Background: The anterior cervical fusion to treat symptomatic cervical disc herniations is well established with nearly 100% fusion rates. In the future, the philosophy of spine surgeons will be to undertake maintenance of motion when treating spinal segmental disease. However, the quality requirements for an arthroplasty device are one of the most challenging aspects. With respect to this issue, the M6-C artificial disc comes very close to the physiological cervical disc. The utilization of motion-preserving implants versus conventional instrumentation systems, which stabilize the operative segments, necessitates improved understanding of their comparative biomechanical properties and optimal biomechanical method for surgical implantation. The technique for anterior cervical arthroplasty using the M6-C (Spinal Kinetics, Sunnyvale, USA) cervical artificial disc is illustrated. Surgical positioning and the operative approach are demonstrated in detail. Our methods of retractor placement, surgical exposure, the technique used for decompression and preparation are discussed and presented in detail. Optimal arthroplasty device positioning is demonstrated. The surgical pitfalls of anterior cervical arthroplasty are highlighted.
Methods and Findings: Between January 2006 and March 2009 cervical artificial disc replacement has been performed in 55 patients. All the cases were operated according to the standard procedure for artificial disc replacement. Data were extracted from patient’s medical records, and the clinic’s electronic files. 4 patients have been reoperated; one patient was been reoperated due to problem related to the artificial disc, the patient had hyper-mobility of the operated level, the second one due to residual disc material. Within 7 months after surgery, 2 other patients were reoperated due to degeneration of the adjacent discs.
Conclusion: The device is safe, and the clinical outcomes have been excellent. Clinical and radiographic results are encouraging. Cervical arthroplasty procedures selected appropriately for the patient can optimize the patient’s opportunity for neurological improvement and faster recovery than anterior cervical fusion techniques and presumably can reduce the progressive process of adjacent level degeneration, however further clinical studies with larger sample sizes and long term outcome assessment will be required to show statistical benefits in preserving normal motion and decrease the incidence of adjacent level disease. Appropriate patient selection and attention to surgical technique, as described in this article, are very important to reduce complications and optimize patient benefit from cervical arthroplasty.