgical treatment in DLD., (© 2022. The Author(s).)

Purpose: To investigate whether upright magnetic resonance imaging (MRI) has a role in defining thoracolumbar spine pathology in elite gymnastics., Methods: A prospective cross-sectional observational study of National Senior and Junior Artistic gymnasts in three MRI positions (standard supine, upright flexed and extended positions). Two specialist musculoskeletal radiologists independently analysed images with neutral as a baseline with the effects of flexion and extension reported in line with Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement., Results: Forty (18 males) gymnasts aged 13-24 years with a mean (SD) of 32 (5.3) training hours per week consented with 75% showing MRI abnormalities. Degenerative disc disease (DDD) was evident in 55% participants with vertebral end plate (VEP) changes in 42.5%. Spondylolysis was present in 40% with an additional 17% showing chronic bilateral complete L5 pars defects. 23% participants demonstrated different MRI findings in upright flexion compared to neutral., Conclusion: Findings suggest a high levels of MRI abnormalities in elite gymnastics including altered disc morphology and posterior element abnormalities. High prevalence of T11/12 DDD and VEP changes reflects the thoracolumbar junction being a transition zone. Upright MRI and varying spine position offer promise for enhanced visualisation of posterior element abnormalities., (© 2021. The Author(s).)

Objective: Recurrent lumbar disc herniation (LDH) is the most frequent reason for reoperation after lumbar microdiscectomy. While several risk factors for recurrent LDH have been well-described, the effect of age on recurrence remains unclear, especially concerning the timing of recurrent LDH., Methods: From a prospective registry, we identified all patients who underwent tubular microdiscectomy for LDH. Recurrent LDH was defined as reoperation for LDH at the same index level and side. The associations among age and incidence of recurrent LDH as well as on time to recurrent LDH were statistically evaluated using multivariable analysis of covariance, linear regression, and Cox proportional hazards modelling., Results: Of the 3013 patients who underwent surgery for LDH, 166 (5.5%) had to undergo reoperation due to LDH recurrence. Uni- and multivariable analysis revealed no influence of age on the incidence of recurrent LDH (both p > 0.05). Linear regression indicated earlier reoperation in older patients, both with (β = -0.248) and without (β = -0.374) correction for confounders (both p < 0.05). An additional survival analysis found that patients aged over 35 years had recurrent LDH significantly earlier (hazard ratio 0.617, p = 0.013)., Conclusion: In an analysis of a large prospective database of patients undergoing microdiscectomy for lumbar disc herniation, we found that younger patients do not have a higher reoperation probability than their older counterparts, even after correcting for multiple confounders. However, older patients tend to experience recurrent LDH significantly earlier after the index surgery compared to younger patients.

Purpose: The positive association between low back pain and MRI evidence of vertebral endplate bone marrow lesions, often called Modic changes (MC), offers the exciting prospect of diagnosing a specific phenotype of chronic low back pain (LBP). However, imprecision in the reporting of MC has introduced substantial challenges, as variations in both imaging equipment and scanning parameters can impact conspicuity of MC. This review discusses key methodological factors that impact MC classification and recommends guidelines for more consistent MC reporting that will allow for better integration of research into this LBP phenotype., Methods: Non-systematic literature review., Results: The high diagnostic specificity of MC classification for a painful level contributes to the significant association observed between MC and LBP, whereas low and variable sensitivity underlies the between- and within-study variability in observed associations. Poor sensitivity may be owing to the presence of other pain generators, to the limited MRI resolution, and to the imperfect reliability of MC classification, which lowers diagnostic sensitivity and thus influences the association between MC and LBP. Importantly, magnetic field strength and pulse sequence parameters also impact detection of MC. Advances in pulse sequences may improve reliability and prove valuable for quantifying lesion severity., Conclusions: Comparison of MC data between studies can be problematic. Various methodological factors impact detection and classification of MC, and the lack of reporting guidelines hinders interpretation and comparison of findings. Thus, it is critical to adopt imaging and reporting standards that codify acceptable methodological criteria. These slides can be retrieved under Electronic Supplementary Material.

Purpose: Microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is an advantageous method for treating lumbar degenerative disease; however, some patients show contralateral radiculopathy postoperatively. This study aims to investigate its risk factor., Methods: A total of 130 cases who underwent microendoscopy-assisted MIS-TLIF at L4-5 level were divided into symptomatic and asymptomatic groups according to the presence of postoperative contralateral radiculopathy. Both preoperative and postoperative radiographic parameters, as well as their changes were compared between the two groups, including lumbar lordosis (LL), surgical segmental angle (SSA), disc height (DH), contralateral foramen area (CFA) and contralateral canal area (CCA). Screw breach on contralateral L4 pedicle and decompression method (ipsilateral or bilateral canal decompression through unilateral route) were also analyzed as potential risk factors. Receiver operating characteristic (ROC) curve was drawn for the risk factor to determine the optimal threshold for predicting postoperative contralateral radiculopathy. Besides, clinical outcome assessment, involving Visual Analog Score (VAS) for back and leg, Japanese Orthopaedics Association Score (JOA) and Oswestry Disability Index (ODI), was also compared between the two groups before surgery and at final follow-up (at least 3 months after the surgery for asymptomatic patients or final treatments of contralateral radiculopathy for symptomatic cases)., Results: Postoperative contralateral radiculopathy occurred in 11 (8.5%) of the 130 patients. Both preoperative and postoperative CFA as well as its change were significantly decreased in symptomatic group compared with asymptomatic group (all P < 0.05). For the remaining four parameters (LL, SSA, DH, CCA), their preoperative, postoperative and change values showed no statistical difference between the two groups (all P > 0.05). Neither screw breach nor decompression method revealed statistical association with this complication (both P > 0.05). Based on ROC curve, the optimal threshold of preoperative CFA was 0.76 cm 2 . At final follow-up, significant improvement in VAS (back and leg), JOA and ODI was observed in both groups compared with preoperative baseline (all P < 0.05), while no difference was found between the two groups (all P > 0.05)., Conclusions: Preoperative contralateral foramen stenosis is the risk factor of contralateral radiculopathy following microendoscopy-assisted MIS-TLIF. If preoperative CFA at L4-5 level is not larger than 0.76 cm 2 , prophylactic measures, including both indirect and direct decompression of contralateral foramen, are recommended.

