J Korean Orthop Assoc.  2022 Oct;57(5):409-418. 10.4055/jkoa.2022.57.5.409.

Risk Factors for Reduction of Facet Joint Dislocation by Preoperative Traction in Distractive-Flexion Injury of the Lower Cervical Spine

• Kim TH
• Kim MW
• Song WB
• Ko JH
• Song KJ

• KMID: 2534395
• DOI: http://doi.org/10.4055/jkoa.2022.57.5.409

Abstract

Purpose
The treatment strategy of Distractive-Flexion Injury (DFI) depends on the preoperative reduction, and anterior surgery is usually sufficient for closely reduced DFI. In contrast, reduction-failed injuries should be reduced by more complex procedures. This study evaluated the risk factors of closed reduction and identified the factors that can predict reducibility.
Materials and Methods
Fifty patients who underwent surgical treatment due to unstable DFI (Allen stage 2 or higher) from 1994 to 2018 were enrolled in this study. All patients underwent Gardner–Wells tongs traction preoperatively. The patients were subdivided into two groups (group A: reduced, group B: failed reduction). The degree of dislocation and subluxation of the facet joints were analyzed by computed tomography. The major injured facet (MIF) joint was defined as a dislocated joint with more damage, and the opposite facet joint was defined as a minor injured facet joint (mIF) with subluxation. The severity of a MIF injury was analyzed by vertically dividing into quarters of the dislocated facet joint. The severity of the mIF injury was analyzed by dividing the subluxated articular surface facet into quarters. The degree of soft tissue injury was measured by magnetic resonance imaging and divided into three grades. The correlation between preoperative reducibility and other variables was analyzed.
Results
Group A contained 27 cases (DFI 2=21, DFI 3=6), and there were 23 cases in group B (nine partial reduction and 14 failures, DFI 2=13, DFI 3=9, DFI 4=1). In DFI 2, the more severe dislocation (D3 and D4), the higher the probability of reduction failure (p=0.001), and the probability of reduction failure increased with less subluxation (S1) (p=0.033). In DFI 3 and 4, the grade of dislocation (D4) also appeared to correlate with the reducibility (p=0.016).
Conclusion
The degree of facet involvement could be used as a diagnostic and therapeutic tool in treating DFI of the lower cervical spine. In particular, in DFI 2, severe dislocation (50% or more) or mild subluxation (25% or less), and 75% or more dislocation in DFI 3 and 4 may be a risk factor for interrupting closed traction reduction.

Keyword

cervical spine; distractive flexion injury; facet joint; joint dislocations; traction