Patient-Reported Outcomes and Plausible Prognostic Factors in Patients With Post-Traumatic Cervical Locked Facets; An Ambidirectional Cohort Study

Abstract

Background: Cervical facet dislocations occur rarely in the setting of cervical spinal trauma in general, accounting for about 5%-10% of all cases. Considerable controversy exists especially regarding plausible prognostic factors, outcome, and treatment options. We considered all cases of unilateral or bilateral cervical facet dislocations admitted to a single university-affiliated center, to search for common prognostic factors, measure outcome, and evaluate the safety and efficacy of current treatment strategy performed in our center.

Materials and Methods: In an ambidirectional cohort design, all cervical spinal trauma patients admitted to the only specialized trauma center affiliated to Shiraz University of Medical Sciences from Jan 2009 to May 2013 were evaluated.  All patients underwent thorough imaging studies, cervical traction, and surgery using a specific protocol. Patients' demographic, clinical, imaging and interventional data were retrospectively collected. Prospectively, patient's functional outcome as rated by the modified Japanese Orthopedic Association (mJOA) Scale score, residual pain as scored on visual analogue scale (VAS), and the status of fusion, alignment and hardware integrity on follow-up cervical radiographs were evaluated.

Results: A total of 28 patients were admitted, 19 (68%) were unilateral and 9 (32%) were bilateral. Mean age at trauma was 41.1 ± 16.1; there were 22 (79%) male and 6 (21%) female patients. Motor-vehicle accidents were the cause of trauma in the majority of patients (93%). C5-C6 was the most common (43%) level involved, followed by C6-C7 (26%). There was a significant trend for the bilateral locked facets to occur at lower cervical levels. Lower cervical levels were also associated with a higher rate of associated trauma or fracture at other cervical levels or other parts of the body. ULF patients were most commonly intact (63% AIS E); while BLF patients were mostly quadriplegic (56% AIS A) (p value = 0.016). Closed reduction was performed with a mean weight of 9 kilograms (range: 4 – 17), and it was successful in 82% of cases. Male patients (p value = 0.03) and BLF patients (p value = 0.002) needed significantly higher weights for reduction. Eighty-six percent of patients were operated in a single stage operation, and anterior approach was used more commonly. Single posterior approach was used more commonly in patients with BLF (p value = 0.02), and in lower cervical levels (p value = 0.007).  Only four patients required a second approach for a circumferential fusion. There were no surgery-related complications. The primary outcome parameter, total mJOA score was non-significantly higher in ULF (median: 18) than BLF (median: 9) patients, only the upper extremity motor and sphincter domains of the mJOA scale were significantly higher in ULF patients. Residual cervical pain at follow-up (sclaled on VAS) was not also different between two groups. The only predictor of outcome was neurological status of the patient on admission. There were only one long-term complication (mal-union and post-op kyphosis) in follow-up.

Conclusion: Facet fractures, especially when bilateral, can cause significant neurological morbidity. We may have to expect a more complicated course and a more extensive approach in cases of bilateral locked facets, or injury at lower cervical levels. Our treatment strategy is effective and safe in short-term; and despite limited follow-up, seems to be also effective in long-term.