Flexion-extension Radiographs Research Articles

The Relationship Between MRI Findings of Posterior Ligamentous Complex and Lumbar Instability in Degenerative Spondylolisthesis.

To determine the factors in posterior ligamentous complex indicating lumbar instability in patients diagnosed with degenerative spondylolisthesis on conventional magnetic resonance imaging (MRI). We retrospectively analyzed patients who underwent PLIF surgery for degenerative spondylolisthesis at our institution between 2018 and 2020 and who had complete eligible preoperative imaging data for review and study, including lumbar MRI and anteroposterior and flexion-extension radiographs. Fifty-three patients were confirmed to have lumbar instability (Unstable Group, 44%), while sixty-seven patients (Stable Group, 56%) did not have instability on radiographs. The patients in the stable group had more advanced status of the degeneration of intervertebral disc than in the unstable group (p<0.05). The degeneration of supraspinous ligament (SSL) was more severe in the unstable group (p<0.05). Compared with the patients with rotatory instability, advanced degeneration of interspinous ligament (ISL) and SSL was observed in patients with translatory instability (p<0.05). However, there was no significant difference with regard to the height of the spinous process and the interspinous distance in patients with or without instability. This MRI analysis showed that abnormal segmental motion is closely associated with the pathological characteristics of supraspinal ligament. Advanced degeneration of SSL in patients with degenerative spondylolisthesis should raise the suspicion for lumbar instability and additional evaluations. The status of ISL and ligamentum flavum (LF) may not be helpful for the diagnosis of lumbar instability. Functional radiographs combined with MRI may provide valuable information when diagnosing lumbar instability in patients with mechanical back pain.

Interbody Fusion Device in the Treatment of Cervicobrachial Syndrome: A Prospective 5-Year Follow-Up Extension Study of Porous Titanium Cervical Cages

Background: To assess long-term clinical and radiological data of porous titanium cervical interbody cages. Methods: We recruited 34 out of 49 patients previously enrolled in the EFFECT trial on 3D printed titanium cages, for 5 years follow-up. Objectives were the evaluation of Neck Disability Index, Visual Analog Scale of arm pain and neck pain, Likert self-reported perceived recovery, EQ-5D, fusion status and subsidence. Fusion was defined as rotation ≤ 4° and ≤ 1.25 mm translation at the index level, using flexion-extension radiograph. Results: All patients had good outcomes in terms of NDI (12.5±15.4), VAS neck pain (23.5±24.1), VAS arm pain (18.7±20.2) and EuroQol (0.77±0.24). 88.6% of the patients experienced complete or nearly complete recovery. NDI improved significantly at 5 years compared to 1 year, all other outcome measures did not significantly differ from the 12 months results. The fusion rate at the index level increased from 91.5% at 12 months to 100% at 5 years. Conclusion: 3D printed stand-alone porous titanium cervical implants are effective in terms of clinical and radiological outcome with 88.6% complete or nearly complete recovery and fusion rate of 100% at 5 years follow-up. Moreover, solid single level anterior cervical fusion can be achieved without additional plating. Trial Registration: The study has been registered in The Netherlands Trial Register (NTR 1289) and approved by the Medical Ethical Committee (NL76079.058.20).

Interim 1-Year Radiographic and Clinical Outcomes Following Anterior Cervical Discectomy and Fusion Using Hydroxyapatite-Infused Polyetheretherketone Interbody Cages.

This is a multicenter observational registry analysis of 1-year radiographic and clinical outcomes following anterior cervical discectomy and fusion (ACDF) using hydroxyapatite (HA)-infused polyetheretherketone (PEEK) intervertebral cages. Radiographic and clinical outcome data were collected preoperatively and at 6 weeks, 3 months, 6 months, and 12 months postoperatively. To assess fusion, dynamic flexion-extension radiographs were independently evaluated with a validated method. Clinical outcomes were assessed using the following disease-specific measures: Neck Disability Index (NDI) and visual analog scale (VAS) for neck, left arm, and right arm pain. Patient satisfaction was also evaluated. A total of 789 ACDF patients (men: 51.5%/women: 48.5%; mean body mass index: 29.9 kg/m2) were included at the time of analysis, and 1565 segments have been operated. Successful fusion was confirmed in 91.3% of all operated levels after 6 months and 92.2% after 12 months. Mean NDI scores improved significantly (P < 0.01) preoperatively (46.3, n = 771) to postoperatively (12 months: 25.2, n = 281). Consistently, mean VAS neck (preoperative: 64.2, n = 770; 12 months: 28.6, n = 278), VAS right arm (preoperative: 42.6, n = 766; 12 months: 20.4, n = 277), and VAS left arm (preoperative: 41.1, n = 768; 12 months: 20.8, n = 277) decreased significantly (P < 0.01). Patients reported high satisfaction rates after surgery with no significant changes in postoperative patient satisfaction between 6 weeks and 12 months (95.1%, n = 273). ACDF with HA-infused PEEK cages demonstrates promising radiographic and clinical outcomes, supporting the potential benefits of incorporating HA into PEEK cages to enhance fusion rates and improve patient outcomes. This study demonstrates a >90% fusion rate by level with reliable improvements in patient reported outcomes, along with a high rate of patient satisfaction, in a large patient cohort undergoing ACDF with HA-infused PEEK cages. 2 .

