ACADIA (TM) Facet Replacement System

Principal Investigator: Darrel Brodke
Keywords: ACADIA , Facet Replacement System , Lateral Recess , Central Canal Stenosis Department: Orthopedic Surgery
IRB Number: 00060112 Co Investigator: Brandon  Lawrence
Specialty: Orthopaedic Surgery, Orthopaedic Surgery
Sub Specialties: Spine Surgery
Recruitment Status: Active, not recruiting

Contact Information

Ashley Woodbury

Brief Summary

The purpose of this study is to evaluate the safety and effectiveness of the AFRS in patients with lateral, lateral recess and/or central canal stenosis due to facet degeneration at a single level from L3 to S1 who require a lumbar decompression and facetectomy compared to an instrumented posterolateral fusion control group.  Safety of the AFRS device will be evaluated by the incidence, severity and device or procedure relatedness of all adverse events over the 24 month assessment period as compared to the control group.  Effectiveness of the AFRS will be based on the improvement in symptom-related questionnaire scores, funcion, and neurological status.

Inclusion Criteria

21-85 years of age and skeletally mature;

Undergone at least six cumulative months of conservative treatment prior to

surgery including any of the following: medications, NSAIDs, physical therapy,

bracing, chiropractic manipulation, modified activities of daily living, epidural

injections, facet block injections;

Lateral, lateral recess and/or central canal stenosis as demonstrated by

compression of the thecal sac and/or cauda equina, nerve root impingement by

either osseous or non-osseous elements or evidence of hypertrophic facets with

encroachment into the central canal or lateral recess at the involved level as

determined by MRI, CT scan, plain film or myelography;

Disc height measuring 4 mm at the operative level;

Persistent leg, thigh and/or buttock symptoms, including pain, numbness, burning

or tingling with a minimum leg pain score of 40mm as measured with the VAS;

Score greater than 2 on a scale of 1-5 on the ZCQ Symptom Severity Score

Score greater than or equal to 2 on a scale of 1-4 on the ZCQ Physical Function


Candidate for a decompression with full facetectomy at the operative level;

Candidate for an instrumented posterolateral fusion;

Willing and able to comply with postoperative and routinely scheduled clinical

and radiographic evaluations;

Lives in the immediate area and has no plans to relocate to another geographic

area before the completion of the study, or lives outside the immediate area and is

willing to comply with scheduled postoperative visits with a designated


Has signed a patient informed consent, specific to this study.

Exclusion Criteria

Previous surgical procedure at the operative or adjacent level except for one of

the following: micro-discectomy, laminectomy, lamino/foraminotomy, rhizotomy,

IDET, and/or interspinous spacer;

Previous lumbar fusion or disc replacement procedure;

Osteoporosis as defined by Simple Calculated Osteoporosis Risk Estimation

(SCORE) screening questionnaire score of 6 or greater and DEXA bone density

measured T-score –2.0;

Greater than Grade I spondylolisthesis or retrolithesis, as defined by the

Meyerding Grading Classification, at the operative level;

Spondylolisthesis any grade, as defined by the Meyerding Grading Classification

at levels other than at the operative level;

Scoliosis of the lumbar spine (defined as more than 11° Cobb angle), as indicated

by plain X-ray films;

Primary diagnosis of discogenic back pain due to torn, herniated, inflamed or

irritated disc or other pathology where the patient exhibits axial back pain from

degenerative disc disease;

Acute traumatic pars fracture at the operative or adjacent level vertebral body;

Spinal stenosis at more than three lumbar segments;

Experienced acute trauma to the lumbar spine within the last 24 months;

Active infection at the operative level, or a systemic infection including prior or

pending treatment for HIV or Hepatitis C;

Physically or mentally compromised (i.e., being currently treated for a psychiatric

disorder, senile dementia, Alzheimer's disease, presence of alcohol or substance

abuse) in a manner that would compromise his or her ability to participate in the

clinical study;

Diagnosed systemic disease (i.e., Paget's disease, muscular sclerosis, amyotrophic

lateral sclerosis (ALS),renal osteodystrophy, metastasis to vertebrae, Lupus, or

ankylosing spondylosis) that may affect the patient’s welfare or overall outcome

of the research study;

Immunologically suppressed or immunocompromised;

Insulin-dependent diabetes mellitus (type I diabetes);

Currently undergoing long-term steroid therapy (treated in the last 6 months with

systemic corticosteroids);

Metabolic bone disease (i.e., osteomalacia, and/or osteogenesis imperfecta);

Is of child-bearing potential, and is either pregnant or interested in becoming

pregnant during the duration of the study;

Medically significant obesity as defined by a Body Mass Index (BMI) of > 40

kg/m2. BMI = (weight in pounds × 703) ÷ (height in inches × height in inches);

Active malignancy: a history of any invasive malignancy (except non-melanoma

skin cancer), unless the patient has been treated with curative intent and there

have been no clinical signs or symptoms of the malignancy for at least 5 years;

Known allergy to cobalt chromium or titanium;

Used any investigational drug or device within the past 30 days;

Pending litigation related to back pain or injury;

Is a prisoner.