Extension Lateral Radiographs Research Articles

P39. Combining flexion lateral radiographs with a supine MRI is superior to a combination of flexion and extension lateral radiographs at detecting vertebral instability in patients with spondylolisthesis

P39. Combining flexion lateral radiographs with a supine MRI is superior to a combination of flexion and extension lateral radiographs at detecting vertebral instability in patients with spondylolisthesis

Association of findings on preoperative extension lateral cervical radiography with osteotomy type, approach, and postoperative cervical alignment after cervical deformity surgery.

The authors' objective was to determine whether preoperative lateral extension cervical spine radiography can be used to predict osteotomy type and postoperative alignment parameters after cervical spine deformity surgery. A total of 106 patients with cervical spine deformity were reviewed. Radiographic parameters on preoperative cervical neutral and extension lateral radiography were compared with 3-month postoperative radiographic alignment parameters. The parameters included T1 slope, C2 slope, C2-7 cervical lordosis, cervical sagittal vertical axis, and T1 slope minus cervical lordosis. Associations of radiographic parameters with osteotomy type and surgical approach were also assessed. On extension lateral radiography, patients who underwent lower grade osteotomy had significantly lower T1 slope, T1 slope minus cervical lordosis, cervical sagittal vertical axis, and C2 slope. Patients who achieved more normal parameters on extension lateral radiography were more likely to undergo surgery via an anterior approach. Although baseline parameters were significantly different between neutral lateral and extension lateral radiographs, 3-month postoperative lateral and preoperative extension lateral radiographs were statistically similar for T1 slope minus cervical lordosis and C2 slope. Radiographic parameters on preoperative extension lateral radiography were significantly associated with surgical approach and osteotomy grade and were similar to those on 3-month postoperative lateral radiography. These results demonstrated that extension lateral radiography is useful for preoperative planning and predicting postoperative alignment.

P13. ACDF fusion rates

BACKGROUND CONTEXT Anterior cervical discectomy and fusion (ACDF) is a common procedure for the treatment of cervical radiculopathy and myelopathy. PURPOSE Multilevel ACDFs are often used to address multi-level cervical stenosis. The purpose of this study is to provide a chronological, level-specific characterization of fusion order and fusion rates. Such information will be useful when advising patients preoperatively and adequately assessing their post-operative arthrodesis. STUDY DESIGN/SETTING Three-level ACDF cases from March 2016 to October 2019 were reviewed. In total, 57 cases were selected with the following fusion locations: one fusion at C2-5, eight at C3-6, 43 at C4-7, and three at C5-T1. Radiographic measurements were taken at 6 weeks, 6 months, and 1 year postoperatively. Due to incomplete follow-up, we report outcomes for 50, 39, and 23 patients at 6-weeks, 6- months, and 1-year postoperative time points, respectively. PATIENT SAMPLE The studied cohort consisted of 26 males and 29 females with an average age of 59.1 (±9.6) years. OUTCOME MEASURES The primary outcomes measured were fusion rates. Radiographic measurements were performed at 6 weeks, 6 months, and 1 year postoperatively. Fusion criteria are further described in the “methods” section. METHODS Flexion and extension lateral radiographs were obtained for enrolled patients. The junior author independently measured distances between spinous processes at all levels with anterior plating in addition to the immediate noninstrumented cranial level and the immediate non-instrumented caudal level. All measurements were performed with at least 1.5x magnification. Fusion criteria for all levels consisted of £1mm of movement on flexion and extension with an absence of a radiolucent gap between graft and endplate. Additionally, there has to be at least 4mm movement at the non-fusion levels to ensure adequate patient effort with neck flexion/extension. RESULTS At 6 weeks postoperatively, the following fusion rates were observed: 5/50 (17.9%) were fused at the top level; 14/50 (28%) were fused at the middle level, and 3/50 (6%) were fused at the bottom level. At 6 months postoperatively, the following fusion rates were observed: 19/39 (48.7%) patients were fused at the top level, 19/39 (48.7%) were fused at the middle level, and 2/39 (5.1%) were fused at the bottom level. Lastly, at 1 year postoperatively, we observed the following fusion rates: 18/23 (78.3%) were fused at the top level, 23/23 (100%) were fused at the middle level, and 5/23 (21.7%) were fused at the bottom level. Complete bony fusion at all three levels was observed in 5/23 (21.7%) patients at 1 year postoperatively. CONCLUSIONS The preliminary data suggest that the bottom level has highest risk for pseudarthrosis after 3-level ACDF, and the middle level has the highest fusion rate (100%) at 1 year postoperatively. Dr. Lee A. Tan is the co-senior author on this abstract. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Clinical Implication of Mid-Range Dynamic Instability in Lumbar Degenerative Spondylolisthesis.

