Article

Vertebral compression fracture repair aims to relieve pain and
improve function by restoring vertebral structure and biomechanics, but is still
associated with risks arising from polymethylmethacrylate cement extravasation.
The Kiva(R) Vertebral Compression Fracture Treatment System, a stacked coil
implant made of polyetheretherketone and delivered over a guide-wire, is a novel
device designed to provide height restoration and mechanical stabilization, while
improving cement containment and minimizing disruption of cancellous bone. The
objective of this study was to determine whether the Kiva system is as effective
as balloon kyphoplasty at restoring mechanical properties in osteoporotic
vertebral compression fractures. METHODS: Wedge fractures were created in the
middle vertebra of fourteen osteoporotic three-vertebra spine segments and then
repaired with either the Kiva or kyphoplasty procedure. Height, stiffness and
displacement under compression of the spine segments were measured for four
conditions: intact, fractured, augmented, and post-cyclic eccentric loading
(50,000cycles, 200-500N, 30mm anterior lever arm). FINDINGS: No significant
differences were seen between the two procedures for height restoration,
stiffness at high or low loads, or displacement under compression. However, the
Kiva System required an average of 66% less cement than kyphoplasty to achieve
these outcomes (mean 2.6 (SD 0.4) mL v. mean 7.5 (SD 0.8) mL 0; P<0.01).
Extravasations and excessive posterior cement flow were also significantly lower
with Kiva (0/7 v. 4/7; P<.05). INTERPRETATION: Kiva exhibits similar
biomechanical performance to balloon kyphoplasty, but may reduce the risk of
extravasation through the containment mechanism of the implant design and by
reducing cement volume.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS