This is a pilot study to assess safety and possible efficacy of Allocetra-OTS in end-stage knee osteoarthritis.

Inclusion Criteria:

1. Age 18 or older.
2. Diagnosed with end-stage knee osteoarthritis and are scheduled or offered surgery.
3. X-ray positive for knee osteoarthritis.
4. Pain and functional disability from osteoarthritis.
5. Acceptable blood workup results (CBC, electrolytes, kidney and liver function) from up to three months before treatment.
6. Mentally and physically able to fully comply with the study protocol.
7. Signed Informed Consent form.

Exclusion Criteria:

1. Evidence of active local infection in the vicinity of the knee joint.
2. Previous surgery of total or partial knee replacement in the injected knee.
3. Patients unable to provide informed consent due to language barrier or mental status.
4. Patients with a major medical condition that would affect quality of life and influence the results of the study.
5. Patients unwilling to be followed for the duration of the study.
6. Acute infection requiring intravenous antibiotics at the time of screening.
7. Other limb pain of unknown etiology.
8. Pain in the limb clinically assessed to arise from an origin which is not the affected knee joint.
9. Known neurological disease or rheumatic condition other than osteoarthritis.
10. Bleeding disorders.
11. Known cognitive disorder.
12. Concurrent participation in any other clinical study. Participation in an interventional investigational study within 30 days prior to enrollment.
13. Physician objection.
14. Positive pregnancy test.