BalancedBack Total Joint Replacement Investigational Device Exemption Study


About this study

The purpose of this study is to treat the study population by demonstrating clinical success, safety, and effectiveness of the BalancedBack Total Joint Replacement device, and to demonstrate noninferiority.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Male or female, age 21-80 (inclusive) with at least 3 years of life expectancy.
  • The subject has a primary diagnosis of symptomatic lumbar degeneration with or without foraminal or recess stenosis of the lumbar spine at a single level from L1/L2 to L5/S1 confirmed by subject history and radiographic imaging (CT, MRI, X-rays) with no more than a Grade 1 (< 25% translation) spondylolisthesis. Symptomatic lumbar degeneration that may be associated with a co-morbid condition such as:
    • Herniated nucleus pulposus;
    • Scarring/thickening of the ligamentum flavum, annulus fibrosus, or facet joint capsule;
    • Facet joint degeneration/osteophyte formation;
    • Spondylosis (defined by the presence of osteophytes);
    • Disc degeneration and/or annular degeneration; and/or
    • Lumbar stenosis defined by spinal cord or nerve root compression.
  • Exhausted conservative treatment (e.g. bed rest, physical therapy, medications, TENS, manipulation, and/or spinal injections) for at least 3 months or has a neurologic emergency.
  • Preoperative Oswestry Disability Index score > 40/100 at baseline.
  • Psychosocially, mentally and physically able to fully comply with this protocol including adhering to follow-up schedule and requirements and filling out forms
  • Signed informed consent.

Exclusion Criteria: 

  • More than one vertebral level requiring treatment.
  • Previous instrumented surgery (i.e., anterior disc replacement, spinal fusion, interspinous device, etc.) at the index lumbar level or an adjacent level.
  • Degenerative or lytic spondylolisthesis greater than Grade 1 (< 25% translation).
  • Rotatory scoliosis at the level to be treated.
  • Congenital bony and/or spinal cord abnormalities at the level to be treated.
  • Subcaudal defect, disrupting the integrity of the pedicle.
  • Clinically compromised vertebral bodies at the involved level due to current or past trauma, e.g., by the radiographic appearance of the fracture callus, malunion or nonunion.
  • Disrupted anterior longitudinal ligament at the index level.
  • Overlying thoracolumbar kyphosis (greater than or equal to 15 degrees) within one level (includes target and adjacent level) of the level to be treated.
  • Back pain of unknown etiology without leg pain.
  • Severe spondylosis at the level to be treated as characterized by any of the following:
    • Autofusion (solid arthrodesis) determined radiographically (CT);
    • Totally collapsed disc, or;
    • Vertebral body that cannot be mobilized.
  • Known allergy to cobalt, chromium, molybdenum, nickel, polyethylene, titanium, or vitamin E.
  • Unable to undergo an MRI scan, CT scan or other radiograph assessments.
  • Osteopenia: The SCORE/MORES will be utilized to screen if a DEXA scan is indicated. If SCORE/MORES value ≥ 6, then a DEXA scan is required. If DEXA is required, exclusion will be defined as a DEXA bone density measured T score ≤ -1. An existing DEXA is allowed if completed within 6 months of subject screening.
  • Has history of any endocrine or metabolic disorder known to affect osteogenesis (e.g., Paget's disease, renal osteodystrophy, Ehler-Danlos syndrome, or osteogenesis imperfecta).
  • Insulin-dependent diabetes mellitus.
  • Lactating, pregnant or interested in becoming pregnant in the next 3 years; 18. Active infection – systemic or local.
  • Any medical condition requiring treatment with any drug known to potentially interfere with bone/soft tissue healing or receiving radiation therapy that is expected to continue for the duration of the study.
  • Body Mass Index > 40.
  • Recurrent history of deep vein thrombosis, symptoms of arterial insufficiency, or thromboembolic disease.
  • Systemic disease including Lupus disease, Reiter’s disease, Rheumatoid disease, AIDS, HIV, hepatitis or autoimmune disease that requires immunosuppressive therapy, including biologics, for systemic inflammation.
  • Spinal tumor.
  • Active malignancy: A patient with a history of any invasive malignancy (except non-melanoma skin cancer), unless he/she has been treated with curative intent and there have been no clinical signs or symptoms of the malignancy for at least 5 years.
  • Any degenerative muscular or neurological condition that would interfere with evaluation of outcomes, including but not limited to Parkinson’s disease, amyotrophic lateral sclerosis (ALS), or multiple sclerosis.
  • Has chronic or acute renal and/or hepatic impairment and/or failure or prior history of renal and/or hepatic parenchymal disease.
  • Has a Waddell Signs of Inorganic Behavior score of 3 or greater.
  • In the opinion of the investigator, the subject has a behavioral, cognitive, social or medical problem that may interfere with the assessment of the safety or effectiveness of the device.
  • Current or recent history of chemical/alcohol abuse or dependency using standard medical definition of DSM-5 code.
  • Currently smoking or using tobacco products, including e-cigarette products (e.g., vaping) (Use within 30 days of screening date is considered ‘current’).
  • Currently pursuing or in active spinal litigation for medical negligence, or trauma, or workers compensation.
  • Is a prisoner, incarcerated, or has been coerced to participate in the study that could impact the validity of results.
  • Is currently participating in an investigational therapy (device and/or pharmaceutical) within 30 days prior to entering the study or such treatment is planned during the 24 months following enrollment into the study.

Eligibility last updated 8/1/22. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Ahmad Nassr, M.D.

Open for enrollment

Contact information:

Clay Ward

(507) 293-9972

More information


Publications are currently not available

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