Abstract
INTRODUCTION
Over 85% of patients with multiple myeloma (MM) have bone disease, mostly affecting thoraco-lumbar vertebrae. Vertebral fractures can lead to pain and large spinal deformities requiring application of vertebroplasty (PVP). PVP could be enhanced by use of Coblation technique to remove lesions from compromised MM vertebrae prior to cement injection (C-PVP).
METHODS
28 cadaveric MM vertebrae, were initially fractured (IF) up to 75% of its original height on a testing machine, with rate of 1mm/min. Loading point was located at 25% of AP-diameter, from anterior. Two augmentation procedure groups were investigated: PVP and C-PVP. All vertebrae were augmented with 15% of PMMA cement. At the end of each injection the perceived injection force (PIF) was graded on a 5-point scale (1 very easy to 5 almost impossible). Augmented MM vertebrae were re-fractured, following the same protocol as for IF. Failure load (FL) was defined as 0.1% offset evaluated from load displacement curves.
RESULTS
Mean initial FL was 2.5kN (STD=1.8kN) and 2.7kN (STD=1.8kN) for PVP and C-PVP, respectively. Mean augmented FL was 3.5kN (STD=3.1kN) and 4.2kN (STD=2.3kN)for PVP and C-PVP, respectively. Only the effect of augmentation was significant(p=0.006). Median PIF on the RIGHT side of vertebrae was 3.0 in PVP group and 2.5 in C-PVP (p=0.054). On the LEFT side it was 3.5 in PVP group and 3.0 in C-PVP (p=0.028).
DISCUSSION
Results suggest that Coblation did not compromise strength of augmented MM vertebrae. The PIF was lower for C-PVP, as compared to PVP group, probably due to removal of lesion tissue.
