Magnetic resonance imaging of sports injuries to the cervical spine

Fortunately, serious injuries to the cervical spine in athletes are rare. Most injuries are self-limited and related to sprains and strains. Although radiographs may be used to screen for fractures, potentially serious soft-tissue injuries require additional diagnostic techniques. In these cases, advanced imaging with computed tomography and/or magnetic resonance imaging (MRI) is important to assess the injury and determine treatment and prognosis. MRI is well suited to imaging the cervical spine and to evaluate injuries. This article reviews cervical spine imaging in the athlete, with an emphasis on MRI. It groups pathology into stability, impingement, and impairment and discusses causes and radiological assessment of each group.     

Multidetector computed tomography of cervical spine fractures in ankylosing spondylitis

PURPOSE: To analyze multidetector computed tomography (MDCT) cervical spine findings in trauma patients with advanced ankylosing spondylitis (AS). MATERIAL AND METHODS: Using PACS, 2282 cervical spine MDCT examinations requested by emergency room physicians were found during a period of 3 years. Of these patients, 18 (16 M, aged 41-87, mean 57 years) had advanced AS. Primary imaging included radiography in 12 and MRI in 11 patients. RESULTS: MDCT detected one facet joint subluxation and 31 fractures in 17 patients: 14 transverse fractures, 8 spinous process fractures, 2 Jefferson's fractures, 1 type I and 2 type II odontoid process fractures, and 1 each: atlanto-occipital joint fracture and C2 laminar fracture plus isolated transverse process and facet joint fractures. Radiographs detected 48% and MRI 60% of the fractures. MRI detected all transverse and odontoid fractures, demonstrating spinal cord abnormalities in 72%. CONCLUSION: MDCT is superior to plain radiographs or MRI, showing significantly more injuries and yielding more information on fracture morphology. MRI is valuable, however, in evaluating the spinal cord and soft-tissue injuries. Fractures in advanced AS often show an abnormal orientation and are frequently associated with spinal cord injuries. In these patients, for any suspected cervical spine injuries, MDCT is therefore the imaging modality of choice.     

Thoracic and lumbar spine trauma

The frequency and distribution of fractures of the thoracic and lumbar spine are reviewed. Classifications of thoracolumbar spine injuries are considered. Compression or wedge fractures, burst fractures, lap seat-belt-type injuries, and fracture-dislocations are considered with discussion of findings on conventional radiography and computed tomography. The concepts of stability and instability are briefly discussed and the relative advantages of computed tomographic imaging are reviewed.     

Chronic repetitive unrecognized flexion injury of the cervical spine (high jumper's neck)

Unrecognized flexion injuries of the cervical spine may lead to late instability and neurologic damage. These hidden flexion injuries may be from acute or chronic traumatic episodes. Cervical spine instability was seen in an amateur high jumper as a result of chronic repetitive flexion loading of her cervical spine due to incorrect landing technique. The instability from these types of flexion injuries is generally unrecognized on a routine lateral radiograph. The presence of slight anterior subluxation, simple compression fractures, or subtle kyphotic angulation at one cervical level should alert the physician to this diagnosis. Flexion extension views are useful to demonstrate this instability. Occupations and sports which involve repetitive flexion stress to the cervical spine are at risk for this type of late instability. Therefore, in high jumping careful attention to safe techniques of landing is of utmost importance.     

Spine fractures in winter sports

In a 7-year review of 1,447 spine fractures, 202 (14%) were due to sporting or recreational causes, of which 84 (42%) were associated with paralysis. This high incidence catastrophic injury is second only to motor vehicle accidents. Snowmobiling (10%), skiing (5%), tobogganing (5%) and ice hockey (3%) accounted for approximately one-quarter of these injuries. Snowmobile injuries rose steadily over this period, and the main contributing factors were alcohol, poor lighting, young age and inappropriate terrain. The skiing injuries occurred to novices and top class skiers alike, with one-third of those sustaining a fracture having associated paralysis. In view of the terrain and the speeds involved, the figure is unlikely to change. An alarming trend was the subtle increase in cervical fracture due to ice hockey, most of which were compression injuries with the neck in the neutral or slightly flexible position, and secondary to a collision with the boards. Being decked from behind contributed to the impact. The introduction of measures to reduce these injuries is mandatory, since cervical fractures secondary to ice hockey were associated with permanent paralysis in 67% of the cases. There are several points of initial management which require emphasis.     

