Alterations in the Mechanical Properties of Patellar Tendons in Bone Sialoprotein- Null Mice

Introduction Bone sialoprotein (BSP) is a highly conserved multifunctional glycoprotein of the SIBLING family with a flexible structure and a variety of known roles, from cancer biology to tissue mineralization. BSP is present in a variety of mineralized tissues such as bone, dentin, and hypertrophic cartilage and is highly expressed in sites of active bone formation, during both development and fracture healing. BSP-null mice have been shown to exhibit a phenotype of lower body mass, shorter body length and shorter long bones. Although BSP is known to be expressed in some nonmineralized tissues, its effects on tendon are unknown. Therefore, the objective of this study was to use the BSP-null mouse model to assess the role of BSP on the biomechanical properties of the patellar tendon. We hypothesized that the absence of BSP would result in smaller and biomechanically inferior tendons, particularly in locations where tendon inserts into bone.