Early-onset Adjacent Vertebral Fractures after Balloon Kyphoplasty and SpineJack® Kyphoplasty for the Management of Single-level Thoracolumbar Vertebral Compression Fractures.

Objective: To evaluate the risk factors contributing to early-onset adjacent level fractures (ALFs) occurring within 1 month following either balloon kyphoplasty (BKP) or SpineJack® kyphoplasty (SJ) for the treatment of thoracolumbar vertebral compression fractures (TLVCFs).

Materials and methods: This retrospective analysis enrolled patients with single-level TLVCFs (T11-L2) who underwent either BKP or SJ between July 2013 and June 2019. We recorded the ALF occurrences within 1 month. Age, osteoporosis, severity and shape of TLVCFs, and surgical type were compared between patients with and without early-onset ALFs.

Results: Altogether, 106 TLVCF patients were enrolled, comprising 64 BKP and 42 SJ cases. We observed 19 early-onset ALFs, with 9 and 10 cases in the BKP and SJ, respectively. Patients with early-onset ALFs have significantly more severe TLCVFs (severe versus mild, 25% versus 0%, p = 0.055) and wedge-shaped TLVCFs (26.47% versus 2.63%, p = 0.002) and older age (81.05 versus 73.34 years, p < 0.001) and kyphoplasty performed within 1 month are risk factors of early-onset ALFs (26.92% versus 9.26%, p = 0.018). Univariable analysis showed that kyphoplasty timing within 1 month (odds ratio [OR]: 0.193, p = 0.008), wedge-shaped TLVCFs (OR: 5.358, p = 0.036), and advanced age (OR: 1.119, p = 0.001) are significant risk factors of early-onset ALFs.

Conclusions: The occurrence rate of early-onset ALFs between BKP or SJ techniques in treating TLVCFs does not differ. Preoperative wedge-shaped TLVCFs, advanced age, and early treatment within 1 month are the risk factors of early-onset ALFs following kyphoplasty for TLVCFs.