Focused Musculoskeletal Ultrasound

Transcription

1 Focused Musculoskeletal Ultrasound David Lewis Consultant Emergency Medicine Ipswich (Club Doctor, Ipswich Town FC) Advanced Emergency Ultrasound

2 Objectives! General principles! Musculoskeletal anatomy! Ultrasound appearance of normal structures! Ultrasound recognition of common musculoskeletal pathology! Introduction to ultrasound guided invasive procedures (practical)

3 General Principles! Equipment Good quality ultrasound platform Image quality vs Portability Linear Transducer! High frequency! Ultrasound beams are all parallel! Can all be orientated perpendicular to the structure of interest

4 Ultrasound Transducers! One size does not fit all 38mm 5-10MHz 9cm 38mm 7-13MHz 6cm 28mm 7-13MHz 6cm 60mm 2-5MHz 22cm Biomicroscope 50MHz

5 Ultrasound Transducers

6 Equipment! Colour / Power Doppler Vessel / Nerve / Tendon Inflammation Neovascularisation Invasive procedure

7 Technique! Choose probe! Copious coupling gel! Alternative techniques Stand-off device

8 Water-Bath Sonography The problem Poor contact between irregular extremity surface and flat transducer surface Superficial structures not within focal zone The solution Water is an excellent acoustic medium Allows stand-off from extremity surface Brings superficial structures into focal zone Improves image quality Reduced discomfort

9 Technique! Split Screen Allows panorama views Allows comparison views

10 Technique! Contralateral comparison Large amount of normal variation exists Numerous musculoskeletal sectional views Abnormality should be present in two planes and not present on contralateral side.

11 Technique! Dynamic Examination The musculoskelatal system is dynamic Structures change in movement! Muscles contract / distract! Tendons slide / separate! Joints move Abnormality not seen on static image may be revealed

12 Anatomy! Superficial layers Skin, Subcutaneous Adipose, Fascia! Intermuscular septum! Neurovascular bundles

13 Anatomy! Muscle is very vascular! Tendons are relatively avascular

14 Anatomy! The structure of tendons change close to the insertion site! enthesis

15 Ultrasound Normal Structures! Skin! Adipose! Tendon! Hyaline Cartilage! Fibrocartilage! Nerve! Muscle! Bone! Ligaments

16 Skin / Adipose! Reverb artefact! Fat is hypoechoic! Connective tissue around adipocytes is hyperechoic! Fatty tissue may be hypo- or hyper-echoic depending on the size of adipocytes

17 Tendon! Parallel longitudinal collagen bundles! Hyperechoic when imaged perpendicularly! Typical fibrillar pattern of parallel internal echoes.! Homogenous fibrocartilagenous insertion

18 Tendon! When obliqued (>5 ), tendons may lose their reflectivity Anisotropy

19 Tendon! Anisotropy can be used to help identify small tendons e.g wrist and ankle

20 Muscle! Hypoechoic bundles! Hyperechoic interfaces of epimysium & perimysium (arrows)! Hyperechoic fatty & connective tissue septae

21 Muscle! Artefact may mimic pathology Vascularity Anisotropy

22 Hyaline Cartilage! Anechoic in children and young adults! Progressively more echogenic in elderly

23 Fibrocartilage! Homogenous densely packed fibres! eg. TFCC Menisci Glenoid Labrum

24 Bone! Hyperechoic cotex with acoustic shadow! Periosteum normally closely adherent to cortex

25 Ligaments! Reflective collagenous fibrillar structures similar to tendons! May be multi-layer with fibrils running in different directions

26 Nerves! More echogenic than muscle! Run between muscle groups! Proximal trunks hollow vessels without flow! Peripheral nerves bundle drinking straws

27 Demo

28 Musculoskeletal Pathology! Trauma Muscle injury Subcutaneous haematoma Foreign body Tendon rupture Bone fracture! Inflammation Tendinopathy! Infection Abscess Cellulitis! Joints Hip Shoulder

