AOSpine Classification Systems (Subaxial, Thoracolumbar)

Is there a risk of further displacement of the fractured fragment into the spinal canal in osteoporotic vertebral burst fractures after unilateral PKP? A prospective study

BACKGROUND CONTEXT

The optimal treatment for osteoporotic vertebral burst fracture (OVBF) without neurological symptoms is still a matter of debate.

PURPOSE

To evaluate the safety and efficacy of percutaneous kyphoplasty (PKP) for OVBF.

STUDY DESIGN

The study is a prospective study and is registered in the China Clinical Trials Registry with the registration number ChiCTR-OOC-17013227.

PATIENT SAMPLE

The study involved 119 patients with 137 fractured vertebrae who underwent unilateral PKP for OVBF.

OUTCOME MEASURES

The measurements were carried out independently by two physicians and measured with picture archiving and communication system (PACS) and ImageJ software (National Institutes of Health, Bethesda, MD, USA).

METHODS

The change in the spinal canal area and posterior wall protrusions (PWP) were measured before and after surgery via three-dimensional computed tomographic imaging (CT). Preoperative, postoperative, and final follow-up standing X-rays were used to measure the height of the anterior wall (HAW), height of the posterior wall (HPW), and local kyphotic angle (LKA). Additionally, visual analogue scale (VAS) and the Oswestry Disability Index (ODI) were also determined.

RESULTS

Among the 137 vertebrae assessed, 79 exhibited an increased postoperative canal area, while 57 showed a decrease, with mean values of 8.28±6.871 mm² and -9.04±5.991 mm², respectively. Notably, no significant change in postoperative canal area was identified on the entire dataset (p>.01). There was a significant decrease between median preoperative (3.9 [IQ1-IQ3=3.3-4.8] mm) and postoperative (3.7 [IQ1-IQ3=3.0-4.4] mm) PWP (p<.01). Preoperative and postoperative HAW measurements were 19.4±6.1 mm and 23.2±5.2 mm, respectively (p<.01). However, at the final follow-up, the HAW was lower than the postoperative value. The HPW was also significantly improved after surgery (p<.01), but at the final follow-up, it was significantly decreased compared with the postoperative measurement. Following surgery, KA was significantly corrected (p<.01); however, at the final follow-up, relapse was detected (average KA: 18.4±10.3°). At the final follow-up, both VAS and ODI were significantly improved compared with the preoperative period (p<.01). As for complications, 50 patients experienced cement leakage, and 16 patients experienced vertebral refracture. All patients did not develop neurological symptoms during the follow-up.

CONCLUSIONS

OVBF without neurological deficits showed significant improvement in symptoms during the postoperative period after PKP. There was no notable alteration in the spinal canal area, but a significant decrease in PWP was observed. Consequently, we posit that PKP stands as a secure and efficacious surgical intervention for treating OVBF cases devoid of neurological symptoms.

Reliability of thoracolumbar burst fracture classification in the Swedish Fracture Register

BACKGROUND

The Swedish Fracture Register (SFR) is a national quality register for all types of fractures in Sweden. Spine fractures have been included since 2015 and are classified using a modified AOSpine classification. The aim of this study was to determine the accuracy of the classification of thoracolumbar burst fractures in the SFR.

METHODS

Assessments of medical images were conducted in 277 consecutive patients with a thoracolumbar burst fracture (T10-L3) identified in the SFR. Two independent reviewers classified the fractures according to the AOSpine classification, with a third reviewer resolving disagreement. The combined results of the reviewers were considered the gold standard. The intra- and inter-rater reliability of the reviewers was determined with Cohen's kappa and percent agreement. The SFR classification was compared with the gold standard using positive predictive values (PPV), Cohen's kappa and percent agreement.

RESULTS

The reliability between reviewers was  high (Cohen's kappa 0.70-0.97). The PPV for correctly classifying burst fractures in the SFR was high irrespective of physician experience (76-89%), treatment (82% non-operative, 95% operative) and hospital type (83% county, 95% university). The inter-rater reliability of B-type injuries and the overall SFR classification compared with the gold standard was low (Cohen's kappa 0.16 and 0.17 respectively).

CONCLUSIONS

The SFR demonstrates a high PPV for accurately classifying burst fractures, regardless of physician experience, treatment and hospital type. However, the reliability of B-type injuries and overall classification in the SFR was found to be low. Future studies on burst fractures using SFR data where classification is important should include a review of medical images to verify the diagnosis.

Surgical management of lower limb radiculopathy following acute singe-level osteoporotic vertebral fracture of lower lumbar spine in geriatric patient: a retrospective study

BACKGROUND

Radiculopathy of the lower limb after acute osteoporotic vertebral fractures (OVFs) in the lower lumbar spine is uncommon in geriatric patients. Moreover, surgical intervention is generally recommended in patients who are irresponsive to conservative treatment. Determining an optimum surgical strategy is challenging considering the poor general condition of this population. Thus, herein, we established an algorithm for surgically managing this clinical scenario, hoping to provide a reference for making a surgical decision.

METHODS

We retrospectively studied patients who suffered from new-onset radiculopathy of the lower limb after acute single-level OVFs in the lower lumbar spine and eventually underwent surgical intervention at our department. Information on the demographics, bone quality, AO spine classification of the vertebral fracture, pre-existing degenerative changes, including foraminal stenosis and lumbar disc herniation, and surgical intervention type was collected. Additionally, clinical outcomes, including preoperative and postoperative visual analog scale (VAS) scores for back and leg pain, Oswestry disability index (ODI), and MacNab criterion for response to surgery, were evaluated.

RESULTS

From September 2019 to December 2021, a total of 22 patients with a mean age of 68.59 ± 9.74 years were analyzed. The most involved vertebra was L5 (54.5%), followed by L4 (27.3%) and L3 (18.2%). Among the 22 patients, 15 (68.2%) were diagnosed with the A1 type fracture of AO classification, and among them, 11 (73.3%) were characterized by the collapse of the inferior end plate (IEP). Three patients (13.6%) suffered from A2-type fractures, whereas four patients (18.2%) suffered from A3-type fractures. Pre-existing degenerative changes were observed in 12 patients (54.5%) of the patients. A total of 16 patients (72.7%) were treated by percutaneous kyphoplasty (PKP). Additionally, three patients underwent posterior instrumentation and fusion, two patients underwent a secondary endoscopic foraminoplasty, and one patient underwent a secondary radiofrequency ablation. The mean follow-up period was 17.42 ± 9.62 months. The mean VAS scores for leg and back pain and ODI decreased significantly after the surgery (P < 0.05). The total satisfaction rate at the last follow-up was 90.9% per the Macnab criterion.

CONCLUSION

Patients with OVFs in the IEP are predisposed to suffer from radiculopathy of the lower limb. PKP alone or in combination with other minimally invasive surgical strategies is safe and effective in treating stable fractures. Additionally, aggressive surgical intervention should be considered in patients with unstable fractures or severe foraminal encroachment.

Adverse events after surgery for injuries to the subaxial cervical spine: analysis of incidence and risk factors

PURPOSE

To determine the incidence of severe surgical adverse events (sSAE) after surgery of patients with subaxial cervical spine injury (sCS-Fx) and to identify patient, treatment, and injury-related risk factors.

METHODS

Retrospective analysis of clinical and radiological data of sCS-Fx patients treated surgically between 2010 and 2020 at a single national trauma center. Baseline characteristics of demographic data, preexisting conditions, treatment, and injury morphology were extracted. Incidences of sSAEs within 60 days after surgery were analyzed. Univariate analysis and binary logistic regression for the occurrence of one or more sSAEs were performed to identify risk factors. P-values < .05 were considered statistically significant.

RESULTS

Two hundred and ninety-two patients were included. At least one sSAE occurred in 49 patients (16.8%). Most frequent were sSAEs of the surgical site (wound healing disorder, infection, etc.) affecting 29 patients (9.9%). Independent potential risk factors in logistic regression were higher age (OR 1.02 [1.003-1.04], p = .022), the presence of one or more modifiers in the AO Spine Subaxial Injury Classification (OR 2.02 [1.03-3.96], p = .041), and potentially unstable or unstable facet injury (OR 2.49 [1.24-4.99], p = .010). Other suspected risk factors were not statistically significant, among these Injury Severity Score, the need for surgery for concomitant injuries, the primary injury type according to AO Spine, and preexisting medical conditions.

CONCLUSION

sSAE rates after treatment of sCS-Fx are high. The identified risk factors are not perioperatively modifiable, but their knowledge should guide intra and postoperative care and surgical technique.

The AO Spine Thoracolumbar Injury Classification System and Treatment Algorithm in Decision Making for Thoracolumbar Burst Fractures Without Neurologic Deficit

STUDY DESIGN

Prospective Observational Study.

OBJECTIVE

To determine the alignment of the AO Spine Thoracolumbar Injury Classification system and treatment algorithm with contemporary surgical decision making.

