Object: To increase knowledge about unilateral facet dislocation, including presentation, radiological findings, management, and outcome, the authors reviewed the cases of 51 consecutive patients with unilateral locked facets of the cervical spine who underwent treatment over an 11-year period. With the development of internal fixation devices, the authors compared the procedure of using interspinous wire and facet wiring of iliac crest to fix unilateral locked facets with that in which interspinous braided cable and lateral mass plates were used.
Methods: Thirty-seven patients (73%) presented with radiculopathy, eight (16%) with neck pain only, and six (12%) with spinal cord injuries (SCIs). Plain x-ray films demonstrated subluxation in only 44 (86%) of 51 cases. All patients underwent cervical computerized tomography (CT) scanning, and in all patients with SCI, a magnetic resonance (MR) image was obtained. Fracture in addition to facet locking was seen on 24 (47%) of 51 CT scans. Disc disruption with cord compression was seen in five cases (10%). Based on CT and/or MR imaging findings, a closed reduction procedure was believed to be contraindicated in 11 cases (22%). Of the remaining 40 patients, 13 (33%) underwent closed reduction procedures. Two patients who underwent a closed reduction procedure were placed in a halo brace but experienced resubluxation. Thus, all cases were surgically treated. Forty-six patients underwent posterior reduction and/or internal fixation alone (in 24 cases spinous process fixation with facet wiring was connected to struts of iliac crest, and in 22 cases interspinous braided cable for lateral mass plating was used). Initial surgery, regardless of technique, was successful in 45 (98%) of 46 cases. One patient experienced a resubluxation and underwent reoperation in which anterior cervical fusion and plating were performed. Four of six patients with SCI underwent an emergency combined anterior-posterior decompressive procedure in which internal fixation was performed, and the patients experienced immediate neurological improvement. Overall there were no cases of neurological worsening or death, and there were three cases of wound infection. At 1 year postsurgery, all deficits had improved. Of 37 cases of radiculopathy, three patients (8%) experienced persistent 4/5 weakness, and the remaining patients were normal, including four patients in whom diagnosis was delayed. The six patients with SCI all improved significantly by 1 year. Persistent neck pain was seen in nine cases (18%). Although the lateral mass plates and interspinous cable are stronger, easier to place, and significantly lessened the amount of resultant kyphosis (p < 0.02), the results of chi-square analysis demonstrated only a slight trend for improved clinical outcome compared with the use of wire and iliac crest (p = 0.1).
Conclusions: Cervical CT and MR imaging provide information that aids in the diagnosis and management of patients with unilateral locked facets of the cervical spine. The authors' experience strongly suggests that a reduction procedure in which internal fixation and bone fusion are performed will be the most successful treatment for this injury.