Posterior Ligamentous Complex Injury Research Articles

Traumatic thoracic spine fracture: can we predict when MRI would modify the fracture classification or decision-making compared to CT alone?

To determine the impact of magnetic resonance imaging (MRI) on fracture classification for thoracic spine fractures (TSFs) compared to computed tomography (CT) alone. This study was a retrospective review of 63 consecutive patients with TSFs who underwent CT and MRI within ten days of injury. Three reviewers classified all fractures according to the AOSpine Classification and the ThoracolumbarAOSpineInjury severity score (TLAOSIS). Posterior ligamentous complex (PLC) injury on MRI was defined by "black stripe discontinuity" and on CT by the presence of vertebral body translation, facet joint malalignment, horizontal laminar or spinous process fracture, and interspinous widening. The proportion of patients with AO type A/B/C and with TLAOSIS ≤ 5 and ≥ 6 was compared between CT and MRI. Classification and regression trees were used to create a series of predictive models for the probability of PLC injury in AO type A fractures. AO classification using CT was as follows: type A in 35 patients (55%), type B in 18 patients (29%), and type C in 10 patients (16%). Thirty-threepatients (52%) had a TLAOSIS ≤5, while the remaining 30 (48%) had TLAOSI ≥6. The addition of MRI after CT upgraded type A to type Bfractures in 10 patients (16%) and changed TL AOSIS from ≤5 to ≥6 in8 cases (12.8%). Type A fractures with load sharing score (LSC) ≥6 had a 60% chance of upgrading to type B, while LSC <6 had a 12.5% chance of upgrading to type B. CT yielded (89%) accuracyin diagnosing PLC injury in TSFs. The addition of MRI after CTsubstantially changed the AO classification or TLAOISS, compared to CT alone, thus suggesting an added value of MRI for PLC assessment for TSFs classification.

The value of the posterior ligamentous complex in traumatic injury of thoracolumbar junction. Part 2. Diagnostic methods

The posterior ligamentous complex (PLC) of the spinal motion segment consists of the supraspinous, interspinous ligaments, ligamentum flavum, and facet joint capsules. The state of this functional combination of ligamentous structures is considered a critical predictor of stability in traumatically injured spine. Despite the practical importance of the PLC concept, it has mainly been used for theoretical evaluation of spinal stability models for a long time. Literature analysis reveals a lack of consensus regarding diagnostic criteria for PLC injuries and their clinical significance. The results of some studies are conflicting. This review attempts to organize information on diagnostic methods for assessing the status of different elements of the PLC in traumatic injuries of the thoracolumbar junction. Currently, there is no universally accepted criteria to help verify PLC injuries. Many signs have diagnostic value, which can be categorized as direct or indirect based on the visualization method. Direct signs are based on the analysis of images that characterize specific anatomical structures. Indirect signs allow for the assessment of the PLC considering the state and location of adjacent, primarily bony, structures. The review examines the diagnostic capabilities of visualization methods such as spondylography, spiral computed tomography, magnetic resonance imaging, and ultrasound with identification of their main advantages and disadvantages. It is found that the broader capabilities of magnetic resonance imaging in visualizing soft tissue structures do not significantly improve diagnostic quality. Spiral computed tomography remains the leading method, both for evaluating bone traumatic changes and determining indirect signs of PLC injury. The development and clinical verification of spiral computed tomography characteristics for assessing the status of the ligamentous apparatus are important tasks in improving the quality of care for patients with thoracolumbar junction injuries.

Predictive Algorithm for Surgery Recommendation in Thoracolumbar Burst Fractures Without Neurological Deficits.

