59 - Initial Results of a Multi-center Study of the InterCushion Disc Nucle...

#59 Initial Results of a Multi-center Study of the InterCushion Disc Nucleus Replacement

Oral Posters: Cutting Edge

Presented by: P. De Muelenaere

Author(s):

P.F.R.G. De Muelenaere (1)
J. Hurlbert (2)
P. Asdourian (3)
A. Schwartz (4)
J.C. Felt (5)

(1) Brandon Regional Health Authority, Department of Surgery, Brandon, MB, Canada
(2) University of Calgary, Department of Clinical Neurosciences, Calgary, AB, Canada
(3) Greater Chesapeake Orthopaedic Associates, Baltimore, MD, United States
(4) Orthopedic SpineCare of Long Island, Huntington Station, NY, United States
(5) Vertebral Technologies Inc., Minnetonka, MN, United States

Abstract

Introduction: Degeneration of the disc nucleus is typically the condition that starts the process of spine degeneration. Disc Nucleus Prostheses (DNPs) to replace the desiccated nucleus pulposus have been developed in the past but these have been limited in their effectiveness by migration and subsidence issues.

Objective: Purpose of this study is to evaluate safety and efficacy of the InterCushion™ DNP (Vertebral Technologies, Inc. Minnetonka, MN).

Methods: This is a prospective, non-randomized Health Canada regulated pilot study. To date 13 patients have been implanted from a target number of 100. The device is intended for skeletally mature patients with leg pain due to a herniated disc with or without back pain indicated for a discectomy at one level from L2-S1. Patients must have a minimum Oswestry Disability Index (ODI) score of 40% and a minimum leg pain score of 6cm on a 10cm Visual Analog Score (VAS). These patients should have no spondylolisthesis at the involved level. Patients should be aged 21 to 60 and should have a BMI not exceeding 32. Data are collected pre-operatively and at 2 and 6 weeks, 3, 6, 12 and 24 months post-operatively.

The InterCushion consists of a number of individually-molded, polyurethane modules that can be assembled within the disc space via an interlocking design to form a single contiguous structure. Each section has a width of less than 10mm to minimize the size of the access channel through the annulus fibrosus and amount of bone that must be removed for implantation via the posterior approach. The implant is available in heights of 7, 8, 9, & 10mm, and anterior / posterior lengths of 16, 18, & 20mm. The number of modules used determines the overall medial / lateral width of the implant (4 modules = 23mm, 5 modules = 28mm). Dedicated instruments were developed to enable the minimally invasive implant procedure.

Results: 13 patients (11 male, 2 female) have been implanted with the InterCushion. Average age of the patients was 34.1 years, (22-58) and average BMI was 24.85 (22-31). Two patients were explanted due to non-device related, peri-operative surgical issues (destruction of the lateral annular wall and dural tear).

We report on the 11 patients who have the InterCushion implanted and continue to be followed. Average ODI improved from 48% ± 15% at baseline (N=11) to 31% ± 16% at 2 weeks (N=11), 9% ± 7% at 3 months (N=7) and 3% ± 2% at 12 months (N=6). Back VAS improved from an average score of 6.5 ± 2.9 pre-op (N=11) to 1.7 ± 1.4 at 2 weeks (N=11), 0.8 ± 0.7 at 3 months (N=7) and 0.5 ± 1.2 at 12 months (N=6). Leg VAS improved from an average of 7.2 ± 1.1 at baseline (N=11) to 1.1 ± 1.4 at 2 weeks (N=11), 1.0 ± 0.8 at 3 months (N=7) and 0.0 ± 0.0 at 12 months (N=6).

Conclusions: This pilot study demonstrates good early clinical outcomes for patients treated with the InterCushion DNR. Continued follow-up is required to determine the long term safety and efficacy of the InterCushion device.

Caution: Investigational device. Not for sale in the U.S.