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Axial vs. angular dynamization of anterior cervical fusion implants
Marin Stancić1, Petra Margetić, Esmat Elabjer
1Department of Neurosurgery, University Hospital Dubrava, School of Medicine, University of Zagreb, Zagreb, Croatia. marin.stancic@zg.t-com.hr
Collegium Antropologicum
|May 23, 2008
Summary
Anterior cervical fusion outcomes were similar across dynamic implants, H-plates, and non-augmented groups. However, dynamic implants showed faster fusion rates, while H-plates had higher rates of pseudoarthrosis.
Area of Science:
- Spine surgery
- Orthopedic implants
- Fusion techniques
Background:
- Anterior cervical fusion is a common procedure for radiculopathy and myelopathy.
- The efficacy of different implant augmentation techniques requires further investigation.
Purpose of the Study:
- To compare clinical and radiographic outcomes of anterior cervical fusion augmented with dynamic implants versus first-generation H-plates and non-augmented fusion.
- To evaluate fusion quality, dynamization, and complication rates associated with each technique.
Main Methods:
- Prospective cohort study of 81 patients undergoing neurodecompression for cervical radiculopathy/myelopathy.
- Patients were divided into three groups: dynamic implant augmentation (N=33), H-plate augmentation (N=33), and non-augmented (N=15).
- Clinical outcomes assessed using Nurick, Odom, and SF-36 scales; radiographic outcomes included screw rotation/translation and fusion quality (Tribus) at 6 weeks and 4 years.
Main Results:
- No significant differences in overall clinical outcomes between the three groups.
- Dynamic implants exhibited axial dynamization (2.67 mm translation), while H-plates showed angular dynamization (7.2 degrees rotation).
- Fusion quality at 6 weeks was significantly better in dynamic implant and non-augmented groups compared to the H-plate group. Complications included pseudoarthrosis (H-plate), heterotopic ossification (dynamic implants), and graft dislodgement (non-augmented).
Conclusions:
- Implant selection is not critical for achieving satisfactory clinical outcomes in anterior cervical fusion.
- Both dynamic and H-plate fixation systems allow for subsidence.
- Axially dynamized implants appear to facilitate faster and more effective fusion compared to other methods.
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