Study DesignRetrospective evaluation.PurposeTo determine the prevalence of mid-range dynamic instability in patients with degenerative spondylolisthesis (DS) and to evaluate the clinical implication of mid-range instability (MI).Overview of LiteratureInstability is identified by measuring vertebral body anterior–posterior translation on static end-range flexion and extension lateral radiographs. Mid-range kinematics could evince occult dynamic instability in which motion is not appreciated at the terminal-range of motion.MethodsIn this study, 30 patients with DS with checked standing dynamic radiographs of the lumbar spine in Gwangmyeong Sungae Orthopedic Clinic were recruited. Standing lateral radiographs were evaluated in extension, 45° of flexion (mid-range) and 90° of flexion (terminal-range) of the lumbar spine. Instability was defined as sagittal translation greater than 3 mm from the extension position. Patients were divided into three groups: a control group, an MI group, and a terminal-range instability (TI) group. Radiographic outcome (stenosis grade) and clinical outcome were compared between the three groups.ResultsThe average sagittal translation of the lumbar spine was 5.2 mm in extension, 6.6 mm in mid-range, and 7.2 mm in endrange. MI was observed in eight patients (26.2%) and TI was seen in 12 patients (40%). Of eight patients with MI, three patients did not have instability at terminal-range (occult patients) and five patients had instability at terminal-range (typical patients). Body weight and body mass index (BMI) was significantly higher in the MI group as compared to the control group. BMI was positively correlated with slippage to mid-range. There was no significant difference in stenosis grade, Visual Analog Scale, and Oswestry Disability Index. In the TI group, there was no significant difference in radiographic clinical parameters as compared to the control group.Conclusions MI was demonstrated in 25% of DS patients. Mid-range motion was increased with BMI. Mid-range lateral radiography can reveal occult instability in patients with DS, particularly in obese patients.

297. Preoperative extension lateral cervical radiographs are associated with osteotomy type, approach and postoperative cervical alignment following cervical deformity surgery

BACKGROUND CONTEXT Choosing the surgical approach and osteotomy type is challenging when surgically treating cervical deformity. Preoperative assessment of flexibility and final alignment would be useful for surgeons treating this complex problem. Currently extension lateral XR are inconstantly taken for the management of cervical deformity for planning purposes. PURPOSE Investigate the relationship of surgical procedure choice and the pre-operative flexibility of the cervical spine. Determine if extension lateral XR (ELXR) can also predict the final postoperative alignment. STUDY DESIGN/SETTING Retrospective review of prospective, consecutively enrolled multicenter cervical deformity database PATIENT SAMPLE A total of 106 cervical deformity patients OUTCOME MEASURES Surgical treatment, radiographic alignment parameters (SS, T1S-CL, cSVA, C2 slope, T1 slope) METHODS A prospective database of operative cervical deformity patients was analyzed. Inclusion was cervical kyphosis>10°, cervical scoliosis>10°, C2-C7 SVA>4cm or chin-brow vertical angle>25°. Patients were excluded if they did not have neutral and ELXR or did not have deformity limited to the cervical or cervicothoracic spine. The ELXR was compared to preoperative neutral lateral, and 3 mo alignment XR and type of surgical osteotomy based upon the Ames Classification. Statistical analysis included t-test and chi-squared. RESULTS A total of 106 from 164 patients met the inclusion criteria. Mean age of 60 yo, with 58% females. Of the study population, 43.4% of patients had prior cervical surgery. The evaluation of ELXR in patients who received grade 1-2 osteotomies (as compared to those who received grade 5,6 or 7), shows they have statistically lower T1S (23.06 vs 35.46; p=.021), lower T1S-CL (20.90 vs 36.29; p=.033), lower cSVA (24.66 vs 48.35; p 17 in the ELXR (46.77% vs 36.36%; p=.033). Overall, while surgery created a significant change in all radiographic parameters; the 3 month lateral XR and baseline ELXR were statistically similar for T1S-CL (26.04 vs 24.83; p=.542) and C2Slope (23.27 vs 22.87; p=.839). CONCLUSIONS Preoperative ELXR had a significant association with surgical approach and grade of osteotomy. The ELXR was statistically similar to the post-operative 3-month lateral XR and should be used to predict final cervical alignment. Obtaining ELXR is a critical alignment tool, and should be obtained as a part of the preoperative surgical plan. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Sagittal spinopelvic malalignment in degenerative scoliosis patients: isolated correction of symptomatic levels and clinical decision-making

