Please rate topic.
Average 2.5 of 17 Ratings
A 40-year-old male patient fell asleep at the wheel and was involved in a motor vehicle accident. At the emergency room, he presented with an ASIA C spinal cord injury. An AP radiograph is shown in Figure A. An axial CT scan at the C5 level is shown in Figure B. Management of this injury should include:
Anterior cervical discectomy and fusion of C5-6
Corpectomy of C5 and instrumented fusion C5-6
Corpectomy of C5 and instrumented fusion C4-5
Posterior instrumented fusion of C4-6
Posterior instrumented fusion of C5-6
Select Answer to see Preferred Response
This patient has fracture separation of the lateral mass. This is best treated with posterior two-level fusion involving both the level above and the level below.
Lateral mass-facet fractures are a result of hyperextension, lateral compression and rotation. Fracture separations of the lateral mass are not well seen on plain radiographs. On axial cut CT scans typically one fracture line is seen through the lamina, and the second through the pedicle. This compromises the stability of the inferior facet (of the vertebra above) and the superior facet (of the vertebra below), leaving the entire lateral mass free from the adjacent vertebral segment, yielding 2 levels of instability. Surgical fixation is indicated in the presence of neurologic injury or segmental instability and should involve instrumented fusion across both levels.
Lee et al. felt that it was unclear whether the management of these injuries should involve anterior, posterior or combined surgical approaches. In their series of 39 patients with 29 lateral mass fractures and 14 facet fractures, they found that nonsurgical treatment was usually unsuccessful, and single-level anterior fusion was adequate. However, for separation type fractures, they report two-level fusion is necessary.
Levine et al. examined 24 patients with this injury. They found that deformity (mean translation 5 mm and angulation 7 deg) occurred more commonly at the level below (80%) than the level above (20%). They opined that because fracture separations were a posterior injury, the preferred surgical approach would be posterior and advocated posterior lateral mass instrumentation.
Kotani et al. classified lateral mass fractures into 4 subtypes. Separation type fractures have 2 fracture lines involving the lamina and pedicle, leading to separation of the articular mass from the vertebral body. Comminution type fractures have multiple fracture lines, including lateral wedging and coronal plane deformity. Split type fractures have a vertical fracture line in the coronal plane, with separation of the lateral mass in the AP plane and upward migration of the superior articular process of the vertebra below. Traumatic spondylolysis fractures have bilateral horizontal fracture lines through the pars interarticularis.
Figure A shows lateralization of the left C5 lateral mass. Figure B shows floating left lateral mass (fracture lines through lamina and pedicle). Illustration A shows the Kotani classification of lateral mass fractures (A, separation; B, comminution; C, split; D, traumatic spondylolysis).
Answer 1: Anterior stabilization is an option, but must involve both the levels above and below (C4-6) for this separation type fracture.
Answers 2,3: The vertebral body is not involved in this injury and corpectomy is unnecessary.
Answer 5: Posterior fusion of C5-6 alone is insufficient as this injury pattern results in 2 level instability (C4-5 and C5-6).
Lee SH, Sung JK
J Trauma. 2009 Mar;66(3):758-67. PMID: 19276750 (Link to Abstract)
Lee, JTACS 2009
Levine AM, Mazel C, Roy-Camille R.
Spine (Phila Pa 1976). 1992 Oct;17(10 Suppl):S447-54. PMID: 1440042 (Link to Abstract)
Levine, SPINE 1992
Kotani Y, Abumi K, Ito M, Minami A
Eur Spine J. 2005 Feb;14(1):69-77. PMID: 15723250 (Link to Abstract)
Kotani, ESPNJ 2005
Please rate question.
Average 3.0 of 7 Ratings