A decision tree analysis to predict clinical outcome of minimally invasive lumbar decompression surgery for lumbar spinal stenosis with and without coexisting spondylolisthesis and scoliosis.

BACKGROUND CONTEXT: Implementing machine learning techniques, such as decision trees, known as prediction models that use logical construction diagrams, are rarely used to predict clinical outcomes. PURPOSE: To develop a clinical prediction rule to predict clinical outcomes in patients who undergo minimally invasive lumbar decompression surgery for lumbar spinal stenosis with and without coexisting spondylolisthesis and scoliosis using a decision tree model. STUDY DESIGN/SETTING: A retrospective analysis of prospectively collected data. PATIENT SAMPLE: This study included 331 patients who underwent minimally invasive surgery for lumbar spinal stenosis and were followed up for ≥2 years at 1 institution. OUTCOME MEASURES: Self-report measures: The Japanese Orthopedic Association (JOA) scores and low back pain (LBP)/leg pain/leg numbness visual analog scale (VAS) scores. Physiologic measures: Standing sagittal spinopelvic alignment, computed tomography, and magnetic resonance imaging results. METHODS: Low achievement in clinical outcomes were defined as the postoperative JOA score at the 2-year follow-up <25 points. Univariate and multiple logistic regression analysis and chi-square automatic interaction detection (CHAID) were used for analysis. RESULTS: The CHAID model for JOA score <25 points showed spontaneous numbness/pain as the first decision node. For the presence of spontaneous numbness/pain, sagittal vertical axis ≥70 mm was selected as the second decision node. Then lateral wedging, ≥6° and pelvic incidence minus lumbar lordosis (PI-LL) ≥30° followed as the third decision node. For the absence of spontaneous numbness/pain, sex and lateral olisthesis, ≥3mm and American Society of Anesthesiologists physical status classification system score were selected as the second and third decision nodes. The sensitivity, specificity, and the positive predictive value of this CHAID model was 65.1, 69.8, and 64.7% respectively. CONCLUSIONS: The CHAID model incorporating basic information and functional and radiologic factors is useful for predicting surgical outcomes.

Risk Assessment of Anterior Lumbar Interbody Fusion Access in Degenerative Spinal Conditions.

STUDY DESIGN: This was a retrospective cohort study. OBJECTIVE: Develop an evidence-based preoperative risk assessment scoring system for patients undergoing anterior lumbar interbody fusion (ALIF). SUMMARY OF BACKGROUND DATA: ALIF may hold advantages over other fusion techniques in sagittal restoration and fusion rates, though it introduces unique risks to vascular and abdominal structures and thus possibly increased risk of operative morbidity. METHODS: Primary, 1 or 2-level ALIFs were identified in a surgical registry. Baseline characteristics were recorded. Axial magnetic resonance imagings at L4-L5 and L5-S1 were reviewed for vascular confluence/bifurcation or anomalous structures, and measured for operative window size/slope. To assess favorable outcomes, a clinical grade was calculated: (clinical grade=blood loss×operative duration), higher value indicating poorer outcome. To establish a risk scoring system, a base risk score algorithm was established and stratified into 5 categories: high, high to intermediate, intermediate, intermediate to low, and low. Modifiers to base risk score included age, body mass index, operative level, history of bone morphogenic protein use, calcified vasculature, spondylolisthesis grade, working window size and slope, and abnormal vasculature. Modifiers were weighted for contribution to surgical risk. A total risk score was calculated and evaluated for strength of association with clinical outcome grades by Pearson correlation coefficient. RESULTS: A total of 65 patients were included. Mean clinical outcome grade was 5.6, mean total risk score 21.3±21.5. Multilevel procedures (L4-S1) mean total risk score was 57.3±7.8. L4-L5 mean total risk score was 23.6±5.2; L5-S1 mean total risk score 8.3±6.6. Correlation analysis demonstrated a significant and strong relationship (| r |=0.753; P <0.001) between total risk scores and clinical outcome grades. CONCLUSION: Calculated ALIF risk scores significantly correlated with operative duration and blood loss. This scoring system represents a potential framework to facilitate clinical decision-making and risk assessment for potential ALIF candidates with degenerative spinal pathologies.

Assessment of sagittal spinopelvic parameters in a Taiwanese population with spondylolysis by the EOS imaging system: a retrospective radiological analysis.