MRI of cervical spine injuries complicating ankylosing spondylitis

OBJECTIVE: The objective was to study characteristic MRI findings in cervical spine fractures complicating ankylosing spondylitis (AS). Technical issues related to MRI are also addressed. MATERIALS AND METHODS: A review of 6,774 consecutive cervical spine multidetector CT (MDCT) scans obtained during 6.2 years revealed 33 ankylosed spines studied for suspected acute cervical spine injury complicating AS. Of these, 20 patients also underwent MRI. RESULTS: On MRI, of these 20 patients, 19 had a total of 29 cervical and upper thoracic spine fractures. Of 20 transverse fractures traversing both anterior and posterior columns, 7 were transdiskal and exhibited less bone marrow edema than did those traversing vertebral bodies. One Jefferson's, 1 atlas posterior arch (Jefferson's on MDCT), 2 odontoid process, and 5 non-contiguous spinous process fractures were detectable. MRI showed 2 fractures that were undetected by MDCT, and conversely, MDCT detected 6 fractures not seen on MRI; 16 patients had spinal cord findings ranging from impingement and contusion to complete transection. CONCLUSION: Magnetic resonance imaging can visualize unstable fractures of the cervical and upper thoracic spine. Paravertebral hemorrhages and any ligamentous injuries should alert radiologists to seek transverse fractures. Multiple fractures are common and often complicated by spinal cord injuries. Diagnostic images can be obtained with a flexible multipurpose coil if the use of standard spine array coil is impossible due to a rigid collar or excessive kyphosis.     

Acute spine injuries in skiers and snowboarders

Skiing and snowboarding are popular winter sports associated with significant traumatic spinal injuries. Despite a decline in most injuries related to these sports over the years, acute injury rates of the spine have remained stable and even increased. Vertebral fractures and spinal cord injuries are the most common serious acute injuries of the spine in skiers and snowboarders. Due to the unique characteristics of each sport, different injury mechanisms are responsible for the majority of injuries. This article reviews injury patterns, injury types, mechanisms of injury, and strategies for prevention of spine injuries in skiers and snowboarders.     

Wrist Trauma: More Than Bones

Acute and subacute wrist trauma predominantly consist of fractures of the distal radius in elderly patients and most frequently carpal fractures (scaphoid, followed by triquetrum and hamatum) and avulsion fractures of the ulnar styloid in younger patients, especially in sports-related injuries but also in work activities. The initial radiographs may miss the fractures and result when untreated in complications as nonunion, osteonecrosis, and degenerative osteoarthritis.Fractures of the distal radius and of the scaphoid may be associated with ligament injuries, most frequently the scapholunate complex, which are often overlooked at the emergency department. Patients without osseous injuries may present intrinsic and extrinsic ligament tears that may lead to carpal instability when they are clinically and/or radiologically missed.Therefore, in acute and subacute setting, computed tomography may be helpful for the detection of subtle fractures, and magnetic resonance imaging, for the early diagnosis of occult fractures and ligament injuries.     

Hyperextension fracture-dislocation of the thoracic spine

Extension injuries of the thoracolumbar spine are rare and often are not included in classifications of thoracolumbar trauma. Hyperextension fracture-dislocation of the thoracolumbar spine is characterized radiographically by widening of the intervertebral disc space anteriorly. Additional features may include retrolisthesis, impaction fractures of the middle and posterior columns, and anterior inferior endplate corner fractures. Magnetic resonance imaging typically reveals rupture of the anterior longitudinal ligament and hemorrhage into the disc space, and it may demonstrate associated soft tissue or spinal cord injury. We present a case of hyperextension fracture-dislocation of the thoracic spine in a middle-aged female involved in a motor vehicle collision and discuss the salient features of this injury.     

The value of routine cervical spine,chest, and pelvis radiographs in children after trauma

The appropriate use of imaging to screen infants and children for injuries after trauma remains controversial, and routine radiographs of the cervical spine, chest, and pelvis are still obtained at some centers. The purpose of this study was to document the abnormalities encountered on such films obtained in 292 pediatric trauma patients to evaluate the worth of obtaining such studies, particularly in children who are asymptomatic and have no clinical findings referable to these areas.The medical records, radiographs, and other imaging studies of 292 children evaluated in the emergency department after trauma were retrospectively reviewed. Ages ranged from 5 months to 17 years (mean =10 years). The numbers and types of abnormal imaging findings were documented for each patient and were correlated with the type of injury, patient complaints, physical examination findings, level of consciousness, and laboratory abnormalities. Final diagnosis and short-term outcome were also documented.The most common causes of injury were motor vehicle accidents (55.1%), automobile-pedestrian accidents (14.7%), and falls (13.4%). Acute cervical spine injuries were found in 2 patients (0.7%), radiographic abnormalities of the chest were found in 11 patients (3.8%), and pelvic fractures were detected in 6 patients (2.0%). All except 1 of the 19 confirmed injuries were associated with local symptoms and/or signs or were found in patients with altered mental status. A stable cervical fracture was found in one infant who was too young to complain of neck pain or tenderness. Twenty-two patients (7.5%) were asymptomatic with no physical findings, and in none of these children were any imaging abnormalities detected.We conclude that routine posttrauma radiographs of the cervical spine, chest, and pelvis are of limited utility and are not warranted in children and adolescents who are alert and demonstrate no associated symptoms or physical findings. Radiography, particularly of the cervical spine, may be worthwhile in infants and young children, but we advocate selective imaging in such patients.     