Clinical Utility of An Intervertebral Motion Metric for Deciding on the Addition of Instrumented Fusion in Degenerative Spondylolisthesis.

A prospective single-arm clinical study. To explore the clinical utility of an intervertebral motion metric by determining the proportion of patients for whom it changed their surgical treatment plan from decompression only to decompression with fusion or vice versa. Lumbar spinal stenosis (LSS) from degenerative spondylolisthesis is commonly treated with decompression only or decompression with additional instrumented fusion. An objective diagnostic tool capable of establishing abnormal motion between lumbar vertebrae to guide decision-making between surgical procedures is needed. To this end a metric, based on the vertebral sagittal plane translation-per-degree-of-rotation (TPDR) calculated from flexion-extension radiographs, was developed. First, spine surgeons documented their intended surgical plan. Subsequently, the participants' flexion-extension radiographs were taken. From these the TPDR was calculated and reported as a Sagittal Plane Shear Index (SPSI). The SPSI metric of the spinal level intended to treat was used to decide if the intended surgical plan needed to be changed or not. SPSI was determined for 75 participants. Of these, 51 (68%) had an intended surgical plan of decompression only and 24 (32%) decompression with fusion. In 63% of participants the SPSI was in support of their intended surgical plan. For 29% of participants the surgeon changed the surgical plan after the SPSI metric became available to them. A suggested change in surgical plan was overruled in 8% of participants. The final surgical plan was decompression only for 59 (79%) and decompression with fusion for 16 (21%) participants. The 29% change in intended surgical plans suggested that SPSI was considered by spine surgeons as an adjunct metric in deciding whether to perform decompression only or or to add instrumented fusion. This change exceeded the a priori defined 15% considered necessary to show potential clinical utility of SPSI.

Preoperative and Postoperative Segmental and Overall Range of Motion in Patients Undergoing Lumbar Spinal Fusion Using HA-Infused PEEK and HA-Treated Titanium Alloy Interbody Cages.

Retrospective observational radiographic analysis. Determine how single level lumbar interbody fusion (LIF) alters segmental range of motion (ROM) at adjacent levels and decreases overall ROM. This study included 54 patients who underwent single-level anterior (ALIF, 39%), thoraco-LIF (TLIF, 26%), posterior LIF (PLIF, 22%), or lateral LIF (LLIF, 13%) (L2-3/L3-4/L4-5/L5-S1: 4%/13%/35%/48%). Segmental ROM from L1-2 to L5-S1 and the overall lumbar ROM (L1-S1) were assessed from preoperative and postoperative flexion-extension radiographs. K-means cluster analysis was used to identify ROM subgroups. The overall L1-S1 ROM decreased 14% (25.5 ± 20.4° to 22.0 ± 17.2°, P = .104) postoperatively. ROM at the fusion level decreased 77% (4.8 ± 5.0° to 1.1 ± 1.1°, P < .001). Caudal adjacent segment ROM decreased 12% (5.2 ± 5.7° to 4.6 ± 4.4°, P = .345) and cranially ROM increased 34% (4.3 ± 5.0° to 5.7 ± 5.7°, P = .05). K-cluster analysis identified 3 distinct clusters (P < .05). Cluster 1 lost more ROM and had less improvement in patient-reported outcomes measures (PROMs) than average. Cluster 2 had less ROM loss than average with worse PROMs improvement. Cluster 3 did not have changes in ROM and better improvement in PROMs than average. Successful fusion was verified in 96% of all instrumented segments with >6months follow-up (ROM <4°). Following single-level L IF, patients should expect a loss of 3.3°, or 14% of overall lumbar motion with increases in ROM of the cranial segment. However, specific clusters of patients exist that experience different relative changes in ROM and PROMs.

