**Study Overview:** This study looks at using a special carbon fiber device called the Carbofix Pedicle Screw System to help people with back problems. The study will compare this carbon device to traditional titanium devices often used in spine surgeries. The carbon device is special because it doesn't interfere with X-rays or other scans like MRIs, making it easier for doctors to see inside the body during and after surgery. The study aims to help people with conditions like degenerative spinal diseases, which affect the spine's structure and can cause pain or discomfort. **3 Key Points:** - **Participation:** 118 patients are needed. Participants should be adults (18+ years) requiring lumbar fusion surgery. - **Involvement:** Participants will need to agree to follow-ups and sign a consent form. - **Exclusions:** People with certain health conditions, like bone diseases or mental health disorders, cannot participate. By joining, you can help doctors learn more about how these new carbon devices work compared to the usual titanium ones.