Purpose: The classical spinopelvic fixation includes 1 iliac screw on each side. The purpose of this study is to specify the indications of the "dual iliac screw" (DIS) construct, i.e., when to put 2 iliac screws on each side, to describe its biomechanical advantages, and to define its related technical aspects., Methods: A primary search on Medline through PubMed distribution was performed, with the use of the terms "pelvic fixation" or "spinopelvic" or "lumbo-iliac" and the terms "dual iliac screw" or "double iliac screw." English papers corresponding to the inclusion criteria were analyzed regarding the specific indications of the DIS construct and its surgical technique and advantages., Results: Eleven papers were identified according to the research criteria and included in this review. Three main indications were identified for the DIS technique according to three types of pathologies: in adult deformities when a long construct is needed in an osteoporotic patient or when correction requires three-column osteotomy of the sacrum; in trauma when a U-shaped fracture-dislocation of the sacrum is involved; in sacral tumors when a sacrectomy is performed or when destructive metastatic lesions of the sacrum require palliative surgical treatment. Biomechanically, the DIS technique proved to have higher construct stiffness in terms of compression and torsion., Conclusion: In specific cases, affecting different areas of spinal diseases, the DIS technique is more advantageous, when compared to the "single iliac screw" version, as it would provide a stronger and safer fixation at the base of the spinopelvic construct. These slides can be retrieved under Electronic Supplementary Material.

Purpose: The objective of this paper was to compare the reoperation rates, timing and causes between decompression alone and decompression plus fusion surgeries for degenerative lumbar diseases through a systematic review of the published data., Methods: A search of the literature was conducted on PubMed/MEDLINE, EMBASE and the Cochrane Collaboration Library. Reports that included reoperations after decompression alone and/or decompression plus fusion surgeries were selected using designed eligibility criteria. Comparative analysis of reoperation rates, timing and causes between the two surgeries was conducted., Results: Thirty-two retrospective and three prospective studies were selected from 6401 papers of the literature search. The analysis of data reported in these studies revealed that both surgeries resulted in similar reoperation rates after the primary surgery. However, majority of reoperations following the fusion surgeries were due to adjacent-segment diseases, and following the decompression alone surgeries were due to the same-segment diseases. Reoperation rates were not found to decrease in patients operated more recently than those operated in early times., Conclusions: Reoperation rates were similar following decompression alone or plus fusion surgeries for degenerative lumbar diseases. However, different underlying major causes exist between the two surgeries. There is no evidence showing that the reoperation rate has a trend to decline with newer surgical techniques used. The exact mechanisms of reoperation after both surgeries are still unclear. Further researches are necessary to investigate the mechanisms of reoperation for improvement of surgical techniques that aim to delay or prevent reoperation after lumbar surgery. These slides can be retrieved under Electronic Supplementary Material.

Purpose: The purpose of this study is to evaluate the feasibility and the safety of a new skin incision for minimally invasive anterior lumbar interbody fusion (ALIF): the perinavel incision., Methods: Demographic and clinical data from patients who underwent ALIF with the perinavel incision were collected. Indications to surgery, preoperative symptoms, radiological data, number of treated levels, intraoperative and early postoperative complications and wound-related problems were analysed., Result: Ninety-seven patients underwent ALIF with this new skin incision. One hundred fifty-seven levels were treated (mean 1.7 level per patient) being L4-L5 the most frequently treated. Intraoperative complications were represented only by the venous injury with a rate of 3.09% (3 cases). Postoperative complications were all linked to skin incision issues: a case of wound dehiscence and a case of superficial infection. No case of skin necrosis occurs at 3-month follow-up., Conclusions: In this paper, the perinavel skin incision was demonstrated to be as safe as traditional approaches for ALIF. Furthermore, with this incision it is possible to perform multilevel (L3-S1) ALIF, which means a good option in minimally invasive surgery as well as revision surgery. These slides can be retrieved under Electronic Supplementary Material.

Purpose: The goals of this paper are to assess the ionizing radiation exposure to the patients during thoracic and lumbar spinal fusion using a new intraoperative 3D imaging system and to evaluate the factors that could explain the variability in the observed doses., Method: We retrospectively reviewed 97 patients who underwent posterior instrumented thoracic and/or lumbar spinal fusion from December 2013 to November 2014. Primary data were the total dose area product (total DAP, Gy cm 2 ) and total skin dose (total SD, mGy). Influence of different variables (patient characteristics, surgical technique, and intraoperative imaging system parameters) that could influence patients' exposure was analyzed., Results: Radiation dose imparted to patients depended on four parameters including acquisition protocol, surgical technique, patient's BMI and operative time. Minimally invasive surgery (MIS) resulted in twofold higher dose for patients, compared to open surgery. The use of low dose acquisition protocols reduced patient exposure by a factor three., Conclusion: Patient exposure was highly variable. Four parameters were found to explain about 68% of its variance when using a multi-axis robotic C-arm system. MIS technique (with navigation or not) as well as the acquisition protocol dramatically increases the radiation dose for patients. These results show the necessity to develop specific strategies adapted to patients and surgical procedures.

Purpose: Postoperative spinal epidural hematoma (PSEH) is one of the most hazardous complications after spine surgery. A recent study has reported that a ≥50 mmHg increase in systolic blood pressure after extubation was a significant risk factor for symptomatic PSEH. In this paper, the impact of hypertension on PSEH occurrence was investigated., Methods: Among a total of 2468 patients who underwent single level microscopic posterior decompression surgery for lumbar spinal stenosis in a single institute, 15 (0.6%) received evacuation surgery for PSEH. Those 15 patients were investigated statistically compared with a randomly selected control group (n = 46) using the Mann-Whitney U test and multiple logistic regression analysis., Results: The univariate analysis showed that there were no significant differences in age, gender, BMI, pre-operative anti-coagulant usage, intraoperative blood loss, operation time, and the rate of patients who received pre-operative hypertension treatment. However, there were significant differences in the rate of patients who showed high blood pressure at admission (66.7 vs 6.5%) and >50 mmHg increases in blood pressure after extubation (53.3 vs 17.4%) in the univariate analysis. Moreover, postoperatively, there was a statistical difference in the amount of post-operative drainage. Multiple logistic regression analysis showed that high blood pressures at admission and poor postoperative drainage were the essential risk factors., Conclusions: Our results demonstrate that the pre-operative high blood pressure value was the most essential risk factor for PSEH, although there was no difference in the preoperative hypertension treatment. Consequently, management of pre-operative blood pressure and post-operative drainage will be crucial for preventing PSEH.

Purpose: This paper aims to describe the rare post-operative complication of a lymphocele formation after lateral lumbar interbody fusion., Methods: The patient in this case was a 76-year-old lady with a 10 year history of low back pain and neurogenic claudication. She had previously underwent multiple spine surgeries for her condition. She presented to our institution for a recurrence of her low back pain and right anterior thigh pain. She then underwent surgery in two stages; first, a mini-open lateral interbody fusion at L3/4 and L4/5; second, posterior instrumentation of T3 to S1 with sagittal spinal deformity correction., Results: The patient recovered uneventfully in the initial post op period and was discharged within 8 days. However, she developed abdominal distension and discomfort 6 months after surgery. MRI and CT scan of her abdomen showed a retroperitoneal fluid collection compressing her left ureter, resulting in hydroureter and hydronephrosis. She was managed with a CT-guided drainage of the fluid collection. Fluid analysis was consistent with a lymphocele. Since the procedure, the patient has been asymptomatic for 2 years., Conclusions: Delayed lymphocele formation is a potential complication of lateral lumbar interbody fusion. When present, it can be managed conservatively with good results. This case suggests that surgeons should have a low threshold to investigate for a lymphocele development post-anterior or lateral lumbar spine surgery. The authors recommend the placement of a post surgical retroperitoneal drain, as it might assist in the early detection of a lymphocele formation.

