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Isolated multiple lumbar transverse process fractures with spinal instability: an uncommon yet serious association

Authors:
Pouya Alijanipour at Methodist Hospitals - NW Indiana
Pouya Alijanipour
  • Methodist Hospitals - NW Indiana
Dylan Greif at University of Miami Miller School of Medicine
Dylan Greif
Nathan Lebwohl at Jackson Memorial Hospital
Nathan Lebwohl
Joseph P Gjolaj at University of Miami Miller School of Medicine
Joseph P Gjolaj
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Abstract and Figures

Purpose Isolated vertebral transverse process fractures of thoracolumbar spine without other vertebral injuries and neurological deficit are generally considered as minor injuries with no concern for associated spinal instability. This report describes a case of multiple lumbar transverse fractures associated with an unexpected yet clinically significant spinal instability. Methods A young male presented with right flank pain following being pushed and trapped against the ground by a reversing truck. The neurological examination was normal, and computed tomography (CT) imaging revealed multiple fractures at right transverse processes from L1 to L5, a single left-sided transverse process fracture at L2 and subtle facet joint distraction without other spinal lesions or visceral injuries. The injury was initially deemed as stable requiring symptomatic treatment and in-patient observation. However, discharge upright X-rays taken in a brace showed marked subluxation of L2/L3 and L3/L4 levels. Results Magnetic resonance imaging revealed significant discoligamentous injuries involving anterior and posterior longitudinal ligaments, annulus fibrosus as well as posterior ligamentous complex. The patient underwent posterior spinal instrumentation and fusion of L1 to L5. Conclusions This is the first case description of association of multisegmental lumbar transverse process fractures with notoriously unstable injuries of the major soft-tissue stabilizers of the spine presenting subtle changes on CT images. When a seemingly benign spinal injury is caused by high-energy trauma, careful scrutiny for associated instability is needed. In this case, the standing in-brace X-ray was able to avoid a misdiagnosis and potentially unfavourable outcome.
Computed tomography: scout view (left) shows a mild lower lumbar curve associated with slight coronal pelvic tilt. The fracture of transverse processes at all lumbar levels on the right side and left L2 can be seen on multiplanar coronal reconstruction (middle). Subtle coronal tilt can be seen at L2/L3 disc level only on one of the coronal images (right, white arrow)
Computed tomography: scout view (left) shows a mild lower lumbar curve associated with slight coronal pelvic tilt. The fracture of transverse processes at all lumbar levels on the right side and left L2 can be seen on multiplanar coronal reconstruction (middle). Subtle coronal tilt can be seen at L2/L3 disc level only on one of the coronal images (right, white arrow)
… 
Computed tomography: midsagittal reconstruction demonstrates an anterior osteophyte at L1/L2 level and increased disc height at L2/L3 without any other malalignment. Right and left parasagittal reconstruction suggests subtle facet joint diastasis at L3/L4 (white arrows)
Computed tomography: midsagittal reconstruction demonstrates an anterior osteophyte at L1/L2 level and increased disc height at L2/L3 without any other malalignment. Right and left parasagittal reconstruction suggests subtle facet joint diastasis at L3/L4 (white arrows)
… 
Computed tomography: the alignment of the pertinent lumbar facet joints look normal on axial images
Computed tomography: the alignment of the pertinent lumbar facet joints look normal on axial images
… 
Anteroposterior radiograph (left) taken in standing position with thoracolumbosacral brace prior to the initially planned discharge showing marked deformity with subluxation of L2/L3 and L3/L4 levels. Lateral radiograph (right) demonstrating narrowing of disc space and mild superimposition of L2 on L3 bodies, regional kyphosis of 5° at L2/L3 level and disproportionate widening of L3/L4 disc
Anteroposterior radiograph (left) taken in standing position with thoracolumbosacral brace prior to the initially planned discharge showing marked deformity with subluxation of L2/L3 and L3/L4 levels. Lateral radiograph (right) demonstrating narrowing of disc space and mild superimposition of L2 on L3 bodies, regional kyphosis of 5° at L2/L3 level and disproportionate widening of L3/L4 disc