BackgroundThis study aims to determine if (1) loss of lumbar lordosis (LL), often associated with degenerative scoliosis (DS), is structural or rather largely due to positional factors secondary to spinal stenosis; (2) only addressing the symptomatic levels with a decompression and posterolateral fusion in carefully selected patients will result in improvement of sagittal malalignment; and (3) degree of sagittal plane correction achieved with such a local fusion could be predicted by routine pre-operative imaging.MethodsA retrospective study design with prospectively collected imaging data of a consecutive series of surgically treated DS patients who underwent decompression and instrumented fusion at only symptomatic levels was performed. Pre- and post-operative plain radiographs and pre-operative magnetic resonance imaging (MRIs) of the spinopelvic region were analyzed. LL, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were assessed in all patients. As a requirement for the surgical strategy, all patients presented with a pre-operative PI-LL mismatch greater than 10°. Post-operative complications were assessed.ResultsPre-operative MRIs and lumbar extension radiographs revealed a mean LL of 42° (range 10–66°) and 48° (range 20–74°), respectively, in 68 patients (mean follow-up 29 months). LL post-operatively was corrected to a mean PI-LL of 10°. Of patients who achieved PI-LL mismatch within 10o on their pre-operative extension lateral lumbar radiographs, 62.5% were able to maintain a PI-LL mismatch within 10° on their initial post-operative films. Only 37.5% were not able to achieve that mismatch on extension radiographs (p = 0.001, OR = 9.58). Similarly, 54.2% were able to achieve a PI-LL < 10° on initial post-operative radiographs, when pre-operative MRI revealed a PI-LL mismatch within 10°. In contrast, only 20.5% achieved that goal post-operatively if their mismatch was greater than 10o on their MRI (p = 0.003, OR = 4.25).ConclusionWith a decompression and instrumented fusion of only the symptomatic levels in symptomatic DS patients, we were able to achieve a PI-LL mismatch to within 10°. The loss of LL observed pre-operatively may be largely positional rather than structural. The amount of LL correction observed immediately after surgery can be predicted from pre-operative lumbar extension radiographs and supine sagittal MRI.

Is Delayed Surgery After Unsuccessful Conservative Treatment Beneficial for Spinal Cord Injury Following Whiplash? A Retrospective Study in Elderly Patients.

BackgroundThe aim of this study was to investigate the clinical outcomes of early and delayed surgery in cervical spinal cord injury following whiplash in elderly patients.Material/MethodsOur retrospective review identified elderly patients (≥65 years old) with spinal cord injury following whiplash injury from 2006 to 2015. The neck disability index (NDI), modify Japanese Orthopedics Association (mJOA) score, and visual analogue scale (VAS) score were used to evaluate clinical outcomes preoperatively and during follow-up. The angular range of motion (ROM) for C2–C7 was measured by dynamic flexion and extension lateral cervical radiographs at each observation follow-up time point. Treatment-related complication data were collected, and the complication rates analyzed.ResultsForty-six elderly patients (age range 65–82 years) with spinal cord injury following whiplash injury were enrolled in this study. Twenty-four patients underwent early surgery and twenty-two patients (age range 65–78 years) received delayed surgery after conservative treatment failure. During the follow-up period, both groups had significant post-operative improvement in NDI, mJOA, and VAS scores (p<0.05), although the early surgery group had better outcomes than the delayed surgery after unsuccessful conservative treatment group (p<0.05). However, on average, no significant differences in sagittal C2–C7 ROM between the two groups were found during follow-up. Comparison of the two groups showed the incidences of pneumonia and deep vein thrombosis were significantly higher in the delayed surgery group (p<0.05).ConclusionsThis study indicated that delayed surgery after unsuccessful conservative treatment provided excellent clinical results for elderly patients; however, timely surgical intervention is necessary for neurological symptom deterioration.

Variations in sagittal locations of anterior cruciate ligament tibial footprints and their association with radiographic landmarks: a human cadaveric study

BackgroundThis cadaveric study aimed to demonstrate variation of the anterior cruciate ligament (ACL) tibial attachment in the sagittal plane, and to analyze the radiographic landmarks which predict the sagittal location of the ACL tibial attachment.MethodsIn 20 cadaveric knees, native ACLs were removed and the centers of the ACL tibial and femoral attachments were marked with metal pins. Full extension lateral radiographs were then obtained in each cadaveric knee. Using the full extension lateral radiographs, the sagittal location of the ACL tibial footprint center was estimated as a percentage in the Amis and Jakob’s line. Several radiographic landmarks including the geometry of Blumensaat’s line and the apex of the tibial eminence were measured. Then, the relationship between the variation of the sagittal location of the ACL tibial footprint and several radiographic landmarks were analyzed using Pearson’s correlation analysis.ResultsThe average sagittal position of the native ACL tibial footprint was 40.9% (range: 38.0–45.0%). The line connecting the centers of the ACL footprint was nearly parallel to Blumensaat’s line, with an average angle of 1.7° (range: 0–4.1°). In addition, the distance from the point where Blumensaat’s line meets the tibial articular surface to the center of the ACL tibial footprint was almost consistent, at 7.6 mm on average (range: 6.4–8.7 mm). The correlation analysis revealed that the geometry of Blumensaat’s line was significantly correlated with the sagittal location of the ACL tibial footprint.ConclusionThe radiographic landmark that showed a significant correlation with the ACL tibial footprint in the full extension lateral radiographs was Blumensaat’s line.

Machined cervical interfacet allograft spacers for the management of atlantoaxial instability.

