Study to Assess the Performance of MagnEtOs Flex Matrix Compared to Cellular Allograft

This is a prospective, randomized, multi-center study that intends to demonstrate the performance of MagnetOs Flex Matrix compared to Cellular Allograft in patients with leg pain and/or back pain requiring up to four-level instrumented PLF surgery.

Inclusion criteria

• Patient is able to read/be read, understand, and provide written informed consent and has signed the IRB approved informed consent.
• Male or female patient ≥ 18 years old.
• Patients with leg pain, and/or back pain requiring up to four-level instrumented posterolateral lumbar/thoraco-lumbar fusion (T11 - S1).
• Failed conservative treatment (physical therapy, bed rest, medications, spinal injections, manipulations, or transcutaneous electrical nerve stimulation) for a minimum period of 3 months prior to study enrollment.

Exclusion criteria

• Requires greater than four-level fusion or expected to need secondary intervention within one year following surgery.
• Had prior PLF fusion or attempted PLF fusion at the involved levels.
• Had previous decompression at the involved levels.
• Women who are or intend to become pregnant within the next 12 months.
• To treat conditions in which general bone grafting is not advisable.
• In conditions where the surgical site may be subjected to excessive impact or stresses, including those beyond the load strength of fixation hardware (e.g., defect site stabilization is not possible).
• In case of significant vascular impairment proximal to the graft site.
• In case of severe metabolic or systemic bone disorders (e.g., osteogenesis imperfecta or Paget's Disease) that affect bone or wound healing.
• In case of acute and chronic infections in the operated area (soft tissue infections; inflammation, bacterial bone diseases; osteomyelitis).
• When intraoperative soft tissue coverage is not planned or possible.
• Undergoing any procedure that allows MagnetOs to come in direct contact with the articular space.
• Receiving treatment with medication interfering with calcium metabolism.
• Has leg pain, and/or back pain related to benign or malignant tumor.
• Has history or presence of active malignancy.
• Has known substance abuse, psychiatric disorder, or a condition which, in the opinion of the investigator, may influence the healing or ability to comply with protocol requirements.
• Is involved in active litigation relating to his/her spinal condition.
• Has participated in an investigational study within 30 days prior to surgery for study devices