MSK Radiology & Intro to Fractures (Fall 2024) PDF

MUSCULOSKELETAL RADIOLOGY & INTRO TO FRACTURES R E G A N A L F O R D , PA - C C L I N I C A L M E D I C I N E I – FA L L 2 0 2 4 MANY THANKS TO SARAH BOLANDER. DMSC , PA-C , DFAAPA OBJECTIVES Compare and contrast the following imaging modalities: plain radiography, computed to...

MUSCULOSKELETAL RADIOLOGY & INTRO TO FRACTURES R E G A N A L F O R D , PA - C C L I N I C A L M E D I C I N E I – FA L L 2 0 2 4 MANY THANKS TO SARAH BOLANDER. DMSC , PA-C , DFAAPA OBJECTIVES Compare and contrast the following imaging modalities: plain radiography, computed tomography (CT), magnetic resonance imaging (MRI), bone scan, and ultrasound Outline a systematic approach to musculoskeletal imaging Identify common radiographic findings with fractures Describe a fracture in terms of site, anatomic location, fracture pattern, extent of injury, and amount of displacement Define and identify basic fracture patterns on radiograph: transverse, oblique, spiral, comminuted, torus, compression, greenstick, bowing, intra-articular. Identify basic fracture fragment displacement qualities including angulation, translation, rotation, and complete displacement. Identify concerning clinical findings for open fractures. 2 LECTURE OUTLINE Methods of Imaging Fracture Characteristics Cases –On the exam:You will be expected to describe basic fractures and identify basic characteristics of fractures to the level that we discuss in cases. 3 METHO DS O F IM AGING IONIZING NON-IONIZING  MUSCULOSKELETAL (MSK) IMAGING Radiographic modalities allow viewing of internal structures to guide treatment in addition to history/physical exam findings – Soft tissue (muscle, fat) – Ligaments, tendons, etc – Bones Some methods use ionizing radiation to reveal body’s internal organs & structures – What does “ionizing radiation” mean? Radiation that penetrates tissue and damages DNA, which potentially increases cancer risk (more so in children / fetal tissue) MSK IMAGING METHODS IONIZING NON-IONIZING Plain Radiographs (Xrays) Magnetic Resonance Imaging Computed Tomography Ultrasound Nuclear Scintigraphy *Caution with excessive repeat images  unnecessary radiation 6  RADIOGRAPHY (PLAIN RADIOGRAPHS, X-RAYS) Images obtained by projecting x-ray beams through a subject onto an image detector (film or digital) – Dense tissues/objects absorb more x-ray beams (less passes through to detector) and appear white / “radiopaque” – Less dense tissues have more beams pass through – appears black / “radiolucent” Less Dense More Dense Air Fat Fluid Muscle Bone “radiopaque” “radiolucent” Black Gray White 7  8 Case courtesy of Kevan English, Radiopaedia.org, rID: 182419 Case courtesy of Mohd Radhwan Bin Abidin, Radiopaedia.org, rID: 150811 RADIOGRAPHY INDICATIONS CONSIDERATIONS First-line for many MSK conditions Small amount of radiation – Inexpensive, widely-available Pregnancy = not a – Typically ordered prior to more contraindication; consider advanced imaging (CT scan, MRI) alternative method Trauma (fractures, dislocations) May not be appropriate for exclusively soft tissue injuries Tumors Images can be viewed immediately Arthritis with preliminary interpretation Many – Radiologist will perform definitive interpretation 9 A B A – Stationery Xray machine (patient must go to radiology department) B – portable Xray machine (can be performed at C bedside) C – Mini C-arm (can do Xrays plus fluoroscopy – live action) 10 RADIOGRAPHY VIEWS Based on direction of Xray beam traveling through tissue – Posterior/Anterior (PA) – beam travels posterior to anterior – Anterior/Posterior (AP) –anterior to posterior PA vs AP view depends on structure involved (best accuracy – Lateral / Medial closest to detector) – Obliques – Other site- specific views (ankle mortise, weight bearing, etc) “One view is no view” – 2+ views to fully evaluate for subtle fractures 11 AP view Lateral view Oblique / mortise view “One view is no view” 12 COMPUTED TOMOGRAPHY (CT) CT scan takes multiple x-rays rapidly to recreate internal structures – Images can be manipulated to improve view (“windows”) Iodine-based contrast enhances image