Diagnostic Value of Various Morphological Features of Horizontal and Vertical Laminar Fractures for Posterior Ligamentous Complex Injury of the Thoracolumbar Spine as Defined by Magnetic Resonance Imaging.

OBJECTIVE: To determine diagnostic value of morphological features of horizontal laminar fracture (HLF) and vertical laminar fracture (VLF) for diagnosis of posterior ligamentous complex (PLC) injury. METHODS: This retrospective review comprised 271 consecutive patients with acute thoracolumbar fractures presenting to a Level 1 trauma center between January 2014 and January 2021. Two reviewers evaluated computed tomography and magnetic resonance imaging. VLFs were subclassified based on length and depth of lamina involved, as follows: type 1, full-length complete; type 2, full-length incomplete; type 3, partial-length complete or incomplete. HLFs were subclassified as follows: bilateral versus unilateral, displaced >2 mm versus nondisplaced, and lamina-only versus laminar and pedicle. We examined the diagnostic accuracy and the univariate and multivariate associations of laminar fracture subtypes with PLC injury as defined by black stripe discontinuity. RESULTS: Bilateral HLFs, laminar and pedicle fractures, displaced HLFs, and type 1 VLFs yielded a high positive predictive value for PLC injury (95%, 91%, 100%, and 86%, respectively). Type 2 and 3 VLFs did not show significant univariate associations with PLC injury. Bilateral HLFs, laminar and pedicle fractures, and displaced HLFs showed independent associations with PLC injury (adjusted odds ratio = 13.6, 8.4, 6, and 10.3, respectively; P < 0.002). Type 1 VLFs did not show a significant association with PLC (adjusted odds ratio = 10.3; P = 0.06). CONCLUSIONS: Bilateral HLFs, laminar and pedicle fractures, and displaced HLFs, but not any VLF subtypes, were independently associated with PLC injury. These findings may improve the reliability of PLC assessment by computed tomography.

Analysis of the Combined Computed Tomography Findings Improves the Accuracy of Computed Tomography for Detecting Posterior Ligamentous Complex Injury of the Thoracolumbar Spine as Defined by Magnetic Resonance Imaging.

OBJECTIVE: To determine the diagnostic accuracy of combined computed tomography (CT) findings for detecting posterior ligamentous complex (PLC) injury in thoracolumbar fractures using magnetic resonance imaging as a reference. METHODS: A retrospective review of 263 consecutive patients with thoracolumbar fractures who underwent CT and magnetic resonance imaging within 10 days of injury. Two reviewers evaluated CT for the following findings: facet joint malalignment, facet joint widening, horizontal laminar fracture, spinous process fracture, and interspinous widening. We examined the independent association of CT findings with PLC injury before combining the CT findings to calculate the diagnostic accuracy: sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), and positive and negative likelihood ratios. PLC injury was defined by black stripe discontinuity caused by supraspinous or ligamentum flavum rupture. RESULTS: Facet joint malalignment, spinous process fracture, horizontal laminar fracture, and interspinous widening were independently associated with PLC injury (adjusted odds ratio range, 4.4e17.4). A single positive CT finding yielded a PPV of 31% and NPV of 66% for PLC injury. Two or more CT findings yielded a PPV of 91% for PLC injury. A negative CT for all the 4 CT sings had a 94% NPV for PLC injury. CONCLUSIONS: Two or more CT findings provided the best combination to confirm PLC injury; thus, this combination could be used as a criterion for injured PLC. A single CT finding lacks sufficient predictive value to confirm or rule out PLC injury. A negative CT for the 4 CT findings provided the highest sensitivity for PLC injuries.

Espondiloartrosis cervical e hipertrofia del ligamento amarillo / Cervical Spondyloarthrosis and Hypertrophy of the Yellow Ligament