Background:The use of cervical interfacet spacers (CISs) to augment stability and provide solid arthrodesis at the atlantoaxial joint has not been studied in detail. The aim of this work is to report the outcomes with the use of machined allograft CISs at C1-2.Methods:A retrospective review of 19 patients who underwent an atlantoaxial fusion with the use of CISs was performed. All patients had instability documented with flexion and extension lateral radiographs. This instability was due to trauma, degenerative stenosis, symptomatic C1-2 arthropathy, and os odontoideum. Clinical and radiological outcomes were assessed. Fusion was determined based on a lack of hardware failure, absence of motion on flexion and extension plain X-ray films, and presence of bridging trabecular bone which was most often demonstrated by a computed tomography.Results:The mean age was 69.1 ± 12.9 years. Eight patients had traumatic fractures, six patients had degenerative stenosis, two patients had C2 neuralgia due to C1-2 arthropathy, two patients had C1-2 ligamentous subluxation, and one patient had an unstable os odontoideum. The occiput or subaxial spine was included in the arthrodesis in 10 patients. Rib autograft was utilized in most patients. No patient had postoperative neurological worsening, malposition of hardware, or vertebral artery injury and there were no mortalities. The fusion rate was 95%. The mean follow-up was 12.1 ± 5.5 months.Conclusions:CIS is a promising adjuvant for the treatment of atlantoaxial instability.

Revision Surgeries following Artificial Disc Replacement of Cervical Spine: Analysis of 21 Cases

Introduction The use of artificial disc replacement of cervical spine (C-ADR) has been advocated to preserve segmental motion and to prevent adjacent segment disease as an alternative to anterior cervical discectomy fusion (ACDF). Previous studies reported satisfactory clinical and radiological outcomes of C-ADR compared with ACDF. However, some patients with C-ADR undergo revision surgeries due to failure of C-ADR, such as persistence or recurrence of symptoms and complications. Therefore, we performed the current study to investigate causes and results of revision surgeries following C-ADR. Material and Methods Twenty-one patients (13 males and 8 females) were treated with revision surgeries for failure of C-ADR and had a minimum 2-year follow-up. Causes for revision surgeries were at least one of the following: 17 poor patient selections (severe spondylosis), 7 insufficient decompressions, 7 malpositions, 6 subsidences, 3 osteolysis, and 1 infection. The mean age was 52.8 years (range, 43–63 years) and mean time to revision surgery was 21 months (range, 4–84 months). During their initial surgeries, 14 patients underwent single-level C-ADR, 2 two-level C-ADR, and 5 two-level hybrid surgery for 16 radiculopathy, 3 myelopathy, and 2 adjacent segment disease. Clinical evaluation was done by neck and arm visual analog scales (VAS) and Neck Disability Index (NDI) score. Fusion status was evaluated by plain radiographs including flexion and extension lateral radiographs. Follow-up measurements were taken before surgery and postoperatively at 1, 3, 6, and 12 months, 24 months as well as at last follow-up. At the 24-month fololow-up, patients' overall satiafaction and final fusion status were evaluated by Odom's criteria and CT scan, respectively. Results Sixteen patients underwent anterior removal of C-ADR (8 MobiC, 4 Discovery, 2 Bryan, 1 Prodisc-C, and 1 Prestige LP), one-level discectomy and fusion with plate ( N = 11), two-level discectomy and fusion with plate ( N = 3) or corpectomy and two-level fusion with plate ( N = 2). Three patients with keel types of C-ADR (2 Prodisc-C and 1 Prestige LP) and extensive heterotopic ossification were treated by laminoforaminotomy with posterior fusion. Two patients (2 Discovery) with kyphosis and severe bone loss due to infection or severe subsidence were treated by combined anterior and posterior approaches. NDI score and neck and arm VAS were improved after revision surgeries at each time point of follow-up. At the 24 months of follow-up, 86% ( N = 18) of the patients was satisfied and 91% ( N = 19) achieved solid fusion. However, 2 patients with pseudoarthrosis did not have sufficient pain to warrant the operative repair of the psuedoarthrosis. No major neurologic and wound complications were developed except transient dysphagia in 6 patients with mean recovery time of 1.7 months (range, 1–4 months). Conclusion Revision surgeries can provide successful outcomes in failure of C-ADR without major neurologic and wound complications. Our results suggest that careful patient selection and meticulous surgical techniques, such as adequate decompression, proper positioning of C-ADR, and preservation of subchondral bone, are important to avoid revision surgeries for failure of C-ADR.

The Role of Minimal Invasive Split Laminotomy, the Alternative Parasplit Approach and the “Arch bone” Technique in Surgical Removal of Axial Longitudinal Pathologies in the Spinal Canal

