Confirmatory Investigation to Evaluate the Performance and Safety of ReSpace TiCell Cage Implants in TLIF

Degenerative disc and facet joint disease of the lumbar spine is common in the ageing population and is one of the most frequent causes of disability. Lumbar spondylosis may result in mechanical back pain, radicular and claudicant symptoms, reduced mobility and poor quality of life. Surgical interbody fusion of degenerative levels is an effective treatment option to stabilize the painful motion segment, and may provide indirect decompression of the neural elements, restore lordosis and correct deformity. Lumbar interbody fusion (LIF) involves placement of an implant (cage, spacer or structural graft) within the intervertebral space after discectomy and endplate preparation. At this time LIF is performed using five main approaches; posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), oblique lumbar interbody fusion/anterior to psoas (OLIF/ATP), anterior lumbar interbody fusion (ALIF) and lateral lumbar interbody fusion (LLIF). There is no clear definitive evidence for one approach being superior to another in terms of fusion or clinical outcomes. These operations can also be performed using mini-open or minimally invasive (MIS) approaches, however it has not yet been demonstrated that MIS-TLIF is clinically superior to traditional open TLIF procedure. Interbody fusion is preferable to postero-lateral 'onlay' fusion techniques due to lower rates of postoperative complications and pseudoarthrosis.

Posterior interbody fusion (PLIF), combined with segmental instrumentation, has become increasingly popular since it was first described by Mercer in 1936 and expanded upon by Cloward. More recently however, the transforaminal approach to the intervertebral disc, known as transforaminal lumbar interbody fusion (TLIF), has gained popularity. Originally described by Harms in the late 1990s, the TLIF has arguably developed into the most commonly performed and efficacious posterior interbody fusion method in modern spine surgery.

Transforaminal lumbar interbody fusion (TLIF) utilizes a more lateral window in order to access the interbody space without excessive dural retraction. Theoretical advantages of TLIF include increased fusion success, more complete foraminal decompression, better correction of deformity, and more effective treatment of discogenic pain.

Transforaminal lumbar interbody fusion (TLIF) have demonstrated excellent fusion rates with acceptable complication profiles for treating single and multilevel lumbar disc pathology and instability. TLIF have been shown to be superior to posterolateral fusion alone for deformity correction and more cost effective than anterior interbody combined with posterior segmental instrumentation.

Inclusion criteria

Each subject must meet all the following criteria to be enrolled in this study:

All subjects who had previously indicated for TLIF surgery can participate in this study, with the following evidence:

• Has degenerative disease of the lumbosacral spine in one or two adjacent levels (L1 to S1), manifested by:

• Low back pain, or
• Irradiating leg or buttock pain, paresthesia, numbness, or weakness, or
• History of neurogenic claudication.
• Has radiographic evidence (e.g. CT, MRI, x-ray, etc.) of degenerative lumbosacral disease including at least one of the following:

• Instability as defined by ≥3 mm translation or ≥5-degree angulation
• Decreased disc height, on average by ≥2 mm, but dependent upon the spinal level
• Scarring/thickening of ligamentum flavum or annulus fibrosis
• Herniated nucleus pulposus
• Vacuum phenomenon
• Grade 1 spondylolisthesis/retrolisthesis based on the Meyerding classification (Meyerding, Henry William, 1932), or lateral listhesis demonstrated by coronal plane translation (slippage) of the superior (cranial) vertebral body lateral to the inferior (caudal) vertebral body less than or equal to 3mm, or
• Stenosis, or narrowing, of the lumbar spinal canal and/or intervertebral foramen requiring significant decompression leading to segmental instability, or
• Recurrent disc herniation

Further inclusion criteria:

• Skeletally mature adults ages 18 - 80 years of age
• Able to read and understand all documents used in this study, including the informed consent and patient-reported outcome questionnaires

Exclusion criteria

Subjects meeting any of the following criteria will be excluded from the study:

• Prior surgical procedure at the involved or adjacent spinal levels (e.g. stabilization, fusion, arthroplasty and/or other non-fusion procedures). Prior microdiscectomy, discectomy, laminectomy, decompression surgery at the target or adjacent levels is allowed.
• Significant lumbar instability defined as sagittal listhesis greater than Grade 2 at any involved level using the Meyerding Classification or lateral listhesis greater than 3 mm at any involved level.
• Planned use of an internal or external bone growth stimulator.
• Lumbar scoliosis >30 degrees.
• Patients who had a previous diagnosis of osteoporosis with a Tscore of -2.5 or below in the last 12 months. If subject has a prevalent fragility fracture and a T-score hasn't been assessed in the last 12 months, a DEXA (dual x-ray absorptiometry) scan will need to be obtained.
• Morbidly obese, as defined by a Body Mass Index (BMI) >40.
• Presence of active malignancy or prior history of malignancy (noninvasive basal cell carcinoma of the skin and non-invasive squamous cell carcinoma localized only to the skin is allowed).
• Overt or active bacterial infection, either local to surgical space or systemic.
• Has undergone administration of any type of corticosteroid, antineoplastic, immunostimulant, or immunosuppressive agents, or medications known to inhibit with the healing of bone or soft tissue within 30 days prior to implantation of the assigned treatment

• This includes patients ≥ 65 years of age taking warfarin with documented diagnosed osteoporosis. All other patients taking warfarin should washout for at least 5 days prior to treatment
• Use of steroidal inhalers, short-term NSAID use, and shortterm steroidal use (e.g. Medrol Dosepak) is allowed pre and postoperatively. For this clinical study, short-term use is defined as ≤ two weeks.
• Use of NSAIDs and/or steroids for longer than two weeks postoperatively through the 24 Month Follow-Up Visit is not recommended. Such patients must be excluded from data analysis in case of non-fusion.
• Co-morbidities, which in the investigator's opinion, precludes the subject from being a surgical candidate.
• Autoimmune disease, which in the investigator's opinion, is known to affect bone metabolism or the spine (e.g., spondyloarthropathies, juvenile arthritis, rheumatoid arthritis, Graves' disease, Hashimoto's thyroiditis).
• Any endocrine or metabolic disorder, which in the investigator's opinion, is known to affect osteogenesis (e.g., Paget's disease, renal osteodystrophy, Ehlers-Danlos syndrome, or osteogenesis imperfecta).
• Known hypersensitivity or allergy to any components of the study treatments including, but not limited to bone morphogenetic proteins (BMPs); injectable collagen; protein pharmaceuticals (e.g.: monoclonal antibodies or gamma globulins); bovine collagen products; and/or instrumentation materials (e.g., titanium, titanium alloy, cobalt chrome, cobalt chrome alloy, or PEEK).
• History of any allergy resulting in anaphylaxis.
• Is mentally incompetent. If questionable, obtain psychiatric consult.
• Treatment with an investigational therapy (drug, device, and/or biologic) targeting spinal conditions within 3 months prior to implantation surgery, treatment with any other investigational therapies within 30 days prior to implantation surgery, or such treatment is planned during the 24-month period following implantation of the study treatment.
• Pregnancy and breastfeeding.
• A documented diagnosis of substance use disorder (Nicotine use is allowed.)
• Any condition, which in the investigator's opinion, would interfere with the subject's ability to comply with study instructions, which might confound data interpretation.
• Subject is considered to belong to a vulnerable population.