RESUMEN Introducción: La espondiloartrosis cervical es una enfermedad articular crónica degenerativa, es la afección articular más frecuentemente observada en la población madura y una de las principales causas de discapacidad en todo el mundo, por lo que es importante el diagnóstico y tratamiento en las fases tempranas. Objetivo: Informar un caso clínico representativo de espondiloartrosis cervical e hipertrofia del ligamento amarillo. Presentación del caso: Paciente femenina de 49 años que seis años atrás sufrió una caída, y se golpeó el occipucio contra la pared, lo que le provocó pérdida transitoria del conocimiento y dolor en la región cervical; tres años después comenzó con limitación a los movimientos laterales del cuello, malestar y dolor sordo, referido a la nuca y al cuello. Conclusiones: El diagnóstico de espondiloartrosis cervical e hipertrofia del ligamento amarillo representa un desafío clínico, por lo poco común de la enfermedad a esta edad. El caso presentado es una paciente con alteraciones estructuradas en el esqueleto axial y gran repercusión anatómica y funcional debido a un relativo diagnóstico tardío, con evolución insatisfactoria. Por tanto, conviene conocer la enfermedad para realizar una detección precoz y ofrecer mejor atención terapéutica(AU)

ABSTRACT Introduction: Cervical spondyloarthrosis is a chronic degenerative joint disease, it is the most frequent joint condition in the mature population and one of the main causes of disability throughout the world, so diagnosis and treatment in the early stages are important. Objective: To report a representative clinical case of cervical spondyloarthrosis and hypertrophy of the yellow ligament. Case presentation: A 49-year-old female patient suffered a fall six years ago, hitting her occiput against the wall, causing her temporary loss of consciousness and pain in the cervical region. Three years later, she began with limitation of lateral neck movements, discomfort and dull pain, referred to the nape and neck. Conclusion: The diagnosis of cervical spondyloarthrosis and hypertrophy of the yellow ligament represents a clinical challenge, due to the rare nature of the disease at this age. The case reported is a patient with structured alterations in the axial skeleton and great anatomical and functional repercussions due to a relatively late diagnosis, with unsatisfactory evolution. Therefore, it is convenient to know the disease in order to early detect it and to offer better therapeutic care(AU)

Does the novel lateral trauma position cause more motion in an unstable cervical spine injury than the logroll maneuver?

OBJECTIVE: Prehospital personnel who lack advanced airway management training must rely on basic techniques when transporting unconscious trauma patients. The supine position is associated with a loss of airway patency when compared to lateral recumbent positions. Thus, an inherent conflict exists between securing an open airway using the recovery position and maintaining spinal immobilization in the supine position. The lateral trauma position is a novel technique that aims to combine airway management with spinal precautions. The objective of this study was to compare the spinal motion allowed by the novel lateral trauma position and the well-established log-roll maneuver. METHODS: Using a full-body cadaver model with an induced globally unstable cervical spine (C5-C6) lesion, we investigated the mean range of motion (ROM) produced at the site of the injury in six dimensions by performing the two maneuvers using an electromagnetic tracking device. RESULTS: Compared to the log-roll maneuver, the lateral trauma position caused similar mean ROM in five of the six dimensions. Only medial/lateral linear motion was significantly greater in the lateral trauma position (1.4mm (95% confidence interval [CI] 0.4, 2.4mm)). CONCLUSIONS: In this cadaver study, the novel lateral trauma position and the well-established log-roll maneuver resulted in comparable amounts of motion in an unstable cervical spine injury model. We suggest that the lateral trauma position may be considered for unconscious non-intubated trauma patients.

Airway management in a patient with nuchal, interspinous, and flavum ligament rupture by a sickle: a case report.

BACKGROUND: Penetrating neck injury is an important trauma subset but is relatively rare, especially when involving the posterior cervical column. Rupture of the neck restraints, including the interspinous and flavum ligaments, can create serious cervical instability that requires special consideration when managing the airway. However, no detailed information regarding airway management in patients with profound posterior neck muscle laceration and direct cervical ligament disruption by an edged weapon is yet available in the literature. CASE PRESENTATION: A 63-year-old Japanese man attempted to cut off his head using a sickle after drinking a copious amount of alcohol. On admission, his posterior vertebral column was grossly exposed and the lacerated tissues were actively bleeding, resulting in severe hypovolemic shock. We used a rapid-sequence intubation technique with direct laryngoscopy while manual in-line stabilization of his head and neck was maintained by several people. Surgical exploration revealed nuchal, interspinous, and flavum ligament rupture between his fourth and fifth cervical vertebrae, but no injury to the great vessels was present. The major source of bleeding was a site of oozing from his trapezius and splenius muscles. After surgical hemostasis, wound repair, and subsequent intensive care, our patient was discharged home without any neurological sequelae. CONCLUSIONS: Deficits of the neck restraints can cause cervical spine subluxation and dislocation secondary to neck movement. Thus, the key to successful airway management in such a scenario is minimization of neck movement to prevent further neurological impairment. We successfully managed an airway using a conventional but trusted endotracheal intubation strategy in a patient with multiple traumas and a suspected spinal cord injury. This case also illustrates that, even when great vessel injury is absent, severe hypovolemic shock may occur after profound neck muscle laceration, requiring immediate surgical intervention.

