Safety and Efficacy Assessment of Using the zLOCK Facet Stabilization System

Inclusion Criteria:

1. Patient is scheduled for spine surgery with at least one of the following:

• Degenerative Spondylolisthesis grade 1;
• Mild to Moderate stenosis;
• Degeneration of the facets.

2. When used stand-alone disc height should be maximum 50% of the adjacent disc height.
3. 18< Age <75
4. Weight < 100Kg
5. Signed informed consent form
6. At least 3 months of unsuccessful conventional treatments

Exclusion Criteria:

1. Fusion procedure performed or required in more than one motion segment.
2. Acute or chronic spinal infections.
3. Osteoporosis when used in adjunct to an anterior interbody cage (DEXA < -2.5).
4. Absence of posterior spinal elements including the pedicle, pars interarticularis,facet joints, spinous process and the majority of the lamina which make it unstable ornot possible to place.
5. Any entity or conditions that totally preclude the possibility of fusion, i.e. canceror kidney dialysis.
6. Obesity (BMI ≥30)
7. Unilateral application of device, except in combination with anterior interbody cages.
8. Known sensitivity to Titanium.
9. Alcoholism, or drug abuse
10. Subject with a cardiac pacemaker or other implanted electro medical device
11. Women who are either pregnant or nursing at the time of screening (to be verified bytest in case of woman of child-bearing potential that do not practice medicallyacceptable methods of contraception)
12. Concurrent participation in another clinical trial using any investigational drug ordevice.
13. Mental disorders.
14. Tumor
15. Fracture or other instabilities of the posterior elements.