The Radiographic Failure of Single Segment Posterior Cervical Instrumentation in Traumatic Cervical Flexion Distraction Injuries

Abstract

Background/Objectives: Unilateral and bilateral cervical facet subluxations, dislocations, and/or fractures may be managed with anterior, posterior, or combined surgical approaches. The primary objective of this study was to identify radiographic features that predispose to poor radiographic outcomes (kyphosis) when these injuries are treated with single segment posterior cervical instrumentation and fusion. Method: A retrospective radiographic review was performed on 65 patients whose unilateral or bilateral facet subluxation/dislocations or fracture dislocation was managed with single segment posterior cervical instrumentation and fusion. The pre-and postoperative plain radiographs, CT, and MRI were assessed to identify the fracture type, degree of kyphosis, translation, and radiographic failure. Results: 2 patients (3.5%) demonstrated gross radiographic failure of the posterior instrumentation. Both had bilateral facet subluxation without fracture and ultimately required anterior revision. Kyphosis at follow-up was significantly correlated with kyphosis on the initial injury films (p = .007) and bilateral facet subluxation (p = .005). There was no correlation between follow-up kyphosis and the degree of preoperative translation, injury level, facet or endplate fracture, age, gender, or surgeon. There was no difference between the use of lateral mass plates or interspinous wires. Conclusion: This study confirmed a high union rate (96.5%) and satisfactory overall alignment with single segment posterior cervical instrumentation and fusion in these injuries. There is a high risk of poor postoperative sagittal alignment in patients with bilateral facet subluxation without fracture and in those with significant preoperative kyphosis. In patients with these high risk factors, a better radiographic result may be obtained with combined anterior and posterior surgery rather than with posterior fixation alone.

The Surgical Approach to Subaxial Cervical Spine Injuries

“…13 There were 3 level II articles 14 -16 and 7 level III articles, 12,[17][18][19][20][21][22] which are presented in Table 2. The study selection process eliminated 526 articles by a review of the abstracts alone.…”

“…2,7,8,13,20,21 Ensuring tight, 100% apposition of the facets, a trapezoidal interbody graft, and contouring of the plate into lordosis will optimize the stability of this anterior approach for what is primarily a posterior ligamentous injury. 47 Specific to bilateral facet subluxations, however, are the findings of a study by Elgafy et al, 17 wherein patients with bilateral facet subluxations (perched facets without fracture) were found to develop higher degrees of kyphosis after posterior instrumented fusion. 16,41 When the disc is essentially intact or merely disrupted without frank herniation, then the surgeon can make a choice either anterior or posterior fixation based on patient and surgeon preference.…”

A prospective randomized controlled trial of anterior compared with posterior stabilization for unilateral facet injuries of the cervical spine

“…Data from a subsequent retrospective analysis of a larger but more heterogeneous cohort of patients with cervical flexion-distraction injuries treated using wire fixation, lateral mass fixation, or both revealed no significant difference in fusion rates between the two treatment groups. 9 In summary, this study was ultimately conducted to determine whether anterior or posterior fixation was superior in the surgical management of isolated unilateral facet injuries, with the primary determinant of superiority being the time required to achieve discharge criteria in the early postoperative period. Although not powered as an equivalence study, we have provided level 1 evidence that both anterior and posterior treatments are reasonable alternatives.…”

Role of Decompressive Surgery in Disorders Associated with Spinal Cord Lesions

“…Of note, some degrees of post-surgical kyphosis are identified in patients treated with posterior fixation, which is thought to result from intervertebral disc injury and progressive collapse. Although the longterm clinical effects of this finding is yet to be evaluated, pre-operative sagittal alignment of the spinal column in patients with facet injuries should be noted prior to undergoing anterior or posterior stabilization (Lifeso 2000;Elgafy 2006).…”