Introduction Conventional approaches to open the spinal canal carries the risk of spinal deformities, instability, subluxation, and invariably separate the muscle attachments from the spinous processes and laminae. Damage to these muscles and bony connections can lead to persistent axial pain and cervical malalignment. With the aim of preserving and reconstructing the posterior structures, the authors developed a novel minimal invasive multilevel spinous process splitting and distraction laminotomy approach, the “arch bone” and the additional rescue parasplit technique. Patients and Methods These novel techniques were used in 70 adult patients with mainly midline located intramedullary pathologies of the cervical, thoracic, and thoracolumbar spine. All muscle attachments on the spinous processes and laminas, as well as the laminas themselves, were completely preserved. With the aim of moderate enlargement of the spinal canal, a spacer was placed between the bony parts facing each other in case of total resection of an intramedullary tumor was not possible. When midline splitting is not feasible or convenient because of anatomical differences of the spinous processes and laminas, we used the parasplit approach. The patients were followed with regular MRI, CT scans, fluoroscopy, and neurological examinations. Results The midline opening of the spinal canal gave a key-hole approach, achieving an adequate view of the intraspinal space for surgery in its entire longitudinal extension. The approach used did not affect the extent of resection proved by MRI evaluation or neurological outcome. The numbers of splitted laminae were 3 to 10. The incidence of postoperative local pain was lower, within acceptable limits (VAS: 2–4). The average length of hospital stay was 6.7 days. Average follow-up was 58 months. Instability and deformity was detected in none of the patients on the flexion–extension lateral radiographs during the follow-up period. Conclusion These surgical approaches suitable for exploring and removing different intramedullary pathologies, help in preventing damage to crucial posterior stabilizers of the spine. Its major advantage is that unnecessary exposure and tissue trauma is reduced, and structures not directly involved in the pathologic process are preserved. In contrast to conventional spinal canal approaches, leaves the muscle attachments intact, disintegration of vertebral arches and facet joints is reduced. Furthermore, these techniques are suitable methods for all spinal segments in all age group. Although the clinical and radiological results are very promising, the limited follow-up period precludes conclusions regarding the long-term results of the procedure, especially with respect to kyphotic deformity.

Relative Contribution of Upper and Lower Lumbar Spinal Segments to Flexion/Extension: Comparison between Normal Spines and Spines with Disc Disease in Asian Patients.

Study DesignProspective cohort study.PurposeTo evaluate the contribution of upper and lower lumbar segments to flexion and extension of the lumbar spine in normal and diseased spines.Overview of LiteratureThe specific contributions of upper and lower lumbar segments during flexion/extension have rarely been reported. Furthermore, no comparisons between the flexion/extension behaviors of normal and diseased spines have been reported until now.MethodsFlexion and extension lateral radiographs of 52 adult, asymptomatic volunteers, and 67 adult patients with lumbar spine disc disease were measured using software for total lumbar lordosis, upper lumbar lordosis and lower lumbar lordosis and the intervertebral angles of all segments.ResultsIn asymptomatic volunteers, the range of movement between flexion and extension was a mean of only 4.2° in the lower lumbar spine and a mean of 19.4° in the upper lumbar spine. In patients with disc degeneration, the range of movement between flexion and extension was an average 6.5° for lower lumbar spine and 15.6° for the upper lumbar spine.ConclusionsThe results showed that upper lumbar spine contributes more to the range of motion in flexion and extension than the lower lumbar spine in asymptomatic individuals without lumbar disc disease, as well as in patients with disc degeneration.

Treatment of Irreducible Atlantoaxial Dislocation with C1-2 Sublaminar Cable-Dragged Reduction and Screw Fixation

Introduction Irreducible atlantoaxial dislocation (IAAD) is defined as the fixed displacement of C1-2 which is difficult to reach anatomic reduction, even with strong cranial skeletal traction under general anesthesia. The most frequently used method to treat symptomatic IAAD is transoral decompression or release combined with posterior fixation following preoperative cranial traction. However, those procedures are accompanied with high morbidity and mortality. We assumed that the inability to be reduced through cranial traction does not necessarily mean an irreducible dislocation, for the force exerted by cranial traction is oriented mainly upward, leading to an indirect reducing effect. Therefore, a new reduction strategy, called C1-2 sublaminar cable-dragged technique, has been developed to exert a straight backward force on the atlas to achieve an anatomic reduction followed by C1-2 screw fixation in a single stage via a posterior approach. The purpose of the present article is to report the early results of application of this method. Materials and Methods Thirty-two consecutive patients with IAAD, who underwent C1-2 posterior cable-dragged reduction and fixation, were retrospectively reviewed with minimum 2-year follow-up. Patient's mean age was 43.6 ± 19.4 years (range, 31-68). Anatomic reduction was achieved by passing a double 18-gauge titanium cable through the arch of C1 and lamina of C2. The cable was then retracted and tightened temporarily with a cable tensioner. Once satisfactory reduction was achieved and confirmed by C-arm radiography, fixation with C1 lateral mass screw and C2 pedicle screw was routinely performed. Then an autologous cancellous bone was grafted between the posterior arch of C1 and lamina of C2 using a modified Brooks-Jenkins procedure (Fig. 1). Lateral radiograph, 3D-CT, and MRI were obtained before surgery and at 3, 6, 12, and 24 months after surgery. Bony fusion was evaluated in flexion and extension lateral radiographs. Clinical symptoms were assessed with NDI and Frankel classification. Results The average follow-up period was 16.4 months. Radiographic evaluation of the group at follow-up showed 30 complete and 2 partial reductions, and satisfactory decompression in all cases (Fig. 2). Surgical complications, such as dural tear, laminar fracture, and spinal cord injury did not occur in any cases. The relief of occipital pain showed in 29 patients (90.6%). With regard to neurological recovery after surgery, 24 patients (75.0%) showed improvement by at least one level of Frankel criteria. Bony union was achieved in 31 patients (96.9%). Subaxial lesion occurred in four cases (12.5%), but additional surgery was not required in any cases. Conclusion Cable-dragged reduction and screw fixation are almost as effective for reduction as anterior release but is less invasive and risky. It could provide a high fusion rate and relief of pain. We suggest the use of a braided cable wire because it is soft and relatively safe to pass, resists fatigue well, and provides excellent fixation. However, there is little risk of vertebral artery and spinal cord injury. In conclusion, we recommend this new technique for IAAD patients with intact posterior arch of atlas. Disclosure of Interest None declared

