**4. Platelet-Rich Plasma and joint degeneration**

*Regenerative Medicine*

**76**

**Variable type**

Composition

Activation

Others

**Table 1.** *Variables analyzed in the different classification systems.*

—

—

—

—

—

Activation

Activation

**Dohan [41]** Leukocytes

Fibrin

**Mishra [42]**

Platelets

Leukocytes

**PAW [43]**

Platelets

Leukocytes

Neutrophils

**PLRA [44]**

Platelets

Leukocytes

Neutrophils

Erythrocytes

Activation

—

Efficiency

Activation

Light

Method

Image guided

Spin

**DEPA [45]**

Platelets

Platelets

Leukocytes

Erythrocytes

Leukocytes

Erythrocytes

**MARSPILL [46]**
