Abstract: Disclosed herein are materials and methods suitable for treating injured, damaged or diseased mineralized and non-mineralized skeletal tissues, including bones, joints, tendons, ligaments, cartilage and/or other non-mineralized skeletal tissues. The affected structure can be treated by contacting a surface of the skeletal element at or adjacent to or in the vicinity of an area of injury, damage or disease with an implantable material. The implantable material comprises a biocompatible matrix and cells and is in an amount effective to treat the affected structure. A composition comprising a biocompatible matrix and cells engrafted therein or thereon can be used to treat the affected structure. The composition can be a flexible planar material or a flowable composition.