Evaluation Of Spinelink® Fixation In The Treatment Of Degenerative Spondylolisthesis And Spinal Instability

This will be an open, prospective, multi-center outcome study. This study will be conducted
at up to ten centers, each of which will enroll approximately 20 patients. A maximum of 200
patients will be enrolled. This patient sample size will allow statistical comparison to
historical literature and allow an inter-center comparison of outcome. Enrollment into the
study may include all patients who have lumbar spinal fusion performed. All spinal fusion
surgery will be performed using the EBI SpineLink® system.

Inclusion Criteria:

1. The patient has demonstrated Grade I or Grade II degenerative spondylolisthesis
exhibited by maximum slippage on flexion and extension radiographs with symptoms that
include back pain and/or leg pain with spinal fusion indicated, or spinal instability
as evidenced by greater than 3 mm of translational motion or greater than 10 degrees
of angular motion between the involved vertebrae as evidenced by flexion-extension
radiographs.

2. This surgery will be the primary fusion attempt with no more than three (3) vertebrae
or 2 disc spaces involved.

3. The patient must be available for yearly follow-up in the study until completion of
the 24 month evaluation.

4. The patient must be skeletally mature (epiphyses closed).

5. Bone grafting material must be limited to autograft and/or bone-bank allograft.

6. The patient must be willing to comply with the treatment regimen, follow-up
requirements, and have the legal ability to give informed consent.

Exclusion Criteria:

1. Patients with supplemental spinal internal fixation devices previously implanted at
any other level and/or a previous fusion attempt at the involved level(s) (no
interbody fusions, salvage procedures, or prior hardware).

2. Patients with other pathology at the involved spinal level, e.g., osteomyelitis,
Paget's disease, pathologic fracture, etc.

3. Patients with a disease entity or condition that totally precludes the possibility of
bony fusion such as known active cancer, etc.

4. Patients who have significant metabolic diseases including insulin dependent
diabetes, renal dysfunction, etc.

5. Patients involved in personal injury litigation.

6. Pregnant or nursing females.

7. Patient in whom unapproved biologicals (e.g. BMP-2) or bone substitute materials
(e.g. Grafton) would be used at the fusion site.

8. Patients who are unable to understand and sign an informed consent or who, in the
opinion of the investigator, would be psychologically unwilling or unable to
understand or complete the protocol, especially those unwilling or unable to
participate in the follow-up.