The anterior approach to the cervical spine for discectomy and fusion by the insertion of an autologous iliac-crest tricortical bone graft was originally introduced by Robinson and Smith in 1955. In 1958, Cloward described a wide anterior cylindrical discectomy performed with a special reamer combined with anterior fusion by the insertion of autologous iliac bone graft of the same shape.

Nowadays, several implants are available on the market to perform anterior interbody fusion. Cages of different shapes and materials, which can be implanted with or without the need for additional anterior plating (Fig. 6.4). The cage size must be determined intraoperatively, under fluoroscopic control, using available trials. Use of allograft avoids the need for autograft harvesting, that produces significant morbidity to the donor site (i.e. iliac crest, fibula). Thus, authors prefer the use of bone bank allograft, but autograft can be easily obtained from the iliac crest too.

ACCF has been proven to be an effective technique in case of ventral compression posterior to the vertebral body (i.e., trauma, degenerative disease, infection, tumor; Fig. 6.5).

Moreover, cervical kyphotic deformities (especially if fixed on flexion-extension films) generally require an anterior approach, since posterior-only decompression would not allow the spinal cord to migrate posteriorly and symptoms are likely to continue postoperatively.

Furthermore, an anterior approach resolves compression on the anterior spinal artery that supplies up to 75–80% of the anterior spinal cord. Accurate collection of the medical history of the patient and a detailed physical examination are always mandatory and should be verified with advanced imaging modalities (MRI is the gold standard).

Anterior column (vertebral bodies and discs) is exposed through an anterior prevascular exposure, and the level is identified using intraoperative fluoroscopic control. Surgical field must be large enough to include the disc above and below the targeted vertebral body.

Then, discectomies at the levels above and below are performed as previously described.

After the discectomies have been performed, two longitudinal grooves, parallel to the uncinate processes and as deep as the anterior two thirds of the vertebral body, are made using a high-speed burr.

The central bone between the grooves is removed with a rongeur and stored for grafting. Then, the posterior wall of the vertebral body is thinned using a high-speed burr and later removed with Kerrison rongeurs along with the PLL. Finally, the decompression is accomplished removing any eventual osteophyte left.

Corpectomy defect can be reconstructed with various techniques, but proper size and appropriate positioning of the implant is cornerstone as the choice of reconstruction. After implant positioning, an anterior cervical plate is applied to stabilize the construct and prevent ventral migration.

Technical options for anterior column reconstruction:

Variables to take into consideration when selecting the technique:

Multilevel ACCF may lead to iatrogenic instability of the cervical spine, and therefore supplemental posterior fixation must be considered (Fig. 6.7). Generally, a supplemental posterior fixation is necessary when more than three levels are involved anteriorly.

Posterior fixation with respect to the sagittal balance of the cervical spine significantly decreases the risk of complications such as pseudarthrosis, graft failure, progressive kyphotic deformity, and plate dislodgement. Regardless of the number of levels involved, poor bone quality or an unstable anterior fixation should be always supported posteriorly.

In order to achieve secondary long-lasting stability with a solid fusion, decortication and grafting are recommended.

Anterior cervical plate has double biomechanical behavior depending on the applied forces; in fact, it acts as a tension band in extension and as a buttress plate in flexion.

Its use was initially meant to avoid graft dislodgement and/or subsidence.

First generation implants where nonconstrained load-sharing plates which required bicortical screw purchase in order to avoid excessive motion at the screw-plate interface and decrease screw loosening. Thus, engagement of the posterior vertebral cortex was technically challenging due to the risk of neurologic injury.

Then, constrained systems (static plates) that firmly lock the screws to the plate were developed. Securing the screws to the plates allows a more direct transfer of the applied forces from the spine to the plate and improved construct stiffness without the need for bicortical screw purchase.

Rigidly locked screw-plate systems theoretically expose the anterior column to potential stress shielding. Thus, dynamic semiconstrained plates were designed allowing for degree of load sharing between the plate and the spinal column (screw rotation, translation, or plate shortening).