SPINE Volume 31, Number 4, pp 451–458 ©2006, Lippincott Williams & Wilkins, Inc. Neurologic Deterioration Secondary to Unrecognized Spinal Instability Following Trauma–A Multicenter Study Allan D. Levi, MD, PhD,* R. John Hurlbert, MD, PhD,† Paul Anderson, MD,‡ Michael Fehlings, MD, PhD,§ Raj Rampersaud, MD,§ Eric M. Massicotte, MD,§ John C. France, MD,࿣ Jean Charles Le Huec, MD, PhD,¶ Rune Hedlund, MD,** and Paul Arnold, MD†† Study Design. A retrospective study was undertaken their neurologic injury. The most common reason for the that evaluated the medical records and imaging studies of missed injury was insufficient imaging studies (58.3%), a subset of patients with spinal injury from large level I while only 33.3% were a result of misread radiographs or trauma centers. 8.3% poor quality radiographs. The incidence of missed Objective. To characterize patients with spinal injuries injuries resulting in neurologic injury in patients with who had neurologic deterioration due to unrecognized spine fractures or strains was 0.21%, and the incidence as instability. a percentage of all trauma patients evaluated was 0.025%. Summary of Background Data. Controversy exists re- Conclusions. This multicenter study establishes that garding the most appropriate imaging studies required to missed spinal injuries resulting in a neurologic deficit “clear” the spine in patients suspected of having a spinal continue to occur in major trauma centers despite the column injury. Although most bony and/or ligamentous presence of experienced personnel and sophisticated im- spine injuries are detected early, an occasional patient aging techniques. Older age, high impact accidents, and has an occult injury, which is not detected, and a poten- patients with insufficient imaging are at highest risk. tially straightforward problem becomes a neurologic ca- Key words: spinal instability, trauma, spinal clearance, tastrophe. spinal cord injury, radiculopathy. Spine 2006;31:451–458 Methods. The study was designed as a retrospective review of patients who had neurologic deterioration as a direct result of an unrecognized fracture, subluxation, or soft tissue injury of the cervical, thoracic, or lumbar spine from 8 One of the major goals of caring for the trauma patient is level I trauma centers. Demographics, injury information, the early detection and treatment of acute spinal injuries, and neurologic outcome were collected. The etiology and thereby preventing delayed neurologic deterioration incidence of the missed injury were determined. from a missed spinal injury. Although extensive re- Results. A total of 24 patients were identified who were treated or referred to 1 of the participating trauma sources are used to screen patients, the success of trauma centers and had an adverse neurologic outcome as a result teams at attaining this goal is unclear. Several studies of the missed injury. The average age of the patientswas 50 have reviewed the issue of missed injuries in the trauma years (range 18–92), and average delay in diagnosis was population, and the reported incidence of significant 19.8 days. Radiculopathy developed in 5 patients, 16 had spinal cord injuries, and 3 patients died as a result of missed spinal injuries is low, with an exact figure depen- dent on the study population.1–5 However, most of these studies are authored by general trauma surgeons and/or radiologists, with many of the recent reports lacking suf- ficient follow-up. From the *Department of Neurosurgery and the Miami Project to Cure Paralysis, University of Miami, Miami, FL; †Division of Neurosurgery, Spine surgeons in academic centers who specialize in Department of Clinical Neurosciences, University of Calgary, Calgary, trauma have a unique perspective on the issue of clearing Canada; ‡Department of Orthopedic and Neurological Surgery & Re- habilitation, University of Wisconsin–Madison, Madison, WI; §Divi- the spine because they are often the last treating physi- sions of Orthopaedic and Neurosurgery, Toronto Western Hospital, cian in cases in which instability or neurologic deficits Krembil Neuroscience Center, University of Toronto, Toronto, Ontario, from spinal injuries go undetected. There are certain spi- Canada; ࿣Department of Orthopedics, Robert C. Byrd Health Sciences Center, West Virginia University, WV; ¶Department of Ortho- nal fractures that if left undetected, will have only rela- Trauma, Hopital Tripode Pellegrin; **Department of Orthopedic Sur- tively minor consequences to the patient. Although this gery, Karolinska Institute, Huddinge University Hospital; and ††De- may be recorded as a missed injury in some studies, par- partment of Neurosurgery, University of Kansas, Kansas City, KS. Acknowledgment date: December 7, 2004. First revision date: January ticularly