BACKGROUND: The impact of sagittal spinopelvic alignment on spondylolysis is well established in Caucasian populations. However, prior studies suggest that people from different ethnological backgrounds showed divergence, and a few studies that focused on Asian populations reported conflicting results. The aim of this study is to use the EOS imaging system to evaluate the spinopelvic parameters of spondylolysis patients, and their relationship with spondylolisthesis, disc degeneration, and age in a Taiwanese population. METHODS: Radiographic sagittal spinopelvic parameters for 45 spondylolysis patients and 32 healthy people were evaluated, including pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), thoracic kyphosis (TK), and lumbar lordosis (LL). The spinopelvic parameters were compared between spondylolytic and control groups. These parameters were further compared between spondylolytic subjects with and without spondylolisthesis, with and without high-grade disc degeneration, and young (< 30 years old) and middle-aged. RESULTS: The PI and LL of the spondylolytic group (52.6°±12.0° and 41.3°±15.2°) were significantly higher than those of the healthy control group (47.16°±7.95° and 28.22°±10.65°). Further analysis of the spondylolytic patients revealed that those with high-grade disc degeneration were more prone to spondylolisthesis (92.3 %) compared to those without (50 %; p = 0.001). The middle-aged group had significantly higher rates of spondylolisthesis (80 %) and high-grade disc degeneration (52.4 %) compared with those for the young group (45 and 16.7 %, respectively; p = 0.017 and 0.047, respectively). No statistically significant difference in the sagittal spinopelvic parameters was found when spondylolytic patients were divided according to the occurrence of spondylolisthesis or high-grade disc degeneration. CONCLUSIONS: In a Taiwanese population, PI and LL were significantly larger in spondylolytic patients. Disc degeneration and age were associated with the occurrence of spondylolisthesis. Ethnological differences should thus be taken into account when making clinical decisions regarding spondylolysis in a Taiwanese population.

Clinical appearance and reliability in visual assessment after in situ fusion for high-grade isthmic spondylolisthesis.

PURPOSE: The current literature on clinical appearance after surgery for high-grade spondylolisthesis is inconclusive. The few long-term comparative studies on surgical reduction versus in situ fusion report contradictory findings concerning appearance-related issues. The purpose of the current study was to evaluate and quantify clinical appearance three decades after in situ fusion for high-grade isthmic spondylolisthesis. METHODS: The Scoliosis Research Society (SRS)-22r questionnaire, digital photographs and standing lateral radiographs were used to evaluate clinical appearance for 22 patients three decades after in situ fusion for high-grade spondylolisthesis. The appearance was assessed by two spine surgeons, by the patient themselves, and by quantification of cosmesis relevant radiographic variables including pelvic parameters and sagittal balance. RESULTS: The surgeon inter- and intraobserver reliability of the photographic evaluation of the trunk deformity was at most moderate (Cohen's kappa 0.5). Correlation analysis revealed at most medium correlation between radiographic outcome and self-rated (SRS-22r) self-image (Spearman's rank correlation coefficient 0.3). The agreement between patient and surgeon-rated trunk appearance was poor (Cohen's kappa 0.2). CONCLUSIONS: Photographic evaluation of the trunk deformity in high-grade spondylolisthesis is unreliable. There were only weak correlations between patient self-assessed trunk appearance and radiographic parameters. The results reflect the pronounced subjectivity of cosmesis, and that the trunk deformity in high-grade spondylolisthesis is not easily observed. LEVEL OF EVIDENCE: IV.

Real-time dynamic 3-T MRI assessment of spine kinematics: a feasibility study utilizing three different fast pulse sequences.

