[Case-control study on local injection of autoallergic platelet rich plasma or whole blood for the treatment of tennis elbow].

OBJECTIVE: To compare therapeutic effects of local injection with autoallergic platelet rich plasma (PRP) or autoallergic whole blood (AWB) for the treatment of chronic tennis elbow.

METHODS: From January 2011 to January 2014, 40 patients with chronic tennis elbow were divided into 2 groups, 20 cases in each group: PRP group and AWB group. There were 20 patients in PRP group treated with local injection of autoallergic platelet rich plasma, including 5 males and 15 females, with an average age of (47.50 ± 9.86) years old; and the average course of disease was (4.67 ± 3.27) months. Among the 20 patients in AWB group treated with local injection of autoallergic whole blood, 3 patients were male and 17 patients were female, with an average age of (46.50 ± 9.96) years old;and the average course of disease was (4.53 ± 2.27) months. The elbow joint was fixed with elastic stockings after injection. All the patients were guided to do strengthening and extension exercises during the follow-up period. Visual analog scale (VAS), Mayo scores for elbow and pressure pain threshold (PPT) were used to evaluate clinical effects after injection immediately and 4,8 weeks after treatment. Results:All the patients were followed up,there were no infections and swelling occurred. The VAS, Mayo and PPT scores of patients in PRP group were improved from pre-therapy 7.22 ± 1.32, 56.71 ± 10.90 and 17.47 ± 4.62 to 2.73 ± 1.00, 91.59 ± 6.95 and 21.35 ± 4.80 respectively 8 weeks after treatment. The VAS, Mayo and PPT scores of patients in AWB group were improved from pre-therapy 7.16 ±1.27, 54.72 ± 8.36 and 17.06 ± 4.83 to 3.81 ± 1.36, 82.06 ± 7.89 and 20.12 ± 4.97 respectively 8 weeks after treatment. All the pain and functional variables including VAS, PPT, and Mayo scores were improved significantly in both groups 4 weeks after injection. On the 4th week after injection, there was no statistically significant difference in PPT between two groups; while the VAS and Mayo score of AWB group were lower than those of PRP group. On the 8th week after injection, the VAS of AWB group was higher than that of PRP group; but the Mayo and PPT scores of AWB group were lower than those of PRP group.

CONCLUSION: PRP and AWB injections are both effective to treat chronic lateral epicondylitis. Compared with AWB injection, PRP injection may be more effective in releasing pain and improving function for a longer time.