Predictive algorithm via decision tree. Artificial intelligence (AI) remain an emerging field and have not previously been used to guide therapeutic decision making in thoracolumbar burst fractures. Building such models may reduce the variability in treatment recommendations. The goal of this study was to build a mathematical prediction rule based upon radiographic variables to guide treatment decisions. Twenty-two surgeons from the AO Knowledge Forum Trauma reviewed 183 cases from the Spine TL A3/A4 prospective study (classification, degree of certainty of posterior ligamentous complex (PLC) injury, use of M1 modifier, degree of comminution, treatment recommendation). Reviewers' regions were classified as Europe, North/South America and Asia. Classification and regression trees were used to create models that would predict the treatment recommendation based upon radiographic variables. We applied the decision tree model which accounts for the possibility of non-normal distributions of data. Cross-validation technique as used to validate the multivariable analyses. The accuracy of the model was excellent at 82.4%. Variables included in the algorithm were certainty of PLC injury (%), degree of comminution (%), the use of M1 modifier and geographical regions. The algorithm showed that if a patient has a certainty of PLC injury over 57.5%, then there is a 97.0% chance of receiving surgery. If certainty of PLC injury was low and comminution was above 37.5%, a patient had 74.2% chance of receiving surgery in Europe and Asia vs 22.7% chance in North/South America. Throughout the algorithm, the use of the M1 modifier increased the probability of receiving surgery by 21.4% on average. This study presents a predictive analytic algorithm to guide decision-making in the treatment of thoracolumbar burst fractures without neurological deficits. PLC injury assessment over 57.5% was highly predictive of receiving surgery (97.0%). A high degree of comminution resulted in a higher chance of receiving surgery in Europe or Asia vs North/South America. Future studies could include clinical and other variables to enhance predictive ability or use machine learning for outcomes prediction in thoracolumbar burst fractures.

The Influence of Comminution and Posterior Ligamentous Complex Integrity on Treatment Decision Making in Thoracolumbar Burst Fractures Without Neurologic Deficit?

A prospective study. to evaluate the impact of vertebral body comminution and Posterior Ligamentous Complex (PLC) integrity on the treatment recommendations of thoracolumbar fractures among an expert panel of 22 spine surgeons. A review of 183 prospectively collected thoracolumbar burst fracture computed tomography (CT) scans by an expert panel of 22 trauma spine surgeons to assess vertebral body comminution and PLC integrity. This study is a sub-study of a prospective observational study of thoracolumbar burst fractures (Spine TL A3/A4). Each expert was asked to grade the degree of comminution and certainty about the PLC disruption from 0 to 100, with 0 representing the intact vertebral body or intact PLC and 100 representing complete comminution or complete PLC disruption, respectively. ≥45% comminution had a 74% chance of having surgery recommended, while <25% comminution had an 86.3% chance of non-surgical treatment. A comminution from 25 to 45% had a 57% chance of non-surgical management. ≥55% PLC injury certainity had a 97% chance of having surgery, and ≥45-55% PLC injury certainty had a 65%. <20% PLC injury had a 64% chance of having non-operative treatment. A 20 to 45% PLC injury certainity had a 56% chance of non-surgical management. There was fair inter-rater agreement on the degree of comminution (ICC .57 [95% CI 0.52-.63]) and the PLC integrity (ICC .42 [95% CI 0.37-.48]). The study concludes that vetebral comminution and PLC integrity are major dterminant in decision making of thoracolumbar fractures without neurological deficit. However, more objective, reliable, and accurate methods of assessment of these variables are warranted.

Deep learning system for automated detection of posterior ligamentous complex injury in patients with thoracolumbar fracture on MRI

This study aimed to develop a deep learning (DL) algorithm for automated detection and localization of posterior ligamentous complex (PLC) injury in patients with acute thoracolumbar (TL) fracture on magnetic resonance imaging (MRI) and evaluate its diagnostic performance. In this retrospective multicenter study, using midline sagittal T2-weighted image with fracture (± PLC injury), a training dataset and internal and external validation sets of 300, 100, and 100 patients, were constructed with equal numbers of injured and normal PLCs. The DL algorithm was developed through two steps (Attention U-net and Inception-ResNet-V2). We evaluate the diagnostic performance for PLC injury between the DL algorithm and radiologists with different levels of experience. The area under the curves (AUCs) generated by the DL algorithm were 0.928, 0.916 for internal and external validations, and by two radiologists for observer performance test were 0.930, 0.830, respectively. Although no significant difference was found in diagnosing PLC injury between the DL algorithm and radiologists, the DL algorithm exhibited a trend of higher AUC than the radiology trainee. Notably, the radiology trainee's diagnostic performance significantly improved with DL algorithm assistance. Therefore, the DL algorithm exhibited high diagnostic performance in detecting PLC injuries in acute TL fractures.

