Published online Jun 26, 2020. doi: 10.4252/wjsc.v12.i6.514
Peer-review started: February 21, 2020
First decision: March 30, 2020
Revised: April 24, 2020
Accepted: May 12, 2020
Article in press: May 12, 2020
Published online: June 26, 2020
High tibial osteotomy (HTO) is widely used to treat medial compartment osteoarthritis (MCOA) of the knee with varus deformity. HTO reduces knee pain and improves knee function by decreasing the pressure in the medial compartment of the knee.
HTO alone offers excellent short- and mid-term outcomes; however, these outcomes tend to deteriorate over time. For further improvement in knee joint condition, cartilage regeneration can be combined with HTO. Autologous chondrocyte implantation (ACI), osteochondral autologous transplantation (OAT), and microfracture have been known to be effective therapies for articular cartilage regeneration, but they are not suitable in case of osteoarthritis (OA) therapy. Recently, mesenchymal stem cells (MSCs) have been identified as a new option in the field of cartilage regeneration for the treatment of OA patients. The MSCs isolated from human umbilical cord blood (hUCB-MSCs) demonstrate higher proliferation and chondrogenic capacity than other MSCs. Reports on the clinical application of hUCB-MSCs are scarce, and there are no studies examining the use of hUCB-MSCs with concomitant HTO.
This study aimed to evaluate clinical outcomes and cartilage regeneration via second-look arthroscopy after implantation of hUCB-MSCs with concomitant HTO, for treatment of osteoarthritic knee with varus deformity.
A total of 125 patients were included in this study with an average age of 58.3 ± 6.8 years (range: 43-74 years). All the patients had a varus deformity of more than 5° and a full-thickness International Cartilage Repair Society (ICRS) grade IV articular-cartilage lesion of more than 4 cm2 in the medial compartment of the knee. All patients underwent second-look arthroscopy during hardware removal. Cartilage regeneration was evaluated macroscopically using the ICRS grading system in second-look arthroscopy. We also assessed the effects of patient characteristics, such as trochlear lesions, patient age, and lesion size, using the patients’ medical records.
The results obtained in this study show that cartilage was regenerated to ICRS grade III or better in all the cases after implantation of hUCB-MSCs with concomitant HTO. Regenerated cartilage in the ICRS grades I, II, and III groups improved the clinical outcomes of these patients. The ICRS grade I group showed the best clinical outcomes among the three groups. Indeed, all the scores in the ICRS grade I group improved over time compared with those of the ICRS grade II and III groups. Although some patients presented with partially regenerated cartilage, none of the patients showed lack of cartilage regeneration (ICRS grade IV).
Our results show that implantation of hUCB-MSCs with concomitant HTO is an effective treatment option for patients with medial compartment osteoarthritis (MCOA). In addition, our results also suggest that the presence of trochlear or large cartilage lesions, or advanced age of the patient, does not significantly affect clinical outcomes in patients with MCOA undergoing HTO with hUCB-MSC implantation.