Preliminary Results Using A New Anterior Hybrid Cervical Plate System
The series is composed of 21 males and 30 females with a mean age of 45.8 years. There were 15 smokers in the group. All patients presented with symptoms of cervical myelopathy and/ or radiculopathy, and demonstrated radiographic nerve root and/or spinal cord compression at one or more cervical levels. Twentytwo patients underwent single level ACDF, 11 patients underwent single level corpectomy, 3 patients were treated with multilevel corpectomy without posterior instrumentation, 8 patients underwent multilevel ACDF without posterior instrumentatior4 and 7 patients were treated with 1 4 level corpectomy supplemented with posterior instrumentation. In all patients except one, fibular allograft was used in the fusion construct. Fusion was determined at followup by static and dynamic plain radiographs and was defined as: the absence of lucency around the graft, an increase in subchondral endplate sclerosis, bridging bone between the graft and endplates, and absence of movement on dynamic radiographs. Cervical lordosis was followed with a modified Cobb angle; the modified Cobb angle was measured on immediate postoperative films and compared to the measurement at follow up. Outcomes were assessed clinically using a 4 tiered outcome scale based on the Prolo system, and were rated as excellent, good, fair or poor.
The mean follow up interval for the patients was 7.6 months. Excellent or good outcomes were seen in 82 percent of patients; results were stratified by fixed, variable, and hybrid bone screw constructs, and no significant difference was found in clinical outcome by construct type (p<.05, paired t test). Osseous fusion was seen in 96 percent of the patients, with no difference in fusion by construct type (p<.05). The overall change in modified Cobb angle for all three types of constructs was 3.36 degrees of kyphosis, with no significant difference in Cobb angle change by construct type (p<.05). Complications included one episode of chronic wound drainage treated with intravenous antibiotics and one postoperative wound infection, which required reoperation and intravenous antibiotics.
Initial results indicate that the Atlantis (tm) cervical plating system provides fusion rates and clinical outcomes which are comparable to other locking anterior cervical plating systems. It also has the unique advantage of providing three types of bone screw constructs, which makes the system effective over the wide range of anatomic requirements presented in anterior cervical fixation.