Analysis of Adjacent Fractures after Two-Level Percutaneous Vertebroplasty: Is the Intervening Vertebral Body Prone to Re-fracture?

STUDY DESIGN: Retrospective study. PURPOSE: This retrospective study aimed to determine the incidence of adjacent level new fractures in a sandwich constellation (one or two untreated vertebrae between two cemented vertebrae) compared with that in other constellations formed by two-level percutaneous vertebroplasty (PVP). It also aimed to investigate the potential factors contributing to adjacent new fractures in a sandwich constellation. OVERVIEW OF LITERATURE: There are few studies regarding the intervening intact vertebral body between two cemented vertebrae. Clinical data from previous studies investigation this sandwich situation, too, have been vague. METHODS: Clinical data were obtained from 132 patients who had two cemented vertebral bodies, irrespective of whether they had undergone one or two PVP sessions between January 2013 and June 2016 at a single institution. Cases with one or two intact vertebral levels between the two cemented vertebrae were classified into group 1 (n=47), and cases with two consecutive cemented bodies or more than three levels of intervening configurations were classified into group 2 (n=85). Demographic data and radiological parameters for new fractures after PVP were compared between the two groups, and the rates of subsequent adjacent fractures were investigated. RESULTS: The incidence of single-level sandwich constellations was quite uncommon (7.7%). The overall incidences of adjacent fracture were 29.8% (14/47) in group 1 and 14.1% (12/85) in group 2. This difference was statistically significant (p =0.03). Approximately 80% (11/14) of the adjacent new fractures in group 1 developed at an intervening level. The patient demographics and radiological parameters for subsequent fractures after PVP did not statistically correlate with the risk of adjacent new fractures in group 1. CONCLUSIONS: Because they were subjected to double-load shifts, sandwich constellations were prone to re-fractures after PVP. These vertebral configurations required more aggressive management for osteoporosis.