Predicting radiology resident errors in diagnosis of cervical spine fractures

RATIONALE AND OBJECTIVES: Our objective was to identify factors associated with resident errors of cervical spine fractures to enable targeted education. MATERIALS AND METHODS: We performed a retrospective cohort study of consecutive cases of after-hours resident interpreted cervical spine fractures over 27 months at a single level 1 academic trauma center. The outcome measure was appropriate identification of all fractures by the resident. Potential predictors of resident error or discrepancy were identified from chart review and included: age, gender; fracture location/pattern (upper/lower cervical spine, occipital condyle, C1 ring, dens, C2 pars, vertebral body, posterior column, lateral mass, transverse process); consecutive and nonconsecutive additional fractures; radiologist distracting factors (number of noncervical spine injuries); number of noncervical spine studies performed. Risk ratios with confidence intervals were calculated for categorical variables using epidemiological 2 x 2 tables, and for continuous variables using difference of means. RESULTS: There were 59 errors among 492 cervical spine fractures in a total of 327 patients. Fifty-seven of the errors were on computed tomography and 2 errors were on radiographs. Upper cervical fractures were significantly more likely to have been errors than lower cervical fractures: risk ratio (RR) of 2.2 (confidence intervals (CI) 1.3, 3.5; P = .001). Occipital condyle fractures were more likely to have been discrepant: RR = 2.2 (CI 1.3, 3.9; P = .006). Dens fractures were also significantly more likely to have been discrepant: RR = 2.0 (CI 1.0, 3.8; P = .05). Other potential predictors were not associated with significantly increased risk. CONCLUSION: Upper cervical spine fractures, in particular occipital condyle and dens fractures were significantly associated with an increased relative risk of resident missing or misinterpreting the fracture. These findings suggest that resident education should focus in particular on upper cervical spine injuries, occipital condyle, and dens fractures. The methods used in this study could also be applied to other imaging modalities and anatomic regions in the future to target resident education to more challenging areas.     

Cervical spine injury in the elderly: imaging features

An increase in the elderly population has resulted in an increased incidence of cervical spine injury in this group. No specific type of cervical spine trauma is seen in the elderly, although dens fractures are reported to be common. Hyperextension injuries due to falling and the resultant central cord syndrome in the mid and lower cervical segments due to decreased elasticity as a result of spondylosis may be also characteristic. The imaging features of cervical spine injury are often modified by associated spondylosis deformans, DISH and other systemic disorders. The value of MR imaging in such cases is emphasized. Received: 14 April 2000 Revision requested: 30 June 2000 Revision received: 18 August 2000 Accepted: 4 October 2000     

Lap-belt injuries of the lumbar spine in children: a pitfall in CT diagnosis

A retrospective review of 365 consecutive CT studies in children assessed for intraabdominal trauma yielded five children in whom lap-belt-associated injuries of the lumbar spine were missed on CT. Facet subluxation and anterior dislocation of the third lumbar vertebra were present in four patients and multiple compression fractures were present in one. Clinical presentations included acute abdominal symptoms; two had acute back pain, and three experienced delayed onset of back pain. Although the injuries to the spine were visible retrospectively on anteroposterior radiographs, the findings were subtle and their extent was best appreciated on lateral lumbar spine views. Five of 365 patients with blunt abdominal trauma were identified as having sustained midlumbar spinal injury that was clearly visible only on a lateral radiograph of the spine.     

