Chronic soft tissues defects can extend into the fat layer or even deeper and can cause functional disadvantages. Split-thickness skin grafts (STSGs) used to cover these wounds have varying success rates. To improve wound healing in chronic wounds the authors have studied the application of autologous platelet concentrates in a human keratinocyte culture model in vitro and in a combination with surgical procedures in vivo as second line therapy in patients with initially failed wound closure.

For in vitro testing on keratinocytes a platelet-mediator concentrate (PMC) was processed with a commercially available bed-side system (ATR®, Curasan, Germany). In a clinical study soft tissue defects (n=5) were treated using a combination of surgical debridement and autologous platelet rich plasma (PRP). Time of healing as determined by epithelization as well as Laser Doppler Imaging to visualize blood flow were analyzed. Additionally, changes in "ease of surgical wound closure" were determined. Finally, the quality of life of patients was assessed using a validated questionnaire.

Inclusion Criteria:

• exposed tendons, ligaments or bone for >3 weeks
• no healing tendency

Exclusion Criteria:

• sepsis
• intensive care treatment
• continuous smoking
• pregnancy or breast feeding women
• participants of other studies.