AGNES KAWEME FOOT ULTRASOUND • • • • • • • • • • • • • Student: Student Number: Email Address: School: Workplace: Lecturer: Due Date: Agnes Kaweme 17324438 Agnes.kaweme@postgrad.curtin.edu.au Science and Engineering My Radiology Centre (MRC) Perth Le-Anne Grimshaw 26/05/2014 I declare that this assignment is my own work and has not been submitted in any form for another unit, degree or diploma at any university or other institute of tertiary education. Information derived from the published or unpublished work of others has been acknowledged in the text and a list of references is given. I warrant that any disks and or computer files submitted as part of this assignment have been checked for viruses and reported clean. Student Signature: akaweme Date: 30/05/2014 INTRODUCTION Ultrasound is effective in diagnosis of various disorders of the foot. Throughout the semester theoretical and practical knowledge has been gained to assist in developing and improving my technique in foot ultrasound. This portfolio presents a case study from one of the cases I came across which has been beneficial in further developing my skills. NORMAL BONE ANATOMY Structures of the hind foot • • • • • • • Calcaneus – Lies posteriorly forms the heel and lever for the muscles of the calf. Cuboid in shape with 6 articular surfaces- superiorly it supports a fat pad for the Achilles tendon-the posterior surface articulates with the talus- the anterior surface articulates with the cuboid bone, other surfaces serve as attachments for ligaments of the foot of the foot. -It’s the largest bone of the foot- transmits the weight of the body to the ground Talus- second largest tarsal bone in the foot, irregularly shaped- the head of the talus articulates with the navicular, The neck serves as an attachment for ligaments of the foot and the body supports the leg through articulations with the medial and lateral malleolus –rests on the calcaneus Mid foot- 5 Tarsal bones Cuboid- found on the lateral aspect of the foot – pyramid shaped and gives shape to the transverse arch of the foot-articulates with the calcaneus, cuneiform, the 4th and 5th metatarsals and the navicular bone Navicular- found medially 3Cuneiforms – lateral –mid –medial Forefoot - 5 metatarsals-5 proximal phalanges- 5 middle phalanges 4 distal phalanges Joints- Talo-calcaneal joint. -Talo-navicular joint medially, - Calcaneocuboid joint lateral aspect, Transverse tarsal metatarsal joints- 1-5 Metatarsophalangeal joints 1-5 proximal inter- phalangeal joints – 1-4 –distal interphalangeal joints. (Bianchi and Martinoli 2007). TENDONS AND MUSCLES DORSAL ASPECT • Extensor digitorum brevis its an intrinsic wide thin muscle of the dorsum of the foot- originates from the dorsal and lateral surface of the calcaneus- • • inserting on the lateral sides of the extensor digitorum longus tendons of digits 2-4- main action is to extend digits 2-4 Tibialis anterior – originates from the lateral condyle and proximal lateral shaft of the tibia, inserts on the base of the metatarsal 1 and medial cuneiform innervated by the deep Peroneal nerve, its main action is to dorsiflex and inverse the foot Extensor hallucis brevis- originates from the dorsal portion of the calcaneus, inserting on the dorsal surface of the base of the proximal phalanx of digit 1 or the great toe PLANTAR ASPECT FIRST LAYER OF MUSCLES • Flexor digitorum brevis-first layer intrinsic muscle of the plantar surface of the foot-acts on digits 2-5 – originates from the medial process of the calcaneal tuberosity, plantar aponeurosis- inserts on the lateral surfaces of the middle phalanx of digits 2-5- main action is to flex digits 2-5. The muscle is innervated by the medial plantar nerve • Flexor hallucis longus-originates from the inferior two thirds of the posterior fibula and the inferior interosseous membrane –inserting on the inferior surface of the first distal phalanx - main action is to flex the distal phalanx, is innervated by the medial plantar nerve • Abductors hallucis- originates from the flexor retinaculum, medial process of the calcaneal tuberosity, plantar aponeurosis –its an intrinsic muscle of the first layer of medial side of the plantar surface of the footmain action is to abduct digit 1 Innervated by the medial plantar nerve • Abductor digiti minimi-originates from the lateral process of the calcaneal tuberosity and the plantar aponeurosis – inserts on the lateral side of the proximal phalanx of the 5th digit- main action is to abduct and flex the 5th digit (Human anatomy atlas 2014) • SECONDD LAYER OF MUSCLES Quadratus plantae- has two heads originates from the medial and lateral sides of the calcaneus, Insertion - the two portions join and end in a flattened band at the tendon of the flexor digitorum longus, innervated by the medial and the lateral plantar branches. Flexor digitorum longus – originates from the posterior surface of the tibia, insertion