MRI and discography in traumatic intervertebral disc lesions

In this study we evaluated magnetic resonance imaging (MRI) in trauma patients for assessing traumatised adjacent discs of fractured vertebrae before dorsoventral stabilisation. In a prospective study, MRI of 54 discs was performed with a 1.5-T MRI unit. The preoperative MRI with sagittal T1-W-SE and T2-W-TSE was compared to intraoperative discography, which was carried out on both intervertebral discs adjacent to the fractured vertebrae. Signal alterations, morphological changes in the adjacent discs, fractured vertebrae and associated ligament injuries were evaluated. In 47/54 (87%) of the intervertebral discs, the results of both imaging findings were concordant. The discs adjoining vertebral fractures were normal in 18 cases. Regarding the positive concordant imaging findings, MRI and discography revealed traumatised adjacent cranial and caudal discs in 22 discs. In 7 cases, only the cranial adjacent disc was affected. Moreover, 17 cases of intradiscal bleeding, 13 intraosseous herniations into the fractured vertebrae and 20 anuluar tears were visualised in MRI. Associated ligament injuries were detected in 18 cases. Findings were discordant in eight discs. In six discs, MRI was abnormal, demonstrating signal alterations suggestive of positive imaging findings, whereas discography demonstrated no disc injury. MRI failed to detect disc injury in two discs, whereas discography was positive, showing an irregular intradiscal contrast media distribution. MRI, as a non-invasive method for assessing fractures of the thoraco-lumbar spine, may detect traumatised adjacent intervertebral discs. MRI is superior to intraoperative discography. The performance of MRI of the thoraco-lumbar spine is recommended before dorsoventral stabilisation in trauma patients, as it can reveal additional preoperative information such as fractures, disc and associated ligament injuries.     

Physical examination and imaging of the lateral collateral ligament and posterolateral corner of the knee

Diagnosis of posterolateral corner injuries can be challenging. Understanding the mechanism of injury in combination with careful history taking and a thorough physical examination are crucial. Clinical findings may be subtle, especially in the acute setting. Specialized tests such as external rotation recurvatum test, posterolateral drawer test, reverse pivot shift test, and dial test are particularly helpful. A characteristic radiographic finding is the arcuate sign, whereas medial Segond fractures can be associated with posterolateral corner injuries. Magnetic resonance imaging is most useful when performed with a high strength magnet utilizing a coronal oblique technique. Prompt and accurate diagnosis of posterolateral corner injuries allows the orthopedist to initiate the appropriate repair and reconstruction procedures to assure optimum treatment results.     

MRI of anterior cruciate ligament injuries and associated findings in the pediatric knee: changes with skeletal maturation

OBJECTIVE: The objective of our study was to evaluate the MRI characteristics of anterior cruciate ligament (ACL) injuries and associated findings relative to skeletal maturity. We also contrast the frequency of findings in this younger population to adult data. MATERIALS AND METHODS: Eighty-two consecutive knees with an MRI report diagnosis of ACL injury (partial tear, sprain, or complete tear) or tibial spine avulsion fracture imaged over 4 years were retrospectively reviewed. Patients were grouped by degree of skeletal maturity as determined from the MR images. The examinations were reviewed for the type of ACL injury, secondary imaging findings, and associated knee injuries. Findings were correlated to skeletal maturity, and frequencies were compared with adult data. RESULTS: ACL injuries were more common in boys in the skeletally immature group, but more common in girls in the skeletally mature group (p = 0.03). Tibial spine avulsion fractures were most common in skeletally immature patients (p < 0.01), whereas complete tears of the ACL were most common in skeletally mature patients. Associated injuries were less common in the skeletally immature group, but this trend did not reach statistical significance. Most secondary signs of ACL injuries occurred at similar rates in all groups with frequencies similar to those reported in adults. CONCLUSION: ACL injuries in skeletally immature patients are seen more often in boys. Tibial avulsion fractures and partial tears are more common in younger, less rigid skeletons that may absorb the forces of trauma. As children mature, complete ACL tears and associated injuries occur in frequencies approaching those patterns seen in adults. Similarly, skeletally mature girls are affected more often than mature boys.     

Radiologic and clinical spectrum of occipital condyle fractures: retrospective review of 107 consecutive fractures in 95 patients