BACKGROUND: Half-Fourier acquisition single-shot turbo spin-echo (HASTE), continuous radial gradient-echo (GRE), and True FISP allow real-time dynamic assessment of the spine. PURPOSE: To evaluate the feasibility of adding dynamic sequences to routine spine magnetic resonance imaging (MRI) for assessment of spondylolisthesis. MATERIAL AND METHODS: Retrospective review was performed of patients referred for dynamic MRI of the cervical or lumbar spine between January 2017 and 2018 who had flexion-extension radiographs within two months of MRI. Exclusion criteria were: incomplete imaging; spinal hardware; and inability to tolerate dynamic examination. Blinded, independent review by two board-certified musculoskeletal radiologists was performed to assess for spondylolisthesis (>3 mm translation); consensus review of dynamic radiographs served as the gold standard. Cervical spinal cord effacement was assessed. Inter-reader agreement and radiographic concordance was calculated for each sequence. RESULTS: Twenty-one patients were included (8 men, 13 women; mean age 47.9 ± 16.5 years). Five had MRI of the cervical spine and 16 had MRI of the lumbar spine. Mean acquisition time was 18.4 ± 1.7 min with dynamic sequences in the range of 58-77 s. HASTE and True FISP had the highest inter-reader reproducibility (κ = 0.88). Reproducibility was better for the lumbar spine (κ = 0.94) than the cervical spine (κ = 0.28). Sensitivity of sequences for spondylolisthesis was in the range of 68.8%-78.6%. All three sequences had high accuracy levels: ≥90.5% averaged across the cervical and lumbar spine. Cervical cord effacement was observed during dynamic MRI in two cases (100% agreement). CONCLUSION: Real-time dynamic MRI sequences added to spine MRI protocols provide reliable and accurate assessment of cervical and lumbar spine spondylolisthesis during flexion and extension.

Clinical feasibility of 2D dynamic sagittal HASTE flexion-extension imaging of the cervical spine for the assessment of spondylolisthesis and cervical cord impingement.

PURPOSE: To assess the utility of a 2D dynamic HASTE sequence in assessment of cervical spine flexion-extension, specifically (1) comparing dynamic spondylolisthesis to radiographs and (2) assessing dynamic contact upon or deformity of the cord. METHODS: Patients with a dynamic flexion-extension sagittal 2D HASTE sequence in addition to routine cervical spine sequences were identified. Static and dynamic listhesis was first determined on flexion-extension radiographs reviewed in consensus. Blinded assessment of the dynamic HASTE sequence was independently performed by 2 radiologists for (1) listhesis and translation during flexion-extension and (2) dynamic spinal cord impingement (cord contact or deformity between neutral, flexion and extension). RESULTS: 32 scans in 32 patients (9 males, 23 females) met inclusion criteria acquired on 1.5 T (n = 15) and 3 T (n = 17) scanners. The mean acquisition time was 51.8 s (range 20-95 seconds). Dynamic translation was seen in 14 patients on flexion-extension radiographs compared to 12 (reader 1) and 13 (reader 2) patients on HASTE, with 90.6 % agreement (K = 0.83; p = 0.789). In all cases dynamic listhesis was ≤3 mm translation with one patient showing dynamic listhesis in the range 4-6 mm. Four cases (13 %) demonstrated deformity of the cord between flexion-extension, not present in the neutral position. For cord impingement there was strong inter-reader agreement (K = 0.93) and the paired sample Wilcoxon signed rank test found no significant difference between the impingement scores of the two readers (p = 0.787). CONCLUSIONS: A sagittal dynamic flexion-extension HASTE sequence provides a rapid addition to standard MRI cervical spine protocols, which may useful for assessment of dynamic spondylolisthesis and cord deformity.

A Comparison of the Abdominal and Lumbar Multifidus Muscle Size in Patients With Lumbar Spondylolisthesis and Healthy Patients at Rest and During Contraction Using Ultrasonography.

OBJECTIVE: Using ultrasonography, this study investigated the abdominal and lumbar multifidus muscle size in patients with lumbar spondylolisthesis compared with healthy patients at rest and during contraction. METHODS: This research was a nonexperimental, analytic case-control study. Ultrasound imaging was used to assess the thickness of the abdominal and lumbar multifidus muscles in 25 healthy patients and 25 patients with spondylolisthesis. For the purpose of this study, both men and women, aged 30 to 70 years, were recruited from physiotherapy clinics affiliated with the University of Social Welfare and Rehabilitation Sciences, Tehran, Iran. Measurements were taken at rest and during contraction. RESULTS: There was a significant difference in abdominal and lumbar multifidus muscle size between the healthy and spondylolisthesic groups, both at rest and contraction (P < .05 in all instances). No significant difference was found between the right and left for all measurements (P > .05). CONCLUSION: Patients with spondylolisthesis had smaller stabilizer muscle thickness at rest and during contraction compared with the healthy group.

Comparisons of direct costs, outcomes, and cost-utility of decompression surgery with fusion versus decompression alone for degenerative lumbar spondylolisthesis.