The Impact of Cervical Degeneration and Sagittal Balance on Retro-Odontoid Soft-Tissue Thickness

ObjectiveTo investigate whether retro-odontoid soft-tissue thickness (ROSTT) is associated with cervical degeneration, cervical spine mobility, and sagittal balance of cervical spine. MethodsThe data of 151 patients who presented at our hospital with cervical spondylosis were reviewed. The ROSTT was measured using T1-weighted sagittal cervical MRI fundings. The assessment of the degree of cervical intervertebral disc degeneration (IVDD) was conducted using sagittal T2-weighted imaging. The T1 slope (T1S), C1–C2 angle, C2−C7 angle, C1−C7 sagittal vertical axis (SVA) and C2−C7 SVA were measured. The range of motion (ROM) was assessed by measuring the flexion-extension radiographs. According to the ROSTT, those measuring less than 3mm were classified as normal group and those measuring larger than 3mm were classified as thickened group. ResultsThe thickened group had larger cervical IVDD grade, age, C2−C7 angle, and T1S compared to the normal group (all P<0.05). Additionally, the C0−2 angle was significantly smaller in the thickened group than in the normal group (P<0.05). ROSTT showed a negative correlation with C0−C2 angle (r=-0.181, P<0.05), but positive correlations with both C2−C7 angle (r=0.255, P<0.05) and T1S (r=0.240, P<0.05). Furthermore, ROSTT was positively correlated with age (r=0277, P<0.05) and cervical IVDD grade (Spearman, r=0.299, p<0.05). ConclusionsCervical sagittal balance and cervical degeneration have a significant impact on ROSTT. Patients with a higher T1S and severe cervical degeneration are more likely to result in greater ROSTT.

Utility of a 2D kinematic HASTE sequence in magnetic resonance imaging assessment of adjacent segment degeneration following anterior cervical discectomy and fusion.

To evaluate a dynamic half-Fourier acquired single turbo spin echo (HASTE) sequence following anterior cervical discectomy and fusion (ACDF) at the junctional level for adjacent segment degeneration comparing dynamic listhesis to radiographs and assessing dynamic cord contact and deformity during flexion-extension METHODS: Patients with ACDF referred for cervical spine MRI underwent a kinematic flexion-extension sagittal 2D HASTE sequence in addition to routine sequences. Images were independently reviewed by three radiologists for static/dynamic listhesis, and compared to flexion-extension radiographs. Blinded assessment of the HASTE sequence was performed for cord contact/deformity between neutral, flexion, and extension, to evaluate concordance between readers and inter-modality agreement. Inter-reader agreement for dynamic listhesis and impingement grade and inter-modality agreement for dynamic listhesis on MRI and radiographs was assessed using the kappa coefficient and percentage concordance. A total of 28 patients, mean age 60.2 years, were included. Mean HASTE acquisition time was 42 s. 14.3% demonstrated high grade dynamic stenosis (> grade 4) at the adjacent segment. There was substantial agreement for dynamic cord impingement with 70.2% concordance (kappa = 0.62). Concordance across readers for dynamic listhesis using HASTE was 81.0% (68/84) (kappa = 0.16) compared with 71.4% (60/84) (kappa = 0.40) for radiographs. Inter-modality agreement between flexion-extension radiographs and MRI assessment for dynamic listhesis across the readers was moderate (kappa = 0.41; 95% confidence interval: 0.16 to 0.67). A sagittal flexion-extension HASTE cine sequence provides substantial agreement between readers for dynamic cord deformity and moderate agreement between radiographs and MRI for dynamic listhesis. Degeneration of the adjacent segment with instability and myelopathy is one of the most common causes of pain and neurological deterioration requiring re-operation following cervical fusion surgery. • A real-time kinematic 2D sagittal HASTE flexion-extension sequence can be used to assess for dynamic listhesis, cervical cord, contact and deformity. • The additional kinematic cine sequence was well tolerated and the mean acquisition time for the 2D HASTE sequence was 42 s (range 31-44 s). • A sagittal flexion-extension HASTE cine sequence provides substantial agreement between readers for dynamic cord deformity and moderate agreement between radiographs and MRI for dynamic listhesis.

Utility of Seated Lateral Radiographs in the Diagnosis and Classification of Lumbar Degenerative Spondylolisthesis.