Objective: The goal of this paper was to describe how endoscope-assisted oblique lumbar interbody fusion (OLIF) could remove huge lumbar disc herniation (HLDH) manifested with cauda equina syndrome (CES)., Methods: In this study, the authors made an attempt to treat CES with a direct endoscopic decompression through the OLIF corridor and performed OLIF in two patients with HLDH., Results: Two patients with HLDH were successfully treated using OLIF with spinal endoscopic discectomy. We achieved direct ventral decompression by removal of herniated disc fragments located beyond the posterior longitudinal ligament (PLL). All preoperative symptoms in two patients improved postoperatively., Conclusions: Endoscope-assisted oblique lumbar interbody fusion (OLIF) could successfully achieve neural decompression without additional posterior decompression in CES and could be used as an alternative treatment in well selected cases.

Introduction: Pelvic fixation via iliac screws is a crucial technique in stabilizing metastatic lumbosacral deformity. MIS iliac screw fixation avoids complications of an open approach and is a viable palliative option in treating patients with painful instability and advanced disease, unsuited for major reconstruction. In this paper we describe the use of MIS iliac screw fixation in treatment of painful metastatic LSJ deformity, highlighting our treatment rationale, selection criteria, technical experience and outcomes., Methods: Five patients with lumbosacral metastatic deformity who underwent MIS lumbopelvic stabilization using iliac screws were prospectively studied. Patients had severe axial back pain in erect posture with significant resolution when supine. All patients had advanced disease with unfavorable tumor scores for major spinal reconstruction., Results: Mean cohort age was 62 years. Median pre-op SIN and Tokuhashi scores were 13 and 9, respectively. All patients were instrumented successfully without conversion to open technique. Mean preoperative and postoperative Cobb angle was 11° and 5.4°, respectively. There were no neurological deficits or wound complications postop. Postoperative CT scans showed no iliac screw and sacroiliac joint bony violation. Mean time for commencement of adjuvant therapy was 2.8 weeks. Average follow-up was 13.2 months. No screw breakage, wound complication, symptomatic implant prominence and SI joint pain were noted at last follow-up., Conclusion: MIS iliac screw fixation is feasible, reproducible and can be employed without complications in metastatic spine. This opens a new avenue of surgical management for metastatic lumbosacral disease patients, who otherwise may be inoperable and provide better soft tissue control and earlier postoperative adjuvant treatment opportunity.

Purpose: Several papers examined the vascular anatomy of the lumbosacral region using cadavers with angiography. However, few reports used CT angiography, and discussion on variations of fourth lumbar, fifth lumbar, and lumbar branch of iliolumbar arteries were limited. To clarify the vascular variations around the lower lumbar spine including the lumbosacral region, particularly at the posterior elements, we performed anatomical analysis using computed tomography (CT)., Methods: Extra-osseous arteries surrounding the lumbar spine including the lumbosacral region were evaluated by two orthopedic surgeons independently, using 323 consecutive abdominal contrast-enhanced multi-planner CT scans that were taken for surgical plans in colon cancer patients. Subjects were 204 men and 119 women, whose ages ranged from 15 to 89 years (mean 66.5)., Results: Each segmental artery was visible at the L1-4 spinal levels, running from the vertebra through the lamina in 91.0 % on the right side, in 90.7 % on the left side, while it was visible in 4.6 % on the right side, in 8.7 % on the left side at the L5 level. The extra-osseous arterial supply to the L5 lamina was basically provided by two vessels on each side. One was mostly derived from the L4 segmental artery (right: 92.6 %; left: 92.0 %) that was distributed around the superior articular process, the other was derived from the iliolumbar artery (right: 62.9 %; left: 55.7 %) that was distributed around the inferior articular process through the lamina. There were mainly four combination patterns of those arteries. These combinations, which had been considered as regular patterns in textbooks, were observed in approximately 50 % (right: 55.7 %; left: 48.6 %) of patients., Conclusion: Various distributions of arteries around the lower spine were identified.

Purpose: This paper is to evaluate the efficacy and safety of transforaminal lumbar interbody fusion (TLIF) using unilateral pedicle screws along with contralateral translaminar facet joint screw (UPS+TFS) fixation in comparison with the method using bilateral pedicle screws fixation (BPS) in degenerative lumbar diseases., Methods: Forty patients with single-level lumbar diseases were divided into two groups randomly. One group was treated by TLIF with BPS fixation while the other group was treated by the new technique with UPS+TFS fixation. The preoperative and postoperative ODI, JOA, VAPS scores, mean operation time, mean operation blood loss, fusion rate and complications were collected for comparison under two surgical methods. In terms of complications, only two cases of superficial infection in the BPS group and one case of urinary tract infection in the other group was found., Results: The mean operation time and blood loss was significantly less in UPS+TFS group than in BPS group. The preoperation and postoperative ODI, JOA and VAPS at the intervals of 6 weeks, 3, 6 months and 1 year between the BPS and UPS+TFS group showed no significant disparities. Only one patient in UPS+TFS group was not fused with pseudoarthrosis formation., Conclusions: The clinical efficacy and safety of TLIF with UPS+TFS fixation were comparable to BPS fixation; however, the soft tissue injury and the corresponding operation cost were reduced with unilateral pedicle screw plus translaminar facet screw fixation.

Purpose: Surgery of adult scoliosis was based upon coronal plane radiographical analysis using Cobb angle measurements, but recently it has been demonstrated that sagittal spinopelvic alignment plays a critical role in determining the final outcome. The aim of this paper is to compare the clinical and radiological results of 81 patients affected by adult scoliosis, treated with short or long fusions, and followed for 2-5 year follow-up., Materials and Methods: 81 patients affected by degenerative lumbar scoliosis managed by posterior-only surgery were retrospectively evaluated. Fifty-seven patients underwent to a short fusion procedure, while 24 had a long fusion. Clinical and radiographic coronal and sagittal spinopelvic parameters were compared between the two groups., Results: Coronal Cobb angle was 24° preoperatively and passed to 12° in the short fusion group, while changed from 45° to 10° in the long fusion group. Lumbar lordosis was 45° preoperatively and 60° at final follow-up in the short fusion group passed from 24° to 55° in the long fusion group. Sacral slope passed from 25° to 45° in the short fusion group, while from 10° to 40° in the long fusion group. Pelvic tilt passed from 24° to 13° in the short fusion group, and from 28° to 23° in the long fusion group., Conclusion: Surgical treatment of degenerative lumbar scoliosis improved balance and alignment of the spine, and also the coronal plane in terms of Cobb angle. These results were associated to a consistent clinical improvement and an acceptable rate of complications.

