TABLE 1.

Characteristics of the Included Studies^a

Lead Author (Year)	Study Type	Joint	Study Design	No. of Patients (Sex)	Patient Characteristicsb			Follow-up, mo	Outcome Measures	PRP Application and Harvest Methods	Main Results and Adverse Events
					Age, y	BMI	Lesion Size
Lee25 (2013)	RCT	Knee	MFX + PRP vs MFX only	PRP: 24 (14 M, 10 F) Control: 25 (15 M, 10 F)	PRP: 46 (42-47) Control: 46 (41-48)	PRP: 27 (22-29) Control: 28 (23-30)	PRP: <4 cm2 Control: <4 cm2	1, 6, 12, 24	IKDC subjective, VAS pain	Single injection of PRP (harvest method not specified) under arthroscopic view after MFX	At 2 y, better clinical results were seen in the PRP group than in the control group. In postarthroscopic findings, hardness and degree of elasticity were better in the PRP group.
Manunta28 (2014)	RCT	Knee	MFX + PRP vs MFX only	20 (9 M, 11 F)	30-55	<30	—	3, 6, 12	IKDC subjective, VAS pain	3 postoperative injections of PRP (GPS system II [Biomet Biologics])	Better functional outcome was seen in the PRP group, even at 12 mo, but the difference was not statistically significant.
Mancò27 (2016)	Prospective comparative	Knee	MFX + PRP vs MFX only	PRP: 14 Control: 13	52.4	—	—	3, 6, 12, 24	IKDC subjective, VAS pain, SF-36	Single injection of PRP (Cryofuge 6000i [Heraeus Instruments AHSI Spa]) under arthroscopic view after MFX	Better results were seen in the PRP group at the short-term follow-up. At 2-y follow-up, however, the clinical results of the 2 groups were similar.
Papalia39 (2016)	Retrospective comparative	Knee	MFX + PRP vs MFX only vs MFX + PRF	PRP: 19 (9 M, 10 F) Control: 17 (6 M, 11 F)	PRP: 52 ± 11 Control: 53 ± 9.8	—	PRP: 4.0 ± 0.3 cm2 Control: 4.0 ± 0.3 cm2	24, 60	IKDC subjective, VAS pain	3 postoperative injections of PRP (THT tube [Regen Lab SA])	Better clinical results were reported in the PRP and PRF groups. The PRF group showed better results than the PRP group at 2 y, with loss of significance at 5 y.
Guney12 (2015)	RCT	Ankle	MFX + PRP vs MFX only	PRP: 19 (7 M, 12 F) Control: 16 (9 M, 7 F)	PRP: 38.5 ± 12.7 Control: 42.8 ± 14.7	PRP: 27.8 ± 2.1 Control: 27.1 ± 3.1	PRP: <20 mm Control: <20 mm	16.2 (mean)	AOFAS, VAS pain, FAAM	Single injection of PRP (SmartPReP2 system [Harvest Autologous Hemobiologics]) 6-24 h after the operation	Improvement in both groups were noted, but better results were reported in the PRP group. One postoperatively, temporary neurapraxia occurred in the lateral dorsal branch of the superficial peroneal nerve that recovered spontaneously (treatment group not specified).
Görmeli11 (2015)	RCT	Ankle	MFX + PRP vs MFX only vs MFX + HA	PRP: 13 (5 M, 8 F) Control: 13 (8 M, 5 F)	PRP: 38.6 ± 9.1 Control: 40.3 ± 9.4	PRP: 30.5 ± 5.2 Control: 31.5 ± 4.5	PRP: 1.3 cm2 (0.5-1.4 cm2) Control: 1.2 cm2 (0.5-1.4 cm2)	15.3 (mean)	AOFAS, VAS pain	Single injection of PRP (SmartPReP2 system) 6-24 h after the operation	AOFAS and VAS pain scores were significantly improved in the PRP group vs HA and control groups.
Guney13 (2016)	Prospective comparative	Ankle	MFX + PRP vs MFX only vs mosaicplasty	PRP: 22 (11 M,11 F) Control: 19 (10 M, 9 F)	PRP: 43.9 ± 12.7 Control: 37.4 ± 16.0	—	—	42 (mean)	AOFAS, VAS pain, FAAM	Single injection of PRP (SmartPReP2 system) 6-24 h after the operation	All 3 groups had significant reduction in VAS scores. Better results were found in the mosaicplasty group. No difference was noted with regard to change in baseline AOFAS score.

^aControl refers to MFX only. AOFAS, American Orthopaedic Foot and Ankle Society score; BMI, body mass index; F, female; FAAM, Foot and Ankle Ability Measure; HA, hyaluronic acid; IKDC, International Knee Documentation Committee score; M, male; MFX, microfracture; PRF, platelet-rich fibrin; PRP, platelet-rich plasma; RCT, randomized controlled trial; SF-36, 36-Item Short Form Health Survey; VAS, visual analog scale for pain. Dashes indicate information not reported.

^bValues are expressed as mean with range or SD.