483 - Initial Results from a Series of Vertebral Body Replacement Using Pati...

General Session: Spinal Innovation

Presented by: M. Colman - View Audio/Video Presentation (Members Only)

Author(s):

M. Colman(1), J.-E. Loret(2), E. Lioret(2)

(1) Rush University Medical Center, Chicago, IL, United States
(2) Hospital University Center, Neurosurgery, Tours, France

Abstract

Background: Anterior cervical corpectomy with fusion (ACCF) has been demonstrated as a good alternative to anterior cervical discectomy and fusion (ACDF) to treat cervical spondylotic myelopathy (CSM). However, the use of vertebral body replacement (VBR) cages is technically demanding, especially to adjust the size of the cage to the defect without compromising the endplate integrity increasing the risk of subsidence. Beside recent studies advocating the interest of the shape, size and design of an implant to achieve fusion and stability in cervical spinal diseases indications, 3D printing offering rapid and patient-specific manufacturing has emerged over the past years. Several materials and technologies can be used and clinical and radiological data are still sparse.

Purpose: To describe the process, from design to implantation, of patient-specific vertebral body replacement (VBR) using a poly ether ketone ketone (PEKK) 3D-printed implant and evaluate the early outcomes in cervical spondylotic myelopathy (CSM).

Study Design: This retro-prospective single-center study was approved by the French national ethic committee and authorities in March 2016, allowing to include retrospectively all patients since the first implantation in January 2015 and prospectively all patients after the approval.

Patient Sample: 12 patients underwent a patient specific UNiD 3D VBR surgery (3f/9m; mean age 64.2y).

Outcome Measures: Clinical

Outcomes: mJOA, VAS, EMS, NDI and radiological outcomes

Methods: Devices were designed according to patient anatomy and 3D printed in PEKK. All clinical and radiological data were collected prior to surgery and expected at routine postoperative intervals of 3, 12 and 24 months.

Results: Five patients underwent a single-level corpectomy (4 at C4, 1 at C5), and 7 a double-level corpectomy (2 at C4-C5 and 5 at C5-C6). Immediate postoperative imaging were collected for 8 patients before discharge, and 7 have reach a maximal follow-up of 6 months in average (1.5 to 12). According to surgeons, patient specific VBR offer an easier and safer surgery. The implant just falls into place with no adjustments. At last follow-up, anterior, posterior and medial heights were improved of 1.9mm, 1.7mm and 1.4mm respectively which represents an improvement of 4%, 4% and 5% respectively with no severe subsidence (>3mm) observed. Planning was achieved at 96.3% in average in terms of height restoration. Both C2C7 and corpectomy angles were maintained. EMS improved from 12.25 to 15.25, mJOA from 11.62 to 15.37 which represent recovery rates of 54.75% and 74.97% respectively. VAS neck and arm decreased from 6.63 to 3.25 and from 5.25 to 2.75 respectively. NDI decreased from 46.63% to 23.87%. No revision were reported.

Conclusion: This first study enables to demonstrate the feasibility and easiness to use a custom-made 3D-printed VBR implant in CSM treatment. This approach allows to reach good radiological and clinical outcomes associated with a great achievement rate advocating the concept of a patient-specific therapy. These encouraging results have now to be confirmed and fusion assessed at longer follow-up and with a larger cohort.