Table 1.

Demographics, Characteristics, and Definitions

Author	Study type	Blinding	Treatment methods compared	PRP group vs. control group	No. of PRP injections	Outcome measures in study	Follow-up	Inclusion criteria	Exclusion criteria
Dragoo et al.12)	Randomised controlled trial	Double blinded	PRP injections vs. ultrasound guided dry needling (plus standardized eccentric exercises)	PRP (n=9), control (n=12)	1	Victorian Institute of Sports Assessment score Pain visual analogue scale Tegner activity scale Lysholm knee scale Short-form questionnaire	3, 6, 9, and 12 weeks and >6 months	Patellar tendinosis with persistence of symptoms after 6 weeks (12 sessions) of physical therapy with eccentric exercise Confirmed by magnetic resonance imaging Aged >18	Previous injection or surgery in the affected knee Inability to complete patient reported outcome surveys
Vatrano et al.13)	Randomised controlled trial	Single blinded	PRP injections vs. focused extracorporeal shock wave therapy (plus a standardized stretching and muscle strengthening protocol)	PRP (n=23), control (n=23)	2 (1 per week for 2 weeks)	Victorian Institute of Sports Assessment score Pain visual analogue scale Modified Blazina scale	2, 6, and 12 months	Chronic unilateral patellar tendinosis with symptoms >6 months and refractory to nonsurgical management “Washout period” of 12 weeks between any non-operative therapy and inclusion in the study Confirmed by ultrasound scan Athletic participants Aged 18–50	Bilateral complaints Signs or symptoms of other coexisting knee lesions; knee surgery or steroid injections within 3 months Signs of disorders Therapy with anticoagulants-antiaggregants; platelet values of fewer than 150,000/mm3 Pregnancy

PRP: platelet-rich plasma.