METHODS

183 cases of thoracolumbar burst fractures were reviewed by 22 AO Spine Knowledge Forum Trauma experts. These experienced clinicians classified the fracture morphology, integrity of the posterior ligamentous complex and degree of comminution. Management recommendations were collected.

RESULTS

There was a statistically significant stepwise increase in rates of operative management with escalating category of injury (P < .001). An excellent correlation existed between recommended expert management and the actual treatment of each injury category: A0/A1/A2 (OR 1.09, 95% CI 0.70-1.69, P = .71), A3/4 (OR 1.62, 95% CI 0.98-2.66, P = .58) and B1/B2/C (1.00, 95% CI 0.87-1.14, P = .99). Thoracolumbar A4 fractures were more likely to be surgically stabilized than A3 fractures (68.2% vs 30.9%, P < .001). A modifier indicating indeterminate ligamentous injury increased the rate of operative management when comparing type B and C injuries to type A3/A4 injuries (OR 39.19, 95% CI 20.84-73.69, P < .01 vs OR 27.72, 95% CI 14.68-52.33, P < .01).

CONCLUSIONS

The AO Spine Thoracolumbar Injury Classification system introduces fracture morphology in a rational and hierarchical manner of escalating severity. Thoracolumbar A4 complete burst fractures were more likely to be operatively managed than A3 fractures. Flexion-distraction type B injuries and translational type C injuries were much more likely to have surgery recommended than type A fractures regardless of the M1 modifier. A suspected posterior ligamentous injury increased the likelihood of surgeons favoring surgical stabilization.

Diagnostic accuracy of an artificial intelligence algorithm versus radiologists for fracture detection on cervical spine CT

OBJECTIVES

To compare diagnostic accuracy of a deep learning artificial intelligence (AI) for cervical spine (C-spine) fracture detection on CT to attending radiologists and assess which undetected fractures were injuries in need of stabilising therapy (IST).

METHODS

This single-centre, retrospective diagnostic accuracy study included consecutive patients (age ≥18 years; 2007-2014) screened for C-spine fractures with CT. To validate ground truth, one radiologist and three neurosurgeons independently examined scans positive for fracture. Negative scans were followed up until 2022 through patient files and two radiologists reviewed negative scans that were flagged positive by AI. The neurosurgeons determined which fractures were ISTs. Diagnostic accuracy of AI and attending radiologists (index tests) were compared using McNemar.

RESULTS

Of the 2368 scans (median age, 48, interquartile range 30-65; 1441 men) analysed, 221 (9.3%) scans contained C-spine fractures with 133 IST. AI detected 158/221 scans with fractures (sensitivity 71.5%, 95% CI 65.5-77.4%) and 2118/2147 scans without fractures (specificity 98.6%, 95% CI 98.2-99.1). In comparison, attending radiologists detected 195/221 scans with fractures (sensitivity 88.2%, 95% CI 84.0-92.5%, p < 0.001) and 2130/2147 scans without fracture (specificity 99.2%, 95% CI 98.8-99.6, p = 0.07). Of the fractures undetected by AI 30/63 were ISTs versus 4/26 for radiologists. AI detected 22/26 fractures undetected by the radiologists, including 3/4 undetected ISTs.

CONCLUSION

Compared to attending radiologists, the artificial intelligence has a lower sensitivity and a higher miss rate of fractures in need of stabilising therapy; however, it detected most fractures undetected by the radiologists, including fractures in need of stabilising therapy. Clinical relevance statement The artificial intelligence algorithm missed more cervical spine fractures on CT than attending radiologists, but detected 84.6% of fractures undetected by radiologists, including fractures in need of stabilising therapy.

KEY POINTS

The impact of artificial intelligence for cervical spine fracture detection on CT on fracture management is unknown. The algorithm detected less fractures than attending radiologists, but detected most fractures undetected by the radiologists including almost all in need of stabilising therapy. The artificial intelligence algorithm shows potential as a concurrent reader.

Standalone Percutaneous Vertebroplasty for Hyperextension Injuries of the Ankylosed Thoracolumbar Spinal Kyphosis

Hyperextension injuries of the ankylosed thoracolumbar spine, particularly those with preexisting kyphotic deformity, present significant therapeutic challenges. The authors viewed that such injuries without displacement or fractures of the posterior elements are reasonable candidates for standalone percutaneous vertebroplasty (PVP). In such cases, the posterior tension band is spared; thus, fractures are unstable not in the lateral direction, which would lead to the translation of the fracture, but in the vertical direction. Such vertical instability of the fracture can be stabilized if the open mouth-type vertebral cleft is adequately filled with a sufficiently large amount of polymethylmethacrylate (PMMA) cement. Our three patients receiving standalone PVP received injections of 12 mL, 16.5 mL, and 18 mL of PMMA cement. This minimally invasive surgical procedure achieved both short-term (immediate pain relief and mobilization) and long-term (fracture healing) goals.

Pelvis-Sacrum-Lumbar Spine Injury Characteristics From Underbody Blast Loading

INTRODUCTION

Combat-related injuries from improvised explosive devices occur commonly to the lower extremity and spine. As the underbody blast impact loading traverses from the seat to pelvis to spine, energy transfer occurs through deformations of the combined pelvis-sacrum-lumbar spine complex, and the time factor plays a role in injury to any of these components. Previous studies have largely ignored the role of the time variable in injuries, injury mechanisms, and warfighter tolerance. The objective of this study is to relate the time or temporal factor using a multi-component, pelvis-sacrum-lumbar spinal column complex model.

MATERIALS AND METHODS

Intact pelvis-sacrum-spine specimens from pre-screened unembalmed human cadavers were prepared by fixing at the superior end of the lumbar spine, pelvis and abdominal contents were simulated, and a weight was added to the cranial end of the fixation to account for torso effective mass. Prepared specimens were placed on the platform of a custom vertical accelerator device and aligned in a seated soldier posture. An accelerometer was attached to the seat platen of the device to record the time duration to peak velocity. Radiographs and computed tomography images were used to document and associate injuries with time duration.

RESULTS

The mean age, stature, weight, body mass index, and bone density of 12 male specimens were as follows: 65 ± 11 years, 1.8 ± 0.01 m, 83 ± 13 kg, 27 ± 5.0 kg/m2, and 114 ± 21 mg/cc. They were equally divided into short, medium, and long time durations: 4.8 ± 0.5, 16.3 ± 7.3, and 34.5 ± 7.5 ms. Most severe injuries associated with the short time duration were to pelvis, although they were to spine for the long time duration.

CONCLUSIONS

With adequate time for the underbody blast loading to traverse the pelvis-sacrum-spine complex, distal structures are spared while proximal/spine structures sustain severe/unstable injuries. The time factor may have implications in seat and/or seat structure design in future military vehicles to advance warfighter safety.

Vertebral compression fractures managed with brace: risk factors for progression

PURPOSE

The aim of this study is to identify risk factors for vertebral compression fracture (VCF) progression in patients treated conservatively with a brace. Then, a case-control study was designed.

METHODS

All patients over 50 years old with diagnosis of thoracic or lumbar VCF (T5 to L5) in absence of underlying oncological process, treated conservatively with brace, and consecutively attended at our department from January 2017 to June 2021 were retrospectively selected for analysis. Patients missed for follow-up or dead during the first 3 months of follow-up were excluded.

RESULTS

Five hundred and eighty-two consecutive patients were recorded. Incomplete follow-up excluded 74 patients and other 19 died in the first three months after diagnosis, so 489 cases were finally analyzed. Median follow-up was 21 (IQR 13;30) weeks. Increased collapse of the vertebral body was found in 29.9% of VCFs with a median time to progression of 9 (IQR 7;13) weeks. Male gender (OR 1.6), type A3 fracture of the AOSpine classification (OR 2.7), thoracolumbar junction location (OR 1.7), and incorrect use of the brace (OR 3.5) were identified as independent risk factors for progression after multivariable analysis.

CONCLUSION

Male gender, type A3 fracture of the AOSpine classification, thoracolumbar junction location, and incorrect use of the brace were identified as independent risk factors for VCF progression, which resulted in worse pain control, when treated with brace. Thus, other treatments such as percutaneous vertebral augmentation could be considered to avoid progression in selected cases, since collapse rate has been demonstrated lower with these procedures.

Cervical, thoracolumbar, and sacral spine trauma classifications: past, present, and future

OBJECTIVE

Traumatic spine injuries are a relatively common occurrence and are associated with functional impairment, loss of neurologic function, and spinal deformity. A number of spinal trauma classification systems have been developed with varying degrees of acceptance. This review provides a chronological overview of spinal trauma classification systems, with special consideration towards the benefits and pitfalls related to each. Cervical, thoracolumbar, and sacral trauma classification systems are discussed.

METHODS

A review of the literature was performed. Published articles that reported on bony spinal trauma classification systems were examined. No year exemptions were identified. The reference lists of all selected articles were screened for additional studies. Article inclusion and exclusion criteria were defined a priori.

