Surgical approaches for cervical spine facet dislocations in adults

The choice of surgical approach for the management of subaxial cervical spine facet dislocations is a controversial subject amongst spine surgeons. Reasons for this include differences in the technical familiarity and experience of surgeons with the different surgical approaches, and variable interpretation of image studies regarding the existence of a traumatic intervertebral disc herniation and of the neurological status of the patient. Moreover, since the approaches are dissimilar, important variations are likely in neurological, radiographical and clinical outcomes.

To compare the effects (benefits and harms) of the different surgical approaches used for treating adults with acute cervical spine facet dislocation.

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (9 May 2014), The Cochrane Central Register of Controlled Trials (The Cochrane Library, 2014 Issue 4), MEDLINE (1946 to April Week 5 2014), MEDLINE In-Process & Other Non-Indexed Citations (8 May 2013), EMBASE (1980 to 2014 Week 18), Latin American and Caribbean Health Sciences (9 May 2014), trial registries, conference proceedings and reference lists of articles to May 2014.

We included randomised and quasi-randomised controlled trials that compared surgical approaches for the management of adults with acute cervical spine facet dislocations with and without spinal cord injury.

Two review authors independently selected studies, assessed risk of bias and extracted data.

We included one randomised and one quasi-randomised controlled trial involving a total of 94 participants and reporting results for a maximum of 84 participants. One trial included patients with spinal cord injuries and the other included patients without spinal cord injuries. Both trials compared anterior versus posterior surgical approaches. Both trials were at high risk of bias, including selection bias (one trial), performance bias (both trials) and attrition bias (one trial). Data were pooled for one outcome only: non-union. Reflecting also the imprecision of the results, the evidence was deemed to be of very low quality for all outcomes; which means that our level of uncertainty about the estimates is high.Neither trial found differences between the two approaches in neurological recovery or status, as shown in one study by small clinically insignificant differences in NASS (Northern American Spine Society) neurological scores (0 to 100: optimal score) at one year of follow-up: anterior mean score: 85.23 versus posterior mean score: 83.86; mean difference (MD) 1.37 favouring anterior approach, 95% confidence interval (CI) -9.76 to 12.50; 33 participants; 1 study). The same trial found no relevant between-approach differences at one year in patient-reported quality of life measured using the 36-item Short Form Survey physical (MD -0.08, 95% CI -7.26 to 7.10) and mental component scores (MD 2.88, 95% CI -3.32 to 9.08). Neither trial found evidence of significant differences in long-term pain, or non-union (2/38 versus 2/46; risk ratio (RR) 1.18, 95% CI 0.04 to 34.91). One trial found better sagittal and more 'normal' alignment after the anterior approach (MD -10.31 degrees favouring anterior approach, 95% CI -14.95 degrees to -5.67 degrees), while the other trial reported no significant differences in cervical alignment. There was insufficient evidence to indicate between-group differences in medical adverse events, rates of instrumentation failure and infection. One trial found that the several participants had voice and swallowing disorders after anterior approach surgery (11/20) versus none (0/22) in the posterior approach group: RR 25.19, 95% CI 1.58 to 401.58); all had recovered by three months.

Very low quality evidence from two trials indicated little difference in long-term neurological status, pain or patient-reported quality of life between anterior and posterior surgical approaches to the management of individuals with subaxial cervical spine facet dislocations. Sagittal alignment may be better achieved with the anterior approach. There was insufficient evidence available to indicate between-group differences in medical adverse events, rates of instrumentation failure and infection. The disorders of the voice and swallowing that occurred exclusively in the anterior approach group all resolved by three months. We are very uncertain about this evidence and thus we cannot say whether one approach is better than the other. There was no evidence available for other approaches. Further higher quality multicentre randomised trials are warranted.