This study aims to evaluate the performance and safety of the Orthoss® as a bone graft extender in lumbar spondylodesis involving 1-2 levels (L4-L5 and/or L5-S1).

This clinical investigation is a prospective, non-interventional, uncontrolled clinical trial, organized to generate clinical data on performance and safety of Orthoss® as a bone graft extender mixed with local bone at ratio of 1:1 and pedicle bone marrow aspirate in lumbar spondylodesis involving 1-2 levels. (Orthoss® is CE marked for this indication).

If you as a patient have a wear and tear disease of the spine, an operation serves to restore the stability of the spinal column. In order to promote a bony build-up of the lumbar spine segment (fusion), bone replacement material is used in your case as standard. The aim of this observational study is to determine fusion in order to address clinical performance of that bone replacement material.

Inclusion Criteria:

• The patient (male or female) must be 18 years or older
• The patient must be a candidate diagnosed with either degenerative disc disease including 1-2 level (L4-L5 and/or L5-S1) or dysplasic spondylolisthesis (degree 1 or 2) or lumbar stenosis
• If the patient is of child-bearing potential, the patient confirms not to be pregnant
• The patient is able to comply with the clinical investigation-related procedures such as attending all follow-up procedures
• The patient is able to fully understand the nature of the proposed surgery and is able to provide a signed informed consent including the use of the anonymized data for scientific publication
• The patient will not participate in another clinical investigation during this clinical investigation

Exclusion Criteria:

• General contraindications for surgical treatment are present
• The patient has a history of malignancy, radiotherapy, or chemotherapy for malignancy within the past five years
• The patient is currently being treated with radiation, chemotherapy, immunosuppression or steroid therapy dose equivalent of more than 5mg prednisolon
• The patient is pregnant or nursing
• Women of childbearing age who are not using a highly effective method of birth control
• The patient has acute or chronic infection at the surgical site
• The patient has a known allergy to bovine bone material
• The patient has a medical history of alcohol or drug abuse within the last year prior to the screening examination
• Vulnerable population
• Patient is currently participating, or has participated in another clinical investigation within 6 months

Orthoss® mixed with local bone and pedicle bone marrow aspirate in lumbar spondylodesis by using transforaminal lumbar interbody fusion (TLIF) and posterior lumbar interbody fusion (PLIF) techniques in the 1-2 levels.