RESULTS

A total of 20 classification systems were identified from years 1938-2017. Of these 20 classification systems, 6 were cervical, 11 were thoracolumbar and 3 were sacral. The modernization of bony spinal trauma classification has been characterized by the development of weighted scales that include injury morphology, integrity of associated ligamentous structures and neurologic status.

CONCLUSION

For widespread acceptance and adoption in the clinical setting, future spinal trauma scoring classification will need to remain simple, highly reproducible, and impart information with regard to clinical decision-making and prognosis that may be effectively communicated across each medical specialty involved in the care of these patients.

Thoracolumbar vertebral fracture in unoperated idiopathic scoliosis

INTRODUCTION

Traumatic fractures of the thoracolumbar spine are common. Their management considers the fracture type according to the various classifications in existence, as well as the patient's background and age. In some cases, the occurrence of a fracture on a spine with an unoperated scoliotic deformity can be observed. This entity, not described in the literature, can pose a therapeutic challenge and is not present in any existing treatment algorithm. The main objective of this work was to describe the characteristics and management of vertebral fractures in patients with unoperated idiopathic scoliosis.

MATERIAL AND METHODS

We carried out a monocentric retrospective study in all patients operated on for a spinal fracture between May 2011 and August 2020, with a history of unoperated adolescent idiopathic scoliosis. We collected epidemiological data including the surgical course of each patient and the final result. The patients were categorized according to the surgical strategy (extensive fusion and correction of the deformity, short osteosynthesis without considering the scoliosis, vertebroplasty and orthopedic treatment) and the final clinical and radiological result evaluated at the last follow-up.

RESULTS

Ten patients were included in this study with a total number of 16 fractured vertebrae. The population was 80% female, with an average age of 36.3 years. The majority of fractures were type A, at the thoracolumbar junction. The curves were classified as Lenke 1A in 5 cases, 1B in 2 cases, 1C in 1 case and 5C for 2 patients. Ultimately, 3 patients underwent extended fusion with correction of scoliosis, 6 localized osteosynthesis and 1 percutaneous vertebroplasty. In 50% of cases, a change of surgical strategy had to be made, due to worsening of the deformity or hyperalgesia. The last follow-up was at 19.7 months on average. Five patients had a good final clinical result, 5 patients had persistence of significant pain (lower back pain or cruralgia).

CONCLUSION

This is the first study investigating the association of vertebral fractures and the presence of unoperated idiopathic scoliosis. The results of our study highlight the management challenges and difficulties in therapeutic decision-making. The presence of a pre-existing curve is thus an important parameter to consider and should lead to the discussion of performing an extended fusion secondarily in view of the risk of poor results from localized surgery.

LEVEL OF EVIDENCE

IV.

Integrated spine trauma team protocol: Combined neurosurgical and orthopedic experience for the management of traumatic spinal injuries

Objectives

During the last decades, spine surgery has grown exponentially. In spite of that, it remains a surgical specialty without a well-defined own certification. It is usually carried out, separately, by neurosurgeons and orthopedic surgeons, even if there is an overlapping of competence and skills.

Materials and Methods

In our hospital, from January 2019, a systematic protocol called integrated spine trauma team protocol (ISTTP) was implemented to improve the management of traumatic spinal injuries in a multidisciplinary way. It is characterized by a specific algorithm from diagnosis to postoperative care. According to the new protocol, orthopedic spinal surgeons and neurosurgeons work together as an integrated spine trauma team. The authors analyzed, retrospectively, the results obtained by comparing patients treated before and after the application of the ISTTP.

Results

The new protocol allowed a statistically significant reduction in waiting time before surgery and complication rate. Moreover, early discharge of patients was recorded. To the best of our knowledge, this is the first study that described a specific algorithm for a standardized multidisciplinary management of the spinal trauma with combined orthopedic and neurosurgeon expertise.

Conclusion

Our preliminary results suggest that the application of our ISTTP leads to better results for treating traumatic spinal injury (TSI).

CT Scan in Subaxial Cervical Facet Injury: Is It Enough for Decision-Making?

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

Assessment of subaxial cervical facet injuries using the AO Spine Subaxial Cervical Spine Injury Classification System is based on CT scan findings. However, additional radiological evaluations are not directly considered. The aim of this study is to determine situations in which spine surgeons request additional radiological exams after a facet fracture.

METHODS

A survey was sent to AO Spine members from Latin America. The evaluation considered demographic variables, routine use of the Classification, as well as the timepoint at which surgeons requested a cervical MRI, a vascular study, and/ or dynamic radiographs before treatment of facet fractures.

RESULTS

There was 229 participants, mean age 42.9 ± 10.2 years; 93.4% were men. Orthopedic surgeons 57.6% with 10.7 ± 8.7 years of experience in spine surgery. A total of 86% used the Classification in daily practice. An additional study (MRI/vascular study/and dynamic radiographs) was requested in 53.3%/9.6%/43.7% in F1 facet injuries; 76.0%/20.1%/50.2% in F2; 89.1%/65.1%/28.4% in F3; and 94.8%/66.4%/16.6% in F4. An additional study was frequently required: F1 72.5%, F2 86.9%, F3 94.7%, and F4 96.1%.

CONCLUSIONS

Spine surgeons generally requested additional radiological evaluations in facet injuries, and MRI was the most common. Dynamic radiographs had a higher prevalence for F1/F2 fractures; vascular studies were more common for F3/F4 especially among surgeons with fewer years of experience. Private hospitals had a lower spine trauma cases/year and requested more MRI and more dynamic radiographs in F1/F2. Neurosurgeons had more vascular studies and dynamic radiographs than orthopedic surgeons in all facet fractures.

Evaluation of vertebral shortening and interbody fusion with short segment pedicle screw fixation for unstable thoracolumbar fractures

Background

Various operative procedures have been described for the treatment of traumatic paraplegia caused by unstable thoracolumbar fractures. We prospectively evaluated interbody fusion (IBF) with SS-PSF in these cases with regard to clinico-radiological outcome with the objectives: (1) Does IBF and short segment pedicle screw fixation (SS-PSF) prevent progression of kyphotic angle after surgery? (2) Can this procedure be safely performed in the setting of acute trauma?.

Methods

Sixteen patients suffering from traumatic paraplegia caused by acute unstable thoracolumbar fractures were enrolled prospectively and underwent IBF with SS-PSF. They were evaluated for magnitude of shortening in spine, progression of kyphotic angle, and neurological improvement by American spinal injury association scale (ASIA).

Results

Out of total sixteen, 14 patients were ASIA grade A and 2 were grade C, at the time of presentation. Thirteen out of these 14 remained grade A and one improved to B. Both the patients who had grade C involvement at the time of presentation improved to grade D at one-year follow-up. The mean blood loss was 750 ml (range; 650 ml-1150 ml). Mean kyphotic angle decreased from 20.6° (range; 13° to 37°) preoperatively to 6.2° (range; 3° to 10°) at postoperative day 2 (p = 0.002). Its mean value after 6 months was 6.5° (range; 3° to 11°). The procedure resulted in mean spinal column shortening of 18 mm (range; 16 mm-22 mm) in the spinal column. All the patients achieved bony union by a mean duration of 3.9 months (range; 3 months-6 months).

Conclusions

IBF with SS-PSF has the shortest possible instrumented construct for thoracolumbar junction fusion done by posterior approach. The interbody fusion for unstable thoracolumbar junction fractures prevents the progression of kyphotic angle post-operatively.

Level of evidence

Level 4.

Matrix Stiffness Activating YAP/TEAD1-Cyclin B1 in Nucleus Pulposus Cells Promotes Intervertebral Disc Degeneration

Intervertebral disc degeneration is a leading cause of disability in the elderly population. Rigid extracellular matrix is a critical pathological feature of disc degeneration, leading to aberrant nucleus pulposus cells (NPCs) proliferation. However, the underlying mechanism is unclear. Here, we hypothesize that increased matrix stiffness induces proliferation and thus degenerative phenotypes of NPCs through YAP/TEAD1 signaling pathway. We established hydrogel substrates to mimic stiffness of degenerated human nucleus pulposus tissues. RNA-sequencing identified differentially expressed genes between primary rat NPCs cultured on rigid and soft hydrogels. Dual luciferase assay and gain- and loss-function experiments evaluated the correlation between YAP/TEAD1 and Cyclin B1. Furthermore, single-cell RNA-sequencing of human NPCs was performed to identify specific cell clusters with high YAP expression. Matrix stiffness increased in severely degenerated human nucleus pulposus tissues (p < 0.05). Rigid substrate enhanced rat NPCs proliferation mainly through Cyclin B1, which was directly targeted and positively regulated by YAP/TEAD1. Depletion of YAP or Cyclin B1 arrested G2/M phase progression of rat NPCs and reduced fibrotic phenotypes including MMP13 and CTGF (p < 0.05). Fibro NPCs with high YAP expression were identified in human tissues and responsible for fibrogenesis during degeneration. Furthermore, inhibition of YAP/TEAD interaction by verteporfin suppressed cell proliferation and alleviated degeneration in the disc needle puncture model (p < 0.05). Our results demonstrate that elevated matrix stiffness stimulates fibro NPCs proliferation through YAP/TEAD1-Cyclin B1 axis, indicating a therapeutic target for disc degeneration.

