Traumatic injuries of the spinal column represent only a minority of all fractures, with a reported incidence of 4%–23% in various epidemiological studies.1 However, their influence on individuals' social, functional, and financial situation is more significant than other injuries, as they may contribute to disability with long-term consequences and associated health-related costs. Management of spine injuries has continued to be a source of considerable contention within the overall field of musculoskeletal traumatology. Continued efforts have concentrated on refining more traditional spine trauma classification systems with a focus at providing simpler and more reproducible diagnostic and therapeutic algorithms. Spine surgical techniques have also undergone various refinements in regards to approach options and implant performance.
Despite these advances, it has been challenging to apply the fundamental principles of musculoskeletal trauma care to spine trauma. There are several factors, which set spine trauma apart from other areas of musculoskeletal trauma. Firstly, the perspectives of spinal cord and cauda equina injury with its threat of irreversible neural tissue damage have a profound effect on patient outcomes and consequently may alter management. Serious spinal injuries are also commonly associated with polytrauma and often coincident with life-threatening thoracic and abdominal injuries. These factors render decision-making complex and raise questions about the preferred treatment algorithm. For patients without neurologic injury or multiple concurrent traumas, the decision-making between nonoperative management and surgical care is far from settled. Especially for injury patterns where progressive deformity or secondary neurologic deterioration is unlikely, the question remains if surgical intervention contributes to an improved quality of life. Because of the high incidence of back and neck pain among adult populations all around the world, it is difficult to differentiate posttraumatic spine conditions from dysfunction brought on by nonspecific degenerative spinal disorders.2 Furthermore, our globally aging population with its concurrent comorbidities has brought an increased incidence of geriatric spine injuries and previously rare forms of spine fractures. Lastly, when one decides on the treatment plan, different choices consist for either nonsurgical or surgical management. In case of surgical approaches and fixation techniques, surgical invasiveness of the approach and implant technology provides another variable that has traditionally not been factored into the decision-making process regarding surgical versus nonsurgical care.
In summary, there are 6 areas of persistent substantial controversy regarding the management of spine trauma:
- The role and timing of medical and surgical interventions for patients with associated neurologic injury;
- Type and timing of surgical stabilization for multiply injured patients;
- The role of nonsurgical versus surgical treatment;
- The role of different surgical approaches and techniques;
- Methods of nonoperative management;
- Care of elderly patients with concurrent complex disorders.
The Role and Timing of Medical and Surgical Interventions in Patients With Neurologic Injury
Spinal cord or cauda equina injury remains a feared consequence of spine trauma. Although management of these cases has undergone fundamental changes over the last 3 decades, controversies remain. There is some evidence pointing to a steady improvement of the general prognosis of recovery from traumatic neurologic injury. Much of this trend can probably be attributed to improvements in the initial stabilization and resuscitation protocols applied to trauma victims.3
Pharmacological interventions that prevent apoptosis and neuronal injury hold the potential to diminish propagation of the secondary zone of injury. In clinical reality, however, several large-scale prospectively randomized trials have questioned a beneficial effect of steroids on the outcome of acute traumatic spinal cord injuries. Timing of surgical intervention for spine remains another eminent source of controversy. The traditional premise that early surgical intervention may be detrimental for neurologic recovery has been firmly refuted.4 The question remains if early surgical intervention actually improves chances for neurologic recovery. The next article in this focus issue reviews the current controversies surrounding neurologic injury management associated with spinal trauma.
Type and Timing of Surgical Stabilization for Multiply Injured Patients
According to a study using the German Trauma Registry, approximately 36% of all polytrauma patients have associated spine injuries.5 This is particularly common after blunt torso trauma with associated spinal fractures with its association of subsequent pulmonary deterioration and respiratory distress and increased morbidity and mortality. The question of timing of surgical intervention in treating spine fractures in polytrauma patients remains unresolved to the present date. The life-threatening circumstances and highly variable circumstances of multiply injured patients make randomized trials regarding this question difficult if not outright impossible. Bellabarba et al6 concluded in their 2010 systematic review that patients with unstable thoracic fractures are preferably treated with early (defined as less than 72 hours) spine surgery. Similarly, Carreon and Dimar in a 2011 systematic review found that early surgical spine stabilization lead to shorter hospital stays, shorter intensive care unit stays, less days on mechanical ventilation, and lower pulmonary complications.7 This effect was more prominent in cases with a higher ISS (Injury Severity Score). Furthermore, they found some evidence showing that the complication risk was not increased in patients receiving early stabilization. In a similar review limited to thoracolumbar fractures, Xing et al also concluded that early stabilization reduced the length of stay, intensive care unit stay, ventilator days, morbidity, and hospital expenses when surgery was performed less than 72 hours after the index trauma.8 Taking early intervention concept further, a prospective study applied the “damage control” principles to spine trauma and showed that such a protocol is a safe and efficient treatment strategy.9 However, 2 recent studies showed that in certain subgroups of multiply injured patients, early surgical intervention may become a “second hit” and push patients over the edge. In a prospective study from a German trauma center, Konieczny et al10 showed that in cases with thoracic trauma and a low initial hemoglobin count, early surgical intervention may lead to higher mortality. Similarly, Galvin et al reported on the polytrauma patients with spine injuries treated at US military hospitals in conjunction with the Iraqi and Afghan conflicts. They concluded that in a borderline unstable patient, spine surgery may be associated with increased mortality.11
At this time, the question if all multiply injured patients with concurrent spine trauma benefit from early intervention or some subgroups should be deferred for medical reasons is not resolved. Currently available studies have not yet used less invasive stabilization techniques, which have become increasingly available in the more recent past. Such less invasive surgical techniques may affect the balance between the benefits of spinal stabilization and the risks of surgical “second hit” in these often critically ill patients.