OBJECTIVE: We proposed to characterize the radiologic spectrum of occipital condyle fractures in a large series of patients and to correlate fracture pathology with neurosurgical treatment and patient outcome. MATERIALS AND METHODS: We conducted a retrospective review of the findings on conventional radiography, CT, and MR imaging in 95 patients with 107 occipital condyle fractures. We described fracture patterns according to two previously published classification systems. Clinical findings, neurosurgical management, and patient outcome were obtained from the medical records. RESULTS: Inferomedial avulsions (Anderson and Montesano type III) were the most common type of occipital condyle fracture, constituting 80 (75%) of 107 overall fractures. Unilateral occipital condyle fractures were found in 73 (77%) of 95 patients, and 58 patients were treated nonoperatively; occipitocervical fusion was required in nine patients for complex C1-C2 injuries, and six patients died. Bilateral occipital condyle fractures or occipitoatlantoaxial joint injuries were seen in 22 (23%) of 95 patients. Occipitocervical fusion or halo traction for the craniocervical junction was required in 12 patients, all of whom had CT evidence of bilateral occipitoatlantoaxial joint disruption and six of whom showed normal craniocervical relationships on conventional radiographs. Six patients with nondisplaced fractures were treated nonoperatively, and four patients died. Thirty (32%) of 95 patients showed continued disability, whereas 55 (57.5%) of 95 patients had good outcomes at 1 month. Associated cervical spine injuries were present in 29 (31%) of 95 patients. CONCLUSION: Given their associated traumatic brain and cervical spine injuries, occipital condyle fractures are markers of high-energy traumas. That conventional radiographs alone may miss up to half of the patients with acute craniocervical instability has not been well established. Avulsion fracture type and fracture displacement are associated with both injury mechanism and the need for surgical stabilization. In this series, most unilateral occipital condyle fractures were treated nonoperatively, whereas bilateral occipitoatlantoaxial joint injuries with findings of instability usually required surgical stabilization.     

Subchondral bone infractions in acute ligamentous knee injuries demonstrated on bone scintigraphy and magnetic resonance imaging.

Bone scintigraphy is used to detect radiographically silent fractures. Magnetic resonance imaging (MRI) is currently used to screen knee injuries for cartilage and ligament damage. MRI also delineates bone marrow and fractures. We investigated the bone scintigraphic findings in patients who had subchondral bone injuries demonstrated on MRI. Thirteen patients underwent MRI, three-phase bone scintigraphy with SPECT, and arthroscopic surgery after sustaining acute traumatic hemarthrosis of a knee. They all had clinically unsuspected subchondral bone injuries demonstrated on MRI with normal radiographs and normal overlying articular cartilage at arthroscopy, consistent with occult fractures. All showed focal bone repair on scintigraphy. Two of the 13 patients showed additional bone injuries only on bone scan. Two other patients scintigraphically showed focal bone repair at the medial femoral condyle due to avulsion of the medial collateral ligament. SPECT was easier to interpret than multi-view planar imaging. Bone scintigraphy confirms subchondral fractures demonstrated on MRI but also demonstrates ligament avulsion injuries and additional more subtle bone injuries.     

Magnetic resonance imaging findings of golf-related injuries

Injuries related to participation in golf are becoming more common given the increasing popularity of the sport itself. Golf is considered to be an activity associated with a moderate risk for sports injuries. Golf injuries are usually attributable to overuse or traumatic mechanisms and primarily occur at the elbow, wrist, shoulder, and lumbar spine. None of these injuries are unique to golf, but each of these injuries represent the most common injuries associated with golfing. This article reviews a wide range of injuries that are encountered in golfers and describes the magnetic resonance imaging findings of each of these injuries.     

Imaging in spinal trauma

Because it may cause paralysis, injury to the spine is one of the most feared traumas, and spinal cord injury is a major cause of disability. In the USA approximately 10,000 traumatic cervical spine fractures and 4000 traumatic thoracolumbar fractures are diagnosed each year. Although the number of individuals sustaining paralysis is far less than those with moderate or severe brain injury, the socioeconomic costs are significant. Since most of the spinal trauma patients survive their injuries, almost one out of 1000 inhabitants in the USA are currently being cared for partial or complete paralysis. Little controversy exists regarding the need for accurate and emergent imaging assessment of the traumatized spine in order to evaluate spinal stability and integrity of neural elements. Because clinicians fear missing occult spine injuries, they obtain radiographs for nearly all patients who present with blunt trauma. We are influenced on one side by fear of litigation and the possible devastating medical, psychologic and financial consequences of cervical spine injury, and on the other side by pressure to reduce health care costs. A set of clinical and/or anamnestic criteria, however, can be very useful in identifying patients who have an extremely low probability of injury and who consequently have no need for imaging studies. Multidetector (or multislice) computed tomography (MDCT) is the preferred primary imaging modality in blunt spinal trauma patients who do need imaging. Not only is CT more accurate in diagnosing spinal injury, it also reduces imaging time and patient manipulation. Evidence-based research has established that MDCT improves patient outcome and saves money in comparison to plain film. This review discusses the use, advantages and disadvantages of the different imaging techniques used in spinal trauma patients and the criteria used in selecting patients who do not need imaging. Finally an overview of different types of spinal injuries is given.