Does displacement of cervical and thoracolumbar dislocation-translation injuries predict spinal cord injury or recovery?

OBJECTIVE

For patients with cervical and thoracolumbar AO Spine type C injuries, the authors sought to 1) identify whether preoperative vertebral column translation is predictive of a complete spinal cord injury (SCI) and 2) identify whether preoperative or postoperative vertebral column translation is predictive of neurological improvement after surgical decompression.

METHODS

All patients who underwent operative treatment for cervical and thoracolumbar AO Spine type C injuries at the authors' institution between 2006 and 2021 were identified. CT and MRI were utilized to measure vertebral column translation in millimeters prior to and after surgery. A receiver operating characteristic (ROC) curve was generated to predict the probability of sustaining a complete SCI on the basis of the amount of preoperative vertebral column translation. ROC curves were then used to predict the probability of neurological recovery on the basis of preoperative and postoperative vertebral column translation.

RESULTS

ROC analysis of 67 patients identified 6.10 mm (area under the curve [AUC] 0.77, 95% CI 0.650-0.892) of preoperative vertebral column translation as predictive of complete SCI. Additionally, ROC curve analysis found that 10.4 mm (AUC 0.654, 95% CI 0.421-0.887) of preoperative vertebral column translation was strongly predictive of no postoperative neurological improvement. Residual postoperative vertebral column translation after fracture reduction and instrumentation had no predictive value on neurological recovery (AUC 0.408, 95% CI 0.195-0.622).

CONCLUSIONS

For patients with cervical and thoracolumbar AO Spine type C injuries, the amount of preoperative vertebral column translation is highly predictive of complete SCI and the likelihood of postoperative neurological recovery.

A 20-Year Review of Biomechanical Experimental Studies on Spine Implants Used for Percutaneous Surgical Repair of Vertebral Compression Fractures

A vertebral compression fracture (VCF) is an injury to a vertebra of the spine affecting the cortical walls and/or middle cancellous section. The most common risk factor for a VCF is osteoporosis, thus predisposing the elderly and postmenopausal women to this injury. Clinical consequences include loss of vertebral height, kyphotic deformity, altered stance, back pain, reduced mobility, reduced abdominal space, and reduced thoracic space, as well as early mortality. To restore vertebral mechanical stability, overall spine function, and patient quality of life, the original percutaneous surgical intervention has been vertebroplasty, whereby bone cement is injected into the affected vertebra. Because vertebroplasty cannot fully restore vertebral height, newer surgical techniques have been developed, such as kyphoplasty, stents, jacks, coils, and cubes. But, relatively few studies have experimentally assessed the biomechanical performance of these newer procedures. This article reviews over 20 years of scientific literature that has experimentally evaluated the biomechanics of percutaneous VCF repair methods. Specifically, this article describes the basic operating principles of the repair methods, the study protocols used to experimentally assess their biomechanical performance, and the actual biomechanical data measured, as well as giving a number of recommendations for future research directions.

Thoracic and lumbar spine trauma classification systems fail to predict post-traumatic kyphotic deformity

Background

Post-traumatic kyphosis of the thoracic and lumbar spine can lead to pain and decreased function. MRI has been advocated to assess ligament integrity and risk of kyphosis.

Methods

All thoracic and lumbar spine MRI performed for evaluation of trauma over a 3-year period at a single institution were reviewed. Patients were included if there was an MRI showing a vertebral body fracture and follow-up radiographs. Two observers retrospectively reviewed all radiographs, CT and MRI scans, and classified injuries based on the Denis, TLICS, AO and load sharing classification systems. Change in kyphosis between injury and follow-up studies was measured. The initial radiology reports made at time of patient injury were compared to the retrospective interpretations.

Results

There were 67 separate injuries in 62 patients. Kyphosis measuring ≥ 10° developed despite an intact PLC in 6/14 nonoperative cases, and 3/7 surgically treated cases; when PLC was partially injured, it developed in 6/10 cases (8 treated nonoperatively, 2 treated operatively. Thirty injuries had complete disruption of PLC by MRI, 24 treated with fusion. Kyphosis ≥ 10° developed in 3/6 treated nonoperatively, and 8/24 treated with fusion. Development of kyphosis was independent of degree of vertebral body comminution. It developed equally in patients with Grade 2 and Grade 3 Denis injuries. It developed in patients with intact PLC when multiple vertebrae were involved and/or there was compressive injury to anterior longitudinal ligament (ALL). There was high interobserver variability in assessment of severity of ligamentous injury on MRI.

Conclusions

Classification systems of thoracic and lumbar spine injury and integrity of the PLC failed to predict the risk of development of post-traumatic kyphotic deformity.

The Subaxial Cervical AO Spine Injury Score

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

To develop an injury score for the AO Spine Subaxial Cervical Spine Injury Classification System.

METHODS

Respondents numerically graded each variable within the classification system for severity. Based on the results, and with input from the AO Spine Trauma Knowledge Forum, the Subaxial Cervical AO Spine Injury Score was developed.

RESULTS

An A0 injury was assigned an injury score of 0, A1 a score of 1, and A2 a score of 2. Given the significant increase in severity, A3 was given a score of 4. Based on equal severity assessment, A4 and B1 were both assigned a score of 5. B2 and B3 injuries were assigned a score of 6. Unstable C-type injuries were given a score of 7. Stable F1 injuries were assigned a score of 2, with a 2-point increase for F2 injuries. Likewise, F3 injuries received a score of 5, whereas more unstable F4 injuries a score of 7. Neurologic status severity rating scores increased stepwise, with scores of 0 for N0, 1 for N1, and 2 for N2. Consistent with the Thoracolumbar AO Spine Injury Score, N3 (incomplete) and N4 (complete) injuries were given a score of 4. Finally, case-specific modifiers M1 (PLC injury) received a score of 1, while M2 (critical disc herniation) and M3 (spine stiffening disease) received a score of 4.

CONCLUSIONS

The Subaxial Cervical AO Spine Injury Score is an easy-to-use metric that can help develop a surgical algorithm to supplement the AO Spine Subaxial Cervical Spine Injury Classification System.

The effect of extracorporeal shock wave therapy in acute traumatic spinal cord injury on motor and sensory function within 6 months post-injury: a study protocol for a two-arm three-stage adaptive, prospective, multi-center, randomized, blinded, placebo-controlled clinical trial

Background

The pathological mechanism in acute spinal cord injury (SCI) is dual sequential: the primary mechanical lesion and the secondary injury due to a cascade of biochemical and pathological changes initiated by the primary lesion. Therapeutic approaches have focused on modulating the mechanisms of secondary injury. Despite extensive efforts in the treatment of SCI, there is yet no causal, curative treatment approach available.

Extracorporeal shock wave therapy (ESWT) has been successfully implemented in clinical use. Biological responses to therapeutic shock waves include altered metabolic activity of various cell types due to direct and indirect mechanotransduction leading to improved migration, proliferation, chemotaxis, modulation of the inflammatory response, angiogenesis, and neovascularization, thus inducing rather a regeneration than repair.

The aim of this clinical study is to investigate the effect of ESWT in humans within the first 48 h after an acute traumatic SCI, with the objective to intervene in the secondary injury phase in order to reduce the extent of neuronal loss.

Methods

This two-arm three-stage adaptive, prospective, multi-center, randomized, blinded, placebo-controlled study has been initiated in July 2020, and a total of 82 patients with acute traumatic SCI will be recruited for the first stage in 15 participating hospitals as part of a two-armed three-stage adaptive trial design. The focused ESWT (energy flux density: 0.1–0.19 mJ/mm², frequency: 2–5 Hz) is applied once at the level of the lesion, five segments above/below, and on the plantar surface of both feet within the first 48 h after trauma.

The degree of improvement in motor and sensory function after 6 months post-injury is the primary endpoint of the study. Secondary endpoints include routine blood chemistry parameters, the degree of spasticity, the ability to walk, urological function, quality of life, and the independence in everyday life.

Discussion

The application of ESWT activates the nervous tissue regeneration involving a multitude of various biochemical and cellular events and leads to a decreased neuronal loss. ESWT might contribute to an improvement in the treatment of acute traumatic SCI in future clinical use.

Trial registration

ClinicalTrials.govNCT04474106

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06161-8.

