The purpose of this study was to compare histologic and MRI evaluation of articular cartilage regeneration in patients with chondral lesions treated by arthroscopic subchondral drilling followed by postoperative intra-articular injections of hyaluronic acid (HA) with and without peripheral blood stem cells (PBSC)

The purpose of this study was to compare histologic and magnetic resonance imaging (MRI) evaluation of articular cartilage regeneration in patients with chondral lesions treated by arthroscopic subchondral drilling followed by postoperative intra-articular injections of hyaluronic acid (HA) with and without peripheral blood stem cells (PBSC)

Inclusion Criteria:

• Patients who have signed informed consent form
• Patients with only unilateral isolated or multiple knee articular cartilage lesions demonstrated MRI scanning, with up to one previous operation on that knee
• Patients who are either male or female aged between 18 to 50 years old, corresponding to availability of normative International Knee Documentation Committee (IKDC) data.
• Female patients of childbearing age must have negative pregnancy tests and are advised to take contraceptive precautions throughout the study.

Exclusion Criteria:

• Patients with bilateral knee lesions
• Patients with the presence of ligamentous injury which would require reconstruction, varus or valgus deformity greater than 10 degrees, previous open total menisectomy requiring osteotomy, and cases that require complex surgery prior to cartilage regeneration
• Patients with significant cognitive impairment, non-ambulatory status or lower extremities amputation other than toes, serious illness or medication affecting operative risk or wound healing (e.g. steroid intake, anticoagulation), and poorly controlled diabetes mellitus with a baseline HbA1c more than 8
• Patients with significant peripheral vascular disease as indicated by absent dorsalis pedis or posterior tibial pulses.
• Patients who cannot read English will be excluded from the study as they will be unable to complete the study questionnaires in an objective manner
• Female patients who are pregnant
• Patients with any contradictions to MRI scanning
• Patients with body mass index (BMI) of over 35