… 
Sagittal T2-weighted short tau inversion recovery magnetic resonance imaging showing signal change indicative of injuries of the anterior longitudinal ligament and annulus fibrosus (left, yellow arrow), posterior longitudinal ligament (right, blue arrow) and ligamentum flavum (left, red arrow). Facet distraction can also be seen at L2/L3 interval (right, green arrow). There is also high signal intensity denoting inflammation at posterior subcutaneous tissue
Sagittal T2-weighted short tau inversion recovery magnetic resonance imaging showing signal change indicative of injuries of the anterior longitudinal ligament and annulus fibrosus (left, yellow arrow), posterior longitudinal ligament (right, blue arrow) and ligamentum flavum (left, red arrow). Facet distraction can also be seen at L2/L3 interval (right, green arrow). There is also high signal intensity denoting inflammation at posterior subcutaneous tissue
… 
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Vol.:(0123456789)
1 3
European Spine Journal (2020) 29 (Suppl 2):S127–S132
https://doi.org/10.1007/s00586-019-06105-y
CASE REPORT
Isolated multiple lumbar transverse process fractures withspinal
instability: anuncommon yetserious association
PouyaAlijanipour1,2 · DylanGreif1· NathanH.Lebwohl1· JosephP.Gjolaj1
Received: 16 October 2018 / Revised: 22 June 2019 / Accepted: 7 August 2019 / Published online: 12 August 2019
© Springer-Verlag GmbH Germany, part of Springer Nature 2019
Abstract
Purpose Isolated vertebral transverse process fractures of thoracolumbar spine without other vertebral injuries and neurologi-
cal deficit are generally considered as minor injuries with no concern for associated spinal instability. This report describes
a case of multiple lumbar transverse fractures associated with an unexpected yet clinically significant spinal instability.
Methods A young male presented with right flank pain following being pushed and trapped against the ground by a reversing
truck. The neurological examination was normal, and computed tomography (CT) imaging revealed multiple fractures at
right transverse processes from L1 to L5, a single left-sided transverse process fracture at L2 and subtle facet joint distraction
without other spinal lesions or visceral injuries. The injury was initially deemed as stable requiring symptomatic treatment
and in-patient observation. However, discharge upright X-rays taken in a brace showed marked subluxation of L2/L3 and
L3/L4 levels.
Results Magnetic resonance imaging revealed significant discoligamentous injuries involving anterior and posterior lon-
gitudinal ligaments, annulus fibrosus as well as posterior ligamentous complex. The patient underwent posterior spinal
instrumentation and fusion of L1 to L5.
Conclusions This is the first case description of association of multisegmental lumbar transverse process fractures with
notoriously unstable injuries of the major soft-tissue stabilizers of the spine presenting subtle changes on CT images. When
a seemingly benign spinal injury is caused by high-energy trauma, careful scrutiny for associated instability is needed. In
this case, the standing in-brace X-ray was able to avoid a misdiagnosis and potentially unfavourable outcome.
Keywords Vertebral transverse process· Lumbar spine· Fracture· Posterior ligamentous complex· Stability
Introduction
Isolated transverse process fractures (ITPF) of the thora-
columbar spine without other vertebral lesions are com-
monly found in patients undergoing computed tomogra-
phy (CT) scanning as part of evaluation for spine trauma
in the emergency room (ER). These fractures are gen-
erally considered as stable injuries that should be man-
aged with supportive treatment including pain manage-
ment with or without bracing as well as gradual return to
unrestricted weight bearing as per tolerance. No further
diagnostic workup or surgical intervention is usually rec-
ommended because the major soft-tissue stabilizers of the
spine including anterior longitudinal ligament, posterior
longitudinal ligament, intervertebral disc and posterior
longitudinal complex (PLC, consisting of ligamentum
flavum, facet joint capsule, interspinous ligament and
supraspinous ligament) are not related to the transverse
processes anatomically. In a systematic review of stud-
ies on patients with single or multiple isolated transverse
process fractures, the most common mechanism in the
young population was blunt high-energy trauma such as
motor vehicle accidents and sport-related collisions [1].
