椎体圧迫骨折に対するKIVAシステムとバルーン後弯症形成術の比較：ランダム化比較試験のメタアナリシス

Vertebral compression fractures (VCFs) are the most common type of vertebral body fracture. The Kiva VCF Treatment System is a relatively novel technique to manage VCFs. The aim of this study was to compare the efficacy of Kiva versus standard Balloon Kyphoplasty (BK) through evaluation of published randomized controlled trials (RCTs).

This study was performed following the guidelines for PRISMA. We performed a systematic literature search using PubMed and MEDLINE in June 2023. The search keywords were "Kiva" and "Kyphoplasty" which yielded a total of 112 articles. Outcome measures included pain, measured through the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI), and cement leakage rates.

Three RCTs were included in this meta-analysis. A total of 468 patients (Kiva=232 patients and BK=236 patients) and 694 fractures (351 treated with Kiva and 343 treated with BK) were included after fulfilling the inclusion criteria. The VAS score in both the Kiva and BK group improved significantly. There was no difference in VAS improvement between the 2 groups (p-value=.84). Of the 694 fractures that were treated procedurally, the Kiva system had significantly less cement leakage than BK (95% CI [-0.89, -0.22], p-value=.00). However, and collectively out of those who had cement leakage, there was only 2 patients (2.1%) developed adverse events of acute paraplegia required reoperation.

This meta-analysis demonstrates that the Kiva system and balloon kyphoplasty are both strong treatment options for the purpose of reducing pain associated with VCFs, whether osteoporotic or metastatic in etiology. However, Kiva system was favorable over balloon kyphoplasty in terms of rates of cement leakage.