SPORTS ULTRASOUND: EVALUATION OF HAMSTRING INJURIES Mederic M. Hall, MD Associate Professor Departments of Orthopaedics & Rehabilitation, Radiology, and Family Medicine Director of MSK and Sports Ultrasound University of Iowa Sports Medicine
DISCLOSURE Medical Advisory Board, Sonex Health Consultant, Tenex Health Royalties, UpToDate, Inc.
LEARNING OBJECTIVES 1. Understand the complex anatomic relationships of the proximal hamstring tendon complex including the adductor magnus ischiocondylar portion 2. List the important anatomic landmarks of the posterior thigh 3. Understand the variants of posterior thigh muscle/tendon injury commonly seen in the athlete
GENERAL SCANNING TECHNIQUE Transducer selection Begin with survey in transverse/axial plane Know key landmarks for orientation History and physical examination are key to recognition of early or subtle pathology
TRIANGLE OF COHEN HYPERECHOIC TRIANGLE Home base landmark for proximal posterior thigh Conjoint tendon (CJ) lies superficial, semimembranosus (SM) medial, and sciatic nerve (SCN) lateral Medial
PROXIMAL HAMSTRING TENDON Medial Translate proximal from triangle to IT SM moves under CJ to lie deep and lateral at the IT Best evaluated in SAX with confirmation in LAX
PROXIMAL HAMSTRING TENDON GMax IT HS LAX Distal Translate proximal from triangle to IT SM moves under CJ to lie deep and lateral at the IT Best evaluated in SAX with confirmation in LAX
PROXIMAL HAMSTRING TENDON Brasseur JFR 2011
PROXIMAL HAMSTRING TENDON Dynamic scan is key to identification of individual tendons Medial
ADDUCTOR MAGNUS TENDON ISCHIOCONDYLAR PORTION Broski Skel Rad 2016
ADDUCTOR MAGNUS TENDON ISCHIOCONDYLAR PORTION Potential site of pathology Pitfall in diagnosis of proximal hamstring tendon avulsion
ADDUCTOR MAGNUS TENDON ISCHIOCONDYLAR PORTION Identify AM deep and medial to SM tendon Translate medial and proximal to follow tendon to origin at IT Medial
ADDUCTOR MAGNUS TENDON Obey OJS 2016
ADDUCTOR MAGNUS TENDON
SCIATIC NERVE Identify at hyperechoic triangle Follow proximal and/or distal pending clinical presentation Level of quadratus femoris another helpful landmark if more proximal symptoms Medial Medial
HAMSTRING MUSCLES
MYOTENDINOUS JUNCTIONS SEMITENDINOSUS Just below the tendinous insertion, muscular fibers of the ST (arrow) appear at medial aspect of CJ tendon. Medial Brasseur JFR 2011
MYOTENDINOUS JUNCTIONS BICEPS FEMORIS Muscle fibers of BF (arrow) appear a few centimeters below the lateral aspect of CJ tendon. The CJ tendon is visible to the middle third of the thigh and gradually becomes a sagittal fascial aponeurosis located between the two muscles. Medial Brasseur JFR 2011
MYOTENDINOUS JUNCTIONS SEMIMEMBRANOSUS SM has an aponeurotic membrane between the tendon and muscle. The tendon itself corresponds to lateral side of the aponeurosis while the "membrane" is located in the medial aspect stretched between the tendon and the fascia between the AM Medial CJ tendon (solid arrow) has become a fascia between the biceps (laterally) and semitendinosus (medially). SM tendon (arrowhead) and membrane (dotted arrow) to its medial side between the semitendinosus superficially and the adductor magnus deeper Brasseur JFR 2011
MYOTENDINOUS JUNCTIONS SEMIMEMBRANOSUS Arrow SM membrane Arrowhead SM tendon MU muscle fibers of SM Brasseur JFR 2011
MUSCLE BELLY UPPER THIGH In the upper third of the thigh, the ST occupies almost the entire surface of the hamstring. The belly of BF laterally is small at this level and medial muscle fibers of SM have not yet arisen or have a surface of little importance.
