Fusion and failure following anterior cervical plating with dynamic or rigid plates: 6-months results of a multi-centric, prospective, randomized, controlled study

Abstract

Anterior cervical plate fixation is an approved surgical technique for cervical spine stabilization in the presence of anterior cervical instability. Rigid plate design with screws rigidly locked to the plate is widely used and is thought to provide a better fixation for the treated spinal segment than a dynamic design in which the screws may slide when the graft is settling. Recent biomechanical studies showed that dynamic anterior plates provide a better graft loading possibly leading to accelerated spinal fusion with a lower incidence of implant complications. This, however, was investigated in vitro and does not necessarily mean to be the case in vivo, as well. Thus, the two major aspects of this study were to compare the speed of bone fusion and the rate of implant complications using either rigid-or dynamic plates. The study design is prospective, randomized, controlled, and multi-centric, having been approved by respective ethic committees of all participating sites. One hundred and thirty-two patients were included in this study and randomly assigned to one of the two groups, both undergoing routine level-1-or level-2 anterior cervical discectomy with autograft fusion receiving either a dynamic plate with screws being locked in ap -position (ABC, Aesculap, Germany), or a rigid plate (CSLP, Synthes, Switzerland). Segmental mobility and implant complications were compared after 3-and 6 months, respectively. All measurements were performed by an independent radiologist. Mobility results after 6 months were available for 77 patients (43 ABC/34 CSLP). Mean segmental mobility for the ABC group was 1.7 mm at the time of discharge, 1.4 mm after 3 months, and 0.8 mm after 6 months. For the CSLPgroup the measurements were 1.0, 1.8, and 1.7 mm, respectively. The differences of mean segmental mobility were statistically significant between both groups after 6 months (P = 0.02). Four patients of the CSLP-group demonstrated surgical hardware complications, whereas no implant complications were observed within the ABC-group (P = 0.0375). Dynamic plate designs provided a faster fusion of the cervical spine compared with rigid plate designs after prior spinal surgery. Moreover, the rate of implant complications was lower within the group of patients receiving a dynamic plate. These interim results refer to a follow-up period of 6 months after prior spinal surgery. Further investigations will be performed 2 years postoperatively.

Outcome evaluation of zero-profile implant compared with an anterior plate and cage used in anterior cervical discectomy and fusion: a two-year follow-up study

“…Surgeons also prefer to add an anterior plate to enhance rigidity of fixation especially in multi-level cases (11,23,24). Although the design of the current anterior plate has been improved over the years, the complications related to the plates are still not rare, and include screw loosening or breakage, plate breakage, and screw pullout with or without migration into the gastrointestinal tract (15,25).…”

Techniques for anterior cervical decompression for radiculopathy

“…This study was scored Class III because of unblinded outcome observation, lack of reliability testing for the questionnaire, and the fact that any patients lost to follow-up were replaced. 30 Stulik et al 32 reported on 132 patients who underwent dynamic (69 patients) or rigid (63 patients) plate fixation for 1-or 2-level cervical surgery. The authors used dynamic radiographs to assess instability at 3 and 6 months postoperatively.…”

“…This study was scored Class III because of poor follow-up (58%) and lack of details on randomization or allocation concealment. 32 …”

New Surgical Technique to Secure the Bone Strut During Anterior Cervical Corpectomy and Fusion: Kusabi Fixation Technique -Technical Note-

“…The surgical outcomes with the anterior plate technique are acceptable, but various hardware-related complications have been reported, including oblique plate, migration of the plate, and/or back out of screws, in more than 30% of cases. 1,[4][5][6]8) One of the most serious complications of hardware failure is esophageal violation. 2,3,6,7) The implanted hardware should be removed after confirmation of solid bone fusion, but compliance seems to be low because of complications caused by reoperation through the anterior approach.…”