Lumbar Stiffness Disability Index: pilot testing of consistency, reliability, and validity

Background contextThe primary goal of surgical arthrodesis is to eliminate the motion of spinal segments in an effort to alleviate pain, improve deformity, and reduce disability. However, decreased spinal mobility may impair performance of activities of daily living (ADLs) due to the resulting stiffness or the lack of mobility of the fused segment. Current clinical outcome instruments do not seek information regarding the impact of spinal stiffness on functional ability. Therefore, a patient-reported outcome questionnaire measuring the impact of lumbar stiffness on functional abilities was devised and assessed for internal consistency, retest repeatability, and external validity. PurposeTo develop and validate an outcome instrument to measure the collateral effect of stiffness after lumbar fusion on functional ability. Study designCross-sectional pilot study. Patient sampleConsecutive cohort of lumbar spine fusion patients from a single surgeon's practice. Outcome measuresLumbar Stiffness Disability Index (LSDI) and Cobb angle measurements from digital radiographs. MethodsWe developed and evaluated a 10-item questionnaire, referred to as the LSDI, which seeks information on the impact of spinal stiffness on ADLs after lumbar spinal arthrodesis. The questionnaire yields a score from 0 to 100, with higher scores indicating greater difficulty resulting from lumbar spinal stiffness in performing 10 different ADLs. The study sample comprised 32 lumbar arthrodesis patients at a minimum of 1 year postoperatively.All patients completed the questionnaire twice via telephone interviews conducted 4 weeks apart. Internal consistency was assessed using the Cronbach alpha, and retest reliability was measured using an intraclass correlation coefficient (ICC). External validity of the questionnaire was evaluated by correlating the scores with lumbar range of motion (LROM) as measured from the angular change between the inferior end plate of T12 and the superior end plate of S1 on standardized digital flexion and extension lateral radiographs. ResultsThe study sample included 22 women (69%) and 10 men (31%) with an average age of 63 years. The questionnaire demonstrated high internal consistency (Cronbach alpha=0.89). Retest reliability was also high (ICC=0.87). External validity was demonstrated by a statistically significant inverse relationship between LROM and LSDI scores (r=−0.71; p<.001). ConclusionsThis pilot study demonstrates that the LSDI questionnaire is a reliable and valid instrument for assessing functional limitations due to lumbar stiffness among spinal arthrodesis patients. The questionnaire is proposed for use in prospective evaluation of lumbar stiffness impacts after arthrodesis.

Usefulness of Prone Cross-Table Lateral Radiographs in Vertebral Compression Fractures

BackgroundDynamic radiographs are recommended to investigate non-healing evidence such as the dynamic mobility or intravertebral clefts in osteoporotic vertebral compression fractures (VCFs). However, it is difficult to examine standing flexion and extension lateral radiographs due to severe pain. The use of prone cross-table lateral radiographs (PrLRs) as a diagnostic tool has never been proposed to our knowledge. The purpose of this study is to clarify the usefulness of PrLRs in diagnosis and treatment of VCFs.MethodsWe reviewed 62 VCF patients examined with PrLRs between January 1, 2008 and June 30, 2011. To compare the degree of pain provoked between standing extension lateral radiographs (StLRs) and PrLRs, numeric rating scale (NRS) scores were assessed and compared by a paired t-test. Vertebroplasty was done for 40 patients and kyphoplasty was done for 9 patients with routine manners. To assess the degree of postural reduction, vertebral wedge angles (VWA) and vertebral height ratios (VHR) were calculated by using preoperative StLRs, PrLRs, and postoperative lateral radiographs. Two variables derived from changes in VWA and VHR between preoperative and postoperative radiographs were compared by a paired t-test.ResultsThe average NRS scores were 6.23 ± 1.67 in StLRs and 5.18 ± 1.47 in PrLRs. The degree of pain provocation was lower in using PrLRs than StLRs (p < 0.001). The average changes of VWA between preoperative and postoperative status were 5.24° ± 6.16° with PrLRs and 3.46° ± 3.47° with StLRs. The average changes of VHR were 0.248 ± 0.178 with PrLRs and 0.148 ± 0.161 with StLRs. The comparisons by two variables showed significant differences for both parameters (p = 0.021 and p < 0.001, respectively). The postoperative radiological status was reflected more precisely when using PrLRs than StLRs.ConclusionsIn comparison with StLR, the PrLR was more accurate in predicting the degree of restoration of postoperative vertebral heights and wedge angles, and provoked less pain during examination. The PrLR could be a useful diagnostic tool to detect intravertebral cleft or intravertebral dynamic instability.