The Role of Nonsurgical Versus Surgical Treatment
There is a widespread general consensus on the need for surgical intervention for patients with spinal cord injury or overt mechanical instability (AOSpine type B and C injuries).12 There is also consensus that relatively minor injuries like the AOSpine type A0 and A1 fractures in the subaxial cervical and thoracolumbar spine do not need surgical intervention. However, there are 2 spine injuries that continue to be fraught with a wide divergence of recommended treatment. Odontoid fractures of the elderly are the most common cervical spine injuries in that age group and remain a prominent source of disagreement. We have dedicated a specific review to this subject. The other topic of controversy pertains to the management of AOSpine type A burst (A3 or A4) fractures without associated neurologic or posterior tension band injuries (type B). This is a common injury variant, especially at the thoracolumbar junction, constituting about 45% of all thoracolumbar fractures with proposed treatments ranging from “benign neglect” (mobilization without brace) to highly invasive anterior and posterior surgery. Surgical management offers the possibility of immediate stability and earlier pain control, which may promote early mobilization, avoidance of burdensome orthotic treatment, and prevention of deformity. Nonoperative care offers the avoidance of surgical intervention with its associated morbidity and higher costs. The ongoing controversy is fueled by several studies on one side, which suggest a potential benefit of surgical care relative to patient satisfaction, and overall socio-economic burden, whereas other studies demonstrate improved outcomes and lower morbidity with nonsurgical treatment.13–16
In the last 2 decades, 2 randomized controlled trials were published with conflicting outcomes. In 2003, Wood et al17 presented the results of a randomized study among North American centers in which 47 patients were followed between 1992 and 1998. Outcomes were compared for operative and nonoperative treatment of thoracolumbar burst fractures in neurologically intact patients, which the authors considered to be “stable.” No significant differences were found between the 2 groups with respect to clinical or radiological outcomes at an average follow-up of 44 months. In a recent publication, they presented the long-term follow-up results from 16 to 22 years for the same cohort.18 Seventy-eight percent (37/47) of the original randomized 47 patients were included. Patients treated nonoperatively seemed to have significantly better outcomes for patient-reported pain and function. In this study performed in 1990s, the patients received various surgical techniques, with high complication rates associated with surgical technique that many modern spine centers would now consider “obsolete.” In this multicenter study, the surgical approach was at the discretion of the treating surgeons and consisted of a remarkably wide array of techniques varying from 2 to 5-level posterior stabilization and fusion with pedicle screw-hook instrumentation to anterior alone constructs with one or 2-level fibular and rib-strut grafts. This may explain the contradicting results reported in a more recently published prospective randomized trial by Siebenga et al.19 Patients with a thoracolumbar burst fracture and no neurological deficit from 2 trauma centers in the Netherlands were included. Sixteen patients treated nonoperatively were compared with 18 surgically treated patients. The surgical approach was the same in all cases and consisted of short-segment posterior stabilization with pedicle screws using fixed-angle dedicated fracture reduction implants. Patients treated surgically had significantly better function, less pain, and higher rates of return to work than nonoperatively treated patients. In contrast to the studies by Wood et al, a large prospective multicenter registry study from German and Austrian Trauma Centers has also reported favorable outcomes and far lower complications for surgically treated patients.20 Results favoring surgery for “stable” thoracolumbar injuries with much lower complication rates than previously reported using more modern surgical techniques were also reported in a prospective study from Asian centers as well.13,21 To complete the confusion on this matter, a prospectively randomized study from Canada questioned the role of bracing in “stable” thoracolumbar burst injuries by finding no differences in outcomes and complications of patients who received nothing but activity restrictions and guidance versus those who received usual and customary orthotics. Nonoperative management in itself has remained a poorly defined entity and constitutes another controversy.