Purpose: Adamantinoma is a low-grade primary malignant bone tumour with slow growth and local recurrence. Its occurrence in the spine is extremely rare, particularly with multilevel involvement. This paper wants to present the first case involving a patient with recurrent thoracolumbar spinal adamantinoma, who underwent a successful three-level spondylectomy for en bloc resection., Methods: A 24-year-old man with osteolytic masses of T11 and T12 vertebral bodies was performed curettage by a posterior approach in 2008. The pathology report showed the excised neoplasm was a rare adamantinoma. This patient underwent a tumorectomy again because of its local recurrence nearly 3 years later. In 2012, it was unfortunately revealed that the excised tumour had relapsed and had spread to the L1 vertebral body. Due to its repeated recurrence and aggressive lesion, total en bloc spondylectomy (TES) for this malignant tumour was thought to be the best option for preventing repeated recurrence and possible cure. TES for T11-L1 thoracolumbar spine was performed and spinal reconstruction was completed with instrumentation and a titanium mesh cage through a one-stage single posterior approach., Results: After three-level TES, neurological deficits of the patient demonstrated good recovery and no evidence of adamantinoma recurrence or deformity was found at 2-year follow-up., Conclusions: This is the first case involving multilevel thoracolumbar spinal adamantinoma with repeated recurrence to be successfully treated by three-level TES by a single posterior approach.

Purpose: Purpose of this paper is to evaluate the primary stability of a new approach for facet fixation the so-called Facet Wedge (FW) in comparison with established posterior fixation techniques like pedicle screws (PS) and translaminar facet screws (TLS) with and without anterior cage interposition., Methods: Twenty-four monosegmental fresh frozen non-osteoporotic human motion segments (L2-L3 and L4-L5) were tested in a two-arm biomechanical study using a robot-based spine tester. Facet Wedge was compared with pedicle screws and translaminar screws as a stand-alone device and in combination with an anterior fusion cage., Results: Pedicle screws, FW and translaminar screws could stabilize an intact motion segment effectively. Facet Wedge was comparable to PS for lateral bending, extension and flexion and slightly superior for axial rotation. Facet Wedge showed a superior kinematic capacity compared to translaminar screws., Conclusions: Facet Wedge offers a novel posterior approach in achieving primary stability in lumbar spinal fixation. The results of the present study showed that the Facet Wedge has a comparable primary stability to pedicle screws and potential advantages over translaminar screws.

Purpose: This paper reports the authors' 19 years experience with pediatric intrasacral rod fixation., Methods: After insertion of two cannulated screws in S1 with and an original template guiding them into the anterior third of the endplate, two short fusion rods were inserted into the sacrum according to Jackson's technique distally to S3. In neuromuscular scoliosis, pelvic obliquity was reduced by connecting the proximal and distal constructs, distraction or compression, and in situ rod bending. In children with high-grade spondylolisthesis, lumbosacral kyphosis was reduced by rotation of the sacrum and in situ bending., Results: There were no direct neurological or vascular injuries. The main complication was infection (7%). No pseudarthrosis or significant loss of correction at the lumbosacral junction was observed during follow-up., Conclusions: Intrasacral rod fixation appears to be safe and reliable for lumbopelvic fusion in pediatric patients.

Introduction: Gunshot wounds are one of the commonest causes of spinal injury. Management of these patients differs from other blunt trauma injuries to the spine. We present a case of a gunshot wound to the lumbar spine that occurred in 1985 which was treated non-operatively., Methods: In the last 10 years, the patient was admitted multiple times for confusion and lead toxicity with blood levels over 100 μg/dl. Inpatient chelation therapy was implemented. After multiple recommendations for surgery, the patient agreed to have as much of the bullet removed as possible. The patient successfully underwent decompression and fusion from both anterior and posterior approaches. Lead levels subsequently declined., Conclusion: The purpose of this paper is to show a case of a gunshot wound to the spine that ultimately caused plumbism and required surgery. Technical aspects of the surgery are described as well as pre- and post-procedural imaging. Recommendations for the general management of spine gunshot wounds are also described.

Introduction: Aging spine is characterized by facet joints arthritis, degenerative disc disease, bone remodeling and atrophy of extensor muscles resulting in a progressive kyphosis of the lumbar spine., Objective: The aim of this paper is to describe the different compensatory mechanisms for patients with severe degenerative lumbar spine., Material and Methods: According to the severity of the imbalance, three stages are observed: balanced, balanced with compensatory mechanisms and imbalanced. For the two last stages, the compensatory mechanisms permit to limit the consequences of loss of lumbar lordosis on global sagittal alignment and therefore contribute to keep the sagittal balance of the spine., Results: The basic concept is to extend adjacent segments of the kyphotic spine allowing for compensation of the sagittal unbalance but potentially inducing adverse effects., Conclusion: Finally, we propose a three-step algorithm to analyze the global balance status and take into consideration the presence of the compensatory mechanisms in the spinal, pelvic and lower limb areas.

Purpose: The AO Spine Classification Group was established to propose a revised AO spine injury classification system. This paper provides details on the rationale, methodology, and results of the initial stage of the revision process for injuries of the thoracic and lumbar (TL) spine., Methods: In a structured, iterative process involving five experienced spine trauma surgeons from various parts of the world, consecutive cases with TL injuries were classified independently by members of the classification group, and analyzed for classification reliability using the Kappa coefficient (κ) and for accuracy using latent class analysis. The reasons for disagreements were examined systematically during review meetings. In four successive sessions, the system was revised until consensus and sufficient reproducibility were achieved., Results: The TL spine injury system is based on three main injury categories adapted from the original Magerl AO concept: A (compression), B (tension band), and C (displacement) type injuries. Type-A injuries include four subtypes (wedge-impaction/split-pincer/incomplete burst/complete burst); B-type injuries are divided between purely osseous and osseo-ligamentous disruptions; and C-type injuries are further categorized into three subtypes (hyperextension/translation/separation). There is no subgroup division. The reliability of injury types (A, B, C) was good (κ = 0.77). The surgeons' pairwise Kappa ranged from 0.69 to 0.90. Kappa coefficients κ for reliability of injury subtypes ranged from 0.26 to 0.78., Conclusions: The proposed TL spine injury system is based on clinically relevant parameters. Final evaluation data showed reasonable reliability and accuracy. Further validation of the proposed revised AO Classification requires follow-up evaluation sessions and documentation by more surgeons from different countries and backgrounds and is subject to modification based on clinical parameters during subsequent phases.

Purpose: The main aim of this paper was to report reproducible method of lumbar spine access via a lateral retroperitoneal route., Methods: The authors conducted a retrospective analysis of the technical aspects and clinical outcomes of six patients who underwent lateral multilevel retroperitoneal interbody fusion with psoas muscle retraction technique. The main goal was to develop a simple and reproducible technique to avoid injury to the lumbar plexus., Results: Six patients were operated at 15 levels using psoas muscle retraction technique. All patients reported improvement in back pain and radiculopathy after the surgery. The only procedure-related transient complication was weakness and pain on hip flexion that resolved by the first follow-up visit., Conclusions: Psoas retraction technique is a reliable technique for lateral access to the lumbar spine and may avoid some of the complications related to traditional minimally invasive transpsoas approach.

