Anterior cervical discectomy and fusion with structural allograft and plates for the treatment of unstable posterior cervical spine injuries
Authors: Woodworth Richard S. , Molinari William J. , Brandenstein Daniel , Gruhn William , Molinari Robert W. 
Published: February 2011

Object
The purpose of this study was to evaluate complications and radiographic and functional outcomes of isolated anterior stabilization surgery in which structural allograft and plates were used for posterior unstable subaxial cervical spine lateral mass, facet, and ligamentous injuries.

Methods
Between August 2003 and January 2008, 19 consecutive patients with unstable lateral mass, facet, and/or posterior ligamentous injuries of the subaxial cervical spine were treated by a single surgeon via an anterior approach. This was performed using structural allograft and plate fixation. Patients with any associated anterior vertebral fractures were excluded from the study. Autogenous bone grafts or bone graft substitutes were not used in any patient. The average age of the patients was 43 years (range 17–87 years) and the mean follow-up period was 20.4 months (range 6–48 months). Seventeen of the 19 patients participated in the study; the other 2 were lost to follow-up. Operative times, estimated blood loss, length of hospital stay (LOS), and perioperative complications were recorded for each patient. Radiographic outcomes included fusion scores and sagittal alignment measurements. Outcome scores with respect to neck pain, satisfaction with surgery, and function were recorded for each patient according to analog pain and satisfaction scales and the Neck Disability Index (NDI). Additionally, NDI and pain scores at final follow-up were compared with a group of healthy, age-matched controls.

Results
The average surgical time was 60 minutes (range 28–108 minutes), and the estimated blood loss averaged 48.9 ml per surgical procedure (range 20–150 ml). The LOS for the 13 patients who had no other associated injuries averaged 2.2 days (range 2–3 days). Fifteen of 17 patients achieved solid radiographic fusion, and no patient demonstrated instability. Only 1 patient had significant loss of the initial sagittal alignment correction at final follow-up. The average NDI score for the 17 patients was 6.5 (range 0–11), indicating mild disability and comparing favorably to a group of healthy age-matched controls. There was no statistical difference in pain scores for the trauma patients and control group at ultimate follow-up (1.5 vs 0.3, respectively). Satisfaction scores for the 17 trauma patients were high, averaging 94% (range 80–100%). Ten of the 11 patients with preoperative radiculopathy demonstrated complete resolution of this condition. Complications occurred in 1 patient with transient hoarseness and 1 with transient swallowing difficulty. There were no wound complications. Screw breakage occurred in 1 patient, and an additional patient required revision surgery for pseudarthrosis.

Conclusions
Anterior cervical discectomy and fusion performed using interbody structural allograft and plate fixation is highly effective in the treatment of unstable posterior cervical lateral mass, facet, and ligamentous injuries. This treatment option results in low intraoperative blood loss, short operating times, and a brief LOS. Radiographic outcomes with respect to segmental stability are excellent, and fusion rates with the use of structural allograft alone are high. Outcomes with respect to pain, function, and patient satisfaction are high, and complications are acceptably low.