Cervical spine injuries studies have been increasing in the more recent past, however without prospective randomized controlled trials. Persistent therapeutic uncertainties of a number of upper cervical spine fractures are discussed in several reviews within this focus issue. For subaxial cervical spine injuries, there continues to be controversy surrounding the safety of closed reduction in certain injury patterns.22
In summary, at this time, there are no definitive guidelines regarding operative or nonsurgical management of common spine injuries in the cervical and thoracolumbar spine where there is minimal risk of secondary neurologic deterioration or high propensity for progressive deformity. It is not clear yet in which of these patients a surgical intervention might be cost-effective. An international multicenter parallel cohort study has recently been launched by AOSpine concerning the thoracolumbar burst fractures, which will hopefully provide some substance to the current medical decision-making.
Surgical Approaches and Techniques
The aim of surgery for spinal trauma is to reduce the fracture and stabilize the injured segments and decompress neurologic tissues if necessary. These aims can be achieved with various techniques depending on surgeon preferences, training, and available resources. The question remains if one surgical approach is superior to others in the surgical effectivity, morbidity, or cost-effectiveness. Regarding the choice of surgical approaches in treating spine fractures, there remains robust disagreement among surgeons.
For the management of subaxial cervical spine injuries, both anterior and posterior approaches showed equivocally satisfactory results without meaningful differences relative to the approach used.23 Relative to thoracolumbar fractures, there is a wide spread of recommended surgical approaches. In their 2004 retrospective review, Verlaan et al24 could not find significant outcomes differences between various surgical approaches. In general, there is consensus that pedicle screw instrumentation offers superior stable fixation. However, there is no consensus if additional anterior surgery is necessary to provide for adequate neural element decompression and maintenance of long-term alignment and bone healing. Considering the morbidity of conventional anterior approaches to the thoracic and lumbar spine, this remains an unresolved issue. At this moment, there is insufficient evidence due to the difficulty of obtaining high-level evidence from prospective studies of spine trauma. The best available data are from a prospective multicenter registry of the German Association of Trauma Surgery. As there are different practices prevalent in the various contributing centers, it is possible to get some comparative data from within the surgically treated cohort of 733 patients. The authors reported no difference in neurologic recovery between posterior only and combined anterior/posterior cases. The correction of sagittal deformity was better maintained in the combined group, but the functional results including pain and return-to-work were superior for patients treated posteriorly only.20 Methodological shortcomings such as limited case matching and different injury severity may have impacted the findings. In general, the controversy about the need for additional anterior surgery after posterior reduction and fixation with pedicle screws has yet to be resolved.
The advent of less invasive surgical techniques over the last decade has only added to the treatment debate. The inherent objective to decrease surgical-approach-related morbidity by decreasing blood loss, surgical site infection, iatrogenic muscle trauma, pain and functional deterioration has resulted in an evolving array of technologies, such as anterior endoscopic decompression and stabilization, posterior percutaneous pedicle screw fixation, temporary spinal external fixator, and open or percutaneous balloon-assisted end-plate reduction and augmentation (BAER) with or without pedicle screw systems.25 Theoretically, these techniques may reduce perioperative morbidities typically for vulnerable patient populations such as the multiply injured and elderly with fractures of an ankylosing spine, thus changing the balance between the theoretical benefits of spinal stabilization and second hit of a major surgery.26 Available evidence however is limited and insufficient to allow for strong treatment recommendations.27 These novel approaches will also affect discussions about nonsurgical versus surgical treatment of many types of spine injuries as the less invasive nature of the interventions may affect the traditional thresholds for surgical indications.
Methods of Nonoperative Management
Many spinal injury types can be managed without surgical intervention. However, it is not always clear what constitutes a “non-surgical treatment.” Immobilization of the spinal column with various external means like collars, braces, casts, and orthoses has a long history and is part of the conventional armamentarium of the spine surgeon. However, it is not clear whether it makes any sense at all to try to “immobilize” spinal column in cases where surgical stabilization is not deemed necessary.28,29 For upper cervical and subaxial cervical spine, halo vest treatment has been shown to provide sufficient stabilization and may be an alternative to surgical stabilization.30 However, this treatment is associated with high complication rates and should only be considered in high volume centers with good infrastructure and experienced personnel. Considering the discomfort, costs and the burden of all these external immobilization devices, it is necessary to be critical of their use especially when we are better able to discriminate between “stable” and “unstable” injury types and surgical fixation is a feasible alternative for all unstable fractures. For cervical spine, there is no evidence for the use of various collars in “stable” type injuries, although this is common practice. For the thoracolumbar spine, several groups have examined the necessity of a brace after type A burst fractures. Two prospective studies in patients with type A burst fractures did not find any differences in vertebral height loss, kyphotic progression, clinical outcomes, or adverse events between those treated with or without an orthosis.31,32 In summary, the common practice of using some kind of external support in the form of collars, braces, casts, or various orthoses is not supported by reliable evidence.
