Wound duration and healing rates: cause or effect?

Multiple factors affect the likelihood of a wound healing. One of these factors, wound duration, is well known to be related to healing rates, with numerous publications showing that older wounds are less likely to heal. However, disentangling the effect of this factor on wound healing rates is complex. Is this simply an observation of the obvious; wounds of longer duration will by definition be harder to heal? Or does time represent an independent factor, implying that should treatments be given earlier in the disease process, better outcomes may result? This review summarizes the available evidence of the effects of wound duration on healing rates and examines potential biological aberrations identified in chronic wounds, which may be significant in making chronic wounds difficult to heal. Wounds of longer duration are associated with excessive inflammation, fibroblast senescence, and alterations in wound bed flora, which appears to have a temporal relationship. Early and aggressive treatment of ulcers that fail to respond to standard care may well aid in reducing the burden of wounds that become chronic.