Greater Trochanter: Anatomy and Pathology Jon A. Jacobson, M.D. Professor of Radiology Director, Division of Musculoskeletal Radiology University of Michigan Disclosures: Consultant: Bioclinica Book Royalties: Elsevier Advisory Panel: GE, Philips Note: all images from the textbook Fundamentals of Musculoskeletal Ultrasound are copyrighted by Elsevier Inc. Greater Trochanter: gluteal tendons Lateral Posterior medius (red) minimus (blue) Greater Trochanter Greater Trochanter Yellow arrow = gluteus medius White arrow = gluteus minimus Inferior 1 2 FACETS: = anterior; = lateral; S = superoposterior; = posterior Pfirrmann et al. Radiology 2001; 221:469 Axial MRI 3 Superior 4 1
Greater Trochanter Subgluteus Medius Bursa Trochanteric Bursa Greater Trochanter TFL Medius Minimus Subgluteus Minimus Bursa Glut Max Yellow arrow = gluteus medius White arrow = gluteus minimus Posterior : anterior facet : lateral facet : posterior facet Minimus and Medius: Long Axis Minimus: Long Axis Medius Minimus Facet Facet From: Philippon et al. Orth J Sports Med 2014 Medius: Long Axis Iliotibial Tract Lateral Facet 2
Trochanteric Pain Syndrome: Most commonly caused by gluteus minimus and medius tendon abnormalities 1 Trochanteric bursitis: uncommon 20% of symptomatic patients 2 Not actually inflamed 3 Not associated with pain 4 1 Kong A et al. Eur Rad 2007; 17:1772 2 Long SS et al. AJR 2013; 201:1083 3 Sylva F et al. Clin Rheumatol 2008; 14:82 4 Blankenbaker DG et al. Skeletal Radiol 2008; 37:903 Trochanteric Bursitis Transverse Trochanteric Bursal Fluid + Glut Min Tear Trochanteric Bursitis Posterior Glut Max Axial Trochanteric Bursitis: Septic Trochanteric Bursa: infection + gas Note posterior location of bursa T1w Greater Trochanter 3
Trochanteric Region Bursae Trochanteric Bursitis Trochanteric: deep to gluteus maximus Subgluteus medius Subgluteus minimus Axial or coronal plane Transverse Arthrogram Muscle and Tendon Injury Tear: Anechoic or hypoechoic defect Partial-thickness tear Full-thickness tear: retraction Tendinosis: Hypoechoic, enlarged No inflammation (not tendinitis) Tendinosis: Medius Gluteal Tendon Pathology: Tendinosis: hypoechoic, no defects Partial tear: anechoic clefts Complete tear: discontinuous tendon >2 mm cortical irregularity (depth) Associated with tendon tear Positive predictive value = 90% (xray)* S *Steinert et al. Radiology 2010; 257:754 4
Medius: tendinosis Tear: Minimus Short Axis Long Axis Tear: Medius Tear: Medius after THA S >2 mm cortical irregularity depth (x-ray) = 90% positive predictive value for gluteus tendon tear Steinert et al. Radiology 2010; 257:754 Post-operative: Medius Calcific Tendinosis: Medius S Long Axis Short Axis 5
Medius Fenestration Greater Trochanter Needle Potential Treatment Algorithm: If bursa: aspirate, inject steroids If tendinosis: Tenotomy or fenestration Inject steroids superficial to tendon 72% of patients significantly improved 1 If tendon tear: platelet-rich plasma injection? Normal 1 Labrosse, et al. 2010 AJR 2010; 194:202 Snapping Hip Syndrome Painful snap with hip motion Intraarticular Extraarticular: : iliopsoas tendon Lateral: iliotibial tract or gluteus maximus Snapping Hip: lateral Transverse over greater trochanter Hip external rotation / flexion Abrupt motion of iliotibial tract or gluteus maximus over greater trochanter Maximus Snapping Maximus / Iliotibial Band Medius TFL Maximus Iliotibial Band Gmin 6
Snapping Hip Syndrome: iliotibial tract Take-home points: Iliotibial Band Gmin Trochanteric anatomy Bursitis: rare Gluteal tendons abnormalities: frequent Snapping hip: dynamic www.jacobsonmskus.com 7