Efficacy of MRI for assessment of spinal trauma: correlation with intraoperative findings.

STUDY DESIGN: Observational diagnostic study on consecutive patients. OBJECTIVE: To assess the efficacy of magnetic resonance imaging (MRI) for detecting spinal soft tissue injury after acute trauma using intraoperative findings as a reference standard. SUMMARY OF BACKGROUND DATA: Recognizing injuries to spinal soft tissue structures is critical for proper decision making and management for blunt trauma victims. Although MRI is considered the gold standard for imaging of soft tissues, its ability to identify specific components of soft tissue damage in acute spine trauma patients is poorly documented and controversial. METHODS: Intraoperative findings were recorded for 21 acute spinal trauma patients (study group) and 14 nontraumatic spinal surgery patients (control group). Preoperative MRI's were evaluated randomly and blindly by 2 neuroradiologists. MRI and intraoperative findings were compared. By using the intraoperative findings as the reference standard, sensitivity, specificity, positive and negative predictive values of MRI in detecting spinal soft tissue injury were determined. RESULTS: MRI was 100% sensitive and specific in detecting injury to the anterior longitudinal ligament. MRI was moderately sensitive (80%) but highly specific (100%) for injury to the posterior longitudinal ligament. In contrast, MRI was highly sensitive but less specific in detecting injury to paraspinal muscles (100%, 77%), intervertebral disk (100%, 71%), and interspinous ligament (100%, 64%). MRI was moderately sensitive and specific in detecting ligamentum flavum injury (80% and 86.7%) but poorly sensitive for facet capsule injury (62.5%). CONCLUSIONS: MRI demonstrated high sensitivity for spinal soft tissue injuries. However, MRI showed a definite trend to overestimate interspinous ligament, intervertebral disk, and paraspinal muscle injuries. On the basis of these results, we would consider MRI to be a useful tool for spine clearance after trauma. Conversely, caution should be applied when using MRI for operative decision making due to its less predictable specificity.

Relationships between posterior ligamentous complex injury and radiographic parameters in patients with thoracolumbar burst fractures.

INTRODUCTION: The purpose of this study was to determine whether radiographic findings associated with thoracolumbar burst fractures could also indicate the presence of posterior ligamentous complex (PLC) injuries, which were identified through short-tau inversion-recovery (STIR)-weighted MRI. PATIENTS AND METHOD: Sixty-four patients were surgically treated for thoracolumbar burst fractures between April 2007 and February 2014 at our institution. Twenty-four patients were excluded from this study because of the lack of STIR-weighted MRIs, and therefore 40 patients were included in this study. The patients were divided into two groups based upon the integrity of the PLC, which was evaluated using STIR-weighted MRI: a P group with a PLC injury and a C group without such injury. The following radiographic parameters were evaluated: loss of vertebral body height (LOVBH), local kyphosis (LK), vertebral body translation, canal compromise (sagittal transverse ratio, STR), interlaminar distance (ISD), supraspinous distance (SSD) and interspinous distance (ISD). Frankel scale score and total severity score (load sharing and thoracolumbar injury classification systems, respectively) were also evaluated. RESULTS: Preoperative STIR-weighted MRI showed that 25 patients had a PLC injury (P group: 15 men and 10 women), and 15 patients did not have a PLC injury (C group: 8 men and 7 women). More patients in the P group had an LK>20°: 14 patients in the P group and 1 patient in the C group (p<0.01). The % SSD differed between the P and C groups (118.8%±53.4% and 88.0%±24.3%, respectively; p<0.05). Multivariate logistic analysis showed that an LK>20° was a risk factor for PLC injury in patients with thoracolumbar burst fractures (odds ratio, 55.5 [95% confidence interval, 1.30-2360.1]; p<0.05). CONCLUSIONS: These results demonstrate that while LOVBH, vertebral body translation, and canal compromise do not correlate significantly with the presence of a PLC injury in patients with thoracolumbar fractures, an LK>20° and increased % SSD are associated with a PLC injury.