BACKGROUND: Cost-utility analysis of surgery for degenerative lumber spondylolisthesis (DS) is essential for healthcare providers and patients to select appropriate treatment. The purpose of this study was to review the cost-utility of decompression alone versus decompression with fusion for DS. METHODS: A retrospective review of 99 consecutive patients who were treated for Meyerding grade 1 DS at two representative spine centers was performed. Patients with significant spinal instability were treated by decompression with fusion (F group, 40 patients); all others were treated by decompression surgery alone (D group, 59 patients). All patients were followed for three years. Demographic and radiographic data, health-related quality of life (HRQoL), and the direct cost for surgery were analyzed, and the incremental cost-effectiveness ratio (ICER) was determined using cost/quality-adjusted life years (QALY). RESULTS: There were no differences between the groups in baseline demographics (D vs. F: age 68 ± 9 vs. 66 ± 7 years; 37% vs. 40% female) or HRQoL (ODI: D, 41 ± 16 vs. F, 46 ± 13%). The F group had a higher initial-surgery cost ($18,992 ± 2932) but lower reoperation frequency (7%) than the D group ($7660 ± 2182 and 12%, respectively). The three-year total direct cost was higher for F than for D ($19,222 ± 3332 vs. $9668 ± 6,168, p = .01). ICER was higher for F at one year ($136,408 ± 187,911 vs. $237,844 ± 212,049, p < .01), but was comparable for F and D at three years (D, $41,923 ± 44,503 vs. F, $51,313 ± 32,849, p = .17). CONCLUSION: At the three-year follow-up, the two methods had comparable cost-utility. Both methods were cost-effective (defined as an ICER within three times the per-capita gross domestic product).

Utility of Supine Lateral Radiographs for Assessment of Lumbar Segmental Instability in Degenerative Lumbar Spondylolisthesis.

STUDY DESIGN: Retrospective chart review OBJECTIVE.: To determine whether supine lateral radiographs increase the amount of segmental instability visualized in single-level lumbar degenerative spondylolisthesis, when compared to traditional lateral flexion-extension radiographs. We hypothesized that supine radiographs increase the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to flexion-extension. SUMMARY OF BACKGROUND DATA: Accurate evaluation of segmental instability is critical to the management of lumbar spondylolisthesis. Standing flexion-extension lateral radiographs are routinely obtained, as it is believed to precipitate the forward-backward motion of the segment; however, recent studies with magnetic resonance imaging and computed tomography have shown that the relaxed supine position can facilitate the reduction of the anterolisthesed segment. Here, we show that inclusion of supine lateral radiographs increases the amount of segmental instability seen in single-level lumbar spondylolisthesis when compared to traditional lateral radiographs. METHODS: Supine lateral radiographs were added to the routine evaluation (standing neutral/flexion/extension lateral radiographs) of symptomatic degenerative spondylolisthesis at our institution. In this retrospective study, 59 patients were included. The amount of listhesis was measured and compared on each radiograph: standing neutral lateral ("neutral"), standing flexion lateral ("flexion"), standing extension lateral ("extension"), and supine lateral ("supine"). RESULTS: A total of 59 patients (51 women, 8 men), with a mean age of 63.0 years (±9.85 yr) were included. The mean mobility seen with flexion-extension was 5.53 ±â€Š4.11. The mean mobility seen with flexion-supine was 7.83% ±â€Š4.67%. This difference was significant in paired t test (P = 0.00133), and independent of age and body mass index. Maximal mobility was seen between flexion and supine radiographs in 37 patients, between neutral and supine radiographs in 11 cases, and between traditional flexion-extension studies in 11 cases. CONCLUSION: Supine radiograph demonstrates more reduction in anterolisthesis than the extension radiograph. Incorporation of a supine lateral radiograph in place of extension radiograph can improve our understanding of segmental mobility when evaluating degenerative spondylolisthesis. LEVEL OF EVIDENCE: 3.

Temporal Evolution of Disc in Young Patients with Low Back Pain and Stress Reaction in Lumbar Vertebrae.

