Patient Specific Talus Spacer Post Approval Study

This is a Humanitarian Device Exemption (HDE) approved device called the Patient Specific Talus Spacer. This is a post approval study to determine the safety and probable benefit of the Patient Specific Talus Spacer in commercial use. The Patient Specific Talus Spacer is a solid polished replica of the patient's bone to allow the patient to regain motion and reduce pain.

Inclusion criteria

• Subject plans to undergo implantation of the Patient Specific Talus Spacer for avascular necrosis of the ankle joint independent of this research protocol;
• Avascular necrosis of the ankle joint;
• Age 21 years old or older;
• Subject has good general health; and
• Subject signs a written informed consent form (ICF) prior to the surgical procedure.

Exclusion criteria

• Presence of any contraindication identified in the device Instructions for Use;
• Surgeon determines that the patient is not appropriate for the Talus Spacer procedure based on the device IFU (including the enumerated Warnings and Precautions);
• Based on the medical opinion of the surgeon, the patient is not appropriate for the Talus Spacer procedure;
• For female subjects, pregnancy;
• Active systemic disease, such as AIDS, HIV, or active infection;
• Active infection or the skin is compromised at the surgical site; and
• Systemic disease that would affect the subject's welfare;
• Is a prisoner, incarcerated, or has been coerced to participate in the study that could impact the validity of results;
• Is currently participating in an investigational therapy (device and/or pharmaceutical) within 30 days prior to entering the study or such treatment is planned during the time course of follow-up.
• If the Sponsor has notified the site that 30 subjects have been enrolled in the study with a Cobalt Chromium Patient Specific Talus Spacer, and the surgeon believes that a Cobalt Chromium Patient Specific Talus Spacer is the best option for the patient.
• If the Sponsor has notified the site that 30 subjects have been enrolled in the study with a Titanium (Ti6Al4V) with Titanium Nitride (TiN) coating Patient Specific Talus Spacer, and the surgeon believes that a Titanium (Ti6Al4V) with Titanium Nitride (TiN) coating Patient Specific Talus Spacer is the best option for the patient.