is on the inferior surfaces of the distal phalanges 2-5, innervated by the deep Peroneal branch of the tibial nerve, main action is to flex the phalanges of the distal joints 2-5, inversion and plantar flexion of the foot. Lumbricals- originates from the tendons of flexor digitorum longus. Insertion s on the dorsal surface of the proximal phalanges 2-4, innervated by the terminal divisions of the tibial nerve. The first lumbrical innervated by the medial plantar nerve. Second, third and fourth lumbricals by the lateral plantar nerve, main action is to flex the metatarsophalangeal joints. THIRD LAYER OF MUSCLES Flexor hallucis brevis- originates from the plantar surface of the lateral cuneiform and cuboid bones- splits into two parts as it approaches its insertion - to the proximal phalanx of the great toe, innervated by the medial plantar nerve. Adductor hallucis oblique head- originates from the second, third and fourth metatarsals and the tendon sheath of peroneus longus, inserts on the base of the proximal phalanx of the great toe (hallux), innervated by the lateral plantar nerve. The trans verse originates from the plantar metatarsophalangeal ligaments of the third, fourth and fifth digit joints and inserts on the lateral side of the great toe, innervation is by the lateral plantar nerve, main action is to adduct the great toe. Flexor digiti minimi-originates from the base of the fifth metatarsal bone, inserting on the lateral side of the base of the fifth toe, innervated by the superficial branch of the lateral plantar nerve, main action is to flex the metatarsophalangeal joint of the fifth toe (small toe). FOURTH LAYER OF MUSCLES There are three bipennate plantar interossei a combined with the four dorsal interossei – originates from the bases and medial sides of the metatarsals of the third, fourth and fifth digits, inserting on the bases of the proximal phalanx of the third, fourth and fifth digits, innervated by the lateral plantar nerve, main action is to adduct the third, fourth and fifth digits flexing the metatarsophalangeal joints (MTPs) extending the proximal interphalangeal (PIP) joints and distal interphalangeal (DIP) joints LIGAMENTS Plantar fascia- this is a thick hypoechoic, fibrillar band with similar appearance to tendons plantar becomes thin towards the mid and fore foot– originates from the medial tubercle of the calcaneal tuberosity, splits distally inserting on the metatarsal heads. Plantar plates are the main platform for weight bearing; the metatarsal heads provide stability of the metatarsophalangeal joints by resisting dorsiflexion of the foot. Long plantar and plantar calcane0cuboid ligaments arise from the calcaneus to the cuboid. Lateral ligaments -posterior talofibular ligament, posterior tibiofibular ligament, anterior tibiofibular ligament, anteriortalofibular ligament Medial ligaments – posterior tibiofibular part, tibiocalcaneal part, anterior tibiotalar part, tibionavicular part VASCULAR CIRCULATION According to Bianchi and Martinoli (2007,841), The main vascular supply to the foot is by the dorsalis pedis artery. A continuation of the anterior tibial artery (ATA) branches to supply oxygenated blood to the dorsal surface of the foot. A network of superficial veins in the foot form the dorsal venous arch which carry de-oxygenated blood and drains into the great and small saphenous veins through dorsalis pedis vein. The deep plantar venous network from distal to proximal forms the deep venous arch located in the plantar surface of the foot- connects with dorsal metatarsals. The medial and lateral plantar veins navigate posteriorly from the deep plantar arch uniting near the calcaneal region to form the posterior tibial vein. NERVES The foot is innervated by the deep tibial nerve, which divides into the medial and lateral planter nerves: The medial planter nerve further branches into the abductor hallucis nerve, flexor digitorum brevis nerve, 1st lumbrical, medial proper plantar nerve and digital nerves to the 3 1/2 toes The lateral plantar nerve branches into Quadratus plantae nerve, abductor hallucis nerve, interosseous nerve, two to fourth lumbricals and digital nerves to lateral one and half toes (Ebrahaem 2013). The sural nerve is composed of two branches – one from the tibial nerve and the other from the common peroneal nerve. Its distal continuation supplies sensation to the lower lateral leg, lateral heel, ankle and dorsal foot. The deep fibular nerve innervates the extensor digitorum brevis and the first 2 interosseous muscles. INDICATIONS FOR EXAMINATION OF THE FOOT Below are some of the indications for examination of the foot: • • • • • • • • • • • • Sports injuries Chronic pain in the foot- could be hind for plantar fascia, mid or forefoot Muscular, ligament and tendon tears Vascular pathology Lumps and bumps in the foot Arthritis Suspected bony spur Ganglia, lipomas Foot swelling Foot