Retrospective cohort study. Our goal was to determine which radiographic images are most essential for degenerative spondylolisthesis (DS) classification and instability detection. The heterogeneity in DS requires multiple imaging views to evaluate vertebral translation, disc space, slip angle, and instability. However, there are several restrictions on frequently used imaging perspectives such as flexion-extension and upright radiography. We assessed baseline neutral upright, standing flexion, seated lateral radiographs, and magnetic resonance imaging (MRI) for patients identified with spondylolisthesis from January 2021 to May 2022 by a single spine surgeon. DS was classified by Meyerding and Clinical and Radiographic Degenerative Spondylolisthesis classifications. A difference of >10° or >8% between views, respectively, was used to characterize angular and translational instability. Analysis of variance and paired chi-square tests were utilized to compare modalities. A total of 136 patients were included. Seated lateral and standing flexion radiographs showed the greatest slip percentage (16.0% and 16.7%), while MRI revealed the lowest (12.2%, p <0.001). Standing flexion and lateral radiographs when seated produced more kyphosis (4.66° and 4.97°, respectively) than neutral upright and MRI (7.19° and 7.20°, p <0.001). Seated lateral performed similarly to standing flexion in detecting all measurement parameters and categorizing DS (all p >0.05). Translational instability was shown to be more prevalent when associated with seated lateral or standing flexion than when combined with neutral upright (31.5% vs. 20.2%, p =0.041; and 28.1% vs. 14.6%, p =0.014, respectively). There were no differences between seated lateral or standing flexion in the detection of instability (all p >0.20). Seated lateral radiographs are appropriate alternatives for standing flexion radiographs. Films taken when standing up straight do not offer any more information for DS detection. Rather than standing flexion-extension radiographs, instability can be detected using an MRI, which is often performed preoperatively, paired with a single seated lateral radiograph.

Measurement of interspinous motion in dynamic cervical radiographs using a deep learning-based segmentation model.

Interspinous motion (ISM) is a representative method for evaluating the functional fusion status following anterior cervical discectomy and fusion (ACDF) surgery, but the associated measuring difficulty and potential errors in the clinical setting remain concerns. The aim of this study was to investigate the feasibility of a deep learning-based segmentation model for measuring ISM in patients who underwent ACDF surgery. This study is a retrospective analysis of flexion-extension dynamic cervical radiographs from a single institution and a validation of a convolutional neural network (CNN)-based artificial intelligence (AI) algorithm for measuring ISM. Data from 150 lateral cervical radiographs from the normal adult population were used to train the AI algorithm. A total of 106 pairs of dynamic flexion-extension radiographs from patients who underwent ACDF at a single institution were analyzed and validated for measuring ISM. To evaluate the agreement power between human experts and the AI algorithm, the authors assessed the interrater reliability using the intraclass correlation coefficient and root mean square error (RMSE) and performed a Bland-Altman plot analysis. They processed 106 pairs of radiographs from ACDF patients into the AI algorithm for autosegmenting the spinous process created using 150 normal population radiographs. The algorithm automatically segmented the spinous process and converted it to a binary large object (BLOB) image. The rightmost coordinate value of each spinous process from the BLOB image was extracted, and the pixel distance between the upper and lower spinous process coordinate value was calculated. The AI-measured ISM was calculated by multiplying the pixel distance by the pixel spacing value included in the DICOM tag of each radiograph. The AI algorithm showed a favorable prediction power for detecting spinous processes with an accuracy of 99.2% in the test set radiographs. The interrater reliability between the human and AI algorithm of ISM was 0.88 (95% CI 0.83-0.91), and its RMSE was 0.68. In the Bland-Altman plot analysis, the 95% limit of interrater differences ranged from 0.11 to 1.36 mm, and a few observations were outside the 95% limit. The mean difference between observers was 0.02 ± 0.68 mm. This novel CNN-based autosegmentation algorithm for measuring ISM in dynamic cervical radiographs showed strong agreement power to expert human raters and could help clinicians to evaluate segmental motion following ACDF surgery in clinical settings.

Transforaminal Full-Endoscopic Ventral Facetectomy: Midterm Results and Factors Associated with Poor Surgical Outcomes.

