Validation of a dynamic in-situ and imaging-based computer model for the detection of a femoro-acetabular impingement syndrome to differentiate between intra- and extraarticular pathologies and evaluate their impact on the patient's restrictions.

• Applicant: Dr. Nils Becker
• Subject Area: Orthopaedics, Traumatology, Reconstructive Surgery
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 547256202

The femoro-acetabular impingement syndrome (FAIS) is an acquired disorder of the hip joint, which is mainly responsible for the early onset osteoarthritis in young patients. It leads to a bony conflict between the acetabular rim and the femoral head-neck junction causing structural damages due to the direct contact or dislocations phenomena (contre-coup). The FAIS is classified into three types: - The FAIS type cam is defined by an offset reduction of the femoral head-neck junction and is predominantly found in male patients. This type leads especially to cartilage damage and results in 25% of the suffered cases to osteoarthritis within 20 years. -The FAIS type pincer is a local or generalized overhanging acetabular rim and leads in most cases to labral lesions. This type is predominantly seen in female patients. -The mixed type containing disorders of the type cam and pincer. The FAIS has been considered the cause of hip pain in up to 95% of athletes and up to 50% of the general population. Because FAIS finally results in osteoarthritis, it is important to detect and treat the pathology, otherwise a total hip replacement could be required. However, not in each case pain or restrictions are present. In a study of 44 asymptomatic volunteers, magnetic resonance imaging (MRI) showed a labral tear in 69% of hips, chondral defect in 24%, ligamentum teres tear in 2.2%, labral/paralabral cyst in 13%, acetabular bone edema in 11%, fibrocystic changes of femoral head-neck junction in 22%, subchondral cyst in 16%, and osseous bumps in 20% of the cases. MRI and CT scan are performed in the supine position. However, FAI is a dynamic process that occurs during motions, especially in deep flexion which is not possible in static CT scan or MRI imaging. Hence a new approach is required to diagnose the concordant and discordant pain in patients with FAI diagnosis to formulate the operative or nonoperative treatment. Currently, there are no in-situ computer models to study FAI pain in a more dynamic approach. The focus of this proposal is to address the following knowledge gap: -Can a new FAI computer model be created, verified and validated to use MRI/CT scan with details regarding anatomical structures and bony/soft tissue lesions and the use of real time motion capture data? - Preoperatively, can this computer model be validated among patients who have been diagnosed with FAI and considered for FAI surgery based on clinical findings and imaging studies? -Postoperatively, can this computer model show no impingement among patients who report significant pain relief during hip ROM (successful surgery) but conversely show residual impingement or cartilage damage among patients who report pain (unsuccessful surgery)?

• DFG Programme: WBP Fellowship
• International Connection: USA
• Hosts: Professor Dr. Aidin Eslam-Pour; Professor Dr. Lee Eric Rubin; Professor Dr. Daniel Wiznia