density differences – Do not always have to use contrast, which comes in IV, oral, rectal forms (depending on need) “contrast, blood and bone are bright” 14 CT VIEWS = ANATOMICAL PLANES Planes: – Axial/Transverse: horizontal slices (Divides Superior and Inferior) Axial/ – Coronal: Longitudinal slice (Divides Anterior and Posterior) – Sagittal: Longitudinal slice (Divides Right and Left) 15 CT – VIEWS Interpretation: A Axial: looking from the patient’s feet toward the head – “Feet at your face” – ALWAYS B Coronal: patient is facing you C Sagittal: Looking from the side Case courtesy of Dr Roberto Schubert, Radiopaedia.org, rID: 15923 16 CT SCAN PRACTICE https://radiopaedia.org/cases/52597/studies/58511?lang=us - pelvis https://radiopaedia.org/play/43399/entry/774065/case/36676/studies/38239?lang=us - chest (axial, coronal, windows) https://radiopaedia.org/cases/ovarian-mucinous-cystadenofibroma?lang=us - ovarian cyst w mirena iud 17 CT - INDICATIONS Excellent accuracy; specifically for bones: – Occult/subtle fractures not visible on radiography – Fracture healing (especially if concerned for non-union / lack of healing) – Complex fractures (intra-articular, highly comminuted or technically- challenging for surgical repair) – Soft tissue / intra-abdominal RADIATION RISK In most settings, CT scan is typically not first line musculoskeletal imaging modality – High radiation exposure compared to radiography – Expensive – Several potential contraindications (next slide) – Non-portable 19 CT – POSSIBLE CONTRAINDICATIONS Allergy to contrast dye (iodinated) Decreased renal function (depending) – Contrast-associated acute kidney injury may occur Significant metal in area to be imaged – Creates artifact – streaking that obscures view Pregnancy – Concern for harm to fetal tissue; CTs should generally be avoided unless extreme circumstances are present Patient habitus – May need specialized “open” CT scan & inquire to weight limit of table  BONE SCINTIGRAPHY (BONE SCAN) Nuclear medicine technique – Very sensitive for evaluating metabolically active bone – Uses radioisotope tracer to detect metabolic activity of bone lesions “Hot spots” = areas of increased tracer uptake / metabolic activity – Bony malignancy / tumors – Infection, fractures Case courtesy of Dr Henry Knipe, Radiopaedia.org, rID: 31380 21 BONE SCAN INDICATIONS Bone metastases (cancer spread to bone) Primary bone tumors Osteomyelitis (bacterial bone infection) Occult fractures Radiation exposure depends on specific study; avoid in pregnant women/ children when possible 22 MAGNETIC RESONANCE IMAGING (MRI) Uses a strong magnetic field with radiofrequency pulses that are transmitted to receiver coils – No ionizing radiation – Detects changes in tissue water content (inflammation, neoplasm, ischemia, etc) – Computer collects differences in tissue signals (T1 vs T2) & recreates image of structures Gadoliunium-based contrast has less potential for allergy, renal problems Case courtesy of Dr Roberto Schubert, Radiopaedia.org, rID: 16703 Exam time 1.5 – 3 hrs, $$, noisy May require medication for claustrophobia 23 MRI INDICATIONS Evaluation of non-bony tissue – Meniscus, articular cartilage, ligaments, tendons, brain, spinal cord, etc. Can also provide bony detail due to Case courtesy of Mohd Radhwan Bin Abidin, Radiopaedia.org, rID: 147131 inflammation, neoplasm, trauma or ischemia if not visible on CT scan – Avascular necrosis – Osteomyelitis – Malignancy Axial Coronal Sagittal “Feet at your face” 24 MRI CONTRAINDICATIONS Unstable/uncooperative patient Ferromagnetic materials (check with implant manufacturer) – Pacemakers, valves, clips, cochlear implants… – Beds, oxygen tanks, crash carts, keys, etc. – Metallic objects in body (metal foreign body, some tattoo inks, bullets, piercings, shotgun pellets, etc) Many newer implants are not ferromagnetic; can cause artifact 25  ULTRASOUND Sound waves are transmitted into tissues and images are produced by the “bounceback” of soundwaves transmitted to the ultrasound transducer – No ionizing radiation Doppler ultrasound measures blood flow (vascular studies) Minimal use in evaluating