Full-endoscopic spine surgery (FESS) is a well-established procedure for herniated nucleus pulposus. It is a minimally invasive surgery that can be performed under local anesthesia through only an 8-mm skin incision. With improvements in surgical equipment such as high-speed drills, the indications for FESS have expanded to include lumbar spinal stenosis (LSS). We perform a transforaminal full-endoscopic ventral facetectomy (TF-FEVF) for unilateral nerve root-type lateral recess stenosis (LRS) using a transforaminal approach under local anesthesia.The aim of this study was to examine the postoperative results of TF-FEVF for LRS and to identify factors associated with poor surgical outcomes. 85 patients who underwent TF-FEVF for LRS under local anesthesia. Clinical outcomes were determined by visual analog scale (VAS) and the modified MacNab criteria. Evaluation was performed using magnetic resonance imaging (MRI), computed tomography (CT), and flexion-extension radiographs. This study involved 85 patients (47 males and 38 females) who underwent TF-FEVF for LRS. The mean age was 70.5 years and the mean follow-up duration was 14.8 months. Data were collected on sex, age, level of operation, diagnosis, history of spine surgery at the same level, and duration of follow-up. The diagnosis was categorized as LSS with or without disk bulging. Clinical evaluation was performed using the VAS and modified MacNab criteria. MRI was used to evaluate the degree of disk degeneration, vertebral endplate degeneration, disk height, thickening of the ligamentum flavum, and stenosis. Bony stenosis was evaluated using CT. Sagittal translation and sagittal angulation were also measured by flexion-extension radiographs, and the Cobb angle was measured using a standing front view radiograph. All variables were compared between patients with excellent/good outcomes (E/G group) and those with fair/poor outcomes (F/P group) using the modified MacNab criteria. Postoperative VAS showed that leg pain decreased from 59.0 ± 28.6 preoperatively to 17.9 ± 27.2 at the final follow-up (p < 0.01) and that lower back pain also decreased from 60.7 ± 26.6 preoperatively to 27.3 ± 28.6 at final follow-up (p < 0.01). According to the modified MacNab criteria, the results during the final follow-up were excellent in 39 cases, good in 21 cases, fair in 13 cases, and poor in 12 cases. There were no significant differences in sex, age, diagnosis, history of spine surgery, and duration of follow-up periods between the 60 cases (70.6%) in the E/G group and the 25 cases (29.4%) in the F/P group. Imaging evaluation revealed statistically significant differences between the E/G group and the F/P group in intervertebral angle flexion (3.2 vs. 0.4 degrees; p < 0.05), sagittal angulation (4.3 vs. 8.1 degrees; p < 0.05), slip in flexion (0.9 vs. 2.8 mm; p < 0.05), sagittal translation (0.7 vs. 1.6 mm; p < 0.05), and Cobb angle (-0.5 vs. -1.9 degrees; p < 0.05). Midterm results of TF-FEVF were generally favorable; factors contributing to good or poor TF-FEVF outcomes were large sagittal angulation, large sagittal translation, and concave side.

Cervical spine flexion-extension radiography versus magnetic resonance imaging in pediatric patients following blunt traumatic injury

BackgroundIn pediatric trauma patients, 60–80% of spinal cord injuries involve the cervical vertebrae. While the American College of Radiology offers guidelines for best imaging practices in the setting of acute...

Evaluation of segmental mobility in patients with lumbar spondylolisthesis : A comparison of images from standing flexion-extension and standing/supine slippage

To evaluate segmental mobility with degenerative lumbar spondylolisthesis (DLS), upright lateral flexion-extension radiographs (FE) are widely used. However, some authors have described that a combination of lateral radiographs in the standing position and supine sagittal image (SS) reveal more segmental mobility than FE. The purpose of this study was to investigate the optimal method for evaluating segmental mobility with DLS.We included 92 consecutive Japanese patients diagnosed with DLS. Sagittal translation (ST) determined by FE and SS were compared. Pathological instability was defined as ST more than 8% of the upper vertebra. Patients were divided into those diagnosed with pathological instability in FE (PI-FE) and those diagnosed with SS (PI-SS), and lumbar lordosis (LL) in the standing position in each group were compared.ST in FE was significantly greater than in SS. Of 92 patients, 31 had pathological instability in FE or SS ; 17 patients had PI-FE, and 10 patients had PI-SS. LL in the standing position in PI-FE was significantly smaller than in PI-SS.ST in FE was greater than that in SS, contrary to previous studies' reports on Caucasians. Since Japanese individuals have smaller LL than Caucasians, FE tends to reveal more segmental mobility than SS. J. Med. Invest. 70 : 135-139, February, 2023.

Use of biphasic calcium phosphate versus demineralized bone matrix: retrospective clinical and CT analysis of posterolateral fusion results.

