Ascension® Post- Approval Study; PyroCarbon Metacarpophalangeal Total Joint Prosthesis

Inclusion Criteria: * Indications consistent with the FDA approved Indications For Use: Index, long, ring, or small finger metacarpophalangeal (MCP) joints that exhibit symptoms of pain, limited motion, or inadequate bony alignment (i.e., subluxation/dislocation) secondary to articular destruction or degenerative disease related to rheumatoid arthritis, systemic lupus erythematosus, osteoarthritis, or post-traumatic arthritis where soft tissue reconstruction can provide adequate stabilization * Willing to participate in the study * Signed an Informed Consent Form * The means and ability to return for all required study visits * Are not transient Exclusion Criteria: Patients who have any of the following contraindications will be excluded from the study: * Inadequate bone stock at the implantation site * Active infection in the MCP joint * Nonfunctioning and irreparable MCP musculotendinous system * Physical interference with or by other prostheses during implantation or use * Procedures requiring modification of the prosthesis * Skin, bone, circulatory and/or neurological deficiency at the implantation site