bone; quite useful when evaluating soft tissue Case courtesy of Dr Hisham Alwakkaa, Radiopaedia.org, rID: 59999 26 ULTRASOUND INDICATIONS CONTRAINDICATIONS Frequently used in infants / pregnant Few if any; patient preference women for multiple conditions Soft tissue conditions (tendons and muscles) Guided assistance for joint injections, VIDEO HERE? biopsies, soft tissue drainage Operator / skill dependent 27 MUSCULOSKELETAL IMAGING Choice of Imaging: 1. Clinical presentation: history, mechanism of injury (MOI), location of pain 2. Differential Diagnoses 3. Availability of imaging modalities American College of Radiology (ACR) publishes guidelines for imaging – https://www.acr.org/Clinical-Resources/ACR-Appropriateness-Criteria Plain radiography is the initial imaging of choice for most MSK conditions APPROACH TO ORDERING & INTERPRETING RADIOGRAPHS: FRACTURES 29 DO NOT MISS: OPEN FRACTURES Closed fracture = bone fragments do not penetrate overlying skin Bleeding, deep or open wounds over fracture  considered to be open fractures unless proven otherwise – Urgent evaluation by orthopedic specialist  needs extensive washout, IV antibiotics Evaluate all fractures for potential to be open fractures – If a fracture is open, or could be  lead with this information 30 https://orthoinfo.aaos.org/en/diseases--conditions/open-fractures/ FIRST STEPS – CLINICAL HISTORY & ORIENTATION When ordering radiographs or any medical imaging: – Who is this patient? – Why am I ordering this? – What is the mechanism of injury? Is there a potential for a fracture? – When did the injury occur? Compare with old images if present – How quickly does this study need to happen? 31 FIRST STEPS – CLINICAL HISTORY & ORIENTATION When viewing fracture radiographs: – Is this the correct patient? Know your patient and be prepared to discuss history with specialist and supervising physician – Does the study match what I ordered? What do I expect to find? – Is this the correct view and orientation? – Describe what you see: location, fracture characteristics, position 32 Basic Fracture Description -Location of Fracture -Fracture Line Orientation / Pattern -Position LOCATION Which bone? Which part of the bone? Joint involvement / articular extension? Illustrations by Sandra Ehrler. Reproduced with Permission. 34 ARTICULAR EXTENSION Articular extension = fracture involving the joint History of fall with injury to right wrist. Distal radial fracture that extends to intra-articular surface. Case courtesy of Dr Aditya Shetty, Radiopaedia.org, rID: 28755 35 WHERE IS THIS? Case courtesy of Frank Gaillard, Radiopaedia.org, rID: 18281 Radiopaedia.org, rID: 13768 Basic Fracture Description -Location of Fracture -Fracture Line Orientation / Pattern -Position FRACTURE LINE ORIENTATION Transverse – Fracture line runs perpendicular to length Oblique – Fracture line runs at an angle to long axis Spiral – Rotational force; high energy 38  TRANSVERSE Case courtesy of Dr Jeremy Jones, Radiopaedia.org, rID: 6387 39  OB LIQ UE Case courtesy of Dr Piotr Gołofit, Radiopaedia.org, rID: 48267 40  SPIRAL Case courtesy of Dr Andrew Dixon, Radiopaedia.org, 41 rID: 25704 INCOMPLETE FRACTURES Incomplete fractures are more common in children due to pliable periosteum Bowing – Bending of bone without breaking Greenstick – Partial-thickness fracture; cortex/periosteum interrupted on one side Torus / Buckle – Axial load causes “buckling” of cortex and periosteum 42  BOWING 43 Case courtesy of Dr Jeremy Jones, Radiopaedia.org, rID: 44173  TORUS / BUCKLE 44 Case courtesy of Dr Hani Salam, Radiopaedia.org, rID: 9611  GREENSTICK 45 Case courtesy of Dr Hani Salam, Radiopaedia.org, rID: 13297  NUMBER OF SEGMENTS Simple 2 fragments ex. Transverse, oblique, etc. Comminuted More than 2 fragments AKA “shattered” Comminuted 46 Case courtesy of Dr Bruno Di Muzio, Radiopaedia.org, rID: 44044 UNIQUE FRACTURE PATTERNS Impaction – A bone hits an adjacent bone Compression – Vertebral impaction fractures See image – Where is the fracture? 47 Case courtesy of Dr Sajoscha A. Sorrentino, Radiopaedia.org, rID: 20123 UNIQUE FRACTURE PATTERNS Stress (fatigue) – A fracture in a normal bone due to repeated loading (repetitive physical activity: running, weight lifting, etc). 