Clinical Efficacy of Intra‐Articular Injection with P‐PRP Versus that of L‐PRP in Treating Knee Cartilage Lesion: A Randomized Controlled Trial

OBJECTIVE: Platelet‐rich plasma（PRP), with different concentration of leukocytes, may lead to varying effects in the treatment of cartilage lesions. So far, current research has not shown enough evidence on this. To evaluate the clinical efficacy and safety of intra‐articular injection with pure platelet‐rich plasma (P‐PRP) versus those of leukocyte platelet‐rich plasma (L‐PRP) in treating knee cartilage lesions, we conducted a double‐blind, randomized controlled clinical trial with a larger sample and longer follow‐up period. METHODS: From October 2019 to October 2020, 95 patients were invited to participate in our study, and 60 (63.2%) were randomized to P‐PRP (n = 30) or L‐PRP (n = 30) groups. Patients from the two groups were treated with knee intra‐articular injections of P‐PRP or L‐PRP. Visual analog scale (VAS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were assessed using an unpaired t‐test for independent samples preoperatively and at 6 weeks, 12 weeks, 6 months, and 12 months after intervention. RESULTS: We followed up 27 cases in the P‐PRP group and 26 cases in the L‐PRP group. No significant differences in VAS and WOMAC scores were found between the two groups before the intervention (p > 0.05). The WOMAC Pain and VAS‐Motions scores of the P‐PRP group were significantly lower than those of the L‐PRP group at 6 weeks after the intervention (p < 0.05). While the long‐term clinical efficacy of both injections was similar and weakened after 12 months, more adverse events were found in the L‐PRP group. CONCLUSIONS: The short‐term results demonstrate a positive effect in reducing pain and improving function in patients with knee cartilage lesions in the two groups. While the P‐PRP injection showed better clinical efficacy in the early phase of postoperative rehabilitation and resulted in fewer adverse events, long‐term follow‐up showed similar and weakened efficacy after 12 months. TRIAL REGISTRATION: ChiCTR1900026365. Registered on October 3, 2019, http://www.chictr.org.cn/showproj.aspx?proj=43911.