Failure properties and damage of cervical spine ligaments, experiments and modeling.

Cervical spine ligaments have an important role in providing spinal cord stability and restricting excessive movements. Therefore, it is of great importance to study the mechanical properties and model the response of these ligaments. The aim of this study is to characterize the aging effects on the failure properties and model the damage of three cervical spine ligaments: the anterior and the posterior longitudinal ligament and the ligamentum flavum. A total of 46 samples of human cadaveric ligaments removed within 24-48 h after death have been tested. Uniaxial tension tests along the fiber direction were performed in physiological conditions. The results showed that aging decreased the failure properties of all three ligaments (failure load, failure elongation). Furthermore, the reported nonlinear response of cervical ligaments has been modeled with a combination of the previously reported hyperelastic and damage model. The model predicted a nonlinear response and damage region. The model fittings are in agreement with the experimental data and the quality of agreement is represented with the values of the coefficient of determination close to 1.

MRI study of post-traumatic incompetence of posterior ligamentous complex: importance of the supraspinous ligament. Prospective study of 74 traumatic fractures.

PURPOSE: Posterior ligamentous complex (PLC) components have an orderly sequence of rupture. However, it is still unclear how many structures have to be damaged to consider it disrupted. We aim to establish imaging criteria, which can define the complex as competent or incompetent. METHODS: Prospective study of 74 consecutive vertebral acute traumatic fractures, using X-rays and MRI scan (FS-T2-w/STIR sequences). We analyzed the association between MRI signal (intact, edema, disruption) of each PLC component-facet capsules (FC), interspinous ligaments (ISL), supraspinous ligaments (SSL) and ligamentum flavum (LF)-and the variables: AO/TLICS classification, treatment, surgical findings, interspinous diastasis index (IDI), local kyphosis (LVK) and ISS (TLICS) score. χ2 test and U Mann-Whitney were used for statistics. RESULTS: MR images of ISL edema correlated surgically with intact ligaments or laxity, and were associated with 87.5% of facet distraction, LVK: 11.6º, IDI: 1.2. Images of ISL, SSL or LF disruptions showed in all cases ruptures under surgical examination. Images of SSL disruption associated with LVK: 14.5º, IDI: 1.8. Images of ISL disruption associated with SSL/LF rupture, LVK: 16º, and IDI: 2; while LF disruption showed LVK: 18º, IDI: 1.9. When comparing "competent PLC" (images of facet distraction and ISL edema) with "incompetent PLC" (images of SSL disruption ± ISL or LF disruption) the latest showed more severe scores in every variable (p < 0.001), except neurologic status. CONCLUSION: Following PLC rupture sequence, ISL edema with facet distraction seems not to be enough to define a posterior tension band incompetence. It is the further step of SSL rupture what gives the key to PLC incompetence.

Acoustic emission signals can discriminate between compressive bone fractures and tensile ligament injuries in the spine during dynamic loading.

Acoustic emission (AE) sensors are a reliable tool in detecting fracture; however they have not been used to differentiate between compressive osseous and tensile ligamentous failures in the spine. This study evaluated the effectiveness of AE data in detecting the time of injury of ligamentum flavum (LF) and vertebral body (VB) specimens tested in tension and compression, respectively, and in differentiating between these failures. AE signals were collected while LF (n=7) and VB (n=7) specimens from human cadavers were tested in tension and compression (0.4m/s), respectively. Times of injury (time of peak AE amplitude) were compared to those using traditional methods (VB: time of peak force, LF: visual evidence in high speed video). Peak AE signal amplitudes and frequencies (using Fourier and wavelet transformations) for the LF and VB specimens were compared. In each group, six specimens failed (VB, fracture; LF, periosteal stripping or attenuation) and one did not. Time of injury using AE signals for VB and LF specimens produced average absolute differences to traditional methods of 0.7 (SD=0.2) ms and 2.4 (SD=1.5) ms (representing 14% and 20% of the average loading time), respectively. AE signals from VB fractures had higher amplitudes and frequencies than those from LF failures (average peak amplitude 87.7 (SD=6.9) dB vs. 71.8 (SD=9.8)dB for the inferior sensor, p<0.05; median characteristic frequency from the inferior sensor 97 (interquartile range, IQR, 41) kHz vs. 31 (IQR 2) kHz, p<0.05). These findings demonstrate that AE signals could be used to delineate complex failures of the spine.