Associated injuries to solid and hollow viscera in the
thoracic and abdominal cavities were common indicat-
ing significant amount of energy was involved and the
need for thorough assessment of these patients. However,
none of the 398 patients (including 82 pediatric cases) in
* Pouya Alijanipour
pouya@alijanipour.com
1 Department ofOrthopaedic Surgery, University ofMiami,
CoralGables, USA
2 Department ofOrthopaedic Surgery, University ofMiami
Hospital, 1120 NW 14TH ST Suite 1240, Miami,
FL33136-2107, USA
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... They can be seen at one or more levels in the lumbar vertebra and unilaterally or bilaterally. The most common cause in the young population is blunt high-energy trauma, such as motor vehicle accidents and sport-related collisions, and falling from height [1,4,5]. ...
... Although ITPF fractures are isolated fractures, the possibility of an abdominal injury should be considered. In this context, when this type of fracture is encountered, it is necessary to exclude visceral pathologies secondary to trauma [5,9,10]. ...
... It would be wrong to conclude that ITPFs are a rare fracture type due to the low reporting rates in the literature [2,9]. With the increase in the reporting of these cases in the literature and the widespread use of CT, they have become accepted as the most common type of fracture of the spine [5,17]. Most ITPFs are not fatal and conservative therapy is performed until the fracture is healed [10,18]. ...
Isolated Transverse Process Fractures: Should We Offer Lumbar Corset or Not?
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  • Apr 2024
Background The aim of this study is to emphasize the need to be careful in terms of internal organ injuries in patients with isolated transverse process fracture (ITPF), and to investigate the effectiveness of corset use in controlling acute pain. Methods This is a retrospective study including 72 patients with only transverse process fractures secondary to trauma, who were admitted to the Emergency Department of Sakarya University Research and Training Hospital between January 2020 and October 2022. The radiological diagnoses were collected from spinal vertebral computed tomography images. Twelve patients were excluded from the study due to exclusion criteria. Sixty patients with ITPF were included in the comparison group. All patients were divided into two groups. The group with no lumbar corset (LC) included those who were discharged with analgesic and muscle relaxant treatment without a brace (n = 33). The LC+ group (n = 27) included those who received rigid lumbosacral orthosis in addition to analgesic and muscle relaxant treatment. Pain levels of all cases in both groups were evaluated with Visual Analog Scale scores on the day of trauma, the first week, the first month, and the sixth month. Results A total of 25 cases had one ITPF, 25 had two, 17 had three, and five patients had four or more ITPFs. The hospitalization rate was the highest among patients with four or more ITPFs (40%). Although the hospitalization rates according to the number of ITPFs were not statistically significant (p = 0.528), there was a clinical significance regarding increasing hospitalization rates with the increasing number of ITPFs. The hospitalization rates were 12%, 16%, 17.6%, and 40% in patients with one, two, three, and four or more ITPFs, respectively. Conclusion ITPFs should be treated conservatively. Concomitant organ injuries must be ruled out before treatment. Medical treatment without a lumbar corset could be used as a cost-effective choice.
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Reliability of the evaluation of posterior ligamentous complex injury in thoracolumbar spine trauma with the use of computed tomography scan
Article
Full-text available
  • Apr 2016
  • EUR SPINE J
Purpose The AOSpine thoracolumbar (TL) spine injury classification system is based mainly on computed tomography (CT). The main purpose of this study was to evaluate the reliability of CT scan in the diagnosis of posterior ligamentous complex (PLC) injury in thoracolumbar spine trauma (TLST). Methods We performed a cross-sectional study of 43 patients with TLST. CT scans were evaluated independently by three spine surgeons on two separate occasions, 2 months apart. The reliability of PLC injury parameters was assessed by the Kappa coefficient (κ) and the average percentage of these parameters was established. Injuries were classified according to the AOSpine classification as type A (compression), B (anterior and/or posterior tension band injuries) or C (dislocation) injury and the reliability of the classification was calculated. Results On average, PLC injury was identified in 91.4 % of type B or C injuries. Tension band injury and dislocation were found in 90.5 % of type B and 93.2 % of type C injuries. The intraobserver reliability for the PLC injury parameters ranged from 0.518 to 1.000, except for increased interspinous distance (IID). Interobserver reliability ranged from 0.303 to 0.688. When the patients were evaluated as a whole, dislocation showed the highest κ (0.656 and 0.688). When type A or B injuries were assessed, the highest κ were found for IID (0.533 and 0.511) and tension band injury (0.486 and 0.452). The κ for AOSpine classification was 0.526 and 0.645 in both assessments. Conclusions In this study, the use of CT scan as the only diagnostic tool could identify PLC injury in most cases and demonstrated satisfactory reliability. Dislocation could satisfactorily diagnose type C injury, while IID was the best parameter to differentiate between type A and B injuries.
