Hip and Thigh Ultrasound Disclosures: with MRI Correlation • Consultant: Bioclinica • Advisory Board: GE, Philips Jon A. Jacobson, M.D. • Book Royalties: Elsevier Professor of Radiology • Not relevant to this talk Director, Division of Musculoskeletal Radiology University of Michigan Note: all images from the textbook Fundamentals of Musculoskeletal Ultrasound are copyrighted by Elsevier Inc. Hip: anterior recess Pathology: • Anterior and posterior layers • Joint abnormalities – Fibrous tissue + minute layer of synovium • Bursal pathology – Hyperechoic Radiology – Each 2 - 4 mm thick 1999; 210:499 • Muscle and tendon injury • Snapping hip syndrome • Miscellaneous pathology Hip: anterior recess Hip Effusion: • Separation of anterior and posterior layers1 • Capsule distention at femoral neck > 7 mm or Anterior difference of 1 mm from opposite side2 Posterior Femur • Extension & abduction improves visualization3 • Do not internally rotate hip: capsule thickens 1Radiology 1999; 210:449 2Scand J Rheumatology 1989; 18:113 3Acta Radiologica 1997; 38:867 1 Hip Joint: septic effusion Hip Effusion: misconception • It is incorrect to assume that joint fluid may not be seen anterior due to gravity • Native hip: joint fluid distributes around * femoral neck • In no cases was fluid only seen posterior FH * Neck • Exception: after hip surgery * * Long Axis Moss et al. Radiology 1998; 208:43 Hip Joint: aseptic effusion Hip Joint: aseptic effusion FH * Neck Acet FH * Neck Femoral Neck Sagittal Axial Hip Effusion: Pitfall: capsule thickening • Cannot predict • Internal rotation of hip: infection by ultrasound – Anterior hip capsule • Negative power color * – Thicker, convex anterior Doppler does not exclude infection* Head * • Guided aspiration Neck External Rotation Internal Rotation * AJR 1998; 206:731 2 Pigmented Villonodular Juvenile Idiopathic Arthritis Synovitis Head Head Erosion Labral Tear and Paralabral Cyst Hip Labrum Chondrocalcinosis • Normal: – Hyperechoic, triangular • Degeneration: hypoechoic • Tear: – Anechoic cleft – Most common anterior Labral Tear – Possible paralabral cyst – Sensitivity 82%, specificity 60%* Acetab Femoral Courtesy of D. Fessell, Ann Arbor, MI *Jin W et al. J Ultrasound Med 2012; 31:439 Head CAM Impingement Femoroacetabular Impingement: • Pincer-type: deep acetabulum • Cam-type – Broad irregular femoral neck – Possible cortical irregularity at US • Associated with anterior labrum tear • Consider dynamic evaluation Note: labral tear (yellow arrow) and Radiology 2005; 236:588 osseous bump (white arrow) Courtesy of M. van Holsbeeck, Detroit, MI 3 Total Hip Hip Arthroplasty: Arthroplasty: • Ultrasound cannot differentiate small effusion • Metal components from post-op change1 demonstrate posterior • Suspect infection: reverberation A Acet Femur – Pseudocapsule > 3.2 mm: 2 • Artifact occurs deep to H Neck suspect infection prosthesis away from > 3.2 – Extra-articular fluid Head mm fluid collection (unlike collection MRI, CT) – Not visualized with Neck arthrography if non- communication 1Weybright PN et al. AJR 2003; 181:215 2AJR 1994; 163:381 Hip Arthroplasty: infection Hip Arthroplasty: infection Superior Inferior Femur Native Coronal Radiograph Femur Teaching Point: Always screen soft tissues about an arthroplasty Sagittal prior to fluoroscopic joint aspiration Metal-on-Metal Arthroplasty: pseudotumor Pathology: • Joint abnormalities Troch • Bursal pathology Cup • Muscle and tendon injury Neck Cup • Snapping hip syndrome • Miscellaneous pathology Anterior Lateral 4 Trochanteric Pain Syndrome: • Most commonly caused by gluteus Trochanteric Bursal Fluid: minimus and medius tendon • Bursal fluid not normally seen abnormalities1 • Trochanteric bursitis: uncommon • Fluid distention: – 20% of symptomatic patients2 – simple fluid: anechoic – Not actually inflamed3 – complicated fluid: mixed echogenicity – Not associated with pain4 1Kong A et al. Eur Rad 2007; 17:1772 2Long SS et al. AJR 2013; 201:1083 3Sylva F et al. Clin Rheumatol 2008; 14:82 4Blankenbaker DG et al. Skeletal Radiol 2008; 37:903 Greater Trochanter Greater Trochanter Yellow arrow = gluteus medius White arrow = Inferior 12 gluteus minimus Axial MRI FACETS: AF = anterior; LF = lateral; SPF = superoposterior; PF = posterior 3 Superior 4 Pfirrmann et al. Radiology 2001; 221:469 Greater Trochanter Greater Trochanter Gluteus Medius Gluteus Minimus Trochanteric TFL ITB Bursa ITB Gmed Gmin Glut Max AF Subgluteus LF Minimus Bursa PF Gmax Subgluteus AF: anterior facet Anterior Posterior Medius LF: lateral facet Bursa PF: posterior facet Yellow arrow = gluteus medius White arrow = gluteus minimus Note: ITB is formed by fascia from gluteus maximus and tensor fascia latae 5 Gluteus Minimus and Medius: Long Axis Gluteus Minimus: Long Axis Gluteus