A novel classification of cement distribution patterns based on plain radiographs associated with cement filling rate and relevance to the clinical results of unipedicle vertebroplasty.

Introduction: Cement distribution pattern following unipedicle percutaneous vertebroplasty (UVP) for osteoporotic vertebral compression fractures (OVCFs) has been reported in association with clinical results. The present retrospective study aimed to classify the bone cement distribution types following UVP and investigate the differences in clinical efficacy and related complications.

Materials And Methods: We retrospectively reviewed the medical records of the patients with single-segment OVCFs who underwent UVP. Cement distribution patterns were divided into the diffuse, block, double band, and single band types according to the plain radiographs and further by cement filling rate (CFR) based on a three-dimension reconstruction of post-operative CT. The cutoff values of CFR were > 34% for the diffuse, block between 34 and 20%, and each band of the double or single band < 20%. Clinical efficacy and related complications were compared among the four cement distribution types 24 h after the operation and the last follow-up.

Results: A total of 155 patients with an average follow-up time of 20.3 months were included. The diffuse type included 26 patients; block, 87; double band, 18; and single band, 24. The VAS and ODI after operation improved significantly in all four groups. The diffuse and block types had similar clinical results. The clinical outcomes in the single band group were the poorest at the last follow-up. The patients with single band type also had the highest rates of body re-collapse and revision surgery for the index level.

Conclusion: Diffuse and block groups can better maintain the height of the vertebral body and reduce the risk of vertebral body recompression. The single band has the poorest results, and intraoperative immediate contralateral vertebroplasty was highly recommended.