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AOSpine Thoracolumbar Spine Injury Classification System: Fracture Description, Neurological Status, and Key Modifiers
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Full-text available
  • Nov 2013
STUDY DESIGN: Reliability and agreement study, retrospective case series. OBJECTIVE: To develop a widely accepted, comprehensive yet simple classification system with clinically acceptable intra- and interobserver reliability for use in both clinical practice and research. SUMMARY OF BACKGROUND DATA: Although the Magerl classification and thoracolumbar injury classification system (TLICS) are both well-known schemes to describe thoracolumbar (TL) fractures, no TL injury classification system has achieved universal international adoption. This lack of consensus limits communication between clinicians and researchers complicating the study of these injuries and the development of treatment algorithms. METHODS: A simple and reproducible classification system of TL injuries was developed using a structured international consensus process. This classification system consists of a morphologic classification of the fracture, a grading system for the neurological status, and description of relevant patient-specific modifiers. Forty cases with a broad range of injuries were classified independently twice by group members 1 month apart and analyzed for classification reliability using the Kappa coefficient (κ). RESULTS: The morphologic classification is based on 3 main injury patterns: type A (compression), type B (tension band disruption), and type C (displacement/translation) injuries. Reliability in the identification of a morphologic injury type was substantial (κ= 0.72). CONCLUSION: The AOSpine TL injury classification system is clinically relevant according to the consensus agreement of our international team of spine trauma experts. Final evaluation data showed reasonable reliability and accuracy, but further clinical validation of the proposed system requires prospective observational data collection documenting use of the classification system, therapeutic decision making, and clinical follow-up evaluation by a large number of surgeons from different countries.
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AO spine injury classification system: A revision proposal for the thoracic and lumbar spine
Article
Full-text available
  • Mar 2013
  • EUR SPINE J
PURPOSE: The AO Spine Classification Group was established to propose a revised AO spine injury classification system. This paper provides details on the rationale, methodology, and results of the initial stage of the revision process for injuries of the thoracic and lumbar (TL) spine. METHODS: In a structured, iterative process involving five experienced spine trauma surgeons from various parts of the world, consecutive cases with TL injuries were classified independently by members of the classification group, and analyzed for classification reliability using the Kappa coefficient (κ) and for accuracy using latent class analysis. The reasons for disagreements were examined systematically during review meetings. In four successive sessions, the system was revised until consensus and sufficient reproducibility were achieved. RESULTS: The TL spine injury system is based on three main injury categories adapted from the original Magerl AO concept: A (compression), B (tension band), and C (displacement) type injuries. Type-A injuries include four subtypes (wedge-impaction/split-pincer/incomplete burst/complete burst); B-type injuries are divided between purely osseous and osseo-ligamentous disruptions; and C-type injuries are further categorized into three subtypes (hyperextension/translation/separation). There is no subgroup division. The reliability of injury types (A, B, C) was good (κ = 0.77). The surgeons' pairwise Kappa ranged from 0.69 to 0.90. Kappa coefficients κ for reliability of injury subtypes ranged from 0.26 to 0.78. CONCLUSIONS: The proposed TL spine injury system is based on clinically relevant parameters. Final evaluation data showed reasonable reliability and accuracy. Further validation of the proposed revised AO Classification requires follow-up evaluation sessions and documentation by more surgeons from different countries and backgrounds and is subject to modification based on clinical parameters during subsequent phases.