Letter to the Editor Regarding “Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture”

Letter to the Editor Regarding “Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture”

In Reply to the Letter to the Editor Regarding “Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture”

In Reply to the Letter to the Editor Regarding “Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture”

Analysis of factors associated with proximal junctional kyphosis after surgery for Lenke type 5 adolescent idiopathic scoliosis

Objective: To investigate the risk factors associated with the development of proximal junctional kyphosis (PJK) after posterior spinal fusion for in children with Lenke type 5 adolescent idiopathic scoliosis (AIS). Methods: It was a retrospective case-control study that included medical records of 98 children with Lenke type 5 AIS who underwent posterior orthopedic surgery under general anesthesia at the Honghui Hospital Affiliated to Xi'an Jiaotong University from January 2013 to December 2018. There were 23 males and 75 females with a mean age of (14.5±2.2) years (10-18 years). Patients were divided into PJK and non-PJK groups according to whether the posterior junctional angle (PJA) was greater than 10° and increased for more than 10° from the preoperative period at the the last follow-up. Univariate analysis was used to analyze the correlation of general data of the children with occurrence of PJK after the operation. Multivariate logistic regression analysis was used to analyze the risk factors of postoperative PJK. Results: There were 35 cases in the PJK group and 63 cases in the non-PJK group. The PJK and non-PJK groups were followed up for (35.6±7.3) months and (36.4±7.5) months, respectively, and the difference was not statistically significant (P=0.637). There was no statistically significant difference between the two groups in general data such as gender, age, and body mass index (all P>0.05), while there were statistically significant differences between the two groups in upper instrumented vertebrea (UIV) location and junctional area posterior ligamentous complex (PLC) injury (all P<0.05). The results of univariate analysis showed that UIV location at T10-T12, junctional area PLC injury, preoperative coronal thoracic curve (TC), preoperative and final follow-up PJA, and preoperative and final follow-up pelvic incidence-lumbarlordosis (PI-LL) were correlated with postoperative PJK (OR=2.50, 5.37, 0.92, 1.12, 1.32, 1.06, 3.35, all P<0.05). Multifactorial logistic regression analysis showed that UIV located at T10-T12 (OR=2.346, 95%CI: 1.582-3.481, P=0.001), junctional area PLC injury (OR=5.112, 95%CI: 1.283-20.418, P=0.023) and last follow-up PI-LL (OR=1.826, 95%CI: 1.558-24.745, P=0.012) were risk factors for the occurrence of postoperative PJK in children with Lenke type 5 AIS. Conclusions: Postoperative UIV fixation to the thoracolumbar segment, PLC injury in the junctional area and excessive postoperative PI-LL in children with Lenke type 5 AIS may be the risk factors for the occurrence of PJK after the operation. It is suggested that avoidance of UIV selection to the thoracolumbar segment, intraoperative protection of the PLC located near the UIV and restoration of a good PI-LL relationship may reduce the incidence of PJK.

ROLES OF SPINAL OSTEOTOMIES ON CORRECTION OF POST-TRAUMATIC THORACOLUMBAR KYPHOSIS

Thoracolumbar (T–L) fracture may create focal kyphosis accompanied by altered sagittal alignment, instability and potential neurological deficits. Surgical intervention for post-traumatic T–L kyphosis aims to restore sagittal balance, release compromised neural structures, and to improve the symptoms related to the malalignment. It is best indicated when there is a progression of kyphotic deformity, and/or when there are new or progressive neurological deficits. A kyphotic deformity [Formula: see text] is susceptible to persistent chronic pain in the kyphotic region and surgical correction is often required. Those with posterior ligamentous complex injury may also warrant surgical correction as there is a higher risk of kyphosis progression. A number of surgical procedures could be employed to correct post-traumatic T–L kyphosis. Spinal osteotomies are often needed to improve global, sagittal or coronal balance including in the late and fixed post-traumatic kyphosis. Based on different extent of focal kyphosis and global malalignment, surgical options may include posterior column osteotomy (PCO), pedicle subtraction osteotomy (PSO), disc-bone osteotomy (DBO), vertebral column resection (VCR) or closing opening wedge osteotomy (COWO). The type of spinal osteotomy utilized to correct post-traumatic T–L kyphosis should be chosen based on the severity of the deformity, the alignment of the spine, and the surrounding structures. In the meantime, potential complications should be reduced with novel techniques and proper constructs. When all associated factors are considered, surgical correction composing a suitable spinal osteotomy can be a beneficial and rewarding procedure for patients with post-traumatic T–L kyphosis.

