[Effectiveness of cervical disc replacement for cervical myelopathy].

OBJECTIVE

To evaluate the effectiveness of cervical disc replacement for cervical myelopathy.

METHODS

Between October 2006 and October 2008, 20 patients (26 segments) with cervical myelopathy underwent single-level (14 segments) or bi-level (6 segments) cervical disc replacement. There were 8 males and 12 females with an average age of 46 years (range, 26-65 years). The disease duration ranged 2-18 months (mean, 7 months). The effectiveness was evaluated using visual analogue scale (VAS) score, cervical range of motion (ROM), and the Odom et al. criteria. Heterotopic ossification (HO), osteophyte formation, and prosthesis loosening were observed.

RESULTS

All incisions healed by first intention, with no severe complication. Twenty patients were followed up 30-48 months (mean, 34 months). At 28 months after operation, according to Odom et al, criteria, the results were excellent in 17 cases and good in 3 cases. The VAS scores of the neck, shoulder, and upper limb were significantly improved when compared with preoperative scores (P < 0.05). At 30 months after operation, X-ray films showed that 20 replaced segments were mobile and ROM was (10.6 +/- 4.5) degrees, showing no significant difference (P > 0.05) when compared with that of upper adjacent segment (10.8 +/- 3.7) degrees and lower adjacent segment (7.5 +/- 4.2) degrees. HO occurred in 10 cases (13 segments). No displacement, subsidence, or loosening occurred except 1 case of retrodisplacement of the prosthesis.

CONCLUSION

Cervical disc replacement can obtain good effectiveness. It can maintain normal cervical ROM and physiological curvature. But it needs further long-term follow-up to evaluate the function and the influence on the adjacent segments.