Advances in transgenic and gene-targeted mice have enabled tissue and cell-specific investigation of skeletal regeneration. While genetically modified animals offer incredible insights into the temporal and spatial importance of various molecules, the complexity and rapidity of healing renders studies of regenerative biology challenging. Herein, cells and extracellular mediators that play a key role in bone healing are reviewed. We will focus on recent studies that explore the origins and fates of various cells in the fracture environment.

A systematic review of the literature was conducted to identify studies that have investigated the mechanical, structural, or biologic effects that androgenic-anabolic steroids (AAS) have on tendons. Future studies investigating the use of AAS as a possible treatment for tendon injury/pathology are supported by reports suggesting that AAS may counteract the irreparable structural/functional changes that occur in the musculotendinous unit following rotator cuff tears, as well as studies suggesting the purported deleterious effects on tendon may be transient.

Advances in transgenic and gene-targeted mice have enabled tissue and cell-specific investigation of skeletal regeneration. While genetically modified animals offer incredible insights into the temporal and spatial importance of various molecules, the complexity and rapidity of healing renders studies of regenerative biology challenging. Herein, cells and extracellular mediators that play a key role in bone healing are reviewed. We will focus on recent studies that explore the origins and fates of various cells in the fracture environment.