Diagnostic Reliability of Computed Tomography in Predicting Posterior Ligamentous Complex Injury in Traumatic Lower Lumbar Fracture

ObjectiveThough magnetic resonance imaging (MRI) is the primary modality of investigation for determining the extent of PLC injuries in lower lumbar fractures (L3-L5), the reliability of computed tomography (CT) has not been well defined. The main objective of this study is to analyze the diagnostic accuracy of combined CT findings for detecting posterior ligamentous complex injury in patients with lower lumbar fractures. MethodsWe retrospectively analyzed data from 108 patients who presented with traumatic lower lumbar fractures. CT parameters like loss of vertebral body height, local kyphosis, retropulsion of fracture fragment, interlaminar distance (ILD), interspinous distance (ISD), supraspinous distance (SSD), interpedicular distance (IPD), canal compromise, facet joint diastasis in axial images (FJDA) and sagittal images (FJDS), presence of lamina and spinous process fracture were calculated using axial and sagittal CT images. The presence or absence of PLC injury was determined using MRI as a reference standard. ResultsAmong 108 patients PLC injury was identified in 57 (52.8%). On univariate analysis local kyphosis, retropulsion of fracture fragment, ILD, IPD, FJDS, FJDA, and the presence of spinous process fracture were found to be significant (P < 0.05) in predicting PLC injury. Whereas on multivariate logistic regression analysis, FJDS (P= 0.039), and FJDA (P= 0.003) were found to be variables independently associated with PLC injury. ConclusionAmong the various CT parameters, facet joint diastasis (FJDS > 4.2 mm and FJDA > 3.5 mm) is the most reliable factor in determining PLC injury.

Evaluation of Posterior Ligamentous Complex Injury in Thoracolumbar Burst Fractures: Correlation Analysis of CT and MRI Findings.

The goal of this study is to perform correlation analysis of Computed tomography (CT) and magnetic resonance imaging (MRI) results in posterior ligament complex (PLC) injury and define the morphological traits of thoracolumbar (TL) burst fractures connected to PLC injury. Forty patients with surgically repaired TL burst fractures between January 2013 and December 2020 were retrospectively analyzed. The patients were split into two groups for comparison based on MRI (Group P: patients with a confirmed or suspected PLC injury; Group N: patients with PLC injury denied). The radiographic morphological examination based on CT scans and clinical evaluation was performed and compared between two groups. The thoracolumbar injury classification and severity score (TLICS), the load sharing classification (LSC) scores, and the number of patients with neurological impairments were considerably greater in Group P. Loss of height of the fracture (loss height), local kyphosis of the fracture (local kyphosis), and supraspinous distance were significantly higher in Group P and significantly associated with PLC injuries indicating severe vertebral body destruction and traumatic kyphosis in multivariate logistic analysis [odds ratio: 1.90, 1.06, and 1.13, respectively]. Cutoff value for local kyphosis obtained from the receiver operating characteristic curve was 18.8. If local kyphosis is greater than 18.8 degrees on CT scans, we should take into account the probability of the highly damaged burst fracture associated with PLC injury. In this situation, we should carefully assess MRI to identify the spinal cord injury or spinal cord compression in addition to PLC injury because these instances likely present with neurological abnormalities.

Imaging parameters and clinical significance of posterior ligament complex injury in thoracolumbar fracture.

