Clinical and Radiographic Results of Indirect Decompression and Posterior Cervical Fusion for Single-Level Cervical Radiculopathy Using an Expandable Implant with 2-Year Follow-Up

Abstract

Indirect posterior cervical nerve root decompression and fusion performed by placing bilateral posterior cervical cages in the facet joints from a posterior approach has been proposed as an option to treat select patients with cervical radiculopathy. The purpose of this study was to report 2-year clinical and radiologic results of this treatment method. Patients who failed nonsurgical management for single-level cervical radiculopathy were recruited. Surgical treatment involved a posterior approach with decortication of the lateral mass and facet joint at the treated level followed by placement of the DTRAX Expandable Cage (Providence Medical Technology, Lafayette, California, United States) into both facet joints. Iliac crest bone autograft was mixed with demineralized bone matrix and used in all cases. The Neck Disability Index (NDI), visual analog scale (VAS) for neck and arm pain, and SF-12 v.2 questionnaire were evaluated preoperatively and 2 years postoperatively. Segmental (treated level) and overall C2-C7 cervical lordosis, disk height, adjacent segment degeneration, and fusion were assessed on computed tomography scans and radiographs acquired preoperatively and 2 years postoperatively. Overall, 53 of 60 enrolled patients were available at 2-year follow-up. There were 35 females and 18 males with a mean age of 53 years (range: 40-75 years). The operated level was C3-C4 ( = 3), C4-C5 ( = 6), C5-C6 ( = 36), and C6-C7 ( = 8). The mean preoperative and 2-year scores were NDI: 32.3 versus 9.1 ( < 0.0001); VAS Neck Pain: 7.4 versus 2.6 ( < 0.0001); VAS Arm Pain: 7.4 versus 2.6 ( < 0.0001); SF-12 Physical Component Summary: 34.6 versus 43.6 ( < 0.0001), and SF-12 Mental Component Summary: 40.8 versus 51.4 ( < 0.0001). No significant changes in overall or segmental lordosis were noted after surgery. Radiographic fusion rate was 98.1%. There was no device failure, implant lucency, or surgical reinterventions. Indirect decompression and posterior cervical fusion using an expandable intervertebral cage may be an effective tissue-sparing option in select patients with single-level cervical radiculopathy.

Posterior cervical fusion utilizing cages placed bilaterally in the facets for the treatment of the upper cervical adjacent segment disease in the elderly

“…One concern of posterior cervical cages is the potential to cause kyphosis. Several studies suggest that kyphosis does not occur with placement of the implants in the facet [4,20,7,3,17]. Overall and segmental spinal alignment were unchanged in this series.…”

Tissue-Sparing Posterior Cervical Fusion With Interfacet Cages: A Systematic Review of the Literature

“…Patient outcome was assessed with NDI in all studies, except for 3-which used NDI in addition to SF-12. 8,14,16 At 12-month follow-up, the earliest published series in the literature reported significant improvements in the NDI (64.9 to 16.3). Additionally, the SF-12 physical component score (PCS), and SF-12 mental component score (MCS) improved from 34.6 to 45.4 and from 40.7 to 51.4, respectively.…”

“…Four of the included studies included patient reported outcomes (71.4%). 8,14,16,17 One study was a purely radiographic study 12 (14.3%) and another study was an analysis of a medical device registry (14.3%). 13 All studies, except 2, were limited to single-level interventions.…”

“…Fusion was assessed in a majority of the studies 8,14,16,17 ; however, the methods of radiographic fusion assessment were quite varied. Fusion was either assessed by computed tomography (CT) scans at 1 year or flexion-extension radiographs at final follow-up.…”

“…Fusion by CT was determined by the presence of bridging bone across the facet joint surface or the overlying lateral masses on sagittal reconstructions. 8,14,16,17 Fusion by flexion-extension radiographs was assessed by translational motion <2 mm, 8,14,16 interspinous distance <2 mm, 8,14,16,17 and/or angular range of motion <5 . 8 There was strong consistency of fusion based on CT imaging across the majority of included studies.…”