Minimally invasive pedicle screw fixation, including the fractured vertebra, combined with percutaneous vertebroplasty for treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals: A prospective clinical study

To evaluate the feasibility, efficacy, and safety of minimally invasive pedicle screw (MIPS) fixation, including the fractured vertebra, combined with percutaneous vertebroplasty (PVP) for the treatment of acute thoracolumbar osteoporotic compression fracture in middle-age and elderly individuals.Between January 2016 and August 2019, a total of 30 patients, with a mean age of 69.4 years (range, 58-75 years), who experienced thoracic or lumbar fracture without neurological deficits, underwent the MIPS procedure combined with PVP. Preoperative and postoperative pain were assessed using a visual analog scale and Oswestry Disability Index. Cobb angles and anterior column height were measured on lateral radiographs before surgery and at 3 days, 1, 3, and 6 months, and 1 and 2 years at final follow-up after surgery.All patients underwent surgery successfully, with a mean follow-up of 18.2 ± 5.7 months (range, 12-45 months). Mean preoperative visual analog scale score decreased from 7.3 ± 2.2 to 1.4 ± 0.3 at the final follow-up (P < .05). Mean preoperative Oswestry Disability Index decreased from 84.2 ± 10.3 to 18.8 ± 7.5 (P < .05) at the final follow-up. The Kyphosis angle of operative segment was improved from preoperative (21.38 ± 1.68)° to (4.01 ± 1.38)° 3 days postoperatively and (5.02 ± 1.09)° at final follow-up (P < .05). The anterior vertebral height was improved from preoperative (49.86 ± 6.50)% to (94.01 ± 1.79)% 3 days postoperatively and (91.80 ± 1.88)% at final follow-up (P < .05). No significant changes in vertebral body height restoration were observed during 2 years of follow-up after surgery. In addition, there were no instrumentation failures or complications in any of the patients.MIPS, including the fractured vertebra, combined with PVP, was a reliable and safe procedure, with satisfactory clinical and radiological results for the treatment of thoracolumbar osteoporotic compression fracture in patients without neurological deficits.

Long-segment fixation VS short-segment fixation combined with kyphoplasty for osteoporotic thoracolumbar burst fracture

Background

To retrospectively compare clinical and radiological results of long-segment fixation (LF) and six-screw short-segment fixation combined with kyphoplasty (SSFK) for osteoporotic thoracolumbar burst fracture (OTBF).

Methods

Forty patients affected by OTBF with mean age of 61.85 years were included in this study. The mean follow-up period was 13.63 months. Twenty-four patients were treated by SSFK, and 16 patients were treated by LF. Clinical outcomes, radiological parameters and complications were assessed and compared.

Results

The mean operative time and blood loss were 89.71 ± 7.62 min and 143.75 ± 42.51 ml for SSFK group, respectively; 111.69 ± 12.25 min (P < 0.01) and 259.38 ± 49.05 ml (P < 0.01) for LF group, respectively. The two groups were similar in terms of preoperative radiological and clinical results. Compared with preoperative values, both groups achieved significant improvement in terms of VAS, ODI, Cobb angle and anterior vertebral body height (AVH) ratio at final follow-up. However, during the follow-up period, significant loss of Cobb angle and AVH ratio were observed for both groups. Five cases (20.83%) of asymptomatic cement leakage were observed in SSFK group. One case of implant failure and two cases of adjacent or non-adjacent vertebral fractures were observed in LF group.

Conclusions

Both SSFK and LF are safe and effective for treatment of OTBF. Comparatively, SSFK is less invasive and can preserve more motion segments, which may be a more valuable surgical option in some elderly patients. A high-quality randomized controlled study is required to confirm our finding in the future.

The impact of surgical timing on motor level lowering in motor complete traumatic spinal cord injury patients

Patients with motor complete traumatic spinal cord injury (tSCI) have a low potential to recover ambulation. Motor level recovery, adjacent to the level of injury, could influence functional independency. This study addresses whether surgical timing influences motor level recovery in patients with sensorimotor complete (AIS A) and motor complete sensory incomplete (AIS B) tSCI. A retrospective cohort study was performed in the Netherlands in patients with motor complete tSCI (C2-L2), who consecutively underwent surgery between January 2010 and April 2020. Neurological examination was performed directly at presentation to the ER and at discharge from the rehabilitation facility. Motor level lowering, AIS grade and Upper and Lower Extremity Motor Score (UEMS and LEMS) recovery were calculated for patients who underwent early (<24h) and late (24h+) surgery. A total of 96 patients met the inclusion criteria. In the multivariate analysis late surgical decompression (24h+) was negatively associated with ≥1 motor level lowering and ≥2 AIS grade improvement (Odds Ratio (OR) 0.11 (95% CI: 0.01, 0.67) p=0.046, OR 0.06 (95% CI: 0.00, 047) p=0.030). The presence of sacral sparing (AIS B) at initial examination, and cervical level of the tSCI were associated with ≥1 motor level lowering. In addition, AOSpine C-type injuries were negatively associated with any type of neurological recovery, except motor level lowering. Although sensorimotor complete injuries as well as thoracolumbar injuries negatively influence neurological recovery, early surgical decompression (<24h) appears independently associated with enhanced neurological recovery in patients with traumatic spinal cord injury despite level and severity of injury.

Monitoring spinal surgery for extramedullary tumors and fractures

Meningiomas are the most common intradural extramedullary tumors, followed by nerve sheath tumors that can also grow extradurally. Metastases are the most frequent extradural tumors and most commonly affect the thoracic vertebrae. Spinal fractures with column dislocation and/or instability require surgical fixation. Spine surgery for an extramedullary tumor or fracture usually involves decompression of neural elements and instrumentation for stabilization. These procedures risk spinal cord and nerve root injury. The incidence of nerve root deficits after resection of nerve sheath tumors is particularly high since the tumor grows from the rootlets. Intraoperative neurophysiologic monitoring and mapping techniques have been introduced to prevent iatrogenic neurologic deficits. These include motor and sensory evoked potentials, electromyography, compound muscle action potentials, and the bulbocavernosus reflex. The combination of techniques chosen for a particular procedure depends on the surgical level and the character of the lesion.

Which traumatic spinal injury creates which degree of instability? A systematic quantitative review

BACKGROUND CONTEXT

Traumatic spinal injuries often require surgical fixation. Specific three-dimensional degrees of instability after spinal injury, which represent criteria for optimum treatment concepts, however, are still not well investigated.

PURPOSE

The aim of this review therefore was to summarize and quantify multiplanar instability increases due to spinal injury from experimental studies.

STUDY DESIGN/SETTING

Systematic review.

METHODS

A systematic review of the literature was performed using keyword-based search on PubMed and Web of Science databases in order to detect all in vitro studies investigating the destabilizing effect of simulated and provoked traumatic injury in human spine specimens. Together with the experimental designs, the instability parameters range of motion, neutral zone and translation were extracted from the studies and evaluated regarding type and level of injury.

RESULTS

A total of 59 studies was included in this review, of which 43 studies investigated the effect of cervical spine injury. Range of motion increase, which was reported in 58 studies, was generally lower compared to the neutral zone increase, given in 37 studies, despite of injury type and level. Instability increases were highest in flexion/extension for most injury types, while axial rotation was predominantly affected after cervical unilateral dislocation injury and lateral bending solely after odontoid fracture. Whiplash injuries and wedge fractures were found to increase instability equally in all motion planes.

CONCLUSIONS

Specific traumatic spinal injuries produce characteristic but complex three-dimensional degrees of instability, which depend on the type, level, and morphology of the injury. Future studies should expand research on the cervicothoracic, thoracic, and lumbosacral spine and should additionally investigate the destabilizing effects of the injury morphology as well as concomitant rib cage injuries in case of thoracic spinal injuries. Moreover, neutral zone and translation should be measured in addition to the range of motion, while mechanical injury simulation should be preferred to resection or transection of structures to ensure high comparability with the clinical situation.

Vertebroplasty, Kyphoplasty, and Implant-Based Mechanical Vertebral Augmentation

Vertebral compression fractures are a global public health issue with a quantifiable negative impact on patient morbidity and mortality. The contemporary approach to the treatment of osteoporotic fragility fractures has moved beyond first-line nonsurgical management. An improved understanding of biomechanical forces, consequential morbidity and mortality, and the drive to reduce opioid use has resulted in multidisciplinary treatment algorithms and significant advances in augmentation techniques. This review will inform musculoskeletal radiologists, interventionalists, and minimally invasive spine surgeons on the proper work-up of patients, imaging features differentiating benign and malignant pathologic fractures, high-risk fracture morphologies, and new mechanical augmentation device options, and it describes the appropriate selection of devices, complications, outcomes, and future trends.

Validation of the AO Spine Sacral Classification System: Reliability Among Surgeons Worldwide

OBJECTIVES

To (1) demonstrate that the AO Spine Sacral Classification System can be reliably applied by general orthopaedic surgeons and subspecialists universally around the world and (2) delineate those injury subtypes that are most difficult to classify reliably to refine the classification before evaluating clinical outcomes.

DESIGN

Agreement study.

SETTING

All-level trauma centers, worldwide.

PARTICIPANTS

One hundred seventy-two members of the AO Trauma and AO Spine community.

INTERVENTION

The AO Sacral Classification System was applied by each surgeon to 26 cases in 2 independent assessments performed 3 weeks apart.

MAIN OUTCOME MEASUREMENTS

Interobserver reliability and intraobserver reproducibility.

