The aim of this observational study is to collect and evaluate the current clinical experience gained from the Hindfoot Arthrodesis Nail (HAN) for ankle and hindfoot fusions.

The HAN (Synthes) is a newly designed, titanium nail for trans-calcaneal, retrograde hindfoot fusion. The lateral bend allows an entry site in the center of the lateral column of the calcaneus, thus minimizing the risk of iatrogenic injury of the plantar neurovascular bundle.

Inclusion Criteria:

• HAN fusion procedure ≥ 12 months before entering the study.
• Written or oral informed consent.

Eligible patients will be identified from the study sites' medical records, information systems, and OR logs. The responsible local investigator or co-investigator at each study site will approach patients by letter or phone, and inquire about their interest in participating in this study.