BACKGROUND AND PURPOSE: Although stress-induced bony changes often resolve with conservative treatment, the long-term effects of such mechanical stresses on intervertebral discs have not been studied. We aimed to assess the differences in the temporal evolution of disc in segments of the lumbar spine with and without signs of increased mechanical stresses. MATERIALS AND METHODS: Using MR imaging performed >6 months apart, 2 radiologists evaluated lumbar intervertebral discs for degenerative changes affecting the annulus fibrosus, the nucleus pulposus, and the endplates in 42 patients (22 male, 20 female; mean age, 16.0 ± 3.7 years [range, 7-25 years]) with low back pain and imaging evidence of stress reaction/fracture in the lumbar spine. Data were analyzed for differences in the presence and progression of disc degeneration in stressed versus nonstressed segments. RESULTS: At baseline, stressed discs had a higher burden of annular fissures, radial fissures, herniation, and nuclear degeneration. Endplate defect burden was comparable in stressed and control discs. At follow-up, the burden of new annular fissures and endplate defects was comparable for stressed and control discs. However, a higher proportion of stressed discs showed worsening nuclear signal intensity grade (14.3% versus 0% control discs; P = .008) and worsening nuclear degeneration grade (11.9% versus 0% control discs; P = .02). An increased risk of progressive nuclear degeneration of stressed discs was observed irrespective of the outcome of bony changes. CONCLUSIONS: Stressed discs exhibit a higher burden of nuclear and annular degeneration at baseline. These discs have a higher risk of progressive nuclear degeneration irrespective of improvement or worsening of stress-related bony changes.

Assessment of Lumbar Spine Instability Using C-Arm Fluoroscopy.

A 47-year-old woman was referred to physical therapy with a diagnosis of lumbar radiculopathy. Weight-bearing flexion/extension radiographs showed no change in a 13-mm (at L5-S1) spondylolisthesis measured with a neutral posture. Physical therapy with a focus on flexion-biased stabilization exercises was initiated. After failing to improve after 6 weeks, her referring physician ordered magnetic resonance imaging, which revealed a 6-mm spondylolisthesis in a supine position. Additionally, the physical therapist performed an anterior stability test of L5 on S1 under C-arm fluoroscopy, which demonstrated a palpable shift of S1 posteriorly that was measured on imaging as a change from a 13-mm to a 17-mm spondylolisthesis. J Orthop Sports Phys Ther 2016;46(9):810. doi:10.2519/jospt.2016.0415.

Surgical management of lumbar degenerative spondylolisthesis.

Lumbar degenerative spondylolisthesis (DS) is a common cause of low back pain, radiculopathy, and/or neurogenic claudication. Treatment begins with a trial of nonsurgical methods, including physical therapy, NSAIDs, and epidural corticosteroid injections. Surgical treatment with decompression and fusion is recommended for patients who do not respond to this initial regimen. Although much has been published in the past two decades on the surgical management of DS, the optimal method remains controversial. Interbody fusion may improve arthrodesis rates and can be performed via numerous surgical approaches. Minimally invasive techniques continue to be developed. Particular attention to surgical management of DS in the elderly is warranted given the increasing numbers of elderly persons. Healthcare utilization in the future must take into account evidence-based medicine that establishes clinically effective practices while simultaneously being cost effective.

Computer tomography assessment of pedicle screw placement in lumbar and sacral spine: comparison between free-hand and O-arm based navigation techniques.

Transpedicular screw fixation has been accepted worldwide since Harrington et al. first placed pedicle screws through the isthmus. In vivo and in vitro studies indicated that pedicle screw insertion accuracy could be significantly improved with image-assisted systems compared with conventional approaches. The O-arm is a new generation intraoperative imaging system designed without compromise to address the needs of a modern OR like no other system currently available. The aim of our study was to check the accuracy of O-arm based and S7-navigated pedicle screw implants in comparison to free-hand technique described by Roy-Camille at the lumbar and sacral spine using CT scans. The material of this study was divided into two groups, free-hand group (group I) (30 patients; 152 screws) and O-arm group (37 patients; 187 screws). The patients were operated upon from January to September 2009. Screw implantation was performed during PLIF or TLIF mainly for spondylolisthesis, osteochondritis and post-laminectomy syndrome. The accuracy rate in our work was 94.1% in the free-hand group compared to 99% in the O-arm navigated group. Thus it was concluded that free-hand technique will only be safe and accurate when it is in the hands of an experienced surgeon and the accuracy of screw placement with O-arm can reach 100%.

A radiographic assessment of the ability of the extreme lateral interbody fusion procedure to indirectly decompress the neural elements.

