ATHLETES: OVERUSE MRI of Overuse INJURIES VERY COMMON Injury in the Elite Athlete • Muscle William B. Morrison, M.D. Associate Professor of • Joints Radiology Thomas Jefferson • Tendon University Hospital Philadelphia, PA USA • Ligament • Bone [email protected] How is this Relevant to My Practice? • High performance athletes get similar injuries as ‘regular’ people… but: – More of them, & at a younger age MUSCLE / SOFT TISSUE – More commonly imaged – Secondary gain involved INJURY • All the cases here are high performance athletes – but most injuries are conventional • Exceptions – Some weird sport-specific patterns of stress and other injuries – Acute injuries as opposed to overuse •Overuse –DOMS Muscle Injury Delayed Onset Muscle • Acute injury Soreness (DOMS) – Tendon – Myotendinous junction • All athletes are susceptible if they – Muscle belly change training regimen • Athletes tend to work out intensely – leads to muscle injury • Rarely imaged (“no pain no gain”) – Weightlifting / aerobic exercise – 24hr later – soreness – Can be severe, even look like a tear 1 Acute Muscle Injury • Direct → muscle belly, esp quadriceps T2 – esp rugby, football • Indirect → myotendinous junction – eccentric contraction – sudden acceleration / DOMS: Lateral gastrocnemius deceleration Finding can be subtle, even with T2 and fat sat Professional football player Acute Injury – T1 Quadriceps hematoma Muscle belly injury Myotendinous Unit Hit with helmet • Myotendinous Junction – ‘weak link’ of normal myotendinous complex T2 – Common place for injury – Most common mechanism: eccentric contraction (muscle lengthens and contracts at the same High time) T1 = blood Gastrocnemius tear: Grade 1 Muscle Strain “V” sign • Ill-defined edema T2 T1 STIR Weishaupt D, JCAT 2001; 25:677 2 Gd Gd can help identify Grade 2 Muscle Strain subtle muscle injury AKA “Partial Tear” STIR Professional baseball player Grade 1 strain Sartorius m. Marathon Runner Quadratus Femoris Strain Small Grade 2 Strain – NFL Player High performance athletes often get routine injuries in unusual locations Grade 3 Muscle Strain Grade 3 Strain • Complete tear Rectus femoris – Fluid, blood common – Retraction – balled up muscle may be perceived as a mass – Degree of dysfunction varies • Hamstrings, rectus femoris, tibialis anterior – loss has little effect on ADL STIR perfomance 3 Sportsman’s Hernia Adductor avulsion Pubic symphysis capsule injury Sportsman’s Hernia Rectus abdominis strain ::Groin pain medially ::Actually a ‘grab bag’ of diagnoses -Adductor injury -Pubic symphysis inj -Rectus abdominis strain -actual hernia Chronic Injury Marathon Runner Bone resorption Loss of cortex Looks like clavicular osteolysis Corresponding MRI Edema only / predominantly at distal clavicle Classic in Weightlifters Other Muscle Pathology Dysfunction related to nerve impingement Compartment syndrome Clavicular Osteolysis 4 Radial Tunnel Syndrome Compartment Syndrome Gd helps find subtle areas of muscle involvement! • Confined fascial compartment – Lower leg > thigh – Most common: anterior compartment • Acute and chronic forms – Acute: tibial fx, hematoma, vascular injury, infection Elbow nerve impingement – Chronic: Muscle hypertrophy / overexertion syndromes -Many types • Increased compartmental pressure (>30mm Hg) -Etiology • Decreased bloodflow into compartment ::muscle hypertrophy (wt lifters) – Clinical: pain/swelling, weakness, decreased sensation ::upper extremity endurance athletes (esp tennis) • Late: Muscle infarction T2 FSE fatsat Chronic Exercise-induced Compartment Syndrome Anterior compartment Pre-Gd Bursitis Gd can help show subtle variations in muscle vascularity Post-Gd Adventitial Bursitis Friction related Exquisitely painful Activity-specific locations TENDONS Professional Ballet dancer Also note stress fx of sesamoid 5 TENDON TENDINOSIS PATHOPHYSIOLOGY • Thickening, increased signal (T1, PD, T2) • Degeneration Example of friction: Distal biceps -primary (overuse injury) Mechanical-pronation leads to impingement between radius -direct frictional effect and ulna • Hypovascular-critical zone – Tendons without sheaths are susceptible • Achilles, biceps, cuff, etc. – Between myotendinous jct and insertion • ‘Normal tendons don’t tear’ Distal biceps -esp in weightlifters 2 TENDON TEAR LATERAL EPICONDYLITIS Adjacent marrow edema -Chronic, severe, refractory cases Epicondylitis ::Especially in racquet / club sports COMPLETE TEAR: USUALLY ::Lateral= tennis