As this short review shows, despite the advances of the last decades, we have still substantial disagreements about some important issues. Of course, some of these discussions may remind the more senior trauma surgeons the controversies about the treatment of long bone fractures before the invention of safe and effective intramedullary nailing techniques.33 Only with combined and coordinated efforts of trauma surgeons and spine surgeons from all around the world, we will be able to reduce the areas of disagreement and prevent unnecessary morbidity, discomfort, and direct and indirect costs to the society.
Care of Elderly Patients With Concurrent Complex Disorders
The rapid demographic changes around the world have presented new challenges in the management of elderly patients affected by injuries of their spines. As we in general are leading longer and healthier lives,2 the spinal column of elderly patients commonly undergoes a number of changes, which raise its vulnerability to spine injuries.
Besides the odontoid fractures discussed before, the geriatric populations in high-income countries show an increasing incidence of traumatic injuries in osteoporotic and/or stiff spinal columns. The presence of reduced bone stock, concurrent arthritic disorders, dementia and loss of other neurocognitive functions, social deprivation, and serious comorbidities with concordant polypharmacy affect management choices and outcomes profoundly in these patients. For odontoid fractures in elderly, 1-year survival rates akin to geriatric hip fractures regardless of treatment paint a grim picture of the depleted general well being of many of the affected patients. With treatment recommendations ranging from benign neglect to early surgical stabilization, there is little consensus on treatment preferences for this important segment of society.
Similarly, an increasing number of studies of fractures associated with ankylosing disorders of the spine suggest an increasing prevalence of this injury entity. There remains some clinical uncertainty as to the differential diagnosis of ankylosing spondylitis, disseminated idiopathic skeletal hyperostosis (DISH), and end-stage spondylosis. Questions persist on a preferred diagnostic algorithm to decrease the incidence of missed injuries. Further, the indications, timing, and the type of surgical intervention in this patient population with considerable medical comorbidities and risk enhancing medications remain in dispute. The impact on patients with missed or nonsurgically treated ankylosing spine injuries can be profound with death and paralysis being especially feared complications in these patients, whereas surgical treatment in itself can be associated with significant morbidity and even mortality.
For many elderly patients with cervical spinal stenosis, a relatively simple blunt impact such as a fall can lead to serious neurologic injury in form of a central cord injury. These injuries commonly do not feature an unstable fracture or cord impact from an acute disc herniation. Although this injury entity is increasingly commonly recognized, there persists therapeutic uncertainty as to the role of surgical intervention in form of a more limited anterior decompression or a more comprehensive but also invasive posterior surgical decompression and fusion. A further question as to timing of surgery also remains unresolved as proponents of a delayed surgery quote lower complications such as blood loss, whereas earlier surgical intervention may have a more favorable neurologic recovery.
Finally, the treatment of osteopenic thoracolumbar fractures remains a source of great debate. With the conclusion of 2 multicenter international prospective randomized controlled trials that showed no discernible differences of vertebroplasty to a sham injection treatment, the subject of vertebral augmentation of vertebral compression fractures seemed to be all but closed. Several more recent trials and registry data using kyphoplasty and vertebroplasty, however, suggest a clear and incremental treatment benefit to some patients with insufficiency injuries. This topic in spine trauma remains a very contentious one with significant socioeconomic impact as nonsurgical and interventional management versions incur significant costs and have strong vocal proponents for their care concepts, with an effective prevention program not in sight. These injury entities affecting a vulnerable and steadily growing segment of our society deserve a closer look at current practices and research insights to aid clinicians in their present day decision-making while offering a platform for future research.
With this focus issue, our collective of international surgeons experienced in spine trauma care sought to highlight many of the currently ongoing debates surrounding spine trauma care and provide a “best evidence for best current practices” framework for clinicians and researchers alike in this fast moving field. As new device technologies and increasingly larger databases become globally available, efforts at abstracting and analyzing larger bodies of current research becomes an increasing opportunity, but also challenge as the frequently contradictory findings have to be put into some clinically meaningful context. This group of surgeons has used the spirit of discovery and international partnership provided by AOSpine International to help spine clinicians with a meaningful survey of the state of the controversies on the important topics in spine trauma.
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