Human umbilical cord-blood-derived mesenchymal stem cell can improve the clinical outcome after high tibial osteotomy: study

High tibial osteotomy (HTO) is a well-established surgery for patients with medial osteoarthritis (OA) with varus alignment. Furthermore, a combined cartilage regeneration procedure such as microfracture (MFx) has better survival rate in the long-term. Failed cartilage regeneration is closely related to the early failure of HTO and the need for total replacement arthroplasty.

There is limited study about the human umbilical cord-blood derived mesenchymal stem cell (hUCB-MSC) cartilage regeneration procedures combined with high tibial osteotomy (HTO). Dong Won Suh et al compared the clinical and radiological results of hUCB-MSC cartilage regeneration procedures combined with HTO to those of microfracture with HTO.

The article has been published in “The Knee” journal.

HTO patients with International Cartilage Regeneration and Joint Preservation Society (ICRS) grade IV cartilage defects over 200 mm2 on medial femoral condyle (MFC) were enrolled. For comparison, all participants were divided into two groups: those who had undergone hUCB-MSC induced cartilage regeneration procedure (group MSC) and those with microfractures only (group C, controls).

Arthroscopic examination was performed, including synovectomy, debridement, partial meniscectomy, and/or meniscal repair. For MFC cartilage defects, radical debridement for degenerated or flap fragment of the cartilage was performed to make healthy rim and expose subchondral bone. Then, an anteromedial portal was extended about 2 cm. Using a 4 mm-diameter reamer, multiple 4 mm-deep holes were made in subchondral bone in cartilage defects. After saline drainage, off-the-shelf hUCB-MSC product, Cartistem (MEDIPOST, Seongnam, South Korea), was applied. This product consists of 1.5 mL hUCB-MSCs (7.5 *106 cells/vial) and 4% hyaluronic acid hydrogel, After arthroscopic examination and hUCB-MSC implantation, medial opening-wedge HTO was performed conventionally using an anatomical locking plate with metal wedge

Postoperative rehabilitation protocol, early weight-bearing, was the same in both groups. Clinically, Hospital for Special Surgery (HSS), International Knee Documentation Committee (IKDC), and Lysholm scores were evaluated post-operatively at 18 months. Radiologically, mechanical axis (MA) and joint space width (JSW) were evaluated.

Key findings of the study were:

• A total of 100 knees were enrolled (43 in group MSC, 57 in group C).

• Intra-operatively, mean cartilage defects were 442 ± 210 mm2 in the MSC group and 401 ± 162 mm2 in group C, and there was no significant difference between the two groups.

• Mean sizes of the wedge were 10.0 ± 2.0 mm and 10.3 ± 1.9 mm in the MSC group and group C, respectively, and there was also no significant difference between the two groups.

• The IKDC score in group MSC (69) was better than that in group C (62; P < 0.05).

• The JSW increment in the MSC group (0.6 mm) was more than that in group C (0.1 mm; P < 0.05).

• No patient developed nonunion, correction loss, or arthroplasty conversion.

The authors concluded that – “hUCB-MSCs can improve clinical outcome and JSW better than microfracture only in HTO patients. However, further investigation is warranted for utilizing hUCB-MSC in HTO.”

Further reading:

Human umbilical cord-blood-derived mesenchymal stem cell can improve the clinical outcome and Joint space width after high tibial osteotomy

Dong Won Suh, Seung Beom Han et al

The Knee 33 (2021) 31–37

https://doi.org/10.1016/j.knee.2021.08.028