STUDY DESIGN: Prospective nonrandomized clinical study on the decompressive effect of the extreme lateral interbody fusion (XLIF) procedure. OBJECTIVE: This study evaluates the results of interbody distraction from a lateral retroperitoneal approach for the treatment of lumbar degenerative conditions inclusive of central and/or lateral stenosis. SUMMARY OF BACKGROUND DATA: Traditional treatment for symptomatic lumbar stenosis has been by direct posterior decompression (i.e., removal of ligamentum flavum, laminotomy/laminectomy, facetectomy, as needed). Stenotic symptoms may also be alleviated indirectly, through correction of intervertebral and foraminal height and correction of spinal alignment. Anterior-only spinal procedures rely on this indirect decompression when used in patients with radicular symptoms. METHODS: Consecutive patients presenting with degenerative conditions that included concomitant lumbar stenosis were consented and treated via stand-alone XLIF. Pre- and postoperative radiographic measurements were made from plain lateral radiographs and sagittal and axial magnetic resonance imaging views by an independent radiologist using medical imaging software. Measurements included disc height, foraminal height, foraminal area, and canal diameter. RESULTS: In all, 7 male and 14 female patients (mean age, 67.6 years; range, 40-83) underwent XLIF at 43 lumbar levels in an average operative time of 47 minutes and with an average 23 mL estimated blood loss per level. There were no intraoperative complications. Mean hospital stay was 29.5 hours. Transient postoperative psoas weakness occurred in 3 (14.3%) of the cases. Substantial dimensional improvement was evidenced in all radiographic parameters, with increases of 41.9% in average disc height, 13.5% in foraminal height, 24.7% in foraminal area, and 33.1% in central canal diameter. Two patients (9.5%) required a second procedure for additional posterior decompression and/or instrumentation. CONCLUSION: The XLIF procedure provides the necessary decompression for the treatment of central and/orlateral stenosis in a minimally disruptive way, avoiding, in most cases, the need for the direct resection of posterior elements and associated morbidities. Indirect decompression may be limited in cases of congenital stenosis and/or locked facets. Its effect may also be reduced by postoperative subsidence and/or loss of correction.

Clinical application of a novel assessment for lumbosacral stability.

OBJECT: To evaluate the grade of lumbosacral stability, shape analysis was conducted on plain radiographs of the lumbar spine. METHODS: One hundred twenty-six patients were classified into 2 groups: those with a single-segment disc space narrowing at L5-S1 or at L4-5. Stability was evaluated using the discriminant function (z score) derived from the analysis of radiographic parameters-that is, relative thickness of transverse process of L-5 and the sacral table angle. RESULTS: In patients with a space narrowing at L5-S1, the author observed a significantly slender L-5 transverse process and acute obliquity of the sacral endplate; accordingly, the z score was negative. In patients with a broad transverse process and a positive z score, the segment associated with disc height loss was L4-5. Thus, a close correlation was found between the site of the disc height loss and the bony characteristics of L-5 and S-1. Furthermore, it could be expected with a high degree reliability that when young adult patients had a z score less than -2 or -3, their L-5 vertebra would develop degenerative spondylolisthesis after middle age and the L5-S1 segment could be saved from age-related alterations as long as the z score was greater than 2.5. The constitutional characteristics of the lumbosacral junction may exert a major influence on the site of disc degeneration. CONCLUSIONS: Stability at the lumbosacral junction was thought to be quantitatively represented by the z score, with z being designated the lumbosacral stability score.

[Characteristics of clinical findings and radiological assessment of high grade developmental spondylolisthesis].

OBJECTIVES: To investigate clinical appearance and radiological characteristics of high grade developmental spondylolisthesis and their significance. METHODS: In a retrospective study, a group of 6 female patients, who were diagnosed as high grade developmental spondylolisthesis and treated in Peking University third hospital from March 2007 to December 2008 were included. Clinical and radiological characteristics of the 6 patients were investigated and the following parameters were measured on standing lateral X-ray: PI (pelvic incidence), SK (sacral kyphosis) and LL (Lumbar lordosis). A series of 44 patients who came to out-patient department due to LBP and had no positive findings on lateral lumbar X-ray were selected as the control group. The four parameters were compared between study group and control group. Clinical meanings of significant difference were discussed. RESULTS: Clinical findings of high grade developmental spondylolisthesis included bending of knees, deformity of trunk and sciatica. Radiological appearances were characterized with kyphosis of lumbo-sacral joint, retroverted pelvis and domed sacrum. Spondylolisthesis patients has an average PI of (52 +/- 7) degrees which was significant higher than the control group [(43 +/- 8) degrees ] (P < 0.01). LL of study group [(51 +/- 10) degrees ] was higher than that of the control group [(18 +/- 9) degrees ] (P < 0.01) and SK of the study group [(12 +/- 11) degrees ] were lower than that of the control group [(21 +/- 10) degrees ] (P < 0.05). CONCLUSIONS: Characteristics of clinical findings of spondylolisthesis patients have obvious cosmetic appearance, significant pain and lower neurological deficits. Radiological characteristics display deformity of lumbo-sacral joint. PI, LL and SK are significant parameters for high grade spondylolisthesis.

