Thomas Josef Vogl MD, PhD, Presenter: Nothing to Disclose

Johannes E. G. Hierholzer MD, Abstract Co-Author: Nothing to Disclose

Robert Pflugmacher, Abstract Co-Author: Nothing to Disclose

Matthew J. Gounis PhD, Abstract Co-Author: Research Consultant, Johnson & Johnson Research Consultant, Micrus Corp Research grant, Stryker Corporation Research grant, Johnson & Johnson Research grant, Surpass Medical Ltd Research grant, Covidien AG Research grant, Concentric Medical, Inc Research grant, sanofi-aventis Group Research grant, Neuravi Limited Research grant, Neurointerventional Therapeutics, Inc Research grant, Thrombolytic Science LLC

Ajay Kumar Wakhloo MD, PhD, Abstract Co-Author: Research Consultant, Johnson & Johnson Research grant,Johnson & Johnson Stockholder, Surpass Medical Ltd Research Consultant, Koninklijke Philips Electronics NV Research grant, Koninklijke Philips Electronics NV Research Consultant, Boston Scientific Corporation Research grant, Boston Scientific Corporation Research Consultant, Soteira, Inc Research grant Covidien Research Consultant, Covidien

Christian Fiebig, Abstract Co-Author: Nothing to Disclose

Renate Maria Hammerstingl MD, Abstract Co-Author: Nothing to Disclose

A cement-directed kyphoplasty system (CDKS) was developed to provide directional control of cement flow during treatment of vertebral compression fractures. The goal of the procedure is to deliver cement into the anterior region of the vertebral body (VB), extending across the sagittal midline and towards the endplates. Posterior flow is minimized to reduce the risk of leakage into the venous system and spinal canal

A randomized (2:1) controlled study was performed comparing CDKS and bipedicular vertebroplasty (PVP). The CDKS procedure used a unipedicular approach with a combined curved drill and reamer to create a cylindrical cavity. The cement directing implant was inserted in a collapsed state, self-expanding to conform to the cavity. Cement was injected into the cement director, which guided flow into the anterior cancellous bone and restricted cement flow from the posterior VB. A total of 49 patients (65 levels) were treated with CDKS and 28 patients (39 levels) with PVP. Pain was assessed post-op, at 3 and 12 mos. using a 10-point visual analog scale (VAS). Vertebral body height was also compared at post-op and 3 mos. Radiographic and CT images taken at 3 mos. and 12 mos. were examined for adjacent level fractures.

Pain relief was equivalent for both treatment groups. A significant decrease in VAS scores was measured at post-op for both groups and pain relief was sustained throughout the follow-up period (p<0.001 for all comparisons). The mean change in VB height between post-op and 3 mos. was -4.00% (±8.52) and -9.42% (±8.28) for CDKS and PVP, respectively. Two adjacent level fractures were noted in the CDKS group (3.1%) and 3 were found in the PVP group (7.9%). None of the adjacent level fractures were related to endplate leaks.

CDKS provides control of cement placement and delivery, directing cement flow anteriorly and towards the superior and inferior endplates. Pain relief is equivalent to PVP. The procedure does not compromise the endplates or influence adjacent level fracture rates. The cement director limits posterior cement flow, reducing the risk of complications due to cement leakage.  

CDKS provides effective pain relief for vertebral compression fractures. The resulting endplate-to-endplate cement distribution maintains VB height without affecting adjacent level fracture rates.

Vogl, T, Hierholzer, J, Pflugmacher, R, Gounis, M, Wakhloo, A, Fiebig, C, Hammerstingl, R, Clinical Evaluation of Cement-directed Kyphoplasty System: Multicenter Trial.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11011195.html