BACKGROUND: Chronic lateral elbow epicondylitis is a tendinosis with 
angiofibrolastic degeneration of the wrist extensors' origin. Healing of this 
lesion is reported with the use of autologous blood as well as with 
platelet-rich plasma (PRP).
PURPOSE: A comparative study of these 2 treatments was conducted in an effort to 
investigate the possible advantages of PRP.
STUDY DESIGN: Randomized controlled trial; Level of evidence, 1.
METHODS: Twenty-eight patients were divided equally into 2 groups, after blocked 
randomization. Group A was treated with a single injection of 3 mL of autologous 
blood and group B with 3 mL of PRP under ultrasound guidance. A standardized 
program of eccentric muscle strengthening was followed by all patients in both 
groups. Evaluation using a pain visual analog scale (VAS) and Liverpool elbow 
score was performed at 6 weeks, 3 months, and 6 months.
RESULTS: The VAS score improvement was larger in group B at every follow-up 
interval but the difference was statistically significant only at 6 weeks, when 
mean improvement was 3.8 points (95% confidence interval [CI], 3.1-4.5) in group 
B (61.47% improvement) and 2.5 points (95% CI, 1.9-3.1) in group A (41.6% 
improvement) (P < .05). No statistically significant difference was noted 
between groups regarding Liverpool elbow score.
CONCLUSION: Regarding pain reduction, PRP treatment seems to be an effective 
treatment for chronic lateral elbow epicondylitis and superior to autologous 
blood in the short term. Defining details of indications, best PRP 
concentration, number and time of injections, as well as rehabilitation protocol 
might increase the method's effectiveness. Additionally, the possibility of cost 
reduction of the method might justify the use of PRP over autologous whole blood 
for chronic or refractory tennis elbow.