Correlation of posterior ligamentous complex injury and neurological injury to loss of vertebral body height, kyphosis, and canal compromise.

STUDY DESIGN: Retrospective, case-control study. OBJECTIVE: The purpose of this study was to determine if thoracolumbar vertebral body collapse, translation, or canal compromise (CC) is associated with injury to the posterior ligamentous complex (PLC) or neurological elements. SUMMARY OF BACKGROUND DATA: Radiographical parameters, including loss of vertebral body height (LOVBH), vertebral body translation, local kyphosis (LK), and CC, are often used as indicators of spinal instability. The hypothesis of this study was that LOVBH greater than 50%, LK greater than 20°, translation greater than 3.5 mm, or CC greater than 50% is associated with ligamentous and neurological injury. METHODS: Retrospective review of prospectively collected spinal cord injury database was performed. Inclusion criteria include consecutive patients with thoracolumbar burst fractures. Exclusion criteria include flexion-distraction injuries and pathological fractures. Computed tomographic scan measurements of the spine were performed by 2 experienced spine surgeons blinded to magnetic resonance imaging results. On magnetic resonance imaging, the supraspinous ligament, interspinous ligament, ligamentum flavum, facet joints, and disc were graded as intact, indeterminate, or disrupted. American Spinal Injury Association (ASIA) score and Frankel Scale score were recorded. Spearman correlation coefficients were calculated to evaluate relationships between vertebral body measurements, ligamentous injury, and neurological injury. RESULTS: Forty-six patients were included in the study. Ten patients had kyphosis greater than 20°, 1 patient had kyphosis greater than 30°, and 9 patients had LOVBH greater than 50%. There were 34 patients with vertebral body translation greater than 3.5 mm and 15 patients with CC greater than 50%. Sixteen patients had ligamentous injury. There was a significant correlation between subjacent segment translation greater than 3.5 mm and ligamentous injury (R = 0.323, P = 0.029) and ASIA motor score (R = -0.379, P = 0.009). There was no significant correlation between ligamentous injury or neurological injury and the following threshold parameters: LOVBH greater than 50%, vertebral body kyphosis greater than 20°, caudal or cephalad interspinous widening greater than 7 mm, CC greater than 50%, and sagittal transverse ratio less than 0.48. CONCLUSION: The results of this study indicate that LOVBH greater than 50% and LK greater than 20° are not predictive of PLC injury in thoracolumbar burst fractures. Translation greater than 3.5 mm was associated with PLC injury. The PLC and neural elements should be directly assessed with magnetic resonance imaging if there is clinical concern.

Diagnostic abilities of magnetic resonance imaging in traumatic injury to the posterior ligamentous complex: the effect of years in training.

