Sponsor has decided there is not a business need for this study and is not required to complete.

The objectives of this study are to assess the safety and performance of the Sidus Stem-Free Shoulder Arthroplasty System in unilateral primary total shoulder arthroplasty.

The data collected from this study will serve the purpose of assessing safety and performance of the Sidus Shoulder.

Safety: Will be assessed by monitoring the frequency and incidence of adverse events (AE), serious adverse events (SAE), and unanticipated adverse device effects (UADE).

Performance: Will be determined by analyzing the implant survival, overall pain and functional performances (based on the ASES Patient Questionnaire and range of motion) and radiographic parameters of subjects who received the Sidus Shoulder. Implant survival will be based on removal or intended removal and determined using the observed component years (OCY) model as it is not anticipated that there will be adequate data at the 10 years follow-up to support Kaplan-Meier survivorship analysis. In the instance that there is sufficient data to perform Kaplan-Meier analysis, the analysis will be performed.

Inclusion Criteria:

• Patient must have previously participated in the Sidus IDE clinical trial.
• Patient must not have undergone revision of the Sidus shoulder.
• Patient must be able and willing to complete the protocol required follow-up.
• Patient must be able and willing to sign the IRB/EC approved informed consent.

Exclusion Criteria:

• Patient is a prisoner.
• Patient is a current alcohol or drug abuser.
• Uncooperative patient or patient with neurologic disorders who is incapable or unwilling to follow directions.
• Patient did not previously participate in the Sidus IDE clinical trial.
• Patient no longer has Sidus shoulder implanted.