Assessing accuracy of measurement methods for bony fusion assessment after anterior cervical discectomy.

BACKGROUND CONTEXT: Currently, there is no universally accepted method for assessing radiological fusion shortly after anterior cervical discectomy. Five-year follow-up radiological X-rays demonstrating solid fusion or absence of fusion provided a gold standard for comparison with various assessment methods. PURPOSE: Establishing the most accurate diagnostic test for earlier bony fusion assessment by comparing different cut-off values for the difference in interspinous distance and the change in Cobb angle on dynamic radiological images against the established gold standard. DESIGN: Post-hoc analysis from the NEtherlands Cervical Kinematics (NECK) trial (NTR1289). PATIENT SAMPLE: A total of 40 patients with 1 level herniated disc that underwent anterior discectomy between 2010 and 2014 returned for a 5-year follow-up X-ray. OUTCOME MEASURES: Radiological outcome was assessed quantitatively and qualitatively by fusion on radiographic images 5 years after surgery. METHODS: Radiological dynamic X-rays were reviewed for fusion at 5-year follow-up by a senior spine surgeon. At this timepoint, bony continuity was indisputable and served as gold standard. Cobb angles and interspinous distances on flexion-extension images were measured independently by 2 investigators. Optimum agreement between the gold standard and the 2 methods was assessed, evaluating varying cut-off values, considering sensitivity, specificity, and area under the curve (AUC). RESULTS: Dynamic radiographic assessments revealed fusion in 29 out of 40 patients (mean age: 49 years ± 8; 23 women). For Cobb angle (optimal cut-off: ≤3.0°), the AUC was 0.86 with 100% sensitivity and 72.7% specificity. For interspinous distance (optimal cut-off: ≤1.5 mm), the AUC was 0.89 with 96.6% sensitivity and 81.8% specificity. The highest AUC (0.91) was observed for combined cut-off values (Cobb angle ≤3.0° and interspinous distance ≤2.0 mm), yielding 100% sensitivity and 81.8% specificity. CONCLUSION: The combination of cut-off values ≤3.0° difference for Cobb angle and ≤2.0 mm difference for interspinous distance on lateral flexion-extension X-rays was assessed to be an accurate diagnostic criterion for fusion evaluation. This tool provides a practical and easy applicable method for assessing fusion during follow-up after anterior discectomy.

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

Background: To determine the factors in posterior ligamentous complex indicating lumbar instability in patients diagnosed with degenerative spondylolisthesis on conventional magnetic resonance imaging (MRI). Methods: 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. Results: 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. Conclusion: 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.

Neonatal head circumference to maternal mid-transverse pelvic distance ratio as a key anatomical predictor for dystocia: Retrospective case-control study.

OBJECTIVE: This study aimed to examine maternal and neonatal factors in cesarean deliveries due to dystocia, including cephalopelvic disproportion, latent-phase prolongation, and fetal malposition or malpresentation. Additionally, we sought to compare the differences between the dystocia subgroups. METHOD AND MATERIALS: This retrospective case-control study included women who delivered between January 2010 and June 2021 after 37 weeks of pregnancy and underwent abdominal-pelvic CT scans within 5 years before and after delivery. Neonatal factors were extracted from medical charts immediately after delivery. RESULTS: Among the 292 women studied, those with cesarean deliveries for dystocia were older (mean ± SD, 34.2 ± 4.27 vs. 32.2 ± 3.8, p-value = 0.002), had higher pre-pregnancy BMI (22.7 ± 3.67 vs. 21.4 ± 3.48, p-value = 0.012) and term-BMI (27.4 ± 3.72 vs. 25.9 ± 3.66, p-value = 0.010), shorter interspinous distance (ISD, the distance between ischial spine) (10.8 ± 0.76 vs. 11.2 ± 0.85 cm, p-value = 0.003), and longer head circumference (HC) (35 ± 1.47 vs. 34.4 ± 1.36 cm, p-value = 0.003) compared to those who had vaginal deliveries. Univariate logistic regression for dystocia revealed associations between HC/maternal height and HC/ISD ratios (OR, 2.02 [95% confidence interval, CI, 1.4 ~ 2.92], 12.13 [3.2 ~ 46.04], respectively). Multivariate logistic analysis indicated that maternal age, ISD, and HC were significant factors for dystocia (OR, 1.11 [95% CI, 1.01 ~ 1.21], 0.49 [0.26 ~ 0.91], 1.53 [1.07 ~ 2.19], respectively). The subgroup with latent-phase prolongation exhibited the lowest birthweight/term-BMI ratio (124 ± 18.8 vs. 113 ± 10.3 vs. 134 ± 19.1, p-value = 0.013). CONCLUSION: The HC/ISD ratio emerged as a crucial predictor of dystocia, suggesting that reducing term-BMI could potentially mitigate latent-phase prolongation. Further research assessing the maternal mid-pelvis during pregnancy and labor is warranted, along with efforts to reduce BMI during pregnancy.

Effect of Coronal Angulation of Sacral Vestibule S2 on Morphometric Analysis of Sacral Vestibule Using Plain Computed Tomography in North-West Indian Population.

