Abstract: Objective   To observe more cases and indexs of platelet rich fibrin (PRF) application on chronic wounds,which provide solid basis for the application of PRF on the treatment of chronic wounds.  Methods   86 patients with chronic wounds treated in our hospital from January 2014 to January 2022 were selected.The odd and even number grouping was used to guide the patients to draw numbers by themselves.The patients with odd numbers were classified as the control group (routine treatment),and the patients with even numbers were classified as the observation group (PRF treatment).The number of patients in each group was 43.The infection control,wound area change,VAS score,push score,quality of life score,cost and time after treatment were observed before and after treatment,and the therapeutic effect of PRF was summarized.   Results   Before treatment in the observation group and the control group TNF-α Level,IL-2,IL-8,granulation tissue score,wound area,VAS score,push score,negative emotion score and quality of life score were not statistically significant (P>0.05).There was significant difference between the two groups after treatment and before treatment (P<0.05).There was significant statistical significance between the two groups after treatment (P<0.05).There was significant difference in treatment cost and time between the two groups (P<0.05).The therapeutic effect of the two groups was statistically significant (P<0.05).  Conclusion   The application of PRF on the treatment of chronic wounds can effectively reduce the level of inflammatory factors in patients,control the degree of infection,reduce the wound area,alleviate the pain degree of patients and improve the quality of life.At the same time,it can effectively reduce the treatment cost and wound healing time.

Key words: platelet rich fibrin, chronic wounds, chronic refractory wounds