This study aims to investigate whether the combination of radiographs and computed tomography (CT) images can be used as an alternative means of magnetic resonance imaging examination or a preliminary screening method before examination, so as to improve the accuracy of determining the degree of posterior ligament complex injury in thoracolumbar fracture patients. From May 2011 to May 2019, the patients with thoracolumbar fracture were collected. A total of 150 patients were enrolled. The reference standard was 1.5T magnetic resonance imaging examination and lipid suppression sequence was applied. All radiographs and CT imaging results were measured in the Picture Archiving and Communication System workstation. The upper endplate angle and lower endplate angle, the percentage of vertebral height drop, the difference of inter-spinous process distance on CT images and the translation distance were statistically significant between the 2 groups (P < .05). Receiver operating characteristic curve showed that the diagnostic performance was excellent (all area under the curve > 0.7). To sum, the results showed that endplate angle + inter-spinous process distance on CT images combination had relatively high-quality diagnostic value for posterior ligamentous complex injury in thoracolumbar fracture patients.

Correlation between presence of traumatic disco-ligamentous injuries as an MRI finding with the results of management of thoracolumbar and lumbar injuries

Introduction: Radiographic study plays an important role in diagnosis of acute vertebral injuries and helps in proper management of those patients. Magnetic resonance imaging (MRI) is the modality of choice for evaluation of ligamentous and other soft tissue structures, disc, spinal cord and occult osseous injuries. Due to high cost, it is necessary to detect the best use of this technique in the evaluation of thoracolumbar spinal injuries. The purpose of this study was to evaluate the importance of MRI as indicators for vertebral ligamentous injuries and intervertebral disc injuries or herniation in management of thoracolumbar and lumbar fractures. Methods: Retrospective study using radiological measurements. Seventy-two patients with thoracolumbar and lumbar fractures were included. Radiographic parameters detected were percentage of compression, kyphosis angle, vertebral translation and scoliosis angle. Computed tomography was used to detect the degree of spinal canal narrowing, MRI was used to evaluate the condition of posterior ligamentous complex and intervertebral disc injury or herniation. American Spinal Injury Association score was recorded. Results: There were 83% AO spine type A, 6% AO spine type B and 11% AO spine type C. Correlation between fracture type and neurological status with the posterior ligamentous complex injury was found to be significant: ( P = 0.0143 and P = 0.0344, respectively). Degree of vertebral body compression, kyphosis and scoliosis angles, vertebral body translation and spinal canal narrowing were found to be insignificant in correlation with posterior ligamentous complex injuries. Correlation of the above-mentioned parameters with disc injury or herniation was found to be insignificant except for kyphotic angle that was found to be significant in correlation with posttraumatic disc herniation ( P = 0.0219). Conclusion: MRI finding is of great value in management plan of thoracolumbar and lumbar fractures. Injury of posterior ligamentous complex is significantly correlated with fracture severity and the neurological function. But the intervertebral disc injury or herniation was not correlated to them except that the disc herniation was significantly correlated to kyphosis angle.

Which Morphological Features of Facet Diastasis Predict Thoracolumbar Posterior Ligamentous Complex Injury as Defined by Magnetic Resonance Imaging?

The association of various morphological features of facet diastasis with posterior ligamentous complex (PLC) injury has not been previously described. This study aims to determine the diagnostic value of facet diastasis subtypes for diagnosing thoracolumbar PLC injury. We retrospectively reviewed 337 consecutive patients with acute thoracolumbar fractures who had computed tomography (CT) and magnetic resonance imaging (MRI) within 10days of injury. Three and 5 reviewers evaluated MRI and CT images, respectively. Facet diastasis was subclassified as follows: Dislocated, no articular surface apposition; subluxed, incomplete articular surface apposition; and facet fracture articular process fractures which may be displaced ≥2mm or otherwise undisplaced, facet joint widening (FJW) ≥ 3mm. We examined the diagnostic accuracy and the multivariate associations of facet diastasis subtypes with PLC injury in MRI. Facet dislocation, subluxation, and displaced facet fracture yielded a high positive predictive value (PPV) for PLC injury (96%, 88%, and 94%, respectively). In contrast, undisplaced facet fracture and FJW yielded a moderate PPV for PLC injury (78%, and 45%, respectively). Facet dislocation, subluxation, and displaced facet fracture showed independent associations with PLC injury (adjusted odds ratio [AOR]=38.4, 17.1, 13.4, respectively; P<0.05). Undisplaced facet fracture and FJW were not associated with PLC injury (AOR=3.9 [95% confidence interval, 0.49-38.4], P=0.20) and (AOR=1.94 [95% confidence interval, 0.48-7.13]; P=0.20; P= 0.33), respectively. Facet dislocation, subluxation, and displaced facet fracture, but not undisplaced facet fracture or FJW, were independently associated with PLC injury. Therefore, we propose to define facet diastasis as a surrogate marker of PLC injury in MRI based on these morphologies.

