Objective To explore the effectiveness and mechanism of pure platelet-rich plasma (P-PRP) on osteochondral injury of talus. Methods Thirty-six patients with osteochondral injury of talus selected between January 2014 and October 2017 according to criteria were randomly divided into control group (group A), leukocyte PRP (L-PRP) group (group B), and P-PRP group (group C), with 12 cases in each group. There was no significant difference in gender, age, disease duration, and Hepple classification among the three groups (P>0.05). Patients in the groups B and C were injected with 2.5 mL L-PRP or P-PRP at the bone graft site, respectively. Patients in the group A were not injected with any drugs. The American Orthopaedic Foot and Ankle Society (AOFAS) score and visual analogue scale (VAS) score were used to evaluate the effectiveness before operation and at 3, 6, and 12 months after operation. Study on the therapeutic mechanism of P-PRP: MC3T3-E1 cells were randomly divided into control group (group A), L-PRP group (group B), and P-PRP group (group C). Groups B and C were cultured with culture medium containing 5% L-PRP or P-PRP respectively. Group A was cultured with PBS of the same content. MTT assay was used to detect cell proliferation; ELISA was used to detect the content of matrix metalloprotein 9 (MMP-9) protein in supernatant; alkaline phosphatase (ALP) activity was measured; and real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the expression of osteopontin (OPN), collagen type Ⅰ, and MMP-9 in cells. Western blot was used to detect the expression of MMP-9 in supernatant and phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (pAKT), and phosphorylated c-Jun (p-c-Jun) in cells. ResultsAll patients were followed up 13-25 months, with an average of 18 months. No complication such as wound infection and internal fixation failure occurred. MRI showed that the degree of injury was similar between the three groups before operation, and patients in the three groups all recovered at 6 months after operation. Moreover, group C was superior to groups A and B. Compared with preoperation, AOFAS scores and VAS scores in the three groups were all significantly improved at each time point after operation (P<0.05). AOFAS score of group C was significantly higher than that of groups A and B at 3, 6, and 12 months after operation (P<0.05); there was no significant difference in VAS score between the three groups (P>0.05). Study on the therapeutic mechanism of P-PRP: The absorbance (A) value, ALP activity, the relative mRNA expression of OPN and collagen type Ⅰ in group C were significantly higher than those in groups A and B (P<0.05), and those in group B were significantly higher than those in group A (P<0.05). The relative expression of MMP-9 protein and mRNA and the content of MMP-9 protein detected by ELISA in group B were significantly higher than those in groups A and C, while those in group C were significantly lower than those in group A (P<0.05). Western blot detection showed that the relative expression of PI3K, pAKT, and p-c-Jun protein in group B was significantly higher than those in groups A and C (P<0.05), but there was no significant difference between groups A and C (P>0.05). Conclusion P-PRP is superior to L-PRP for osteochondral injury of talus, which may be related to the inhibition of PI3K/AKT/AP-1 signaling pathway in the osteoblast, thereby reducing the secretion of MMP-9.
ObjectiveTo investigate evaluation and treatment of osteochondral injury of knee joint and its effectiveness.MethodsBetween January 2010 and January 2016, 17 patients with osteochondral injury of knee joint were admitted. There were 2 males and 15 females, with an average age of 19.3 years (range, 15-33 years). The causes of injury included the sprain in 14 cases and knee hyper-extension and varus due to violence in 3 cases. The osteochondral injury located at patella in 8 cases, lateral femoral condyle in 4 cases, medial femoral condyle in 1 case, and tibial plateau in 4 cases. There were 15 cases of fresh fractures and 2 cases of old fractures. The Lysholm score of the knee joint was 31.6±2.3. After open reduction of osteochondral fractures of 14 cases, the absorbable rods (9 cases), absorbable cartilage nail (3 cases), or absorbable sutures (2 cases) were selected for fixation. The osteochondral fractures at the medial tibial plateau margin (non-weight-bearing area) in 3 cases were removed.ResultsThe incision fat liquefaction occurred in 1 case after operation and healed after debridement. The other incisions had primary healing. All 17 patients were followed up 6 months to 2 years (mean, 13 months). Thirteen of 14 patients with internal fixation had good fractures healing without traumatic arthritis; 1 case of patella osteochondral fracture did not heal. Three patients with non-weight-bearing osteochondral removal had no narrowing of the medial joint space and traumatic arthritis during the follow-up. The Lysholm score of knee joint at 1 year after operation was 91.3±1.1, which significantly improved when compared with preoperative score (t=7.136, P=0.001).ConclusionFor the osteochondral injury of the knee joint, the osteochondral block with full-layer cancellous bone can be treated with open reduction and internal fixation; while osteochondral block with punctate cancellous bone can be directly remove.