Donor stem cells injected into knees: safe or not?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Willing and able to provide written informed consent and comply with all procedures required by the protocol 2. Aged \> 18 years at the time of signing the informed consent form 3. Diagnosed with knee OA according to American College and Rheumatology criteria and showing a stage of a mild to moderate arthritis. 4. Kellgren-Lawrence radiological classification scale II and III at screening 5. Visual analogue scale (VAS) joint pain ≥ 2.5 at screening 6. Have tried but failed conservative management including physical therapy, bracing and medications for a minimum of three months. 7. No history of prior intra-articular cortisone, hyaluronic acid, or platelet-rich plasma injection within the previous six months 8. No history of prior arthroscopic knee surgery or open knee surgery on the ipsilateral side within the past year 9. Adequate liver and renal functions with non-malignant blood profile. 10. Body Mass Index between 20 and 30 kg/m2 11. Negative for (HIV, HTLV1\&2, Hep A, B, C, syphilis) infection as determined by approved serological testing 12. Negative for pregnancy as determined by a serum pregnancy test. Females of childbearing potential will be required to practice abstinence or use an effective form of contraception for 12 months following their MSC injection. 13. Fluid \> 1 cm within the lateral recess of the suprapatellar pouch at the level of the superior pole of the patella with the knee extended. Exclusion Criteria: 1. Unwilling or unable to perform any of the assessments required by the protocol 2. Patients with clinically unstable knee due to the presence of a complete anterior cruciate ligament, posterior cruciate ligament, medial collateral ligament and/or posterolateral corner tear 3. Patients with varus or valgus malalignment \>5 degrees as measured by 4-foot standing antero-posterior radiographs 4. Patients with a history of a previous subtotal medial or lateral meniscectomy 5. Patients with a history of septic arthritis in the affected joint 6. Patients with a history of a prior intra-articular knee fracture 7. Severe bleeding diathesis 8. Active infection 9. Patients with unforeseen conditions that are deemed unsafe or inappropriate for the study (e.g., patients who are claustrophobic and cannot undergo an MRI) as per the discretion of the principal investigator 10. Patients with neoplasia 11. Patients participating in another clinical trial or treatment with a different investigational product within 30 days prior to inclusion in this study 12. Patients with a known history of inflammatory or rheumatic diseases such as rheumatoid arthritis