Bone graft extenders have been developed to prevent donor site morbidity associated with iliac crest bone graft, but few studies compared the efficacy of various substitutes. Our purpose was to determine fusion rate and clinical outcome in patients undergoing lumbar arthrodesis using demineralized bone matrix (DBM) and biphasic calcium phosphate (BCP). Patients with degenerative spondylolisthesis undergoing one-level or two-level arthrodesis of lumbar spine were retrospectively reviewed. Two treatment groups placed either BCP or DBM, in addition to local autograft in lumbar posterolateral space. Three-dimensional CT exam and dynamic flexion-extension radiographs at postoperative 2-year were assessed for posterolateral fusion status and pain scale and Oswestry Disability Index (ODI) for clinical outcome. Of the 148 patients reviewed (including 23 in one- and 58 patients in two-level in BCP group, and 47 in one- and 20 patients in two-level in DBM group), no significant differences were found in terms of age, sex, BMI, smoking, diabetes, steroids, number of level fused, non-union rate or revision surgery between BCP and DBM groups. Significantly improved pain scale of back and leg and ODI were found in both groups postoperatively without group difference. We found a comparable fusion rate in one-level surgery (100% versus 93.6%) and a superior fusion rate of BCP group in two-level surgery (98.3% versus 80.0%, p = 0.01). Being a bone graft extender without osteoinductive property, with local autograft, BCP is comparable to DBM for one- and superior for two-level fusion. No significant difference was found in clinical outcomes.

Preliminary Results of Instantaneous Centre of Rotation Change after Thoracic Instrumentation in Adolescent Idiopathic Scoliosis Patients.

The instantaneous centre of rotation (ICR) is the centre of motion with zero velocity where a rigid body moves in a particular plane. ICR, as a dynamic measurement, gives more accurate results in terms of quality and quantity of the vertebral motions compared to range of motion (ROM). We aimed to determine the effect of thoracic instrumentation on cervical movement of adolescent idiopathic scoliosis (AIS) patients who had undergone thoracic level instrumentation by measuring pre-operative and post-operative ICR change in a pilot study. A total of 25 AIS patients were included in this study. C4-C5 and C6-C7 segmental ICR were determined by pre-operative and post-operative cervical flexion-extension radiographs. In addition, cervical sagittal parameters and global sagittal parameters were investigated. There was no statistically significant change in ICR location post-operatively in both x and y coordinates at C4-C5 segment (p: 0.326 and p: 0.946, respectively) and C6-C7 segment (p: 0.209, p: 0.086, respectively). There was a positive correlation between LCL and C4-C5 ICR y coordinate (r: 0.481), but not with C6-C7 ICR y coordinate (r: -0.2, p: 0.398). T5-T12 kyphosis decreased (p: 0.002) and T1 pelvic angle (0.003), SVA (0.02) and sacral slope (0.049) increased significantly post-operatively. T1S was correlated with LCL (r: 0.595, p: 0.002), T5-T12 kyphosis (r: 0.423, p: 0.035), SVA (r: 0.658, p<0.001) and C2-C7 SVA (r: 0.416, p: 0.039). The ICR for cervical region was not changed post-operatively in AIS patients with thoracic instrumentation. There was no relationship found between the development of post-operative cervical kyphosis or lordosis and ICR, which represents the quality and quantity of intervertebral motion. The T1 vertebra plays a key role for cervical, thoracic, and global parameters interaction.

Utility of a fulcrum for positioning support during flexion-extension radiographs for assessment of lumbar instability in patients with degenerative lumbar spondylolisthesis.

The authors investigated a new standardized technique for evaluating lumbar stability in lumbar lateral flexion-extension (LFE) radiographs. For patients with lumbar spondylolisthesis, a three-part fulcrum with a support platform that included a semiarc leaning tool with armrests, a lifting platform for height adjustment, and a base for stability were used. Standard functional radiographs were used for comparison to determine whether adequate flexion-extension was acquired through use of the fulcrum method. A total of 67 consecutive patients diagnosed with L4-5 degenerative lumbar spondylolisthesis were enrolled in the study. The authors analyzed LFE radiographs taken with the patient supported by a fulcrum (LFEF) and without a fulcrum. Sagittal translation (ST), segmental angulation (SA), posterior opening (PO), change in lumbar lordosis (CLL), and lumbar instability (LI) were measured for comparison using functional radiographs. The average value of SA was 5.76° ± 3.72° in LFE and 9.96° ± 4.00° in LFEF radiographs, with a significant difference between them (p < 0.05). ST and PO were also significantly greater in LFEF than in LFE. The detection rate of instability was 10.4% in LFE and 31.3% in LFEF, and the difference was significant. The CLL was 27.31° ± 11.96° in LFE and 37.07° ± 12.963.16° in LFEF, with a significant difference between these values (p < 0.05). Compared with traditional LFE radiographs, the LFEF radiographs significantly improved the detection rate of LI. In addition, this method may reduce patient discomfort during the process of obtaining radiographs.

Lumbosacral transitional vertebrae alter the distribution of lumbar mobility-Preliminary results of a radiographic evaluation.