Artificial Disk Replacement Combined With Midlevel ACDF Versus Multilevel Fusion for Cervical Disk Disease Involving 3 Levels

The optimal surgical approach for cervical disk disease remains a matter of debate, especially for multilevel disease. The purpose of this study was to compare the results of 2 surgical strategies for cervical disk disease involving 3 levels: hybrid constructs, artificial disk replacement combined with midlevel anterior cervical diskectomy and fusion (ACDF), and 3-level ACDF. The authors prospectively compared patients who had cervical disk disease involving 3 levels that was treated with hybrid constructs or with 3-level ACDF. Patients were asked to use the Neck Disability Index (NDI) to grade their pain intensity preoperatively and at routine postoperative intervals of 1, 3, 6, 12, and 24 months. Dynamic flexion and extension lateral cervical radiographs were obtained while in the standing position preoperatively and at the postoperative intervals. The angular range of motion for C2-C7 and the adjacent segments was measured using the Cobb method. Twenty-four patients were treated, 12 with hybrid constructs and 12 with 3-level ACDF. Both groups had significant postoperative improvement in NDI scores and neck pain (P<.05). However, no significant difference was found between the groups (P>.05). The hybrid constructs group showed faster recovery of C2-C7 range of motion. Mean C2-C7 range of motion of the hybrid constructs group recovered to that of the preoperative value, but that of the 3-level ACDF group did not (P<.05). Range of motion of the superior and inferior adjacent segments showed significant differences between the 2 groups at 12 and 24 months postoperatively (P<.05). These findings suggest that the hybrid constructs is a safe and effective alternative for cervical disk disease involving 3 levels. The definite stabilization and maintained range of motion can be achieved right away, which can ensure a good preliminary clinical outcome.

Modified Surgical Approach to Cervical Neurinomas with Intraforaminal Components: Minimal Invasive Facet Joint Sparing “Open-Tunnel” Technique

The conventional posterior approaches, which may involve multilevel laminectomies and facetectomies, may lead to spinal deformities, instability, or subluxation. Our objective was to develop a minimally invasive approach suitable for exploring neuromas with an intraforaminal component in the cervical spine, with the aim of preserving mechanically relevant bone structures and the facet joints as much as possible. The authors used the hemi-semi-laminectomy combined with partial lateral facetectomy "open-tunnel" technique in nine adult patients with neuromas of the cervical spine extending into the foramen. The operating field under the operating microscope was sufficient for tumor removal according to the keyhole concept. The approach did not affect the extent of tumor resection or neurological outcome. Complete removal was achieved in all patients, as confirmed by magnetic resonance imaging (MRI). The affected nerve roots included C3 in three cases, C2 and C4 in two, and C5 and C6 in one case. Average follow-up was 12 months, with a range from 8 to 18 months. Histological results were as follows: six schwannomas and three neurofibromas. Computed tomographic scans demonstrated the extension of the keyhole approaches and the moderately affected bony structures and facet joints. Instability was detected in none of the patients on the flexion or extension lateral radiographs during the follow-up period. This modified surgical approach fulfills the requirements of other minimally invasive techniques and lowers the risk of damage to the crucial posterior stabilizers of the spine; furthermore, disintegration of vertebral arches and facet joints is reduced. The approach is suitable for exploring and removing neuromas located in the spinal canal and in the neuroforamen.

Clinical outcomes of Hybrid-surgery to treat the two-level cervical disease

To evaluate the clinical and radiologic outcomes of the Hybrid surgery (cervical artificial disc replacement combined with anterior cervical discectomy and fusion (ACDF)) and the effective of the adjacent segment. Between December 2007 to June 2010, 34 patients underwent 2-level cervical disc surgery. There were 17 patients underwent Hybrid surgery (Hybrid group), 17 patients underwent 2-level ACDF (ACDF group). Japanese orthopaedic association (JOA), neck disability index (NDI), and Odom's standards were evaluated. Dynamic flexion and extension lateral cervical radiographs were obtained in the standing position before surgery and at routine postoperative intervals of 1, 3, 6 months. Both of the two groups had significantly improvement than preoperative in JOA (t = -8.790 - -5.803, P < 0.05) and NDI scores (t = 10.717 - 13.514, P < 0.05), but no significantly difference between the two groups (P > 0.05). Both of the two groups had significantly decreased in the mean C(2-7) range of motion (ROM). The Hybrid group decreased from 46° ± 11° preoperative to 41° ± 8° at the 6 mouths after surgery (t = 3.170, P < 0.05). The ACDF group decreased from 45° ± 13° preoperative to 38° ± 15° at the 6 mouths after surgery (t = 6.709, P < 0.05). But there were no significantly difference between the two groups (P > 0.05). In the Hybrid group, both the superior adjacent segment ROM and the inferior adjacent segment ROM were decreased in the follow-up, there had significantly difference at the 1 and 3 months after surgery (superior adjacent segment: t = 5.622 and 4.032, P < 0.05; inferior adjacent segment: t = 2.879 and 2.207, P < 0.05), but no significantly difference after 6 months (P > 0.05). In the ACDF group, the ROM of the inferior adjacent segment was significantly increased at 3 and 6 months after surgery (t = -7.038 and -13.540, P < 0.05), the ROM of the superior adjacent segment was significantly increased at 6 months after surgery (t = -2.453, P < 0.05). Hybrid surgery has excellent clinical results and decreases the ROM of the adjacent segment in the following 6 months, meanwhile 2-level ACDF increases the ROM of the adjacent segment. The long-term clinical outcomes of the Hybrid surgery need more study.

