OptiMesh® for Lumbar Interbody Fusion Trial (OLIF)

Seventy-six thousand posterior interbody fusions are performed annually in the U.S., and it has been estimated that at least 50% of those cases include supplemental posterior instrumentation. For interbody fusion with posterior fixation, spine surgeons currently place structural intervertebral spacers into the interbody space. These spacers may be pre-shaped devices constructed of allograft (cortical bone dowels or femoral rings) or non-metallic, radiolucent materials, or metallic cage devices. Autogenous bone graft and blood components (marrow, blood) are often added.

Use of morselized bone graft in orthopedic procedures is desirable because it is more rapidly incorporated during the course of bone healing. If the morselized graft pack can be effectively contained in the interbody space, the graft material can function as a structural spacer to provide anterior column support. Contained graft material can be tightly packed within the mesh to increase the graft's compressive strength. Unlike pre-shaped cortical grafts, the morselized pack conforms intimately to the host bone at the surgical site, ensuring good vascularization potential and reducing the osteoblast jumping distance for osteogenesis. In addition, the solidly packed graft retains intra-pack porosity, ensuring an osteoconductive scaffold to facilitate vascular and bony ingrowth.

It would be desirable to minimize autograft use because of associated post-op pain, to optimize contact between allograft and host bone, and to permit the surgeon to place or construct an effective structural intervertebral spacer with only minimal neural retraction required.

OptiMesh 1500S is intended to be used to contain the bone graft placed by spine surgeons into the interbody space to achieve spinal intervertebral body fusion. OptiMesh 1500S enables the use of morselized bone graft materials in spine fusion procedures instead of solid allograft materials, such as cortical bone dowels or femoral rings, or rigid synthetic materials.

In addition, the OptiMesh instrument system allows the surgeon to perform an interbody fusion through a small portal and to complete the entire fusion procedure from a posterior approach instead of a 360 degree anterior/ posterior procedure, which is often the case with the use of cages. The minimal access portal utilized for OptiMesh filling allows the device to be placed via a unilateral transforaminal or translaminar approach, versus the often-used bilateral approach required for many cages and cortical spacers. This flexibility permits the surgeon to adapt the surgical approach to the local anatomy of the patient.

Inclusion criteria

• Skeletally mature and be at least 18 years of age
• Have degenerative disc disease (DDD) requiring one level fusion between L2 and S1, with DDD confirmed by subject history, physical exam, and radiographic studies with one or more of the following factors:

• instability as defined by >3 mm translation or ≥5º rotation of flexion/ extension;
• osteophyte formation of facet joints or vertebral endplates;
• decreased disc height, on average 2 mm, but dependent on spinal level;
• scarring/thickening of the ligamentum flavum, annulus fibrosis, or facet joint capsule;
• herniated nucleus pulposus;
• facet joint degeneration/changes; and/or
• vacuum phenomenon;
• Based on the VAS, subjects report pre-operative low back pain (>4 of 10) with duration of pain six-months or longer despite non-surgical treatment;
• Capable of understanding and signing the consent form; and
• Willing and able to comply with follow-up requirements

Exclusion criteria

• A previous interbody fusion at the involved level;
• Greater than grade 2 spondylolisthesis;
• Systemic infection or active infection at the surgical site;
• Active malignancy;
• Body Mass Index of 40 or higher;
• Significant metabolic bone disease (e.g. osteoporosis or osteomalacia) to a degree that spinal instrumentation is contraindicated;
• Taking medications that may interfere with bone or soft tissue healing (e.g. long-term steroid use);
• Alcohol or drug abuse;
• Waddell Signs of Inorganic Behavior >3;
• Currently in litigation regarding a spinal condition;
• Known sensitivity to implant material;
• A prisoner;
• Pregnant or contemplating pregnancy during the 24-month follow-up period; and
• Enrolled in another concurrent clinical trial.