studies that use spinal computerized tomogra- 11, 2005. Second revision date: February 22, 2005. Acceptance date: phy (CT) as an end point, the significance of such minor February 23, 2005. fractures is probably limited.6–9 Of major interest is the The manuscript submitted does not contain information about medical device(s)/drug(s). detection and treatment of an injury that if missed, may No funds were received in support of this work. No benefits in any result in neurologic compromise. Because caring for a form have been or will be received from a commercial party related directly or indirectly to the subject of this manuscript. patient who has an adverse event from a missed spinal Address correspondence and reprint requests to Allan D. Levi, MD, injury is unlikely to be forgotten by the attending spine PhD, The Miami Project to Cure Paralysis, University of Miami School surgeon, a retrospective review, even many years after of Medicine, Department of Neurological Surgery, 2nd Floor, D4-6, 1095 NW 14th Terrace, Miami, FL 33136; E-mail: alevi@med. the event, will still likely accurately reflect the trauma miami.edu center’s experience. 451 452 Spine • Volume 31 • Number 4 • 2006 An evaluation of a specific patient population with gathered from 8 centers, including 4 from the United missed spinal injuries that subsequently has neurologic States, 2 from Canada, and 2 from Europe. The retro- deterioration may enable identification of risk factors spective review extended over a period of 2–8 years, associated with such injuries and assist in the improve- depending on the center submitting data. The number of ment of existing spinal protocols. Because these cases are submitted cases ranged from as many as 7 patients to as relatively uncommon events, the number of patients re- few as 1. The incidence of missed fractures resulting in a quired for the study is large. The purpose of this multi- neurologic deficit was calculated using 2 different de- center review was to determine the incidence and clinical nominators. First, the incidence of missed spinal injures factors associated with missing a spinal injury that leads presenting with a neurologic deficit relative to the total to neurologic deterioration. number of diagnosed spine injuries at all participating Materials and Methods centers was 0.21%, or approximately 1 in 500 cases. Second, using the total trauma population (44,520) seen The study was designed as a retrospective review of patients at all institutions as the denominator, the incidence was who presented to the emergency department or trauma service 0.025%, or approximately 1 in 4000 cases. and who had neurologic deterioration as a direct result of an Mean patient age was 50 years (range 18–92). The unrecognized fracture, subluxation, or soft tissue injury of the time to delayed diagnosis ranged from as short as 0 days cervical, thoracic, or lumbar spine from 8 level I trauma cen- to as long as 2 years after injury. There were 2 cases that ters. Spinal surgeons, members of the Spine Trauma Study Group, were surveyed as to whether they had experience in presented 1 and 2 years after injury, and were clearly treating patient(s) who had received “spinal clearance” after a outliers when compared to the other 22 patients. When trauma evaluation and subsequently had significant neurologic these 2 cases were excluded, the average time to delay in deterioration from an unrecognized spinal injury. The Spine diagnosis was 19.8 days. Trauma Study Group is an international group of approxi- The most common etiology of spinal trauma in our mately 50 neurosurgical and orthopedic spine surgeons from cohort was a motor vehicle accident (MVA) occurring in 13 different countries who are dedicated to advancing spine 17 patients, with the remainder stemming from falls (6) trauma care through multicenter analysis and research related and 1 industrial-related accident (Figure 1). Many of the to spine trauma and spinal cord injury. MVAs were high velocity injuries. The majority of spinal Surgeons who had met the aforementioned criteria obtained injuries were cervical cases (21/24), including injuries to institutional review board approval to evaluate further the the occipito-cervical junction (Table 1). The thoracic in- medical records and determine the nature and outcome of the unrecognized instability. To estimate the incidence of missed juries were mainly at the thoracolumbar junction. Mul- spinal injuries, each center was requested to provide data on tiple, nonspinal injuries were present in 8 of 24 patients. patients who were evaluated for trauma over that same period. Many of these concomitant injuries were serious associ- Specific data requested included the number of spine fractures, ated long bone fractures or intra-abdominal