BACKGROUND CONTEXT: The integrity of the posterior ligamentous complex (PLC) has been proposed to be an integral aspect in the treatment algorithm for spinal trauma. Magnetic resonance imaging (MRI) has been reported as the ideal tool to determine the integrity of the PLC. The ability to assess disruption of the PLC by reviewers of differing levels of training has not been described. In addition, the MRI sequence most suggestive of injury for each component of the PLC has not been clearly determined. PURPOSE: This study was designed to determine the ability of reviewers with differing levels of training (fellowship-trained spine surgeon, fellowship-trained musculoskeletal radiologist, senior orthopedic surgery resident, and junior orthopedic surgery resident) to accurately interpret the results of MRI. The secondary purpose was to evaluate the MRI sequence that was most indicative of injury to the components of the PLC. STUDY DESIGN: This is a prospective radiological study comparing reviewers of MRI to determine integrity of the PLC components using intraoperative notation as the gold standard for integrity. PATIENT SAMPLE: Forty-five consecutive spinal trauma patients who underwent operative fixation after obtaining MRI. OUTCOME MEASURES: No patient outcome measures were used. METHODS: The sensitivity, specificity, and accuracy for each MRI reviewer in regard to MRI integrity were compared with the gold standard of intraoperative observation. In addition, the MRI sequence most suggestive of integrity of the PLC was noted by each reviewer for each component of the PLC. RESULTS: Forty-five patients (29 men and 16 women) with traumatic spine injuries were enrolled in the study. The sensitivity and accuracy of the surgeon were 0.83 (0.66, 0.92) and 0.81 (0.70, 0.88), respectively. The sensitivity and accuracy of the attending spine surgeon were not statistically significantly different from the other reviewers (p value=.2317 and .2582). However, the specificity of the surgeon was statistically significantly higher than that of the other reviewers (p=.0043). In the cervical, thoracic, and lumbar spine, the reviewers reached a 93% agreement that the sagittal short-tau inversion recovery (STIR) sequences were most helpful in visualizing injury to the supraspinous ligament (SSL), interspinous ligament (ISL), ligamentum flavum (LF), and the cervical facet capsules. The reviewers attained a 95% agreement that visualization of injury to the lumbar facet capsules is most optimal in the T2 axial sequences. CONCLUSIONS: The interpretation of traumatic MRI is very sensitive and accurate regardless of years of training of the observer. The attending-level spine surgeon was statistically more specific in the evaluation of injury MRIs. The fluid-weighted STIR sagittal sequences are most useful in determining injury to the SSL, ISL, LF, and cervical facets capsules. Lumbar facet capsules are best evaluated with axial T2 MRI. The evaluation of the PLC on MRI can be accurately and efficiently interpreted by physicians at multiple levels of training, thus providing a key imaging modality in determining stability and need for stabilization.

Injury of the posterior ligamentous complex of the thoracolumbar spine: a prospective evaluation of the diagnostic accuracy of magnetic resonance imaging.

STUDY DESIGN: Prospective diagnostic imaging study. OBJECTIVE: To determine the accuracy of magnetic resonance imaging (MRI) in diagnosing injury of the posterior ligamentous complex (PLC) in patients with thoracolumbar trauma. SUMMARY OF BACKGROUND DATA: Treatment decisions in thoracolumbar injury patients are currently based on the status of the PLC. It is, therefore, important to understand the accuracy of MRI in diagnosing varying degrees of PLC injury. Prior studies report that MRI is up to 100% sensitive for diagnosing PCL injury. METHODS: Patients with an acute injury from T1 to L3 who required posterior surgery were prospectively studied. A musculoskeletal radiologist, based on the preoperative MRI findings, characterized each of the 6 components of the PLC as intact, incompletely disrupted, or disrupted. During the surgical procedure, the surgeon identified each component of the PLC as intact, incompletely disrupted, or disrupted. The radiologist's interpretation and surgical findings were compared. RESULTS: Forty-two patients with 62 levels of injury were studied. There were 33 males (78.6%) and 9 females (21.4%), and the average age was 35.7 years. According to the kappa score, there was a moderate level of agreement between the radiologist's interpretation and the intraoperative findings for all PLC components except the thoracolumbar fascia, for which there was slight agreement. The sensitivity for the various PLC components ranged from 79% (left facet capsule) to 90% (interspinous ligament). The specificity ranged from 53% (thoracolumbar fascia) to 65% (ligamentum flavum). There was less agreement between the radiologist and surgeon for the patients with less severe neurologic compromise, i.e., those patients with an AIS grade of either D or E. CONCLUSION: The sensitivity and specificity of MRI for diagnosing injury of the PLC are lower than previously reported in the literature. The integrity of the PLC as determined by MRI should not be used in isolation to determine treatment.

Atlantal fracture with transverse ligament disruption in a child. Case report.

Even though fractures in children with immature spines occur predominantly in the upper cervical spine, isolated C-1 fractures are relatively rare. The fractures in almost all cases reported to date were considered stable due to the presence of the intact transverse ligament. The authors report the case of a young child who sustained a Jefferson fracture and in whom MR imaging revealed disruption of the transverse ligament. Although surgical treatment has been suggested as the treatment of choice for children with unstable atlantoaxial injuries, external immobilization alone allowed a full recovery in the patient with no evidence of instability at follow-up.

Interrater reliability of identifying indicators of posterior ligamentous complex disruption when plain films are indeterminate in thoracolumbar injuries.

