To observe the short-term efficacy of intra-articular injection of platelet-rich plasma(PRP) and umbilical cord mesenchymal stem cells(MSCs) in the treatment of mild to moderate knee osteoarthritis.

A total of 200 cases of osteoarthritis of knee joint in Liaocheng People′s Hospital were collected. Inclusion creteria: Kellgren- Lawrence grade Ⅰ to Ⅲ patients with osteoarthritis of knee joint. Exclusion criteria: Kelgren-Lawrence grade Ⅳ osteoarthritis patients and inflammatory arthritis patients. According to the pseudo-random numbers generated by the computer, the patients with knee osteoarthritis were randomly divided into PRP+ MSC group, PRP group, MSC group and sodium hyaluronate (SH) group, 50 cases in each group. In PRP+ MSC group, 5 ml PRP and umbilical cord MSCs mixture were injected into articular cavity; in PRP group, 5 ml PRP was injected into articular cavity; in MSC group, 5 ml umbilical cord MSCs were injected into articular cavity; in SH group, 2.5 ml SH and triamcinolone acetonide injection were injected into articular cavity. After one, three, six and 12 months of treatment, the improvement of knee joint function was evaluated by visual analogue scale (VAS) and American Knee Association score (AKS); the changes of cytokines in joint fluid were detected by enzyme-linked immunosorbent assay (ELISA), and the Changes in articular cartilage before and after were evaluated by T2 Map sequence of MRI. Measurement data such as age, course, VAS score, AKS score, and cytokine content were analyzed by one-way ANOVA. Enumeration data such as sex ratio and disease degree of patients were analyzed by chi-square test.

Among the 200 patients, 175 were followed up, 45 in PRP+ MSC group, 44 in PRP group, 43 in MSC group and 43 in SH group. There was no significant difference in the expression of cytokines in VAS, AKS and synovial fluid between the four groups before treatment (P >0.05). One month after treatment, the VAS scores of the four groups were lower than before, and the AKS scores were higher than before. There was significant difference between the groups (t=6.45, P <0.01), and there was no significant difference between the groups (P >0.05). Three months later, VAS and AKS in SH group tended to be in the pre-treatment state, while no rebound was found in the other three groups. PRP+ MSC combined injection group was superior to PRP alone and MSC treatment groups. The difference between the four groups was statistically significant (F=7.84, 4.35; P <0.01). Three weeks after treatment, there was no significant change of cytokines in the joint fluid of SH group. The level of cytokines in the joint fluid of PRP+ MSC group was higher than that of PRP and MSC group (F=39.21, P <0.01). Six months after treatment, the average cartilage T2 values of PRP+ MSC group, PRP group, MSC group and SH group were (54.1±2.6)ms, (56.6±1.4)ms, (56.4±1.6)ms, (58.0±2.0)ms, respectively (F=30.63; P <0.05).

Intra-articular injection of platelet-rich plasma and umbilical cord mesenchymal stem cells can significantly improve the symptoms of patients with knee osteoarthritis and delay the progress of osteoarthritis.