Thoracolumbar Injury: The Thoracolumbar Injury Classification and Severity Scoring System or Modified Thoracolumbar Injury Classification and Severity?

To compare the Thoracolumbar Injury Classification and Severity (TLICS) scoring system with its modified (mTLICS) version based on their agreement with the surgeon's opinion regarding treatment for patients with thoracolumbar injuries. Moreover, the Posterior Ligamentous Complex health was compared between intraoperative examinations and magnetic resonance imaging (MRI) reports. MRI was obtained from 114 patients suffering thoracolumbar spinal trauma; the TLICS and mTLICS scores were measured. Approaches 1 and 2 were designed in both scoring systems based on assuming a total score of 4 as surgery and conservative management indication, respectively. Kappa was used to estimate the agreements between each approach and the surgeon's opinion on treatment. The receiver operating curve calculated the appropriate cut-off scores for the above systems over which surgical management was preferred. A P < 0.05 was considered significant. All the approaches showed moderate agreements with the surgeon's opinion on therapeutic management (TLICS: κapproach1=0.557, κapproach2=0.508; mTLICS: κapproach1=0.557, κapproach2=0.551; P < 0.001 for each κ). A score >3.5 best illustrated the indication for surgery in both systems. The radiology report agreed stronger with intraoperatively observed ligamentous health when suspicious cases on MRI were reported as injured (κTLICS= 0.830, κmTLICS= 0.704) rather than healthy (κTLICS= 0.620, κmTLICS= 0.620). The surgeon's treatment plan agreed moderately with suggestions of the TLICS and mTLICS systems; surgery was the preferred management for the patients with a score of 4. Moreover, radiologic suspicion of Posterior Ligamentous Complex injury seemed to indicate a damaged ligament rather than a healthy one.

A Proposal for a Standardized Imaging Algorithm to Improve the Accuracy and Reliability for the Diagnosis of Thoracolumbar Posterior Ligamentous Complex Injury in Computed Tomography and Magnetic Resonance Imaging.

Systematic Literature Review. To propose a systematic imaging algorithm for diagnosing posterior ligamentous complex (PLC) injury in computed tomography (CT) and magnetic resonance imaging (MRI) to improve the reliability of PLC assessment. A systematic review was conducted following PRISMA guidelines. The Scopus database was searched from its inception until July 21, 2022, for studies evaluating CT or MRI assessment of the PLC injury following thoracolumbar trauma. The studies extracted key findings, objectives, injury definitions, and radiographic modalities. Twenty-three studies were included in this systematic review, encompassing 2021 patients. Five studies evaluated the accuracy of MRI in detecting thoracolumbar PLC injury using intraoperative findings as a reference. These studies indicate that black stripe discontinuity due to supraspinous or ligamentum flavum rupture is a more specific criterion of PLC injury than high-signal intensity. Thirteen papers evaluated the accuracy or reliability of CT in detecting thoracolumbar PLC injury using MRI or intraoperative findings as a reference. The overall accuracy rate of CT in detecting PLC injury was 68-90%. Two studies evaluate the accuracy of combined CT findings, showing that ≥2 CT findings are associated with a positive predictive value of 88-91 %. Vertebral translation, facet joint malalignment, spinous process fracture, horizontal laminar fracture, and interspinous widening were independent predictors of PLC injury. We provided a comprehensive imaging algorithm for diagnosing PLC in CT and MRI based on available literature and our experience. The algorithm will potentially improve the accuracy and reliability of PLC assessment, however it needs multicentre prospective validation.

