Spinal implants and methods to repair annular defects in intervertebral discs and provide dynamic stability to the spine near a repaired disc are described. Some implants include head and tail portions. In some embodiments, the head portion is enlarged relative to the tail portion. Some head portions and tail portions are adapted to support adjacent vertebrae to resist intervertebral disc collapse. Head portions provide a spacer function to maintain separation between adjacent vertebrae. In some implants, a tail portion engages end plates of adjacent vertebrae to resist extrusion of the implant from the intervertebral space. The tail portion of some implants includes a tail flange (in some embodiments of similar diameter to the head portion) abutting extradiscal lips of adjacent vertebrae and resisting forces tending to push the implant deeper into the intervertebral space. Some embodiments are compliant, while some include bone-compaction holes to stabilize the implant in situ.