MUSCLE BELLY MID THIGH In the middle third of the thigh, the volume of three muscles (SM, ST, and BF) is almost identical Brasseur JFR 2011
MUSCLE BELLY BICEPS FEMORIS SHORT HEAD In the middle third of the thigh is the start of the short biceps (CB) and the femoral insertion (arrowhead) between the biceps (LGB) and quadriceps (Q). The sciatic nerve (arrow) is located in the medial aspect of the intersection of two biceps. Brasseur JFR 2011
ST SIGMOID FASCIAL SEPTUM VEIL Identified as curvilinear concave posterior aponeurosis at superficial medial aspect of ST Extends to deep surface dividing muscle into medial and lateral portions and ends at anterior edge of lateral muscle Useful landmark to readily identify ST muscle Medial Brasseur JFR 2011
MUSCLE BELLY LOWER THIGH ST muscle and tendon (arrow) is smaller than SM and begins to move superficial The long biceps (LB) has become smaller than the short biceps (CB). Brasseur JFR 2011
DISTAL BICEPS FEMORIS The BFL inserts onto the superficial fascia of the BFS analogous to the medial gastrocnemius to the soleus Potential site of injury/disinsertion
DISTAL MYOTENDINOUS JUNCTION Distal myotendinous junction (arrows) of the short biceps (B) and semimembranosus (SM). Note that the lateral gastrocnemius (GL) begins to develop at this level Brasseur JFR 2011
DESMOND SAYS, KNOW YOUR KEY LANDMARKS Hyperechoic triangle of Cohen Membrane of SM ST veil Distal biceps tendon Distal ST tendon over SM
PATHOLOGY Best identified in short axis with confirmation and extension determined in long axis Timing of scan after injury important False negative if too early 36 hours optimal Follow up scans can be helpful Classification confusing Intrinsic vs Extrinsic (historical features and physical exam) Precise location Hematoma Doppler Doppler Continued healing vs reactivation Beware anisotropy
CLASSIFICATION OF INTRINSIC MUSCLE INJURY Mueller-Wohlfahrt BJSM 2013
CLASSIFICATION OF INTRINSIC MUSCLE INJURY MUNICH CONSENSUS CLASSIFICATION Mueller-Wohlfahrt BJSM 2013
CLASSIFICATION OF INTRINSIC MUSCLE INJURY MUNICH CONSENSUS CLASSIFICATION Mueller-Wohlfahrt BJSM 2013
CLASSIFICATION OF INTRINSIC MUSCLE INJURY Patel Clin Rad 2015
CLASSIFICATION OF INTRINSIC MUSCLE INJURY Grade 0 Grade 1 Grade 2 Reversible damage of the muscle fiber No violation of the supporting connective tissue - DOMS Irreversible damage to the muscle fiber No violation of the supporting connective tissue Irreversible damage to a reduced number of muscle fibers Reaching the supporting tissue Hyperechoic hypertrophy (hyper or T2) of muscle Hyperechoic cloud (or hyper T2) without disruption of muscle architecture Hyperechoic breach (or hyper T2) with blurred or irregular edges (sparks) with disorganization of muscle architecture Grade 3 Irreversible damage to a large number of muscle fibers Reaching the supporting tissue + hematoma Musculo-aponeurotic or musculotendinous disinsertion with hematoma Grade 4 Partial or total rupture of a muscle Avulsion or rupture of a muscle bundle with retraction Brasseur JFR 2011
DOES IT MATTER? Hamilton BJSM 2014
TENDINOPATHY PROXIMAL HS TENDINOSIS IT Medial IT Distal
TENDINOPATHY PROXIMAL HS TENDINOSIS IT Medial Medial Note SM enlargement and echotexture change
TENDINOPATHY PROXIMAL HS TENDINOSIS WITH PARTIAL TEAR Proximal Medial Partial thickness intrasubstance tear
TENDINOPATHY ADDUCTOR MAGNUS TENDINOPATHY Distal Add Mg LAX Add Mg SAX Medial
TENDINOPATHY SEMIMEMBRANOSUS MEMEBRANE Medial
MUSCLE INJURY ACUTE Acute Grade 1 injury to superficial fibers of ST Note hyperechoic cloud like appearance without fiber disruption
GRADE 1 MUSCLE INJURY
MUSCLE INJURY ACUTE SM grade 2 tear at proximal MTJ
MUSCLE INJURY ACUTE ST grade 3 tear along aponeurosis with BF Medial Compression of hematoma
MUSCLE INJURY ACUTE Medial More extensive injury involving ST and BF extending from proximal MTJ
MUSCLE INJURY ACUTE Proximal Proximal Lateral Grade 4 avulsion of proximal MTJ
MUSCLE INJURY SUBACUTE Distal Medial Medial Medial
MUSCLE INJURY CHRONIC Medial Chronic ST scar with reactivation (+ Doppler)
TAKE HOME POINTS Detailed understanding of hamstring anatomy required to interpret sonographic findings Key landmarks allow for quick orientation to hamstring anatomy and pathology 36-48 hours post injury ideal time for evaluation Grading of injury confusing and often not helpful clinically Helpful findings to report: precise location and extent of injury, presence of hematoma and size, Doppler flow
SPORTS ULTRASOUND HAMSTRING mederic-hall@uiowa.edu