BACKGROUND: The Spine Trauma Study Group (STSG) has proposed a novel thoracolumbar injury classification system and score (TLICS) in an attempt to define traumatic spinal injuries and direct appropriate management schemes objectively. The TLICS assigns specific point values based on three variables to generate a final severity score that guides potential treatment options. Within this algorithm, significant emphasis has been placed on posterior ligamentous complex (PLC) integrity. The purpose of this study was to determine the interrater reliability of indicators surgeons use when assessing PLC disruption on imaging studies, including computed tomography (CT) and magnetic resonance imaging (MRI). METHODS: Orthopedic surgeons and neurosurgeons retrospectively reviewed a series of thoracolumbar injury case studies. Thirteen case studies, including images, were distributed to STSG members for individual, independent evaluation of the following three criteria: (1) diastasis of the facet joints on CT; (2) posterior edema-like signal in the region of PLC components on sagittal T2-weighted fat saturation (FAT SAT) MRI; and (3) disrupted PLC components on sagittal T1-weighted MRI. Interrater agreement on the presence or absence of each of the three criteria in each of the 13 cases was assessed. RESULTS: Absolute interrater percent agreement on diastasis of the facet joints on CT and posterior edema-like signal in the region of PLC components on sagittal T2-weighted FAT SAT MRI was similar (agreement 70.5%). Interrater agreement on disrupted PLC components on sagittal T1-weighted MRI was 48.9%. Facet joint diastasis on CT was the most reliable indicator of PLC disruption as assessed by both Cohen's kappa (kappa = 0.395) and intraclass correlation coefficient (ICC 0.430). CONCLUSIONS: The interrater reliability of assessing diastasis of the facet joints on CT had fair to moderate agreement. The reliability of assessing the posterior edema-like signal in the region of PLC components was lower but also fair, whereas the reliability of identifying disrupted PLC components was poor.

[Unilateral lumbosacral dislocation]. / Unilaterale lumbosakrale Dislokation.

The authors present a very uncommon case of unilateral lumbosacral dislocation. Twenty two similar cases have been published in the literature so far. Most of them occurred due to the flexion mechanism of injury, in our case the injury was caused by a combination of hyperextension and subsequent flexion with rotation. This rare injury can create diagnostic dilemma and in relation to complexity of soft tissue lesion we propose early circumferential instrumented fusion of lumbosacral region.

Assessment of injury to the thoracolumbar posterior ligamentous complex in the setting of normal-appearing plain radiography.

BACKGROUND CONTEXT: The posterior ligamentous complex (PLC) is thought to contribute significantly to the stability of thoracolumbar spine. Obvious translation or dislocation of an interspace clearly denotes injury to the PLC. A recent survey of the Spine Trauma Study Group indicated that plain radiographic findings, if present, are most helpful in determining PLC injury. However, confusion exists when plain radiography shows injury to the anterior spinal column without significant kyphosis or widening of the posterior interspinous space. PURPOSE: The objective of this study is to identify imaging parameters that may suggest a disruption of the posterior ligamentous complex of the thoracolumbar spine in the setting of normal-appearing plain radiographs. This study was performed, in part, as a pilot study to determine critical imaging parameters to be included in a future prospective, randomized, multicenter study. STUDY DESIGN/SETTING: Survey analysis of the Spine Trauma Study Group. PATIENT SAMPLE: None. OUTCOME MEASURES: Compilation and statistical analysis of survey results. METHODS: Based on a systematic review of the English literature from 1949 to present, we identified a series of traits not found on plain X-rays that were consistent with PLC injury. This included five imaging findings on either computed tomography (CT) scans or magnetic resonance imaging (MRI) and several physical examination features. These items were placed on a survey and sent to the members of the Spine Trauma Study Group. They were asked to rank the items from most important to least important in representing an injury to the PLC in the setting of normal-appearing plain radiographs. RESULTS: Thirty-three of 47 surveys were returned for final analysis. Thirty-nine percent (13/33) of the members ranked "disrupted PLC components (i.e., interspinous ligament, supraspinous ligament, ligamentum flavum) on T1 sagittal MRI" as the most important factor in determining disruption of PLC. When analyzed with a point-weighted system, "diastasis of the facet joints on CT" received the most points, indicating that this category was ranked high by the majority of the members of the group. The members were also given freedom to add other criteria that they believed were important in determining PLC integrity in the setting of normal-appearing plain radiograph. Of the other criteria suggested, one included a physical finding and the other a variant of MR sequencing. CONCLUSIONS: In a setting of normal-appearing plain radiographs, PLC injury as displayed on T1-weighted MRI and diastasis of the facet joints on CT scan seem to be the most popular determinants of probable PLC injury among members of the Spine Trauma Study Group. Between MRI and CT scan, most members feel that various characteristics on MRI studies were more helpful.

