Platelet-rich plasma in the treatment of delayed union and nonunion fractures: An umbrella meta-analysis.

Background: Long bone fractures may exhibit nonunion/delayed union and the precise mechanism underlying this devastating condition remain unknown. More recently, a series of meta-analyses have examined the effect of local administration of platelet-rich plasma (PRP) in patients suffering from nonunion/delayed union fractures; however, the conclusions of available meta-analyses have remained debatable. This umbrella meta-analysis was performed to synthesize and recalculate available evidence to assess the certainty of the effect of PRP on nonunion/delayed union fractures.