Disclosures: Ankle Tendon Pathology • Consultant: Bioclinica • Advisory Board: 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. Trauma: tendon Suggested Classification System • Overuse, degenerative etiology HIPAA • Tenosynovitis: paratenon inflammation Compliant! – Specific locations • Tendinosis: tendon degeneration • Acute injury • Tendon tear – Avulsions – Partial-thickness – Full-thickness tear • Penetrating injury Khoury NJ et al. MRI of posterior tibial tendon dysfunction AJR 1996; 167:675 Tibialis Posterior Tendon: Tenosynovitis: • Inflammation of paratenon • Medial malleolus • Surrounding fluid – Longitudinal split – Up to 3 mm may be physiologic – Complete tear: rheumatoid arthritis – Subluxation: retinaculum injury • Synovial proliferation • Navicular • Tendon may be normal – Avulsions: diabetic • Inflammatory or reactive Radiographics 1998; 18:325 1 Tenosynovitis: tibialis posterior tendon Tenosynovitis: US • Fluid distending tendon sheath Anterior Posterior – Anechoic or hypoechoic – May be heterogeneous, complex • Synovial hypertrophy: PTT – Hypoechoic – May be isoechoic to tendon Tibia – Variable flow on color Doppler imaging Short Axis Tenosynovitis: ankylosing spondylitis Pitfall: communicating ankle effusion FDL • Flexor hallucis longus tendon sheath PTT • Less common: other medial tendons • Peroneal tendons: indicates Tibia calcaneofibular ligament tear • No pain or hyperemia Short Axis Tendinosis: tibialis posterior Tendinosis: • Tendon degeneration • Not tendinitis: no acute inflammation • Swollen, hypoechoic tendon • Unlike tear: – Tendon fibers still continuous Navicular – No defined clefts Talus Patient #1 Patient #2 2 Tendon Tear Terminology Partial-thickness Tear: tibialis posterior • Interstitial or intrasubstance tear • Partial-thickness tear Tibia • Longitudinal split tear • Full-thickness tear Short Axis Long Axis Longitudinal Split: tibialis posterior Full-thickness CompleteTear: • Complete disruption of tendon fibers • Hypoechoic or anechoic FDL • Transverse: Tibia – Absent tendon fibers • Longitudinal: – Tendon retraction (dynamic imaging) Short Axis Long Axis Full-thickness Tear: tibialis posterior Full-thickness Tendon Tear: • Pitfall: – Tibialis posterior tendon torn & retracted Tibia – Flexor digitorum longus tendon mistaken as intact posterior tibial tendon Contralateral Side Short Axis 3 Full-thickness Tear: tibialis posterior Dislocation: tibialis posterior tendon PTT Right Left PTT FDL Tibia Tibia Long Axis Short Axis Flexor Retinaculum Injury Flexor Hallucis Longus Tendon: • Stenosing tenosynovitis PTT PTT – Behind medial malleolus – Level of os trigonum Tibia – Between hallux sesamoids • Tears: lacerations > spontaneous Tibia – Longitudinal split: Knot of Henry Short Axis to Long Axis Tibialis Posterior Tendon Boruta. Foot Ank Int 1997; 18:243 Flexor Hallucis: screws Tenosynovitis: flexor hallucis longus FHL FHL FHL 1st Proximal 1st Proximal Tibia Phalanx Phalanx Short Axis Long Axis 4 Flexor Hallucis Longus: impingement Peroneal Tendons: • Lateral malleolus – Longitudinal split, complete tear – Subluxation: retinaculum injury • Os peroneum: peroneus longus – Complete tear, os peroneum fracture • 5th metatarsal: peroneus brevis – Avulsion, with aponeurosis Longitudinal Peroneal Tendon Pathology: Tenosynovitis: peroneal tendons PL PB Retrospective: 40 patients with surgery: • 88% peroneus brevis tear • 37% peroneus brevis + longus tears • 33% low lying peroneus brevis muscle • 20% tendon subluxation Fibula • 13% peroneus longus tear J Foot Ankle Surg 2003; 42:250 Peroneus Brevis: Longitudinal Split Peroneal Longitudinal Tears: PB • Incomplete full-thickness tear PL – Tear extends to 2 tendon surfaces PB • “U” shaped or split PB tendon Fibula • Peroneus longus insinuates into gap J Ultrasound Med 1998; 17:525. Short Axis 5 Peroneal Tendon Tears: US Peroneal Tendon: • 54 tendons (5 peroneal): surgery • Subluxation: partially displaced from – US: 100% sensitivity, 93% accuracy1 retromalleolar groove • 60 peroneal tendons: surgery • Dislocation: completely displaced 2 – US: 100% sensitivity, 90% accuracy • Anterior and lateral to fibula • Implies retinaculum injury 1Waitches et al. JUM 1998; 17:249 2Grant et al. 2005; 87;1788 Peroneal Retinaculum Peroneal Tendon Subluxation: • Abnormal movement may only