Minimally invasive anterior transarticular screw fixation and microendoscopic bone graft for atlantoaxial instability

Even though transarticular screw (TAS) fixation has been commonly used for posterior C1-C2 arthrodesis in both traumatic and non-traumatic lesions, anterior TAS fixation C1-2 is a less invasive technique as compared with posterior TAS which produces significant soft tissue injury, and there were few reports on percutaneous anterior TAS fixation and microendoscopic bone graft for atlantoaxial instability. The goals of our study were to describe and evaluate a new technique for anterior TAS fixation of the atlantoaxial joints for traumatic atlantoaxial instability by analyzing radiographic and clinical outcomes. This was a retrospective study of seven consecutive patients with C1-C2 instability due to upper cervical injury treated by a minimally invasive procedure from May 2007 to August 2009. Bilateral anterior TAS were inserted by the percutaneous approach under Iso-C3D fluoroscopic control. The atlantoaxial joint space was prepared for morselized autogenous bone graft under microendoscopy. The data for analysis included time after the injuries, operating time, intraoperative blood loss, X-ray exposure time, clinical results, and complications. Radiographic evaluation included the assessment of atlantoaxial fusion rate and placement of TAS. Bone fusion of the atlantoaxial joints was assessed by flexion extension lateral radiographs and 1-mm thin-slice computed tomography images as radiographic results. Clinical assessment was done by analyzing the recovery state of clinical presentation from the preoperative period to the last follow-up and by evaluating complications. A total of 14 screws were placed correctly. The atlantoaxial solid fusion without screw failure was confirmed by CT scan in seven cases after a mean follow-up of 27.5 months (range 18-45 months). All patients with associated clinical presentation made a recovery without neurologic sequelae. Postoperative dysphagia occurred and disappeared in two cases within 5 days after surgery. There were no other complications during the follow-up period. Percutaneous anterior TAS fixation and microendoscopic bone graft could be an option for achieving C1-C2 stabilization with several potential advantages such as less tissue trauma and better accuracy. Bilateral TAS fixation and morselized autograft affords effective fixation and solid fusion by a minimally invasive approach.

A radiographic analysis of degenerative spondylolisthesis at the L4–5 level

Lumbar degenerative spondylolisthesis (LDS) is common and has generally been characterized as a homogeneous disease entity in the literature and in clinical practice. Because disease variability has not been carefully characterized, stratification of treatment recommendations based on scientific evidence is currently lacking. In this study, the authors analyzed radiographic parameters of patients with LDS at the L4-5 level to better characterize this entity. Demographic data were collected from 304 patients (200 women and 104 men) with LDS at the L4-5 level. Plain radiographs including anteroposterior, lateral, and flexion-extension lateral radiographs were analyzed for disc height, segmental angulation, segmental translation, and osteophyte formation. Correlations were sought between the variables of age, sex, disc height, segmental angulation, segmental translation, and osteophyte formation. The mean patient age was 63.8 years (range 40-86 years). The mean mid-disc height was 7 mm (range 0-14 mm) on the neutral lateral view. The mean angulation between the superior endplate of L-5 and the inferior endplate of L-4 was 6° of lordosis (range 13° of kyphosis to 23° lordosis) on the neutral lateral view. The mean angular change between flexion and extension lateral radiographs was 5° (range 0°-17°). The mean translation on the neutral lateral view was 6 mm (range 0-15 mm). The mean change in translational between flexion and extension was 2 mm (range 0-11 mm). Twenty patients (7%) exhibited spondylolisthesis only on the flexion view. A significant positive correlation was found between the change in angulation and the change in translation on flexion and extension views (ρ = 0.18, p = 0.001). No significant correlation was found between anterior osteophyte size and mobility with flexion-extension radiographs. The wide range in all radiographic parameters for LDS confirms the heterogeneous nature of this condition and suggests that a grading system to subclassify LDS may be clinically useful. On flexion and extension radiographs, increased translational motion correlated with increased angular motion. Anterior osteophyte size was not found to be predictive of segmental stability. This data set should prove beneficial to those seeking to subcategorize LDS in the future.