ePoster #716 - ISHA Annual Scientific Meeting 2016

Can Soft Tissue Structures Differentiate Between Dysplasia And Cam-Femoroacetabular Impingement Of The Hip?

Anne Le Bouthillier, BSc, Ottawa, Ontario CANADA
Paul Beaule, MD, FRCSC, Ottawa, Ontario CANADA
Etienne Belzile, MD, FRCS, Quebec CANADA
Kawan Rakhra
Ryan Foster, MD, FRCPC, Ottawa, Ontario CANADA

University of Ottawa/Ottawa Hospital, Ottawa, Ontario, CANADA

FDA Status Not Applicable

Summary: Enlarged rectus femoris and thicker hip capsule in dysplastic hips may serve as preoperative discriminators, in addition to traditional features of enlarged labrum.

Abstract:
BACKGROUND: Clinically, it may be challenging to differentiate various etiologies of hip dysfunction. Very few studies have looked at soft tissue structures as preoperative discriminators to better predict the underlying etiology of joint disease in various hip conditions.


PURPOSE: To determine whether MR arthrography [MRA] assessment of soft tissue structures of the hip can preoperatively predict the underlying etiology of joint disease.


METHODS: Fifty-seven patients who underwent preoperative MRA and corrective hip surgery were retrospectively identified yielding three groups: 17 with hip dysplasia [DDH] (11F, 6M; mean age 35.1 yrs, range 19.6-53.6); 20 with isolated labral tears [LT] (17F, 3M; mean age 38.4 yrs, range 15.2-62.1) and 20 with cam-type femoroacetabular impingement [FAI] (11F, 9M; mean age 38.8yrs, range 18.9-51.2). Measurements of the hip labral length, capsule thickness, and psoas, rectus femoris and gluteal muscle dimensions were performed, with normalization of the values for statistical analysis.


RESULTS: The superior labral length was significantly greater in the DDH group (normalized value [NV]: 0.30) compared to the FAI group (NV: 0.25, p<0.05). Additionally, the superior(12 o’clock) capsular thickness (NV: 0.24), was significantly greater compared to the LT group (NV: 0.15, p<0.05) and the FAI group (NV: 0.16, p<0.05). The DDH group also had a significantly greater anterior(3 o’clock) capsular thickness (NV: 0.18) compared to the LT group (NV: 0.13, p<0.05). The transverse dimension of the rectus femoris was larger in the DDH group (NV: 1.39) compared to the FAI group (NV: 1.14, p<0.05).


CONCLUSION: Enlarged rectus femoris and thicker hip capsule in dysplastic hips may serve as preoperative discriminators, in addition to traditional features of enlarged labrum.