Clinical and radiographic assessment of transforaminal lumbar interbody fusion using HEALOS collagen-hydroxyapatite sponge with autologous bone marrow aspirate.

BACKGROUND CONTEXT: Studies have suggested that the use of bone marrow aspirate (BMA) with HEALOS (DePuy Spine, Raynham, MA), a collagen-hydroxyapatite sponge (CHS), is an effective substitute for autologous iliac crest bone graft when used in fusion procedures of the lumbar spine. PURPOSE: To assess clinical and radiographic outcomes after implantation of BMA/CHS in patients undergoing transforaminal lumbar interbody fusion (TLIF) with posterolateral fusion (PLF). STUDY DESIGN/SETTING: Case series radiographic outcome study. PATIENT SAMPLE: Twenty patients. OUTCOME MEASURES: Radiographs/computed tomography (CT) scans. METHODS: From September 2003 to October 2004, 20 patients (22 interbody levels) were implanted with BMA/CHS via TLIF/PLF with interbody cages and posterior pedicle screws. All patients were retrospectively identified and invited for a 2-year prospective follow-up. Plain radiographs with dynamic films and CT scans were taken, and fusion was assessed in a blinded manner. RESULTS: Follow-up averaged 27 months (range: 24-29). Primary diagnosis included spondylolisthesis (17 patients), scoliosis with asymmetric collapse (2 patients), and postdiscectomy foraminal stenosis (1 patient). The overall fusion rate was 95% (21/22 levels, 19/20 patients). Anteriorly bridging bone was observed in 91% of the anteriorly fused levels (20/22), of which 65% (13/20) occurred through and around the cage and 35% (7/20) around the cage only. Unilateral or bilateral bridging of the posterior fusion masses was observed in 91% (20/22), with 55% occurring bilaterally (12/22). In 4 (18%) cases, bridging only occurred either posteriorly (2 cases) or anteriorly (2 cases). Complications included one deep wound infection. CONCLUSIONS: At the 2-year follow-up, BMA/CHS showed acceptable fusion rates in patients undergoing TLIF/PLF, and can be considered as an alternative source of graft material.

Assessment of lumbosacral kyphosis in spondylolisthesis: a computer-assisted reliability study of six measurement techniques.

Although recognized as an important aspect in the management of spondylolisthesis, there is no consensus on the most reliable and optimal measure of lumbosacral kyphosis (LSK). Using a custom computer software, four raters evaluated 60 standing lateral radiographs of the lumbosacral spine during two sessions at a 1-week interval. The sample size consisted of 20 normal, 20 low and 20 high grade spondylolisthetic subjects. Six parameters were included for analysis: Boxall's slip angle, Dubousset's lumbosacral angle (LSA), the Spinal Deformity Study Group's (SDSG) LSA, dysplastic SDSG LSA, sagittal rotation (SR), kyphotic Cobb angle (k-Cobb). Intra- and inter-rater reliability for all parameters was assessed using intra-class correlation coefficients (ICC). Correlations between parameters and slip percentage were evaluated with Pearson coefficients. The intra-rater ICC's for all the parameters ranged between 0.81 and 0.97 and the inter-rater ICC's were between 0.74 and 0.98. All parameters except sagittal rotation showed a medium to large correlation with slip percentage. Dubousset's LSA and the k-Cobb showed the largest correlations (r= -0.78 and r= -0.50, respectively). SR was associated with the weakest correlation (r= -0.10). All other parameters had medium correlations with percent slip (r= 0.31-0.43). All measurement techniques provided excellent inter- and intra-rater reliability. Dubousset's LSA showed the strongest correlation with slip grade. This parameter can be used in the clinical setting with PACS software capabilities to assess LSK. A computer-assisted technique is recommended in order to increase the reliability of the measurement of LSK in spondylolisthesis.