occur dynamically • Predisposes to peroneal tendon tears – Longitudinal split of peroneus brevis • US: examine with dorsiflexion / eversion – 100% accurate diagnosis with US Neustadter et al. AJR 2004; 183:985 Rosenberg et al. AJR 2003; 181:1551 Peroneal Subluxation: dynamic imaging Dislocation: peroneus brevis & longus Posterior Anterior Anterior Posterior Short Axis Short axis 6 Superior Peroneal Retinaculum Injury Superior Peroneal Retinaculum Avulsion PL/B Fib PL/B PL/B Fibula Calcaneus Short Axis to Peroneal Long Axis Short Axis to Tendons Peroneal Tendons Intrasheath Peroneal Subluxation Intrasheath Peroneal Subluxation • Abnormal snapping of peroneal tendons • Type A: • No lateral displacement, intact retinaculum – Peroneal tendon switch position within sheath – No coexisting peroneal tendon tear • Associations: • Type B: – Convex posterior fibula in 92% – Subluxation of peroneus longus tendon into – Tendon tear in 86% longitudinal split of peroneus brevis tendon – Low lying peroneus brevis muscle in 71% J Bone Joint Surg Am 2008; 90:992 J Bone Joint Surg Am 2008; 90:992 J Foot Ankle Surg 2009; 48:323 Intrasheath Peroneal Subluxation: Type A Intrasheath Peroneal Subluxation: Type B Short Axis Short Axis 7 Os Peroneum Fracture Sagittal T2w Os Peroneum Fracture: • Interval fragmentation or fracture • Contraction + compression on cuboid • Separation: > 6 mm (unlike bipartite) • Associated: peroneus longus tear Kalume-Brigido et al. 2007; Radiology 2005; 237:235. Avulsion: peroneus brevis / aponeurosis Fifth Metatarsal Fracture • Avulsion 5th metatarsal – Peroneus brevis tendon – Plantar aponeurosis • May present after ankle trauma Theodorou. Radiology 2003; 226:857 Tenosynovitis: extensor digitorum longus Anterior Tendons: • At tibiotalar joint – Tenosynovitis, tendinosis, tear Axial T2w • Distal: avulsion • Screw impingement • Muscle hernia Axial post-gado 8 Anterior Tibialis: screw Extensor Hallucis: screw ATT ATT Anterior Tibialis: partial tear Muscle Hernia • Cause: trauma, activities, weak fascia • Lower leg: especially anterior tibialis • Swelling with muscle contraction • US: muscle bulge, possible fascial defect – Site of perforating vessel Beggs, AJR 2003; 180:395 Muscle Hernia: anterior tibialis Muscle Hernia: anterior tibialis 9 Muscle Hernia (extensor digitorum): Muscle Hernia: anterior tibialis superficial peroneal nerve entrapment Long Axis Avulsion Fracture: extensor digitorum brevis Extensor Digitorum Brevis Tendon: • Lateral calcaneus – The only tendon to originate at the dorsum of the calcaneus – Avulsion Norfray. AJR 1980; 134:119 Paratenonitis: Achilles Achilles Tendon: • 2 – 6 cm proximal to insertion – Tendinosis – Full-thickness tear • Calcaneal attachment – Tendinosis, tear – Haglund Syndrome Longitudinal 10 Haglund Syndrome Tendinosis: Achilles Long Axis power Doppler Achilles Tendon: partial-thickness tear Achilles Tendon: complete tear • Full-thickness fiber disruption • Herniation of hyperechoic fat into tendon gap • Posterior shadowing at torn tendon ends1 • Non-surgical management:2 – >5 mm diastasis: worse outcomes Long Axis – >10 mm diastasis: higher re-tear rate 1Hartgerink, P et al. Radiology 2001; 220:406 Courtesy of Jon Halperin, 2Westin, O et al. Ortho J Sports Med 2016; Oct 2016 San Diego Achilles Tendon: full-thickness tear Full-thickness Tear: Achilles Calcaneus Long Axis: extended field of view Plantaris Sagittal T2w Short Axis 11 Calcaneus Enthesophyte Avulsion Achilles Tendon: complete tear • Pitfall: misinterpretation of intact plantaris as Achilles fibers Calcaneus • Dynamic imaging: look for – Widening of gap with passive dorsiflexion – Lack of tendon movement across tear – Determine if ends approximate Long axis Achilles Tendon: dynamic imaging Achilles FTT + Intact Plantaris Plantaris Short Axis Long Axis Long Axis Achilles Tendon: partial thickness tear Achilles Tendon: healing tear Prox Distal Prox Distal Long Axis Long Axis 12 Avulsion Fracture: Achilles tendon Take Home Points • Tendon pathology / retinaculum injury Proximal Distal • Dynamic imaging Avulsion Fragment – Peroneal tendon • Dislocation • Intrasheath subluxation – Achilles tendon Calcaneus • Full versus partial thickness tear Long Axis Syllabus on line and other educational material: www.jacobsonmskus.com Twitter handle: @jjacobsn 13.