Abstract
Background Interbody fusion is a widely utilized and accepted procedure to treat advanced debilitating lumbar degenerative disc disease (DDD). Increasingly, surgeons are seeking interbody devices that are large for stability and grafting purposes but can be inserted with less invasive techniques. To achieve these contrary objectives a novel, conformable mesh interbody fusion device was designed to be placed in the disc space through a small portal and filled with bone graft in situ to a large size. This design can reduce the risk of trauma to surrounding structures while creating a large graft footprint that intimately contours to the patient’s own anatomy. The purpose of this Investigational Device Exempt (IDE) trial was to evaluate the perioperative and long-term results of this novel conformable mesh interbody fusion device.
Methods This investigation is a prospective, multicenter, single-arm, Food and Drug Administration and Institutional Review Board-approved IDE, performance goal trial. A total of 102 adults presenting with DDD at a single level between L2 and S1 and unresponsive to 6 months conservative care had instrumented lumbar interbody fusion. Validated assessment tools include 100 mm visual analog scale for pain, Oswestry Disability Index (ODI) for function, single question survey for patient satisfaction, and computed tomography (CT) scan for fusion. Patients were enrolled across 10 geographically distributed sites. Pain/ODI surveys, physical evaluations, and imaging were performed serially through 24 months. Specifically, CT was performed at 12 and, if not fused, 24 months. Independent radiologists assessed CTs for fusion. An independent committee adjudicated adverse events. Patients with complete data at 24 months were included in the analysis.
Results Ninety-six (96, 94% follow-up rate) patients (57.0 ± 12.0 years, 50.0% female, Body Mass Index 30.6 ± 4.9) reported average decreased low back pain from baseline of 45.0 ± 26.6 at 6 weeks and 51.4 ± 26.2 at 24 months. Right/left leg pain reduced by 28.9 ± 36.7/37.8±32.4 at 6 weeks and 30.5±33.0/40.3 34.6 at 24 months. Mean ODI improved 17.1 ± 18.7 from baseline to 6 weeks and 32.0 ± 18.5 by 24 months. At 24 months, 91.7% of patients rated their procedure as excellent/good. Fusion rates were 97.9% (94/96) at 12 months, and 99% (95/96) at 24 months. Mean operative time, estimated blood loss, and length of stay were 2.6 ± 0.9 hours, 137 ± 217 mL, and 2.3 ± 1.2 days, respectively. No device-related serious adverse events have occurred.
Conclusions Clinically significant outcomes for pain, function, fusion, and device safety were demonstrated in this population. Substantial clinical improvements occur by 6 weeks postoperative and continue to improve to 24 months. The successful outcomes observed in this trial support use of this novel device in an instrumented lumbar interbody fusion.
Level of Evidence 3.
Clinical Relevance This reports substantiates that the preliminary 1-year findings published earlier for this investigation are confirmed and the fusion rates and that patient improvements reported are sustained through 2 years.
- minimally invasive spine surgery
- degenerative spondylolisthesis
- lumbar interbody fusion
- transforaminal lumbar interbody fusion
- FDA study
- investigational device exemption
Footnotes
Funding Marcus Stone discloses support for the present article (eg, funding, provision of study materials, medical writing, etc) from Spineology. No other author(s) received financial support for the research, authorship, and/or publication of this article.
Financial Disclosures and Conflicts of Interest John Chi discloses consulting fees from DePuy Spine and Stryker/K2M. Pierce Nunley discloses royalties or licenses from Stryker, Zimmer Biomet, and IMSE; consulting fees from Spineology, Stryker, IMSE, Integrity Implants, Kuros, NEO Spine, and Simplify Medical; payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or education events from Instrinsic Therapeutics and Organogenesis; and stock or stock options from Spinelogy and Surgalign. Stephane Lavoie discloses royalties or licenses from Spineology and consulting fees from Choice Spine and Spineology. Yi Lu discloses grants from the Stepping Strong Foundation (paid to institution); consulting fees from DePuy/Synthes; and stock or stock options in AxioMed LLC. Marcus Stone discloses support for the present article (eg, funding, provision of study materials, medical writing, etc) from Spineology; grants or contracts from Wright Medical (paid to institution); consulting fees from Spineology and Organogenesis (paid to Marcus Stone) and from Simplify Medical, Zimmer Biomet, and Spineology (paid to institution). All remaining authors report no relevant disclosures.
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