pain- suspected Morton’s neuroma Ultrasound guided joint injections and aspiration Bursitis (Grimshaw 2014) Morton’s Neuroma Morton’s neuroma is a benign growth of the nerve tissue, which develops in the foot, commonly between the third and the fourth toes. It is also known as an intermetatarsal neuroma. It is the thickening of the nerve tissue and located in the ball of the foot. It is caused by compression and irritation of the nerve, which becomes fibrous as a result of acute foot arch, flat feet and wearing high heeled or narrow shoes (Betts et al 2003). Patient history is taken into consideration when diagnosing Morton’s neuroma. Kaminski et al (1997,37) states that ultrasound is helpful in confirming the presence of an enlarged neuroma. CASE STUDY A 29 years old lady presented at our imaging department with a request form for ultrasound of both feet. Clinical findings- Pain on the tarsometatarsal joints, with bony growth on the dorsum of the left foot. The patient was asked questions concerning the on set of symptoms, medical history and current medication she was taking. She confirmed pain had developed in both feet over a period of six months on and off having been on analgesics and anti-inflammatory medication. She described her pain as burning, sometimes numbness in the foot as well as tingling and pricking felt from time to time. She also acknowledged the fact that she used to wear high-heeled shoes prior to her pain starting, found relief in wearing padded shoes. SCANNING TECHNIQUE: Right forefoot The patient was scanned in a sitting position with both plantar aspects of the feet on the couch. The right forefoot was scanned first, from the dorsum aspect starting at the 1st metatarsal phalangeal joint (MTPJ) in longitudinal through to the 5th MTPJ assessing each joint space and extensor tendons. Then the tarsometatarsal joints were assessed from 1st-5th joint spaces, they all appeared normal (refer to images 1-5) The plantar aspect of the foot was scanned with right leg extended and the foot is flexed at the ankle joint to allow easy access to the webspaces 1-2, 2-3 and 3-4. Complex webspaces were demonstrated and compression was applied, 2nd -3rd right webspace was non compressible suggestive of possible presence of a neuroma. The other webspaces were compressible; the complex appearances were possible bursitis (refer to images 6 and 8) Left foot The plantar aspect of the foot was placed on the couch scanning in longitudinal plane from the 1- 5 MTPJ assessing joint spaces and the extensor tendons, which appeared normal. With the leg extended the plantar aspect of the foot was scanned, assessing the web spaces 1-2, 2-3, and 3-4. The 2-3 webspace was pathological in that it was non compressible, possibly due to the presence of a Morton’s neuroma. The 1-2 and 3-4 webspaces appeared hypoechoic but were compressible this could be due to bursal complexes (bursitis) though colour Doppler images is not displayed to show hyperemia. The plantar aspect of both feet were assessed for fibromas and other pathology such as plantar warts RIGHT PLANTA PLATES Image 1 Right foot. Shows 1st MTPJ Image 2 Right foot shows 2nd MTPJ Image 3 Right foot shows 3rd MTPJ Image 4 Right foot shows 4th MTPJ Image 5 Right foot shows 5th MTPJ Image 6 Right foot shows 1st -2nd webspaces Image 7 Right foot- shows 2-3rd webspaces Image 8 Right foot –shows 3-4th webspace Image 10 Right foot – shows 1st TMTJ Image 11 Right foot shows 2nd TMTJ Image 12 Right foot- shows 3rd TMTJ Image 13 Right foot –shows 4th TMTJ Image 14 Right foot –shows 5th TMTJ IMAGES OF THE LEFT FOOT PLANTA PLATES Image 15 Left foot –shows normal 1st MTPJ Image 16 left foot- shows normal 2nd MTPJ Image 17 left foot –shows 3rd MTPJ Image 18-Left foot shows -4th MTPJ Image 19 Left foot – shows normal 5th MTPJ Image 20-Left foot shows 1-2 webspace Image 21-Left foot shows 2nd to 3rd webspace Image 22-Left foot shows 3rd to 4th webspace Image 23 shows 4th webspace Image 24 shows 1st TMTJ REFERENCE Beggs Ian Stefano, Bianchi Michel Cohen, Michel Court-Payen, Andrew Grainger, Franz Kainberger, Andrea Klauser, Carlo Martinoli, Eugene McNally, Philip J. O’Connor, Monique Reijnierse Philip and Remplik Enzo Silvestri.2010. “Musculoskeletal Ultrasound: Technical Guidelines” Insights into Imaging 1:99-141. Bianchi, S., and C. Martinoli. 2007. Ultrasound of the Musculoskeletal System: New York: Springer http://www.curtin.eblib.com.au.dbgw.lis.curtin.edu.au/patron /SearchResults.aspx? q=Bianchi%2CS.%2C+and+C.+Martinoli.+ 2007+ultrasound+of+the+musculoskeletal+system%3ASpring er&t=quick Grimshaw, Le-Anne.2014 “Module seven- ankle and foot.” Lecture notes. https://lms.curtin.edu.au/bbcswebdav/pid1076942-dtcontent-rid-7331507_1/courses/310697- FacSciEng1717724458/module%20seven%20msk%20%20ankle%20and%20foot%202013.pdf Ultrasound of the foot pathology.2014. Ultrasoundpaedia. http://www.ultrasoundpaedia.com/pathology-foot.