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Erect Radiographs to Assess Clinical Instability in Patients with Blunt Cervical Spine Trauma
Article
Full-text available
  • Dec 2012
  • J BONE JOINT SURG AM
Computed tomography (CT) and magnetic resonance imaging (MRI) are sensitive modalities for the assessment of the spine, but certain injuries remain poorly assessed with supine radiographs. We describe four cases in which cervical spine injuries were proven as unstable with erect radiographs after being previously evaluated with supine radiographs and CT scans. A retrospective review of medical records and images was used to identify four patients who presented to a teaching hospital from April to December 2010 with unstable cervical spine injuries that were only demonstrated on erect radiographs. All four patients sustained either C4-C5 or C5-C6 injuries. Prior to diagnosis, each had been evaluated with supine radiographs that did not demonstrate instability. Computed tomography identified the osseous injuries that were present but did not provide suitable assessment of stability. Three patients successfully underwent anterior cervical discectomy and fusion. The fourth was managed with a Halo jacket because of major comorbidities. Despite major advances in imaging, these cases highlight the importance of physiological loading and radiographs. The controlled use of erect radiographs to test for clinical instability in patients with cervical spine injuries should be considered except in cases in which instability is already evident on other imaging modalities and/or surgical treatment is already indicated.
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Isolated Transverse Process Fractures: A Systematic Analysis
Article
  • Jan 2017
Objective: To review the literature on isolated transverse process fractures (ITPFs) and provide evidence for and validate the current practice of conservative management. Methods: The PubMed database was searched for published literature related to ITPFs. Baseline patient (age, sex, presentation, mechanism of injury) and fracture (number of fractures, level, single or multi-segmental) characteristics were extracted. Management, and outcomes were also recorded. Statistical comparisons were ascertained through N-1 Pearson Chi-squared tests. Results: A total of 4 studies comprised of 398 patients with 819 ITPFs were evaluated. Mean age was 33.5 years (69% male and 31% female). No patients presented with neurological deficits. The most common mechanism of injury was motor vehicle accident (MVA), followed by falls. MVAs were more commonly the cause of ITPFs in pediatric versus adult patients (88% vs. 65%, p = 0.0001). Falls were more commonly the cause of ITPFs in adults than in children (18% vs. 9%, p = 0.05). Management strategies involved unrestricted movement, bracing and orthotics. Radiologic evidence of spinal instability or deformity was not reported in any of the cases. Mean follow-up was 20.5 months. Conclusions: Our data suggests that non-surgical management of ITPFs leads to complete resolution of the fracture without evidence of permanent neurological deficit or spinal instability. However, interpretation of our results is limited by the paucity of meaningful literature reporting on long-term outcomes. Nevertheless, the results provide support for conservative management and highlights the need to markers or scenarios where the diagnosis of ITPF is actually likely to be erroneous.
