Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms

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Teardrop fracture following head-first impact in an ice hockey player: Case report and analysis of injury mechanisms

A 17-year old male athlete participating in a fall league ice hockey game reported that he and an opponent, who had the puck, skated towards each other at high speed. The athlete tripped over a teammate's stick, fell forward, and the top of his helmet forcefully impacted the opponent’s leg at approximately mid-thigh.

At the time of impact, his neck was straight and his stick was held in front of him with both hands. His stick broke upon contact with the opponent, likely the lower leg, at approximately the same time the head impact occurred. He was unable to get up and reported feeling pins and needles in his hands and upper arms. The patient reported approximately 1 minute of functional quadriplegia. Neck pain after the impact was minimal. He had transient quadriplegia until external stabilization and distraction could be applied with a well-fitting halo-vest. His leg function returned prior to arm function.

What is the most likely diagnosis of this case presentation?

  • Vertebral dislocation
  • Teardrop fracture
  • Vertebral compression fracture

 

Introduction

Teardrop fracture is the most severe1 and unstable injury of the cervical spine resulting in permanent quadriplegia in the vast majority of cases2-4 and even death.5 The injury involves forward displacement of an anterior fracture fragment of the vertebral body (VB); midsagittal fracture of the posterior VB fragment with retropulsion causing cord compression and neurological sequelae; one or more neural arch fractures; widening of the interlaminar spaces, interspinous spaces, and facet joints; and ligamentous disruption at the intervertebral level inferior to the affected vertebra.2,4,6 It occurs most often at C5, followed by C6, and C4, and has been reported at multiple adjacent vertebrae.4-6

Teardrop fracture is caused by high-energy axial compression of the flexed cervical spine due to trauma involving head impact.2,7 Spinal cord injuries in ice hockey are most commonly reported due to head-first impact into either the boards or an opponent.8,9 While the global mechanistic events are well understood, less is known regarding the etiology of the specific teardrop fracture patterns observed clinically. Teardrop fracture etiology is dependent in part upon vertebral anatomy. A VB of the middle or lower cervical spine has distinct features: 1) a superior surface with uncinate processes that project upward from its lateral margins and 2) a saddle-shaped inferior surface,10 convex laterally and concave anteroposteriorly with the anteroinferior corner often skewed forward.11,12 Bilateral Luschka joints, between the uncinate processes and the inferior borders of the adjacent VB, have been shown in mathematical modeling to increase cervical motions, while the uncinate processes reduce motions and coupling.13

The anterior fracture fragment forming the teardrop is hypothesized to have been sheared off of the larger posterior VB fragment.6 This is due to its forced compression between the adjacent bodies in a preflexed posture with the fracture line of the “teardrop” related in part to the sagittal plane concavity of the inferior endplate. Continued compressive load combined with flexion causes retropulsion of the posterior VB fragment resulting in cord compression injury. Several hypotheses exist regarding the etiology of the vertical VB fracture in the sagittal plane caused by the compressive load. Some believe that the superior nucleus is forcibly wedged into the superior endplate causing it to split and spread.14 Another hypothesis is that the fracture may initiate and propagate at the basivertebral veins.12 Vertebral arterial anatomy indicates that the largest vein enters the posterior surface of the VB in the midsagittal plane and penetrates to approximately half its anteroposterior width.15 Lastly, the compression load may decrease the height of the superior disc and increase its hoop tension which transfers lateral forces to the uncinate processes causing their outward expansion.12 The lateral forces which separate the right and left sides of the VB often cause associated fractures of the neural arch.

The purpose of the present study was to report a case of an athlete who suffered neurapraxia, yet made full neurological recovery, after sustaining cervical teardrop fracture due to a head-first impact in ice hockey. The etiology and biomechanical mechanisms of injury based upon the injury causing environment, patient characteristics, review of the patient’s medical records and diagnostic images, and syntheses of prior case series and biomechanical studies were investigated.

Medical History

Prior to the accident, our patient was in overall good health and good physical condition and did not have a history of smoking or usage of alcohol or illicit drugs

Examination and Laboratory Investigations

Upon arrival at the emergency room of an off-site facility, the patient experienced neck pain and transient quadriparesis. Admission computed tomography (CT), MRI scans and neurological examination performed at the off-site facility revealed a teardrop fracture of the C5 vertebra. In addition to CT scan, MRI