BackgroundLumbo-sacral transitional vertebrae (LSTV) are one of the most common congenital variances of the spine. They are associated with an increased frequency of degeneration in the cranial adjacent segment. Hypermobility and concomitant increased loads are discussed as a possible reason for segmental degeneration. We therefore examined the lumbar and segmental motion distribution in patients with LSTV with flexion-extension radiographs.MethodsA retrospective study of 51 patients with osteochondrosis L5/S1 with flexion and extension radiographs was performed. Of these, 17 patients had LSTV and were matched 1:1 for age and sex with patients without LSTV out of the collective of the remaining 34 patients. The lumbar and segmental range of motion (RoM) by segmental lordosis angle and the segmental wedge angle were determined. Normal distribution of parameters was observed by Kolmogorov-Smirnov-test. Parametric data were compared by paired T-test. Non-parametric data were compared by Wilcoxon-rank-sum-test. Correlations were observed using Spearman’s Rank correlation coefficient. A p-value <0.05 was stated as statistically significant.ResultsPatients with LSTV had mean age of 52.2±10.9, control group of 48.9±10.3. Both groups included 7 females and 10 males. Patients with LSTV presented with reduced RoM of the lumbar spine (LSTV 37.3°±19.2°, control 52.1°±20.5°, p = 0.065), however effects were statistically insignificant. LSTV significantly decreased segmental RoM in the transitional segment (LSTV 1.8°±2.7°, control 6.7°±6.0°, p = 0.003). Lumbar motion distribution differed significantly; while RoM was decreased in the transitional segment, (LSTV 5.7%, control 16.2%, p = 0.002), the distribution of lumbar motion to the cranial adjacent segment was increased (LSTV 30.7%, control 21.6%, p = 0.007).ConclusionPatients with LSTV show a reduced RoM in the transitional segment and a significantly increased motion distribution to the cranial adjacent segment in flexion-extension radiographs. The increased proportion of mobility in the cranial adjacent segment possibly explain the higher rates of degeneration within the segment.

Instability Missed by Flexion-Extension Radiographs Subsequently Identified by Alternate Imaging in L4-L5 Lumbar Degenerative Spondylolisthesis.

Cross-sectional preoperative and intraoperative imaging study of L4-L5 lumbar degenerative spondylolisthesis (LDS). To determine if alternate imaging modalities would identify LDS instability that did not meet the criteria for instability based on comparison of flexion and extension radiographs. Pain may limit full flexion and extension maneuvers and thereby lead to underreporting of true dynamic translation and angulation in LDS. Alternate imaging pairs may identify instability missed by flexion-extension. Consecutive patients scheduled for surgery for single-level L4-L5 LDS had preoperative standing radiographs in the lateral, flexion, and extension positions, supine computed tomography (CT) scans, and intraoperative fluoroscopic images in the supine and prone positions after anesthesia but before incision. Instability was defined as translation ≥3.5mm or angulation ≥11° between the following pairs of images: (1) flexion-extension; (2) CT-lateral; (3) lateral-intraoperative supine; (4) lateral-intraoperative prone; and (5) intraoperative supine-prone. Of 240 patients (mean age 68y, 54% women) 15 (6%) met the criteria for instability by flexion-extension, and 225 were classified as stable. Of these 225, another 84 patients (35% of total enrollment) were reclassified as unstable by comparison of CT-lateral images (21 patients) and by lateral-intraoperative images (63 patients). Nine of the 15 patients diagnosed with instability by flexion-extension had fusion (60%), and 68 of the 84 patients reclassified as unstable by other imaging pairs had fusion (81%) ( P =0.07). The 84 reclassified patients were more likely to undergo fusion compared with the 141 patients who persistently remained classified as stable (odds ratio=2.6, 95% CI: 1.4-4.9, P =0.004). Our study provides evidence that flexion and extension radiographs underreport the dynamic extent of LDS and therefore should not be solely relied upon to ascertain instability. These findings have implications for how instability should be established and the extent of surgery that is indicated.

Dynamic Radiographs Are Unreliable to Assess Arthrodesis Following Cervical Fusion: A Modeled Radiostereometric Analysis of Cervical Motion.