Purpose: Minimally invasive or "minimal access surgery" (MAS) is being utilized with increasing frequency to reduce approach-related morbidity in the lumbar spine. This paper describes our minimal access technique for posterior bilateral transforaminal lumbar interbody fusion (TLIF) and spinal instrumentation in a patient with high-grade spondylolisthesis grade (Myerding Grade III) with 5-year follow-up., Methods: A 24-year-old lady presented with mechanical back pain and left leg L5 radiculopathy. On examination, she was a thin lady with an obvious step deformity in the lower lumbar spine and otherwise, a normal neurological examination. Imaging showed a grade III isthmic L5-S1 spondylolisthesis with foraminal stenosis and focal kyphotic alignment of 20° [slip angle (SA) = 70°]. Conservative measures had failed, and a decision was made to proceed with a MAS-TLIF approach., Results: The estimated blood loss was less than 100 ml, operating time 150 min, and post-operative hospital stay was 4 days. Post-operatively the patient had significant improvement of back and radicular pain. Improvement in ODI was substantial and sustained at 5 years. A solid fusion was achieved at 8 months. The slip percentage improved from 68 % (pre-op) to 28 % (post-op) and the focal alignment to 20° lordosis (SA = 110°)., Conclusions: A MAS approach for selected patients with a mobile high-grade spondylolisthesis is feasible, safe and clinically effective, with the added benefit of reduced soft-tissue disruption. Our result of this technique suggests that the ability to correct focal deformity, and achieve excellent radiographic and clinical outcome is similar to the open procedure.

Introduction: Surgery for lumbar spinal stenosis (LSS) is today the most frequently performed procedure in the adult lumbar spine. Long-term benefit of surgery for LSS is well documented both in randomized and in non-randomized trials. In this paper, we present the results from laminarthrectomy as an alternative surgical approach, which have theoretical advantages over other approaches. In this study, we wanted to study the clinical and radiological results of laminarthrectomy. Dural sac cross-sectional areal (DSCSA) is an objective method to quantify the degree of central stenosis in the spinal canal, and was used to measure whether we were able to achieve an adequate decompression of the spinal canal with laminarthrectomy as a surgical approach., Materials and Methods: All patients operated on with this approach consecutively in the period 1 January 2008 to 31 March 2009 were included in the study. All perioperative complications were noted. Clinical results were measured by means of a questionnaire. The patients that agreed to attend the study had an MRI taken of the operated level. DSCSA before and after surgery of the actual level were measured by three observers. We then performed a correlation test between increase of area and clinical results. We also tested for inter- and intra-observer reability., Results: Fifty-six laminarthrectomy were performed. There were 17% complications, none of them were life-threatening or disabling. 46 patients attended the study and answered the questionnaire. Thirty-four patients (83%) reported clinical improvement, whereas six (13%) patients reported no improvement, and two (4%) patients reported that they were worse. Mean ODI was 23.0. Mean EQ-5D was 0.77. Mean VAS-score for back-pain was 3.1 and mean VAS-score for leg-pain was 2.8. Mean DSCSA were measured to 80 mm(2) before surgery and 161 mm(2) after surgery. That gave an increase of DSCSA of 81 mm(2) (101%). We found a significant positive correlation between increase of area and clinical results. We also found consistent inter- and intra-observer reability., Discussion: In this study, the clinical results of laminarthrectomy were good, and comparable with other reports for LSS. The rates of complications are also comparable with other reports in spinal surgery. A significant increase in the spinal canal diameter was achieved. Within the limitations a retrospective study gives, we conclude that laminarthrectomy seems to be a safe and effective surgical approach for significant decompressing the adult central spinal canal, and measurement of DSCSA, before and after surgery seems to be a good way to quantify the degree of decompression.

Purpose: The goal of this study was to determine which paraspinal approach provided a better transverse screw angle (TSA) for each vertebral level in lower lumbar surgery., Methods: Axial computed tomography (CT) images of 100 patients, from L3 to S1, were used to measure the angulation parameters, including transverse pedicle angle (TPA) and transverse cleavage plane angle (TCPA) of entry from the two approaches. The difference value between TCPA and TPA, defined as difference angle (DA), was calculated. Statistical differences of DA obtained by the two approaches and the angulation parameters between sexes, and the correlation between each angulation parameter and age or body mass index (BMI) were analyzed., Results: TPA ranged from about 16° at L3 to 30° at S1. TCPA through the Wiltse's and Weaver's approach ranged from about -10° and 25° at L3 to 12° and 32° at S1, respectively. The absolute values of DA through the Weaver's approach were significantly lower than those through the Wiltse's approach at each level. The angulation parameters showed no significant difference with sex and no significant correlation with age or BMI., Conclusions: In the lower lumbar vertebrae (L3-L5) and S1, pedicle screw placement through the Weaver's approach may more easily yield the preferred TSA consistent with TPA than that through the Wiltse's approach. The reference values obtained in this paper may be applied regardless of sex, age or BMI and the descriptive statistical results may be used as references for applying the two paraspinal approaches.

Background: Transforaminal epidural injection of steroids is used to treat lumbar radicular pain. However, there are only a few well-designed randomized, controlled studies on the effectiveness of steroid injection., Study Design: Hence, this study aims to assess the effectiveness of steroid injection to treat lumbar radicular pain using a meta-analysis of transforaminal epidural injection therapy for low back and lumbar radicular pain. The comparison was based on the mean difference in the Visual Analogue Score (VAS) and Oswestry Disability Index (ODI) from baseline to the specified followed up., Methods: The available literature of lumbar transforaminal epidural injections in managing low back and radicular pain was reviewed. Data sources included relevant literature of the English language identified through searches of PubMed and EMBASE from 1966 to 2009, and manual searches of the bibliographies of known primary and review articles. Finally, the search included the Current Controlled Trials Register and the Cochrane Database of Controlled Trials., Results: The initial search identified 126 papers. After screening, five randomised controlled trials (RCTs) were studied for analysis and only three of these had followed-up patients systematically with pain and disability outcome scores to 3 months and of these, only one had follow up to 12 months. A total of 187 patients ('treatment group' receiving local anaesthetic/steroid injection) were compared with 181 patients ('control' group, receiving local anaesthetic only or saline injection). Improvement in pain (standardised mean difference in VAS 0.2 in favour of 'treatment'; 95%CI: -0.41 to 0.00, p = 0.05, I squared 0%) but not disability (standardised mean difference in ODI 0; 95%CI: -0.21 to 0.20, p = 0.99, I squared 0%) was observed between 'treatment' and 'control' groups; these differences were not significant. Additionally, the one study following patients to 12 months did not find any significant difference in VAS and ODI between treatment and control groups., Conclusion: The current meta-analysis shows that transforaminal epidural steroid injections, when appropriately performed, should result in an improvement in pain, but not disability. The three RCTs that followed patients to 3 months (and the single study to 12 months) have found no benefit by the addition of steroids. The limitations of this study include the paucity of the available literature.

