Impact of the quantity of intradiscal cement leak on the progression of intervertebral disc degeneration.

Introduction We aim to assess the impact of the quantity of intradiscal cement leak during kyphoplasty on the rate of progression of degenerative changes in the affected disc. Methods Of 316 kyphoplasty procedures, we identified 32 episodes of intradiscal cement leak in 26 patients. The quantity of cement leaked was graded from I to IV. Disc degenerative changes were assessed at presentation and follow-up using radiographical scoring and magnetic resonance imaging (MRI) grading systems. Data for low-grade leaks (grade I) were compared with the medium- and high-grade leaks (grades II-IV) using a chi-squared test. Results Median follow-up radiographic and MRI assessments were made at 18 and 21 months, respectively. Medium- and high-grade leaks were associated with a significantly higher radiographic disc degeneration scores compared with low-grade leaks (P = 0.04295) but no difference was found in MRI disc degeneration grades and in adjacent vertebral fracture rates. Conclusions Our findings indicate that the quantity of cement leaking into the disc space significantly influences the rate of progression of disc degeneration.