CT-guided vertebroplasty in osteoprotic vertebral fractures: incidence of secondary fractures and impact of intradiscal cement leakages during follow-up.

The purpose of this study was to analyse the number and types of secondary fractures, and to investigate the impact of intradiscal cement leaks for adjacent vertebral fractures. Patients with osteoporotic vertebral fractures were treated with vertebroplasty. Results were documented and prospectively followed by means of computed tomography (CT) and magnetic resonance imaging. The frequency and the types of cement leakages were analysed from multiplanar CT images and secondary fractures were characterised as follows: (1) adjacent fracture in the immediate vicinity of an augmented vertebra; (2) sandwich fracture, fracture of an untreated vertebra between two vertebrae that had been previously augmented, and (3) distant fractures not in the vicinity of augmented vertebrae. A total of 385 osteoporotic vertebral fractures were treated in 191 patients (61 men, 130 women, age 70.7 +/- 9.7 years). The overall rate of cement leaks was 55.6%, including all leaks detectable by CT. Intradiscal leaks through the upper, the lower, and both endplates occurred in 18.2%, 6.8%, and 2.6%, respectively. In 39 patients (20.4%), a total of 72 secondary fractures occurred: 30 adjacent fractures in 23 patients (12.0%) with a time to fracture of 2 months [median; 1.0/4.0 months, first/third quartile (Q1/Q3)]; 11 secondary sandwich fractures in 11 patients (5.8%) after 1.5 months (median; 0.25/7.5 months, Q1/Q3); and 31 distant fractures in 20 patients (10.5%) after 5 months (median; 2.0/8.0 months, Q1/Q3). Ten of 30 adjacent fractures occurred in the presence of pre-existing intradiscal cement leaks and 20 where there was no leakage. Six of 11 sandwich fractures occurred in the presence of intradiscal leaks (five leaks in both adjacent disc spaces, one leak in the lower disc space) and five where there was no leakage. The rate of secondary adjacent and non-adjacent fractures is quite similar and there is no specific impact of intradiscal leakages on the occurrence of adjacent secondary fractures. Adjacent fractures occur sooner than distant secondary fractures. Sandwich fractures are associated with specific biomechanical conditions, with a 37.9% fracture rate in sandwich constellations.