Introduction: Treatment of spine imbalance by posterior osteotomy is a valuable technique. Several surgical techniques have been developed and proposed to redress the vertebral column in harmonious kyphosis in order to recreate correct sagittal alignment. Although surgical techniques proved to be adequate, preoperative planning still is mediocre. Multiple suggestions have been proposed, from cutting tracing paper to ingenious mathematical formulas and computerised models. The analysis of the pelvic parameters to try to recover the initial shape of the spine before the spine imbalance occurred is very important to avoid mistakes during the osteotomy planification., Material and Method: The authors proposed their method for the osteotomy planning paying attention to the pelvic, and spine parameters and in accordance with Roussouly's classification. The pre operative planning is based on a full-body X-ray including the spine from C1 to the femoral head and the first 10 cm of the femur shaft. Using all the balance parameters provided, a formula name FBI is proposed. Calculation of the osteotomy is basic goniometry, the midpoint of the C7 inferior plateau (point a) is transposed horizontally on the projected future C7 plumb line (point b) crossing posterior S1 plateau on a sagittal X-ray. These are the first two reference points. A third reference point is made on the anterior wall of the selected vertebra for osteotomy at mid height of the pedicle (point c) mainly L4 vertebra. These three points form a triangle with the tip being the third reference point. The angle represented by this triangle is the theoretical angle of the osteotomy. Two more angles should be measured and eventually added. The femur angulation measured as the inclination of the femoral axis to the vertical. And a third angle named the compensatory pelvic tilt to integrate the type of pelvis. If the pelvic tilt is between 15 and 25° or is higher than 25° you must add 5 or 10°, respectively. This compensatory tilt is based on a clinical analysis of operated patients., Results: This planification was applied in a retrospective study of 18 patients and showed why in some cases improper correction was performed and prospectively in 8 cases with good clinical outcomes and correct spinal alignment. Sometimes it is necessary to find an acceptable compromise when rebalancing the spine paying attention to the general parameters of the patients like: age, osteoporosis, systemic disease etc., Conclusion: This FBI technique can be used even for small lordosis restoration: it gave a good evaluation of the amount of correction needed and then the surgeon had the choice to use the appropriate technique to obtain a good balance.

We report a case of type 1 complex regional pain syndrome (CRPS I) of the left leg following the implantation of an artificial disc type in the L4/5 segment of the lumbar spine using a midline left-sided retroperitoneal approach. This approach included the mobilisation of the sympathetic trunk with incision and resection of the intervertebral disc. The perioperative and immediate postoperative periods were uneventful, but on the second postoperative day the patient complained of a progressive allodynia of the whole left leg in combination with weakness of the limb. Neurological examination did not reveal any radicular deficit or paresis. A sympathetic reaction following the mobilisation of the sympathetic trunk during the ventral preparation of the spine was suspected and investigated further. A diagnosis of CRPS I was proposed, and the patient was treated with analgesia, co-analgesics for pain alienation, and systemic corticosteroid therapy. A computed tomography-guided sympathetic block and lymphatic drainage were performed. Following conservative orthopaedic rehabilitation therapy, the degree of pain, allodynia, weakness, and swelling were reduced and the condition of the patient was ameliorated. The cost-benefit ratio of spinal arthroplasty is still controversial. The utility of this paper is to debate a possible cause of a painful complication, which can invalidate the results of a successful operation.

Previous papers on resorbable poly-L-lactide-co-D,L-lactide (PLDLLA) cages in spinal fusion have failed to report adequately on patient-centred clinical outcome measures. Also comparison of PLDLLA cage with a traditionally applicable counterpart has not been previously reported. This is the first randomized prospective study that assesses clinical outcome of PLDLLA cage compared with a poly-ether-ether-ketone (PEEK) implant. Twenty-six patients were randomly assigned to undergo instrumented posterior lumbar interbody fusion (PLIF) whereby either a PEEK cage or a PLDLLA cage was implanted. Clinical outcome based on visual analogue scale scores for leg pain and back pain, as well as Oswestry Disability Index (ODI) and SF-36 questionnaires were documented and analysed. When compared with preoperative values, all clinical parameters have significantly improved in the PEEK group at 2 years after surgery with the exception of SF-36 general health, SF-36 mental health and SF-36 role emotional scores. No clinical parameter showed significant improvement at 2 years after surgery compared with preoperative values in the PLDLLA patient group. Only six patients (50%) in the PLDLLA group showed improvement in the VAS scores for leg and back pain as well as the ODI, as opposed to 10 patients (71%) in the PEEK group. One-third of the patients in the PLDLLA group actually reported worsening of their pain scores and ODI. Three cases of mild to moderate osteolysis were seen in the PLDLLA group. Following up on our preliminary report, these 2-year results confirm the superiority of the PEEK implant to the resorbable PLDLLA implant in aiding spinal fusion and alleviating symptoms following PLIF in patients with degenerative spondylolisthesis associated with either canal stenosis or foramen stenosis or both and emanating from a single lumbar segment.

Elastic fibres are critical constituents of dynamic biological structures that functionally require elasticity and resilience. The network of elastic fibres in the anulus fibrosus of the intervertebral disc is extensive, however until recently, the majority of histological, biochemical and biomechanical studies have focussed on the roles of other extracellular matrix constituents such as collagens and proteoglycans. The resulting lack of detailed descriptions of elastic fibre network architecture and mechanical function has limited understanding of the potentially important contribution made by elastic fibres to healthy disc function and their possible roles in the progression of disc degeneration. In addition, it has made it difficult to postulate what the consequences of elastic fibre related disorders would be for intervertebral disc behaviour, and to develop treatments accordingly. In this paper, we review recent and historical studies which have examined both the structure and the function of the human lumbar anulus fibrosus elastic fibre network, provide a synergistic discussion in an attempt to clarify its potentially critical contribution both to normal intervertebral disc behaviour and the processes relating to its degeneration, and recommend critical areas for future research.

The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc prostheses. Both theoretical and experimental studies were analyzed, by a PUBMED search (performed in February 2007, revised in January 2008), focusing on single level TDA. Both semi-constrained and unconstrained lumbar discs seem to be able to restore nearly physiological IAR locations and ROM values. However, both increased and decreased ROM was stated in some papers, unrelated to the clinical outcome. Segmental lordosis alterations after TDA were reported in most cases, for both constrained and unconstrained disc prostheses. An increase in the load through the facet joints was documented, for both semi-constrained and unconstrained artificial discs, but with some contrasting results. Semi-constrained devices may be able to share a greater part of the load, thus protecting the surrounding biological structure from overloading and possible early degeneration, but may be more susceptible to wear. The next level of development will be the biomechanical integration of compression across the motion segment. All these findings need to be supported by long-term clinical outcome studies.