RESULTS

A total of 8097 case assessments were performed. The kappa coefficient for interobserver agreement for all cases was 0.72/0.75 (assessment 1/assessment 2), representing substantial reliability. When comparing classification grading (A/B/C) regardless of subtype, the kappa coefficient was 0.84/0.85, corresponding to excellent reliability. The kappa coefficients for interobserver reliability were 0.95/0.93 for type A fractures, 0.78/0.79 for type B fractures, and 0.80/0.83 for type C fractures. The overall kappa statistic for intraobserver reliability was 0.82 (range 0.18-1.00), representing excellent reproducibility. When only evaluating morphology type (A/B/C), the average kappa value was 0.87 (range 0.18-1.00), representing excellent reproducibility.

CONCLUSION

The AO Spine Sacral Classification System is universally reliable among general orthopaedic surgeons and subspecialists worldwide, with substantial interobserver and excellent intraobserver reliability.

PERCUTANEOUS INSTRUMENTATION WITHOUT ARTHRODESIS FOR THORACOLUMBAR BURST FRACTURES (A3/A4, B): A RETROSPECTIVE STUDY

ABSTRACT Objective: There is still no consensus as to the treatment options for thoracolumbar burst fractures, although these fractures are widely described in the literature. The aim of this study was to evaluate the clinical and radiological outcomes of percutaneous instrumentation without arthrodesis as a method of fixation of these lesions. Methods: This retrospective, cross-sectional study evaluated 16 patients by measuring regional kyphosis using the Cobb method and the scores for quality of life and return to work (Oswestry Disability Index, VAS, SF-36 and Denis). Results: Six months after surgical treatment, 62.5% of all patients showed minimal disability according to the Oswestry Disability Index, maintenance of regional kyphosis correction and no synthesis failure. Conclusions: The clinical and radiological outcomes of the study suggest that minimally invasive fixation is indicated for the treatment of thoracolumbar burst fractures. Level of evidence IV; Observational study: retrospective cohort.

Posterior Ligamentous Complex Injuries of the Thoracolumbar Spine: Importance and Surgical Implications

The soft tissues surrounding the spine play a primordial role in its stability, the most important of which are located posteriorly and are deemed the posterior ligamentous complex (PLC). Injuries to the PLC in the setting of thoracolumbar trauma are often dreaded and little attention has been given to them in the management protocols of thoracolumbar trauma. This review aims to summarize and contextualize current concepts in PLC injuries of the thoracolumbar spine with the aim to provide a clear guide for clinical management.

Injuries to the PLC may be suspected on the clinical exam but are often missed, leading to serious complications, including instability and neurological compromise. The diagnosis is often made indirectly by spinal radiographs and CT-scanning or by direct visualization of soft tissues via magnetic resonance imaging. The latter remains the standard imaging modality and is mandatory for patients with a high suspicion of PLC injury. PLC injuries are associated with vertebral fractures and follow a progressive pattern of severity, depending on the mechanism of injury and extent of trauma. Surgical management is warranted, as PLC damage renders the spine unstable. Although fusion was once the standard of care and remains applicable for certain patients, recent endeavors of temporary spinal fixation without fusion are increasingly gaining traction in patients with PLC injuries.

In conclusion, PLC injuries are challenging as they are often missed, poorly understood, and are not easily managed. Proper diagnosis and management are crucial to avoid long-standing complications such as spinal instability. Considering the paucity of available data on such an important topic in thoracolumbar trauma, this review article aims to contextualize current concepts in PLC injuries in order to demystify this sparsely covered subject.

Minimally invasive corpectomy and percutaneous transpedicular stabilization in the treatment of patients with unstable injures of the thoracolumbar spine: Results of retrospective case series

Objective:

The objective of this study was to analyze the results of surgical treatment of patients with unstable injuries of the thoracolumbar spine using simultaneous minimally invasive corpectomy and percutaneous transpedicular stabilization.

Materials and Methods:

The retrospective study included 34 patients with isolated single-level unstable injuries of the thoracolumbar spine (5 or more points according to the Thoracolumbar Injury Classification and Severity Score (TLICS), operated on from the moment of injury from 8 to 24 h using the technique of minimally invasive corpectomy and percutaneous transpedicular stabilization simultaneously. The technical features of surgery, clinical data (pain level according to the Visual Analog Scale, quality of life according to the SF-36 questionnaire, subjective satisfaction with the operation according to the MacNab scale, and the presence of complications), and instrumental data (angle of segmental kyphotic deformity and sagittal index to and after surgery). The assessment of clinical data was carried out before surgery, at discharge, after 6 months, and in the long-term period, on average, 30 months after surgery.

Results:

When evaluating the clinical data, a significant decrease in the severity of pain syndrome was found on average from 90 mm to 5.5 mm in the late follow-up (P < 0.001), as well as a significant improvement in the physical and psychological components of health according to the SF-36 questionnaire on average from 28.78 to 39.26 (P < 0.001), from 36.93 to 41.43 (P = 0.006), respectively. In the long-term period, according to the MacNab scale, the patients noted the result of the operation: excellent – 18 (52.9%), good – 13 (38.3%), and satisfactory – 3 (8.8%); no unsatisfactory results were registered. Four (11.8%) perioperative surgical complications were registered, which were successfully treated conservatively. A significant restoration of the sagittal profile with an insignificant change in blood pressure was recorded in the long-term postoperative period. An average follow-up assessment of 30 months according to the American Spinal Injury Association scale showed the presence of E and D degrees in 85.4% of patients.

Conclusion:

Minimally invasive corpectomy with percutaneous transpedicular stabilization in the treatment of patients with unstable injuries of the thoracolumbar spine can effectively eliminate kyphotic deformity and prevent the loss of its reduction with a low number of postoperative surgical complications. The technique has minimal surgical trauma with the possibility of early postoperative rehabilitation and provides a significant stable reduction in vertebrogenic pain syndrome, improvement of neurological deficits, and restoration of the quality of life of patients and in the follow-up.

A multilevel noncontiguous spinal fracture with cervical and thoracic spinal cord injury

INTRODUCTION AND IMPORTANCE

A multi-level non-contiguous spinal fracture (MNSF) caused by a high-energy impact is a type of complex traumatic injury that is been frequently initially missed, and resulting in delayed diagnosis which adversely affects can result in spinal deformity and neurological deficit. This report describes the operative management of a patient with MNSF with spinal cord injury involving the cervical and thoracic vertebrae by cervical orthosis and posterior thoracic decompression and fusion.

CASE PRESENTATION

An 18-year-old male presented with extensive neck pain and paraplegia (ASIA A), following a motor vehicle accident. Radiographic imaging revealed MNSF: a non-displaced spinous process fracture of C5 (AO Spine subaxial cervical injury classification A0) with spinal cord injury combined with fracture-dislocation of T5 to T9 (AO Spine thoracolumbar injury classification C3). Posterior thoracic decompression and fusion was performed at T3 to T8. After the patient underwent the thoracic spine and cervical orthosis treatment, He received rehabilitation program and training transfer with wheelchair without caregiver. His sitting and balance were significantly improved at the 6 months follow-up. Although the lower extremity functions (ASIA A) may not improve due to the severe spinal cord injury.

CLINICAL DISCUSSION

MNSF with spinal cord injury following a high-velocity accident is an unstable and complex injury. Important of the clinical assessment and according to the injuries the treatment may vary.

CONCLUSIONS

Cervical orthosis was alternative treatment to preserve cervical motion treatment and posterior thoracic decompression with fixation is an effective option for patients in this MNSF with spinal cord injury.

Development and validation of a simplified thoracolumbar spine fracture classification system

STUDY DESIGN

Development and validation of fracture classification system.

OBJECTIVE

To develop and validate a Simplified Classification System (SCS) for Thoraco-Lumbar (TL) fractures (SCS - TL fractures).

SETTING

Tertiary Spinal Injuries Centre, New Delhi, India METHODS: Based on the International Spinal Cord Society Spine Trauma Study Group (ISCoS STSG, n = 23) experts' clinical consensus conducted by the senior author and on his own experience, the Denis classification for TL fractures was modified to develop a SCS-TL fractures that could guide the management. After Face and Content validation, Construct validation was done in two stages. First stage analyzed if management of 30 cases of TL fractures, as suggested by the SCS - TL fractures and ISCoS STSG (n = 9) as well as other (n = 5) experts, matched. Second stage was a one year prospective study analyzing if the management suggested matched the management actually carried out by different spine surgeons (n = 10) working at a single institution.

RESULTS

In the first stage there was 100% agreement for management (conservative or surgical) as proposed by experts and that suggested by the proposed classification for TL fractures whereas for surgical approach there was 88% agreement. In the second stage, there was 100% agreement for the management as well as surgical approach as carried out at our centre and that proposed by the SCS for TL fractures.

CONCLUSIONS

The proposed SCS-TL fractures helps in classifying and in decision making for management of TL fractures. The next phase of validation would involve multicentric reliability studies and prospective application of the SCS- TL fractures.

Lag-Screw Osteosynthesis in Thoracolumbar Pincer Fractures

STUDY DESIGN

Biomechanical.

