Ascension PyroCarbon Radial Head Study

This investigation will include 179 patients (119 study devices and 60 control devices) enrolled at 15 active centers. In addition a subset of 24 RA patients will be enrolled and analyzed separately. The trial is designed as a randomized, non-inferiority study comparing results of the CMRH to results of the MRH. This will be a multi-site study with all patients either receiving the CMRH or the MRH. Sequential enrollment of all patients meeting inclusion criteria and agreeing to be in the study will be enrolled. The patients will sign an informed consent agreeing to accept either the investigational or control device. In addition, the surgeon will not know which device the patient is to receive until the day of surgery in an attempt to further reduce bias. The surgeon will open an envelope at the time of surgery to determine if a CMRH or MRH will be implanted. Additional efforts to eliminate bias in the study will include a final radiographic analysis by an independent observer experienced in reporting on orthopedic devices. The independent reviewer will grade the surgical implant and determine radiographic success/failure for each patient. Implants will be assigned to patients at the clinical sites in a block randomization fashion. The randomization will be site specific. At a given site, each consecutive block of six enrolled patients to be treated will receive random assignments of CMRH or MRH at a 2:1. The randomization schedule is generated by computer (NQuery) and is produced in blocks of 6, where 4 are study devices and 2 are control devices.