Spine surgeons are becoming increasingly aware of sacral insufficiency fractures as a complication after lumbosacral fusions. We present four patients who suffered from sacral fractures after multi-segmental posterior lumbosacral fusion together with a systematic review of the literature that yielded six papers reporting on 12 cases. Summarizing these 16 cases, the typical patient suffering from this complication is a female, elderly individual [66.4 +/- 12.3 (mean +/- SD) years of age, 95% confidence interval 57.89-71] undergoing multilevel fusion of 4.9 +/- 3.4 (95% CI 3.1-6.8) segments. Due to nonspecific clinical complaints and inconclusive imaging there has been a median delay in diagnosis of 5 (IQR 3-6, range 1-49) weeks after onset of pain. It remains unclear whether this complication is rare or rather under-diagnosed. Fortunately, these fractures are predominantly benign conditions that respond well to conservative management in the majority of cases, depending on location.

This article reports about the internet based, second multicenter study (MCS II) of the spine study group (AG WS) of the German trauma association (DGU). It represents a continuation of the first study conducted between the years 1994 and 1996 (MCS I). For the purpose of one common, centralised data capture methodology, a newly developed internet-based data collection system ( http://www.memdoc.org ) of the Institute for Evaluative Research in Orthopaedic Surgery of the University of Bern was used. The aim of this first publication on the MCS II was to describe in detail the new method of data collection and the structure of the developed data base system, via internet. The goal of the study was the assessment of the current state of treatment for fresh traumatic injuries of the thoracolumbar spine in the German speaking part of Europe. For that reason, we intended to collect large number of cases and representative, valid information about the radiographic, clinical and subjective treatment outcomes. Thanks to the new study design of MCS II, not only the common surgical treatment concepts, but also the new and constantly broadening spectrum of spine surgery, i.e. vertebro-/kyphoplasty, computer assisted surgery and navigation, minimal-invasive, and endoscopic techniques, documented and evaluated. We present a first statistical overview and preliminary analysis of 18 centers from Germany and Austria that participated in MCS II. A real time data capture at source was made possible by the constant availability of the data collection system via internet access. Following the principle of an application service provider, software, questionnaires and validation routines are located on a central server, which is accessed from the periphery (hospitals) by means of standard Internet browsers. By that, costly and time consuming software installation and maintenance of local data repositories are avoided and, more importantly, cumbersome migration of data into one integrated database becomes obsolete. Finally, this set-up also replaces traditional systems wherein paper questionnaires were mailed to the central study office and entered by hand whereby incomplete or incorrect forms always represent a resource consuming problem and source of error. With the new study concept and the expanded inclusion criteria of MCS II 1, 251 case histories with admission and surgical data were collected. This remarkable number of interventions documented during 24 months represents an increase of 183% compared to the previously conducted MCS I. The concept and technical feasibility of the MEMdoc data collection system was proven, as the participants of the MCS II succeeded in collecting data ever published on the largest series of patients with spinal injuries treated within a 2 year period.

The current evidence for total disc replacement was assessed by performing a systematic review of the published literature. This search identified two randomised controlled trials (RCTs), two previous systematic reviews, seven prospective cohort studies, eleven retrospective cohort studies and eight case series. The RCTs involved the use of the Charité artificial disc and the Pro-Disc II total disc replacement. All papers analysed were classified according to their level of evidence as defined by the Centre for Evidence Based Medicine, Oxford, UK (www.cebm). For degenerative disc disease at L4/5 or L5/S1, both the clinical outcome and the incidence of major neurological complications following insertion of the Charité artificial disc were found to be equivalent to those observed following a single level anterior lumbar interbody fusion 2 years following surgery. However, only 57% of patients undergoing total disc replacement and 46% of patients undergoing arthrodesis met the four criteria listed for success. The range of flexion/extension was restored and maintained with the Charité artificial disc. The role for two or three level disc replacement in the treatment of degenerative disc disease remains unproven. To date, no study has shown total disc replacement to be superior to spinal fusion in terms of clinical outcome. The long-term benefits of total disc replacement in preventing adjacent level disc degeneration have yet to be realised. Complications of total disc replacement may not be known for many years. There are numerous types of disc prostheses and designs under study or in development. Well designed prospective RCTs are needed before approval and widespread application of this technology.

Vertebral osteomyelitis due to mucormycosis is a rare but fulminant and fatal disease. Only one case has been reported in literature, with postmortem diagnosis. The present paper reports a female case of mucormycosis spondylodiscitis and vertebral osteomyelitis after lumbar disc puncture and radio frequency nucleoplasty. She subsequently underwent two surgical debridements, continuous local irrigation and drainage, together with local and systemic Amphotericin B treatments. The infection was controlled 4 months after the second debridement; however, there was no improvement in the neurological function at the most recent follow-up, 16 months after the surgery. The experience of this patient, though a single case, supports early recognition, surgical debridement, systemic and local antifungal treatment, closed irrigation and drainage as the keys to successful treatment.

The prevalence of low back pain is high, and the intervertebral (IV) disc is regarded as one of the major causes. Various approaches have been reported to either slow down disc degeneration or to repair/regenerate the disc. So far, the effect of the mechanical environment has not been addressed in these approaches, although several investigations have shown its influence on other mesenchymal tissues. In this paper, we propose that the biophysical stimuli from the mechanical environment can directly influence cell type, as well as their metabolic activity during repair/regeneration of the IV disc. To demonstrate the potential of this idea, data from the literature, as well as explorative experimental results, are presented.

Chordoma is a rare bone tumor that originates from the remnants of the notochord. These tumors have axial distribution particularly at the upper and lower ends of the vertebral column. This paper reports a rare occurrence of a chordoma in the posterior elements of the L5 vertebra. A differential diagnosis of a benign tumor (giant cell tumor, aneurysmal bone cyst or osteoblastoma) was made initially. Other differential diagnoses included plasmacytoma and metastasis. The tumor was removed enbloc. Histopathological examination revealed the tumor mass to be chordoma. There were no clinical or radiological signs of recurrence at 21 months follow-up. Chordomas are tumors of the axial skeleton. However, they may occur in unusual sites in ectopic notochordal tissue. The case is being presented for its unusual site of occurrence.