OBJECTIVE

This study evaluates the biomechanical properties of lag-screws used in vertebral pincer fractures at the thoracolumbar junction.

METHODS

Pincer fractures were created in 18 bisegmental human specimens. The specimens were assigned to three groups depending on their treatment perspective, either bolted, with the thread positioned in the cortical or cancellous bone, or control. The specimens were mounted in a servo-hydraulic testing machine and loaded with a 500 N follower load. They were consecutively tested in 3 different conditions: intact, fractured, and bolted/control. For each condition 10 cycles in extension/flexion, torsion, and lateral bending were applied. After each tested condition, a computed tomography (CT) scan was performed. Finally, an extension/flexion fatigue loading was applied to all specimens.

RESULTS

Biomechanical results revealed a nonsignificant increase in stiffness in extension/flexion of the fractured specimens compared with the intact ones. For lateral bending and torsion, the stiffness was significantly lower. Compared with the fractured specimens, no changes in stiffness due to bolting were discovered. CT scans showed an increasing fracture gap during axial loading both in extension/flexion, torsion, and lateral bending in the control specimens. In bolted specimens, the anterior fragment was approximated, and the fracture gap nullified. This refers to both the cortical and the cancellous thread positions.

CONCLUSION

The results of this study concerning the effect of lag-screws on pincer fractures appear promising. Though there was little effect on stiffness, CT scans reveal a bony contact in the bolted specimens, which is a requirement for bony healing.

Minimally Invasive Versus Open Surgery for the Treatment of Types B and C Thoracolumbar Injuries: A PRISMA Systematic Review

BACKGROUND

Thoracic and lumbar spine injuries may require surgical management, particularly AO Spine types B and C injuries. Open reduction and fixation using pedicle screws, with or without fusion and/or decompression, is the gold standard surgical treatment for unstable injuries. Recent advances in instrumentation design have resulted in less-invasive surgeries. However, the literature is sparse about the effectiveness of these procedures for types B and C injuries. The objective is to compare the outcomes of conventional open surgery versus minimally invasive spine surgery (MISS) for the treatment of AO Spine types B and C thoracolumbar injuries.

METHODS

A systematic review of published literature in PubMed, Web of Science, and Scopus was performed to identify studies comparing outcomes achieved with open versus minimally invasive surgery in AO Spine types B and C thoracolumbar injury patients. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used.

RESULTS

Five retrospective case-control studies and 3 prospective studies met selection criteria. In general, most of the studies demonstrated that minimally invasive spine surgery is feasible for types B and C injuries, and associated with potential advantages like reduced blood loss, postoperative pain, and muscle injury, and shorter hospital stays. However, no differences were detected in major outcomes, like neurological status or disability.

CONCLUSIONS

Published literature currently suggests that minimally invasive spine surgery is a valid alternative for treating types B and C thoracolumbar injuries. However, further comparative prospective randomized clinical trials are necessary to establish the superiority of one approach over the other.

LEVEL OF EVIDENCE

3.

[Three-dimensional printed drill guide template assisting percutaneous pedicle screw fixation for multiple-level thoracolumbar fractures]

Objective

To evaluate the feasibility and safety of three-dimensional (3D) printed drill guide template-assisted percutaneous pedicle screw fixation for multiple-level thoracolumbar fractures.

Methods

Clinical data of 19 patients with multilevel thoracolumbar fracture without nerve injury who underwent surgical treatment between May 2017 and January 2019 were retrospectively analyzed. There were 9 males and 10 females and their age ranged from 22 to 63 years, with an average age of 43.6 years. Injury cause included traffic accident injury in 12 cases, and fall from height injury in 7 cases. A total of 40 fractured vertebrae were involved in T ₁₀ to L ₃ levels. According to AO classification, there were 29 fractures of type A1, 9 fractures of type A2, and 2 fractures of type A3. According to TANG Sanyuan classification, multiple-segment thoracolumbar fractures were classified as 17 cases of type ⅠA, 1 case of type ⅠB, and 1 case of type ⅡC. The time from injury to operation was 2-6 days, with an average of 3.1 days. The 3D-printed universal drill guide template was used for assisting percutaneous pedicle screw fixation during operation. Intraoperative blood loss, average operation time and fluoroscopy frequency of each screw were recorded. Visual analogue scale (VAS) score was used to evaluate the improvement of low back pain before operation, at 3 days after operation, and at last follow-up. According to the CT at 3 days after operation, the Gertzbein and Robbins scales were used to evaluate the accuracy of screw insertion (the grade A and grade B were regarded as accuracy, the grade A was regarded as excellent of screw insertion). The Cobb angle in sagittal plane of the fracture segment was measured, and the percentage of anterior edge of injured vertebral height was calculated. The consistency of the inclination of bilateral pedicle screws were analyzed postoperatively, and compared the angle of the intraoperative guide plate with the inclination of screw to verify the effectiveness of the guide plate in controlling the inclination.

Results

All the 19 patients completed the operation successfully, and the intraoperative blood loss was 44-67 mL, with an average of 54.3 mL. The average operation time for each screw insertion was 7.3-11.1 minutes, with an average of 9.6 minutes. The average fluoroscopy frequency of each screw insertion was 1.6-2.5 times, with an average of 2.0 times. No spinal cord, nerve root injury, infection, and other complications occurred. All patients were followed up 24-38 months, with an average of 28.7 months. The accuracy of pedicle screws was evaluated by using Gertzbein and Robbins scales: 145 screws were grade A and 11 screws were grade B. The accuracy of screw insertion was 100% and the excellent rate was 92.9%. The CT data at 3 days after operation showed no significant difference in the inclination between the left and right screws in the same vertebral body ( t=0.93, P=0.36). There was no significant difference between the angle of guide plate and the screw inclination ( P>0.05). The VAS score, Cobb angle in sagittal plane, and the percentage of anterior edge of injured vertebral height were significantly improved at 3 days after operation and at last follow-up, and the VAS score was declined at last follow-up compared with 3 days after operation, all showing significant differences ( P<0.05). There was no significant difference in the sagittal Cobb angle and the percentage of anterior edge of injured vertebral height between two postoperative time points ( P>0.05). At last follow-up, no internal fixators were loosened or broken, and all fractures healed well.

Conclusion

For the multiple-level thoracolumbar fractures, 3D-printed drill guide template assisting percutaneous pedicle screw fixation can reduce the operation time, intraoperative blood loss, and fluoroscopy frequency and the screw insertion is accurate and has a good reduction effect.

Variation in global treatment for subaxial cervical spine isolated unilateral facet fractures

PURPOSE

To determine the variation in the global treatment practices for subaxial unilateral cervical spine facet fractures based on surgeon experience, practice setting, and surgical subspecialty.

METHODS

A survey was sent to 272 members of the AO Spine Subaxial Injury Classification System Validation Group worldwide. Questions surveyed surgeon preferences with regard to diagnostic work-up and treatment of fracture types F1-F3, according to the AO Spine Subaxial Cervical Spine Injury Classification System, with various associated neurologic injuries.

RESULTS

A total of 161 responses were received. Academic surgeons use the facet portion of the AO Spine classification system less frequently (61.6%) compared to hospital-employed and private practice surgeons (81.1% and 81.8%, respectively) (p = 0.029). The overall consensus was in favor of operative treatment for any facet fracture with radicular symptoms (N2) and for any fractures categorized as F2N2 and above. For F3N0 fractures, significantly less surgeons from Africa/Asia/Middle East (49%) and Europe (59.2%) chose operative treatment than from North/Latin/South America (74.1%) (p = 0.025). For F3N1 fractures, significantly less surgeons from Africa/Asia/Middle East (52%) and Europe (63.3%) recommended operative treatment than from North/Latin/South America (84.5%) (p = 0.001). More than 95% of surgeons included CT in their work-up of facet fractures, regardless of the type. No statistically significant differences were seen in the need for MRI to decide treatment.

CONCLUSION

Considerable agreement exists between surgeon preferences with regard to unilateral facet fracture management with few exceptions. F2N2 fracture subtypes and subtypes with radiculopathy (N2) appear to be the threshold for operative treatment.

Establishing the Injury Severity of Subaxial Cervical Spine Trauma: Validating the Hierarchical Nature of the AO Spine Subaxial Cervical Spine Injury Classification System

STUDY DESIGN

Global cross-sectional survey.

OBJECTIVE

The aim of this study was to validate the AO Spine Subaxial Cervical Spine Injury Classification by examining the perceived injury severity by surgeon across AO geographical regions and practice experience.

SUMMARY OF BACKGROUND DATA

Previous subaxial cervical spine injury classifications have been limited by subpar interobserver reliability and clinical applicability. In an attempt to create a universally validated scheme with prognostic value, AO Spine established a subaxial cervical spine injury classification involving four elements: injury morphology, facet injury involvement, neurologic status, and case-specific modifiers.

METHODS

A survey was sent to 272 AO Spine members across all geographic regions and with a variety of practice experience. Respondents graded the severity of each variable of the classification system on a scale from zero (low severity) to 100 (high severity). Primary outcome was to assess differences in perceived injury severity for each injury type over geographic regions and level of practice experience.