29 Muscle Injury Diagnosis! Grade I Strain Overuse / overstretch Stiffness & soreness! Increased echogenicity! Swelling

30 Muscle Injury Diagnosis! Grade 2 Partial tear Intrasubstance tear Pain & loss of function! Discontinuity of muscle fibres in perimysium! Intramuscular fluid collection may be seen with a surrounding hyperechoic halo tendon

31 Muscle Injury Diagnosis! Grade 2! Dynamic scanning during contraction may enhance the size and contrast of the lesion! Hypervascularity may be seen on colour doppler TS Post. Thigh at rest contraction

32 Muscle Injury Diagnosis! Grade 3 Complete tear Violent contraction against resistance! May see complete discontinuity of muscle fibres and associated haematoma LS Ant. Thigh at rest contraction

33 Muscle Injury Diagnosis! Grade 3! Clapper in Bell sign TS Ant. Thigh

34 Muscle Injury Diagnosis! Contusion Blunt injury! Increased echogenicity! Swelling! Crosses myofascial boundary

35 Muscle Injury Diagnosis! Intramuscular Haematoma

36 Muscle Injury Management! Grade 1 recovery 2-3 weeks! Grade 2 recovery 1-2 months! Grade 3 recovery 2-4 months! Grade 3 may require surgery!?suitable for drainage! Follow up scans

37 Subcutaneous Haematoma! Strips adipose off fascia! Often under tension! Leads to ischaemia / ulceration! Often better drained

38 Tendon Injury - TendoAchilles! History / examination! 30-50yrs! Racket sports! cm above insertion! Assoc with chronic tendinopathy! 2. Musculotendinous insertion! 3. At insertion +/- avulsion! Assoc abnormal bone e.g dm, steroids, renal

39 Tendon Injury - TendoAchilles! Full thickness interruption! Space filled with haematoma! Dynamic examination

40 TA Rupture Advanced Emergency Ultrasound

41 TA Rupture Advanced Emergency Ultrasound

42 TA Rupture Advanced Emergency Ultrasound

43 TA Rupture Advanced Emergency Ultrasound

44 Bone Injury! Indications Extension of FAST Occult Fracture Rib Fracture Sternal Fracture! Advantages of Sonography: Early diagnosis

45 Toddler s Fracture Left leg Right leg Right leg Day 1 Right leg Day 14

46 Toddler s Fracture

47 Fracture Reduction! Ultrasound guided haematoma block! Ultrasound guided regional nerve block! Real-time ultrasound assessment of cortical alignment! Real-time ultrasound assessment of joint reduction

48 Inflamation - Tendinopathy! Tendoachilles AP 4-6mm! Patella Tendon AP 3-4mm! Ultrasound Increased size Focal/general hypoechogenicity Hyperaemia Peritendinous fluid Cacification

49 Patellar Tendinopathy Advanced Emergency Ultrasound

50 Patellar Tendinopathy Advanced Emergency Ultrasound

51 Inflamation - Tendinopathy! Paratenonopathy! Osgood Schlatters

52 Infection - Cellulitis / Abscess! Indications Soft Tissue Infection? Collection! Advantages of Sonography: Differentiates abscess from simple cellulitis Guides timing of I&D Guides location of I&D

53 Infection Advanced Emergency Ultrasound

54 Paediatric Hip! Child supine! Align probe along femoral neck by rotating 45 oblique! Identify neck, growth plate and head! Identify hyperechogenic capsule & iliopsoas tendon

55 Paediatric Hip! Normal = concave upwards! Abnormal = convex upwards! 2-4 mm = normal! Asymmetry >2mm! Cause of effusion cannot be differentiated by ultrasound

56 Hip Effusion Advanced Emergency Ultrasound

57 Hip Effusion Advanced Emergency Ultrasound

58 Hip Effusion Advanced Emergency Ultrasound

59 Shoulder! Indications Rotator cuff tears Subacromial bursitis Bicipital tendonitis Gleno-humeral effusion! Use Protocol SubS BG GT

60 Shoulder! Follow intraarticular biceps tendon! Move probe upwards and posterior! Half-Nelson brings SupS anteriorly! More in practical stations Cor Del BT SupS

61 Questions?