48 FRACTURE PATTERN - SUMMARY Stay tuned for Salter-Harris fractures (covered in peds ortho) Fractures involving the growth plate Fx Types Basic Fracture Description -Location of Fracture -Fracture Line Orientation / Pattern -Bony Position: Basic Terms  POSITION: NON-DISPLACED FRACTURES Many fractures can occur without loss of anatomic alignment = non-displaced fracture – Will typically be symptomatic 51 Case courtesy of Dr Benoudina Samir, Radiopaedia.org, rID: 21948  POSITION: DISPLACED FRACTURES “What happened to the bone during the fracture?” – Description of displacement is based on distal fragment in relation to proximal limb Body is assumed to be in anatomic position Fractured bone/limb may be shortened or lengthened 52 Case courtesy of Bahman Rasuli, Radiopaedia.org, rID: 90137  “Completely displaced transverse fracture of the distal radius and ulna with dorsal displacement and angulation” TRANSLATION, PLEASE! Case courtesy of Bahman Rasuli, Radiopaedia.org, rID: 90137  POSITION: DISPLACED FRACTURES Descriptors of displacement* – Complete displacement Bone moves totally out of alignment to anatomical normal Describe orientation of distal fragment – Angulation “Completely displaced – Translation transverse fracture of the distal radius and ulna – Rotation with dorsal displacement and angulation” Case courtesy of Bahman Rasuli, Radiopaedia.org, rID: 90137 *Based on distal fragment 54  ANGULATION *Description of position is based on distal fragment displacement – Descriptors of displacement Complete displacement Angulation – Angle of deviation from normal bone axis; measured in degrees Dorsal vs volar/palmar angulation Varus / valgus angulation Radial / ulnar angulation Translation Rotation 55 Illustrations by Sandra Ehrler. Reproduced with Permission.  ANGULATION Dorsal angulation of the distal fragment relative to the long axis of the proximal fragment Dorsal “Completely displaced transverse fracture of the distal radius and ulna with dorsal displacement and angulation” Volar / Palmar Volar / Palmar 56 Case courtesy of Bahman Rasuli, Radiopaedia.org, rID: 90137  ANGULATION Volar angulation of the distal fragment relative to the long axis of the proximal fragment Dorsal “Moderately volar angulated fractures traversing the midshaft radius and Volar / Palmar ulna.” Volar / Palmar Dorsal Case courtesy of Anson Chan, Radiopaedia.org, rID: 178086 57  TRANSLATION – Descriptors of displacement Complete displacement Angulation Translation – No deviation from long axis, but bone has been shifted (measured in percent or width) Ex. 25% displaced, 3 mm displaced Rotation 58 Illustrations by Sandra Ehrler. Reproduced with Permission. TRANSLATION Right tibia Transverse fracture Ventral (~80%) and lateral (10%) translation 59  POSITION: DISPLACED FRACTURES *Description of position is based on distal fragment displacement – Descriptors of displacement Complete displacement Angulation Translation Rotation – Twisting of distal fragment relative to proximal portion; difficult to see on radiography – More obvious on clinical examination when looking at joint orientation 60 Illustrations by Sandra Ehrler. Reproduced with Permission.  ROTATION Case courtesy of Assoc Prof Craig Hacking, Radiopaedia.org, rID: 57656  POSITION: DISPLACED FRACTURES *Description of position is based on distal fragment placement. 62 Illustrations by Sandra Ehrler. Reproduced with Permission.  Complete? Yes  displaced How is it fracture displaced? Angulated? Translated? Is the distal fragment displaced relative Rotated? to proximal fragment? No Non-displaced fracture Illustrations by Sandra Ehrler. Reproduced with Permission. 