Treatment

The upper cervical column, consisting of C5 and superior vertebrae, was displaced posteriorly relative to the lower column. The posteroinferior corner of the C5 VB was displaced 4.0 mm into the spinal canal. The sagittal plane CT sequence demonstrated a quadrilateral-shaped fracture fragment of the anterior VB with fracture comminution of its superior and anterosuperior regions. This anterior fracture fragment was displaced forward and rotated in extension. Its anteroposterior width was 6.3 and 4.7 mm at its inferior and superior surfaces, respectively, corresponding to 42% and 34% of the total VB width. A horizontal gap of 4.4 mm was measured inferiorly between the anterior and posterior VB fracture fragments in the midsagittal plane. The frontal plane CT sequence of the posterior VB fragment demonstrated its vertical fracture in the sagittal plane. The heights at the anterior and middle of this fracture fragment were 67% and 77% of the posterior cortex height. At the posterior cortex, vertical fracture was offset to the right of the midsagittal plane by 0.8 mm as it extended from the superior surface to the middle of the VB and shifted to the midsagittal plane at the inferior surface of the VB. This shift was more pronounced at the mid region.

The transverse plane CT sequence demonstrated the aforementioned fractures in addition to neural arch fractures. Incomplete fractures that initiated superiorly were observed at the anterior aspect of spinous process and left lamina adjacent to the superior facet. The spinous process fracture was associated with an incomplete fracture of the right lamina observed at mid-height of the arch.

MRI demonstrated the retropulsion of the upper cervical column with epidural hematoma in the region of the C5 vertebra. Disc and ligamentous disruptions were observed at C4-5 and C5-6. Neurological examination indicated sensation was grossly present in the C5-S1 nerve distribution with subjective paraesethesias in the C5, C6, and C7 distribution. Halo-vest fixation was applied. Anterior cervical fusion was performed. The halo-vest was removed and a cervical collar and tongs with 10 lbs traction were applied which produced satisfactory spinal alignment. A left anterolateral approach to the cervical spine was used. Interspace distraction using Caspar pins did not reveal significant facet separation at the site of injury.

Discectomies were performed at C4-5 and C5-6 out to the Luschka joints. Central corpectomy was performed at C5 with removal of the posterior cortex and remaining posterior longitudinal ligament. A large fragment of posterior cortex was evident within the canal. A tricortical iliac crest bone graft was inserted and the traction weight removed. The graft was found to be very stable. Anterior plate fixation was applied at C4 through C6. The patient was able to move all extremities immediately following the operation. Nonunion was observed at 5 months at C5-6 which was treated with bilateral posterior fusion.

Discussion

Pleural effusions in Rheumatoid arthritis are most common in patients with a long history of active articular disease and rheumatoid nodules6. Massive pleural effusions as a presenting feature of RA are uncommon and are a diagnostic challenge in the absence of arthritic symptoms. The characteristic 1:320) that exceed levels in the serum (though this was not analyzed in our case) and low C3 and C4 complement levels7. Lymphocyte predominance is the norm but neutrophilia may also be seen. This case demonstrates the challenges faced in the diagnosis of rheumatoid pleuritis in a patient with serum negative rheumatoid factor, absence of arthritic symptoms and a primary presentation of massive recurrent pleural effusion with acute respiratory failure. The distinctive feature of this case report is the significant presentation without associated arthritis. Serum positive rheumatoid factor is seen in 95% of patients with RA associated effusions8. Rheumatoid factor in pleural fluid was not checked. Another unique feature of this case is the pleural fluid eosinophilia which is a rare finding8. The characteristic findings of pleural fluid (low glucose, high LDH), after exclusion of infection and malignancy together with the high titers of Anti-CCP antibody helped in clinching the diagnosis. Furthermore, his response to prednisone and methotrexate with completion resolution of effusion and absence of recurrence further supported the diagnosis.

Small and asymptomatic rheumatoid pleural effusions do not require any treatment. Most cases will resolve spontaneously or with treatment of underlying rheumatoid arthritis9. Treatment of large and symptomatic pleural effusion includes NSAIDS, repeated thoracentesis, oral and intra pleural steroids. These modalities of treatment have shown inconsistent benefits and treatment of underlying rheumatoid arthritis may be most helpful9. Pleurodesis may be considered in refractory effusions9. Decortication may be required in cases of lung entrapment from severe pleural thickening 1,9.

Learning

Case studies which describe mechanisms of teardrop fracture due to sports impacts may help guide and inform future biomechanical investigations for creating realistic injures. These data may ultimately lead to:

  • Increased awareness of the injury among athletes, coaches, trainers, and referees

  • Improved training techniques; rule modifications; and design of safer protective equipment and athletic facilities

  • The data may also provide clinical guidance and information when choosing optimal patient position intraoperatively and during transport, performing reduction and alignment, and choosing the most appropriate internal or external fixation

References

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