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Magnetic Resonance Imaging Following Spine Trauma
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  • Oct 2015
Magnetic resonance imaging (MRI) is used to assess soft-tissue structures following spine trauma; yet, in order to achieve optimum diagnostic accuracy, interpretation must also consider the patient history, physical examination findings, radiographic findings, and computed tomography (CT) findings. ▸The indications for MRI following spinal trauma include progressive neurological deficit with normal radiographic and CT findings, the presence of a neurological deficit (especially a neurological deficit inconsistent with the fracture level), and prior to surgical stabilization in the setting of a facet dislocation. MRI also may be considered for the assessment of obtunded patients and neurologically intact patients with the possibility of instability or facet subluxation-dislocation (relative indications). ▸Moderate concordance exists between MRI and intraoperative findings, and care should be taken to avoid overdiagnosis of injury to the posterior ligamentous complex structures, particularly in patients with minimal or no neurological deficit. ▸Several issues concerning the utility of MRI findings following spine trauma remain debatable. Clinicians should plan the most prudent strategy on the basis of an individualized approach. COPYRIGHT
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The precision, accuracy and validity of detecting posterior ligamentous complex injuries of the thoracic and lumbar spine: A critical appraisal of the literature
Article
  • Dec 2012
  • EUR SPINE J
PURPOSE: The diagnostic assessment and prognostic value of the posterior ligamentous complex (PLC) remains a controversial topic in the management of patients with thoracolumbar spinal injury. The purpose of this review was to critically appraise the literature and present an overview of the: (1) precision, (2) accuracy, and (3) validity of detecting PLC injuries in patients with thoracic and lumbar spine trauma. METHODS: Studies evaluating the precision, accuracy and/or validity of detecting and managing PLC injuries in patients with thoracic and/or lumbar spine injuries were searched through the Medline database (1966 to September 2011). References were retrieved and evaluated individually and independently by two authors. RESULTS: Twenty-one eligible studies were identified. Few studies reported the use of countermeasures for sampling and measurement bias. In nine agreement studies, the PLC was assessed in various ways, ranging from use of booklets to a complete set of diagnostic imaging. Inter-rater and intra-rater kappa values ranged from 0.188 to 0.915 and 0.455 to 0.840, respectively. In nine accuracy studies, magnetic resonance (MR) imaging was most often (n = 6) compared with intra-operative findings. In general, MR imaging tended to demonstrate relatively high negative predictive values and relatively low positive predictive values for PLC injuries. CONCLUSIONS: A wide variety of methods have been applied in the evaluation of precision and accuracy of PLC injury detection, leaving spinal surgeons with a multitude of variable results. There is scant clinical evidence demonstrating the true prognostic value of detected PLC injuries in patients with thoracic and lumbar spine injuries. We recommend the conduct of longitudinal clinical follow-up studies on those cases assessed for precision and/or accuracy of PLC injuries.
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MRI study of post-traumatic incompetence of posterior ligamentous complex: Importance of the supraspinous ligament. Prospective study of 74 traumatic fractures
Article
  • Jun 2012
  • EUR SPINE J
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. 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. χ(2) test and U Mann-Whitney were used for statistics. 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. 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.
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Sequential Damage Assessment of the Different Components of the Posterior Ligamentous Complex After Magnetic Resonance Imaging Interpretation Prospective Study 74 Traumatic Fractures
Article
  • Dec 2011
  • SPINE
Prospective cohort study. To study whether there is a sequential pattern in the posterior ligamentous complex (PLC) rupture caused by deforming traumatic forces by analyzing magnetic resonance (MR) images in a consecutive prospective cohort of patients with traumatic vertebral fracture. PLC plays an important role in vertebral stability. However, the sequence in which the different components of the PLC tear, in the face of traumatic forces, has not been yet described. Prospective study of 74 consecutive vertebral acute traumatic fractures analyzed using radiography and magnetic resonance imaging (MRI) (FS-T2-w/short-tau inversion-recovery [STIR] sequences). Fracture morphology was classified according to the AO classification. Integrity of each PLC component-facet capsules, interspinous ligament (ISL), supraspinous ligament (SSL), and ligamentum flavum (LF)-was assessed and classified as intact, edema, or disruption. ISL edema was further subdivided depending on the extension (>50%/<50%). We analyzed the association between MRI signal and the AO progressive scale of morphological damage. AO type A1/A2 fractures associated with only facet distraction. A3 fractures showed additional ISL edema, usually less than 50%, with neither SSL nor LF disruption. Type B1 fractures associated with facet distraction, ISL edema or disruption, and low rate of SSL/LF disruptions; B2 fractures increased SS/LF disruption rates. Type C fractures associated with facet fracture or dislocation and ISL, SSL, or LF complete rupture. We found high association (P < 0.001) between AO progressive scale and MRI signal. MRI analysis showed that posterior distraction forces begin in the facets and extend throughout the ISL, starting at its posterosuperior margin (finally disinserting the SSL superiorly) and traveling diagonally toward anteroinferior border, finally tearing the LF. MR images correlated with AO progressive scale of morphological damage, which showed a progressive orderly rupture sequence among the different PLC components as traumatic forces increased.
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