63  “Completely displaced transverse fracture of the distal radius and ulna with dorsal displacement and angulation” Case courtesy of Bahman Rasuli, Radiopaedia.org, rID: 90137 FIRST STEPS – CLINICAL HISTORY FOR MS. ARMSTRONG A 60-year-old woman D. Armstrong presents to the emergency department with right thigh pain, swelling and inability to bear weight on the right leg for the past one hour after she fell while skiing downhill. Physical examination reveals a swollen painful right thigh. Skin is intact circumferentially without open wounds or bleeding noted. Femoral, popliteal and PT/DP pulses are 2+ bilaterally with intact distal sensation. What imaging do we want to order? – Radiographs to include joint above and below 65 MS. ARMSTRONG Is there a fracture? Where is the fracture? – Mid-distal femoral shaft of the right leg = right femoral shaft, distal 1/3 What type of fracture is it? – Spiral 66 FIRST STEPS – CLINICAL HISTORY FOR MR. LEGSTRONG A 25-year-old man H. Legstrong presents to the emergency department with right lower leg pain, swelling and difficulty walking on the right leg. Symptoms started immediately after he kicked his 80” LG OLED TV in a fit of anger after the Denver Broncos lost against the Seattle Seahawks. Physical examination reveals a tender right lower leg with swelling and bruising noted. Skin is intact circumferentially without open wounds or bleeding noted. Popliteal and PT/DP pulses are 2+ bilaterally with intact sensation. What do we want to order? – Radiograph of the right lower leg – Include knee and ankle (joint above / below) 67 MR. LEGSTRONG Describe what you see – Mid-distal third of the right tibia. – Transverse fracture. – No angulation. – Ventral (80%) and lateral (10%) translation 68 Case courtesy of Sajoscha A. Sorrentino, Radiopaedia.org, rID: 15121  MR. SADMAN – URGENT CARE A 59-year-old man is brought by his cycling group to urgent care 30 minutes after his bicycle was struck by a car at 25 miles per hour. He was thrown from his bike and sustained an injury to his lower leg. The patient agreed to be evaluated when he couldn’t finish the day’s ride due to pain. The patient’s PT/DP and popliteal pulses are 2+ bilaterally. Neurologically intact distally. See images for radiography findings and clinical presentation. 69 Radiopaedia.org, rID: 87507; https://www.bmj.com/content/367/bmj.l6246 MR SADMAN Based on the history and physical presentation, which of the following is the most appropriate disposition (management) of this patient? Setting = urgent care. – A – splint the lower extremity with outpatient follow up in orthopedic clinic – B – suture the wound closed and prescribe oral antibiotics – C – wash out the wound and discharge patient with primary care follow up – D – direct the patient to the emergency department for prompt orthopedic evaluation 70  Verify the patient Obtain quality films SUMMARY – Multiple correct views – Joint visualization Be systematic Systematically identity fractures Document vascular and – Compare to unaffected side if needed neuro status of distal Describe fractures as accurately as possible region – Location – Orientation / Pattern / Segments Clinical pearl: if you are sending the patient to the ED and the patient is agreeable, call ahead – Position / Displacement and leave your contact info if the ED provider wishes to speak with you. *Look at your own films and correlate findings with clinical exam 72 REFERENCES Espinosa JA, Nolan TW. Reducing errors made by emergency physicians in interpreting radiographs: longitudinal study. BMJ. 2000;320(7237):737-740. Eng J, Mysko WK, Weller GE, et al. Interpretation of emergency department radiographs a comparison of emergency medicine physicians with radiologists, residents with faculty, and film with digital display. AJR AM J Roentgenol. 2000;175:1233-1238. Martin J, Marsh JL, Nepola JV, Dirchl DR, Hurwitz S, DeCoster TA. Radiographic fracture assessments: which ones can we reliably make? J Orthop Trauma. 2000;14(6):379-385. Bolander, S. A systematic approach to describing fractures. JAAPA. 2019;32(5):23-29. Beutler, et al. General principles of fracture management: bone healing and fracture description. Accessed 2024. Ed. Gammons, Asplund, Grayzel. Wolters-Kluwer: UpToDate. Radiopaedia. http://radiopaedia.org/. Accessed Summer 2024 (June – September), specific cases attributed throughout. Smithuis R. Radiological Society of the Netherlands. Radiology Assistant Educational site. http://www.radiologyassistant.nl. Accessed September 8th, 2024. StatPearls.