Gluteus Medius Minimus Gmed Gmed Gmed AF Anterior Anterior Facet Facet From: Philippon et al. Orth J Sports Med 2014 Gluteus Medius: Long Axis Trochanteric Bursitis Iliotibial Tract LF PF Lateral Facet Transverse Coronal Trochanteric Bursitis Iliopsoas Bursa: • Hip joint communication in 10% – Increased with hip joint pathology • May extend cephalad into abdomen • May be mistaken for abscess: – Look for hip joint communication Radiology 1995; 197:853 6 Iliopsoas Bursal Fluid Ischial or ischiogluteal Bursa • Uncommon • “Weaver’s Bottom” • Between ischial tuberosity and gluteus maximus IP Femoral Head Axial T1w post-gadolinium Pathology: Gluteal Tendon Pathology: • Joint abnormalities • Tendinosis: hypoechoic, no defects • Bursal pathology • Partial tear: anechoic clefts • Complete tear: discontinuous tendon • Muscle and tendon injury • >2 mm cortical irregularity is associated with • Snapping hip syndrome tendon tear • Miscellaneous pathology – Positive predictive value = 90% (xray)* *Steinert et al. Radiology 2010; 257:754 Gluteus Medius Tendinosis: Gluteus Medius LF LF Short Axis Long Axis AF LF SPF 7 Tendinosis: Gluteus Minimus Tear: Gluteus Medius AF LF AF AF LF LF >2 mm cortical irregularity depth (x-ray) = 90% positive predictive value for gluteus tendon tear Steinert et al. Radiology 2010; 257:754 Post-operative: Gluteus Medius Calcific Tendinosis: Gluteus Medius AF LF LF AF LF SPF LF Long Axis Short Axis Semimembranosus: tendinosis Conjoined Tendons: tendinosis Conjoint Conjoint Tendon Tendon Ischium Ischium SM Long Axis Short Axis Conjoint Tendon Semimembranosus Long Axis 8 Semimembranosus Tear Semimembranosus: remote tear Conjoint Conjoint Tendon Tendon ST ST BF SM Sciatic Nerve Tear Normal Short Axis Rectus Femoris: anatomy Aponeurosis Tear (Indirect Head): Rectus Femoris Short Axis Long Axis Courtesy of Y. Morag, Ann Arbor, MI Rectus Femoris Tear: full-thickness tear Calcific Tendinosis: rectus femoris AIIS Long Axis Abnormal Normal Long Axis 9 Direct Rectus Femoris Tear: full tear, pseudomass Calcific Tendinosis Head • Ultrasound-guided lavage and aspiration • 20 gauge spinal Long Axis needle Short Axis Short Axis Axial T1w post-gado Before After Rectus Femoris Tear: full tear, pseudomass Hematoma: adductors Long Axis Axial Axial T2w Seroma Thigh Splints: • Adductor insertion avulsion syndrome • Proximal - mid femur • Sports-related injuries • Stress fracture, edema AJR 2001; 177:673 Sagittal 10 Adductor Insertion Avulsion Adductor Insertion Avulsion Femur Femur Coronal Plane Transverse Morel-Lavallée Lesion Morel-Lavallée Lesion: • Thigh and hip region Sub-Q Fat • Fluid collection: – Between subcutaneous fat and fascia – Closed de-gloving injury Muscle • Trauma Muscle Muscle Mellado, AJR 2004; 182:1289 Coronal Transverse Normal Pathology: Snapping Hip Syndrome • Joint abnormalities • Painful snap with hip motion • Bursal pathology • Intraarticular • Muscle and tendon injury • Extraarticular: • Snapping hip syndrome – Anterior: iliopsoas tendon • Miscellaneous pathology – Lateral: iliotibial tract or gluteus maximus 11 Iliopsoas Complex A Snapping Hip Syndrome: iliopsoas AIIS • Image long axis to inguinal ligament superior A Ilium to femoral head B • Extension of flexed abducted and externally rotated hip • Abrupt movement of iliopsoas as iliacus muscle interposed between tendon and Pubis bone moves Red: psoas major Femoral Deslandes et al. AJR 2008; 190:576 Orange: medial iliacus fibers Head Short Axis Purple: lateral iliacus fibers From: Guillin R. et al. Eur Rad 2009; 19:995 Snapping Hip Syndrome: iliopsoas Snapping Hip: lateral • Transverse over greater trochanter • Hip external rotation / flexion • Abrupt motion of iliotibial tract or gluteus maximus over greater trochanter Snapping Gluteus Maximus / Iliotibial Band Gluteus Iliotibial Band Medius TFL Gluteus Maximus Pathology: Gluteus Maximus Gmin • Joint abnormalities • Bursal pathology • Muscle and tendon injury • Snapping hip syndrome • Miscellaneous pathology 12 Polymyositis: sartorius Inflammatory Myositis • Acute: variable echogenicity, swollen • Late: – Hyperechoic: fatty infiltration A – Decreased size V • Possible hyperemia • Infection, dermatomyositis, polymyositis Normal Abnormal Transverse Transection Transection Neuroma: Neuroma: • Neuroma formation: sciatic – Disorganized and tangled nerve end – Normal response to nerve transection – US important to determine if symptomatic J Clin Ultrasound 1997; 25:85 Lymph Node: Lymph Node: malignant • Normal: echogenic hilum • Gray scale: – Interfaces with fluid-filled sinuses – Absent echogenic hilum – Not due to fat – Narrow hilum with thick cortex • Abnormal: enlarged, short axis >1.5 cm – Round shape (not oval) Radiology 1992; 183:215 Radiology 1992; 183:215 13 Lymph Node: reactive Lymph Node: