Implantation of allogenic umbilical cord blood-derived mesenchymal stem cells improves knee osteoarthritis outcomes: Two-year follow-up

Abstract

Introduction: Clinical outcomes after the implantation of allogenic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in osteoarthritic knees have been rarely reported. Our study aimed to investigate clinical outcomes of osteoarthritic patients who underwent hUCB-MSC implantation.

Methods: In this case series (level of evidence: 4), from January 2014 to December 2015, 128 patients with full-thickness cartilage lesions (International Cartilage Repair Society grade 4 and Kellgren-Lawrence grade ≤3) who underwent hUCB-MSC implantation were retrospectively evaluated with a minimum of 2-year follow-up. After removing the sclerotic subchondral bone with an arthroscopic burr, 4-mm-diameter holes were created at 2-mm intervals, and hyaluronic acid and hUCB-MSCs were subsequently mixed and implanted in the holes and other articular defect sites.Clinical outcomes were evaluated preoperatively, 1 year postoperatively, and 2 years postoperatively (minimum) using visual analog scale (VAS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and International Knee Documentation Committee (IKDC) scores. To assess clinical outcomes, patients were divided into two or three groups according to the lesion size, lesion location, number of lesions, body mass index, and age; statistical analyses were performed using these data.

Results: The mean (±standard deviation) VAS, WOMAC, and IKDC scores at 1 and 2 years after surgery including hUCB-MSC implantation improved significantly compared to the preoperative scores (P < 0.001). There were significant differences in the lesion location (P < 0.05). Medial femoral condyle lesions resulted in worse outcomes compared with lateral femoral condyle and trochlea lesions. No adverse reactions or postoperative complications were noted.

Conclusions: Implantation of hUCB-MSCs is effective for treating knee osteoarthritis based on a follow-up lasting a minimum of 2 years.

Keywords: ACI, autologous chondrocyte implantation; AT-MSCs, adipose tissue-derived MSCs; Allogenic; BM-MSCs, bone marrow-derived MSCs; BMI, body mass index; HA, hyaluronic acid; Human umbilical cord blood; IKDC, International Knee Documentation Committee; KL, Kellgren–Lawrence; Knee osteoarthritis; LFC, lateral femoral condyle; MFC, medial femoral condyle; MRI, magnetic resonance imaging; Mesenchymal stem cells; OA, osteoarthritis; OAT, osteochondral autologous transplantation; VAS, visual analog scale; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index; hUCB-MSCs, human umbilical cord blood-derived mesenchymal stem cells.

Fig. 1

(a) A 58-year-old woman had a lesion on the medial femoral condyle and a focal lesion on the medial tibial plateau of the left knee. (b) The damaged cartilage was completely removed, and the sclerotic subchondral bone was removed. Multiple holes with a diameter of 4 mm and 2 mm were created on the medial femoral condyle. (c) After a mixture of hyaluronic acid and human umbilical cord blood-derived mesenchymal stem cells was implanted in the holes and trimmed to the height of surrounding articular surface on the medial femoral condyle. (d) Second-look arthroscopy at 15 months after surgery. This was performed during opposite knee surgery.

Fig. 2

(a) Short tau inversion recovery MRI of a 55-year-old female patient showing International Cartilage Repair Society grade IV defect (arrow) on the medial femoral condyle (b), which is completely filled with repair tissue (arrow) at 13 months after surgery.