[PRELIMINARY EFFECTIVENESS OF POLYAMINOACID/NANO-HYDROXYAPATITE/CALCIUM SULFATE CAGE IN LUMBAR FUSION SURGERY].

OBJECTIVE: To discuss the early effectiveness of polyaminoacid/nano-hydroxyapatite/calcium sulfate (PAA/HA/CS) Cage (PHC Cage) in lumbar fusion surgery.

METHODS: Thirty cases undergoing lumbar fusion of single segment between March and September 2014 were enrolled in this study. The patients were randomly divided into the trial group (n = 20) and the control group (n = 10). The PHC Cage was implanted in the trial group, while the polyetheretherketone (PEEK) Cage was implanted in the control group. The patients of 2 groups mainly presented lumbocrural pain and lower limb radiation pain or numbness. There was no significant difference in gender, age, type, affected segment, disease duration, preoperative intervertebral height, the lordosis angle of fusion segments, and the Oswestry Disability Index (ODI) between 2 groups (P > 0.05). Lateral lumbar X-ray films and three dimensional CT were taken preoperatively and at 1 week and 3, 6, and 12 months postoperatively. The intervertebral height and the lordosis angle of fusion segments at 1 week and 3, 6, and 12 months after operation and ODI at 3, 6, and 12 months after operation were measured; and the bone graft fusion rate was evaluated according to Brantigan criteria.

RESULTS: There was no significant difference in operation time, intraoperative blood loss, and the amount of autologous blood transfusion between 2 groups (P > 0.05). Healing by first intention as obtained in 30 cses. All patients were followd up 12 months. The intervertebral height of fusion segments, the lordosis angle of fusion segments, and ODI at each time point after operation were significantly improved when compared with preoperative ones (P < 0.05). The ODI showed significant difference between 3 months and 6, 12 months (P < 0.05), but there was no significant difference between the other time points after operation (P > 0.05). There was no significant difference in the intervertebral height and the lordosis angle of fusion segments between groups at different time points (P > 0.05). There was no significant difference in the above indexes between the trial group and the control group at each time point (P > 0.05). At last follow-up, 5 cases were rated as Brantigan grade E, 13 cases as grade D, and 2 cases as grade C in the trial group; 4 cases were rated grade E, 5 cases as grade D, and 1 case as grade C in the control group. The bone fusion rate was 90% in 2 groups.

CONCLUSION: The PHC Cage can effectively restore and maintain the disc height of fusion segment, normal sequence and biomechanical stability of the lumbar spine. The PHC Cage is similar to the PEEK Cage and has good clinical outcome in short-term follow-up.