Major vascular injury during anterior lumbar spinal surgery: incidence, risk factors, and management.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To examine the incidence of major vascular injury during anterior lumbar spinal surgery, attempt to identify predisposing risk factors, and to discuss management techniques. SUMMARY OF BACKGROUND DATA: Major vascular injury can be a catastrophic complication of anterior lumbar spinal surgery. METHODS: Current procedural terminology codes were used to identify the occurrence of major vascular injury, defined as injury to the iliac vessels, vena cava, and aorta. Once identified, the office record, hospital chart, operative note, and diagnostic test results were reviewed in detail. RESULTS: Three hundred forty-five operations were performed on 338 patients. Incidence of major vascular complication was 2.9% (10 of 345). There were 9 injuries of the common iliac vein and a single aortic injury. Risk factors identified in patients with major vascular injury were current or previous osteomyelitis or discogenic infection (n = 3), previous anterior spinal surgery (n = 2), spondylolisthesis (n = 2; 1 isthmic Grade II, 1 iatrogenic Grade II), large anterior osteophyte (n = 2), transitional lumbosacral vertebra (n = 1), and anterior migration of interbody device (n = 1). Lateral venorrhaphy by suture (n = 6) and hemoclip application (n = 2) was augmented by topical agents, which constituted the sole method of repair on 1 occasion. Magnetic resonance venography demonstrated iliac vein thrombosis in 1 patient. CONCLUSION: Current or previous osteomyelitis or discogenic infection, previous anterior spinal surgery, spondylolisthesis, osteophyte formation, transitional lumbosacral vertebra and anterior migration of interbody device point to an increased risk of vascular injury during anterior lumbar spinal surgery. Careful handling of the vascular structures and liberal use of topical hemostatic agents can lead to control of hemorrhage and preservation of vascular patency. Routine postoperative surveillance for proximal deep vein thrombosis, by magnetic resonance venography of the pelvic veins and inferior vena cava, should be performed after venorrhaphy.

Assessment of sacral doming in lumbosacral spondylolisthesis.

STUDY DESIGN: Quantitative versus subjective evaluation of sacral doming in lumbosacral spondylolisthesis. OBJECTIVES: To evaluate the relevance of the Spinal Deformity Study Group (SDSG) index in the assessment of sacral doming and to propose a quantitative criterion to differentiate between significant and nonsignificant doming. SUMMARY OF BACKGROUND DATA: There is no consensus on the optimal technique to assess sacral doming, although it is an important feature in spondylolisthesis. METHODS: Five spinal surgeons subjectively assessed the sacral endplate of 100 subjects (34 high-grade spondylolisthesis, 50 low-grade spondylolisthesis, 16 controls) from lateral radiographs. Subjects were classified by each surgeon as having significant or nonsignificant sacral doming. An independent observer quantitatively evaluated sacral doming for all subjects using the SDSG index. A criterion to differentiate significant from nonsignificant sacral doming was sought, based on the comparison between the subjective assessment of surgeons and the quantitative evaluation by the independent observer. Intrarater and interrater reliability of the SDSG index was evaluated using intraclass correlation coefficient (ICC). RESULTS: Intrarater and interrater ICCs for the SDSG index were excellent at 0.91 and 0.88, respectively. Sacral doming evaluated with the SDSG index was 11.6% +/- 5.0% (range, 1.5%-18.9%), 16.4% +/- 6.3% (range, 3.7%-35.6%), and 27.9% +/- 10.9% (range, 5.7%-56.9%) for controls, low-grade, and high-grade cases, respectively. Overall intersurgeon agreement on the significance of sacral doming was substantial at 88% (kappa = 0.72). With a threshold value of 25% for the SDSG index, 93% of concordance was found between the quantitative evaluation using the SDSG index and the multisurgeons subjective assessment. CONCLUSION: This study confirms the relevance of the SDSG index to assess sacral doming in lumbosacral spondylolisthesis. The authors propose a criterion of 25% to differentiate significant from nonsignificant sacral doming using the SDSG index. Such a criterion will allow more accurate assessment of sacral remodeling, especially for borderline cases, and facilitate comparisons between studies.