The Unknown CasesThe Unknown Cases

Texas Radiological Society Texas Radiological Society 9292ndnd Annual Scientific Meeting Annual Scientific Meeting

San Antonio, TX; April 1-3, 2005San Antonio, TX; April 1-3, 2005

Justin Q. Ly, MD*+Douglas P. Beall, MD^Ernesto Torres, MD+

Daniel H. Duffy*

Department of Radiology and Nuclear MedicineDepartment of Radiology and Nuclear MedicineWilford Hall Medical Center/SAUSHEC Radiology*Wilford Hall Medical Center/SAUSHEC Radiology*

Oklahoma University Health Sciences Center^Oklahoma University Health Sciences Center^Brooke Army Medical Center+Brooke Army Medical Center+

55 year old man55 year old man with chronic hip pain.  with chronic hip pain. 

Pain worse when hip is "in the side kicking position". Pain worse when hip is "in the side kicking position". 

On physical exam, pain exacerbated by flexion, adduction, On physical exam, pain exacerbated by flexion, adduction, and internal rotation.and internal rotation.

CASE 7CASE 7

FindingsFindings

XR-loss of normal indentation at left superior XR-loss of normal indentation at left superior femoral head/neck junction (“pistol grip” femoral head/neck junction (“pistol grip” appearance), focal calcification at the appearance), focal calcification at the anterosuperior aspect of left hip joint is likely anterosuperior aspect of left hip joint is likely related to chronic microtraumarelated to chronic microtrauma

Fluid-sensitive sequence coronal MR image shows Fluid-sensitive sequence coronal MR image shows focal chondral defect just medial to superior labral focal chondral defect just medial to superior labral base, torn labrum, adjacent focal subchondral base, torn labrum, adjacent focal subchondral marrow edema, and subtle evidence of marrow edema, and subtle evidence of impingement at left femoral head-neck junctionimpingement at left femoral head-neck junction

Diagnosis?Diagnosis?

Femoral Acetabular Femoral Acetabular ImpingementImpingement

PISTOL GRIP DEFORMITY (loss of normal degree of indentation @ superior head/neck-YELLOW ARROW) WHICH IS LIKELY CONTRIBUTING TO FAI

Coronal T2-weighted MR image of the hip joint shows cartilage damage (chondral defects) in the superiolateral portion of the hip joint (small white arrows). There is also an associated acetabular labral tear (black arrow). These findings are typical of those seen in patients with FAI.

Femoral Acetabular ImpingementFemoral Acetabular Impingement

Impingement of femoral head-neck jxn against adjacent Impingement of femoral head-neck jxn against adjacent acetabulumacetabulum

Can result in tearing of labrum and progressive damage to articular Can result in tearing of labrum and progressive damage to articular cartilage cartilage

Repetitive microtraumaRepetitive microtrauma Precursor to early onset OA.Precursor to early onset OA. Two basic mechanismsTwo basic mechanisms

– Cam impingement:Cam impingement: squeezing or jamming of a reduced concavity anterolateral femoral head-neck jxn into acetabulum during motion

– Pincer impingement:Pincer impingement: direct linear contact between the femoral head-neck junction and a limited portion of the acetabular rim.

– Post traumatic or dysplastic conditions may predispose to hip impingement

GROIN / POST HIP PAINGROIN / POST HIP PAIN

FAIFAI

IMAGING: “pisto grip” deformity, IMAGING: “pisto grip” deformity, anterosuperior anterosuperior acetabular labral tears, impaction injury to adj acetabular labral tears, impaction injury to adj anterolateral femoral head/neck junction, lateral anterolateral femoral head/neck junction, lateral acetabular cartilage damageacetabular cartilage damage, abnormal femoral head to , abnormal femoral head to neck ratio, convex appearing femoral head-neck jxn that neck ratio, convex appearing femoral head-neck jxn that may be quantified w/ may be quantified w/ angle measurement and angle measurement and DJDDJD– paralabral cysts and synovial herniation pitsparalabral cysts and synovial herniation pits

RECOGNIZE EARLY AS SURG TX AVAILABLE: RECOGNIZE EARLY AS SURG TX AVAILABLE: osteotomy, an osteoplasty, or a combination of both osteotomy, an osteoplasty, or a combination of both

REFERENCESREFERENCESIto K, Minka MA II, Leunig M, Werlen S, Ganz R. Femoracetabular impingement and the cam-effect: an MRI-Ito K, Minka MA II, Leunig M, Werlen S, Ganz R. Femoracetabular impingement and the cam-effect: an MRI-based quantitative anatomical study of the femoral head-neck offset. based quantitative anatomical study of the femoral head-neck offset. J Bone Joint Surg Br J Bone Joint Surg Br 2001; 83:171-176.2001; 83:171-176.H.P. Notzli, T.F. Wyss, C.H. Stoecklin, M.R. Schmid, K Treiber, J. Hodler. The contour of the femoral head-H.P. Notzli, T.F. Wyss, C.H. Stoecklin, M.R. Schmid, K Treiber, J. Hodler. The contour of the femoral head-neck junction as a predictor for the risk of anterior impingement. neck junction as a predictor for the risk of anterior impingement. J Bone Joint Surg BrJ Bone Joint Surg Br 2002; 84:556-560. 2002; 84:556-560.Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular Impingement. Ganz R, Parvizi J, Beck M, Leunig M, Notzli H, Siebenrock KA. Femoroacetabular Impingement. Clin OrthopClin Orthop. . 2003;417:112-1202003;417:112-120Wagner S, Hofstetter W, Chiquet M, Mainil-Varlet P, Stauffer E, Ganz R, Siebenrock KA. Early osteoarthritic Wagner S, Hofstetter W, Chiquet M, Mainil-Varlet P, Stauffer E, Ganz R, Siebenrock KA. Early osteoarthritic changes of human femoral head cartilage subsequent to femoro-acetabular impingement. changes of human femoral head cartilage subsequent to femoro-acetabular impingement. Osteoarthritis Osteoarthritis CartilageCartilage. 2003;11(7):508-18.. 2003;11(7):508-18.