RESULTS

A total of 189 responses were received. Overall, the classification system exhibited a hierarchical progression in subtype injury severity scores. Only three subtypes showed a significant difference in injury severity score among geographic regions: F3 (floating lateral mass fracture, P = 0.04), N3 (incomplete spinal cord injury, P = 0.03), and M2 (critical disk herniation, P = 0.04). When stratified by surgeon experience, pairwise comparison showed only two morphological subtypes, B1 (bony posterior tension band injury, P = 0.02) and F2 (unstable facet fracture, P = 0.03), and one neurologic subtype (N3, P = 0.02) exhibited a significant difference in injury severity score.

CONCLUSION

The AO Spine Subaxial Cervical Spine Injury Classification System has shown to be reliable and suitable for proper patient management. The study shows this classification is substantially generalizable by geographic region and surgeon experience, and provides a consistent method of communication among physicians while covering the majority of subaxial cervical spine traumatic injuries.Level of Evidence: 4.

New Grading System for Cervical Paraspinal Soft Tissue Damage After Traumatic Cervical Spinal Cord Injury Without Major Fracture Based on the Short-T1 Inversion Recovery Mid-Sagittal MRI for Prediction of Neurological Improvements: The STIR-MRI Grade

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To develop a grading method for cervical paraspinal soft tissue damage after cervical spinal cord injury (CSCI) without major fracture based on the short T1 inversion recovery (STIR) mid-sagittal magnetic resonance image (MRI) for prediction of neurological improvements.

METHODS

This study included 34 patients with CSCI without major fracture, treated conservatively for at least 1 year and graded using the STIR-MRI Grade. This system consists of anterior grades; A0: no high-intensity area (HIA), A1: linear HIA, and A2: fusiform HIA, and posterior grades; P0: no HIA, P1: HIA not exceeding the nuchal ligament, and P2: HIA exceeding the nuchal ligament, within 24 hours postinjury. The American Spinal Injury Association impairment scale (AIS) and the Japanese Orthopedic Association (JOA) scores were examined.

RESULTS

Anterior grades were not significantly correlated with the AIS and JOA score. At both injury and final follow-up, the AIS in P2 patients was significantly more severe (P = 0.007, P = 0.015, respectively) than that in P0 patients. At the injury, the AIS in P2 patients was significantly more severe (P = 0.008) than that in P1 patients. Among P2 patients only, the JOA score at the injury (1.4 points) did not improve by the final follow-up (3.9 points). The final follow-up JOA score (3.9 points) in P2 patients was significantly lower than that (13.6 points) in P0 patients (P = 0.016).

CONCLUSIONS

Grade P2 led to poor neurological outcomes. The STIR-MRI Grade is a prognostic indicator for neurological improvements past-CSCI.

Accuracy and reliability of the AO Spine subaxial cervical spine classification system grading subaxial cervical facet injury morphology

PURPOSE

A classification system was recently developed by the international association AO Spine for assessing subaxial cervical spine fractures. Significant variability exists between users of the facet component, which consists of four morphological types (F1-F4). The primary aims of this study were to assess the diagnostic accuracy and reliability of this new system's facet injury morphological classifications.

METHODS

A survey consisting of 16 computed tomography (CT) scans of patients with cervical facet fractures was distributed to spine surgeon members of AO Spine Latin America. To provide a gold standard diagnosis for comparison, all 16 injuries had been classified previously by six co-authors and only were included after total consensus was achieved. Demographic and surgical practice characteristics of all respondents were analyzed, and diagnostic accuracy calculated. Inter- and intra-observer agreement rates were calculated across two survey rounds, conducted one month apart.

RESULTS

A total of 135 surgeons completed both surveys, among whom the mean age was 41.6 years (range 26-71), 130 (96.3%) were men, and 83 (61.5%) were orthopedic surgeons. The mean time in practice as a spine surgeon was 9.7 years (1-30). The overall diagnostic accuracy of all responses was 65.4%. Inter-observer and intra-observer agreement rates for F1/F2/F3/F4 were 55.4%/47.6%/64.0%/94.7% and 60.0%/49.1%/58.0%/93.0%, respectively.

CONCLUSION

This study evaluates the AO Spine Classification System specifically for facet injuries involving the subaxial cervical spine in a large sample of spine surgeons. There was significant variability in diagnostic accuracy for F1 through F3-type fractures, whereas almost universal agreement was achieved for F4-type injuries.

Early loss of angular kyphosis correction in patients with thoracolumbar vertebral burst (A3-A4) fractures who underwent percutaneous pedicle screws fixation

Purpose

Percutaneous trans-pedicle screws represent a surgical option frequently performed in patients affected by thoracolumbar vertebral burst fractures (A3-A4). The aim of the study was to evaluate the early loss of kyphosis correction and its clinical correlations in a cohort of patients affected by burst spinal fracture treated with percutaneous trans-pedicle screws fixation.

Methods

The present investigation consists in a retrospective one center analysis. The primary outcome was the evaluation of the early loss of correction. Secondary outcomes were the bi-segmental kyphosis change, the clinical outcome and the correlation between clinical outcome and the loss of correction.

Results

Among 435 patients 97 were included in the study. A mean 3.3° of early loss of correction was observed between postoperative and 1 month follow-up evaluations. The mean anterior vertebral body height change was 3.8 mm. No statistical differences were found in clinical and functional outcomes between patients with >2° or <2° of kyphosis loss of correction.

Conclusion

No statistical differences were found between 1 e 6 months postoperative kyphosis loss of correction. The amount of loss of correction seems not to influence clinical outcomes after percutaneous trans-pedicle screw fixation in patients with vertebral burst fractures.

Epidemiology of Traumatic Spinal Cord Injury in the Netherlands: Emergency Medical Service, Hospital, and Functional Outcomes

Background

Evaluating treatment of traumatic spinal cord injuries (TSCIs) from the prehospital phase until postrehabilitation is crucial to improve outcomes of future TSCI patients.

Objective

To describe the flow of patients with TSCI through the prehospital, hospital, and rehabilitation settings and to relate treatment outcomes to emergency medical services (EMS) transport locations and surgery timing.

Method

Consecutive TSCI admissions to a level I trauma center (L1TC) in the Netherlands between 2015 and 2018 were retrospectively identified. Corresponding EMS, hospital, and rehabilitation records were assessed.

Results

A total of 151 patients were included. Their median age was 58 (IQR 37-72) years, with the majority being male (68%) and suffering from cervical spine injuries (75%). In total, 66.2% of the patients with TSCI symptoms were transported directly to an L1TC, and 30.5% were secondarily transferred in from a lower level trauma center. Most injuries were due to falls (63.0%) and traffic accidents (31.1%), mainly bicycle-related. Most patients showed stable vital signs in the ambulance and the emergency department. After hospital discharge, 71 (47.0%) patients were admitted to a rehabilitation hospital, and 34 (22.5%) patients went home. The 30-day mortality rate was 13%. Patients receiving acute surgery (<12 hours) compared to subacute surgery (>12h, <2 weeks) showed no significance in functional independence scores after rehabilitation treatment.

Conclusion

A surge in age and bicycle-injuries in TSCI patients was observed. A substantial number of patients with TSCI were undertriaged. Acute surgery (<12 hours) showed comparable outcomes results in subacute surgery (>12h, <2 weeks) patients.

Subaxial Cervical Spine Injuries: WFNS Spine Committee Recommendations

To formulate specific guidelines for the recommendation of subaxial cervical spine injuries concerning classification, management, posttraumatic locked facets and vertebral artery injury. Computerized literature was searched on PubMed and google scholar database from 2009 to 2020. For classification, keywords “Sub Axial Cervical Spine Classification,” resulting in 22 articles related to subaxial cervical spine injury classification system (SLICS) system and 11 articles related to AO (Arbeitsgemeinschaft für Osteosynthesefragen, German for “Association for the Study of Internal Fixation”) Spine system. The literature search yielded 210 and 78 articles on “management of subaxial cervical spine injuries” and the role of “SLICS” and “AO Spine” respectively. Keywords “management of traumatic facet locks” were searched and closed reduction, traction, approaches and techniques were studied. “Vertebral artery injury and cervical fracture” exhibited 2,328 references from the last 15 years. The objective was to identify the appropriate diagnostic tests and optimal treatment. Up-to-date information was reviewed, and statements were produced to reach a consensus in 2 separate consensus meetings of World Federation of Neurosurgical Societies (WFNS) Spine Committee. The statements were voted and reached a positive or negative consensus using Delphi method. Based on the most relevant literature, panelists in Moscow consensus meeting conducted in May 2019 drafted the statements, and after a preliminary voting session, the consensus was identified on various statements. Another meeting was conducted at Peshawar in November 2019, where in addition to previous statements, few other statements were discussed and voted. Specific recommendations were then formulated guiding classification, management, locked facets and vertebral artery injuries. This review summarizes the WFNS Spine Committee recommendations on subaxial cervical spine injuries.