elbow ASSOCIATED WITH RETRACTION – e.g., biceps: retracts, bulging muscle (‘popeye’ arm) Muscle edema (esp ECR brevis) IMPINGEMENT MEDIAL EPICONDYLITIS Rotator Cuff • “Golfer’s elbow” Tendinosis and Tear •Lateral acromial downslope: –Predisposes to impingement –Esp. common in overhead throwing sports TEAR 2 6 --Impingement is nearly Undersurface Partial Lesions at the Tendinosis always involved “watershed zone” Hypoxic Degeneration --Underlying degeneration Thickness Tear --“Acute tear” extremely uncommon Professional basketball player Lesions at the Tendinosis “watershed zone” Tendinosis Mucoid Degeneration Painful Enthesopathy Edematous spur =high likelihood of sx Professional basketball player Patellar Tendinosis / Tear Tendinosis / Tear Pro Basketball Player 7 Iliotibial Band Friction Syndrome Long Distance Runner OVERUSE INJURIES IN ADOLESCENT ATHLETES Delayed Union of Apophyses Medial Apophysis Stress Avulsive Stress Ischeal Apophysis Old Osgood-Schlatter Gymnast Extensor mechanism pathology AKA “Jumper’s knee” Esp. common in basketball 8 Cartilage Lesions Microfracture – NBA Player JOINTS Medial compartment symptoms prevent play S/P MICROFRACTURE 7 MONTH FOLLOW-UP 13 MONTHS LATER Playing without Recurrent symptoms symptoms OSTEOCHONDRAL LESIONS OSTEOCHONDRAL LESION OF THE TALUS Panner’s disease Esp. in basketball Esp. in adolescent pitchers 35 month follow up -interval detachment of Chronic osteochondral injury of capitellum fragment Underlying focus of AVN 9 OCD KNEE OCD phalanx Detached Ballet Dancer Professional Baseball Player Synovitis in Elbow Plicas and Bodies POSTERIOR SPURS, INTRA- Posterolateral Elbow Plica ARTICULAR BODIES Baseball Pitcher 10 ANKLE JOINT Impingement Joint Impingement Anterior impingement: and Instability large spurs limit dorsiflexion -esp in soccer, kicking sports Anterolateral Impingement Posterior Impingement Esp. in ballet “meniscus syndrome” “Os Trigonum Syndrome” -following tear of lateral -big os ligaments -fluid at interval -scar tissue forms in recess -leads to impingement, cartilage -cystic change erosion, pain Hip Impingement Posterior Labral Tear Basketball Player Chronic Unidirectional Posterior Instability Subluxation 11 Chronic Multidirectional Instability Combined Anterior and Posterior Instability Capsular Injury ANTERIOR DISLOCATION POSTERIOR CAPSULAR OSSIFICATION “BENNETT LESION” Soccer – capsular “Turf Toe” injury superomedial Football players -esp. due to artificial turf -Tear of plantar plate 1st MTP -Often acute on chronic DORSAL HOOD INJURY Boxer LIGAMENTS FASCIA 12 ELBOW MCL INJURY T T NORMAL MCL partial tear “T sign” CHRONIC INJURY PLANTAR FASCIITIS Flexor tendon pulley injury Esp. in runners Acute on chronic Esp. common in rock climbers Plantar Fascia Medial Tibial Stress Tear Syndrome • AKA “shin splints” • Avulsive injury medial tibial myofascial attachment • Running, overuse • Fascial or periosteal edema along anteromedial tibia • Occasional marrow edema • Most common: normal MRI T2 Anderson MW. Radiology 1997; 207:826 13 Stress Fracture • Fatigue: ‘people in fatigues’ – Normal bone undergoing BONE abnormal stress – Young people • Insufficiency – Abnormal bone (eg, osteoporotic), normal stresses – Older population Etiology of Stress Fracture Stress 40 Response • During early phase of a new 35 no linear component activity, muscle 30 steadily increases 25 muscl e strength 20 bone • Bone must 15 undergo a phase of 10 osteoclastic 5 resorption first 0 12345678 “At risk period” weeks Stress Fracture Stress Fracture Late – Propagation across shaft Atypical locations: periostitis may be mistaken for tumor 14 Tibial Stress Fracture Multiple Foci Stress Classic in runners Fracture Late – Thick periostitis 18 year old male Fatigue fracture Classic Fatigue Fracture Persistent pain in hip 2nd Metatarsal Shaft History of recent increase in activity Olecranon stress in gymnast Atypical Sports-specific Locations 15 GYMNAST WITH DISTAL RADIAL / ULNAR PHYSEAL STRESS Capitate stress Bilaterally Gymnast STRESS Humeral stress pitcher RESPONSE Ballerina Stress forearm in female softball Stress femur player nba 16 Sesamoiditis AVN Sesamoid Likely an end stage of stress T1 T2 -Hyperemia likely due to chronic repetitive injury -Prob along spectrum of stress, AVN -Sesamoid high on T2, STIR surrounding ST edema -Mostly preserved T1 signal T1 T2 AVN metacarpal head (post op) Pro boxer QUESTIONS? Dynamic Gd demonstrates viability of remaining bone 17.