CONDUIT™ Anterior Lumbar Interbody Fusion (ALIF) Cage System in Lumbar Degenerative Disease

This will be a prospective, multi-centre study at a National Tertiary Referral Centre for spinal trauma and spinal cord injuries, serving a catchment area of 5 million people. This study will follow patients undergoing anterior lumbar interbody fusion (ALIF) procedure at the Mater Misericordiae University and Mater Private Hospitals using the CONDUIT™ ALIF Cage System. This trial seeks to evaluate the performance of this CE-marked device, and to assess outcomes in frail and non-frail patient cohorts. The CONDUIT™ ALIF Cage System are intervertebral body fusion devices intended for use for anterior lumbar interbody fusion in skeletally mature patients. The devices are 3D printed cellular titanium implants that feature 80% porous macro-, micro- and nanostructures, are designed to mimic cortical and cancellous bone, and facilitate fusion.

In spine fusion procedures, bone is encouraged to grow in order to fuse vertebrae of the spine together to relieve pain or increase stability. The likelihood of a successful fusion is thought to be influenced by multiple factors. Patient-related factors influencing fusion success include comorbidities such as osteoporosis or osteopenia, diabetes, and obesity. Factors affecting the inflammatory response, such as rheumatoid arthritis or long-term steroid use may also increase the likelihood of fusion failure. Fusion success can also be influenced by age, frailty, functional status, history of smoking or steroid use. The surgical approach may also affect fusion rate. It is thought that a posterior approach may result in higher fusion failure rates (20-30%. However, the posterior approach may be considered more appropriate for older patients with multilevel fusion, who may have a higher rate of comorbidities which affect fusion rate.

Frailty is a clinically recognizable syndrome comprised of declining physiological reserve, characterized by decreased resilience to adverse health outcomes. Fried et al have defined frailty as meeting three out of five of the following criteria: low grip strength, low energy, slow walking speed, low physical activity, unintentional weight loss. The modified 5-item frailty index (mFI-5) is another method of measuring frailty commonly used in clinical settings. It has been shown to predict the occurrence of adverse outcomes following various orthopaedic surgeries. The five comorbidities included in the mFI-5 are a history of hypertension, COPD, diabetes mellitus, congestive heart failure, and a non-independent functional status. This pilot study hypothesizes that the use of CONDUIT ALIF Cage system to treat lumbar degenerative disc disease will achieve results comparable to historical cases using SYNFIX Systems.

Inclusion criteria

• Aged ≥ 18 years old
• Consenting patients undergoing anterior lumbar interbody fusion (ALIF) procedure whom the Conduit cage system is appropriate will be included in this study.

Exclusion criteria

• Patients under 18 years of age
• Non-surgical candidates, patients with contraindications to surgery (e.g. medical comorbidities, known infection, pregnancy etc.),
• Patients with established osteoporosis
• Long-term, systemic steroid use
• Systemic diseases (e.g. rheumatoid arthritis, AIDS, HIV, etc.),
• Patients unwilling or unable to give informed consent, or patients unwilling or unable to complete Health-related quality of (HRQOL) outcome life measures at the specified study time points pre- and post-operatively.
• Subjects who have a history of drug or alcohol use that, in the opinion of the investigator, would interfere with adherence to study requirements.