ePoster #810 - ISHA Annual Scientific Meeting 2016

Role of Intravenous Gadolinium MRI in Revision Hip Arthroscopy

Michael Van Niekerk, MBChB, FRACS, Ngunguru NEW ZEALAND
Josip Chuck Cakic, MD, PhD, FCS(SA)Orth, MMed(Orth) WITS, Johannesburg, Gauteng SOUTH AFRICA

Life Fourways hospital, Johannesburg, SOUTH AFRICA

FDA Status Not Applicable

Summary: Role of intravenous gadolinium MRI scan to identify a cause for failed hip arthroscopy.

Introduction: Hip Arthoscopy is successful in relieving groin pain in the non-arthritic hip due to intra-articular pathology such as labral tear and Femoro-acetabular impingement. It however does sometimes fail to achieve this. There are several reasons for a failed hip Arthroscopy, of which the most common is inadequate resolution of the femoro-acetabular impingement. Other frequent causes are soft tissue impingement from iliopsoas and intra-articular scarring, or failing to address dysplasia. It is crucial to identify the correct cause before undertaking further directed treatment. We report on the role of MRI with intra-veneous Gadolinium followed by Arthrogram in identifying a cause of ongoing groin pain after hip arthroscopy. Method: We collected a case series of consecutive patients who underwent a MRI scan after an intra-veneous Gadolinium protocol, followed by an intra-articular Gadolinium MR arthrogram. A revision hip Arthroscopy procedure was then performed. Radiologic and intra-operative findings were compared and pre-and postoperative patient reported outcome scores were evaluated. The intra-venous Gadolinium scans were reported as Focal or General uptake and graded as low, intermediate or high signal intensity. Results: We had 12 patients, 10 female and 2 male. The mean age was 34 years (21 – 63 years). Mean pre-operative MAHORN scores were 27.35 and mean 6 months score was 44.29 (8 patients). 9 labral tears diagnosed on MRI and 6 tears repaired at surgery with an agreement of 75% between scans and intraoperative findings. Articular cartilage was reported as abnormal on 3 scans and found to be abnormal on 3 arthroscopies with at agreement of 58%. 6 Residual Cam lesions and 2 residual pincer lesions were addressed. Scans were grouped as between 0-6 months (3 scans) after primary arthroscopy, between 6 months and one year (5 scans) and after a year (4 scans). Scans performed under 6 months generally displayed high signal intensity in a focal pattern, with one also having a generalized uptake indicating a synovitis. 5 Scans performed between 6 months and one year demonstrated intermediate signal intensity with 2 displaying a generalized synovitis pattern. All except one scan performed after one year had low or no uptake. 11 scans was reported as scarring between labrum and capsule on MR arthrogram and 10 intraoperative reports confirmed scarring (91% agreement). Discussion: To our knowledge this is the first report on performing intra-venous gadolinium MRI scans in patients who had previously undergone hip arthroscopy in an attempt to identify a cause for ongoing groin discomfort. We found that the area of previous surgery displays high signal intensity under 6 months, intermediate intensity between 6 months and one year, and low signal intensity after a year, confirming no active scarring occurs after a year. Ideally this finding can be correlated in a group of asymptomatic post arthroscopy patients. We also noted, as previously reported, ongoing femora-acetabular impingement as a significant cause of ongoing groin pain. A significant (91%) proportion of patients had scarring between the labrum and capsule leading to adjacent labral tears in the zone between the free and fixed labrum.