Nonoperative Management in Intact Burst Fracture Patient With Thoracolumbar Injury Classification and Severity Score of 5: A Case Report

Thoracolumbar fractures are a common consequence of trauma, often a result of motor vehicle accidents or falls. Burst fractures are a morphology of thoracolumbar fracture in which compressive force causes retropulsion of the posterior elements of the vertebral body, potentially leading to neurological deficits. The Thoracolumbar Injury Classification and Severity (TLICS) score is a decision-making tool to help surgeons decide between nonoperative and operative management. For assigned scores of 4, management is at the discretion of the surgeon, and for scores ≥ 5, operative treatment is recommended. Burst fracture patients that are neurologically intact are given a score of 5 if there is a posterior ligamentous complex (PLC) injury and are recommended to undergo operative management. Here we present a neurologically intact patient with an L4 burst fracture with PLC injury that was managed conservatively and demonstrated successful clinical, functional, and radiographic recovery.

Evaluation and diagnosis of knee joint diagonal lesion and surgical strategy and effectiveness

To investigate the evaluation, diagnosis, and surgical treatment of knee joint diagonal lesion and to observe its effectiveness. A retrospective analysis was performed on 9 patients with knee joint diagonal lesion admitted between November 2011 and November 2019, including 7 males and 2 females, aged 18-61 years, with an average age of 38.3 years. According to the clinical staging criteria of multiple ligament injury of knee joint, 6 patients with acute stage injury (≤3 weeks), the time from injury to operation was 5-16 days, with an average of 9.3 days; 3 patients with old stage injury (>3 weeks), the time from injury to operation was 7, 12, 144 months, respectively. Posterolateral complex injuries were all type C according to Fanelli classification, and the posterior cruciate ligament injury was grade 3 according to American Medical Association (AMA) classification. According to the three columns classification of tibial plateau fracture, there were 2 cases of zero column fracture and 7 cases of medial column fracture. Patients with acute injury were treated with posterior cruciate ligament reconstruction, posterolateral complex repair and/or reinforcement reconstruction, and tibial plateau fracture was treated with conservative treatment or internal fixation. Patients with malunion of tibial plateau in old stage were treated with limited osteotomy, bone grafting, and internal fixation; the stability of the knee joint was further evaluated during operation, then the posterior cruciate ligament reconstruction and/or posterolateral complex repair and reconstruction were performed as needed. Lysholm score and the International Knee Documentation Committee (IKDC) score before and after operation were used to evaluate knee function and effectiveness. All patients were followed up 24-119 months, with an average of 51.7 months. All the incisions healed by first intention, and no complication such as incision infection, deep venous thrombosis of lower extremities occurred, and there was no reoperation during follow-up. The full-length X-ray films of both lower extremities at 6 months and 1, 2 years after operation showed that the alignment of both lower extremities returned to normal, and the stress position X-ray films showed that the stability in all directions recovered well. The X-ray films of the knee joint at 6 months after operation showed that the fracture of the tibial plateau healed well. At 1 year after operation, MRI showed that the signal of the repaired and reconstructed ligament was good, and there was no reconstruction failure such as ligament absorption or rupture occurred. At 1 year after operation, the muscle strength of the affected limbs was all rated as grade Ⅴ, and the active and passive range of motion of the knee joint recovered to 0°-130°. At 2 years after operation, the Lysholm score and IKDC score significantly improved when compared with those before operation (P<0.05). Knee joint diagonal lesion is a special type of posterior cruciate ligament and posterolateral complex injury with anteromedial split and collapse fracture of tibial plateau, which requires correct evaluation and diagnosis of the injured structure, and detailed surgical and rehabilitation programs to achieve better effectiveness.

In Reply: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Evaluation and Treatment of Patients With Thoracolumbar Spine Trauma: Radiological Evaluation.

