Which stage is characterized by full-thickness tissue loss with exposed bone, muscle, or tendon?

• A. Stage 2 pressure ulcer
• B. Stage 4 pressure ulcer
• C. Stage 3 pressure injury
• D. Unstageable pressure ulcer

Answer: (B)

Staging is based on how deep the tissue damage goes and what’s exposed in the wound bed. When the injury reaches full-thickness loss, the skin is gone through to deeper layers, and if bone, tendon, or muscle are actually exposed, that signals the deepest level of tissue destruction—Stage IV. In Stage III, you have full-thickness loss as well, but the wound bed shows subcutaneous tissue (adipose, for example) without exposure of bone, tendon, or muscle. Stage II is only partial-thickness loss involving the epidermis and/or dermis, and unstageable means the depth can’t be seen because the wound bed is obscured by slough or eschar. So the description of full-thickness loss with exposed bone, muscle, or tendon fits Stage IV.