In vitro study. The purpose of the present study was to utilize an idealized cervical spine model to determine whether the parallax effect or changes in the position of the spine relative to the x-ray generator influence intervertebral motion parameters on dynamic cervical spine radiographs. The utility of flexion-extension radiographs in clinical practice remains in question due to poor reliability of the parameters utilized to measure motion. A cervical spine model with tantalum beads inserted into the tip of each spinous process was utilized to measure interspinous process distance (IPD) on plain radiographs. The model was then manipulated to alter the generator angle and generator distance, and the IPD was measured. The impact of individual and combined changes in these parameters on IPD was assessed. Multivariate analysis was performed to identify independent drivers of variability in IPD measurements. Isolated changes in the generator distance and generator angle and combined changes in these parameters led to significant changes in the measured IPD at each intervertebral level in neutral, flexion, and extension, which, in many instances, exceeded an absolute change of >1mm or >2mm. Multivariate analysis revealed that generator distance and generator angle are both independent factors impacting IPD measurements that have an additive effect. In an idealized cervical spine model, small clinically feasible changes in spine position relative to the x-ray generator produced substantial variability in IPD measurements, with absolute changes that often exceeded established cutoffs for determining the presence of pathologic motion across a fused segment. This study further reinforces that motion assessment on dynamic radiographs is not a reliable method for determining the presence of an arthrodesis unless these sources of variability can be consistently eliminated. 3.

Utility of Flexion-Extension Radiographs with Brackets and Magnetic Resonance Facet Fluid for the Assessment of Lumbar Instability in Degenerative Lumbar Spondylolisthesis

To propose a new standardized technique for evaluating lumbar stability in degenerative lumbar spondylolisthesis using lumbar lateral flexion-extension radiographs with brackets and magnetic resonance facet fluid. A retrospective analysis of 57 patients diagnosed with lumbar (L4-5) spondylolisthesis was performed. We analyzed lateral flexion-extension radiographs obtained with a bracket (LFEB) and without a bracket (LFE). Sagittal translation, segmental angulation, posterior opening, lumbar instability, and changes in lumbar lordosis were compared using functional radiographs. The mean width and maximum width of the facet fluid, mean facet joint length, and facet fluid index (FFI) of the 2 groups were compared using sagittal translation. The average value of sagittal translation was 1.68 ± 0.96mm in LFE and 3.07 ± 1.29mm in LFEB, and the difference was significant (P < 0.05). Segmental angulation, posterior opening, and changes in lumbar lordosis were significantly greater in LFEB than in LFE. The instability detection rate was 14.0% in LFE and 35.1% in LFEB. The FFI, maximum width, and mean width were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFEB. The FFI and maximum width of the facet fluid were significantly increased in the unstable lumbar spondylolisthesis group compared with the stable group in LFE. Lumbar lateral flexion-extension radiographs with brackets can standardize the operation process and provide sufficient hyperflexion and hyperextension images. The width of the facet fluid and FFI are significant factors in the evaluation of lumbar stability in patients with lumbar spondylolisthesis.

Radiographic analysis of dynamic lumbar motion during the five-repetition sit-to-stand test in degenerative lumbar spondylolisthesis

BackgroundTo investigate the mechanisms of low back pain triggered by the five-repetition sit-to-stand test (5R-STS test) in degenerative lumbar spondylolisthesis (DLS) from radiographic perspective, as well as to determine the most useful diagnostic modalities in the evaluation of segmental instability.MethodsWe retrospectively performed a study of 78 patients (23 men and 55 women) with symptomatic DLS at L4/5 in our institution between April 2020 and December 2021. Each patient was assessed by using the 5R-STS test and received a series of radiographs including the upright standing, normal sitting, standing flexion–extension radiographs, and supine sagittal MR images. Enrolled patients were divided into two groups based on the 5R-STS test score: severe group and mild group. Translational and angular motion was determined by comparing normal sitting radiograph (N) with upright standing radiograph (U) (Combined, NU), flexion/extension radiographs (FE) as well as normal sitting radiograph (N) with a supine sagittal MR image (sMR) (Combined, N-sMR).ResultsOverall, 78 patients were enrolled, and there were 31(39.7%) patients in group S and 47(60.3%) patients in group M, with an average age of 60.7 ± 8.4 years. The normal sitting radiograph demonstrated the maximum slip percentage (SP) and the highest kyphotic angle both in group S and group M. Compared with group M, group S revealed significantly higher SP in the normal sitting position (24.1 vs 19.6; p = 0.002). The lumbar slip angular in group S with a sitting position was significantly higher than that in group M (-5.2 vs -1.3; p < 0.001). All patients in group S had objective functional impairment (OFI) and 28 patients of them were diagnosed with lumbar instability by using the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) (Combined, N-sMR).ConclusionDLS patients with positive sign of the 5R-STS test is a distinct subgroup associated with lumbar instability. The modality of the combination of normal sitting radiograph (N) and supine sagittal MR image (sMR) had a significant advantage in terms of the ability to identify segmental instability.