Table 3 Summary of animal studies of platelet-rich plasma for treatment of cartilage defects

Rabbit osteochondral defect in trochlea

4 mm diameter, 3 mm depth

Untreated; double-spun PRP activated by CaCl₂; PRP gel + ADSCs; PRP gel + BMSCs

PRP group yielded better macroscopic and histological results than untreated, but worse than PRP with cells

[21]

Rabbit osteochondral defect in trochlea

5 mm diameter, 4 mm depth

Untreated; double-spun PRP activated by thrombin and CaCl₂ + PLGA; PLGA

Macroscopic examination, micro-CT, and histology of newly formed osteochondral tissue differed significantly between PRP-treated and untreated groups

[75]

Rabbit osteochondral defect in trochlea

4 mm diameter, 3 mm depth

Untreated; collagen scaffold alone or with doule-spun inactivated PRP

PRP-collagen group had highest histological scores and most GAG content; mechanical property was only better than that in the untreated group.

[76]

Sheep osteochondral defect in femoral condyle

7 mm diameter, 9 mm depth

Untreated; collagen-hydroxyapatite scaffold alone or with L-PRP activated by CaCl₂

Good integration of the chondral surface in both treatment groups; better osteochondral reconstruction in the group treated with scaffold alone than with PRP

[77]

Goat osteochondral defect in trochlea

6 mm diameter, 0.8 mm depth

Engineered cartilage implants with periosteal flap or L-PRP or human fibrin

PRP and human fibrin glue interfered with retention of the implants and integration with adjacent cartilage

[78]

Sheep chondral defect in femoral condyle

8 mm diameter, cartilage only

Microfracture alone or with five weekly P-PRP intra-articular injections

PRP enhanced the macroscopic, histological and biomechanical characteristics at 3 months, 6 months and 12 months, but did not produce hyaline cartilage

[79]

Sheep chondral defect in femoral condyle

8 mm diameter, cartilage only

Microfracture alone, with single P-PRP injection or with P-PRP and fibrin gel filling up the defects

PRP with fibrin gel yielded the best histological results and biomechanical results, close to those of the normal cartilage, but still did not produce hyaline cartilage

[80]