Among various restorative cell-based cartilage treatments, the use of umbilical cord blood-derived mesenchymal stem cell (hUCB-MSC) implantation with concomitant HTO procedure is used to improve clinical and anatomic outcomes in patients with varus malalignment and medial compartment osteoarthritis.
We retrospectively evaluated a total of 146 patients who were performed open wedge HTO procedure and hUCB-MSC implantation from 2013 to 2021. We categorized those with HTO only as group A (23 patients) and those with HTO and hUCB-MSC implantation as group B (40 patients). At 12th month postoperatively, the cartilage regeneration was assessed macroscopically based on ICRS grading system and Oswestry Arthroscopy Score (OAS); in addition, the location, size, and histological assessment of cartilage lesions were further evaluated. International Knee Documentation Committee (IKDC), Knee Injury and Osteoarthritis Outcomes Scores (KOOS), and VAS scores were evaluated for secondary clinical outcome measures at preoperatively and last follow-up.
At median follow-up periods of 2.3 years, clinical scores (IKDC, KOOS, and VAS scores), all improved from preoperative to the last follow-up in both groups with statistical significance. Both groups showed improved postoperative lower extremity alignment, indicating hip-knee-ankle angle from 7.19 to 2.1 in Group A and from 8.25 to 2.54 in Group B. However, Group B showed better macroscopic appearances and characteristics in chondral regeneration (26.3% of patients improved to ICRS Gr I, 53.1% to ICRS Gr II, 3.3% to ICRS Gr III) than Group A (12.6% of patients improved to ICRS Gr I, 27.5% to ICRS Gr II, 33% to ICRS Gr III). In addition, macroscopic evaluation of cartilage repair based on OAS scoring also indicated similar results (mean 7.52 points in group A and mean 3.56 points in Group B).
hUCB-MSC implantation with concomitant HTO procedure for medial compartment osteoarthritis was safe and indicated better signs of cartilage repair status compared to HTO alone.