BACKGROUND: The present study was aimed to study and develop in-depth understanding of the effect of the coronal angulation of sacral vestibule S2 on morphometry of sacral vestibule in north-west Indian population presenting to our institution, which will go a long way in planning to treat the posterior pelvic injuries with percutaneous screws, thereby reducing the morbidity associated with open fixation. METHODS: This study was conducted in the Department of Orthopaedics and Radiodiagnosis at Dr Rajendra Prasad Govt.Medical College, Kangra at Tanda over a period of one year. All the patients of the age > 18 years and above submitting for either abdominal, lower spinal or non-orthopedic pathology of pelvic region, presenting for computed tomography to the Department of Radiodiagnosis were included in the study. RESULTS: The coronal angulation of S2 vestibule ranged from 1° to 10° with a mean of 5.06° ± 2.77°. There was a weak relation between coronal angulation of S2 and age-groups 18-30 years (r = 0.105; P = 0.186), 31-40 years (r = 0.040; P = 0.715), 41-50 years (r = - 0.085; P = 0.330), 51-60 years (r = 0.119; P = 0.079), and > 60 years (r = - 0.166; P = 0.605). There was non-significant difference in coronal angulation of S2 (P = 0.913) between males and females. There was a weak relation between interspinus distance with coronal angulation of S2 (r = 0.069; P = 0.090). There was no relation between height with coronal angulation of S2 (r = 0.019; P = 0.631). CONCLUSION: The present study, the first of its kind in the north-western part of India arrived to help us anthropometric measurements of sacral vestibule, thereby, helping in development of local protocols for percutaneous fixation in sacral fracture.

Another diagnostic tool in thoracolumbar posterior ligament complex injury: interspinous distance ratio.

PURPOSE: The increased interspinous distance ratio (ISDR) at the fracture site in plain X-ray is useful as an indicator of injury of the posterior ligament complex in thoracolumbar fractures. METHODS: 154 patients of thoracolumbar junctional fracture (T12, L1, L2) were subjects for this study. The sensitivity, specificity, accuracy of MRI was measured by comparing the surgery findings for the two analysis groups: one in which indeterminate cases were included in the intact group and another in which the indeterminate cases were included in the ruptured group. Sensitivity, specificity, accuracy of ISDR (measured in lateral decubitus X-ray) were measured after dividing patients into 3 groups (110, 120, 130 % increased). RESULTS: MRI's sensitivity, specificity and accuracy were 70.8, 100, and 80.5 %, respectively, when the indeterminate was assumed to have intact PLC. After assuming the indeterminate to have ruptured PLC, sensitivity, specificity and accuracy were 99.1, 52.4, and 85.7 %, respectively. In 53 cases with indeterminate MRI reading, sensitivity, specificity and accuracy were 81.2, 76.2, and 79.2 % %, respectively. CONCLUSION: In this study, in cases where it was difficult to make a diagnosis of the injury in the posterior ligament complex, based on the interspinous distance ratio (ISDR) of 120 % measured in plain X-ray in a lateral decubitus position, the sensitivity was 81.3 %, the specificity was 76.2 %, and the accuracy was 79.2 %. Therefore, measuring the ISDR will be helpful in determining whether surgical treatment is required in patients with thoracolumbar injury.

Prediction of posterior ligamentous complex injury in thoracolumbar fractures using non-MRI imaging techniques.

PURPOSE: We aimed to formulate a radiological index based on plain radiographs and computer tomography (CT) to reliably detect posterior ligamentous complex (PLC) injury without need for MRI. METHODS: Sixty out of 148 consecutive thoracolumbar fractures with doubtful PLC were assessed with MRI, CT and radiographs. PLC injury was assessed with the following radiological parameters: superior-inferior end plate angle (SIEA), vertebral body height (BH), local kyphosis (LK), inter-spinous distance (ISD) and inter-pedicular distance (IPD) and correlated with MRI findings of PLC injury. Statistical analysis was performed to identify the predictive values for the parameters to identify PLC damage. RESULTS: MRI identified PLC injury in 25/60 cases. The ISD and LK were found to be significant predictors of PLC injury. On radiographs the mean LK with PLC damage was 25.86° compared to 21.02° with an intact PLC (p = 0.006). The ISD difference was 6.70 mm in cases with PLC damage compared to 2.86 mm with an intact PLC (p = 0.011). In CT images, the mean LK with PLC damage was 22.96° compared to 18.44° with an intact PLC ( p = 0.019). The ISD difference was 3.10 mm with PLC damage compared to 1.62 mm without PLC damage (p = 0.005). CONCLUSIONS: On plain radiographs the presence of LK greater than 20 °(CI 64-95) and ISD difference greater than 2 mm (CI 70-97) can predict PLC injury. These guidelines may be utilised in the emergency room especially when the associated cost, availability and time delay in performing MRI are a concern.

A morphometric study of the lumbar interspinous space in 100 stanford university medical center patients.

OBJECTIVE: With the increased use of interspinous spacers in the treatment of lumbar stenosis, knowledge of the geometry of the interspinous space is important. To prevent dislodgment of an interspinous spacer, the accurate depth and width of the interspinous space needs to be established to facilitate the best intraoperative selection of correct spacer size. METHODS: To determine the depth and width of the interspinous space, two methods are available which utilize plain film and magnetic resonance imaging (MRI). Data analysis of the interspinous depth and width was undertaken in 100 patients. RESULTS: The standard deviations were variable, since skin thickness (zone 1) was altered by sex and age. The difference in the zone 1 distance between adjacent interspinous processes varied according to gender (p<0.05), but was not influenced by age [p=0.32 by analysis of variance between groups (ANOVA)]. Zone 2, the supraspinous, and zone 3, the interspinous ligament depths, comprise the operative working area during insertion of an interspinous spacer. There were no differences with regard to gender or age (p>0.05). For zones 6 and 7, the interspinous distances at the narrowest and widest points, respectively, were found to decrease with the aging process, but the decrease was not statistically significant. There were no differences with regard to gender (p>0.05). CONCLUSION: This study provides additional information on the interspinous space. This statistical data are valuable for use in the design of interspinous spacers.