To the Editor: We would like to thank the editor for giving us the opportunity to reply to the letter and comments by Dr Aly.1 Radiological evaluation of thoracolumbar fractures is important for fracture classification and deciding the treatment plan. However, there is no consensus on the imaging protocol followed for the evaluation of these fractures. The primary objective of our systematic review was to determine whether the use of MRI to determine ligamentous integrity, in addition to x-rays and computerized tomography (CT), predicted the need for surgical intervention.2 Two of 2278 studies met the inclusion criteria. Winklhofer et al,3 in their retrospective study of 100 patients with thoracolumbar fractures, found that the Arbeitsgemeinschaft fur Osteosynthesefragen classification changed in 31% and the thoracolumbar injury classification and severity classification changed in 33% of patients after MRI review. With the addition of MRI, the Thoracolumbar Injury Classification and Severity score changed from <5 (indication for conservative treatment) to ≥5 (indication for surgery) in 24% of patients.3 Pizones et al4 conducted a prospective study of 30 patients and found that MRI changed the diagnosis in 40% of patients, fracture classification in 24% of fractures, and treatment plan in 16% of patients. However, both these studies provided only level III evidence and included a heterogeneous patient population. Aly et al,5 in their retrospective review of 244 patients with thoracolumbar fractures, included patients with intact neurological status only and diagnosed posterior ligamentous complex (PLC) injury by ≥2 CT findings (instead of one) and black stripe on MRI (instead of high-signal intensity). They used a more robust methodology compared with the previous 2 studies and found that MRI changed the fracture classification by 10% and Thoracolumbar AOSpine Injury Score (TLAOSIS)–based treatment by 20%. They explained the lower rate of fracture reclassification (10% vs 30% reported previously) by differences in sample size, patient population, and CT/MRI criteria for PLC injury. They also provided detailed fracture reclassification rates after MRI for each fracture subtype and TLAOSIS category which may help guide when to get an MRI in patients with thoracolumbar fracture with no neurological deficit. The study by Aly et al1 is commendable because it adds to the current literature on the topic and also addresses some of the drawbacks of the previous studies. However, there are certain limitations of this study such as retrospective, single-institution design, and lack of external validation. We believe that prospective multicenter studies are required to establish these findings. In addition, radiological studies that focus on the characteristics of PLC injury to differentiate between self-healing injuries and injuries that require surgery would be valuable.

Incidence and Associated Factors for Kyphosis Progression in Short-Segment Fixation Thoracolumbar Spine Fractures.

The thoracolumbar spine is the most frequently affected portion of the spine during fractures. In surgical management, short-segment fixation is the treatment of choice because of preserved spine motion and fewer complications. However, this technique causes concerns of kyphosis progression compared with long-segment fixation. The widely used load-sharing classification was of limited value for predicting kyphosis progression in recent literature. The goal of this study was to identify the incidence and explore the factors associated with kyphosis progression in short-segment fixation in thoracolumbar spine fractures. Retrospective cohort study. Patients with thoracolumbar spine fractures and no known neurological deficits treated by short-segment fixation and followed up for at least 12 months during January 2015 to October 2019 were included in this study. Demographic and radiographic data parameters were collected from the hospital database. Incidence of kyphosis progression was collected, and multivariable logistic regression analysis was used to explore associated factors. A total of 91 patients were included in this study. The most common fractures were AO-type A3 in 57.7% of patients, followed by A4 in 31.9%, A2 in 9.9%, and B in 6.6%. Posterior ligamentous complex (PLC) injuries were found in 51.7%. The incidence of kyphosis progression was 35.2%. The PLC was found to be significantly associated with kyphosis progression (OR 3.14, P = 0.040). Intermediate screw insertion was a preventive factor (OR 0.11, P = 0.043). Age, body mass index, and type of fracture were not significant associated factors. The incidence of kyphosis progression was 35.2%. The PLC injury and intermediate screw insertion were significant associated factors. Long-segment fixation in a patient who had PLC injury or intermediate screw insertion should be considered to prevent kyphosis progression. PLC injury was significantly associated with kyphosis progression in short segment thoracolumbar fracture fixation. Therefore, the surgeon should carefully select treatment options for these groups of patients.