PMCF Study Fortilink-TS Ti

This study is setup to be able to gather information on the safety and performance of the Fortilink-TS Ti cage of Paradigm Spine GmbH, up to one-year after the surgery. The device is intended to be used in intervertebral fusion surgery. Around 50 participants will participate in this study in 2 hospitals. The Fortilink-TS Ti cage is meant to be placed in the lower back, to treat degenerative disc disease with up to grade I spondylolisthesis. The study will involve data gathering based on routine care. The study will only entail collection of data (medical history prior to the surgery, data from the surgery and data in the follow up after one year). Fortilink-TS Ti cages are not new, but have been on the market since 2020. The clinical study is performed to actively gather data on the use of this product in the intended group of patients, to monitor its safety and performance. The treatment and follow-up provided in this study does not differ from the standard of care; meaning that participants in the study will receive the same treatment and follow the same follow-up visits and assessments as patients undergoing the same procedure outside of the study.

Inclusion Criteria: 1. Willing and able to give voluntary informed consent 2. Skeletally mature patients 3. At least 6 months of non-operative treatment 4. Degenerative disc disease (DDD) of the lumbar spine at one or two contiguous levels between L2 and S1, with DDD being defined as back pain of discogenic origin with degeneration of the disc confirmed by history and radiographic studies, and/or up to grade 1 spondylolisthesis of the lumbar spine at one or two contiguous levels between L2 and S1 Exclusion Criteria: 1. Active systematic infection or an active infection at the operative site 2. A demonstrated allergy or sensitivity to any of the implanted materials 3. Severe osteoporosis (confirmed by imaging in the patient's medical history or during screening) 4. Primary or metastatic tumours affecting the spine (confirmed by imaging in the patient's medical history or during screening) 5. Conditions that may place excessive stresses on the bones and the implants, including but not limited to morbid obesity or other degenerative diseases, at the discretion of the investigator 6. Patients whose ability to follow postoperative restrictions, precautions and rehabilitation programs is limited 7. Fractures, severe deformities or a severe instability in the area of surgery (confirmed by imaging in the patient's medical history or during screening) 8. A medical or surgical situation that would preclude the benefit of surgery 9. Pregnancy 10. Patient's denial for operative treatment, post-operative rehabilitation program, follow up appointments and/or participation in the trial 11. Protocol specified surgical technique cannot be followed for the subject 12. Any other reason (in the judgment of the investigator).