Cement leakage as a possible complication of balloon kyphoplasty—is there a difference between osteoporotic compression fractures (AO type A1) and incomplete burst fractures (AO type A3.1)?

Background Besides the treatment of osteoporotic vertebral compression fractures of AO type A1, balloon kyphoplasty (BKP) is seen as a therapeutic option even in the treatment of incomplete osteoporotic burst fractures (AO type A3.1). However, due to involvement of the posterior vertebral body wall, the risk of cement leakages is considered to be higher. This study focuses on the frequency and pattern of cement leakages in AO type A3.1 fractures compared with osteoporotic compression fractures (AO type A1). Patients and methods Retrospective cohort analysis was done of all patients (n = 138) treated by BKP for osteoporotic vertebral fractures (n = 173) between January 2007 and December 2010 in our department. Cement extravasations into three pre-defined anatomical compartments were evaluated on postoperative CT scans of the augmented vertebral bodies, with even minor cement detections beyond the vertebral body’s wall being strictly inidicated as leakages. The frequency of cement leakages in relation to the fracture type was statistically analyzed using Pearson's chi-square test. Clinical and radiological follow-up was done 6 weeks, 3 and 6 months postoperatively. Results The overall cement leakage rate of BKP in 173 treated osteoporotic vertebral fractures was 30.6%. Cement extravasations were detected in 20.3% of A1.1, 30.5% of A1.2, 37.8% of A1.3, and 39.0% of A3.1 fractures, respectively. There was no statistically significant difference in the leakage rate between A3.1 and all A1 fractures (28.0%; p > 0.05), but between A3.1 and A1.1 fractures (p