Proof of concept: hip joint damage occurs at the zone of femoroacetabular impingement (FAI) in an experimental FAI sheep model.

Zurmühle, Corinne Andrea; Schmaranzer, Florian; Nuss, K; Wolfer, N; Ryan, M K; Zheng, G; von Rechenberg, B; Tannast, Moritz (2019). Proof of concept: hip joint damage occurs at the zone of femoroacetabular impingement (FAI) in an experimental FAI sheep model. Osteoarthritis and cartilage, 27(7), pp. 1075-1083. Elsevier 10.1016/j.joca.2019.04.001

[img] Text
1-s2.0-S1063458419309215-main.pdf - Published Version
Restricted to registered users only
Available under License Publisher holds Copyright.

Download (2MB) | Request a copy

OBJECTIVE In ovine hips chondrolabral damage as seen in cam-type femoroacetabular impingement (FAI) can be induced via an intertrochanteric varus osteotomy. However, it is yet to proven whether the observed cartilage damage is caused by a dynamic cam type impingement. Thus we asked, (1) whether actual cartilage damage observed after FAI induction in ovine hips occurs at the predicted, computed zone of FAI; (2) whether the extent of cartilage damage increases with ambulation time in this animal model? DESIGN In this experimental, controlled, comparative study 20 sheep underwent unilateral FAI induction through an intertrochanteric varus osteotomy. Preoperatively sheep underwent computed tomography to generate three-dimensional models of the osseous pelvis and femur. The models were used to predict impingement zones before and after simulated varus osteotomy using range of motion (ROM) analysis. Sheep were sacrificed after 14-40 weeks of ambulation. At sacrifice cartilage was inspected and (1) location of actual damage and computed impingement zones were compared; (2) Cartilage damage was compared between short- and long ambulation groups. RESULTS (1) The average location and the extent of peripheral and central cartilage lesions did not differ with the computed impingement zones (all P > 0.05). (2) Grades of central, posterior cartilage damage were more severe in the long-compared to the short ambulation group (2.2 ± 1.8 vs 0.4 ± 0.5; P = 0.030). CONCLUSIONS In this experimental ovine FAI model the surgical induction of an osseous impingement conflict between the femur and acetabulum causes cartilage damage at the zone of simulated FAI.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Department of Orthopaedic, Plastic and Hand Surgery (DOPH) > Clinic of Orthopaedic Surgery

UniBE Contributor:

Zurmühle, Corinne Andrea; Schmaranzer, Florian and Tannast, Moritz


600 Technology > 610 Medicine & health








Kathrin Aeschlimann

Date Deposited:

31 Oct 2019 09:52

Last Modified:

31 Oct 2019 10:00

Publisher DOI:


PubMed ID:


Uncontrolled Keywords:

CT impingement simulation Cam deformity Femoroacetabular impingement Hip preservation surgery Osteoarthritis Sheep hip model




Actions (login required)

Edit item Edit item
Provide Feedback