Correlation of MR imaging findings with intraoperative findings after cervical spine trauma.

BACKGROUND AND PURPOSE: There are limited data correlating MR imaging and anatomic findings of ligamentous injury in cervical spine trauma. This study compares acute MR imaging with surgical observations of disk/ligamentous injury after blunt cervical trauma. MATERIALS AND METHODS: Consecutive patients with acute cervical spine trauma who underwent preoperative MR imaging and surgery from 1998 to 2001 were identified. MR imaging was obtained within 48 hours of injury for most patients. All scans included sagittal T1, T2 fat-saturated, and short tau inversion recovery sequences. At surgery, extent of injury at the operated level was recorded on a standardized form for either anterior or posterior structures or both depending upon the operative approach. MR examinations were separately evaluated by 2 readers blinded to the intraoperative findings. Radiologic and surgical findings were then correlated. RESULTS: Of 31 patients, an anterior surgical approach was chosen in 17 patients and a posterior approach in 13 patients. In one patient anterior and posterior approaches were utilized. Seventy-one percent of patients had spinal cord injury on MR imaging. MR imaging was highly sensitive for injury to disk (93%), posterior longitudinal ligament (93%), and interspinous soft tissues (100%), but it was less sensitive for injury to the anterior longitudinal ligament (71%) and ligamentum flavum (67%). For most ligamentous structures, there was limited agreement between specific MR imaging findings and injury at surgery. CONCLUSION: In acute cervical spine trauma, MR imaging has moderate to high sensitivity for injury to specific ligamentous structures but limited agreement between specific MR imaging findings and injury at surgery. MR imaging may overestimate the extent of disruptive injury when compared with intraoperative findings, with potential clinical consequences.

Three-column ligamentous extension injury of the thoracic spine: a case report and review of the literature.

STUDY DESIGN: This is a report of a patient with a rare unstable 3-column ligamentous injury of the thoracic spine. OBJECTIVE: To illustrate a rare unstable thoracic spine injury that required internal fixation despite its potentially benign clinical and radiologic presentation. SUMMARY OF BACKGROUND DATA: Extension injury of the thoracolumbar spine is uncommon. Although there have been several reports of hyperextension injuries in the thoracolumbar spine, the radiologic findings of the present case was different from those in the previously reported cases. METHODS: The clinical findings, roentgenographic appearance, treatment, were presented and the mechanism of this lesion was analyzed. RESULTS: Physical examination revealed mild weakness in his left hip flexor and quadriceps, ASIA-D motor score of 96. There was no tenderness or step deformity on assessment of his back. The initial roentgenograms showed no evidence of fracture or malalignment. However, evaluation of his computed tomography scan axial images showed a lateral superior endplate fracture, small fracture fragment from T11 right inferior articular process, widening of the left facet joint, and deformed T11 spinous process. The computed tomography scan sagittal images showed a vertical fracture fragment in the central spinal canal. The fragment may have arisen from the posterior cortex of the vertebral body, possibly due to elevation of the PLL. Magnetic resonance imaging (MRI) was obtained due to the suspicion that a much more severe underlying injury was present. The MRI demonstrated disc disruption and high intensity signals in the region of ALL, PLL, ligamentum flavum, supraspinous, and interspinous ligaments as well as in the spinal cord at T11-T12. The MRI also showed high intensity signals in the facet joints at T11-T12. Intraoperative assessment confirmed disruption of the supraspinous and interspinous ligaments, facet capsules and the ligamentum flavum, which was avulsed from its insertion on the underside of the T11 lamina on both sides. There was a tendency during the procedure of the spine to hyperextend, and "fish mouth" at the T11-T12 level, which confirmed the likelihood of this being an extension mechanism. The patient was treated with single segment posterior spine decompression, instrumentation, and fusion. CONCLUSION: A high index of suspicion is necessary to identify such extremely unstable injury despite its relative benign clinical and radiologic presentation.