difficulty enrolling patients, no patient recruited

1. The course of AVN between Initial diagnosis and total hip replacement (THA) is analysed. The impact of early interventions versus conservative therapy in AVN before THA will be evaluated.
2. The short and long term outcomes of AVN patients undergoing THA with respect to complications, reoperations and quality of life are investigated. Potential risk factors for adverse outcomes will be investigated.

The study is to describe the course of avascular necrosis (AVN) of the femoral head from initial diagnosis and to collect data on treatment options and the further course in these cases. The duration from initial diagnosis of AVN to joint replacement as total hip arthroplasty (THA) will be analysed and the course after joint replacement with potential short- and long-term complications will be evaluated.

The impact of THA after AVN on activities of daily living will be assessed by Euroquol 5 Dimensions (EQ-5D-5L) and Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaires.

Inclusion Criteria:

• MRI of the hip available from diagnosis at the USB or KSBL Liestal
• Informed Consent

Exclusion Criteria:

• Insufficient knowledge of project languages (English, German, French)

Population 1: Patients with a first AVN-related contact (initial or confirmed diagnosis) at the USB or KSBL Liestal in the years between 1999-2006.

Population 2: Patients with a THA because of AVN at the USB or KSBL Liestal in the years 2000-2007.