The literature reports on the safety and efficacy of titanium cages (TCs) with additional posterior fixation for anterior lumbar interbody fusion. However, these papers are limited to prospective cohort studies. The introduction of TCs for spinal fusion has resulted in increased costs, without evidence of superiority over the established practice. There are currently no prospective controlled trials comparing TCs to femoral ring allografts (FRAs) for circumferential fusion in the literature. In this prospective, randomised controlled trial, our objective was to compare the clinical outcome following the use of FRA (current practice) to the use of TC in circumferential lumbar spinal fusion. Full ethical committee approval and institutional research and development departmental approval were obtained. Power calculations estimated a total of 80 patients (40 in each arm) would be required to detect clinically relevant differences in functional outcome. Eighty-three patients were recruited for the study fulfilling strict entry requirements (>6 months chronic discogenic low back pain, failure of conservative treatment, one- or two-level discographically proven discogenic low back pain). The patients completed the Oswestry Disability Index (ODI), Visual Analogue Score (VAS) for back and leg pain and the Short-Form 36 (SF-36) preoperatively and also postoperatively at 6, 12 and 24 months, respectively. The results were available for all the 83 patients with a mean follow-up of 28 months (range 24-75 months). Five patients were excluded on the basis of technical infringements (unable to insert TC in four patients and FRA in one patient due to the narrowing of the disc space). From the remaining 78 patients randomised, 37 received the FRA and 41 received the TC. Posterior stabilisation was achieved with translaminar or pedicle screws. Baseline demographic data (age, sex, smoking history, number of operated levels and preoperative outcome measures) showed no statistical difference between groups (p<0.05) other than for the vitality domain of the SF-36. For patients who received the FRA, mean VAS (back pain) improved by 2.0 points (p<0.01), mean ODI improved by 15 points (p=<0.01) and mean SF-36 scores improved by >11 points in all domains (p<0.03) except that of general health and emotional role. For patients who received the TC, mean VAS improved by 1.1 points (p=0.004), mean ODI improved by 6 points (p=0.01) and SF-36 improved significantly in only two of the eight domains (bodily pain and physical function). Revision procedures and complications were similar in both groups. In conclusion, this prospective, randomised controlled clinical trial shows the use of FRA in circumferential lumbar fusion to be associated with superior clinical outcomes when compared to those observed following the use of TCs. The use of TCs for circumferential lumbar spinal fusion is not justified on the basis of inferior clinical outcome and the tenfold increase in cost.

The recommended surgical options for postoperative wound infections after instrumented spine surgery include a wide debridement and irrigation with antibiotics. In most cases, implant removal is not recommended for a solid fusion. However, there are few reports on the treatment choices for persistent postoperative wound infections following a posterior lumbar interbody fusion (PLIF) using cages. This paper reviewed ten patients referred to our department, who underwent revision surgery for a postoperative, deep infection after a PLIF with cages. The surgery included an anterior radical debridement and interbody fusion with removal of all implants. The clinical and laboratory results, including a bacteriologic study for the causative organism and the radiological changes, were analyzed. All patients complained of persistent severe back pain after the primary surgery. MRSA was the main organism found in these patients (five cases). Complete bony fusion was obtained in nine patients (90%). In one patient, back pain and radiating pain prevented him from returning to his original work. Despite the anterior interbody fusion with an autogenous iliac bone graft, all cases had a complete collapse of the intervertebral disc space, without a dislodgement or collapse of the graft bone. The mean loss of the height and lordosis in the involved segment was 12.7 mm (range 4-46 mm) and 5.6 degrees (range 0-15 degrees ), respectively. Anterior radical debridement with the removal of all implants would be an effective way to manage patients with postoperative spondylitis after a PLIF using cages.

Microdiscectomy represents the gold standard in disc surgery on the lumbar spine. The remaining defect in the intervertebral disc space can be filled with a newly developed nucleus prosthesis presented in this paper. This prosthesis consists of polycarbonate urethane (Sulene PCU), and takes the form of a memory coiling spiral. It can be easily implanted using the standard microdiscectomy approach with no further tissue damage. Biomechanical tests have shown that anatomical distances can be restored by the spiral for both the facet joints and the endplates. Endplate deformations are not statistically different when compared to intact conditions. Inclusion and exclusion criteria of an in vivo pilot study are presented. The paper describes the insertion setup for the spiral and the technique of implantation. Five patients have been supplied with the implant to date. The first results on postoperative magnetic resonance images are presented.

Total disc replacement has become an option for the treatment of degenerative disc disease of the lumbar spine. A new generation of implants has been developed that can be implanted through minimally invasive anterior approaches to the lumbar levels L2/3, L3/4, L4/5 and L5/S1. However mid- and long-term data are still lacking. This paper describes the minimally invasive surgical approach - techniques as well as the preliminary results of our first 34 consecutive patients. The intervertebral spaces L5/S1, L4/5, L3/4 and L2/3 were each approached through slightly different, but standardized, mini-laparotomies either through a retroperitoneal or a transperitoneal route. The clinical results with a follow-up of up to 1 year show satisfactory outcomes in about 80% of the patients. Oswestry score as well as VAS values show significant changes during the postoperative course. There have been three complications (8.8%), two of which were specific to the implantation process, but were resolved with a good clinical outcome in both patients. The preliminary results suggest that total disc replacement may become a reasonable alternative to spinal fusion under the selection criteria used in this study.

This paper details the quantitative three-dimensional anatomy of lumbar vertebrae L1-L5 from Asian (Singaporean) subjects based on 60 lumbar vertebrae from 12 cadavers. The purpose of the study was to measure the dimensions of the various parameters of the lumbar vertebrae and thereafter to compare the data with a study performed on Caucasian specimens. Measurements were taken with the aid of a three-dimensional digitiser. The means and standard errors for linear, angular and area dimensions of the vertebral body, spinal canal, pedicle, and spinous and transverse processes were obtained for each lumbar vertebra. From this comparison, it was found that the dimensions of the vertebral body of the Asian subjects are slightly larger, with a maximum average difference of 8% for the posterior vertebral body height. The dimensions of the spinal canal, pedicle, and spinous and transverse processes of Asian subjects are smaller. The greatest difference can be found in the spinal canal area and pedicle width, which are smaller by an average of 30% and 20%, respectively. With the exception of the spinal canal depth, spinal canal area and pedicle width, all other parameters compared show a similar trend. The findings can provide more accurate modelling for analysis and spinal implant design and also allow more precise clinical diagnosis in sub-Asian groups.

This review provides methodological background and some guidelines for the evaluation of imaging modalities for the lumbar spine and reviews the current literature on the basis of different levels of efficacy which consider standards beyond technical quality or diagnostic accuracy. From a MEDLINE search, 672 articles (1985-1995) were retrieved which focused on the development or application of imaging modalities for lumbar spinal disorders. The papers were categorized according to different efficacy levels at which the imaging modalities were assessed. This review has demonstrated that the vast majority of reports evaluate imaging studies for the lumbar spine only at the technical efficacy level. A minor proportion of the articles focus on the evaluation at the level of diagnostic accuracy. Articles which assess imaging studies on a higher level of efficacy (e.g., diagnostic and therapeutic impact, patient outcome and cost-benefit analysis) are sparse. This review has outlined frequent methodological flaws in patient selection and design of imaging studies for the lumbar spine. The spine specialist should therefore become very critical in the interpretation of those studies and pay attention to patient selection and spectrum, choice of the reference standard, sample size, various forms of biases, and the reasoning behind clinical recommendations in order to improve his patient care.